Position Control of a DC Servo Multi-motor for Lower-Limb Exoskeletons

The angular position control of DC servo multi-motor using PID control has been proposed. The PID controller tuning is applied to the Ziegler-Nichols (ZN) method. The angular position control of the DC motor is built in the mixed (cascade) system consisting of six electric motors to drive the joint movement of the lower-limb exoskeleton (hip, knees, and ankle). The PID control design is implemented in the lower-limb exoskeleton and experimental setup and simulation are carried out to obtain proper proportional, integral, and derivative gains. Based on these gains, the PID controller gives a good response, without overshoot, fixed settling time, and is precise to get the desired angle.