Multi-axis Servo Control Technology Based On Multi-processor System On Chip

The mechanical phased array antenna adopts spiral antenna as the radiation unit,and the directional radiation and beam control of microwave are realized by mechanically rotating the spiral antenna unit to achieve the predetermined radiation phase.The spiral antenna unit is connected with driving equipment such as motor,and the rotation of the spiral antenna unit is realized by driving the motor,so as to realize the control of the radiation phase of the radiation unit.Motor control system is an important part of mechanical phased array antenna.Its performance directly affects the phase shifting speed and positioning accuracy of spiral antenna element,and then affects the performance of mechanical phased array antenna.The permanent magnet synchronous motor eliminates the excitation device and does not need the excitation current.It has the advantages of high power factor,simple structure and small size,so it is suitable for the drive control of the spiral antenna unit.In view of the unreasonable hardware and software division of the traditional multi-axis servo drive,it is difficult to meet the high-performance multi-axis servo drive system.Based on the design idea of hardware and software collaboration,a multi-axis servo drive controller scheme based on MPSoC is proposed.In a single FPGA,the main processor,multi-channel motor drive control module,network communication and other functional modules are integrated to construct the on-chip system of multi-axis servo motor drive control;Each motor drive control module completes the position,speed and current closed-loop control of single axis servo motor through hardware and software collaboration.The scheme has the advantages of simple structure,strong real-time performance,fast response and strong scalability.In order to complete the speed and current closed-loop control of single-axis motor with hardware and software cooperation,the current vector control algorithm with high real-time performance and relatively single control algorithm is realized by pure hardware logic,while the speed closed-loop control algorithm with strong flexibility or randomness is realized by embedded slave processor software.The current loop servo control IP core is designed by Verilog HDL,including phase current acquisition and processing,coordinate transformation,PID controller,SVPWM,speed/position calculation and other functional modules.Functional simulation using Modelsim software verifies the correctness of the design.In Nios II,C language is used to realize data interaction with the main processor,speed closed loop control algorithm and parameter configuration.In order to verify the multi-axis servo drive controller scheme,a three-core processor on-chip system is constructed to realize the independent and synchronous drive control of two servo motors.The data interaction between the main processor and the slave processor is realized by the combination of on-chip shared memory and MUTEX core,and the solution of power-on-chip self-starting of the system on multiple processors is given.The experimental platform of servo motor is built,and the control performance of current loop and speed loop is studied.The closed-loop control of current loop and speed loop at 40 KHz and 10 KHz is realized.The results show that it has good current dynamic response,but the overshoot is large.Under the given speed of 400r/min,1000r/min and1600r/min,the dynamic response time is 10.8ms,17.3ms and 24 ms respectively,and the steady state error is 2.05%,1.13% and 0.9% respectively.When the trapezoidal velocity profile is running,the velocity response is fast,no obvious overshoot occurs,and the steady-state error is≤0.63%.The parallel and synchronous control of two-axis motor is realized,and each motor has the characteristics of fast speed following and small current loop delay,which verifies the feasibility and effectiveness of this scheme.