Fuzzy-PID Hybrid Control Strategy for Pneumatic Driven Surgical Robot

Robotic systems for Magnetic Resonance Imaging (MRI)guided interventional surgery are highly demanding on the magnetic compatibility of materials and driving methods. Pneumatic system is one of the most commonly used driving modes in MRI environment. Due to the nonlinearity, hysteresis and gas compressibility, it is a common problem for the position control of pneumatic system. Traditional PID algorithm is ease of use and with high position control accuracy, but it needs to use engineering method to set PID parameters, which is time consuming, and once the parameters are determined, it cannot be adjusted online, leading to poor adaptability. Fuzzy control algorithm does not depend on accurate mathematical model and has strong robustness, but it cannot eliminate the steady-state error. This paper proposes a fuzzy-PID hybrid control algorithm to adjust the PID parameters automatically, the simulation and experiment results show that the hybrid algorithm has the advantage of low overshoot, high accuracy and high adaptability.