Nonlinear disturbance attenuation control of hydraulic robotics

TL;DR

This paper introduces a nonlinear disturbance rejection control method for hydraulic robots that estimates disturbances without linearizing dynamics, enhancing robustness and tracking performance validated through extensive real-world experiments.

Contribution

The paper proposes a novel nonlinear disturbance attenuation control method using third-order filters and inverse dynamics, avoiding linearization of rigid body dynamics.

Findings

Demonstrates superior tracking performance over existing methods

Shows robustness under internal and external disturbances

Validated extensively on real hardware with various tasks

Abstract

This paper presents a novel nonlinear disturbance rejection control for hydraulic robots. This method requires two third-order filters as well as inverse dynamics in order to estimate the disturbances. All the parameters for the third-order filters are pre-defined. The proposed method is nonlinear, which does not require the linearization of the rigid body dynamics. The estimated disturbances are used by the nonlinear controller in order to achieve disturbance attenuation. The performance of the proposed approach is compared with existing approaches. Finally, the tracking performance and robustness of the proposed approach is validated extensively on real hardware by performing different tasks under either internal or both internal and external disturbances. The experimental results demonstrate the robustness and superior tracking performance of the proposed approach.