The Study Of Control Strategy Based On Single-Point Injection

With the use of diesel engine is expanding in diesel engine, people put forward higher request for diesel engine control performance because the structure of diesel engine is increasingly perfect. Meanwhile the energy problem gradually become important in influencing international politics, economy, development pattern. Recent years electrically control of monomer diesel engines fuel system has increasingly influence in domestic. Electric monomer pump adopts current discharge valve which can work high-speed and causes it become a major with time control characteristics, that make it won the ideal control performance. Using electric monomer pump fuel system can not only realize ideal diesel engine performance and fuel economy index, also can achieve on emissions effect improvement. Several cylinders sharing a injector called single-point injection. The single injection system also says the central fuel injection, it has three parts:oil-supplied part, gas supply part and controlling part. The electric fuel pump set up fuel box inside, the oil through fuel filter to central thrower with low pressure. This paper discusses high-speed solenoid valve control strategy and USB data acquisition card used for the pressure and electromagnetic valve control current of single-point injection.Monomer pump is an injection pressure device used to produce injector. The key of the electric monomer pump is to realize the high-speed solenoid valve pump inside. The core component of the electronic-controlled monomer pump, it must be able to work under high pressure achieve rapid (switch lower speed 1 millisecond), high frequency (each switch frequency 25 times more) execute actions, and at the same time to ensure reliable sealing effectiveness. High-speed solenoid valves controlled by modulation current, through changing the current realizing to control high-speed solenoid valves to steep current signal edge to make injection quantity has high repeatability. In addition, it should be used on the premise of the solenoid minimum power loss. In order to make the pump injection characteristics meet different operating conditions, the start of entire circuit and current control should be very precise.This article analyse the points of electromagnetic valve opens and cut-off, change drive time by exerting different driving voltage. By using icon and form,it shows that in the same electromagnetic valve high-pressure drive, close the high-pressure timely when electromagnetic valve current curve reach inflection point will greatly reduce the electromagnetic valve current banked steeply rising. And the lower of the electromagnetic valve current at Low-end MOS tube shutoff moments, the shorter of the Electromagnetic valve current in disappear stage spending time.We obtain ideal control performance through studying the solenoid valve opens and cut-off. In order to keep real-time monitoring on the pressure produced by monomer pump,This paper designs a high-speed USB data acquisition card based on a single injection meter. High speed data acquisition system is application equipment which has the strict request on the sampling times, transmission time and acquisition of data acquisition. The data acquisition system based on the USB interface is widely used in high-speed data acquisition system. This acquisition system is characterized by sampling interval controllable, transmission speed and high precision.The high-speed data acquisition system is based on USB2.0 interface for the collection and display pressure waveform real-time. The data acquisition system based on the universal USB2.0 interface, combined MAX232 by using the Cypress company CY7C68013A chips. The hardware of system mainly consist of signal regulate circuit, C8051F060 USB2.0 chip microcontroller, Cy7c68013a, serial ports chip MAX232, external memory chip M68AW127B, external EEPROM24LC256. Software of mainly includes microcontroller program, firmware program, driver program and application program. When receiving sampling drive signal the data acquisition system began acquisition pressure waveform and real-time display and collecting monomer pump working temperature. The simulation results show that the data acquisition system has a good stability, high accuracy, good real-time sampling.