Research On Granular Computing Optimization Fuzzy Control For Clutch Of Wet DCT During Vehicle Launching

Dual clutch automatic transmission (DCT), which inherits the advantages of both manual and automatic transmission, has characteristics such as high transmission efficiency, high shifting comfort etc. It is an ideal vehicle power transmission device and has become one of the research hotspots among the major vehicle companies. During vehicle starting, the clutch control problems have serious nonlinearity, time-varying, modeling difficult and so on properties, and its control quality affects the working performance of DCT directly. Therefore, it is one of the difficulties and core in the DCT control.In this paper, granular computing optimization fuzzy control method is proposed for the two problems during DCT vehicle starting process, which are clutch control problems and rules redundancy problem in its fuzzy control. The decrease of fuzzy rules’ number and does little impact on clutch engaging and starting performance are taken as its optimization objectives to optimize clutch fuzzy control during DCT vehicle starting. And the following aspects are mainly studied.1. The development of dual-clutches transmission is surveyed and integrated, and the DCT structure, working principle and clutch control technology research status during its starting are analyzed.2. Multi-plate wet clutch structure, working principle and characteristics are introduced, and the wet clutch engagement process during DCT vehicle starting, vehicle starting quality and the two evaluation indicators are mainly analyzed.3. According to the clutch control problems during DCT vehicle starting, the fuzzy inference rules of driver’s starting intention and the fuzzy rules of clutch target oil pressure is formulated based on the drivers’ experience and experts’ knowledge. And the DCT vehicle starting fuzzy control system is founded.4. According to the fuzzy rules redundancy problem, the fuzzy rules reduction based on granular computing is applied to the clutch target oil pressure fuzzy rules. It reduces the number of the fuzzy rules and optimize the fuzzy.5. Simulation model of DCT vehicle starting is established in the MATLAB/ Simulink and SimMechanics platform. The starting process is simulated separately with clutch fuzzy controllers before and after optimization by granular computing. The control results before and after optimization with relevant indicators is analyzed and compared, and the implementation of the optimization objectives is verified as well.