Study On The Control Strategy Of Electric Control Air Processing Unit For Commercial Vehicle

With the rapid development of the automobile manufacturing industry,China’s commercial vehicle manufacturing industry is also constantly transforming and upgrading.The performance of commercial vehicle electronic controller hardware has been improving,while the changing market demand of commercial vehicles has also driven the development of technology.Commercial vehicle electronic control air processing unit(Air Processing Unit,APU)is a core component of the commercial vehicle air pressure braking system,which mainly undertakes the air pressure regulation,filtration and drying function of the vehicle braking system compressed air.At present,the air processing unit still has the following key problems:(1)moisture drying performance is not enough,the air processing system air path is easy to ice,air processing system and air brake parts are prone to rust;(2)regeneration rate adjustment through the time switch open-loop control,the control system does not storage cylinder finished gas drying degree feedback,regeneration gas volume can not be automatically adjusted according to the finished gas drying degree,resulting in the waste of finished gas or incomplete recovery of drying performance;(3)the electronically controlled APU mode control strategy based on speed and speed control cannot reasonably reduce fuel consumption and improve vehicle power performance.By improving the above-mentioned problems of APU of commercial vehicles,the safety,power and fuel economy of commercial vehicles can be improved.To this end,this paper takes a certain type of commercial vehicle electronically controlled air processing unit as the research object and focuses on its performance characteristics and control system as follows:(1)The research background and significance are introduced,the performance characteristics of the electronically controlled APU and the current status of domestic and international research are analyzed,the development trend of commercial vehicle air processing units are investigated.The current problems and shortcomings are pointed out,and the main research contents of this paper are proposed.(2)The air treatment unit and its system structure are introduced,the control system structure and working principle of the electronically controlled APU are described,and the evaluation indexes of the air treatment system,including dew point drop,air compressor duty cycle and regeneration rate,are given.(3)A regeneration volume control strategy based on dew point estimation is proposed to reach the regeneration volume,a general framework of the regeneration volume system is established,and the hardware system and software strategy of the regeneration volume control method are designed.The strategy was verified by experiments.(4)An electronically controlled APU control strategy based on neural network and Markov chain prediction is proposed by means of commercial vehicle engine operating conditions study,neural network-based engine operating conditions pattern recognition and Markov chain-based demand torque percentage prediction.The mathematical model and Simulink system simulation model of the commercial vehicle air processing unit control system were established,and the control system simulation of the aforementioned APU control strategy was carried out using Simulink.The results show that the proposed study has optimized control effect and peak-valley balance characteristics.(5)A summary of the full paper is presented and future research directions are envisioned.This paper provides an in-depth study of various aspects of electronically controlled air processing units,which provides useful references for future related research.