Research Of Launching Control Strategy Of Automatic Clutch System

With the development of automotive technology of electronic control andthe higher and higher requirements of the car driving comfort, theinconvenience brought by manipulating the clutch pedal becomes more and moreobvious. Then Automatic Clutch System(ACS) appears for settling thisproblem.ACS also is one of the core technologies of AMT. Control strategyis one of the key technologies of ACS, especially the launching controlstrategy. So, this paper lucubrated in the launching control strategy of ACS.Main research and innovation are the following:1.The paper researched in the vehicle running model, enginestabilization model, clutch model and the diaphragm, which established thebase for vehicle simulation and making good launching control strategy ofACS. Two important parameters were brought out from view of the vehiclecomfort and clutch life: jerk and friction work. And the main influencefactors of jerk and friction work were analyzed.2.The clutch engagement model and engagement process were studied, thenthe dynamics functions of engine and clutch disc during the phase of frictionand synchronization were got. The clutch engagement process and therequirements for the clutch engaging speed during the engagement process werestudied in detail. And the rule of clutch engaging speed is totally"fast-slow-fast".3.Because the influence factors of clutch friction torque before and afterthe moment of synchronization are different, jerk is prone to being very bigat the moment of synchronization. A method that the clutch friction torqueapproaches that on the moment of synchronization was raised to settle aboveproblem. The moment of equivalent inertia transformed from the vehicle mass Jaand resistance torque TΦare variable and influence the clutch frictiontorque and jerk at the moment of synchronization, so the calculation methodsof these two parameters were given.4.The control strategy of clutch target friction torque was establishedwith the engine speed and difference between engine speed and disc speed asinput.The method of fixing the clutch target stroke with the curve of clutch frictiontorque-engagement stroke was raised. The control strategy of clutchengagement speed was established with engine speed, clutch engagement stroke,difference between engine speed and disc speed, temperature as input. Thecontrol strategy of clutch disengagement speed was given with the temperature,difference between engine speed and disc speed as input. The method of testingthe curve of clutch friction torque-engagement stroke was given. And thecalculation method of maximum permitted engagement speed was established.5.The launching control strategy of ACS with the vehicle driving systemwas simulated. And the simulation results at different wide of throttle,different vehicle mass, different slope were given and validated the good ofthe launching control strategy of ACS at different working condition.The research on the launching control strategy of ACS in this paper makesthe jerk during the launching satisfy the requirement, which improved thecomfort during the launching. And it reduces the clutch friction work, whichcan enhance the clutch life.