Extended state observer-based synergetic control for n-DOF robot manipulators using joint position measurements only

Abstract

This research work focuses on the need to provide a control scheme able to tolerate multiple robotic control challenges related to noisy measurements, unknown disturbances and uncertainties using the joint position measurements only. The proposed control scheme avails the advantages of integrating the Extended State Observer (ESO) with the synergetic control to operate n-DOF robot manipulators. The ESO is known as a powerful tool that can provide the online estimation of the uncertainties, nonlinearities and disturbances to be rejected or compensated by a feedback stabilizer. Correspondingly, implementing ESO in the control scheme makes it work with less knowledge of the system model dynamics and states. On the other hand, the synergetic control is a proper controller that can provide the desired tracking performance, but it has a high dependency on the system model which makes it sensitive to control parameters variation and operating conditions. Hence, combining both techniques in one scheme is a convenient approach to overcoming the shortcoming of each method. The proposed method is tested experimentally on the MICO 4-DOF Kinova robot and its performance is compared to the conventional synergetic control considering three case studies to validate its effectiveness.