Equivalent Disturbance Compensator and Friction Compensation for Back-Forward Drivability Improvement

This paper focuses on single inertialization on the load-side parameter of two-inertia system and employs the equivalent disturbance compensator (EDC). Conventional EDC is designed in case of the plant system without friction; thus, the back-forward drivability control using the EDC is affected by friction. In this paper, we propose the back-forward drivability control using EDC and DOB for single inertialization of two-inertia system. DOB is used to compensate the friction and the EDC is applied to not only improve the back-forward drivability, but also suppress the vibration on load-side output. This proposal consists of basic actuator and force sensor and it is available to general robot actuator that uses current sensor, motor encoder, and force sensor. The effectiveness of proposed back-forward drivability control is verified through the numerical simulation.