Mine Dump Truck Tire Parameter Identification And Brake Comfort Optimization

Mining dump truck is an important transport equipment of modern mines,occupies two-thirds of the market share in large open-air mine transportation.Mining dump truck loading capacity big and uneven load,have bad road conditions,due to these objective conditions lead to front axle shaft increase sharply,dump truck tires and suspension deformation become bigger,body will produce strenuous vibration and generate significant"brake pitch"phenomenon when actual braking.This kind of phenomenon not only reduces the service life of parts,but also seriously affected the driver's comfort and safety.Therefore,the study and optimization of mine dump truck brake comfort is very necessary.As the only part of the car that directly contact with the road,its performance parameters have an important influence on the vehicle driving performance,including brake comfort.Additionally,dump truck tires vast size,its high investment cost and limited corresponding test conditions lead to its parameters cannot be obtained through experiment at present.Therefore,this article puts forward the method of tire parameters identification based onimproved EKF-BP neural network,effectively identify tire parameters,and on the basis of parameter identification,optimize the vehicle brake comfort.It is significant for reducing vehicle development costs and improving the level of development.Main contents of this article are as follows:1.Aiming at the defects of BP neural network,using the extended kalman algorithm to replace the BP network learning algorithm and introduce setting factor in the network,build improved EKF-BP network which has high learning efficiency and high prediction accuracy,providing the identification method for subsequent parameters identification.2.Design vehicle driving test under the random road and pulse case,and obtain the vertical acceleration signal of the tire center and the seat.Aiming at the condition of the test data contains too much noise,using wavelet threshold denoising method to deal with the noise on the test data,and comparative analysis the three methods of the Fourier denoising,wavelet soft/hard thresholding denoising results,to obtain the optimal denoising result,providing more effective test data for subsequent work.3.Simulate tire dynamic simulation on the bases of establishing tire-pulse road finite element model,use improved EKF-BP network to identify tire material parameters,and verify the identification ability of the improved EKF-BP network through comparing with the standard BP network and the EKF-BP network.Additionally,according to the tire denoising acceleration signal,this article identified and verified the tire material parameters.Design virtual bench test based on the identification tire,analysis the tire pressure,vibration frequency and amplitude on the influence of the tire vertical stiffness damping,according to the analysis result,eventually get tire vertical stiffness damping.4.Based on the identification parameters vehicle dynamics model,analyzing of the mine dump truck brake pitching phenomenon.This article use interval uncertainty optimization method to optimize the mining dump truck brake comfort with taking oil-gas suspension parameters as optimization variables,taking cargo capacity,centroid position and speed as uncertainty variables and taking pitching angle and pitching angle acceleration as the optimization goal.Finally,this article analyzes the optimization results on the influence of the vehicle ride comfort.