High Pressure Common Rail Diesel Engine Supercharger Regulator (PCR) System Control Strategy

In recent years, due to the declining of environment quality, governments around the world have strengthen the monitoring of vehicle exhaust emission, enacted more stringent emission regulations. what a primary problem the car manufacturers concern is that, how to optimize the engine for the work process, reduce emissions of harmful gases and fuel consumption and increase engine power.Through research the status and development trend of the technology between home and abroad, paper analyzed the mechanisms, advantages and disadvantages of some types boost pressure technologies, compared the impacts on engine performance. The pressure charging regulation (PCR) system of high-pressure common-rail diesel engine was used as object for control strategy, advanced variable geometry turbocharger (VGT) was selected as actuator of system development. The designed PCR system must precisely drive the vane of VGT and realize an exact match between VGT and engine in full working conditionsThe control strategy is based on the installed sensors in the diesel engine, the designed control strategy will gather the real-time signal on working engine, in order to calculate the needs of mass air under current conditions, precisely control the vane's angle change, to meeting the torque demand of real-time response to driver, in order to improve engine performance. The process of system design and development is based on the advanced V development model, for the urgency of time, mainly to complete the left side of V-model development process:First, by researching the engine work process, completed the function definition of control system and sub-module; next, using the ETAS company's software development tools ASCET, to complete each module of the control strategy to establish; most Control strategy after extensive simulation experiments and verify system input and output response. Through offline simulation results showed that:the design of control system could accurate monitor the real-time condition, and calculate the variable nozzle turbocharger operating angle to engine operating conditions, Precisely control mass air flow, assist engine to get optimal air-fuel ratio, greatly enhance the engine performance.This system could realize that:1,To improve engine characteristics in transient accelerate response, increase torque in low-speed and prevent excessive PM;2,By increasing the vane of VGT at high speed,could increasing the cross-sectional area of exhaust flow in order to avoid the speed of turbocharger and decrease NOx emission;3, eliminating the involvement of a sense of the turbine,and increasing the operating comfort, safety in the turbocharged vehicle。...