Joint Low-level Compensation Control of Hydraulic Legged Robot Based On Force Impedance Characteristics

doi:10.3901/JME.2025.07.294

Abstract

Abstract: Force-based impedance control is one of the commonly used low-level control methods for the leg joints of hydraulic legged robots, and its principle is a dual-loop composite control, including force-controlled inner loop and impedance-controlled outer loop, and existing related studies are conducted for the force-controlled inner loop. The output of the impedance outer loop is used as the input of the force-control inner loop, and if the characteristics of the impedance outer loop can be compensated, combined with the relevant force-control inner loop control strategies, the performance of the low-level control of the joint will be further improved. Based on the above background, an impedance characteristic compensator is designed for the impedance-controlled outer loop, which takes into account the strong nonlinearity, time-varying parameter and load variability of the force-controlled inner loop, and changes the parameters of the outer-loop impedance characteristics from constant parameters to time-varying adaptive parameters to assist in improving the overall impedance control performance. The experimental results show that the controller can provide the basis for the control of the whole hydraulic legged robot based on the accuracy of force-based impedance control and has good adaptability to multiple working conditions.

Key words: legged robot, force-based impedance control, joint low-level control, impedance characteristics compensator

CLC Number:

TH137

YU Bin, HE Xiaolong, WANG Yuan, SHE Jinbo, BA Kaixian. Joint Low-level Compensation Control of Hydraulic Legged Robot Based On Force Impedance Characteristics[J]. Journal of Mechanical Engineering, 2025, 61(7): 294-300.

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