基于模煳PID调节的核磁兼容机器人气动控制技术.pdf

34 5 ROBOT Vol.34, No.5 2012 9 Sep., 2012 DOI 10.3724/SP.J.1218.2012.00531 PID 1 1 1 2 1. 300072 2. 300121 MRI – – PID PWM PID 0.79 mm MRI PID TP24 A 1002-0446(2012)-05-0531-08 Pneumatic Control Technology Based on Fuzzy PID for MRI Compatible Robots JIANG Shan1 FENG Wenhao1 YANG Zhiyong1 LIU Jun2 (1. School of Mechanical Engineering, Tianjin University, Tianjin 300072, China; 2. Department of Magnetic Resonance, Tianjin Union Medicine Center, Tianjin 300121, China) Abstract: Based on the analysis of the independently developed MRI-guided needle-penetrating robot, a pneumatic con- trol system is designed. The on/off valve-cylinder model, cylinder friction model and long transmission lines model are established. Then, a fuzzy PID (proportional-integral-derivative) controller is designed, and PWM (pulse width modulation) signal is decomposed linearly. Simulation and experimental results indicate that the controller is effective in both position control and trajectory tracking. The controller is implemented on the robot to verify the needle precision, and the results show that the error of needle penetration is 0.79 mm, which meets the accuracy requirement. Keywords: magnetic resonance imaging (MRI); surgical robot; pneumatic control system; fuzzy PID (proportional- integral-derivative) 1 Introduction SNR MRI