An Impedance Control Method of Robot Arm

Abstract

The invention provides a mechanical arm impedance control method, which combines the position-based impedance control method with the force-based impedance control method, the mechanical arm has a built-in joint position controller, and combines the admittance controller in the position-based impedance control method The control architecture of the inverse kinematics of the manipulator is replaced by the control architecture of the virtual impedance controller combined with the forward dynamics solver, and the impedance controller in the force-based impedance control system is replaced by a control loop, so that the pose error by Cartesian space The reference impedance F obtained by the reference impedance model imp Converge to the actual measured external force F s , and then output F through the closed-loop force controller FC . This method solves the problem of simultaneously ensuring control accuracy and stability when interacting with hard environments in the impedance control of the manipulator, and provides a new method for the motion control of industrial manipulators.

Description

technical field [0001] The invention belongs to the technical field of industrial machinery, and in particular relates to a method for controlling the impedance of a mechanical arm. Background technique [0002] There are two commonly used robot impedance control methods, one is force-based impedance control method, and the other is position-based impedance control method. The block diagrams of the two impedance control systems are as follows: figure 1 and figure 2 shown. [0003] With the force-based impedance control, the system has good stability when the manipulator interacts with the environment, but the impedance control effect depends on the accurate dynamic model of the manipulator. [0004] Employing position-based impedance control, the inner-loop position controller makes the method robust to friction and other unmodeled dynamics of the manipulator, thus freeing itself from the need for an accurate dynamics model. However, on the one hand, the impedance contr...

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Problems solved by technology

However, on the one hand, due to the slow response of the inner ring position, the impedance control accuracy is low; on the other hand, when the robot arm control system interacts with the hard environment, the stability is poor.

[0005] Therefore, neither of these two control architectures can solve the impedance control problem of the manipulator well.

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