Study On ATM Clutch Starting Control Method Based On Double Design Objective

The automated mechanical transmission (AMT) can replace the manualtransmission by canceling the clutch pedal and adding automatic manipulation systemby microcomputer control to realize shifting automation, a robot system is controlled bythe ECU unit to complete clutch operation and selection or shifting action. Due to itdoes not change the structure of traditional clutch and transmission, AMTkeeps manualtransmission’sadvantages of high transmission efficiency, low manufacturing cost,simple structure and good manufacturing succession, and has AT’s virtue of simplemanipulation, but also exists some similar control trouble with manual transmission.The starting control is a difficulty of AMT control key technologies. In startingprocess, vehicle traveling should be smoothly and no impact and try to reduce slippingfriction workto guarantee clutch’s service life. So good or bad of clutch starting controlperformance directly affects automobile starting quality and clutch friction plate’sservice life. In this paper, it focuses on several aspects of analysis and research for AMTclutch starting control as follows:①Firstly, the evolutionof automatic transmission and now several automatictransmissionon the market are introduced, the constitution, classification, workingprinciple and control key technologies of automatic mechanical transmissionareanalyzed, and the development history and research status of automatic mechanicaltransmission are summarized at home and abroad.②Second, the basic structure, function and working principle are introduced, thestarting joint process and starting control evaluation index degree of jerkand Sliding-frictionWork of vehicle clutchare analyzed. Vehicle starting clutch joint process issimulated analysis by engine constant speed starting control strategy.The results showsthat engine constant speed starting control strategy, degree of jerk is used asdesignobjective, can meet the starting comfort requirement. But at some throttle openings, theclutch joint would generate excessiveSlipping work which can cause excessivetemperature rise influencing clutch’s service life, more seriously, it could result inclutchworking unstable even failureinfluencing automobile travel security.③Aiming at the issue of engine constant speed starting control strategy, the clutchstarting control method based on double design objective is proposed. The degree ofjerkand Slipping workis used as double design objective to realize the combinationcontrol of clutch starting for fully embodying driver’s intention. ④The influence of the engaging speed of clutch and the target rotate speed toSliding-friction Work when the vehicle is starting is analyzed theoretically. And thetheoretical analysis is verified by using Matlab/Simulink. The clutch starting controlstrategy of double design objective is established and simulation andanalysis of thestarting control is conducted.The result of the simulation shows that the clutch startingcontrol strategy of double design objective can control the degree of jerk of vehiclestarting and Slipping work, satisfythe requirement of vehicle starting comfort andtemperature rise.⑤The change of control parameters of the clutch of slope-starting and level roadstarting is analyzed. The influence on the Slipping workwhen the clutch is engaging ofslope-starting is analyzed theoretically. In the end, simulation andverification of vehicleSlope-starting is finished by Matlab/Simulink. Double design aims of clutch controlstrategy are used in simulation and analysis of vehicle slope-starting.The result showsthat the degree of jerkand Slipping work can both satisfy the requirement ofvehiclestarting comfort and temperature rise.