Research On Fully Electronically Regulated CVT Electronic Control System

Metal belt continuously variable transmission(CVT)compared with other types of transmission,CVT in the continuous change of speed ratio at the same time to ensure uninterrupted power transmission,so that the engine is always in the best working state in the process of operation.Electro-Mechanical Continuously Variable Transmission(referred to as EM-CVT)removes the traditional energy-consuming oil pump and uses the electric motor to replace the oil pump to adjust the speed ratio.Compared with the traditional hydraulic controlled CVT,EM-CVT reduces energy consumption and improves fuel economy.Based on the analysis of the structure and working principle of EM-CVT,this paper puts forward its speed ratio control strategy and speed ratio control method,and designs the software and hardware of EM-CVT control system.The main work includes the following aspects:(1)The structure and working mechanism of EM-CVT are analyzed,with emphasis on the implementation mode and requirements of speed ratio control of EM-CVT.Based on the analysis of the functional requirements of EM-CVT control system,the design method of EMCVT electronic control system is proposed,and the controller resources are allocated,which provides the theoretical basis for the design of EM-CVT electronic control system.(2)Control strategies under different operating conditions during vehicle driving are designed.Simulation models of various modules,such as speed ratio actuator,target speed ratio and vehicle transmission,are built according to the mathematical model of EM-CVT.Combined with the engine model constructed through cubic spline interpolation,the vehicle model of equipment EM-CVT is finally completed.(3)Based on the advantages of traditional PID algorithm and artificial bee colony algorithm(ABC),ABC-PID control algorithm is designed and applied to EM-CVT speed ratio control.The feasibility of this algorithm in EM-CVT speed ratio control is verified through simulation.(4)Design the hardware and software of EM-CVT control system.Based on MC9S12G96 microcontroller,design the interface circuit to execute motor speed input,analog input and switching input,and complete the design of output interface circuit and serial and CAN communication interface circuits.The main program and modular subroutine are designed.In view of the environment interference,the software uses the extreme value discrimination filtering,the median filtering,the first order lag filtering to process the acquisition signal,as far as possible to improve the acquisition data accuracy;(5)For the problem of speed ratio control interference,the corresponding anti-interference method is designed.In order to obtain the best performance of the electronic circuit,the general principle of PCB design is followed.The rationality and feasibility of the EM-CVT electronic control system are verified by the experiment of EM-CVT electronic control system.