Novel Acceleration Estimation for Improving Stability and Performance in Impedance Control

This article presents a novel approach to enhancing the stability and performance of impedance control in robotic systems through improved acceleration estimation. The focus is on Series Elastic Actuators (SEAs), which are vital for achieving precise force control and ensuring safe and efficient human-robot collaboration. Traditional cascade impedance control is limited by the passive nature of the system, particularly when rendering high stiffness values. To address these limitations, we introduce Elastic Structure Preserving (ESP) control, which retains the inherent elastic structure of the SEA while enabling high-performance impedance rendering. A key aspect of ESP is the accurate estimation of load-side acceleration, which is crucial for ensuring stability and maintaining control performance. To achieve this, we propose a new acceleration estimation technique that enhances impedance rendering. Experimental results demonstrate the effectiveness of the proposed method, which shows improved stability and precise impedance control. This approach offers a robust solution for advanced robotic applications requiring high stiffness and precise force control.