A Design Based On DSP Variable-speed Pump Water Supply System-Signal Collecting And Disposal Part

Research of water supply appears after centralization of our living environment and development of our living individuation. The research of speed-shifted-pump water supply is an important task. Some kind of water supply, controlled by Single Chip Micyoco(SCM) ,has low speed and laggard controlling method. Nowadays, DSP, with super-high speed ,low power loss and strong realtime quality, has been gradually substituting SCM to implement in intellective water supply. It makes motivity, economy and stability of speed-shifted-pump water supply improving gradually. This thesis just introduces the design of speed-shifted-pump water supply with TMS320LF2407 series of DSP as the core chip.TMS320LF2407 is a kind of digital signal processor with powerful function. This chip is one product of C2000 series, produced to apply in industry controlling region by American TI company ,whose market lot reaches 44 percent in the world. TMS320LF2407 has low power loss , high speed and strong controlling ability. This thesis analyzes the advantages of DSP in operating speed, integrating degree, specialization and stability. It also introduces CPU, memory and outside facility on-chip ofTMS320LF2407.The entire water supply includes two parts, which are signal collecting and disposal part and controlling part of TMS320LF2407 towards direct current motor without brush respectively. This system translates related autocontrol theory to realtime application arithmetic ,to form a stable and reliable minus feedback system with pre-channel and post-channel,in order to control the state conversion and speed adjusting of the direct current motor without brush. While the need of water is changing, the water piping can keep stable hydraulic pressure to meet the needs of constant water pressure.This thesis introduces the design scheme of the whole water supply, and designs the hardware circuit of the entire water supply. Then it introduces the characters of the hardware structure and design essential in detail, and put forward the argument of the scheme of signal collecting and disposal part. Based on this point, it present program design methods of every parts.Hardware circuit mainly includes signal collecting and disposal circuit and controlling circuit of TMS320LF2407 towards direct current motor without brush . The former includes pretreatment of signal(includes commutation, amplifying and so on) from pressure sensor and water-level sensor. It also includes A/D conversion of signals from the two sensors in A/D module embedded inside TMS320LF2407; the latter uses two event-managers ,EVA and EVB, which is inside the TMS320LF2407, to control one motor respectively: 6 routes of PWM signals controls 6 switches of power-shifted component respectively, and three captures, CAP1,CAP2.CAP3,can present the time information when phases of the motor shift and position information by capture interrupt. Besides, the hardware circuit also includes interface circuit between human and PC, which uses the chip of HD7279A,to apply in key-press input and LED display; memory expanding circuit ,uses IS61LV6416 chip, to offer data memory with 64K bites; R.S232 interface circuit, uses MAX3232 chip, to offer interface between PC and this system; JTAG interface circuit ,to realize downloading, simulating ,debugging and so on.The design thoughts of signal collecting and disposal part is very clear. The pressure sensor translates the water pressure signal to current signal, which will then be converted to voltage signal by current-voltage converter. The voltage signal is delivered into A/D module inside of TMS320LF2407 .After A/D conversion, the digital quantity will be sent into digital filter to wipe off interference. Then it will be processed scale transformation to be transformed to digital water pressure,as a parameter to control the three-phase direct current motor without brush.Water-level sensor, positioned in the pool, collects water level signal. After similar processing with water pressure signal, we obtain the digital water level signal. TMS320LF2407 checks whether the water level oversteps the maximum or the minimum of the pool, and gives an alarm respectively via hardware circuit. This thesis also processes series of programming design, including A/D converting program, digital filtering program, scale converting program, interface program and so on.As time and the writing level is limited, and some other reasons in addition, there are some disadvantages in this task. For example, this system hasn't completed the debugging of all of the program, and it can not satisfy the need of water in large scale. So it needs more effort in study and working in the future.