Research On Hardware In The Loop Testing System For Pneumatic Braking Performance Of Commercial Vehicle

The improvement of pneumatic braking performance of commercial vehicles is an effective means to ensure the driving safety of vehicles,which is closely related to the structure and control method of pneumatic braking system.The pneumatic braking system of commercial vehicle involves the vehicle structure,pneumatic circuit and control system,etc.So it is difficult to achieve good braking performance by developing the pneumatic braking system only through theoretical analysis and model simulation.Therefore,this paper orients the hardware-in-the-loop testing for pneumatic braking performance of commercial vehicle,uses a combination of theoretical analysis,simulation testing and system testing to study and design the versatile,accurate,realtime,and stable hardware-in-the-loop testing system for pneumatic braking performance.of commercial vehicle.The main research work of this thesis is as follows:(1)According to the relevant domestic and foreign standards of the automobile braking system,evaluation parameters and evaluation indexes of commercial vehicle pneumatic braking performance are studied.Based on the analysis of functions of the hardware-in-the-loop testing system,main functions of the hardware-in-the-loop testing system for pneumatic braking performance of commercial vehicle are determined,and the hardware-in-the-loop testing system is overall designed.(2)According to the overall design scheme of the hardware-in-the-loop testing system for pneumatic braking performance of commercial vehicle,the design scheme of the pneumatic circuit of the hardware-in-the-loop testing system is proposed,and pressure characteristics of the pneumatic circuit model are simulated and analyzed.The pneumatic braking test bench of the test system is designed and strength check is carried out.The dSPACE real-time simulation system and the pneumatic braking test bench are integrated,and the hardware-in-the-loop testing system based on dSPACE is built.(3)According to the overall design scheme of the hardware-in-the-loop testing system for pneumatic braking performance of commercial vehicle,the signal processing system of the hardware-in-the-loop testing system for pneumatic braking performance of commercial vehicle is designed to achieve the collection of test signals and the output of control signals.The dynamic model of the hardware-in-the-loop test object is established and verified,and the man-machine interface of the hardware-inthe-loop test system is designed.(4)According to the pressure characteristic and the braking characteristic test method of the pneumatic braking system,the hardware-in-the-loop test is done on the test system,and test results are compared with offline simulation results to verify that the hardware-in-the-loop test system developed in this paper has functions of the pressure characteristic test and the braking characteristic test of the pneumatic braking system.The hardware-in-the-loop testing system for pneumatic braking performance of commercial vehicle studied and designed in this paper can provide a testing platform for the development of pneumatic braking system products,and it is a useful attempt for the application of hardware-in-the-loop testing technology in the development and testing of pneumatic braking system products of commercial vehicles.