Wearable Sensors Help Analyze Behaviors of Factory Workers
DSS Co Ltd, a Japanese firm that edits and processes digital maps based on survey data, started a service of recording the actions of factory workers for long hours and visualize them.
The tools used for collecting the data are (1) the "ankle sensor" to be attached to the leg of a worker for recording his or her movement, (2) the "milestone," which will be installed in various places in the plant to know how long workers stay there and (3) the "small video camera" to be put in the chest pocket of the worker to record his or her action.
The data of up to 30 workers can be collected at the same time. Data of three days and a behavior analysis report based on them cost about two million yen (approx US$20,857). Until Aug 20, 2009, DSS will offer a two-day data collection and rent software to analyze the data for ¥980,000 to up to five companies.
In general, camcorders are used to record the actions of factory workers. However, with this method, each worker has to be accompanied by a staffer carrying a video camera, costing time and money. DSS aims to cut labor costs by automation.
To collect the data, a digital map of the workplace is created. Then, the milestones are set at key locations such as work areas and storage spaces, and the ankle sensors are attached to workers. The rest is to let them work as usual.
Equipped with a gyro sensor and an acceleration sensor, the ankle sensor keeps track of the coordinates of the worker and records them in the embedded memory. This process causes the displacement of the coordinates. Therefore, the displacement is automatically adjusted when the ankle sensor passes in front of the milestone (within 2m).
The milestone records the time when a worker steps in the infrared beam and the time when he or she steps out of it. As a result, it is possible to calculate how long the worker stayed in the area.