Design And Implementation Of Micrometering Pump Control System Based On DSP

Micro-metering pumps have a wide range of applications in the factory processcontrol. With the continuous development of control technology and digital informationtechnology, factory automation technology increasingly updated continuously improve theaccuracy and stability requirements for micro-metering pumps. Domestic micro-meteringpumps relative to foreign invested little late to start micro-metering pump from thestructure and control behind foreign countries. Domestic micro-metering pump control cansometimes be difficult to meet the complex factory production process need improvementfrom the structure and control strategy, it has higher control accuracy and better stability.This paper makes research and improvement on the control system of meteringpumps from the control strategy, studies the algorithm and its hardware circuit andsoftware control metering pump closed-loop. The main subject of research:First, the introduction analysis of micro-metering pump system research anddevelopment related to the basic situation at home and abroad. from the perspective ofclosed-loop control analysis of the strengths and weaknesses of each of the fullclosed-loop and semi-closed loop. Because the micro-metering pump flow pulsationphenomenon is not conducive to the realization of the whole closed-loop feedback flow, sothis paper uses half closed-loop control scheme.Next described in detail the characteristicsof the stepper motor of a drive source of the micro-metering pump, the drive mode, and acontrol method.This paper chooses two phase hybrid stepping motor, because its modelhas nonlinear, lag, complexity, so this article core control strategy use fuzzy PIDclosed-loop control to realize the micro-metering pump.Secondly, in terms of hardware design, hardware circuit TMS320F2812controllerchips, external expansion data memory circuit, LCD12864show circuit, the key circuits,alarm circuits and peripheral modules.Software used CCS3.3integration developmentsoftware program, use SCI interface of DSP and PC communication. The system acceptsthe flow control signal from the PC to send, and through the flow controller into thenecessary stepping motor frequency values, use periodic PWM DSP module and PWM signal empties compared adjustable to stepper motor drive, so that the metering pumpoperation. Also DSP quadrature encoder interface measured stepper motor speed feedbackto the control system,the system calls the fuzzy PID control algorithm for closed-loopcontrol to achieve accurate measurement of the micro-metering pump flow.Softwaremainly includes the main program, the initialization program, LCD12864display program,encoder feedback, closed-loop control algorithm procedures,as well as the communicationinterrupt service routine.Finally, the system with the host computer via the RS-232interface communicationand human-computer interaction monitoring interface design using VC++6.0interactionand display of data between the PC and slave computer.