Research On Establishment Of Measurement Model For Tire Road Contact Three-dimensional Force

Tyre plays the role of transfer force and torque between vehicle and pavement.The study of tyre-pavement 3D-force can guide the prediction of early pavement damage and the optimization of road design.It is also a prerequisite for analyzing vehicle dynamic performance and developing and improving vehicle control system.In recent years,with the advantages of small size,convenient installation and high measurement accuracy,micro sensors has been widely studied and used to measure tyre-pavement 3D-force.The indirect force measurement method is based on the acceleration,displacement,strain and other physical quantities directly measured by these micro sensors embedded in tires.The emphases of the above researches focused on the development of the sensor’s own structures,or the processes of using the existing sensor to build the measurement system,which lack of correlation analyses and researches on the rationalities of sensor distribution and force decoupling scheme.How to optimize sensor distribution and improve the reliability of measurement results has become an important problem to be solved.In order to solve the above problems,this paper takes the measurement method of the displacement sensor embedded in the tire as an example to carry out research.The main work content and innovations include:(1)Taking 11.00R20 truck radial tire as the research object,the finite element analysis model of tire was established by parametric modeling method.The effectiveness of the model is verified from the aspects of inflation size,grounding area and subsidence.(2)The mathematical relationship between the three-dimensional force of the tire and the displacement of each point on the tire is established by using the multiple nonlinear regression model,and the regression model is simplified.The results of the simulation calculation show that the mathematical relationship between the three-dimensional force of tire road surface and the displacement of tire large deformation area can be accurately described by the multiple nonlinear regression model with quadratic term.The error of the predicted value of three-dimensional force under each test condition relative to the preset value is less than ± 2%,and that of the simpler regression model is less than± 8%.(3)Guided by the accuracy of the fitting relationship between force and displacement,the optimal placement of displacement sensors is determined,and a complete three-dimensional tire force measurement model is proposed.On the center circle of tire inner liner,the arc area which deviates from the grounding center by no more than ± 15 ° can ensure the obvious displacement response and high accuracy of force calculation,which is the reasonable location of displacement sensor.According to the theoretical analysis results,the proposed tire road three-dimensional force measurement scheme can adjust the force calculation scheme according to the real-time position of the displacement sensor,so as to realize the continuous force measurement.The research method and qualitative conclusion of this paper can be extended to the establishment of other types of tire and road force model and sensor distribution model,which provides a theoretical basis for tire road three-dimensional force measurement scheme.