Design And Study Of Exhaust Energy Recovery System Controller Of Hybrid Electric Vehicle

Recycling the exhaust gas energy is an effective mean to improve the fuel efficiency.The recycling exhaust gas energy system is recycled the exhaust gas energy and stored in battery which can be used for auxiliary power source to provide energy therefore,the exhaust gas energy can also improve the fuel economy of the hybrid vehicle,reduce the emission and reduce energy dissipation.In this paper,take a hybrid vehicle as a research object,the corresponding exhaust gas energy recovery control strategy is establishment and designed according to the achievements of our research team.The feasibility and practicability of the fuzzy control strategy and the controller is validated.The main contents of this paper are delivered as followings:(1)The fuzzy control strategy of the exhaust energy recovery system is designed which the output parameters(the turbine guide vane angle and the bypass valve opening)are controlled by the input parameters(speed of the turbine,generator current,exhaust back pressure and SOC value of battery).The fuzzy domain and fuzzy subset of the input signals and output signals are partitioned.The fuzzy rules of the fuzzy signals is established and the fuzzy controller is defuzzification at last.(2)The acquisition system for each signal of the exhaust energy recovery system is established which including the acquisition of exhaust back pressure signal,the acquisition of the battery SOC value,the acquisition of turbine speed signal and the executive body selection of variable geometry turbocharger selection and exhaust bypass valve.QY545B-002-type pressure sensor is used to measure value of the exhaust back pressure;ACS712 linear current sensor is used to collect the current signal of SOC;PICOTURN turbocharger speed measurement system is used to measure value of the speed of the turbine;the BYG stepper motor is used as the executive body of variable geometry turbocharger and exhaust bypass valve.(3)The hardware circuits of the exhaust gas energy recovery system are designed: including the selection of the control chip;the design of the power conversion circuit;the conditioning circuit of the exhaust back pressure signal,battery signal and turbine speed signal;the driving circuit of the stepper motor;the virtual serial interface circuit and the analog signal acquisition circuit.And the circuit board is made on the basis of the circuit design.(4)The fuzzy controller program including the main control program,fuzzy control program and the stepper motor control program is written and debugged.The experiment data is recorded under the combination of the hardware circuit and the software program.Comparing the experiment data and the surface observer of fuzzy control rules and analyzing the cause of the error,the stability and reliability of the hardware circuit and the rationality of the software program is validated.