【作者】 单一鹏；

【导师】 尧命发；

【作者基本信息】 天津大学 ， 动力机械及工程， 2011， 硕士

【摘要】 中国经济的快速发展加剧了国内能源需求,由于石油能源的不可再生性,替代能源的研究愈发重要。以天然气、沼气和煤层气为代表的气体能源成为短期内最有效的替代燃料。本文针对工业燃气发动机的特点和使用要求,研究和开发了一套适用于多点喷射燃气发动机的电控系统。首先,本文对工业燃气发动机控制系统进行了分析,构建了控制系统的基本框架。在控制系统的开发过程中,使用了基于模型的设计开发方法,让设计者将主要精力集中在数学模型的建立和验证上,不必过分关心硬件的变化和底层代码的编写,提高了开发效率。本文将控制系统分为四个核心模型:过量空气系数模型、恒转速控制模型、燃气喷射阀驱动模型和发动机基本保护模型,并分别进行了深入的研究。在过量空气系数模型中,使用速度—密度法进行空气和燃气流量的预测,并对该算法加以改进,同时加入了过量空气系数的闭环修正。在恒转速控制模型中,应用了一种具有更好稳定性和响应速度的PID控制算法。在燃气喷射阀驱动模型中,通过采用电流自适应算法尽可能降低驱动电流,从而延长了喷射阀的使用寿命。核心控制模型建立完成后,本文利用发动机平均值模型,从软件和硬件在环两方面对控制模型进行验证。试验结果表明,模型控制输出稳定,且在外界的连续扰动下,仍然能控制发动机模型稳定运行,控制模型及其算法可靠。最终将所开发的电控系统在一台12V190发动机上进行试验验证,稳态和瞬态试验结果表明,发动机空燃比及转速的控制精度和动态响应速度均能满足控制要求,证明本文开发的ECU控制系统适用于工业燃气发动机。更多还原

【Abstract】 With the fast development and prosperity of the economy of China, requirement of energy sources increasing rapidly. As petroleum is a non-renewable energy resource, the research of alternative fuel sources become more and more important, especially on natural gas, bio-gas and coal gas. And the gaseous energy source could be the most effective alternative fuel sources in short period of time. In this paper, a set of electronic control unit (ECU) applying for multi-point injection gas engine was developed, according to the characteristics of gas engine and the operation conditions.First of all, the fundamental framework of the ECU control system has been constructed after analysis on the characteristics of that. And by using the model-based method during the development process on the ECU control system, the designers could make engagement in the establishment and calibration of mathematics model without concern about the variation of hardware or compiling the basic code, which make the development process efficiently.There are four core models in the ECU control system which are excess air ratio model, constant speed control model, gas injection valve drive model and basic engine protection model separately. The prediction of air and fuel gas flow rate has been made in the excess air ratio model by means of speed-density method that is improved and regulated with the closed-loop correction on the excess air ratio. A better stability and response can be obtained in the constant speed control model using a new PID control method. And by applying the current self-adapting algorithm, the drive current can be reduced decline as low as possible in the gas fuel injection valve drive model and therefore the life span of inject-valve can be prolonged.After finished the ECU control models, a simple engine mean value model was build using Simulink which used to test the reliability of the software control models and the response of hardware equipments. The results show that stable output of the control model can be obtained even with a sustained interference signal, which means the control model and arithmetic are reliable.Experiments have been carried out in a 12V190 industrial gas engine to calibrate the ECU control system, and the stable and the transient experimental results show that control precision and response rate of the excess air ratio and speed can satisfied with the industrial gas engine control demand. Therefore the developed ECU control system is suitable for industrial gas engine.更多还原