DEVELOPMENT RESEARCH OF A LOCOMOTIVE WALKING VEHICLE FOR PARAPLEGICS

为了开发能够在我们的生活空间中毫无困难地运送截瘫患者的机车车辆，提出了一种腿部机构步行椅的概念。从安全性、实用性和步行功能三方面考虑，提出了一种步行椅腿机构的结构。步行椅有三个在矢状面上运动的平面腿机构，每个机构具有相同的运动学尺寸，外部的两条腿在同一阶段被驱动。内侧腿在脚踝关节处有一个旋转关节，用于改变行走方向。每条腿主要由两个机构组成。一种是在平坦的水平地形上产生腿部运动的基本机构，另一种是调整台阶、楼梯、斜坡等腿部运动的运动调节机构。这两个机构的运动通过受电弓机构传递到脚上。对这些机构进行了空间综合。腿部机构上还安装了机构，用于在不平坦的地形上行走时被动稳定身体的姿态。在此基础上，研制出总高1179 mm、总质量136 kg的步行椅样机。样机的腿部机构已被证实具有足够的工作空间，可以在通常的楼梯上行走。该步行椅实现了以50步/分钟的速度在平坦的水平地形上稳定行走，在最大步长为20 mm的不平坦地形上实现了稳定行走。在考虑支腿机构间隙和弹性变形的情况下，对步行椅本体的运动进行了理论分析，为设计提供了依据。

In order to develop locomotive vehicles which can transport the paraplegic on it in our life space without difficulties, a concept of walking chair by means of leg mechanisms has been proposed. A structure of leg mechanisms for a walking chair has been presented with consideration of its safety, practical usefullness as well as walking functions. A walking chair has three planar leg mechanisms moving in the sagittal planes, each of which has kinematically the same dimensions and the outer two legs are driven in the same phase. The inner leg has a revolute joint at its ankle joint for changing walking direction. Each leg is mainly composed of two mechanisms. The one is the fundamental mechanism which generates the leg motion for flat horizontal terrain and the other is the motion-adjusting mechanism which adjusts the leg motion for steps, stairs, slopes and so on. The motions of these two mechanisms are transmitted to the foot by means of a pantograph mechanism. Dimensional syntheses of these mechanisms have been carried out. A mechanism is also installed to the leg mechanism for passively stabilizing the attitude of the body during walking on uneven terrain. Based on the results mentioned above, a prototype walking chair has been constructed, whose total height and total mass are 1179mm and 136kg, respectively. The leg mechanism of the prototype has been confirmed to have a working space adequate to walking on usual stairs. The walking chair has realized stable walking on flat horizontal terrain at 50 steps/min and it has realized stable walking on uneven terrain having steps whose maximum height is 20mm. The motion of the body of the walking chair has been also analyzed theoretically with consideration of backlashes and elastic deformations of the leg mechanism, which offers design material.