Active compliance control method for hydraulic drive unit of legged robot

Abstract

The invention relates to an active flexible control method for a hydraulic drive unit of a foot-type robot. A method for reducing the displacement of a valve core of a servo valve is adopted, so as to reduce the output flow and furthermore the damp control effect is achieved. A method of combining rigidity feedback control and load feedforward control is adopted to achieve high-precision rigidity control of the hydraulic drive unit; the damp control of the hydraulic drive unit is combined with the high-precision rigidity control of the hydraulic drive unit to achieve active flexible control of the hydraulic drive unit of the foot-type robot. The method has the following advantages that the active flexible control can be achieved by the control method, the adverse effect on the robot foot-state control due to the instantaneous stall of the hydraulic drive unit of each joint hydraulic drive unit caused by instantaneous power loss of the foot can be avoided and the high-precision rigidity control can be achieved under different load conditions.

Description

technical field [0001] The invention relates to the field of legged robot control, in particular to an active compliance control method for a hydraulic drive unit of a legged robot. Background technique [0002] The high-performance quadruped bionic robot with legged organisms as the bionic object has military and civilian potential in complex environments, and has become a hot spot in the field of robotics research. The hydraulically driven high-performance quadruped bionic robot BigDog successfully developed by Boston Company is in the forefront of the world with its superior motion performance. Due to the difficulty of controlling the drive unit, although the country is actively developing, there is still a big gap between the motion performance of the sample and the American BigDog. [0003] The nonlinearity of the hydraulic drive unit of the hydraulically driven legged robot and the complexity of adapting to the environment have increased the difficulty of controlling ...

AI Technical Summary

Problems solved by technology

When applying the traditional active compliance control method, due to the inherent characteristics of the hydraulic drive unit, its hydraulic stiffness is not infinite, and the external load force interference will cause position deviation of the position system itself, and this deviation will affect the stiffness control of the traditional active compliance control method Therefore, the system stiffness obtained by connecting the hydraulic stiffness and the target stiffness in series will deviate from the expected system stiffness due to the interference of the external load force, making it difficult to achieve high-precision stiffness control, and the impact resistance of the robot will also decrease

Excessive impact not only cannot make the robot walk stably, but also will cause irreparable damage to the previously sensitive control components of the robot body.

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