CN-116691697-B - System and method for identifying characteristic parameters of vehicle driving pavement

CN116691697BCN 116691697 BCN116691697 BCN 116691697BCN-116691697-B

Abstract

The invention discloses a system and a method for identifying the characteristic parameters of a vehicle driving road surface, wherein the method comprises the steps of determining the dominant parameters representing the mechanical characteristics of the road surface, measuring the wheel force/moment and the slip rate, and estimating the estimated value of the dominant parameters of the road surface according to the measured values; and then comparing the estimated value of the road surface dominant parameter with data in a road surface parameter database to obtain the current road surface type. The invention can quickly track the road surface parameter change caused by the wheel motion state change or other factors, does not need to consider the influence of illumination and weather environment, has high calculation speed and strong robustness, and is suitable for online analysis.

Inventors

ZHENG XIAODONG
ZHANG DONGLIN
BI SHENG
BAI YINGCHUN
CHENG QING
XIA GUANG

Assignees

安徽合力股份有限公司

Dates

Publication Date: 20260512
Application Date: 20230602

Claims (6)

1. A method for identifying the characteristic parameters of a vehicle running pavement is characterized by comprising the following steps: step 1, determining dominant parameters representing the mechanical properties of the current pavement; step 2, measuring the wheel force, the wheel moment and the slip rate of a vehicle running on the current road surface; step 3, estimating an estimated value of the road surface dominant parameter according to the measured value in the step 2, and then comparing the estimated value of the road surface dominant parameter with data in a road surface parameter database to obtain the current road surface type; The dominant parameters in step 1 are road surface basic mechanical characteristic parameters which affect the interaction force between the road surface and the wheels to the greatest extent, and the road surface basic mechanical characteristic parameters comprise two groups of parameters which are pressure-bearing characteristic parameters And shear characteristic parameter ; The dominant parameter is determined by the following method: step 41, after the accelerator pedal is depressed to a certain position, keeping unchanged, and calculating the current wheel slip rate value; step 42, calculating the longitudinal force of the wheel at the current wheel slip rate according to the following formula , Step 43, obtaining the relative sensitivity RS of the wheel force to the road surface basic mechanical characteristic parameter according to the following formula: Wherein r is the radius of the wheel and b is the width of the wheel; And The approach angle and the departure angle of the wheels are respectively, A component in the x-direction of the shear stress to which the wheel is subjected; the positive stress of the wheel is that i is the characteristic parameter of each road surface, and y is the wheel force; step 44, sequentially calculating and storing RS values of the basic mechanical characteristic parameters of each pavement, sorting the RS values in groups, and selecting groups Sum group The parameter with the largest RS value is used as the dominant parameter.
2. The method for identifying the characteristic parameters of the running pavement of the vehicle according to claim 1, wherein the pressure-bearing characteristic parameters comprise cohesive force modulus, internal friction angle modulus and subsidence index, and are specifically expressed as the pressure-bearing characteristic parameters ; The shear characteristic parameters include cohesion, internal friction angle and shear deformation modulus, and are specifically expressed as the shear characteristic parameters ; Wherein, the For the modulus of cohesion, the modulus of the material, The modulus of internal friction angle, n is the subsidence index, c is the cohesion, phi is the internal friction angle, and K is the shear deformation modulus.
3. The method for identifying the characteristic parameters of the running pavement of the vehicle according to claim 1, wherein the wheel force and the wheel moment to be measured in the step 2 comprise a wheel vertical force, a wheel longitudinal force and a wheel driving moment; The measuring equipment comprises a gyroscope, a torque sensor, a rotating speed sensor and a GPS.
4. The method for identifying the characteristic parameters of the running pavement of the vehicle according to claim 3, wherein the method for measuring the force/torque and the slip ratio of the wheels is as follows: Step 61, detecting the vertical force of the wheel: The longitudinal acceleration and the lateral acceleration of the vehicle during running are measured through a gyroscope, and then the vertical force of the wheel is calculated, wherein the calculation formula is as follows: Wherein, the 、、 And The vertical force of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel respectively, m is the mass of the whole vehicle, L is the wheelbase, a and B are the distances from the mass center to the front and rear shafts respectively, h is the height of the mass center, B f and B r are the wheelbase of the front and rear shafts respectively, and a x and a y are the longitudinal acceleration and the lateral acceleration respectively; Step 62, detecting wheel longitudinal force The wheel longitudinal force F x is calculated from the following formula: Wherein r is the radius of the wheel; Step 63, detecting the driving moment of the wheel: A torque sensor is arranged on a wheel shaft, and the driving torque T of the wheel is measured through the torque sensor; Step 64, detecting slip rate: The calculation formula of the wheel slip ratio s is as follows: Where w w is the wheel speed and V is the vehicle speed, where w w is measurable by a speed sensor and V is measurable by GPS.
5. The method for identifying the road surface characteristic parameters for vehicle driving according to claim 1, wherein the method for estimating the road surface dominant parameter in the step 3 is as follows: First, the wheel stress expression is approximated, and the following fitting function is defined: Wherein, p represents the stress of the wheel, including normal stress and shear stress, and θ m is the maximum stress angle; Defining the wheel intermediate entry angle θ 1m and the intermediate exit angle θ 2m as: The coefficients of the fitting function described above can be determined from the stress values at three points, θ i 、θ im and θ m , respectively: Wherein, the ; Will be , And The substitution formula can obtain a unified expression: Definition of the definition And Then: Wherein, the The final simplified round-robin interaction resolution model: Wherein the method comprises the steps of ; Meanwhile, the driving torque T can be simplified as: Wherein, the ; The dominant parameters are then estimated using kalman filtering according to the following equation: Wherein, the Is a state function of the system; For the measurement function, W is the process noise and V is the observation noise.
6. A vehicle driving road surface characteristic parameter identification system is characterized by comprising the following modules: the dominant parameter identification module is used for calculating, analyzing and determining dominant parameters capable of representing the pavement characteristics and sending the result to the estimator module; The sensor module is used for measuring wheel force, wheel moment and slip rate and sending the measured values to the estimator module; The estimator module is used for receiving the values of the dominant parameter identification module and the sensor module and identifying the dominant characteristic parameters of the unknown pavement; a processor for executing the computing code; The memory is used for storing the calculation codes and the parameter identification results; The dominant parameters refer to basic mechanical characteristic parameters of the road surface which affect the interaction force between the road surface and the wheels to the greatest extent, and the basic mechanical characteristic parameters of the road surface comprise two groups of parameters which are pressure-bearing characteristic parameters And shear characteristic parameter ; The dominant parameter is determined by the following method: step 41, after the accelerator pedal is depressed to a certain position, keeping unchanged, and calculating the current wheel slip rate value; step 42, calculating the longitudinal force of the wheel at the current wheel slip rate according to the following formula , Step 43, obtaining the relative sensitivity RS of the wheel force to the road surface basic mechanical characteristic parameter according to the following formula: Wherein r is the radius of the wheel and b is the width of the wheel; And The approach angle and the departure angle of the wheels are respectively, A component in the x-direction of the shear stress to which the wheel is subjected; the positive stress of the wheel is that i is the characteristic parameter of each road surface, and y is the wheel force; step 44, sequentially calculating and storing RS values of the basic mechanical characteristic parameters of each pavement, sorting the RS values in groups, and selecting groups Sum group The parameter with the largest RS value is used as the dominant parameter.

Description

System and method for identifying characteristic parameters of vehicle driving pavement Technical Field The invention relates to the technical field of engineering vehicle pavement identification, in particular to a system and a method for identifying vehicle running pavement characteristic parameters. Background The engineering vehicle has complex operation environment, changeable running road condition and usually meets field soft muddy road. Because of the unstable road surface structure of the soft road surface, and the bearing capacity is poor, the sinking amount of the wheels is large when the vehicle runs, so that the running resistance is increased, the shearing strength is low, the road surface is easy to generate shearing deformation, the wheels slide seriously, and even the chassis support can generate the phenomenon that the vehicle is trapped. In order to sufficiently ensure the steering stability and the passing performance of the vehicle, the road surface type must be effectively discriminated, and the road surface characteristic parameters must be accurately discriminated. In the aspect of pavement parameter identification, mainly there are Newton iteration method, coupling solution method, neural network method, etc., but Newton iteration method needs at least three sets of test data as input to solve the convergence solution, coupling solution method needs to solve the mechanical equation of high coupling, neural network method needs a large amount of test data. The method has certain limitations, and a driving road surface parameter identification method which is free from environmental influence, fast in calculation and strong in robustness is needed to be provided. Disclosure of Invention The invention aims to solve the technical problem of providing a system and a method for identifying the characteristic parameters of the vehicle driving road surface aiming at the defects related to the background technology so as to improve the accuracy of the identification result of the characteristic parameters of the vehicle driving road surface, thereby providing a basis for higher-level motion planning. The invention adopts the following technical scheme for solving the technical problems: A method for identifying a characteristic parameter of a road surface on which a vehicle is traveling, comprising the steps of: step 1, determining dominant parameters representing the mechanical properties of the current pavement; step 2, measuring the wheel force, the wheel moment and the slip rate of a vehicle running on the current road surface; and step 3, estimating an estimated value of the road surface dominant parameter according to the measured value in the step 2, and then comparing the estimated value of the road surface dominant parameter with data in a road surface parameter database to obtain the current road surface type. Further, the dominant parameters in the step 1 refer to basic mechanical characteristic parameters of the road surface, which affect the interaction force between the road surface and the wheels to the greatest extent, and the basic mechanical characteristic parameters of the road surface comprise two groups of parameters, namely a pressure bearing characteristic parameter and a shearing characteristic parameter. Further, the pressure-bearing characteristic parameters comprise cohesive force modulus, internal friction angle modulus and subsidence index, and are specifically expressed as pressure-bearing characteristic parameters The shear characteristic parameters include cohesion, internal friction angle and shear deformation modulus, and are specifically expressed as the shear characteristic parameters Wherein k c is the cohesive modulus,Is the internal friction angular modulus, n is the collapse index, c is the cohesion,And K is the shear deformation modulus. Further, the dominant parameter is determined by the following method: step 41, after the accelerator pedal is depressed to a certain position, keeping unchanged, and calculating the current wheel slip rate value; Step 42, calculating the wheel longitudinal force F x at the current wheel slip rate according to the following formula, Step 43, obtaining the relative sensitivity RS of the wheel force to the sinking index according to the following formula: Wherein r is the radius of the wheel, b is the width of the wheel, theta 1 and theta 2 are the approach angle and the departure angle of the wheel respectively, tau x is the component of the shearing stress applied to the wheel in the x direction, sigma is the normal stress applied to the wheel, i is the characteristic parameter of each road surface, and y is the force of the wheel; And 44, sequentially calculating and storing the RS values of the basic mechanical characteristic parameters of each pavement, sorting the groups, and selecting the parameter with the largest RS value in the group G Ⅰ and the group G Ⅱ as the dominant parameter. Further, the wheel force and