Modelling and control of a five‐degrees‐of‐freedom pneumatically actuated magnetic resonance‐compatible robot

摘要

BACKGROUND: Magnetic resonance imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. This paper introduces a pneumatically actuated surgical robotic system for prostatic interventions under MRI guidance. METHODS: A mechanical dynamics model was established using the Lagrange method and simulated using MATLAB software. A pneumatic actuator model was built through the use of system identification, and stability analysis was proposed based on the Nyquist criterion. In addition, a proportional-integral-derivative controller was implemented on the robot for accurate position control. RESULTS: Simulation results showed that the steady-state error of a step response was 0.3 mm and the tracking error of a 1.0 Hz sinusoidal response was 1.5 mm. Experimental results showed that the insertion precision was 0.72 mm in the general laboratory environment. CONCLUSIONS: The results demonstrated that the robotic system with the designed controller was effective in both position control and trajectory tracking.