基于阻抗模型的卧式康复机器人柔顺控制

Compliance control of horizontal rehabilitation robot based on impedance model

为满足脑卒中患者早期卧床康复需求,结合临床康复手法与人机工程学,设计了一款卧式康复机器人。该卧式康复机器人可以提供单腿屈髋屈膝运动、卧式步态运动、桥式运动等多种有效的康复动作。为确保训练的安全性以及改善在训练过程中由人机交互作用带来的舒适度和柔顺性差等问题,采用一种基于阻抗模型的柔顺控制方法。将人与机器人之间的交互视为一种虚拟的阻抗模型,即二阶质量-弹簧-阻尼模型,并基于该阻抗模型进行康复机器人的柔顺控制研究。该柔顺控制策略由外环阻抗控制器和内环PID控制器组成,外环的阻抗控制器通过将人机交互力作用在阻抗模型上,实现根据人体意图对运动轨迹进行改变,而内环的PID控制器主要实现对生成的期望轨迹进行稳定跟踪。通过实验证明了基于阻抗模型的卧式康复机器人柔顺控制的有效性。

To meet the needs of stroke patients in early bed rehabilitation,a horizontal rehabilitation robot is designed by combining clinical rehabilitation techniques and ergonomics.It can provide a variety of effective rehabilitation actions such as single-leg hip bending and knee bending,horizontal gait and bridge movement.In order to ensure the safety and improve the comfort and compliance problems caused by human-robot interaction during training,a compliance control method based on impedance model is adopted.The interaction between human and robot is regarded as a virtual impedance model,that is,the second-order mass-spring-damping model,and the compliance control of rehabilitation robot is studied based on this impedance model.The compliance control strategy consists of an outer loop impedance controller and an inner loop PID controller.The outer loop impedance controller changes the motion trajectory according to the human body's intention by applying human-robot interaction force on the impedance model,while the inner loop PID controller mainly realizes the stable tracking of the generated expected trajectory.And the effectiveness of compliance control of horizontal rehabilitation robot based on impedance model is proved by experiments.