Acquisition System of Cylinder Pressure in Diesel Engine

To improve cylinder pressure acquisition system and optimize system configure to fit on-board operation, dynamic acquisition methods including pressure acquisition measure, acquisition mechanism and data communication are studied. By means of comparing pressure data file capacity, partial acquisition area between 50 degrees CA (crank angle) before TDC (top dead center) and 100 degrees CA after TDC is presented. Digital Signal Processor (DSP) is used as acquisition's core to replace person computer due to its ADC 10bit sampling precision and high-speed parallel deal function, high speed USB (Universal Serial Bus) communication are introduced into dynamic acquisition to enhance speed of pressure data transmitting. PCI-TI type Fiber Pressure Sensor (FPS), DSP56F807, USB transmitting circuit are selected, dynamic acquisition system of cylinder pressure based on DSP is developed. Bench test of this system is made in 4100QB diesel engine, change trend of pressure curves obtained by Kistler combustion instrument and this system respectively in same profile is basically consistent in combustion process. Testing results showed that dynamic acquisition system of cylinder pressure based on DSP can meet the demand of diesel engine.