Research On Hardware-in-the-loop Simulation For Pneumatic Anti-lock Braking System Of Commercial Vehicle

The pneumatic anti-lock braking system(ABS)of commercial vehicles can effectively guarantee the driving safety.However,due to the late start of relevant technical research in China and the lack of research data,the technology is relatively backward,and most products in the market are from abroad now.In this paper,a hardware simulation platform using PXI as the core was set up to explore and study the pneumatic braking anti-lock system of commercial vehicles,which including the hardware model,the vehicle dynamics model,the interface model,real-time simulation model and human-computer interaction interface.This platform can effectively reduce the test cost,improve the repeatability of the test and avoid the danger of the real vehicle test under extreme operating conditions.This paper mainly conducts the following research work:Firstly,based on a commercial vehicle model of DONGFNEG,the hardware in the loop simulation platform was designed and built,including braking platform,wheel speed simulator and driving simulator.The whole vehicle dynamics model was established by using TruckSim,and the driver input,wheel speed sensor and braking system hardware in the loop was realized through the joint simulation with LabVIEW,which providing the ABS upper algorithm under multiple working conditions of hardware in the loop simulation experimental conditions.Then,through selected the slip rate as the control object and set the desired slip rate,the logic threshold algorithm model and the sliding mode control algorithm model of ABS were constructed by MATLAB/Simulink software.By setting the upper and lower threshold values,the slip rate was controlled within a larger range of the wheel adhesion coefficient and the logical threshold algorithm model is constructed.The sliding mode surface is established by slip rate deviation,and the sliding rate deviation is eliminated by controlling the braking torque,so that the slip rate remains near the desired slip rate,and the sliding mode control algorithm model is constructed.Finally,the pneumatic braking anti-lock system of commercial vehicles is tested by using the hardware in the loop simulation platform,including the following test content:experiment of ABS effecting or not under low adhesion coefficient;the comparison experiment of braking effect between logic threshold and sliding mode control under high adhesion coefficient;the experiment of the braking effect of sliding mode control algorithm under the condition of the braking on the docking road and on the open roadThe research results in this paper show that the developed hardware in the loop simulation platform has the test capability of ABS,and the designed ABS sliding mode control algorithm has relatively good control effect.This algorithm has the advantages of strong robustness and strong anti-interference ability,which can effectively guarantee the stability of the vehicles in the braking process.