Mechanical arm safety trajectory tracking control method based on sliding mode

Abstract

The invention relates to a mechanical arm safety trajectory tracking control method based on a sliding mode. The method comprises the following steps that 1, the angle, the angular speed and the input torque estimation information currently corresponding to each joint in the mechanical arm are obtained, so that the disturbance torque estimation value currently corresponding to each joint in the mechanical arm can be obtained through calculation; 2, a track scaling function is determined, track interpolation time of the mechanical arm is determined according to the track scaling function, and the actual tracking track of the mechanical arm is obtained through the track interpolation time of the mechanical arm; and 3, the expected joint angle, angular velocity and angular acceleration corresponding to the actual tracking trajectory are input into a sliding mode controller, trajectory tracking control is conducted on the mechanical arm through the sliding mode controller, and therefore high-precision trajectory tracking of the mechanical arm under the action of external disturbance is achieved. The position tracking precision can be improved, work task interruption caused by collision is avoided, and safety and reliability are achieved.

Description

technical field [0001] The invention relates to a control method, in particular to a sliding mode-based safe trajectory tracking control method for a mechanical arm. Background technique [0002] In recent years, human-computer interaction robots have been increasingly used in light industrial assembly, electronic information, and home services. In these fields of human-machine shared workspace, human-machine safety and work efficiency have become the most concerned. The problem. The challenge for robots is not only to detect collisions in real time and adopt corresponding safety control strategies, but also how to reduce the damage caused by collisions without interrupting the current work tasks. [0003] At present, the safety control methods of manipulators mainly include two methods: force control and impedance control. Force control mainly includes zero-force control and reflection control. Both of these algorithms can escape from the collision area at the moment of c...

AI Technical Summary

Problems solved by technology

Force control mainly includes zero-force control and reflection control. Both of these algorithms can escape from the collision area at the moment of collision, but they will deviate from the original motion trajectory, resulting in unnecessary interruption of work tasks, and the mechanical arm will escape from the collision area. During the process, secondary collisions with surrounding static obstacles may occur due to deviation from the off-line planned collision-free path

Compared with force control, impedance control establishes the relationship between force and position, so that the mechanical arm exhibits the required rigidity and damping to achieve a compliant function, and can return to the nominal path after the collision, but impedance control reduces the position control precision

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