| With the fast development of computer technology and embedded microprocessor technology, the intelligent control technology is playing a more and more important role in satisfying people's demand of daily life and improving life quality. It is an important subject that the intelligent control system of constant pressure water supply system is being researched. The constant pressure water supply system with an digital signalprocessor(DSP) control core has an good performance------high speed, good real-time.compared with the Singlechip-controlled water supply system, it is more powerful in aspects of dynamic performance, economy and stability. This paper does some reseach,discuss and design on this DSP-controlled constant pressure water supply system.The mainly purpose of this system is constructing a stable and high reliable negative feedback system made up of DSP control core, forward-channel and backward-channel, which can control the states transition and speed adjustment of brushless dc motor. While the need of water is changing, the water supply system can keep stable hydraulic pressure.The system selects the popular digital signal processor DSP------TMS320LF2407as the control center. This chip is one of the c2000 products apt to industry control produced by American TI company. It has low power consumption, high executive speed, strong real-time control ability. This paper compares DSP with MCU, analyses the advantage of the DSP such as operation speed, integration level and stability, introduces the CPU ,memory structure and internal peripheral of TMS320LF2407 in detail, and discuss the strcture characteristics completely adapt to motor control.This paper introduces the primary principle of the PWM control of three-phase brushless dc motor and decide to use the double closed - loop system after deep research, puts forward a whole design idea of control realization. It consists basic circuit, signal collection circuit of three-phase brushless dc motor, executive mechanism, interface circuit of DSP and power supply circuit. Among them, the signal collection circuit of three-phase brushless dc motor mainly consists of hall sensors, resistance sensor and pre-processing circuit, can collect two important signals of three-phase brushless dc motor, then amplify and shape them. The executive mechanism is the part of circuits which measure and calculate the input signals and adjust the rotational speed.Based on the reseach of control scheme, this paper introduces the control scheme in detail,makes the double closed - loop PID control plan, control algorithm and hardware implementation on the DSP. The software use the modular design method, includes init module, starting module, gathering module, control module and man-machine interfaces module,etc. The paper gives the system program flow chart and module chart, and present the design thought and program list respectively. The paper alse explain the program difficulty, and introduce the problems that may occur and the corresponding way.Currently, DSP technology develops vary repidly, has been applied to many fields, such as information processing,communications and industrial control. The design and realization of this system makes a positive exploration for the farther decline of power system operating costs and reliability of water supply control system.For the limited level,time and some other objective reasons, there are still many lack in this topic. The system has not completed all the field debugging, and put other algorithms (such as fuzzy algorithm,neural network algorithm, etc.) into the reseach of constant pressure water supply system. Further research should be proceeded in the further work and study.
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