汽车发动机冷却系统测控研究与设计

【作者】 蒋开正；

【导师】 姚伯威； 周翼翔；

【作者基本信息】 电子科技大学 ， 机械工程， 2005， 硕士

【摘要】 汽车现已是集机械、电子一体的高科技产品,但其仍存在很多结构和控制不完善的地方,汽车发动机冷却系统就是其中之一。本论文针对汽车发动机冷却系统存在控制不够完善之处而进行改进,采用智能控制技术对汽车发动机冷却系统进行控制,解决发动机冷却系统中存在的具体问题,以达到控制效果良好,提高汽车动力性和经济性,减小汽车的排放污染,从而实现节约能源和保护环境的目的,并提高汽车的使用寿命。在本课题研究中,通过对汽车发动机冷却系统进行测试与研究,找出了系统的影响因素和变化规律:发动机冷却系统冷却液温度受许多因素的影响,且这些影响因素大多是不断变化的,并与发动机冷却液温度呈非线性关系,发动机的冷却液温度与各影响因素间的关系很难用数学方程进行准确描述,且发动机的冷却液温度的升高和降低是一个缓慢变化和大滞后过程。根据发动机冷却系统此特点,论文提出了对发动机冷却系统采用模糊控制方法进行控制。论文详细阐述了本控制系统采用模糊控制的系统设计,包括系统模糊控制计算、系统结构设计、控制系统硬件和软件设计。将设计出的控制系统装于发动机进行试验,测试出了系统性能参数。通过对改进前后的发动机冷却系统测试的数据比较,发现改进后的控制系统达到了预期的目标:改进后的冷却系统,使发动机具有冷启动性能好,暖机时间短,排放的有害气体少,动力性和经济性改善等优点。本课题将模糊控制方法运用于汽车发动机冷却系统,这对于现代汽车的完善和不断发展,以及实现节约能源和保护环境具有重要的意义。这也为现代汽车发动机性能的完善提供了新的途径。更多还原

【Abstract】 Now automobiles are of high-tech products integrated with machines and electrons, but they still have many problems with their structures and imperfect control. The motor engine cooling system has such problems. Aiming at improving the imperfect control of the engine cooling system, this paper uses the intelligent control technology to control the motor engine cooling system, solve the concrete problems of the engine cooling system, achieve a good control effect, enhance the engine dynamic characteristics and its economy as well, reduce the automotive exhaust pollution, thus reaching the goal of saving the energy sources and protecting the environment, and prolonging the automobile service lifetime.In this research, after testing and studying the engine cooling system, the author finds the factors which influence the system and the changing rules. The coolant temperature of the engine cooling system is influenced by a number of factors, which mostly change unceasingly, and have a non-linear relationship with the engine coolant temperature. And it is difficult to accurately depict the relationship with mathematics equations. The rise and fall of the engine coolant temperature is a slowly-changing and greatly-lagging process. According to the feature of the engine cooling system, the author proposes employing the fuzzy control method to control the engine cooling system.The paper elaborates the control system design using the fuzzy control, including the system fuzzy control computing, the system structural design, and the control system hardware and software design. The designed control system is installed in the engine to test, and the system performance parameters are gained. Compared with the former system according the data, the improved system achieves the anticipated goal.更多还原