Influences Of TPS Wear Conditions On Auto Driving Performance

The Electronic Fuel Injection System (EFI) is one of the most important electronic control systems in the modern automobile. It can acquire the different engine working conditions with the sensors, which installed on the engine, and control the fuel injection and the advanced angle of ignition precisely. Then the sufficient torque will be exported with the lower oil consumption and lower emission. As the most important sensor in the EFI system, the output of Throttle Position Sensor (TPS) influences the fuel injection directly. In this thesis, the influence of TPS wear conditions on auto driving performance is studied. It is proved that the driving performance will be declined when TPS worn. So this research of the thesis has important practical significance. In this thesis, an aerodynamics model of the throttle valve is established.According to this model, the relationship between the open angle of the throttle valve and the air intake volume is simulated. Then the relationship between the output voltage of TPS and the air intake volume are analyzed. The feedback mechanism of TPS is introduced in the thesis. According to the structure and working principle of TPS, the reason why TPS be worn out easily is analyzed. A wear mechanism is design to simulation common wear conditions of the TPS. Then the wear TPS sensors in urban and rural condition are compared with the new TPS sensor. The influence on the air intake volume in the same open angle by the worn TPS sensors is studied.Experiments which include the auto NVH test and road test are design to prove that the worn TPS has great influences on the driving performance. The results show that a worn TPS sensor will caused the bad driving performance. At the same time, a set of subjective evaluation index is put forward to distinguish the influence on the driving performance by different wear conditions TPS. These indexes including speed-raising, noise stability, idle stability, rotate speed stability, shift consistency and fuel consumption.The influence of TPS wear conditions on auto driving performance such as the descendent performance, under power, speed instability, higher fuel consumption and noises is proved in theoretical analysis and experimental verification. The results show that with the mileage increase, the driving performance's decline is not only related to the mechanical system's wear condition, but also related to the electrical sensors wear condition.