text: Attitude & Heading Reference Systems key performance Gyroscopes & Accelerometers Bias in-run stability. Navigation output from the LT-500 AHRS unit is available in the user interface. The addition of computationally lean onboard sensor fusion algorithms in microcontroller software like the Arduino allows for low-cost hardware implementations of multiple sensors for use in aerospace applications. now i am learning your code for ITG3205_ADXL345 IMU, and i have several questons. This will calculate the attitude and heading for a device with all of the following sensors: compass, gyroscope and accelerometer. CTi Sensors' new industry grade products including AHRS, VRU, and IMU are based on the latest miniature technology of MEMS sensors. Home; Shop. Product Data Sheet AHRS-8 Attitude Heading Reference System Features • Integrated AdaptNav™ adaptive algorithms provide real-time optimization of sensor performance when used in dynamic operating environments • Integrated AdaptNav II™ provides real-time noise characterizations used for drift compensation of. This is currently being tested using a prototype AHRS and EDU for a lycoming engine. IEEE, 2018. As helno says, GPS on the stratux is critical to AHRS performing. Nine-Axis IMU sensor fusion using the AHRS algorithm and neural networks Kolanowski Krzysztof, Swietlicka Aleksandra, Majchrzycki Mateusz, Gugaa Karol, Karo´ n Igor, Andrzej Rybarczyk´ Poznan University of Technology Faculty of Computing Chair of Computer Engineering 60-965 Pozna ´n, ul. From 1992 to 1998 he was a Senior MTS at The Aerospace Corporation. The orientation of the AHRS has three degrees of freedom: it is a function of three independent variables: roll, pitch and yaw angles. This algorithm is based on three axis magnetometers, three axis accelerometers and three axis gyroscopes, so it can estimates the yaw angle at low/none. Alexis gave us STM32 «IoT node» Discovery kits, which feature this AHRS array among the extensive list of on-board sensors. The OpenFlightSolutions AHRS board is a great. Ryan and Miller (2010) used an adaptive bias estimation algorithm in MEMS-based AHRS for pan and tilt surveillance platform. As you are not providing GPS measurements to the system, the Kalman filter will not transition from the Low_Gain_AHRS algorithm to the INS algorithm (as GPS data is needed for this transition to occur - see the function LG_To_INS_Transition_Test, found in SelectState. Lodestar AHRS requires no external aiding and can settle in <15 minutes or less in dynamic conditions. Where electronics enthusiasts find answers. AHRS free download. Orientus is a ruggedized miniature orientation sensor and AHRS that provides accurate orientation under the most demanding conditions. Chan et al. // Create simple AHRS algorithm using the above sensors. provides Low-Power Network Modems Rugged Telemetry systems CoFDM Low-Latency Video Network Protocols North Finding Systems IMU/AHRS/GNSS-INS Hi-Accuracy Inclinometers Customized Navigation Systems Tactical Data/Audio Modems Dedicated Network Protocols Low-Power Miniature IoT devices. For a visual representation of the Direction Cosine Matrix Algorithm, see. SPRINT INS adds advanced Aided Inertial Navigation that runs concurrently with the Lodestar AHRS algorithm. Precise attitude determination is an essential process for aircraft navigation and control. The LT-500 unit meets all standards and certi-fication requirements needed for worldwide maritime navigation equipment. The Madgwick or Mahony algorithms can be used to filter data in real time from these sensors. How It Works: Attitude and Heading Reference System. Colibrys (Switzerland) Ltd, Neuchâtel / SBG Systems, France, 31 July 2013 – with the strong support of Colibrys, SBG Systems presents a brand new range of AHRS and Inertial Navigation Systems called Ekinox Series. This is currently being tested using a prototype AHRS and EDU for a lycoming engine. Arduino/Genuino 101 CurieIMU Orientation Visualiser. The sensor fusion algorithm usually also estimates sensor component calibration parameters while in use to further improve the accuracy of the orientation estimates. The OpenFlightSolutions AHRS board is a great. TRAX2 is the only orientation module that provides two different modes: AHRS or digital compass. GyroLib is a free, open-source Attitude and Heading Reference System (AHRS) library for the Matlab. 2018 IEEE 8th International Conference on Consumer Electronics-Berlin (ICCE-Berlin). An orientation sensor or AHRS that uses Euler Angles will always fail to produce reliable estimates when the pitch angle approaches 90 degrees. Therefore it is advised to keep sensor away from large metallic objects and let sensor still for at least few seconds upon start of recording. Lodestar AHRS for ROV, SPRINT INS for Survey. Our product lines cover multi-MHz bandwidth Magneto-Resistance (MR) based electric current sensors, high performance open source IMU, Real Time Kinematic (RTK) navigation system and centimeter precision positioning services. While the gyroscope is able to determine the orientation of the board, the accelerometer measures the angular velocity of. I have been using the Mahoney algorithm for quite some time with several different IMUs - FreeIMU v4, Altimu-10, DFROBOT 10dof, sparkfun 10724 sensor, mpu-9150 and mpu-9250. This algorithm is based on three axis magnetometers, three axis accelerometers and three axis gyroscopes, so it can estimates the yaw angle at low/none. The algorithm was developed by William Premerlani and Paul Bizard. It makes Cobalt the ideal choice for SWaP-C applications in which operational safety is unavoidable. The goal of the workshop was to help develop technical literacy about these technologies among workshop participants to provide context when encountering CAV technologies. in Anon (ed. IMU Data Fusing: Complementary, Kalman, and Mahony Filter. An accelerometer is subject to dynamic (or external) and static (gravity) accelerations (see my thesis, chapter 5. An attitude and heading reference system (AHRS) consist of a 9-axis system that uses an accelerometer, gyroscope, and magnetometer to compute orientation of the device. An AHRS may form part of a larger inertial navigation system (INS). Attitude and heading reference system (AHRS) is a three dimensional measurement package including micro-inertial measurement units (MIMUs) and magnetic sensors, which can accomplish the real-time attitude control of moving bodies. Anyone who is serious about reading this article is likely familiar with the topic, and the need of data fusing,. Drag Bike FFA super ffa 2016 HD AHRS IRC Sukoharjo 14 Februari 2016 Part 2. In my opinion, Android rotation vector based and Madgwick AHRS based are the best tools, since they are easy to implement and work fast. I was getting +- 8G in all the axes most of the time. The MTi 10-series is a family of highly reliable MEMS-based orientation sensors with a choice of three different integration levels (IMU, VRU or AHRS). III describes the GPS attitude algorithm. Section VI provides con-cluding remarks and a summary. This paper compares Madgwick and Mahony with the basic AHRS approach to estimate the Euler angles and position. 0 Compatible with PC/iOS/Android) for Arduino and More: Amazon. MEMS-based AHRS was designed and used for posture control of robot sh by Hu et al. Attitude & Heading Reference Systems key performance Gyroscopes & Accelerometers Bias in-run stability. them to test new algorithms in the pool without waiting for any manufacturing, while the mechani-cal and electrical teams could dedicate their time to the new vehicle. – AHRS algorithm estimation through quaternion and complementary filter – Euler angle translation of quaternions into position 3. Extended Kalman Filter (EKF)¶ Copter and Plane can use an Extended Kalman Filter (EKF) algorithm to estimate vehicle position, velocity and angular orientation based on rate gyroscopes, accelerometer, compass, GPS, airspeed and barometric pressure measurements. developed gyrocompass algorithm runs in the background even when used as an AAINS. Chan et al. MEMSIC's solid-state MEMS rate sensors, coupled with Kalman filter algorithms are designed to mitigate high drift rates, provide the basis for low-cost, high-performance. VN-100 Velocity Compensation Application Notes Page 4 of 10 1 AHRS Fundamentals An Attitude Heading Reference System (AHRS) is a sensor system that estimates the attitude of a vehicle based upon the combined measurements provided by a 3-axis gyroscope, accelerometer, and magnetometer. The 3DM-GX3-35 has an advanced mode switch that allows the device to switch into direct “AHRS” or “GPS” mode. Joop Brokking 167,875 views. These days, IMU's (Intertial Measurement Units) are used everywhere. Attitude and Heading Reference Systems (AHRS) are based on fusion algorithms for Micro-Electro-Mechanical (MEMS) sensors Systems in order to obtain the position and orientation of a given entity. Section VI provides con-cluding remarks and a summary. The TRAX AHRS is an attitude and heading reference module that provides unparalleled heading accuracy of sub-1° when static, while moving, and when encountering magnetic distortion. Spatial is a ruggedized miniature GPS aided inertial navigation system and AHRS that provides accurate position, velocity, acceleration and orientation under the most demanding conditions. The Seascape UW9XIMU-01 is a high perfor-mance Attitude Heading Reference System (AHRS) for underwater use. MEMS-based AHRS was designed and used for posture control of robot sh by Hu et al. Therefore it is advised to keep sensor away from large metallic objects and let sensor still for at least few seconds upon start of recording. The imu_filter_madgwick package is used to filter and fuse raw data from IMU devices. The LT-500 unit meets all standards and certi-fication requirements needed for worldwide maritime navigation equipment. AHRS Systems Our Attitude and Heading Reference System (AHRS) system provides 3D orientation by integrating gyroscope data and fusing it with accelerometer and magnetometer data with an advanced data fusion algorithm. We chose the Madgwick sensor fusion algorithm using an AHRS (Attitude and Heading Reference System), which comprises a magnetometer, an accelerometer and a gyroscope. FOX AHRS - Attitude and Heading Reference System. If the gyro have too large of a gain, the ahrs algorithm will integrate your twists to more than 90 degrees, and thus you have too large gain. So most probably your algorithm is not suitable for this application. N Gao, M Wang, L Zhao. I have tested the unit in an XA Hexa DIY kit, a 450pro, and now the DIY XA X8 frame. A gyroscope measures angular velocity which, if initial conditions are known, may be inte-grated over time to compute the sensor's orientation [11, 12]. It blends temperature-calibrated accelerometers, gyroscopes, magnetometers and a pressure sensor with an advanced GNSS receiver. arazim Development Ltd. Therefore, the calibration and validation of the AHRS is very important in order to achieve good performance and accuracy. These different sensors can be divided into two groups. al gradient-descent algorithm is seen from its capability to adapt the. The performance of the method is assessed through simulations and compared to an AHRS based on the Extended Kalman Filter (EKF). SPRINT INS adds advanced Aided Inertial Navigation that runs concurrently with the Lodestar AHRS algorithm. This paper presents an Euler-based non-linear complementary filter (CF). This positional information is then further refined with relative (MEMS) sensors and sensor fusion algorithms. com/58zd8b/ljl. Innovations Firm into Research and solve problem's. Introduction R. This AHRS combines temperature calibrated, accelerometers, gyroscope and magnetometers in complex algorithm to release accurate and reliable orientation. both static and dynamic scenarios. Index #|A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z: Index. MEMS-based AHRS was designed and used for posture control of robot sh by Hu et al. And little competition is always helps. This library calculates Roll, Pitch and Yaw angles by using AHRS or IMU algorithms developed by Sebastian. The method can be preformed without any special tools. That means that the sensor fusion algorithm will give the measured roll, pitch and yaw angles then the attitude controller would compare those values with the desired values set on RC and based on the. Extended Kalman Filter (EKF)¶ Copter and Plane can use an Extended Kalman Filter (EKF) algorithm to estimate vehicle position, velocity and angular orientation based on rate gyroscopes, accelerometer, compass, GPS, airspeed and barometric pressure measurements. Ryan and Miller (2010) used an adaptive bias estimation algorithm in MEMS-based AHRS for pan and tilt surveillance platform. It makes Cobalt the ideal choice for SWaP-C applications in which operational safety is unavoidable. The most interesting thing about the MTi-3 is the data fusion algorithm. We will use the Mahony fusion algorithm in this example since it is. Colibrys (Switzerland) Ltd, Neuchâtel / SBG Systems, France, 31 July 2013 – with the strong support of Colibrys, SBG Systems presents a brand new range of AHRS and Inertial Navigation Systems called Ekinox Series. The highly linear sensor performance and auto-adaptive estimation filter algorithm produces extremely accurate computed outputs under real-world dynamic conditions. When GPS is added to an AHRS, the combined system becomes a micro inertial sensors based INS/GPS. A very common application of inertial measurement is to form an attitude and heading indication system, otherwise known as an AHRS (pronounced AY-harz). mini AHRS Portable AHRS systems For GPS combination 3D Virtual reality Using General Description AH100B is a high performance AHRS ( Mini AHRS) with low price , can be widely used i n aircraft model , unmanned aerial vehicles, robots and other high homeostasis electromechanical devices. Product Data Sheet AHRS-8 Attitude Heading Reference System Features • Integrated AdaptNav™ adaptive algorithms provide real-time optimization of sensor performance when used in dynamic operating environments • Integrated AdaptNav II™ provides real-time noise characterizations used for drift compensation of. This is the AHRS version of the Madgwick’s algorithm which uses the magnetometer sensor. The Bibliography (This section is still under development. Each point is compared to the obstacle map to determine wether an obstacle collision will occur. A gyroscope measures angular velocity which, if initial conditions are known, may be inte-grated over time to compute the sensor's orientation [11, 12]. Crossbow is pleased to be selected by Eclipse as the AHRS for their revolutionary high performance aircraft. Algorithms need to be addressed for sure, specifically looking to add information on how an AHRS works with cites, I will add this but need to put the kids to bed now. So most probably your algorithm is not suitable for this application. VN-100 Velocity Compensation Application Notes Page 4 of 10 1 AHRS Fundamentals An Attitude Heading Reference System (AHRS) is a sensor system that estimates the attitude of a vehicle based upon the combined measurements provided by a 3-axis gyroscope, accelerometer, and magnetometer. Collection of Kalman filter links; Our Kalman filter source code. The Crossbow Attitude and Heading Reference System (AHRS 400) provides heading and attitude information. The algorithm development description is broken up into a series of sections that build upon one another, as follows: Coordinate Frames. The AHRS magnetic heading αM is corrected with local magnetic variance ∆αM which can be calculated for a known geographical. I'm looking forward to the new board announced on Kickstarter. The rest of the paper is organized as follows: In Section2, the RTK algorithm, the Madgwick algorithm, the ZUPT algorithm, and the procedure of collecting data are introduced in detail. So most probably your algorithm is not suitable for this application. Aerial Imaging; Coating Solutions; Hyperspectral; Propellers. Advances in Space Research. Redundancy built into the POLAR software allows it to survive individual sensor failures while maintaining accurate. First, accelerometer biases are calibrated, and then two positions are selected for the calibration of gyro biases. 4) the AHRS algorithm is supposed to run at 1000Hz rate. Lodestar AHRS requires no external aiding and can settle in <15 minutes or less in dynamic conditions. algorithm to deliver accurate and reliable navigation and orientation. These AHRS algorithms are also compared with the Kalman-based commercially available AHRS algorithm of Xsens. Orientus is a ruggedized miniature orientation sensor and AHRS that provides accurate orientation under the most demanding conditions. AHRS SES6200-M SES6200-M is a high accuracy orientation sensor that provides accurate orientation under the most demanding condition. There are some time constants within the Madgwick algorithm. Anyone who is serious about reading this article is likely familiar with the topic, and the need of data fusing, and I shouldn't spend more words on this. In this paper, a low-cost micro attitude and heading measurement system using MEMS inertial sensors is researched. The Sparton AHRS-M2 is a micro-sized, light weight, low power Attitude Heading Reference System with a revolutionary built-in adaptive-calibration mode. The attitude information generated by an AHRS is used in many navigation, guidance, and control applications such as pilot-in-the-loop control of manned aircraft. Introduction. This AHRS combines temperature calibrated, accelerometers, gyroscope and magnetometers in complex algorithm to release accurate and reliable orientation. The advantage of the EKF over the simpler complementary filter algorithms (i. Easy 1-Click Apply (UNITED TECHNOLOGIES CORPORATION) Senior Engineering Manager - Flight Controls & Navigation job in Sterling, VA. IMU Data Fusing: Complementary, Kalman, and Mahony Filter. How It Works: Attitude and Heading Reference System. 4g, frequency lower than 10HZ). Six degrees of freedom (DoF) IMU with integrated high-performance FOGs and accelerometers; Groundbreaking sensor fusion algorithm extracts more data than typical Kalman filters. I was not clear about where the issue was. The core of the Kalman filtering algorithm is the state propagation matrix and the weights of the estimate and measurement matrices. AHRS Features. A Sonardyne developed gyrocompass algorithm runs in the background even when used as an AAINS. Users » shimniok » Code » DCM_AHRS » Documentation Michael Shimniok / DCM_AHRS AHRS based on MatrixPilot DCM algorithm; ported from Pololu MinIMU-9 example code in turn based on ArduPilot 1. So most probably your algorithm is not suitable for this application. The open simulation system is based on Python and it assumes some familiarity with GPS and Inertial Measurements Units (IMU). Maybe it is with the precision of the algorithm, or maybe it is because that the original code did not work on a 64-bit machine. mini AHRS Portable AHRS systems For GPS combination 3D Virtual reality Using General Description AH100B is a high performance AHRS ( Mini AHRS) with low price , can be widely used i n aircraft model , unmanned aerial vehicles, robots and other high homeostasis electromechanical devices. A: The RIOX-AHRS has recently been updated with a new algroithm to incorporate even more stable and usefule AHRS functionality. This AHRS algorithm is able to remove the magnetic distortion impact. WitMotion WT901BLECL AHRS MPU9250 10-axis Accelerometer, 3-axis Angular Velocity+Acceleration+Angle+Magnet Field (Low-Consumption Ble4. 3 weeks ago I did some vibration tests with all the motors at half throttle and I realized I really need to properly isolate the IMU. Experiments are carried out in the small-size flight controller and the real world flying test shows the proposed AHRS algorithm is adequate for the real-time estimation of the orientation of a quadrotor. (There are other ways to specify an orientation in space: the direction cosine matrix has nine variables but also six constraints, so it also has three degrees of freedom. algorithm is to take the highest elevation satellites. Using Madgwick's open-sourced AHRS implementation [14], a novel algorithm to ﬁnd distance, velocity, and trajectory was developed as highlighted in Section2. Attitude and heading reference system (AHRS) is a three dimensional measurement package including micro-inertial measurement units (MIMUs) and magnetic sensors, which can accomplish the real-time attitude control of moving bodies. In this %case, since the best results were from angular rate energy detector. AHRS Features. Source from Shenzhen Rion Technology Co. It fuses angular velocities, accelerations, and (optionally) magnetic readings from a generic IMU device into an orientation quaternion, and publishes the fused data on the imu/data topic. The AHRS-8 is a MEMS-based (micro electro-mechanical systems) attitude heading reference system. This type of algorithm differs from the ones used on high-end AHRS systems, and the ultimate quality of performance is highly manufacturer dependent. AHRS SES6200-M SES6200-M is a high accuracy orientation sensor that provides accurate orientation under the most demanding condition. How It Works: Attitude and Heading Reference System. with the Lodestar AHRS algorithm. This conference program is tentative and subject to change. For a better response I suggest you post a link to the particular sensor, the AHRS algorithm you are using, and describe the application you are using it for. Subsequently the results of the study were analyzed to determine the accuracy of featured algorithm. al gradient-descent algorithm is seen from its capability to adapt the. The first part specifies the AHRS algorithm method MADGWICK (only one parameter) or MAHONY (two parameters proportional and integral). MTi 10-series • Proven XKF3 sensor fusion algorithm. An attitude and heading reference system (AHRS) consists of sensors on three axes that provide attitude information for aircraft, including roll, pitch and yaw. When we saw the new LSM9DS0 from ST micro we thought - wow this could really make some wearables super smart. Open source IMU and AHRS sensor fusion algorithms in C, C# and Mathlab. Last updated on August 12, 2019. If the gyro have too large of a gain, the ahrs algorithm will integrate your twists to more than 90 degrees, and thus you have too large gain. The idea is that at all times, the acceleration is an approximation of the gravity, even though there may be some acceleration due to movement and noise. Joop Brokking 167,875 views. (There are other ways to specify an orientation in space: the direction cosine matrix has nine variables but also six constraints, so it also has three degrees of freedom. Attitude & Heading Reference Systems key performance Gyroscopes & Accelerometers Bias in-run stability. This module uses the serial (TTL level). The completely revised SDK contains an easy-to-use MT Manager software tool to configure, record and display the outputs of the IMU/AHRS/GPS in real-time. This is shown in Figure 1. This paper presents an Euler-based non-linear complementary filter (CF). This AHRS combines temperature calibrated, accelerometers, gyroscope and magnetometers in complex algorithm to release accurate and reliable orientation. Teledyne TSS Launches The New Saturn Family Of FOG-based AHRS And INS Systems. Description Usage Arguments Value Author(s) References. Last updated on August 12, 2019. The x-IMU's propriety on-board IMU and AHRS sensor fusion algorithms provide a real-time measurement of orientation relative to the Earth. Big numbers and oversized buttons make it simple to use. How It Works: Attitude and Heading Reference System. inertial systems INERTIAL SYSTEMS • MEMS-Based Navigation & AHRS Systems (NAV) † Attitude, and Heading Reference Systems (AHRS) † Vertical Gyroscopes (VG) † Inertial Measurements Units (IMU) † Rate Gyro and Accelerometer Units (RGA) Crossbow is the leading supplier of solid-state inertial systems for commercial applications. reference system (AHRS), which outputs the pitch, roll and yaw in real time to assist the control unit to balance the aircraft or to perform specific actions. Description. The solution is a combined GNSS-INS that has an onboard GNSS receiver as well as a fully fused Inertial Navigation Solution. Algorithms & Data. So most probably your algorithm is not suitable for this application. As helno says, GPS on the stratux is critical to AHRS performing. This AHRS algorithm is able to remove the magnetic distortion impact. The FSM300 is a self-contained AHRS/IMU module integrating a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer, along with a low-power 32-bit ARM Cortex M0+ MCU running Hillcrest's high-performance sensor hub software stack. Datasheet Manual The 3DM-GX3® -25-OEM is a lower cost, miniature, industrial-grade attitude heading and reference system (AHRS) with integrated magnetometers, and OEM form factor. Lodestar AHRS requires no external aiding and can settle in <15 minutes or less in dynamic conditions. By using the BMI160 sensor module and Hi-Target V30 GNSS receiver, and using Trimble APX15's solution as reference, the testing experiments are provide to compare the performance of the conventional single AHRS algorithm and the Tightly-coupled GNSS/AHRS EKF fusion algorithm, the experimental results show that the proposed GNSS/AHRS EKF. A unique multi-MEMS architecture blends the inputs from dual independent MEMS sensing elements on each axis to deliver precise three-axis outputs of angular rate and acceleration, plus roll, pitch and heading angles. I'm looking forward to the new board announced on Kickstarter. Foot mounted error-free MIMU data is used to evaluate the approaches. Attitude & Heading Reference Systems key performance Gyroscopes & Accelerometers Bias in-run stability. The Matlab AHRS filter fusion algorithm requires the following hardware/scenario specific parameters to be set (which I think is where my problem is stemming from): Accelerometer noise - variance of accelerometer signal noise $(\frac{m}{s^2})^2$. This means that whenever you are interested in measuring dynamic accelerations rather than gravity you have to compensate for gravity. Most AHRS use an accelerometer, gyroscope and a magnetometer. We chose the Madgwick sensor fusion algorithm using an AHRS (Attitude and Heading Reference System), which comprises a magnetometer, an accelerometer and a gyroscope. AMU30 comprises a 10 degree-of-freedom IMU with a three-axis magnetometer, pressure sensor and a sophisticated AHRS algorithm. provides Low-Power Network Modems Rugged Telemetry systems CoFDM Low-Latency Video Network Protocols North Finding Systems IMU/AHRS/GNSS-INS Hi-Accuracy Inclinometers Customized Navigation Systems Tactical Data/Audio Modems Dedicated Network Protocols Low-Power Miniature IoT devices. AMU30 comprises a ten degree-of-freedom IMU with a three-axis magnetometer, pressure sensor and a sophisticated AHRS algorithm. Lodestar AHRS requires no external aiding and can settle in <15 minutes or less in dynamic conditions. Reno Air Races. This filter is designed to produce 3-DOF orientation estimation of a quadrotor with mounted inertial/magnetic sensors. the estimation algorithm, to take into account the di erent reliability and accuracy of sensors on the basis of their statistical characteristics, and to easily exploit all the a priori knowledge on the involved signals. 4g, frequency lower than 10HZ). N Gao, M Wang, L Zhao. The AHRS magnetic heading αM is corrected with local magnetic variance ∆αM which can be calculated for a known geographical. The most interesting thing about the MTi-3 is the data fusion algorithm. This article needs additional citations for verification. Navigation output from the LT-500 AHRS unit is available in the user interface. Xsens MTi 10-Series The 4th generation MTi sets the new industry standard for reliable MEMS-based AHRS, VRU, and IMUs. Member 06-18-2012 11. Cookie Notice. Experiments are carried out in the small-size flight controller and the real world flying test shows the proposed AHRS algorithm is adequate for the real-time estimation of the orientation of a quadrotor. Altitude and Heading Reference System (AHRS) Roll, Pitch and Heading Angle in Dynamic Environments; Enhanced Performance Kalman Filter Algorithm; High Stability MEMS Sensors; High Range Gyro and Accel Options. For a visual representation of the Direction Cosine Matrix Algorithm, see. For an AHRS, sensor data measured by a gyroscope, accelerometer, and magnetometer also known as MIMU (Mag-netic and Inertial Measurement Unit) can be used. Characterization of Derived Angle of Attack and Flight Path Algorithms. Inertial Motion Units (IMUs) are sensors that measure movement in multiple axes. Performance alternative to FOG-based sensors – Compact, lightweight, low cost MEMS unit – Includes 3-axis magnetometer, pressure sensor and AHRS algorithm – Join us at Sensors Expo, booth 446. Bwt901cl Mems Ahrs Wireless Vibration Sensor,Bluetooth Accelerometer Gyroscope,Ce Approved,Lifetime Technical Support , Find Complete Details about Bwt901cl Mems Ahrs Wireless Vibration Sensor,Bluetooth Accelerometer Gyroscope,Ce Approved,Lifetime Technical Support,Accelerometer Industrial,Industrial Vibration Sensor,3 Axis Accelerometer Sensors Prices from Sensors Supplier or Manufacturer. 3 weeks ago I did some vibration tests with all the motors at half throttle and I realized I really need to properly isolate the IMU. It dynamically fuses static accuracy readings of our TCM 3-Axis compass modules with 3-axis gyroscope data. The focus of their paper, however, was on the in uence of magnetic disturbances. The following video shows the result of this interface with the Sebastian Madgwick's AHRS algorithm. AHRS algorithm to provide the initial attitude of our smartphone and utilize the ZUPT algorithm to aid INS to provide positioning results during GNSS outage. This was driving crazy my AHRS code so something had to be done. The Shift is a tactical sailing compass that allows you to easily see your heading and how much you’re headed or lifted. IEEE, 2018. Moog Crossbow announced last week that it has introduced the ANAV300, an Ultra-Compact MEMS Inertial Measurement Unit (IMU) and AHRS (Attitude Heading Reference System) for navigation and guidance. Rotate to Angle (FRC) This same technique can be used to help a robot drive in a straight line. AMU30 comprises a ten degree-of-freedom IMU with a three-axis magnetometer, pressure sensor and a sophisticated AHRS algorithm. Introduction R. It consists of three accelerometers, three rate gyros, a flux-gate compass, and a digital signal processor to process the data and output it on a serial port. algorithm is to take the highest elevation satellites. UAV Drone UAV Drone is a suite of software and hardware which is hosted on Raspberry Pi for the purpose of dro. A MEMS-based Adaptive AHRS for Marine Satellite Tracking Antenna Yunlong Wang âˆ—, Akbar Hussain âˆ—, Mohsen Soltani âˆ— âˆ—Department of Energy Technology, Aalborg University, Esbjerg 6700, Denmark (e-mail: [email protected], [email protected], [email protected]). Create an account Forgot your password? Forgot your username? Hmc matlab Hmc matlab. You can actually pass any accelerometer or magnetometer object which supports the Adafruit unified sensor library in to the AHRS algorithm, and the examples use the 9-DOF, 10-DOF, and LSM9DS0 sensors. Subsequently the results of the study were analyzed to determine the accuracy of featured algorithm. These days, IMU's (Intertial Measurement Units) are used everywhere. PDF | This paper presents a comparison among several state-of-the-art Attitude and Heading Reference Systems (AHRS). So I have two questions about them: Since my data is pre-. III describes the GPS attitude algorithm. It also describes the use of AHRS and a Kalman filter to. The state estimation propagation for the discrete time filter looks like this:. Attitude dynamic accuracy in whole temperature range = 0. Chan et al. In my opinion, Android rotation vector based and Madgwick AHRS based are the best tools, since they are easy to implement and work fast. The new TRAX2 AHRS & digital compass module incorporates PNI's military-grade magnetic sensors with proven sensor fusion and digital compass algorithms to provide accurate direction and orientation in demanding conditions. Altitude and Heading Reference System (AHRS) Roll, Pitch and Heading Angle in Dynamic Environments; Enhanced Performance Kalman Filter Algorithm; High Stability MEMS Sensors; High Range Gyro and Accel Options. As you are not providing GPS measurements to the system, the Kalman filter will not transition from the Low_Gain_AHRS algorithm to the INS algorithm (as GPS data is needed for this transition to occur - see the function LG_To_INS_Transition_Test, found in SelectState. WitMotion WT901BLECL AHRS MPU9250 10-axis Accelerometer, 3-axis Angular Velocity+Acceleration+Angle+Magnet Field (Low-Consumption Ble4. The performance of the AHRS algorithms depends strongly on the strategies used to reject perturbations (sudden accelerations or deformations of the Earth magnetic field) and the ability of the systems to estimate the biases of the. Joop Brokking 167,875 views. It uses the same IMU and algorithm as described in the post above. Home; Archive; Old forums & topics; SparkFun Product Questions; 9 Degrees - Razor IMU - AHRS- software. Sparton AdaptCal™ provides continuous 3D adaptive in-field calibration while Sparton’s AdaptNav™ sensor fusion algorithms allow the system to provide accurate attitude and heading outputs. Riptide chose Sparton’s revolutionary AHRS M-series due to the product’s ability to deliver another level of navigation precision in a very small form factor at low cost. The dissertation of Jesse Lorenzo Pentzer was reviewed and approved∗ by the following: Sean Brennan Associate Professor of Mechanical Engineering Dissertation Adviser, Co-Chair. For a demonstration of what you can do with this data, you can turn an Arduino connected to a MinIMU-9 v5 into an attitude and heading reference system, or AHRS, with this Arduino program. We will use the Mahony fusion algorithm in this example since it is. AHRS/VG Dynamic Attitude App¶. The following study presents the concept of AHRS (Attitude and heading reference system) algorithm, allowing to define the Euler angles. 1 of the License, or (at your option) any later version. arazim Development Ltd. Index Terms— Rail Robot, Rail Inspection, AHRS. Description. Ryan and Miller (2010) used an adaptive bias estimation algorithm in MEMS-based AHRS for pan and tilt surveillance platform. I am just wondering if anyone has had any experience with measuring any of the parameters required for tuning the AHRS sensor fusion output? I appear to be obtaining reasonable results for slow movements but faster movements are proving to be troublesome, thus I think it may have something to do with the sensor parameters I am specifying. These different sensors can be divided into two groups. Introduction. An AHRS (Attitude and Heading Reference System) provides 3D orientation by integrating gyroscopes and fusing this data with accelerometer data and magnetometer data. On one end you have a few AHRS sensors on the market that fully utilize a similar Kalman filter algorithm to that used on the high-end AHRS systems. in Anon (ed. This dual algorithm capability is unique in the market and allows for dual use from one inertial instrument,. The second problem is because on this code we subtract 1G value from z axis, so if we turn on HW vertically we subtract it from x or y axis and. These algorithms can be used for 3D orientation and position estimation of. Navigation output from the LT-500 AHRS unit is available in the user interface. So far the mpu-6050 with the hmc5883l has the best results. Lodestar AHRS can be supplied to suit subsea applications at any depth. Lodestar AHRS requires no external aiding and can settle in <15 minutes or less in dynamic conditions. algorithm with an optimized Levenberg-Marquardt (LM) algorithm to solve the Whaba's problem. None of them give good results becaus. High accuracy attitude estimation. Extended Kalman filter. Do you have an algorithm for AHRS which also includes the GPS track to support the stability of the AHRS in turns? Can the turn switch threshold be used to overcome the 10% duty cycle mentioned in the documentation. Edit 15: Bugfixes in the AHRS algorithm, Quaternion based AHRS Library (Tested on the Sparkfun 9dof IMU's) Tournifreak. The attitude information generated by an AHRS is used in many navigation, guidance, and control applications such as pilot-in-the-loop control of manned aircraft. Xsens MTi 10-Series The 4th generation MTi sets the new industry standard for reliable MEMS-based AHRS, VRU, and IMUs. I was not clear about where the issue was. It has a full sensing range of +/-3g on three axes (X, Y, Z) with a power consumption of 320uA. On aircraft, for example, the AHRS is integrated with an "artificial horizon" screen so that the pilot can determine his current pitch, roll, and yaw relative to straight and level flight. Gyrocompass (AHRS) The in-house design and development of closed loop Fiber Optic Gyroscope allowed GEM elettronica to realize a new family of state-of-the-art Polaris gyrocompass navigation system based on unique strap-down technology. Silicon Sensing Systems will launch a new high performance all-MEMS inertial measurement unit (IMU), AMU30, at Sensors Expo this month. Mahony is more appropriate for very small processors, whereas Madgwick can be more accurate with 9DOF systems at the cost of requiring extra processing power (it isn't appropriate for 6DOF systems. The performance of the AHRS algorithms depends strongly on the strategies used to reject perturbations (sudden accelerations or deformations of the Earth magnetic field) and the ability of the systems to estimate the biases of the. The built-in magnetometer calibration algorithm will compensate for deviation, and the LT-500 AHRS unit will output reliable navigation data. Section VI provides con-cluding remarks and a summary. PDF | This paper presents a comparison among several state-of-the-art Attitude and Heading Reference Systems (AHRS). But since people. By combining this data you can REALLY orient yourself. The AHRS class enables access to basic connectivity and state information, as well as key 6-axis and 9-axis orientation information (yaw, pitch, roll, compass heading, fused (9-axis) heading and magnetic disturbance detection. The company has built an AHRS (Attitude and Heading Reference System) sensor that provides true heading for outdoor use and not electromagnetic interference or magnetic disturbance.


text:
# 5G SA End-to-End¶

Tip

The srsENB supports prototype 5G features for both NSA and SA modes of operation however, these features are no longer under active development. Instead we recommend the srsRAN Project, our ORAN-native 5G CU/DU solution.

srsRAN 4G 22.04 brings 5G SA support to both srsUE and srsENB. 5G SA features can be enabled via the configuration files of both srsUE and srsENB. This application note demonstrates how to configure a 5G SA network using srsRAN 4G, a 3rd-party core (Open5GS) and ZeroMQ (ZMQ). Using ZMQ means there is no need for physical RF-hardware.

## Network & Hardware Overview¶

For this application note, the following hardware and software will be used:

• Dell XPS13 with Ubuntu 20.04.4

• srsRAN 4G 22.04 (or later)

• ZeroMQ

• Open5GS 5G Core

For information on installing ZMQ and using it with srsRAN 4G, see our ZMQ App Note.

### Open5GS¶

Open5GS is a C-language Open Source implementation for 5G Core and EPC. The following links will provide you with the information needed to download and set-up Open5GS so that it is ready to use with srsRAN 4G:

### Configuration¶

To enable 5G SA features, changes need to be made to both the UE and eNB configuration files. This section will outline these.

Example configs are attached here:

Note

22.04.1 brings changes to the rr.conf, coreset0_idx is now a required field under nr_nell_list. If you are using an old config file with the latest update, you will need to add this to your config file.

These config files have been modified to remove certain options that are not essential to this use-case.

### srsUE¶

The Following steps need to be taken to modify the srsUE config file to enable 5G SA features:

• Enable ZMQ

• Enable NR features

• Configure USIM credentials & APN

#### ZMQ¶

To enable ZMQ the following is added to the UE config file:

[rf]
freq_offset = 0
tx_gain = 80
srate = 11.52e6

device_name = zmq
device_args = tx_port=tcp://*:2001,rx_port=tcp://localhost:2000,id=ue,base_srate=11.52e6

Note

A fixed sample rate must be used for 5G SA

The network namespace must also be configured:

[gw]
netns = ue1

#### NR Features¶

Firstly disable the LTE carrier(s):

[rat.eutra]
dl_earfcn = 2850
nof_carriers = 0

Enable the NR band(s) and carrier(s):

[rat.nr]
bands = 3,78
nof_carriers = 1

Lastly, set the release to release-15:

[rrc]
release = 15

#### USIM Credentials & APN¶

The following USIM Credentials are used:

[usim]
mode = soft
algo = milenage
opc  = 63BFA50EE6523365FF14C1F45F88737D
k    = 00112233445566778899aabbccddeeff
imsi = 901700123456780
imei = 353490069873319

The main change here is adjusting the IMSI, so that the correct PLMN is used.

The APN is enabled with the following configuration:

[nas]
apn = srsapn
apn_protocol = ipv4

### Network Namespace¶

It is important to create to appropriate network namespace for the UE when using ZMQ.

To create the network namespace, use:

sudo ip netns add ue1

To verify the new “ue1” netns exists, run:

sudo ip netns list

More information on why this is needed can be found in the ZMQ App Note.

### srsENB¶

The Following steps need to be taken to modify the srsENB config and associated config files to enable 5G SA features:

• enb.conf

• Set correct PLMN

• Enable ZMQ

• rr.conf

• Add 5G cell to cell list, and remove LTE cells

#### enb.conf¶

##### PLMN & MME¶

Setting the PLMN (MCC & MNC) and MME address is done in the following way:

[enb]
enb_id = 0x19B
mcc = 901
mnc = 70
s1c_bind_port = 0
n_prb = 50

The MMC and MNC are set to match the UE and Core. The MME address is configured to allow the eNB to communicate correctly with the AMF and UPF. If this is not changed srsENB and the Core will not connect.

##### ZMQ¶

ZMQ is enabled with the following changes to the config file:

[rf]
rx_gain = 40
tx_gain = 80

# Example for ZMQ-based operation with TCP transport for I/Q samples
device_name = zmq
device_args = fail_on_disconnect=true,tx_port=tcp://*:2000,rx_port=tcp://localhost:2001,id=enb,base_srate=11.52e6

#### rr.conf¶

The 5G NR cell must be added to the rr.conf when operating in 5G SA mode, the existing LTE cells must be removed. This can be done by either commenting them out, or deleting them entirely. In the attached rr.conf file they have been commented out.

The following 5G NR cell configuration is used:

nr_cell_list =
(
{
rf_port = 0;
cell_id = 1;
root_seq_idx = 1;
tac = 7;
pci = 500;
dl_arfcn = 368500;
coreset0_idx = 6;
band = 3;
}
);

### Core¶

As highlighted above, the Open5GS Quickstart Guide provides a comprehensive overview of how to configure Open5GS to run as a 5G Core.

The main modifications needed are:

• Change the TAC in the AMF config to 7

• Check that the NGAP, and GTPU addresses are all correct. This is done in the AMF and UPF config files.

• It is also a good idea to make sure the PLMN values are consistent across all of the above files and the UE config file.

The final step is to register the UE to the list of subscribers through the Open5GS WebUI. The values for each field should match what is in the UE config file, under the [USIM] section.

Note

Make sure to correctly configure the APN, if this is not done correctly the UE will not connect to the internet.

## Set-up The Network¶

### Core¶

Once the steps from the Open5GS Quickstart Guide are followed you do not need to do any more to bring the core online. It will run in the background. Make sure to restart the relevant daemons after making any changes to the config files.

### eNB¶

First run srsENB. In this example srsENB is being run directly from the build folder, with the config files also located there:

sudo ./srsenb enb.conf

If srsENB connects to the core successfully the following (or similar) will be displayed on the console:

---  Software Radio Systems LTE eNodeB  ---

Opening 1 channels in RF device=zmq with args=fail_on_disconnect=true,tx_port=tcp://*:2000,rx_port=tcp://localhost:2001,id=enb,base_srate=11.52e6
Supported RF device list: bladeRF zmq file
CHx base_srate=11.52e6
CHx id=enb
Current sample rate is 1.92 MHz with a base rate of 11.52 MHz (x6 decimation)
NG connection successful
CH0 rx_port=tcp://localhost:2001
CH0 tx_port=tcp://*:2000
CH0 fail_on_disconnect=true

==== eNodeB started ===
Type <t> to view trace
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Setting frequency: DL=1842.5 Mhz, UL=1747.5 MHz for cc_idx=0 nof_prb=52

The NG connection successful message confirms that srsENB has connected to the core.

### UE¶

srsUE can now be run. This is also done directly from within the build folder, with the config file in the same location:

sudo ./srsue ue.conf

If srsUE connects successfully to the network, the following (or similar) should be displayed on the console:

Reading configuration file ue.conf...

Opening 1 channels in RF device=zmq with args=tx_port=tcp://*:2001,rx_port=tcp://localhost:2000,id=ue,base_srate=11.52e6
Supported RF device list: bladeRF zmq file
CHx base_srate=11.52e6
CHx id=ue
Current sample rate is 1.92 MHz with a base rate of 11.52 MHz (x6 decimation)
CH0 rx_port=tcp://localhost:2000
CH0 tx_port=tcp://*:2001
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Current sample rate is 11.52 MHz with a base rate of 11.52 MHz (x1 decimation)
Waiting PHY to initialize... done!

Attaching UE...

Random Access Transmission: prach_occasion=0, preamble_index=0, ra-rnti=0xf, tti=171
Random Access Complete.     c-rnti=0x4601, ta=0
RRC Connected
RRC NR reconfiguration successful.
PDU Session Establishment successful. IP: 10.45.0.2
RRC NR reconfiguration successful.

It is clear that the connection has been made successfully once the UE has been assigned an IP, this is seen in PDU Session Establishment successful. IP: 10.45.0.2. The NR connection is then confirmed with the RRC NR reconfiguration successful. message.

## Testing the Network¶

### PING¶

This is the simplest way to test the network. This will test whether or not the UE and core can successfully communicate.

### iPerf3¶

In this setup the client will run on the UE side with the server on the network side. UDP traffic will be generated at 10Mbps for 60 seconds. When running the iPerf client, we use the UE network namespace and specify the network-side IP address. It is important to start the server first, and then the client.

#### Network-side¶

Start the iPerf server:

iperf3 -s -i 1

This will then listen for traffic coming from the UE.

#### UE-side¶

With the network and the iPerf server up and running, the client can be run from the UE’s network namespace with following command:

sudo ip netns exec ue1 iperf3 -c 10.45.0.1 -b 10M -i 1 -t 60

Traffic will now be sent from the UE to the eNB. This will be shown in both the server and client consoles, and also in the trace for both the UE and the eNB.

#### Example Output¶

Example client iPerf output:

Connecting to host 10.45.0.1, port 5201
[  5] local 10.45.0.3 port 34894 connected to 10.45.0.1 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  1.30 MBytes  10.9 Mbits/sec    0   90.5 KBytes
[  5]   1.00-2.00   sec  1.12 MBytes  9.44 Mbits/sec    8   55.1 KBytes
[  5]   2.00-3.00   sec  1.25 MBytes  10.5 Mbits/sec    4   50.9 KBytes
[  5]   3.00-4.00   sec  1.00 MBytes  8.39 Mbits/sec    4   43.8 KBytes
[  5]   4.00-5.00   sec  1.00 MBytes  8.39 Mbits/sec    0   58.0 KBytes
[  5]   5.00-6.00   sec  1.25 MBytes  10.5 Mbits/sec    5   53.7 KBytes

Example server iPerf output:

-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 10.45.0.3, port 34892
[  5] local 10.45.0.1 port 5201 connected to 10.45.0.3 port 34894
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  1.13 MBytes  9.44 Mbits/sec
[  5]   1.00-2.00   sec  1.16 MBytes  9.69 Mbits/sec
[  5]   2.00-3.00   sec  1.06 MBytes  8.88 Mbits/sec
[  5]   3.00-4.00   sec  1.05 MBytes  8.78 Mbits/sec
[  5]   4.00-5.00   sec  1.05 MBytes  8.78 Mbits/sec
[  5]   5.00-6.00   sec  1.16 MBytes  9.75 Mbits/sec

### UE Trace¶

The following example trace was taken from the srsUE console while running the above iPerf3 test:

---------Signal-----------|-----------------DL-----------------|-----------UL-----------
rat  pci  rsrp   pl   cfo | mcs  snr  iter  brate  bler  ta_us | mcs   buff  brate  bler
nr  500    29    0  -16u |  28  n/a   1.1   9.9M    0%    0.0 |  28    48k   9.5M    0%
nr  500    25    0  -18u |  27   70   1.1    13M    0%    0.0 |  28    61k    13M    0%
nr  500    28    0  -16u |  27   70   1.1    11M    0%    0.0 |  28   6.7k    12M    0%
nr  500    30    0  -14u |  28   70   1.1   9.2M    0%    0.0 |  28    48k   9.6M    0%
nr  500    26    0  -13u |  27   71   1.1    12M    0%    0.0 |  28    30k    12M    0%
nr  500    31    0  -17u |  27  n/a   1.1   8.8M    0%    0.0 |  28    43k   8.8M    0%
nr  500    29    0  -14u |  27   70   1.1   9.9M    0%    0.0 |  28    52k    10M    0%
nr  500    27    0 -7.0u |  27   70   1.1    11M    0%    0.0 |  28    47k    11M    0%
nr  500    26    0  -14u |  27   71   1.1    11M    0%    0.0 |  28    57k    12M    0%
nr  500    27    0  -16u |  27   70   1.1    11M    0%    0.0 |  28    49k    12M    0%
nr  500    28    0  -10u |  27   71   1.1    11M    0%    0.0 |  28    41k    11M    0%

### eNB/ gNB Trace¶

The following example trace was taken from the srsENB console at the same time period as the srsUE trace shown above:

           -----------------DL----------------|-------------------------UL-------------------------
rat  pci rnti  cqi  ri  mcs  brate   ok  nok  (%) | pusch  pucch  phr  mcs  brate   ok  nok  (%)    bsr
nr    0 4601   15   0   27    11M  296    0   0% |  66.2   99.9    0   28    10M  268    0   0%    0.0
nr    0 4601   15   0   27    10M  289    0   0% |  65.7   99.9    0   28    10M  264    0   0%    0.0
nr    0 4601   15   0   28   9.4M  262    0   0% |  65.0   99.9    0   28   9.5M  242    0   0%    0.0
nr    0 4601   15   0   27    11M  305    0   0% |  66.3   99.9    0   28    11M  278    0   0%    0.0
nr    0 4601   15   0   27    12M  339    0   0% |  66.4   99.9    0   28    13M  340    0   0%    0.0
nr    0 4601   15   0   28   9.6M  265    0   0% |  66.0   99.9    0   28    10M  263    0   0%    0.0
nr    0 4601   15   0   27    11M  310    0   0% |  65.6   99.9    0   28    11M  278    0   0%    0.0
nr    0 4601   15   0   27   9.7M  272    0   0% |  65.9   99.9    0   28   9.6M  245    0   0%    0.0
nr    0 4601   15   0   27   9.3M  260    0   0% |  65.8   99.9    0   28   9.5M  243    0   0%    0.0
nr    0 4601   15   0   27    11M  322    0   0% |  66.1   99.9    0   28    12M  302    0   0%    0.0
nr    0 4601   15   0   27   9.8M  274    0   0% |  65.8   99.9    0   28    10M  267    0   0%    0.0

format: plain


text:
Public Deliverables

Public deliverables

Deliverable 2.1 - Characterisation of raw materials for sorption enhanced gasification
This document describes the analytical techniques that were used and will be used along the project to perform the characterization of the different raw materials to be used in the gasification process. It includes the description of the techniques used for the characterization of fuels and those necessary to perform the characterization of sorbents. In addition, the full characterization of fuels and sorbents to be used in the project are also reported. It is concluded that the selected fuels can be processed in the available experimental rigs although some difference have been found between the natural biomass fuels and ECOH biomass. Regarding to the sorbents, their behavior has been similar to data found in the literature.


text:
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.FSTTCS.2009.2335
URN: urn:nbn:de:0030-drops-23357
URL: http://drops.dagstuhl.de/opus/volltexte/2009/2335/
 Go to the corresponding LIPIcs Volume Portal

### Recurrence and Transience for Probabilistic Automata

 pdf-format:

### Abstract

In a context of $\omega$-regular specifications for infinite execution sequences, the classical B\"uchi condition, or repeated liveness condition, asks that an accepting state is visited infinitely often. In this paper, we show that in a probabilistic context it is relevant to strengthen this infinitely often condition. An execution path is now accepting if the \emph{proportion} of time spent on an accepting state does not go to zero as the length of the path goes to infinity. We introduce associated notions of recurrence and transience for non-homogeneous finite Markov chains and study the computational complexity of the associated problems. As Probabilistic B\"uchi Automata (PBA) have been an attempt to generalize B\"uchi automata to a probabilistic context, we define a class of Constrained Probabilistic Automata with our new accepting condition on runs. The accepted language is defined by the requirement that the measure of the set of accepting runs is positive (probable semantics) or equals 1 (almost-sure semantics). In contrast to the PBA case, we prove that the emptiness problem for the language of a constrained probabilistic B\"uchi automaton with the probable semantics is decidable.

### BibTeX - Entry

@InProceedings{tracol_et_al:LIPIcs:2009:2335,
author =	{Mathieu Tracol and Christel Baier and Marcus Gr{\"o}sser},
title =	{{Recurrence and Transience for Probabilistic Automata}},
booktitle =	{IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science},
pages =	{395--406},
series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN =	{978-3-939897-13-2},
ISSN =	{1868-8969},
year =	{2009},
volume =	{4},
editor =	{Ravi Kannan and K. Narayan Kumar},
publisher =	{Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},


text:
# How to use "Component-Based Game Object System"

## Recommended Posts

Hi guys, I've surveyed component-based game object system for a long time and created one for my current project. I know its idea is dividing functionalities of game objects to several components to prevent deep class hierarchy. However, I still cannot figure out how to build my game upon component-based system. For example, a character (controlled by player) fires a RPG. Then rocket flies over the sky, hits the building and then explodes. How do I code these events and logics into components? Assume that the character, RPG, and rocket are game objects. Following is my approach
GameObject* character = scene->createGameObject("player", "character.xml");
character->getComponent<CharacterLogic>()->fireWeapon("RPG");

and somewhere inside CharacterLogic::fireWeapon(), there is a piece of code like this
GameObject* rpg = _scene->getGameObject("rocket");
rpg->getComponent<RpgLogic>()->fire();

Inside RpgLogic::fire()
GameObject* rocket = _scene->createGameObject(some_obj_name, "bullet_rocket.xml");

rocket->setPosition( this->getObject()->getPosition() + _offset );
rocket->getComponent<RigidPhysics>()->setVelocity( this->getObject()->getOrientation()*Vector3::AxisX()*_rocketSpeed );

There is a component RocketLogic inside the rocket. When RigidPhysics component of the rocket detects collision between the rocket and some other objects, it will send a message and notify RocketLogic component. So RocketLogic calls its member function RocketLogic::onContact() to trigger explosion effect.
//inside RocketLogic::onContact()
GameObject* explosionEffect = _scene->createGameObject( some_obj_name, "explosion.xml" );
explosionEffect->getComponent<ParticleEffect>()->run();
//I don't known whether it is appropriate to implement the explosion effect as a game object

I've noticed that my design has many drawbacks. Every time you need to do some operation, you have to call getComponent with a specific component type as template arguments. So it takes some time for game object to find the component. (look up hash_map ) And if the specified component ( by getComponent ) doesn't exists in the game object, we need to do some error handling, and thus causing a lot of error handling code in my program. Could anyone give me some suggestion?

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I use a messagesystem, with it you can simply send a message to any component and if the component nows the message it will react to it. To continue your example, you could send a message "FireWeapon" with an parameter RPG. Your component would get the message and the parameter and would then create the rocket. Also you could store more information into the message, like the point it was fired etc.
This of course has some drawbacks, mainly that you cant be sure a component understood your message, also it can make your code a lot less typesafe, depending on you implementation of the message system.

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I've been using a component system for the last 3 games I've worked on. Yes I have the same lookup/down-casting code. I usually try to store pointers to components for use later on.

You could keep a CharacterLogic* around for use whenever the character needs to fire its weapon. An RpgLogic* could be kept in the CharacterLogic class so that fire() may be called on it, and the RpgLogic* could be swapped out with another instance whenever the character's weapon is changed.

As for error handling, I've gotten by with throwing exceptions for missing components and for trying to add a new component with the same name as an old component. What sort of errors are you handling beyond this?

My scene nodes are your game objects and my scene node properties are your components.
SceneNodeProperty& SceneNode::AddSceneNodeProperty(const std::string& name, SceneNode::SceneNodePropertyPtr scenenodeproperty){        if(properties.find(name)==properties.end()){                properties.insert(SceneNodeProperties::value_type(name, scenenodeproperty));                return *scenenodeproperty;        }else{                throw SceneNodePropertyAlreadyExists(name.c_str());        }}SceneNodeProperty& SceneNode::GetSceneNodeProperty(const std::string& name)const{        if(properties.find(name)!=properties.end()){                return *properties.find(name)->second;        }else{                throw SceneNodePropertyDoesNotExist(name.c_str());        }}

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As long as you are very careful about when components might be changed or freed ( do it all at once at end of frame simulation, for instance, then you can keep pointers around for speed.

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I have another issue encountered recently for my component-based framework.

Since there are many kinds of weapons in my game, I create an "abstract" component (It's an abstract class) called ComWeaponLogic, and there are derived components implemented for each kind of weapons. For example,
class ComRpgLogic : public ComWeaponLogic
.

However, if I want to get the component pointer from weapon game object, I must name all derived weapon logic component to the same string, eg. "weapon". Then, I retrieve the weapon logic component like this
GameObject* go = _scene->getObject( weaponName );ComWeaponLogic* weapon = static_cast<ComWeaponLogic*>(go->getComponent("weapon"));
.

I not sure whether it is suitable to make all derived weapon components have the same name. This kind of solution is wired. Although, this kind of problem may be solved by message passing pattern, I still concern about the speed of routing message.

Any opinion?

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Quote:
 Original post by alvinsay...I not sure whether it is suitable to make all derived weapon components have the same name. This kind of solution is wired. ...
The name is used as a kind of type system. As such the common "weapon" denotes a base-type for all weapons, regardless which one is the actually used specialization of the weapon component. Why should that be wired? E.g. all OOP languages have such a mechanism.

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I find myself using the strategy pattern here a lot. This way the strategy[weapon] can be selected at runtime. I'm of the opinion that this more closely follows the open/closed principle.

Your example would translate something like this.
class Component{    public:    virtual ~Component(){}};class IWeapon{    public:    virtual void Fire()=0;};class WeaponComponent: public Component{    IWeapon& weapon;    public:    WeaponComponent(IWeapon& weapon):weapon(weapon){}    IWeapon& GetWeapon(){        return weapon;    }    const IWeapon& GetWeapon()const{        return weapon;    }};class RPGWeapon: public IWeapon{    public:    void Fire(){        GameObject* rocket = _scene->createGameObject(some_obj_name, "bullet_rocket.xml");        rocket->setPosition( this->getObject()->getPosition() + _offset );        rocket->getComponent<RigidPhysics>()->setVelocity( this->getObject()->getOrientation()*Vector3::AxisX()*_rocketSpeed );    }};class PistolWeapon: public IWeapon{    public:    void Fire(){        //however your pistol fires    }};

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text:
International
Tables for
Crystallography
Volume B
Reciprocal space
Edited by U. Shmueli

International Tables for Crystallography (2010). Vol. B, ch. 1.5, p. 175   | 1 | 2 |

Section 1.5.1. List of abbreviations and symbols

M. I. Aroyoa* and H. Wondratschekb

aDepartamento de Fisíca de la Materia Condensada, Facultad de Cienca y Technología, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain , and bInstitut für Kristallographie, Universität, D-76128 Karlsruhe, Germany
Correspondence e-mail:  wmpararm@lg.ehu.es

1.5.1. List of abbreviations and symbols

| top | pdf |

 BC Bradley & Cracknell (1972) CDML Cracknell, Davies, Miller & Love (1979) IT A International Tables for Crystallography, Volume A (2005) irreps Irreducible representations L; Vector lattice of a space group ; reciprocal lattice of t Vector of the lattice L of k Vector of the reciprocal space K Vector of the reciprocal lattice [see Note (1)] Basis vectors of the crystal lattice; basis vectors of the reciprocal lattice Row of basis vectors [see Note (2)] Column of basis vectors of the reciprocal lattice X Point of point space Point coordinates; vector coefficients x; r Column of point coordinates; column of vector coefficients Row of coefficients of a reciprocal-space vector [see Note (2)] Lengths of the basis vectors of the lattice Parameters of k-vector coefficients in CDML Lengths of the basis vectors of the reciprocal lattice M, R, D, S Matrices W Matrix part of a mapping w Column part of a mapping (A, a), (W, w) Matrix–column pairs ; ; Group or space group; symmorphic space group; reciprocal-space group Translation subgroup of or ; Point group; holohedral point group Site-symmetry group ; Little co-group of k; little group of k , , Group elements of , , Symmetry operations (Matrix) representation of the group

Notes: (1) In crystallography, vectors are designated by lower-case bold-face letters. With K we make an exception in order to follow the tradition of physics. A crystallographic alternative could be . (2) In crystallography, point coordinates or vector coefficients are written as columns. Therefore, columns are taken as `normal'. In order to distinguish rows from columns (the coefficients of vectors in reciprocal space, i.e. the Miller indices, and the basis of the crystal lattice are written as rows), rows are regarded as transposed columns and are thus marked by .

References

International Tables for Crystallography (2005). Vol. A, Space-Group Symmetry, edited by Th. Hahn, 5th ed. Heidelberg: Springer.
Bradley, C. J. & Cracknell, A. P. (1972). The Mathematical Theory of Symmetry in Solids: Representation Theory for Point Groups and Space Groups. Oxford: Clarendon Press.
Cracknell, A. P., Davies, B. L., Miller, S. C. & Love, W. F. (1979). Kronecker Product Tables, Vol. 1, General Introduction and Tables of Irreducible Representations of Space Groups. New York: IFI/Plenum.


text:
# How to prove that text is linearly separable?

I sentiment analisys task, for this I used SVM with an rbf kernel and a linear one. The results for the linear kernel were better than the rbf, from this I know that text is linearly separable, but how can I provide a formal proof of this?.

You can't formally prove this, unless you happen to be able to fit a hard margin SVM on your data (unlikely). However, intuitively, text representations are high dimensional (bag of words, n-grams, ...). The higher the dimensionality, the easier it is to linearly separate data, as the VC dimension of a linear classifier in $d$ dimensions is $d+1$ (e.g. see these slides). The VC dimension is the largest amount of points that a classifier can shatter (separate).


text:
Bihar Board 12th Physics Objective Answers Chapter 12 Atoms

Bihar Board 12th Physics Objective Questions and Answers

Bihar Board 12th Physics Objective Answers Chapter 12 Atoms

Question 1.
In Geiger-Marsden scattering experiment, the trajectory traced by an a-particle depends on
(a) number of collision
(b) number of scattered a-particles
(c) impact parameter
(d) none of these
(c) impact parameter

Question 2.
In the Geiger-Marsden scattering experiment, in case of head-on collision the impact parameter should be
(a) maximum
(b) minimum
(c) infinite
(d) zero
(b) minimum

Question 3.
Rutherford’s experiments suggested that the size of the nucleus is about
(a) 10-14 m to 10-12 m
(b) 10-15 m to 10-13 m
(c) 10-15 m to 10-14 m
(d) 10-15 m to 10-12 m
(c) 10-15 m to 10-14 m

Question 4.
In an atom the ratio of radius of orbit of electron to the radius of nucleus is
(a) 103
(b) 104
(c) 105
(d) 106
(c) 105

Question 5.
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about
(a) 101
(b) 105
(c) 1010
(d) 1015
(d) 1015

Question 6.
The first spectral series was discovered by
(a) Balmer
(b) Lyman
(c) Paschen
(d) Pfund
(a) Balmer

Question 7.
Which of the following spectral series falls within the visible range of electromagnetic radiation?
(a) Lyman series
(b) Balmer series
(c) Paschen series
(d) Pfund series
(b) Balmer series

Question 8.
The shortest wavelength present in the Paschen series of spectral lines is
(a) 720 nm
(b) 790 nm
(c) 800 nm
(d) 820 nm
(d) 820 nm

Question 9.
The shortest wavelength in the Balmer series is (R = 1.097 x 107 m-1)
(a) 200 nm
(b) 256.8 nm
(c) 300 nm
(d) 364.6 nm
(d) 364.6 nm

Question 10.
The wavelength limit present in the Pfund series is (R = 1.097 x 107 m s-1)
(a) 1572 nm
(b) 1898 nm
(c) 2278 nm
(d) 2535 nm
(c) 2278 nm

Question 11.
When an electron jumps from the fourth orbit to the second orbit, one gets the
(a) second line of Paschen series
(b) second line of Balmer series
(c) first line of Pfund series
(d) second line of Lyman series
(b) second line of Balmer series

Question 12.
When an atomic gas or vapour is excited at low pressure, by passing an electric current through it then
(a) emission spectrum is observed
(b) absorption spectrum is observed
(c) band spectrum is observed
(d) both (b) and (c)
(a) emission spectrum is observed

Question 13.
In Balmer series of emission spectrum of hydrogen, first four lines with different wavelength Ha, Hp, Hy and H5 are obtained. Which line has maxium frequency out of these?
(a) Hα
(b) Hβ
(c) Hγ
(d) Hδ
(d) Hδ

Question 14.
Hydrogen atom emits light when it changes from n = 5 energy level to n =2 energy level. Which colour of light would the atom emit?
(a) red
(b) yellow
(c) green
(d) violet
(d) violet

Question 15.
The wavelength of the first line of Lyman series is 1215 kA, the wavelength of first line of Balmer series will be
(a) 4545 A
(b) 5295 A
(c) 6561 A
(d) 6750 A
(c) 6561 A

Question 16.
According to Bohr’s theory, the wave number of last line of Balmer series is (R = 1.1 x 107 m-1)
(a) 5.5 x 105 m-1
(b) 4.4 x 107 m-1
(c) 2.75 x 106 m-1
(d) 2.75 x 108 m-1
(c) 2.75 x 106 m-1

Question 17.
What is the ratio of the shortest wavelength of the Balmer series to the shortest wavelength of the Lyman series?
(a) 4 : 1
(b) 4 : 3
(c) 4 : 9
(d) 5 : 9
(a) 4 : 1

Question 18.
The Bohr model of atoms
(a) assumes that the angular momentum of electrons is quantized.
(b) uses Einstein’s photoelectric equation.
(c) predicts continuous emission spectra for atoms.
(d) predicts the same emission spectra for all types of atoms.
(a) assumes that the angular momentum of electrons is quantized.

Question 19.
The angular speed of the electron in the nth orbit of Bohr’s hydrogen atom is
(a) directly proportional to n
(b) inversely proportional to $$\sqrt{n}$$
(c) inversely proportional to n2
(d) inversely proportional to. n3
(d) inversely proportional to. n3

Question 20.
The moment of momentum for an electron in second orbit of hydrogen atom as per Bohr’s model is
$$(a) \frac{h}{\pi} (b) 2 \pi h (c) \frac{2 h}{\pi} (d) \frac{\pi}{h}$$
$$(a) \frac{h}{\pi}$$

Question 21.
According to second postulate of Bohr model, the angular momentum (Ln) of nth possible orbit of hydrogen atom is given by
(b)

Question 22.
The total energy (En) of the electron in the stationary states in the nth orbit of the hydrogen atom is

(b)

Question 23.
The radius of nth orbit rn in terms of Bohr radius (a0) for a hydrogen atom is given by the relation
$$(a) n a_{0} (b) \sqrt{n} a_{0} (c) n^{2} a_{0} (d) n^{3} a_{0}$$
$$(c) n^{2} a_{0}$$

Question 24.
In the Bohr model of the hydrogen atom, the lowest orbit corresponds to
(a) infinite energy
(b) maximum energy
(c) minimum energy
(d) zero energy
(c) minimum energy

Question 25.
The value of ionisation energy of the hydrogen atom is
(a) 3.4 eV
(b) 10.4eV
(c) 12.09 eV
(d) 13.6 eV
(d) 13.6 eV

Question 26.
Energy is absorbed in the hydrogen atom giving absorption spectra when transition takes place from
(a) n = 1 → n’ where n >1
(b) n = 2 → 1
(c) n → n
(d) n → n’ = ∞
(a) n = 1 → n’ where n >1

Question 27.
In which of the following systems will the radius of the first orbit (n –1) be minimum?
(a) doubly ionized lithium
(b) singly ionized helium
(c) deuterium atom
(d) hydrogen atom
(a) doubly ionized lithium

Question 28.
When an electron falls from a higher energy to a lower energy level the difference in the energies appears in the form of
(c) both electromagnetic and thermal radiations
(d) none of these

Question 29.
From quantisation of angular momentum, one gets for hydrogen atom, the raius of the nth orbit as
$$r_{n}=\left(\frac{n^{2}}{m_{e}}\right)\left(\frac{h}{2 \pi}\right)^{2}\left(\frac{4 \pi^{2} \varepsilon_{0}}{e^{2}}\right)$$
For a hydrogen like atom of atomic number Z,
(a) the radius of the first orbit will be same
(b) rn will be greater for larger Z values
(c) rn will be smaller for larger Z values
(d) none of these
(c) rn will be smaller for larger Z values

Question 30.
If E is the energy of nth orbit of hydrogen atom the energy of nth orbit of He atom will be
(a) E
(b) 2E
(c) 3E
(d) 4E
(d) 4E

Question 31.
In which of the following Bohr’s orbit (n) a hydrogen atom emits the photons of lowest frequency?
(a) n = 2 to n = 1
(b) n = 4 to n = 2
(c) n = 4 to n = 1
(d) n = 4 to n = 3
(d) n = 4 to n = 3

Question 32.
If an electron is revolving in its Bohr orbit having Bohr radius of 0.529 A, then the radius of third orbit is
(a) 4234 nm
(b) 4496 A
(c) 4.761 A
(d) 5125nm
(c) 4.761 A

Question 33.
The energy required to excite an electron in hydrogen atom to its first excited state is
(a) 8.5eV
(b) 10.2eV
(c) 12.7eV
(d) 13.6eV
(b) 10.2eV

Question 34.
A triply ionized beryllium (Be3+) has the same orbital radius as the ground state of hydrogen. Then the quantum state n of Be3+ is
(a) n = 1
(b) n = 2
(c) n = 3
(d) n = 4
(b) n = 2

Question 35.
The ground state energy of hydrogen atom is -13.6 e V. The kinetic of the electron in this state is
(a) 2.18 x I0-14 J
(b) 2.18 x 10-16 J
(c) 2.18 x 10-18 J
(d) 2.18 x 10-19 J
(c) 2.18 x 10-18 J

Question 36.
If the radius of inner most electronic orbit of a hydrogen atom is 5.3 x 10-11 m, then the radii of n = 2 orbit is
(a) 1.12 A
(b) 2.12 A
(c) 3.22 A
(d) 4.54 A
(b) 2.12 A

Question 37.
A hydrogen atom initially in the ground level absorbs a photon and is excitied to n = 4 level then the wavelength of photon is
(a) 790 A
(b) 870 A
(c) 970A
(d) 1070 A
(b) 870 A

Question 38.
If speed of electron in ground state energy level is 2.2 x 106 m s-1, then its speed in fourth excited state will be
(a) 6.8 x 106 m s-1
(b) 8.8 x 106 m s-1
(c) 5.5 x 105 m s-1
(d) 5.5 x 106 m s-1
(c) 5.5 x 105 m s-1

Question 39.
An electron is revolving in the /Ith orbit of radius 4.2 A, then the value of n is (r1 = 0.529 A)
(a) 4
(b) 5
(c) 6
(d) 3
(d) 3

Question 40.
The ratio of the speed of the electron in the ground state of hydrogen atom to the speed of light in vacuum is
$$(a) \frac{1}{2} (b) \frac{2}{237} (c) \frac{1}{137} (d) \frac{1}{237}$$
$$(c) \frac{1}{137}$$

Question 41.
The binding energy of an electron in the ground state of He is equal to 24.6 eV. The energy required to remove both the electrons is
(a) 49.2 eV
(b) 54.4eV
(c) 79eV
(d) 108.8 eV
(c) 79eV

Question 42.
The ionization energy of Li++ is equal to
(a) 9 hcR
(b) 6 hcR
(c) 2 hcR
(d) hcR
(a) 9 hcR

Question 43.
The de-Broglie wavelength of an electron in the first Bohr orbit is
(a) equal to one-fourth the circumference of the first orbit
(b) equal to half the circumference of first orbit
(c) equal to twice the circumference of first orbit
(d) equal to the circumference of the first orbit
(d) equal to the circumference of the first orbit

Question 44.
The excitation energy of Lyman last line is
(a) the same as ionisation energy
(b) the same as the last absorption line in Lyman series
(c) both (a) and (b)
(d) different from (a) and (b)
(c) both (a) and (b)

Question 45.
The number of de Broglie wavelengths contained in the second Bohr orbit of Hydrgen atom is
(a) 1
(b) 2
(c) 3
(d) 4
(b) 2

Question 46.
If there are N atoms in a source of Laser light and each atom is emitting light with intensity I, then the total intensity produced by it is
(a) NI
(b) N2I
(C) N3I
(d) N4I
(b) N2I

Question 47.
The acronym LASER stands for
(a) Light Amplification by Stimulated Emission of Radiation
(b) Light Amplitude by Stimulated Emission of Radiation
(c) Light Amplification by Strong Emission of Radiation
(d) Light Amplification by Stimulated Emission of Radiowave
(a) Light Amplification by Stimulated Emission of Radiation

Question 48.
Two H atoms in the ground state collide inelastically. The maximum amount by which their combined kinetic energy is reduced is
(a) 10.2 eV
(b) 20.4eV
(c) 13.6eV
(d) 27.2eV
(a) 10.2 eV

Hints & Explanations

Question 4.
(c) The radius of orbit of electrons = 10-10 m radius of nucleus = 10-15 m
Ratio = $$=\frac{10^{-10}}{10^{-15}}=10^{5}$$
Hence the radius of electron orbit is 105 times larger than the radius of nucleus.

Question 5.

Question 8.
(d) The wavelength for Paschen series,

Question 9.
(d) Wavelength for Balmer series is $$\frac{1}{\lambda}=R\left(\frac{1}{2^{2}}-\frac{1} at n = ∞, the limit of the series observed. Question 10. (c) The wavelength for Pfund series is given by Question 15. (c) Here, λL. = 1215 A, For the first line of Lyman series. Question 20. (a) According to Bohr’s second postulate Angular momentum, [latex]L=\frac{n h}{2 \pi}$$

Angular momentum is also called a moment of momentum.

For second orbit, n = 2 $$L=\frac{2 h}{2 \pi}=\frac{h}{\pi}$$

Question 23.
(c) The radius of nth orbit rn = n2 $$\frac{\hbar^{2} 4 \pi \varepsilon_{0}}{m e^{2}}$$ where $$\frac{\hbar^{2} 4 \pi \varepsilon_{0}}{m e^{2}}=a_{0}[/ltaex] (Bohr radius) Hence, rn = n2 a0. Question 30. (d) Since Bohr’s formula for energy in nth orbit is Question 31. (d) The energy level diagram schematically looks like this. As we move to higher and higher levels, the energy increases, but the energy gap between any two levels decreases. Hence in the transition from n = 4 to n = 3, energy released will be E4 – E3. And in the transition from n = 2 to n – 1, energy released is E2 -E1. Now as E4 – E3 < E2 – E1 [latex]\Rightarrow h v_{43}<h v_{21} \Rightarrow h v_{43}<h v_{21}$$

Question 32.
(c) As rn = n2 a0
Here, a0 = 0.529 A and n = 3
.-. rn=3 = (3)3 a0 = 9 x 0.529A = 4.76lA

Question 33.
(b) Energy, $$E_{n}=-\frac{13.6}{n^{2}} \mathrm{eV}$$

Question 34.
(b) Radius of nlh orbit in hydrogen like atom is
$$r_{n}=\frac{a_{0} n^{2}}{Z}$$

where a0 is the Bohr’s radius For hydrogen atom, Z= 1
∴ r1 = a0 (∵ n = 1 for ground state) 2
For $$\mathrm{Be}^{3+}, \mathrm{Z}=4 ∴ r_{n}=\frac{a_{0} n^{2}}{4}$$
According to given problem $$r_{1}=r_{n} \Rightarrow a_{0}=\frac{n^{2} a_{0}}{4}$$
⇒ n = 2

Question 35.
(c) Here the ground state energy, (E) = – 13.6 eV
Since, K.E. of the electron = -E = 13.6 eV
= 13.6 x 1.6 x 10-19 J
= 21.76 x 10-19 J
= 2.18 x 10-18 J.

Question 36.

Question 37.
(c) Here, = 1, and n2 = 4
Energy of photon absorbed, E = E2 – E1

Question 38.
(c) According to Bohr’s model $$v=\frac{2 \mathrm{Ke}^{2} \mathrm{Z}}{n h} \text { or } v \propto \frac{1}{n}$$

Question 39.

Question 40.
(c) Speed of the electron in the ground state of hydrogen atom is
$$v=\frac{2 \pi e^{2}}{4 \pi \varepsilon_{0} h}=\frac{c}{137}=c \alpha$$

where, c = speed of light in vacuum, $$\alpha=\frac{e^{2}}{2 \varepsilon_{0} h c}$$ the fine structure constant. It is a pure number whose value is $$\frac{1}{137}$$.

∴ $$\frac{v}{c}=\frac{1}{137}$$

Question 41.
(c) The energy needed to remove one electron from the ground state of He = 24.6 eV.
As the He+ is now hydrogen-like, ionisation energy
$$=|-13.6| \frac{2^{2}}{1^{2}} \mathrm{eV} \Rightarrow \mathrm{E}=54.4 \mathrm{eV}$$

∴ To remove both the electrons, energy needed = (54.4 + 24.6) eV = 79. eV

Question 48.
(a) In inelastic collision kinetic energy is not conserved so some part of K.E. is lost.

∴ Reduction in K.E. = K.E. before collision – K.E. after collision
Now, since initial K.E. of each of two hydrogen atoms in ground state = 13.6 eV
Total K.E. of both Hydrogen atom before collision = 2x 13.6 = 27.2 eV
If one H atom goes over to first excited state (n1 = 2) and other remains in ground state (n2 = 1) then their combined K.E. after collision is
$$=\frac{13.6}{(2)^{2}}+\frac{13.6}{(1)^{2}}=3.4+13.6=17 \mathrm{eV}$$
Hence reduction in K.E. = 27.2 – 17 = 10.2 eVA


text:
### Home > CALC > Chapter 8 > Lesson 8.3.3 > Problem8-130

8-130.

Implicitly integrate to find the function f(x), so that you can evaluate f(2). Knowing that f(1) = 2 will help you find the value of C, the constant of integration.


text:
# 11.1 Sequences and their notations  (Page 7/15)

 Page 7 / 15

$\left(\frac{12}{6}\right)!$

$\frac{12!}{6!}$

$665,280$

$\frac{100!}{99!}$

For the following exercises, write the first four terms of the sequence.

${a}_{n}=\frac{n!}{{n}^{\text{2}}}$

First four terms: $1,\frac{1}{2},\frac{2}{3},\frac{3}{2}$

${a}_{n}=\frac{3\cdot n!}{4\cdot n!}$

${a}_{n}=\frac{n!}{{n}^{2}-n-1}$

First four terms: $-1,2,\frac{6}{5},\frac{24}{11}$

${a}_{n}=\frac{100\cdot n}{n\left(n-1\right)!}$

## Graphical

For the following exercises, graph the first five terms of the indicated sequence

${a}_{n}=\frac{{\left(-1\right)}^{n}}{n}+n$

${a}_{n}=\frac{\left(n+1\right)!}{\left(n-1\right)!}$

For the following exercises, write an explicit formula for the sequence using the first five points shown on the graph.

${a}_{n}={2}^{n-2}$

For the following exercises, write a recursive formula for the sequence using the first five points shown on the graph.

## Technology

Follow these steps to evaluate a sequence defined recursively using a graphing calculator:

• On the home screen, key in the value for the initial term $\text{\hspace{0.17em}}{a}_{1}\text{\hspace{0.17em}}$ and press [ENTER] .
• Enter the recursive formula by keying in all numerical values given in the formula, along with the key strokes [2ND] ANS for the previous term $\text{\hspace{0.17em}}{a}_{n-1}.\text{\hspace{0.17em}}$ Press [ENTER] .
• Continue pressing [ENTER] to calculate the values for each successive term.

For the following exercises, use the steps above to find the indicated term or terms for the sequence.

Find the first five terms of the sequence Use the> Frac feature to give fractional results.

First five terms: $\frac{29}{37},\frac{152}{111},\frac{716}{333},\frac{3188}{999},\frac{13724}{2997}$

Find the 15 th term of the sequence

Find the first five terms of the sequence

First five terms: $2,3,5,17,65537$

Find the first ten terms of the sequence

Find the tenth term of the sequence

${a}_{10}=7,257,600$

Follow these steps to evaluate a finite sequence defined by an explicit formula. Using a TI-84, do the following.

• In the home screen, press [2ND] LIST .
• Scroll over to OPS and choose “seq(” from the dropdown list. Press [ENTER] .
• In the line headed “Expr:” type in the explicit formula, using the $\text{\hspace{0.17em}}\left[\text{X,T},\theta ,n\right]\text{\hspace{0.17em}}$ button for $\text{\hspace{0.17em}}n$
• In the line headed “Variable:” type in the variable used on the previous step.
• In the line headed “start:” key in the value of $\text{\hspace{0.17em}}n\text{\hspace{0.17em}}$ that begins the sequence.
• In the line headed “end:” key in the value of $\text{\hspace{0.17em}}n\text{\hspace{0.17em}}$ that ends the sequence.
• Press [ENTER] 3 times to return to the home screen. You will see the sequence syntax on the screen. Press [ENTER] to see the list of terms for the finite sequence defined. Use the right arrow key to scroll through the list of terms.

Using a TI-83, do the following.

• In the home screen, press [2ND] LIST .
• Scroll over to OPS and choose “seq(” from the dropdown list. Press [ENTER] .
• Enter the items in the order “Expr” , “Variable” , “start” , “end” separated by commas. See the instructions above for the description of each item.
• Press [ENTER] to see the list of terms for the finite sequence defined. Use the right arrow key to scroll through the list of terms.

For the following exercises, use the steps above to find the indicated terms for the sequence. Round to the nearest thousandth when necessary.

List the first five terms of the sequence ${a}_{n}=-\frac{28}{9}n+\frac{5}{3}.$

List the first six terms of the sequence

First six terms: $0.042,0.146,0.875,2.385,4.708$

List the first five terms of the sequence ${a}_{n}=\frac{15n\cdot {\left(-2\right)}^{n-1}}{47}$

List the first four terms of the sequence ${a}_{n}={5.7}^{n}+0.275\left(n-1\right)!$

First four terms: $5.975,32.765,185.743,1057.25,6023.521$

List the first six terms of the sequence ${a}_{n}=\frac{n!}{n}.$

## Extensions

Consider the sequence defined by ${a}_{n}=-6-8n.$ Is ${a}_{n}=-421$ a term in the sequence? Verify the result.

If $\text{\hspace{0.17em}}{a}_{n}=-421\text{\hspace{0.17em}}$ is a term in the sequence, then solving the equation $-421=-6-8n$ for $n$ will yield a non-negative integer. However, if $\text{\hspace{0.17em}}-421=-6-8n,\text{\hspace{0.17em}}$ then $n=51.875$ so ${a}_{n}=-421$ is not a term in the sequence.

What term in the sequence ${a}_{n}=\frac{{n}^{2}+4n+4}{2\left(n+2\right)}$ has the value $41?$ Verify the result.

Find a recursive formula for the sequence ( Hint : find a pattern for $\text{\hspace{0.17em}}{a}_{n}\text{\hspace{0.17em}}$ based on the first two terms.)

${a}_{1}=1,{a}_{2}=0,{a}_{n}={a}_{n-1}-{a}_{n-2}$

Calculate the first eight terms of the sequences ${a}_{n}=\frac{\left(n+2\right)!}{\left(n-1\right)!}$ and ${b}_{n}={n}^{3}+3{n}^{2}+2n,$ and then make a conjecture about the relationship between these two sequences.

Prove the conjecture made in the preceding exercise.

$\frac{\left(n+2\right)!}{\left(n-1\right)!}=\frac{\left(n+2\right)·\left(n+1\right)·\left(n\right)·\left(n-1\right)·...·3·2·1}{\left(n-1\right)·...·3·2·1}=n\left(n+1\right)\left(n+2\right)={n}^{3}+3{n}^{2}+2n$

preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
can nanotechnology change the direction of the face of the world
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
how did you get the value of 2000N.What calculations are needed to arrive at it
A hedge is contrusted to be in the shape of hyperbola near a fountain at the center of yard.the hedge will follow the asymptotes y=x and y=-x and closest distance near the distance to the centre fountain at 5 yards find the eqution of the hyperbola
A doctor prescribes 125 milligrams of a therapeutic drug that decays by about 30% each hour. To the nearest hour, what is the half-life of the drug?
Find the domain of the function in interval or inequality notation f(x)=4-9x+3x^2
hello
Outside temperatures over the course of a day can be modeled as a sinusoidal function. Suppose the high temperature of ?105°F??105°F? occurs at 5PM and the average temperature for the day is ?85°F.??85°F.? Find the temperature, to the nearest degree, at 9AM.
if you have the amplitude and the period and the phase shift ho would you know where to start and where to end?
rotation by 80 of (x^2/9)-(y^2/16)=1
thanks the domain is good but a i would like to get some other examples of how to find the range of a function
what is the standard form if the focus is at (0,2) ?
a²=4
hil
hi
A bridge is to be built in the shape of a semi-elliptical arch and is to have a span of 120 feet. The height of the arch at a distance of 40 feet from the center is to be 8 feet. Find the height of the arch at its center