Design of the Position Controller for the Leaves of MLC Based on Cross-Coupled Control

According to requirements of the leaves position precision control of multi-leaf collimator (MLC) in the process of radiotherapy, the structure and working principle of the multi-leaf collimator of conformal radiation therapy apparatus was described. Firstly, the position controller of single leaf has been established, and then t fractional order Anti-windup controller was used to ensure the position accuracy of the MLC leaves and meet the requirements of conformal therapy. Finally, the position-loop cross-coupled controller is proposed to reduce the position error. The experimental results show that this method can meet the needs of the control precision of the leaves’ position of the multi-leaf collimator.