Double-closed-loop control method for five-freedom-degree hybrid robot

Abstract

The invention discloses a double-closed-loop control method for a five-freedom-degree hybrid robot. The double-closed-loop control method comprises the steps that an actual corner of the axis of a first revolute pair and an actual corner of the axis of a fourth revolute pair are detected through a first circular grating and a second circular grating in real time; the movement distance of a driven length adjusting device in the direction of a moving pair is detected through a linear grating in real time; the actual corner information and the actual rod length information are converted into actual corners for driving three servo motors through the algorithm, the actual corners are compared with the instruction value and converted into speed instructions through PID adjustment, and then position loop feedback control is achieved; and actual corners of three servo motor shafts are detected through absolute type angle encoders of the servo motors in real time and are subjected to differential processing to obtain the actual rotation speeds of the servo motors, and the actual rotation speeds are compared with the corresponding speed instructions, so that speed loop feedback control over the servo motors is achieved through PI adjustment. According to the double-closed-loop control method for the five-freedom-degree hybrid robot, rod length errors caused by lead screw transmission errors, thermal elongation and axial elastic deformation of a driving length adjusting device can be online compensated in real time.

Description

technical field [0001] The invention relates to a double-closed-loop control method for a robot, in particular to a double-closed-loop control method for a five-degree-of-freedom hybrid robot. Background technique [0002] Industrial robots generally adopt a semi-closed-loop control strategy, that is, the encoder is used to detect the actual rotation angle of the servo motor of each joint to form a semi-closed-loop control of position and speed. This control strategy is easy to debug and maintain, and has good stability, and has been widely used. However, the semi-closed-loop control cannot compensate the transmission error of the mechanical system and the pose error of the end effector caused by the elastic deformation of the components. If the position and orientation information of the output components of the robot mechanism can be directly detected, full-closed-loop feedback control can be implemented, which in turn helps to improve the motion accuracy of the robot end...

AI Technical Summary

Problems solved by technology

This method must go through two steps of calculation, the calculation time is long, and it is difficult to implement at the servo update rate

In addition, the circular grating installed on the Hooke hinge where the driven length adjustment device is connected to the frame has poor openness and is inconvenient for maintenance and replacement

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