Design Of Four-axis Servo Drive System Based On ARM And FPGA

With the development of intelligent manufacturing,the motion control system plays an increasingly important role in the production of the national.At present,most of the multi-axis motion control systems such as CNC systems and robot systems still use a motion controller and multiple servo driver for control schemes.This traditional scheme has the disadvantages of large floor space and low integration.At the same time,many motion control systems need to operate in industrial scenes where motor parameters change and external disturbances continue.The traditional PID control method is sensitive to motor parameters and it is difficult to meet the requirements under complex conditions.Based on the above background,this paper proposes a four-axis servo system based on FPGA and ARM,and designs a four-axis current loop based on FPGA,and studies the speed loop,position loop control algorithm and servo system software and hardware architecture.In the servo drive control system,the control scheme of the three-ring routing of the position loop,the speed loop and the current loop is generally used to realize the feedback control of the position,speed and current of the permanent magnet synchronous motor.This control structure determines that the calculation speed of the inner loop restricts the calculation speed of the entire servo system.Only by ensuring that the calculation cycle of the current loop is short and the bandwidth of the current loop is large,a high-performance servo system can be designed;Speed control and position control are also the two most commonly used control modes in industrial control.High-performance speed loops and position loops are prerequisites for ensuring fast tracking of rotor speeds and precise positioning of servo systems.This paper focuses on improving the three-loop control performance of the servo system,proposes the hardware implementation of the current loop,and improves the speed loop and position loop control algorithm to design a high-performance multi-axis servo control system.Firstly,the mathematical model of permanent magnet synchronous motor is built,the current loop control model is established,the factors limiting the bandwidth of current loop are analyzed,and the improvement scheme of current loop bandwidth is proposed.The core module and auxiliary module of current loop based on FPGA are built.The key algorithm is compensated,and the module is optimized from the occupied resources and computing speed.At the same time,in order to realize the control of the four-axis permanent magnet synchronous motor,a four-axis current loop planning and scheduling scheme is proposed.Then,the requirements of multi-axis servo control system are analyzed,the ADRC technology is proposed,and the mathematical model of ADRC is analyzed.The ADRC algorithm is applied to the control of servo system speed loop and position loop.Because the ADRC algorithm has strong disturbance observation and disturbance compensation ability,the above design scheme is of great significance for improving the anti-interference ability of the servo system and improving the position loop and speed loop control performance of the servo system.Finally,based on the four-axis current loop scheme of FPGA,combined with the speed loop and position loop technology based on ADRC,a high-performance four-axis servo driver with independent intellectual property rights is designed.The Simulink simulation platform is built to simulate the ADRC algorithm and re-verify.The superiority of the ADRC algorithm is established.The experimental test platform of the servo system is built to verify the practicability of the four-axis servo system designed in this paper.