基于单片机控制的汽车空调制冷系统设计

摘 要 汽车是移动物体,外界气候条件变化大,车外热负荷变化大,汽车车内乘员密度大,要求的制冷能力大,所以乘客要求进入汽车后在很短的时间内就享受到空调的效果。因此与一般控制系统相比,空调的制冷控制更加困难，所以本课题设计基于单片机控制的汽车空调制冷系统，以达到最佳控制。 本课题设计的汽车空调制冷的单片机控制系统主要采用单片机控制技术实现在某些环境下对汽车空调制冷系统的精准控制，以便提高汽车空调的整体性能。系统通过控制鼓风机的转速变化和温度风门角度的变化，从而达到控制车室温度的目的。车室内温度的控制采用模糊控制，通过热敏电阻采集车室内温度 ,再与车室内设定温度相比较得误差值 ,进而决定控制量的大小。风门控制系统由三相六拍步进电机、 脉冲分配器、驱动电路和相应的传动机构组成，单片机根据控制量计算出步进电机转动的步数和方向，经传动结构改变温度门的开口大小。脉宽调制( PWM)输出直接由微处理器输出 ,通过变频器改变风机的供电频率，从而改变其运转速度，当需求风量减小时则降低风机转速，即进行减速控制，反之则提高风机转速，进行增速控制。 本空调系统通过车室内温度的变化，调节风机转速及温度门的开度，将单片机控制应用于汽车空调，在节能降耗和使用等方面都会有明显的效果。本控制系统操作简单、方便，较大地提升了对于汽车空调制冷的灵活性。 关键词： 汽车空调；单片机控制；风门控制；模糊控制 Abstract Motor vehicles are the moving objects, changes in external weather conditions, and changes in thermal load of the vehicle, and automotive vehicle occupant density, the cooling capacity requirements, and therefore require access to motor vehicle passengers in a very short time to enjoy the air conditioning on the results. Therefore, compared with the general control system, air-conditioning refrigeration control more difficult, so the subject of design is based on single-chip microcomputer-controlled automotive air conditioning refrigeration system to achieve optimal control. The design of automotive air conditioning refrigeration control system of single-chip single-chip computer control technology to achieve in some circumstances the car air-conditioning refrigeration system to control the precision in order to improve the overall performance of vehicle air-conditioners.System by controlling the blower speed and temperature changes in the changes in throttle angle to achieve the control purpose vehicle room temperature. Indoor temperature control vehicles using fuzzy control, through the acquisition vehicle thermistor temperature, and then with the car interior temperature, compared to a set error value, to determine the size of the volume control. Throttle control system by making six three-phase stepper motors, pulse divider, the drive to change the temperature structu