Control Strategy Study For The High Pressure Common Rail Diesel

In the face of an increasingly rigorous world energy shortages and higher requirements for the emissions regulations, it is necessary for diesel to be developed with lower pollution, lower fuel consumption and high power per weigh. Furthermore, with the development of microcontroller and electronic controlled technology, electronic control system makes the diesel engine qualitative, quantitative, time is possible, because the working parameters of diesel can be monitored by ECU at any moment and then ECU could provide optimal injection timings, fuel injection quantity and injection pressure through calculation of running program. Thus, it improves fuel combustion in diesel cylinder and keeps the good performance of power, economic and exhaust of diesel. Electronic controlled high pressure common rail is one of the three breakthroughs of internal-combustion engine industry in the end of 21st century. Because its desired fuel injection law. The electronic control system has become a research hotspot at present; At the same time, As the car heads toward the direction of energy efficiency, comfort and safety, which adds more controllers to the automotive, thus brings challenges to the algorithms of engine power distribution. In this context, development model and control algorithms have become to be the major bottleneck in th development of ECU.In order to break this impasse of the ECU development, the V development mode populared in embedded system currently has been introduced into the ECU project of high pressure common rail diesel engine. And on this platform, the old control algorithm based on oil was replaced by the torque-based control algorithm.At first, the paper deeply analyses and studies the hardware and software platform based on V development model, and then completed the construction of a series development, simulation and test platform such as SIL, RCP, HIL and so on. Second, on this platform, the torque-based control strategy was analyzed, modeled and simulated, especially, the idling conditions was under taken detailed in-depth study, and the simulink model of torque-based idle speed control was done. Third, the autocode generation technology was deeply reseached combining with the torque- based idle speed control. The last, the calibration techonology for the ECU of high pressure common rail was studied considerfuly, and the calibration for the ECU of idle condition with the tool of CANape was done, mean while, the advanced automatic calibration technology was studied and discussion.In this paper, based on the in-depth study for the software and hardware development platform of V mode, a series of development and test platform such as SIL,RCP,HIL and so on based on Simulink-dSPACE were constructed completely as the first time; torque-based algorithm control model of high-pressure common rail diesel engine at idle condition has been estabilished originally, and combined these comprehensive control strategies of multi-injection, each cylinder balancing and PID control creatively, solving the problem of idle speed instability; Focusing on the problem of rail pressure fluctuation caused by the oil injection and natural characteristics of fuel injector, the combination control strategy of pre-control and PID bas been promoted, and eliminating the fluctuation of rail pressure successfully. The contruction of these platforms provided the whole ideal and efficient platform for the platform-based development of V mode; The control algorithm model can be taken as the basis and foundation for the following development; These control strategies gone through with the validation of simulation and experimental successfully could be meaningful for the development of high pressure common rail system.