基于DMFC的上肢外骨骼人—机协调控制系统

A DMFC-based Man-machine Coordinated Control System of Upper Limb Exoskeleton

摘要:

上肢外骨骼人—机协调控制系统中的一个关键问题是直角坐标系中的力信号转换成联合坐标系中力矩,该过程中奇点几乎一直存在；为了解决这个问题,提出了一种基于动态模型力控制器(dynamic model of force control,DMFC)的控制系统；利用阻尼最小二乘法处理负载,转矩补偿负载质量,避免了奇异性；在外骨骼的末端执行器处安装力传感器用于测量外骨骼和负载之间的力,通过相互作用力自动反映使用者的运动意图；实验结果表明,提出的控制系统具有非常好的稳定性和可负载性,当施加负载补偿时,不附加任何物体与附加5公斤对象的外骨骼末端执行器位置之间的稳态误差可减小至0.01 μm以下,完全满足起吊重物的上肢外骨骼需求。

Abstract:

The key problem of upper limb exoskeleton man- machine coordinated control system is Cartesian coordinate system signal convert into joint coordinate’s moment. Singular points almost exist in the processing all the time. A new control system based on dynamic model of force control is proposed in this paper. Damped least squares method is used to handle the load,and the load torque compensation quality,avoiding singularity. In addition,the sensor at the end of exoskeleton actuator is used to measure the force between the exoskeleton and the load,and the user's motion intent is reflected by interaction automatically. Experimental results show that the proposed control system has a very good stability and load resistance,when the load is applied,The steady-state error between the end position of the exoskeleton that not loading anything and the end position of the exoskeleton that not loading 5kg is reduced to 0.01 um,and this is quite meet the upper limb exoskeleton lifting heavy demand.