抄録
In order to extend the area of activity for wheelchair users, the vehicles modified with a wheelchair transporting apparatus (WTA) has been noticed recently. The WTA allows users to travel for long distance. However, this system has been described as uncomfortable because the wheelchair is rigidly secured on the vehicle floor and the vibration of the floor is directly transmitted to passenger. The objectives of the present study are to investigate the vibration in the WTA and to clarify the design problems.
First, in order to measure the vibration of the WTA, the driving experiment using an automobile was performed at 3 levels of 30, 50 and 70 km/h. The vibration in the front-back and vertical directions on the Passenger-Wheelchair-Floor system was measured by acceleration sensors. The measurement points were 5 points on the passenger's body, 3 points on the wheelchair, and 2 points on thefl oor. As a result, the input vibration of the floor between 1 and 10 Hz was found to generate resonance. In addition, the equipment used to secure the wheelchair was found to increase the acceleration of the floor vibration. Therefore, the input vibration between 1 and 10 Hz is revealed as a factor that causes discomfort in the WTA.
Next, as design problems, necessity of reducing acceleration between 1 and 10 Hz was pointed out. In order to solve this problem, a method to clarify the characteristics of shock-absorbing equipment was proposed.
