Research And Realization Of CT Multi-axis Motion Control System

With the development of CT technology,the requirements for the performance of CT machines are getting higher and higher.CT machines require CT scanning beds and CT rotary scanning frames to achieve high-precision and high-speed multi-axis motion control.At present,several schemes based on single-axis motion or PLC/MCU to realize multi-axis motion control of CT scanning bed and CT rotary scanning frame can no longer meet the needs of CT motion control.This design uses the FPGA core board as the main control unit to design a CT multi-axis motion controller based on CT scanning bed path planning with high control accuracy and fast running speed.The main research contents of this paper are as follows:First,the functional requirements and performance indicators of CT multi-axis motion control system are clarified.According to the system requirements and performance indicators,the CT multi-axis motion control system scheme design is carried out.Firstly,the scheme of CT motion control system in China is compared,and the shortcomings are pointed out,and on this basis,the scheme of using FPGA core board as the main control unit to realize multi-axis motion control of CT is proposed.Second,the hardware design of the CT multi-axis motion control system was carried out.Select key components FPGA core board,servo driver,servo motor and encoder.According to the functional modules required by CT multi-axis motion control system,the FPGA peripheral circuit and its interface circuit were designed,and the PCB design was completed on the PCB editor.Then,the software design scheme of CT multi-axis motion system is expounded.Using the top-down design idea,each functional module is divided from the top-level module downwards,including RS485 communication logic design,encoder feedback module design,pulse output module design,and I/O input and output module,and the principle of each functional module is elaborated and designed.Third,the CT scan bed path planning algorithm was studied.A CT scan bed path planning algorithm based on improved artificial potential field algorithm is proposed.Firstly,the limitations of the traditional artificial potential field algorithm are analyzed,and then the problem of unreachable target in the traditional artificial potential field algorithm is solved by optimizing the gravitational function and repulsion function,and the local optimal solution problem is solved by introducing the virtual scanning bed position.Finally,simulation experiments are carried out in matlab to prove the feasibility and effectiveness of the algorithm in CT multi-axis motion control system.Finally,the CT multi-axis motion control system verification platform is built,and the basic circuit,communication reliability,servo control test and analysis and motion control system function test and analysis are carried out,and the experimental results show that the CT multi-axis motion control system studied in this topic meets the functional requirements,can achieve accurate scanning of special parts,reduce the dose of CT tube pay-off,and reduce the damage of radiation to the human body.