Research For DC Speed Regulation Instrument Based On PWM

In recent years, the DC motor's structure and control mode have taken great changes. With the development of power electronics devices and power-control technology, the PWM mode using fully controlled power devices already becomesmainstream. At the same time, the digital signal processor appeared and it provided new method to the direct-current velocity modulation control. This control mode is very easy to realize based on DSP. It provided new change for the direct current motor control digitization. The thesis researches the digital control technique and fuzzy logical policy systemically, based on analyzing the working theory and math model for speed regulating system for DC motor.Firstly, In the paper, the development of DC motor control in our country and abroad is summarized first, and the control methods of DC motor as well as the Pulse Width Modulation of DC motor.The thesis is established in engineering application and specific request for speed regulating system and analyzes the working mode, condition and existent problems concretely. By researching the function and configurations of main circuit and control sections, a hardware design scheme is presented based on the TMS320F2407DSP for digital system.As a very important role for the accurate motion of DC motor, the control software adopting simultaneously the C and assemble language, the development is based on the CCS2000 integrated development. Corresponding software design and experiment research are carried out. In the section of the software implement methods, the analysis and the corresponding flow charts of every step, such as main program, generation of PWM control signal, A/D conversion, interrupt processing and so on.After introducing principle of fuzzy logic control (FLC), the thesis focus on researching the influence of input and output scaling factors of two dimensions Pi-type FLC. Then a parameter self-tuning scheme for Pi-type FLC is applied in the PWM speed regulation system for DC motor. Based on this controller, the thesis presents a suit of fuzzy logic rules which is suitable for PWM speed regulation for DC motor, and introduces the structure function block of fuzzy logic controller. It illuminates the theory and implement of fuzzy logic control in detail, and gets emulation results under different modes by simulation study of the MATLAB and SIMULINK. After analyzing dynamic performance concretely under fuzzy logic control, it is proved that the proposed scheme is capable of improving the dynamic response characteristic of PWM speed regulation for DC motor in effect, and suitable to the math model which is complex nonlinear.