基于导纳模型的体重支持系统恒力控制研究

Research on Constant Force Control of Weight Support System Based on Admittance Model

关键词:  康复机器人体重支持系统  导纳模型  双闭环  恒力控制

Key words:  Rehabilitation robot weight support system  Admittance model  Double closed loop  Constant force control

摘要:

为保证康复机器人可以在进行康复训练时提供持续稳定的支持力,提出一种基于导纳模型的双闭环控制算法,可以适应不同康复阶段,并能在发生突发情况时,减小对患者伤害。康复机器人使用拉力传感器实时监测其为患者提供的辅助支持力,通过判断力的变化自动调整到合适的康复阶段模式。康复前期所需支持力较大,但由于患者下肢力量不足,行走动作缓慢,支持力变化率较小；康复后期或发生跌倒等意外情况时,支持力变化率较大,康复机器人快速反应适应患者节奏,并在患者发生跌倒等情况时顺应患者重心趋势,避免与其发生对抗,避免造成二次伤害。通过实验数据分析可知,所设计的下肢康复机器人控制方案在康复各阶段都起到了良好的作用,同时提高了康复训练的安全性,可以满足患者康复训练需求。

Abstract:

In order to ensure that the rehabilitation robot can provide continuous and stable support during rehabilitation training, a double closed-loop control algorithm based on admittance model is proposed, which can adapt to different rehabilitation stages and reduce the harm to patients in case of emergency. The rehabilitation robot uses the tension sensor to monitor the auxiliary support it provides to patients in real time, and automatically adjusts to the appropriate rehabilitation stage mode through the change of judgment. In the early stage of rehabilitation, the support is great, but the patient"s lower limb strength is insufficient, and his walking action is slow, so the change rate of support is small. In the late stage of rehabilitation or in the event of an accident such as a fall, the change rate of support force is large, and the rehabilitation robot quickly responds to the patient"s rhythm, and conforms to the patient"s gravity center trend when the patient falls, so as to avoid confrontation and secondary injury. Through the analysis of experimental data, it can be seen that the designed control scheme of lower limb rehabilitation robot plays a good role in all stages of rehabilitation, and at the same time improves the safety of rehabilitation training, which can meet the needs of patients" rehabilitation training.