Virtual Decomposition Control of a Multi-degree-of-freedom Rehabilitation Exoskeleton Robotic Arm

In order to meet the needs of rehabilitation training for stroke patients, the rehabilitation exoskeleton manipulator arm needs to have multiple degrees of freedom. The rehabilitation exoskeleton manipulator arm used in this project has 5 degrees of freedom.Excluding the relatively independent wrist joints, the remaining 4 degrees of freedom of the manipulator arm still need to be controlled with high precision to ensure the safety, comfort and rehabilitation effect of patients. The multi-degree-of-freedom tandem manipulator arm has a high degree of nonlinearity, which increases the complexity of its modeling and control. Using the virtual decomposition control theory, the complex system is decomposed into several simple subsystems for analysis and control, and then all the subsystem controllers are assembled into a system virtual decomposition controller, which reduces the complexity of dynamic modeling, greatly reduces control and calculation and is convenient to improve the responsiveness of the system. Simulink and ADAMS are used to carry out joint control simulation and physical experiment of the manipulator, which is compared with the PID control method which adopts fixed gravity compensation. The results show that for highly nonlinear systems, the control effect of the virtual decomposition theory is better than that of the PID method.