Vibration Suppression and Disturbance Rejection Based on Equivalent Mass and Stiffness Matrices

This paper proposes vibration suppression and disturbance rejection methods for multi-degrees-of-freedom (MDOF) manipulators with flexible joints in the workspace. The proposed methods utilize an equivalent mass matrix (EMM) and equivalent stiffness matrix (ESM) that represent the mass and stiffness in the workspace, respectively. In conventional methods, variations of EMM and ESM can degrade vibration suppression and disturbance rejection performances. Therefore, the proposed methods employ a workspace observer (WOB), resonance ratio control, and load-side workspace observer (LWOB). The WOB and resonance ratio control fix the EMM to constant values and realize stable vibration suppression. The LWOB improves ro-bustness by compensating for disturbances. The stability analyses reveal the parameter conditions. The simulation results show that the proposed methods suppress vibrations and disturbances in the workspace.