Intelligent and classic Control of Rehabilitation Robot with Robust PID and Fuzzy Methods

Rehabilitation of patients with neurological and spinal cord injuries is conducted to improve brain flexibility and patient performance. The performance of rehabilitation robots requires high standards of safety and reliability due to their direct interaction with humans during therapeutic motions. One of the simplest robot arms is a Two degrees of freedom Robot Manipulator that its function is considered as the basis for the performance of other arms. Due to the nonlinear dynamics, the control of two degree of freedom arm face challenges. Due to its simplicity and low cost, a robust PID controller is used first. Next, the Mamdani and Sugeno fuzzy controllers are designed which include two inputs, namely error and error derivative, and torque output. Finally, the hybrid fuzzy controller is designed as the first joint of the robot using robust PID control, and the second joint using the Mamdani fuzzy control. Comparison of control methods shows that the fuzzy Momdani fuzzy controller at both axes provides the most limited torque for the joint engines. The most accuracy of working point is the fuzzy hybrid control. Sugeno control shows the maximum speed and torque.