Research On Air-fuel Ratio Control Strategy Of Premixed Gas Engine Based On AUTOSAR

National emission regulations become more and more stringent nowadays.Thus natural gas engine system is getting more and more popular.On the other hand,the control accuracy requirements of automotive module are higher than ever before in the automotive electronics industry.And the control unit becomes more and more complicated.In order to standardize the software interface,facilitating the porting and maintenance of software,the AUTOSAR architecture came into being.Therefore,the air-fuel ratio control strategy of premixed gas engines based on AUTOSAR architecture is deeply studied and designed in this thesis.In this thesis,the fuel electronic throttle and air-fuel ratio system are analyzed and the corresponding mathematical models are established.Since the fuel electronic throttle is the most important actuator of air-fuel ratio system,it's strongly nonlinear and its parameters are difficult to obtain.Hence an adaptive sliding mode control strategy is proposed.Based on the fuzzy control theory,an adaptive control strategy of boundary layer during sliding mode motion is proposed to reduce the chattering of the system.And finally the stability of the system is proved.Aiming at the time delay problem in air-fuel ratio control,this paper proposes a discrete model predictive control strategy based on state space,and then Laguerre function is introduced to reconstruct the problem and optimize the controller,which greatly reduces the computational complexity of the model predictive control algorithm.The guiding principle of Laguerre function parameter design is given.Finally,the problem of controller constraints is solved by active set method,and the stability of the system is proved.The effectiveness of the control algorithm is verified by the joint simulation of Matlab/Simulink and GT-Power.This thesis implements the basic architecture of AUTOSAR based on Infineon's 32-bit microprocessor TC1782.By introducing the idea of model-based design,this thesis completed the embedded implementation of the electronic throttle and air-fuel ratio controller,and packaged it into the application layer software of AUTOSAR.At this point,the construction of the experimental software platform is completed.Finally,the Weichai WP10 engine was used as the control object,the physics experiment platform was built and the bench experiment was carried out,which achieved good experimental results.The results prove that the sliding mode controller of electronic throttle system and the model predictive controller of air-fuel ratio system designed in this thesis have ideal practical effects and have a good application prospect.