Control Strategy Based Tc1796 High Pressure Common Rail Diesel Sub-cylinder

Compare to traditional mechanical controlled diesel fuel injection system, High pressure common rail diesel engine can better adjust to the increasing rigorous emission regulation with lower fuel consumption as well as improved engine operating performance. Unlike some mechanical controlled dieselengines, such as the plunger engine or the distribution engine, the timing of high pressure common rail diesel engine is decided upon ECU to processing the position signal of crankshaft and camshaft,instead of the timing gear, since no mechanical connection exist between injection actuator and crankshaft. The accuracy of TDC1, which can be used to infer the angel phase at different moment, is strongly interconnected with the inject precision of high pressure common rail diesel engine which in turn have a direct influence on the performance of engine operating and emission.The main task of engine position determination control policy is to know the position of TDC1, then the instant and average rotational speed can be calculated from the angel phase of different moment in the engine and position signal from sensoron crankshaft. The main task is to use ECU to acquire and process the position signal from crankshaft and camshaft, so position information between them and TDC1as well as the phase angel of engine at different moment can be maximally retrieved. Then all these data is the input of ECU to guide the actuator in the injection system.This paper used YN30CR high pressure common rail diesel engine as research target to devise acontrol policy. The usual approach is use advanced vehicle MCU TC1796to verify the reasonableness of rectangle signal from crankshaft aswell as camshaft first, then combined with rotational speed of engineto know the angel phase of engine, finally, the phase angel of engine can be calculated from fixed angel difference between TDC1and miss tooth and add tooth, which were decided by miss tooth in crankshaft and add tooth in camshaft. Due to the poor working environment of engine, the acquired signal might have error or distortion, where several control mode are needed. If the camshaft break down in dynamic reasonableness detection, backup mode#1(single crankshaft cylinder Detection mode)will be used to assume the injection phase, which in turn can be used to know the TDC1position of engine after the fuel injection. By the same token, backup mode #2(camshaft Cylinder Detection mode) will be used if crankshaft break down to know the TDC1position from the fixed angel difference between camshaft and TDC1. These two modes are used during fault status, not suitable for long timeoperation.The main content of cylinder detection policy is to implement these three mode of cylinder detection.The implementation is based on diesel engine tectonics,C program design and MCU principle, in combine with advanced vehicleMCU TC1796as well as DAvE(Digital Application Virtual Engineer), Tasking EDE(Embedded Development Environment) software development environment, to determine the operating phase through frequency multiplying and rotational speed calculation, finally achieve the goal of cylinder detection.This paper first introduced the technical approaches and main vehicle MCU adopted in and out of china, after complete analyses all the tasks the cylinder detection should implement, three applicable control mode of cylinder detection, then frequency multiplying signal, single reasonableness, implementation of threecylinder detection mode and program output are explained in details.Finally, the analyses base on experiment results were conducted,future effort needed is also proposed.