The Research And Design Of Scanning Control System Based On DSP

Microwave infrared scanner is important portable equipment in meteorological Satellites. Scanning control system is the Electrical Control Actuator of the scanner, and its performance decides the imaging accuracy of the scanner and the task completion of the satellites. According to the high precision requirements of the microwave infrared scanner, the digital servo control system is designed based on TM320F2812 digital signal processor(DSP). The brushless DC motor is used in the system as its driven motor, and a double closed-loop control strategy of current-loop and speed loop is designed to implement a high inertia load drive control at a slow speed and balance the moment of inertia.The thesis mainly studies the scanning control system of its composition, control programme and the hardware and software design. It gives out a brief introduction of the brushless DC motor's working principles and athematical models. What's more, it analyses the causes of the torque rippleis and the method to reduce the torque ripples. In the system structural design,both drive motor and compensate motor are brushless DC motors,which are controlled by single DSP to form a dual motor control structure.For the rich resources of the DSP, the hardware is consisted of the DSP and some simple parts of peripheral interface circuit such as electrical power driving unit , sampling unit, serial communication and power supply module.When designing the software, the PWM control, signal acquisition, speed control and serial communication function are completed with C language programming. The double closed-loop control algorithm is fullfiled to meet the control performance requirements.At last, a debugging and Simulation software system is designed with LabVIEW to support the development of the scanning control system. A simulation model of brushless DC motor is also presented with Virtual Instrument of LabVIEW.The scanning control system has been debugged in the lab, the result shows that the hardware and software are reasonably designed, system works stably with a high control precision and meets the design performance indicators.