Research On AMT Starting Control Strategy Of Mini Vehicle

With the urban traffic congestion becoming more and more obvious and fuelconsumption costing more and more money, a smaller and more fuel efficient mini vehicleis already accepted by the auto market gradually. Mini vehicle has many advantages such assmall size, light weight, reasonable price, low fuel consumption. With the popularity of themini vehicle，the automatic transmission system which can be more applicable to be used inmini vehicle is concerned by automobile transmission company. Because of thecharacteristics of Automatic mechanical transmission (AMT) which is simple structure、easymaintenance、low cost and light weight, AMT is seen as the first choice of the gearbox ofmini car. The main objective of AMT clutch launch control is keeping small jerk in launchand small friction. However, because of the light weight of mini vehicle, slight impact in theprocess of starting the car will cause much more discomfort for passengers. So, the AMTstarting control strategy of mini vehicle is more complex than others. And, compared toother gearbox, AMT clutch starting control is a nonlinear and complex process. AlthoughAMT clutch control strategy system has been improved, there are many difficulties yet. Thispaper makes a study of the AMT clutch starting control strategy and raise some new controlstrategies on the clutch launch control considering different conditions.1) In order to make mini vehicle driving slowly to follow the front car in urbancongested road or adjusting the car slowly in parking place, this paper presents an improvedcreeping launch control strategy.Because there is no acceleration process in this strategy,the vehicle speed and engine speed are very low. So, this creeping strategy has not adoptedthe common idea which control the clutch in fixed speed. The clutch engaging of the newcreeping strategy has different rate which is variable based on the principle of the enginespeed stability. So the process of clutch engaging to some position which is before theslipping position will not affect the speed of engagement and this process will be much smoother.2) To maintain a stable of vehicle speed this paper raises the fuzzy control strategywhich is based on the maintaining of input shaft speed.This control algorithm has been welltested and verified in the way of vehicle test on road.3) Summarized the experience of the previous control theory,in the process ofaccelerated launching, this paper raises a new control algorithm called engine Localconstant speed control algorithm. This control algorithm fully considers that rate of speed oftransmission input shaft can affect process of launching the car. Because of the gearboxinput shaft speed rate is directly related to the load of the vehicle, so the improvedaccelerating controller can satisfy the AMT launching control goals much better.4) Because the clutch in long-term used will make some wear and clutch torquetransfer point can be changed. For this problem, this paper proposed a control method inwhich the clutch torque transfer point can be studied.5) Finally, this paper will establish the monitoring and calibration environment inCANape, correct the calibration parameter in control strategy and verify the effectiveness ofthis new control strategy through the real car multi-loading road test.