Semi-Physical Simulation Test Of Braking Performance Of ABS Bus

In the development mode of ABS,the pure numerical simulation environment is too ideal,the cycle of real vehicle test is long,and its cost is high.The hardware-in-the-loop simulation(i.e.semi-physical simulation)combined the advantages of both of the above.In the experiment,the hardware device which is difficult to be expressed by the simulation model is embedded in the simulation environment through the computer.The emergence of hardware-in-the-loop simulation technology shortens the development cycle of bus ABS and reduces the cost of development.On the basis of domestic and foreign research results about hardware-in-the-loop simulation platform and ABS control algorithm,the scheme of bus ABS hardware-in-the-loop test system based on x PC target real time simulation platform is proposed.The system can realize the real-time simulation of the braking performance of ABS bus,which provides a simple and efficient way to evaluate the performance of the bus straight line braking.The main research contents of this paper include:(1)Using real-time simulation platform based on x PC target,the communication connection between host and target machine is established,and the data transmission is realized.Use C language to write data acquisition card driver.Use the data acquisition card to realize the sensor signal acquisition of the air brake system and the digital output of the control signal of the ABS regulator.(2)Designed and built the air brake system of bus ABS hardware-in-the-loop test system in accordance with the actual bus air braking system.It has two braking circuits.Mainly including the gas tank,the four circuit protection valve,the total valve,the first relay valve,follow-up valve,brake gas room,ABS regulator and other parts.(3)The mathematical model of the vehicle dynamics is analyzed,and the dynamic simulation model of the vehicle is established by Simulink.Including tire model,seven degrees of freedom vehicle model,brake model,auxiliary calculation model,etc.Design parameter self-tuning fuzzy PID control and logic threshold control method.According to the GB7258-2012 the operation of a motor vehicle safety technical conditions,ABS braking tests for bus with high adhesion coefficient road surface,low adhesion coefficient road surface,open road surface and docking road surface were done on bus ABS hardware-in-the-loop test system.The test results are compared with the test results of no ABS bus under the same test conditions.In this paper,the bus ABS hardware-in-the-loop simulation technology was studied.The results have a certain role in promoting the research of hardware-in-the-loop simulation and bus ABS control algorithm and expected to provide a bit of help to the field of passenger car ABS braking.