【作者】 黄涛；

【导师】 周云飞；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2007， 博士

【摘要】 面对能源紧缺、排放控制法规日益苛刻以及对动力性要求不断提高的局面,如何实现高效率、高动态性能的汽车发动机控制是当前亟待解决的问题。由于发动机复杂的工作过程难以精确建模,其工作环境和工况复杂多变,并且这些问题往往具有非线性的特点,因此要求发动机控制系统具有较好的鲁棒性和非线性控制性能。本文在讨论发动机电喷控制系统组成的基础上,阐述了电喷系统的控制要求,提出了一种基于发动机测控网络的系统结构。分析了发动机空燃比控制系统中进气子系统和燃油供给子系统的物理过程及其数学模型,针对发动机系统这类非线性、时变、模型非常复杂的被控制对象,讨论了基于模糊滑模控制的空燃比控制方法,并给出了相应的仿真结果。在对点火信号和爆震信号进行小波分析的基础上,论述了小波变换在处理点火系统信号方面的优势,在此基础上提出了一种基于小波观测器的爆震控制方法。该方法通过离散小波变换,从爆震信号中抽取出特征点,通过使用模糊推理系统实现点火提前角的自适应控制。同时,采用小波分析实现对闭合率的动态自适应控制以产生平稳的点火能量。试验结果表明了这个方法的可行性。由于网络化可以极大地简化电气路线,由此提高车载控制系统的可靠性。但是由于网络传输的延迟,以及控制系统在强干扰状态下所产生的通信错误会造成控制系统的性能下降甚至破坏系统的稳定性,而这些问题都表现出随机性和非线性特点。本文从系统的角度讨论了控制网络同步方法和发动机控制网络模型,提出基于滑模变结构的发动机网络控制方法,分析了该方法的稳定性并给出了仿真结果。在上述分析的基础上,本文讨论了控制系统的实现问题,包括发动机电子控制单元,点火控制模块,传感器节点设计以及车载CAN监控网关和远程CAN管理模块的设计。由于发动机控制系统是在强干扰环境中工作,设计时必须保证控制系统具有较强的抗干扰能力,因此本文还讨论了发动机控制系统中干扰源的特性及相应的软硬件抗干扰设计方法。本文最后介绍了系统试验环境的构建,分析了系统在相应的模拟测试环境下运行的结果,并在此基础上简要介绍了已经在各种实际系统中得到成功应用的部分实例。更多还原

【Abstract】 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.更多还原