Study On The Diesel Engine Speed Control System For Heavy Truck With AMT

Automated Mechanical Transmission(AMT) is one kind of high technology products which adapts to the situation of China nowadays, and is more efficient and has a lower cost than traditional automatic transmission(AT), also has the advantage of low cost and easiness to manufacture, moreover has the characteristic of good inherited attribute and low equipment investment.As for the heavy truck, it is the aim to reduce the work intension of the driver, fuel consumption, the abrasion of the clutch and driveline to adopt AMT. Diesel engine is usually used as the power for the heavy truck. Because there is no predominant condition of relaxing shock and vibration than AT in the driveline, to reach the goal of lessening engine noise and clutch friction work in the starting and shift process of AMT, there is need of the automatic control of diesel speed in the starting and shift process, so the heavy truck can start and shift smoothly. The control of diesel speed is an important part of AMT control system.Diesel engine speed control during starting and shift process for heavy truck with AMT is researched in the paper, the main contents are shown as follows:1,A general design of the diesel engine speed control with AMT is given, especially actuators for the electronic timing system is selected by the analysis and comparison. Electromagnetic actuator, which is applied extensively at present in control system, is selected as the actuator which adjusts rack displacement of diesel engine injection pump.2,The control algorithm of the timing system is researched and the fuzzy control and PID control used commonly nowadays are adopted in this paper. According to diesel engine speed control target during starting and shift process, the fuzzy and PID controller are designed.3,Engine speed characteristic has direct connection with the AMT control system, engine speed characteristic is analyzed and dynamic model of diesel engine and the actuator is established. At the same time, the injection pump's characteristic is also studied.4,Starting and shift process are analyzed in detail, and the control target of diesel engine speed is determined, then is simulated in Matlab/Simulink. The simulation result shows that the control strategy provided in the paper satisfies the engine's speed control demand of the AMT system.