Purpose This paper aims to introduce a six-degree-of-freedom cable-driven parallel robot specifically designed for active rehabilitation training at the intermediate and advanced levels. This robot addresses the upper limb functional impairments and related nerve injuries in patients with moderate to severe rehabilitation stages caused by stroke. Design/methodology/approach The overall structure of the robot selects a fully constrained mechanism and uses seven cables for control to achieve 6 degrees of freedom in space. Based on the robot structure and the cable tension distribution model, a hybrid force control strategy that combines active loading control with redundant force compensation is designed. The outer loop of the overall control strategy adopts PI control to adjust the lateral force and vertical force, while the inner loop uses a hybrid force controller to ensure precise force application by each actuator. Findings The simulation and experimental results show that this controller can significantly improve the accuracy of the system, ensure the balance during system unloading, the stability of the controller and the clinically acceptable force application accuracy. This proves the effectiveness of this method. Originality/value This paper proposes a dedicated cable-driven parallel mechanism integrated with a novel force control scheme that combines active loading and redundant force compensation. The approach is validated to significantly improve force control accuracy and stability during active rehabilitation training, addressing a key challenge in delivering precise haptic feedback for stroke recovery.
Zou et al. (Thu,) studied this question.