Research On The Key Technologies Of Engine Fuel Injection Control System

In the face of energy shortage, harsher emission control regulations and ever-increasing demands for power, awaiting urgent solutions is the issue of how to achieve the automotive engine control with hi-efficiency and hi-dynamic-performance. The complicated working process of the engine poses the difficulty in precise modeling, and its working environments and operating conditions are complex and mutable, all of which usually display nonlinear; consequently, the engine control system is required to possess good robustness and nonlinear control performance.The thesis, on the basis of discussing the components of the engine electronic fuel injection control system, expatriates the control claims from the electronic fuel injection system, and thereby proposes a systematic structure based on engine testing network. By analyzing the physical process and its mathematic models of the intake and the fuel supply subsystems in the engine air fuel ratio control system, the paper expounds the air fuel ratio controlling methods based on fuzzy sliding mode control and analyzes the corresponding emulation results, in allusion to the nonlinear and time-variant controlled subjects with complex modeling as of the engine system.Built on the wavelet analysis of ignition signals and knock signals, the paper addresses the advantages that wavelet switch has in dealing with ignition system signals, and accordingly brings forward the wavelet-observer-based knock control method, which extracts feature points from knock signals by dispersing wavelet switch, fulfills the self adaptive control of the spark advance angle by using the fuzzy inference system, and adopts the wavelet analysis to implement the dynamic self adaptive control of dwell and produce stable ignition energy. The feasibility of this method has been attested by experiments.Amount of wiring harness can be reduced by application of networking, so the stability of on-car control system can be raised. But the delay in network transmission and in node response, and the communication error of the control system caused under strong disturbance environments, all may lead to the decline in the performance in the control system, and even disrupt the stability of the system; all of these problems demonstrate certain randomness and nolinear. The paper discusses the control network synchronization methods and the engine control network models from a systematic angle, puts forward the engine network control methods based on the sliding mode variant structure and analyzes the stability of the method and the simulation results.Based on the above analysis, the paper expounds the realization of control system, including the engine electronic control unit, ignition control module, sensor node design and design of on-car CAN surveillance gateway and remote CAN management module. As the engine control system operates under strong disturbance environments, it is necessary to maintain the strong anti-disturbance capability of the control system in the designing process, and the paper also deals with the characteristics of the disturbance sources in the engine control system and the relevant anti-disturbance design plans both software- and hardware- wise.The thesis concludes with the construction of the systematic experimentation environment, and, with the analysis of the results obtained from the system operating under the relevant simulation testing environment, briefly introduces some examples that have been successfully applied in all kinds of practical systems.