Research On The Consistency Of Safe Speed Acquisition And Braking Coordination For Heavy Commercial Vehicle

With the increase of national investment in the commercial vehicle market,the number of commercial vehicles continues to grow,and serious traffic accidents of heavy commercial vehicles have become particularly prominent.To reduce the number of traffic accidents of heavy commercial vehicles,this paper will combine domestic and foreign research,from the speed limit sign recognition,road factors,and load on the impact of safe speed,and the tractor and trailer braking discoordination problem,the specific research content is as follows:(1)According to the main characteristics of speed limit signs,a speed limit sign recognition method based on HSV color space transformation combined with Le Net neural network model is proposed.Firstly,image preprocessing is carried out.Secondly,the ROI region is extracted based on image preprocessing.Finally,the Le Net neural network model is trained to classify the extracted ROI images to obtain the speed limit value of the speed limit sign,which provides a basis for the subsequent heavy commercial vehicles to maintain a safe speed.(2)To reduce the safety problems such as the rollover of heavy commercial vehicles,a rollover evaluation standard for heavy commercial vehicles was proposed.Firstly,the Trucksim/Simulink joint simulation was used to verify the correctness of the rollover evaluation criteria for heavy vehicles under different working conditions;Secondly,according to the evaluation criteria,the impact of single factors such as curve radius on the safe speed of heavy commercial vehicles when passing through the curve is studied.The speed data is obtained through the intersection test simulation,which is fitted and compared with the typical safe speed model in Matlab;Finally,the influence of road adhesion coefficient and load on the safe speed of heavy commercial vehicles when passing through the curve is studied to obtain the safe speed of vehicles.(3)To solve the problem of the low accuracy of the model in Truck Sim,the simulation model of the pneumatic brake system of a heavy commercial vehicle was re-established.Firstly,the AMESim simulation model of each component of the braking system is established.Secondly,according to its actual function,the simulation results are analyzed.Finally,the pipe is connected to the real car,and the dynamic characteristics of the pneumatic braking system of the whole vehicle are analyzed.The feasibility of the pneumatic braking system model can be concluded from the results..(4)A coordinated control strategy is proposed to solve the problem of uncoordinated braking between the tractor and trailer of heavy commercial vehicles.Firstly,the hysteresis of the trailer braking system is analyzed,and the PID control algorithm is used to improve the braking pressure response time,which is increased by about 0.5s.Secondly,a coordinated control strategy is established based on slip rate and ABS anti-lock braking control,and the proposed control strategy is verified jointly by AMESim/Simulink/Trucksim.Finally,it can be concluded from the results that the strategy can effectively reduce the force at the tractor-trailer hinge by about 9000 N,prevent the wheels from clinching in advance,and improve the braking stability of heavy commercial vehicles.Figure [77] Table [13] Reference [86]...