洁净机器人反应转矩观测与碰撞保护研究

Reactive Torque Observation and Collision Protection for Clean-room Manipulator

摘要:

提出一种基于反应转矩观测器的机器人碰撞保护方法；机器人的反应转矩由基于模型的干扰观测器估值得到,模型的建立包括电机系统转矩模型与机器人系统动力学模型两部分；由于洁净机器人特殊的构型及关节耦合关系,机器人的动力学建模被大大简化,同时对简化后的模型采用最小二乘法对惯性参数和摩擦参数进行辨识,提高了模型的精度；根据永磁同步电机的转矩模型与机器人动力学模型,可以得到基于电机电流的机器人关节转矩；机器人与外界环境接触时,关节转矩的增加量即为反应转矩；通过设计反应转矩观测器并采用力/位混合控制结构,实现基于电流的机器人主动柔顺控制功能,并在洁净机器人进行碰撞保护实验,实际运行结果验证了该方法的有效性。

Abstract:

An approach of robot collision protection based on reactive torque observation is presented. Reactive torque is estimated by the disturbance observer based on the model of the system, which including motor torque model and robot dynamic model. Because of the special structure and joint coupling relationship of clean-room robot, the dynamics of robot is greatly simplified, and simplified model is identified by the least squares method which improved the precision of the model. According to the torque of permanent magnet synchronous motor and dynamic of the robot, joint torque based on motor current can be getted. When robot contact with the external environment, the increasion of the joint torque is the reaction torque, which is used to implement the active compliance control combined with disturbance observer and the force/position hybrid control. At last, collision protection experiment is carried out on the clean-room robot, and the experimental results verify the effectiveness of the proposed method. 