Transformed Workspace Adaptive Mapping Based Master-Slave Operation Control for Hydraulic Manipulator

Abstract

The unstructured working environment poses a significant challenge in achieving autonomous operation of hydraulic manipulators, which has led to the widespread use of master-slave operation in practice. However, it is typical for the hydraulic manipulator and the master robot to exhibit different mechanical configurations (i.e., master-slave heterogeneity). This can result in excessive range differences and low similarity between the master and slave workspaces, leading to the hydraulic manipulator being unable to accurately reproduce the actual intentions of the operator. Furthermore, the nonlinear dynamics and end-load disturbance during operation significantly affect the control accuracy of the hydraulic manipulator. To address the aforementioned challenges in master-slave operation, this article proposes a novel control scheme based on transformed workspace adaptive mapping (TWAM). By reconstructing the transformed workspace, the similarity between the master and slave workspaces has been improved. Furthermore, the accurate utilization ratio (AUR) of the slave workspace has been expanded through an adaptive command mapping algorithm. Moreover, a model-based controller that takes into account nonlinear dynamics and the end-load disturbance is developed to ensure precise operation in various loaded states. Finally, a series of experiments are conducted, and the results have verified the practical applicability and effectiveness of the designed method.