Impedance control of the anthropomorphic arm文献综述
2020-05-05 16:47:40
In this paper only focused on Impedance control of the arm and planning to research robot arm with impedance control, and get knowledge about movements and all the positions of robot arm according to the information in the below. The 7-DoF DLR arms are especially designed for low weight. Consequently, the controllers must take account for the elasticity in the joints, which is caused mainly by the gears of the robot. For the controller design a flexible joint robot model is considered. Furthermore additional control problems arise due to the redundancy of the arm. A detailed description of the controllers developed for the DLR light-weight robots can be found here. Impedance control of the arm is most special interest. Notice that in particular the use of joint torque sensors allows the design of highly sensitive torque and impedance controllers. The controllers consist of an inner torque feedback loop and an outer impedance control loop which is based on the measurement of the motor side position. A physical interpretation of the inner torque feedback loop was given and used for a passivity based stability analysis of a Cartesian impedance controller. The purpose of the inner torque feedback loop is twofold. On the one hand, the torque feedback causes a decrease of the effective motor inertia for forces acting on the link side. Thereby it enhances the vibration damping effect of an additional outer control loop. On the other hand, it also diminishes the effects of motor side friction since the joint torque sensors are placed on the link side. In addition to the torque controller, an outer impedance control loop is used, which is based on the measurement of the motor position. This particular gravity compensation term allows compensating for the static effects of the link side gravity torques, but is based solely on the measurement of the motor side position. In addition to this stiffness and damping terms are implemented via a potential function and a positive definite damping matrix.