| Double clutch Automatic Transmission is a combination of manual Transmission andhydraulic Transmission mechanical Automatic Transmission (Automatic Transmission) isa little bit, make the DCT vehicles with the AT the driving convenience and comfort ofvehicle, and has better than AT the vehicle fuel economy, on the other hand, because theDCT and MT with similar structure and components of the inheritance of MT gearboxproduction conditions, thus reduce manufacturing cost of DCT. Therefore, in recent yearsthe DCT has become the hotspot in research of automobile transmission technology.For equipped with dual clutch automatic transmission of power transmission system,according to the research status at home and abroad, relying on the national "863" project(2012AA111712)"industrialization of dual clutch automatic transmission technologydevelopment shift quality objective assessment and the technical development of digitalcalibration" research, carried out based on the model of dual clutch automatic transmissioncontrol parameter optimization research. Based on DCT auto transmission systemdynamic performance, engine with dual clutch for shifting process, fully explore doubleclutch with the optimal control of engine torque the core problem, carried out includingDCT dynamic system modeling, control of quality index is put forward, control qualityparameters sensitivity analysis, the optimal torque of engine with dual clutch control arediscussed, the specific analysis includes the following several aspects.1、Scientific discussion followed by the dry dual clutch automatic transmission routeof the mechanical structure development concept and practice of implementing strategy,based on d ’alembert principle of Newtonian mechanics system, adopt the method ofexperiment combined with theoretical research, this paper constructs the covers engines,dry dual clutch, double intermediate shaft type transmission, the drive shaft of ontology,the DCT system dynamics control differential equation set of the wheel assemblynumerical model. Establish objective characterization of the engine to the wheels drive system dynamic response characteristics of the mathematical model. Then, define theengine torque, dual clutch friction torque for the system control, road surface resistancetorque for the system disturbance variable, transmission parts speed as state variables. Anda simulation model built in matlab/simulink environment, the simulation to verify theeffectiveness of the DCT assembly modeling work. For quantitative study of double clutchengagement process dynamics as well as the description phase shift optimal double clutchwith matching engine torque adjustment strategy to provide necessary theoretical premise.2、According to the research target, considering the power performance and fueleconomy of vehicles, transmission durability, comfort aspects of performance, put forwardto control the quality evaluation index, specific refers to the shift time, impact degree,index of fuel economy, energy density, power density and acceleration vibration dosevalues. Model sensitivity analysis can be used to study the input parameters on the resultof quantitative model, in order to verify the rationality of the selected indicators, this paperUSES the extension in the fu Ye Min sensibility analysis, to vehicle performance and fueleconomy, comfort and durability as test variables, the impact degree of indicators such asinput parameters, consult the related literature at home and abroad, to determine the modelparameters a priori range, sensitivity to measure the objective function is established.Global sensitivity analysis results verify the effectiveness of the selected evaluation indexhas a significant influence on the model output, on the impact of the precision of themodel is relatively larger. Finally through numerical derivation, theoretically proves therelationship between control parameters and evaluation index, put forward in this paper,finally the control variable for the engine output torque and torque of the clutch. Providesa theoretical basis for the subsequent control optimization.3、Double clutch cover the engine power system assembly, dry dual clutch ontology,the transmission to drive train wheels powertrain and electric double clutch actuator fourmodules. Due to the shifting phase of engine with dual clutch comprehensive optimalassociation with engine output torque control performance must be reasonable regulationwith double clutch sliding friction torque, so should satisfy solution of optimal matching control performance index of the engine output torque and the analytical solution of thedouble sliding friction torque of the clutch. Therefore, the second chapter, first set theobjective characterization of the engine to the wheels drive system dynamic responsecharacteristics of the mathematical model. Then, define the engine torque, dual clutchfriction torque for the system control, road surface resistance torque for the systemdisturbance variable, transmission parts speed as state variables. According to the abovedefinition state space expression of the whole drive train dynamics model is establishedcombined with the actual control requirements put forward to control the quantity andstate variable phase coupling control functional performance, according to the minimumprinciple in optimal control theory, and combined with the dynamic responsecharacteristics of transmission system of mathematical model for solving the time domainadduction torque and inertia phase is concise and accurate torque analytical solutions, soas to achieve the goal of control parameter optimization, objective, concise analyticalsolution makes the control targets, control law solution is intuitive, simple and efficient.To fully embody the dry DCT high transmission efficiency and the comfort, service life,good fuel economy, performance and low manufacturing cost and comprehensiveadvantages such as simple structure. |
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