CG125摩托车发动机怠速控制的研究

【作者】 潘盛军；

【导师】 吴锋； 胡章其；

【作者基本信息】 浙江大学 ， 动力机械及工程， 2002， 硕士

【摘要】 本文研究了发动机怠速控制的一种方法。众所周知，发动机怠速时不适当控制会增加燃油消耗、排放恶化、以及运行不稳定。 在本文中，控制方法上主要通过控制旁通空气量来改变怠速时的空燃比，旁通阀的开度是由步进电机来控制的。在控制策略上运用了模糊控制策略进行怠速控制，这种方法的优点是不需要为控制目标建立精确的数学模型。由于发动机的怠速运转是非常复杂的一个过程，所以要在发动机怠速的数学模型的基础上来设计控制器是很困难的。在本文设计的控制系统中，将89C51单片机作为控制器，分别进行了开环的控制和以转速为反馈量的闭环控制。控制系统的硬件、软件和执行机构步进电机的控制方法都在本文中进行了介绍。 为了验证控制系统的有效性，将原发动机与加上了控制系统后的运行情况进行了对比实验。实验结果表明，经过控制后，发动机的怠速运行状况，包括排放性和运转稳定性，都得到了很好的改善。更多还原

【Abstract】 This paper is concerned with a method for engine idle improvement. It is well known that inappropriate idling control increases fuel consumption and pollutant emissions, and also compromises stability.In this paper, idle performance control is realized by changing the air-fuel rate through changing the bypass air mass which is controlled by stepper motor. Fuzzy control method has been used to study engine idle speed. This method has advantage in not making mathematical model for the controlled object. The proceedings of idle speed are so complex that it is very difficult to design a good controller based on the mathematical model of gasoline engine idling condition. In the system, this paper refers a MCS-89C5 1 single chip computer is taken as the controller, engine speed as the feedback signal. The hardware and software of the system, the method to control the stepper motor as an actuator have been discussed in detail in this paper.To prove the effectiveness of the control system, a comparison of idle performance respectively by the original carburator engine and the carburator with the control system. The results show that with the closed system to control the engine idle process, the idle running quality is greatly improved and the engine speed fluctuation is remarkably reduced. It proved that the control system is useful and effective for raising engine idle performance.更多还原