The High Pressure Common Rail Diesel Engine Cylinders Work Evenness Detection And Control

For the traditional mechanical control diesel engine, the control for cylinder imbalance cannot be achieved because of the cylinder imbalance cannot be detected and the fuel injection for each cylinder cannot be controlled precisely. With the emergence of electronic-controlled diesel engine, the control for cylinder imbalance becomes possible. In order to combine detection and control for each cylinder, precise condition detection, rapid electronic-control and controlled injection are indispensableAccurate, fast electronic control is the only way for automotive engines to meet increasingly stringent performance indicators currently. High-pressure common rail is the most advanced control mode for diesel engine and the main direction of development. Its high injection pressure, the real-time detection from all kinds of sensors and precisely controlled fuel injection provide the necessary conditions for cylinder imbalance control. Cylinder imbalance concerned with crankshaft torsion vibration, vibration, noise, power, emission and life of the engine. Due to less fuel injection, small reciprocating inertia force and low speed, the cylinder imbalance is most evident when the diesel engine at low idle condition. It is very important to optimize NVH (noise and vibration roughness) characteristics for idling condition when electronic-controlled diesel is used for saloon car.Using YN30CR electronic-controlled diesel of KUNMING YUNNEI POWER as carrier, an algorithm which is based on band pass filters was designed. Firstly instantaneous speed signal was accessed through the crankshaft signal sensors, and then it was processed by low-pass filter and resample. According to speed frequency and in the form of band pass filters, the uniformity of cylinder by cylinder was obtained. In order to gain the specific oil correction, PI algorithm was used.Detection and control for each cylinder are the center of CUC (Cylinders Uniformity Control). Digital signal processing and internal combustion engine dynamics are the theoretical tools. LabVIEW (U.S. NI), ASCET (Germany ETAS) and MATLAB are the application tools. Optimize the uniformity of the cylinder as the ultimate goal of work. In the algorithm design process, the three application tools should be integrated application. At the beginning, making use of the NI data acquisition card to get the off line instantaneous speed signal, then put it into the LabVIEW program directly to complete the process of the signal and verify the results, then calculating the correct amount of oil required for each cylinder for the final result. If the LabVIEW program has been finished, the construction and parameters come from LabVIEW program and the MATLAB will be integrated to calculate the digital filter difference equation to complete the ASCET program. So this function to import electronic control module in the overall programThere are some functions and influence of the CUC in ECU, but it just uses the information that has been collected for the original (such as crankshaft signal period). Therefore, CUC would not add any hardware cost. Computing Resource of the electronic control unit (ECU) is the only consumption. In order to save computing resources as much as possible, under the premise of ensuring the actual effectiveness of CUC, how to determine various parameters will be repeated throughout the functional design. This will be obvious in ASCET software.Research status and development trends are described firstly in this thesis. Before listing the technology roadmap of goals, the needs and characteristics of CUC was comprehensive analyzed. After finishing further structural analysis and overall design, the specific implementation steps were confirmed. Firstly, using the LabVIEW software which has high functional integration and user-friendly human-computer interaction to make early development, and then converted it to ASCET form which is more fitting low-level hardware. When the result of non-uniform detection was preliminary validated, the follow-up vision has been put forward.