Design of Regeneration Energy Recovery Controller for Active Multi-axis Lower Limb Exoskeleton.

In this paper, a hardware and software design of regeneration energy recovery controller is proposed to solve the problem that the regeneration electric energy feedback from the motor winding to the DC bus will increase the voltage of the DC bus when the active multi-axis lower limb exoskeleton is braking and decelerating, and the motor is working in the regenerative braking mode. When the motor feedback energy causes the DC bus voltage to rise to the set threshold, enter the charging mode and use the bank capacitor to absorb the electric energy. When the DC bus voltage drops to the set threshold during the motor start or acceleration, it enters the discharge mode to release the electric energy in the bank capacitor. According to the hardware and software design, an equivalent circuit model is established for simulation analysis. The analysis results show that the regeneration energy recovery controller can effectively solve the problem of increasing the bus voltage when the active multi-axis lower limb exoskeleton stops.