A feedforward compensation approach for cable-driven musculoskeletal systems

摘要

This paper presents a feedforward compensation approach for musculoskeletal systems (MSs). Compared withtraditional rigid robots, human arms have the advantages of flexibility and safety in operation in unstructuredenvironments. However, the influence of external unknown disturbances, inner friction effects, and dynamic uncertaintiesof the MS makes it difficult to model and practically apply. In order to reduce the inner friction effectsof the hardware platform and the over-relaxation/tension of the cable-pull drive, a feedforward friction compensationmethod for the cable-pulled artificial muscle unit is proposed. The method analyzes the friction causes ofthe hardware structure and establishes a mapping network relationship between the joint variables and the muscleforce error in the muscle space. The experimental results show that the method can effectively improve the controlaccuracy and reduce the artificial muscle over-relaxation/tension instability.