Dsp-based Dc Servo Position Control System

Because the brushless DC motor (BLDCM)has such advantages as less mass, long life-span, high torque and less magnetic linkage coupling, it has been applied more and more frequently in many industrial fields and people's daily life. To satisfy the demand of high accuracy on position control in permanent-magnet brushless DC servo system, this thesis mainly studied and developed a DSP based permanent-magnet brushless DC motor (PM-BLDCM) servo control system.First, the principle of BLDCM was presented, the mathematic model of which was whereafter made out. Then the emulation model was established by using MATLAB simulink tools. Among the emulation on different control algorithms, the algorithm of compound control using single neuron based PID and disturbance observer proposed by this thesis was more superior.DSP TMS320LF2407A of Texas Instrument had been employed to construct the hardware platform of BLDCM. A general scheme of the hardware platform was designed. Then the control circuit, the optoelectronic isolator circuit, the power amplifier circuit, the detection circuit of current and position were showed in detail.C was used to write the system programs by using the CCS simulink tools. The appropriate sampling frequency was selected according to the principle of selecting sampling period. Then the software for control was designed based on classic PID algorithm for current loop and velocity loop and on compound control algorithm using single neuron based PID and disturbance observer. Because the DSP selected was fixed-point CPU(TMS320LF2407A), Q format was selected for data notation which ensure the high-speed operation and accuracy of data.Finally, the experiments were made on a 100W PM-BLDCM with 3-couple poles by using the hardware platform designed above. The results showed that the algorithm was superior to classic PID algorithm, and also proved the reliability of this control system.