A Study on Speed Control for Assisting Unit of Wheeled Walking Frames

近年来，在老龄化社会中，人们对轮式步行器的期望越来越高。轮式步行器是老年人或残疾人康复时使用的辅助设备。轮式行走架有室内式和室外式两种。户外用的是拿着行李走路比较困难的人，或者经常用拐杖的人。医院或机构的室内式步行器是主要用于康复的高支撑性设备。两种传统的轮式行走支架在上下坡度行走时都存在弱点。针对目前轮式步行机存在的问题，采用广义内模控制(IMC)设计结构来解决目前轮式步行机存在的这些问题。为此，我们研制了轮式步行机助力单元的速度控制系统。内模控制器设计在工业控制技术中得到了广泛的应用。基于基于观测器的二自由度伺服系统的LQ控制的广义内模控制结构在轮式步行机的速度控制中的应用具有挑战性。该控制方法通过伺服补偿实现了良好的干扰解耦和轨迹跟踪性能。实验结果表明，带伺服补偿的广义内模控制对轮式步行机助力单元的速度控制是有效的。该方法的扰动解耦特性对上坡和下坡的影响尤为明显，对于需要轮式助行器的人来说，该辅助装置具有一定的实用价值。轮式行走将被老年人或残疾人使用，以独立生活。

In the aging society of recent years, the expectation for the wheeled walking frames increases. Wheeled walking frames are supporting equipments, to be used by elderly people or handicapped in rehabilitation. Wheeled walking frames have indoors type and outdoors type. The outdoor type uses the difficult person who walking with luggage or the person who is usually using the stick. The indoor type walking frames for hospital or institution is high supporting equipments for mostly rehabilitation. Both conventional wheeled walking frames have weakness in walking on upward / downward slope. People often need power assistance on upward, and need secure walking support without falling on downward.The purpose of this study is to solve these problems of current wheeled walking frames by using the generalized internal model control (IMC) design structure. Therefore, we develop a speed control for assisting unit of wheeled walking frames. The IMC design is widely used in industrial control technology. The control application to speed control of wheeled walking frames would be challenging by using the generalized IMC design structure with LQ control.The proposed method is based on a two-degree-of-freedom servo system using an observer-based stabilizing controller. The control method achieves good disturbance decoupling and good trajectory tracking performance with servo compensation. The experimental results showed that the generalized IMC with servo compensation was effective to speed control of the assisting unit for the wheeled walking frames. The disturbance decoupling property of the proposed method effects especially on going upward and downward slope.We believe that the assisting unit is helpful and useful for people who need the wheeled walking frames. The wheeled walking will be used by elderly or disable people in order to live independently.