Research On Active Safety Control Strategy Of Pneumatic Electronic Brake Based On Vehicle State Estimation For Commercial Vehicle

With the rapid economic development,China’s commercial vehicle industry is booming.Commercial vehicles have the characteristics of large mass,high center of mass,and large volume.Under emergency driving conditions,commercial vehicles are prone to instability,which brings huge hidden dangers to the driving safety of the vehicle.The pneumatic electronic brake active safety control system can effectively improve the driving state of the vehicle under emergency driving conditions and improve the driving safety of the vehicle.Therefore,it is of great significance to study the commercial vehicle active safety brake control based on the commercial vehicle pneumatic electronic braking system(EBS,Electronic Braking System).This paper is based on the National Key R&D plan sub-project— “Research on the Brake-by-wire Control Technology of Plug-in Hybrid Electric Bus for Emergency Automatic and Regenerative Braking”(No.2018YFB0105905-02).An improved design of a commercial vehicle pneumatic EBS configuration scheme is carried out.The pressure response characteristics of the pneumatic EBS and its key components of the double channel axle modulator are studied by AMESim simulation.On this basis,an active safety control strategy for commercial vehicle pneumatic electronic braking based on vehicle state parameter estimation is designed.According to the improved design of the commercial vehicle pneumatic EBS configuration scheme,a pneumatic EBS active safety control hardware-in-the-loop test bed was built.And through the test bed,the commercial vehicle pneumatic electronic brake active safety control strategy based on the estimation of vehicle state parameters is tested and researched under different working conditions.The specific research work carried out in this paper is as follows:(1)An improved commercial vehicle pneumatic EBS configuration scheme is designed.The internal structure,working principle and kinematic equations of the double channel axle modulator which is the key component of the pneumatic electronic braking system,are studied through testing and disassembly.The simulation model of the double channel axle modulator and th pneumatic electronic brake system are established in the AEMSim simulation software.And on this basis,first studied and analyzed the double channel axle modulator and the pneumatic electronic brake system open-loop pressure response characteristics.Then the influence of the key parameters of the EBS on the pressure response characteristics of the double channel axle modulator and the pneumatic electronic brake system is studied and analyzed.(2)For commercial vehicle pneumatic electronic brake active safety control,when estimating longitudinal vehicle speed and the sideslip angle,there are problems such as low estimation accuracy,strong nonlinear coupling of vehicle systems,and unknown time-varying sensor noise.An improved strong tracking adaptive cubature kalman filter estimator is designed.The estimator is based on the cubature kalman filter algorithm with high estimation accuracy,and then the improved strong tracking filter algorithm with strong robustness and the Sage-Husa estimator with adaptive sensor noise estimation are respectively combined.(3)In view of the problem of vehicle model parameter perturbation and external disturbances affecting the performance of commercial vehicle pneumatic electronic brake active safety control.Taking the sliding mode control theory and the nonlinear disturbance observer theory as the main lines,combining improved adaptive sliding mode approaching law technology,second-order sliding mode technology,and RBF adaptive neural network technology,the ABS,ESC,and RSC control strategies for the active safety control of the pneumatic electronic brake of commercial vehicles are designed.And on this basis,according to the vehicle instability hazard level and the rollover limit threshold,combined with the ABS control strategy,a combined control strategy for the electronic active safety control of the commercial vehicle air pressure is designed.(4)The commercial vehicle pneumatic electronic brake active safety control strategy combined simulation platform based on vehicle state parameter estimation is built through the MATLAB/Simulink,Truck Sim,AMESim simulation software.The MATLAB/Simulink software is used as the main simulation environment,and the commercial vehicle pneumatic electronic brake active safety control strategy model is built in MATLAB/Simulink.The vehicle dynamics model and the pneumatic electronic braking system model are built in Truck Sim and AMESim simulation software respectively.Finally,under different simulation conditions,the feasibility and control accuracy of the commercial vehicle electronic brake active safety control strategy based on the estimation of vehicle state parameters are simulated and analyzed.Simulation research shows that the above-mentioned control strategy has a good control effect and can effectively improve vehicle driving safety.(5)Based on the commercial vehicle pneumatic electronic brake system and real-time system,a hardware-in-the-loop test bed for the active safety control of commercial vehicle pneumatic electronic brake is built.Under different conditions,the active safety control strategy of commercial vehicle pneumatic electronic brake based on vehicle state parameter estimation is carried out on the hardware-in-the-loop test bed.The hardware-in-the-loop test results further prove the effectiveness of the above control strategy.