Design Of Motor Driver Used In Digital X-ray Machine Based On DSP

In this thesis, some research and designing work for motor driver are presented which is used for Digital X-ray machine according to the Medical instruments standards of China. The following four parts are included in the main research contents:reasearch on brushless DC motor and matlab simluation;analyzing of driver parameter and designing of electric circuit;designing of main software module;testing with loads and analyzing of results.The analysis of the principle of a brushless DC motor, the establishing of the mathemati-cal model of a brushless DC motor and its control system by the formula derivation, the simulating of the system by means of Matlab simulation tools are presentsed in the first part of this thesis.Analysis of the hardware circuit of the Servo driver, Including the the design requirements of drive parameters, the design of the control circuit, the design of power drive circuit and the design of the power supply circuit, the Analysis of the design parameters and the electrical characteristics of the main chip of each module are presented in the second part of this thesis. By comparing the electrical characteristics of the selected chip and the design parameters,it can be seen that the design meets the design requirements of the drive parameters. Draw schematics and PCB by using Cadence software,delivery processing-party system to complete the patch.Programs of the main module of the drive are presented in the third part of this thesis. First of all, the PID regulation of speed loop,current loop,position loop is researched.Then PWM wave generation module, the Hall signal detection module, the speed adjustment module and position adjustment module are programmed, the drive speed regulation and position adjustment through combination of hardware and software are achieved.The overall test environment which is built based on the design of the PCB and laboratory instruments is presented in the fourth part of this thesis. The response curve of driver with load is tested, including the current loop response curve, the speed loop response curve and the position loop response curve. By comparing a given curve and the actual response curve it can be seen the drive we designed has smaller static error, faster response speed. By comparing the accuracy of speed loop and position loop,it can be seen that the drive meets the system requirements, at the end,the requirement parameters of the drive and tesed results are listed which confirmed the drive parameters meet system design requirements. The speed loop accuracy range less than±1rpm.the position accuracy less than1Count. Through the entire test.lt can be seen that we complete speed loop and position loop.The speed accuracy and positional accuracy meet the requirements of the system design.