Research Of Limited Angle Brushless DC Torque Motor Control System Based On FPGA

Choose the limited angle brushless DC torque motor as the executive machine and select inductosyn as position sensor to compose a motor servo system. This system has many advantages, such as:powerful output, wide frequency band, minimal torque fluctuation, high track precision, small size and light weight. As a result of its high-performance, this system is very widely used in the scanning mechanism of space remote sensing camera, to drive in limited angle. Based on the research project "The key technique of space orientation, scanning motion control", this paper designs a limited angle brushless DC torque motor control system based on FPGA with the requirements of the actual project.Firstly, this paper systematically expounds the components and operating principles of the limited angle brushless DC torque motor. On this basis, the mathematical model is setted up. Moreover, this paper gets the transfer function of the motor. The operation principle of the introduction is discussed in detail, including the common single-phase excitation dual phase output amplitude discrimination mode and double phase excitation single-phase output phase mode.Then, this paper analyzes the control algorithm and speed detection scheme in the proposed System control scheme, uses the System Generator software to simulate the motor System, and then build a motor simulation model according to its mathematical model, controls the motor model by building controller model. It also gives detailed introduction of the composition principle of each module, and analyzes the double closed-loop PI control mode’s influence on motor control System performance, in order to provide reference of the PI regulator proportion parameters and integral parameter selection, multiplier output bit width influence on the system for FPGA design. According to the system design scheme, introduces the hardware circuit module of the system, develops the FPGA design of the controller, uses the VHDL language to realize function of PWM output module, PI regulator module, SPWM signal produce module, angle integration module, speed detection module, RS-422communication module.Finally, it performs debugging experiments to the system and analyzes the results. The result indicates that the motor control system has the functional requirements, it has angle measurement accuracy of±13.86", positioning accuracy of±13.86", and response time is less than2s. Steady uniform motion accuracy is less than6%and the RMS is less than2%. The motor control system has good dynamic and static performance.