Performance evaluation of the improved danger detection system for the safety of a handle type electric wheelchair

This paper describes the improvement and the performance evaluation of the hazard detection system to ensure the safety of a handle type electric wheelchair. We investigate the warning timing by Time-To-Incident (TTI) in consideration of the cognition, decision, and action time of elderly people and Japan Industrial Standards (JIS) of a handle type electric wheelchair. And then, the size of the target object (hazard object) to be detected and the measurement of the change in slope of road surface are studied. We carry out the performance evaluation of the improved system through the use of four types of the hazard detection rules. The items of the performance evaluation are TTI of the first time warning and the detection success rate of the true positive and the false negative. Furthermore, the evaluation of four types of the hazard detection rules by using the cost function is performed. The results provide the important knowledge for practical application of the hazard detection system.