Whole vehicle plane mass center point positioning method

Abstract

The invention discloses a whole vehicle plane mass center point positioning method, and belongs to the technical field of vehicle control, and the method comprises the steps: S1, charging tires of a test vehicle to a vehicle standard tire pressure in a corresponding load state, covering four wheel load instruments with white paper, uniformly coating the wheels with black pigment, and hoisting the vehicle to a position right above the wheel load instruments; s2, the vehicle slowly falls down and is placed to a wheel load instrument, the wheel load instrument records four-wheel pressure values and then lifts the vehicle, and a camera is used for shooting pictures printed on paper every time after tire pigment makes contact with the paper, acquiring a contact area on paper in a picture in the camera to obtain a corresponding relation between the contact area of each wheel tire and the ground and the pressure of a certain wheel position acting on the ground in real time through the tire; and S3, installing an environmental chamber around the wheel load instrument, repeating the steps S1 and S2 to determine the data of the pressure compensation coefficient changing along with the temperature, and determining the pressure compensation coefficient according to the data of the pressure compensation coefficient changing along with the temperature.

Description

Technical Field

[0001] The invention discloses a method for locating the plane mass center point of a whole vehicle, and belongs to the technical field of automobile control. Background Art

[0002] The mass distribution of the inertial load (people and objects) of the vehicle during driving is uncertain, depending on the impact of road bumps, etc., and the number of passengers and the weight of items in the vehicle are not fixed. This causes the mass and position of the vehicle's center of mass to constantly change. The vehicle needs to resolve the contradiction between smoothness and stability during driving. What is most needed is the center of mass position of the entire vehicle to assist the ECU in calculating and adjusting the damping of each CDC shock absorber. The determination of the mass and position of the center of mass can provide certain support for improving the vehicle smoothness of semi-active suspension vehicles. The current determination method generally cannot measure dynamically, or the dynamic measurement of the center of mass is inaccurate, resulting in poor suspension response, or too many sensors are used, resulting in high costs, and too many calculations are incorporated into the height change of the center of mass. The main condition that really affects smoothness is the change in the center of mass on the plane of the entire vehicle, thereby changing the force loaded on the CDC shock absorber. Summary of the invention

[0003] The purpose of the present invention is to solve the problems that the existing determination methods are generally unable to perform dynamic measurement, or the dynamic measurement of the center of mass is inaccurate resulting in poor suspension response, or the use of too many sensors leads to high costs, and proposes a method for locating the center of mass of the entire vehicle.

[0004] The problem to be solved by the present invention is achieved by the following technical solutions:

[0005] A method for locating the center point of mass of a whole vehicle plane, comprising:

[0006] Step S1, inflate the tires of the test vehicle to the standard tire pressure of the vehicle under the corresponding load state, cover the four wheel load meters with white paper, evenly apply black paint on the wheels, and lift the vehicle to the top of the wheel load meter;

[0007] Step S2, slowly lower the vehicle to the wheel load meter, the wheel load meter records the pressure values ​​of the four wheels and then lifts the vehicle, uses a camera to take pictures of each time the tire paint contacts the paper, obtains the contact area on the paper in the picture in the camera, and obtains the corresponding relationship between the contact area of ​​each wheel tire and the ground and the pressure of a certain wheel position acting on the ground through the tire in real time;

[0008] Step S3, installing an environmental chamber around the wheel load meter, repeating steps S1 and S2 to determine the data of the pressure compensation coefficient changing with temperature, and determining the pressure compensation coefficient according to the data of the pressure compensation coefficient changing with temperature;

[0009] Step S4, determining the real pressure value of each wheel point after removing the temperature influence according to the pressure compensation coefficient;

[0010] Step S5, obtaining the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, and center of mass of the right front wheel point and the left rear wheel point of the test vehicle, and determining the coordinate data of the planar mass center point of the whole vehicle according to the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, center of mass of the right front wheel point and the left rear wheel point of the test vehicle and the real pressure values ​​of each wheel point after removing the temperature influence.

[0011] Preferably, the corresponding load states include: no-load state, half-load state and full-load state.

[0012] Preferably, in step S1, a camera is used to take pictures of the images printed on the paper each time the tire paint contacts the paper at an interval of 0.5 KN.

[0013] Preferably, the pressure compensation coefficient in step S3 is as shown in formula (1):

[0014]

[0015] Wherein: β is the pressure compensation coefficient, P1 is the standard tire pressure, S1 is the contact area between the tire and the ground under the standard tire pressure, F2 is the mass of a certain wheel position of the vehicle after curb weight, P2 is the tire pressure after temperature change, S2 is the contact area between the tire and the ground after load and temperature change, α is the expansion coefficient of tire pressure with temperature change, ΔC is the temperature change difference.

[0016] Preferably, the real pressure value of each wheel point after removing the temperature effect includes: the real pressure value of the left front wheel point after removing the temperature effect, the real pressure value of the left rear wheel point after removing the temperature effect,

[0017] The true pressure value of the right front wheel point after removing the temperature influence and the true pressure value of the right rear wheel point after removing the temperature influence.

[0018] Preferably, the real pressure value of the left front wheel point after removing the temperature influence is as shown in formula (2):

[0019]

[0020] Where: Fa is the true pressure value of the left front wheel point after removing the temperature influence, F2a is the tread mass of the left front wheel position, P2a is the tire pressure after the left front wheel temperature changes, S2a is the tire contact area with the ground after the left front wheel load and temperature changes, β is the pressure compensation coefficient;

[0021] The actual pressure value of the right front wheel point after removing the temperature influence is as shown in formula (3):

[0022]

[0023] Among them: Fb is the real pressure value of the right front wheel point after removing the temperature influence, F2b is the curb weight of the right front wheel position, P2b is the tire pressure after the temperature of the right front wheel changes, S2b is the contact area between the tire and the ground after the load and temperature of the right front wheel changes, and β is the pressure compensation coefficient.

[0024] Preferably, the real pressure value of the left rear wheel point after removing the temperature influence is as shown in formula (4):

[0025]

[0026] Where: Fc is the true pressure value of the left rear wheel point after removing the temperature influence, F2c is the tread mass of the left rear wheel position, P2c is the tire pressure after the left rear wheel temperature changes, S2c is the tire contact area with the ground after the left rear wheel load and temperature changes, β is the pressure compensation coefficient;

[0027] The actual pressure value of the right rear wheel point after removing the temperature influence is as shown in formula (5):

[0028]

[0029] Among them: Fd is the real pressure value of the right rear wheel point after removing the temperature influence, F2d is the curb weight of the right rear wheel position, P2d is the tire pressure after the temperature of the right rear wheel changes, S2d is the contact area between the tire and the ground after the load and temperature of the right rear wheel changes, and β is the pressure compensation coefficient.

[0030] Preferably, the method of determining the coordinate data of the center point of mass of the whole vehicle plane according to the coaxial wheelbase, wheelbase, the center of mass of the left front wheel point and the right rear wheel point, the center of mass of the right front wheel point and the left rear wheel point, and the real pressure value of each wheel point after removing the temperature effect includes:

[0031] Determine the angles between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively according to the coaxial wheelbase and wheelbase of the test vehicle;

[0032] Determine the distance between the center of mass of the left front wheel point and the right rear wheel point and the center of mass of the right front wheel point and the left rear wheel point according to the center of mass of the left front wheel point and the right rear wheel point and the center of mass of the right front wheel point and the left rear wheel point;

[0033] Determine the real pressure value of the center of mass of the left front wheel point and the right rear wheel point without the influence of temperature according to the real pressure value of the left front wheel point without the influence of temperature and the real pressure value of the right rear wheel point without the influence of temperature;

[0034] Determine the real pressure value of the center of mass of the right front wheel point and the left rear wheel point without the influence of temperature according to the real pressure value of the right front wheel point without the influence of temperature and the real pressure value of the left rear wheel point without the influence of temperature;

[0035] The distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point is determined according to formula (6) based on the distance between the center of mass of the left front wheel point and the right rear wheel point and the line connecting the center of mass of the right front wheel point and the left rear wheel point, the real pressure value of the center of mass of the left front wheel point and the right rear wheel point without the influence of temperature, and the real pressure value of the center of mass of the right front wheel point and the left rear wheel point without the influence of temperature:

[0036] s7= Ff·s8 / Fe (6)

[0037] Wherein: s7 is the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel and the right rear wheel, Ff is the real pressure value of the center of mass of the right front wheel and the left rear wheel after removing the temperature influence, s8 is the distance between the center of mass of the left front wheel and the right rear wheel and the center of mass of the right front wheel and the left rear wheel, Fe is the real pressure value of the center of mass of the left front wheel and the right rear wheel after removing the temperature influence;

[0038] Determine the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle according to the distance between the center of mass of the left front wheel point and the right rear wheel point and the line connecting the center of mass of the right front wheel point and the left rear wheel point and the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point;

[0039] The coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the line connecting the center point of mass of the left front wheel point and the right rear wheel point and the left front wheel point, and the wheelbase of the test vehicle. The coordinate data of the center point of the plane mass of the whole vehicle includes: the horizontal coordinate data of the center point of the plane mass of the whole vehicle and the vertical coordinate data of the center point of the plane mass of the whole vehicle.

[0040] Preferably, the coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the center point of mass of the left front wheel point and the right rear wheel point and the connecting line of the left front wheel point and the wheelbase of the test vehicle, including:

[0041] When the coordinate data of the center point of the plane mass of the whole vehicle is the horizontal coordinate data of the center point of the plane mass of the whole vehicle:

[0042] The distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center of mass of the right front wheel point and the left rear wheel point and the connecting line of the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, the wheelbase of the test vehicle and the connecting line distance of the center of mass of the left rear wheel point and the right front wheel point and the left rear wheel point are determined by formula (7):

[0043]

[0044] Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the real pressure value of the right front wheel point after removing the temperature effect, Fd is the real pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle, S7 is the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

[0045] Preferably, the coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the center point of mass of the left front wheel point and the right rear wheel point and the connecting line of the left front wheel point and the wheelbase of the test vehicle, including:

[0046] When the coordinate data of the center point of the plane mass of the whole vehicle is the vertical coordinate data of the center point of the plane mass of the whole vehicle:

[0047] The distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center of mass of the right front wheel point and the left rear wheel point and the connecting line of the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, the wheelbase of the test vehicle and the connecting line distance of the center of mass of the left rear wheel point and the right front wheel point and the left rear wheel point are determined by formula (7):

[0048]

[0049] Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the true pressure value of the right front wheel point after removing the temperature effect, Fd is the true pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, s7 is the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

[0050] The present invention has the following beneficial effects compared with the prior art:

[0051] The present invention discloses a method for locating the center point of the plane mass of a whole vehicle. By calculating the pressure compensation coefficient β, the influence of the pressure change caused by the temperature change is removed. Under the conditions of room temperature 25°C and standard tire pressure 2.5 bar, the corresponding relationship between the contact area between each wheel tire and the ground and the pressure of a certain wheel position acting on the ground through the tire in real time is obtained. The mass of the center point of the plane mass of the whole vehicle and the horizontal and vertical coordinates of the center of mass of the vehicle on the same horizontal plane relative to the left front wheel point a are obtained through the balance principle between force and lever arm. The present invention can obtain the mass and position of the center point of the plane mass of the whole vehicle in real time and accurately during the driving process of the vehicle, provide algorithm support for the vehicle suspension ECU, and expand the application field of semi-active suspension. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The present invention is a flow chart of a method for locating the center point of mass of a whole vehicle plane.

[0053] Figure 2 The present invention discloses a graph showing the change of pressure compensation coefficient with temperature in a method for locating the center point of plane mass of a whole vehicle.

[0054] Figure 3 It is a corresponding relationship diagram in a method for locating the plane mass center point of a whole vehicle according to the present invention.

[0055] Figure 4 The invention discloses a point distribution diagram of a method for locating the center point of the plane mass of a whole vehicle. DETAILED DESCRIPTION

[0056] The following is based on the attached Figure 1-4 The present invention is further described:

[0057] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] like Figure 1 As shown, the first embodiment of the present invention provides a method for locating the center of mass of a vehicle plane based on the prior art, comprising:

[0061] Step S1, inflate the tires of the test vehicle to the standard tire pressure of the vehicle under the corresponding load state, cover the four wheel load meters with white paper, evenly apply black paint on the wheels, and lift the vehicle to the top of the wheel load meter.

[0062] The corresponding load states include: no-load state, half-load state and full-load state. The load is 75kg standard water man, 5kg, 10kg, 25kg standard sandbags are used for half-load and full-load counterweights. In this embodiment, a 5-ton crane and a vehicle hoist are used to lift the test vehicle and repeatedly lift the test vehicle during the test to achieve the effect of gradually increasing the pressure on the wheel load meter. White paper is used to lay on the wheel load meter and contact with the tire to obtain the contact area. The size of the paper must exceed the maximum cross-sectional plane area formed by the wheel in the XY direction to ensure that the wheel mark will not cover the outside of the paper.

[0063] Step S2, slowly lower the vehicle to the wheel load meter, the wheel load meter records the pressure values ​​of the four wheels and then lifts the vehicle, uses a camera to take pictures of the pictures printed on the paper each time the tire paint contacts the paper, obtains the contact area on the paper in the picture in the camera, and obtains the corresponding relationship between the contact area between each wheel tire and the ground and the pressure exerted on the ground by the tire in real time at a certain wheel position.

[0064] The above camera is used to take pictures of the black pigment of the tire covering the white paper after it contacts the paper at intervals of 0.5KN. The shooting height and angle should be fixed each time. The contact area on the paper in the picture in the camera is obtained by executing the corresponding recognition software on the computer. The corresponding relationship between the contact area of ​​each wheel tire and the ground and the pressure exerted on the ground by the tire at a certain wheel position in real time is as follows: Figure 3 shown.

[0065] Step S3, installing an environmental chamber around the wheel load meter, repeating steps S1 and S2 to determine the data of the pressure compensation coefficient changing with temperature, and determining the pressure compensation coefficient according to the data of the pressure compensation coefficient changing with temperature.

[0066] The pressure compensation coefficient changes with temperature as shown in the following figure: Figure 2 As shown, when the temperature rises, the force caused by the decrease in temperature change should be compensated, and when the temperature drops, the force caused by the increase in temperature change should be removed. The pressure compensation coefficient is shown in formula (1):

[0067]

[0068] Wherein: β is the pressure compensation coefficient, P1 is the standard tire pressure, S1 is the contact area between the tire and the ground under the standard tire pressure, F2 is the mass of a certain wheel position of the vehicle after curb weight, P2 is the tire pressure after temperature change, S2 is the contact area between the tire and the ground after load and temperature change, α is the expansion coefficient of tire pressure with temperature change, ΔC is the temperature change difference.

[0069] Step S4, determining the real pressure value of each wheel point after removing the temperature influence according to the pressure compensation coefficient.

[0070] The real pressure value of each wheel point after removing the temperature influence includes: the real pressure value of the left front wheel point after removing the temperature influence, the real pressure value of the left rear wheel point after removing the temperature influence, the real pressure value of the right front wheel point after removing the temperature influence and the real pressure value of the right rear wheel point after removing the temperature influence.

[0071] The actual pressure value of the left front wheel point after removing the temperature effect is shown in formula (2):

[0072]

[0073] Where: Fa is the true pressure value of the left front wheel point after removing the temperature influence, F2a is the tread mass of the left front wheel position, P2a is the tire pressure after the left front wheel temperature changes, S2a is the tire contact area with the ground after the left front wheel load and temperature changes, β is the pressure compensation coefficient;

[0074] The actual pressure value of the right front wheel point after removing the temperature effect is shown in formula (3):

[0075]

[0076] Among them: Fb is the real pressure value of the right front wheel point after removing the temperature influence, F2b is the curb weight of the right front wheel position, P2b is the tire pressure after the temperature of the right front wheel changes, S2b is the contact area between the tire and the ground after the load and temperature of the right front wheel changes, and β is the pressure compensation coefficient.

[0077] The actual pressure value of the left rear wheel point after removing the temperature effect is shown in formula (4):

[0078]

[0079] Where: Fc is the true pressure value of the left rear wheel point after removing the temperature influence, F2c is the tread mass of the left rear wheel position, P2c is the tire pressure after the left rear wheel temperature changes, S2c is the tire contact area with the ground after the left rear wheel load and temperature changes, β is the pressure compensation coefficient;

[0080] The actual pressure value of the right rear wheel point after removing the temperature effect is shown in formula (5):

[0081]

[0082] Among them: Fd is the real pressure value of the right rear wheel point after removing the temperature influence, F2d is the curb weight of the right rear wheel position, P2d is the tire pressure after the temperature of the right rear wheel changes, S2d is the contact area between the tire and the ground after the load and temperature of the right rear wheel changes, and β is the pressure compensation coefficient.

[0083] Step S5, obtaining the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, and center of mass of the right front wheel point and the left rear wheel point of the test vehicle, and determining the coordinate data of the planar mass center point of the whole vehicle according to the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, center of mass of the right front wheel point and the left rear wheel point of the test vehicle and the real pressure values ​​of each wheel point after removing the temperature influence.

[0084] like Figure 4 As shown, the left front wheel point is a, the right front wheel point is b, the left rear wheel point is c, the right rear wheel point is d, Lab = Lcd is the wheelbase, Lad = Lbc is the wheelbase, and the angle r between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point is determined according to the coaxial wheelbase and wheelbase of the test vehicle;

[0085] Determine the distance s8 between the centroid point e of the left front wheel point a and the right rear wheel point c and the centroid point f of the right front wheel point b and the left rear wheel point d according to the centroid point e of the left front wheel point a and the right rear wheel point c and the centroid point f of the right front wheel point b and the left rear wheel point d;

[0086] According to the real pressure value Fa of the left front wheel point a without the influence of temperature and the real pressure value Fc of the right rear wheel point c without the influence of temperature, the real pressure value Fe of the center of mass of the left front wheel point a and the right rear wheel point c without the influence of temperature is determined as Fe=(Fa+Fc) / 2;

[0087] Determine the real pressure value Ff=(Fb+Fd) / 2 of the centroid of the right front wheel point b and the left rear wheel point d without the influence of temperature according to the real pressure value Fb of the right front wheel point b without the influence of temperature and the real pressure value Fd of the left rear wheel point d without the influence of temperature;

[0088] According to the distance s8 between the mass center point e of the left front wheel point a and the right rear wheel point c and the mass center point f of the right front wheel point b and the left rear wheel point d, the real pressure value Fe of the mass center point e of the left front wheel point a and the right rear wheel point c without the temperature effect, and the real pressure value Ff of the mass center point f of the right front wheel point b and the left rear wheel point d without the temperature effect, the distance s7 between the center point h of the whole vehicle plane mass and the mass center point e of the left front wheel point a and the right rear wheel point c is determined according to formula (6):

[0089] s7= Ff·s8 / Fe (6)

[0090] Wherein: s7 is the distance between the center of mass of the whole vehicle h and the center of mass e of the left front wheel point a and the right rear wheel point c, Ff is the real pressure value of the center of mass of the right front wheel point b and the left rear wheel point d after removing the temperature influence, s8 is the distance between the center of mass of the left front wheel point a and the right rear wheel point c and the center of mass of the right front wheel point b and the left rear wheel point d, Fe is the real pressure value of the center of mass of the left front wheel point a and the right rear wheel point c after removing the temperature influence;

[0091] Determine the distance s6 between the mass center point f of the right front wheel point b and the left rear wheel point d and the whole vehicle plane mass center point h according to the distance s8 between the mass center point e of the left front wheel point a and the right rear wheel point c and the mass center point f of the right front wheel point b and the left rear wheel point d and the distance s7 between the whole vehicle plane mass center point h and the mass center point e of the left front wheel point a and the right rear wheel point c;

[0092] The coordinate data of the vehicle's plane mass center point h is determined based on the distance s6 between the center of mass point f of the right front wheel point b and the left rear wheel point d and the vehicle's plane mass center point h, the distance s7 between the vehicle's plane mass center point h and the center of mass point e of the left front wheel point a and the right rear wheel point c, the real pressure value Fb of the right front wheel point b after removing the temperature effect, the real pressure value Fd of the left rear wheel point d after removing the temperature effect, the angle r° between the left front wheel point a and the lines connecting the left rear wheel point d and the right rear wheel point c, the distance Ldf between the center of mass point f of the right front wheel point b and the left rear wheel point d and the left rear wheel point d, the distance Lae between the line connecting the center of mass point e of the left front wheel point a and the right rear wheel point c and the left front wheel point a, and the wheelbase Lad of the test vehicle. The coordinate data of the vehicle's plane mass center point h includes: the horizontal coordinate data of the vehicle's plane mass center point and the vertical coordinate data of the vehicle's plane mass center point.

[0093] When the coordinate data of the center point of the vehicle's plane mass is the horizontal coordinate data of the center point of the vehicle's plane mass:

[0094] The horizontal coordinate data of the center point of the vehicle's plane mass is determined by formula (7):

[0095]

[0096] Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the real pressure value of the right front wheel point after removing the temperature effect, Fd is the real pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle, S7 is the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

[0097] When the coordinate data of the center point of the vehicle's plane mass is the vertical coordinate data of the center point of the vehicle's plane mass:

[0098] The horizontal coordinate data of the center point of the vehicle's plane mass is determined by formula (8):

[0099]

[0100] Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the true pressure value of the right front wheel point after removing the temperature effect, Fd is the true pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, s7 is the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

[0101] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A method for locating the center point of mass of a vehicle plane, characterized in that: include: Step S1, inflate the tires of the test vehicle to the standard tire pressure of the vehicle under the corresponding load state, cover the four wheel load meters with white paper, evenly apply black paint on the wheels, and lift the vehicle to the top of the wheel load meter; Step S2, slowly lower the vehicle to the wheel load meter, the wheel load meter records the pressure values ​​of the four wheels and then lifts the vehicle, uses a camera to take pictures of each time the tire paint contacts the paper, obtains the contact area on the paper in the picture in the camera, and obtains the corresponding relationship between the contact area of ​​each wheel tire and the ground and the pressure of a certain wheel position acting on the ground through the tire in real time; Step S3, installing an environmental chamber around the wheel load meter, repeating steps S1 and S2 to determine the data of the pressure compensation coefficient changing with temperature, and determining the pressure compensation coefficient according to the data of the pressure compensation coefficient changing with temperature; Step S4, determining the real pressure value of each wheel point after removing the temperature influence according to the pressure compensation coefficient; Step S5, obtaining the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, and center of mass of the right front wheel point and the left rear wheel point of the test vehicle, and determining the coordinate data of the planar mass center point of the whole vehicle according to the coaxial wheelbase, wheelbase, center of mass of the left front wheel point and the right rear wheel point, center of mass of the right front wheel point and the left rear wheel point of the test vehicle and the real pressure values ​​of each wheel point after removing the temperature influence.

2. A method for locating the center of mass of a vehicle plane according to claim 1, characterized in that: The corresponding load states include: no-load state, half-load state and full-load state.

3. A method for locating the center of mass of a vehicle plane according to claim 1, characterized in that: In the step S1, a camera is used to take pictures of the images printed on the paper each time the tire paint contacts the paper at an interval of 0.5 KN.

4. A method for locating the center of mass of a vehicle plane according to claim 1, characterized in that: The pressure compensation coefficient in step S3 is shown in formula (1): Wherein: β is the pressure compensation coefficient, P1 is the standard tire pressure, S1 is the contact area between the tire and the ground under the standard tire pressure, F2 is the mass of a certain wheel position of the vehicle after curb weight, P2 is the tire pressure after temperature change, S2 is the contact area between the tire and the ground after load and temperature change, α is the expansion coefficient of tire pressure with temperature change, ΔC is the temperature change difference.

5. The method for locating the center of mass of a vehicle plane according to claim 1, characterized in that: The real pressure value of each wheel point after removing the temperature effect includes: the real pressure value of the left front wheel point after removing the temperature effect, the real pressure value of the left rear wheel point after removing the temperature effect, The true pressure value of the right front wheel point after removing the temperature influence and the true pressure value of the right rear wheel point after removing the temperature influence.

6. A method for locating the center of mass of a vehicle plane according to claim 5, characterized in that: The actual pressure value of the left front wheel point after removing the temperature influence is as shown in formula (2): Where: Fa is the true pressure value of the left front wheel point after removing the temperature influence, F2a is the tread mass of the left front wheel position, P2a is the tire pressure after the left front wheel temperature changes, S2a is the tire contact area with the ground after the left front wheel load and temperature changes, β is the pressure compensation coefficient; The actual pressure value of the right front wheel point after removing the temperature influence is as shown in formula (3): Among them: Fb is the real pressure value of the right front wheel point after removing the temperature influence, F2b is the curb weight of the right front wheel position, P2b is the tire pressure after the temperature of the right front wheel changes, S2b is the contact area between the tire and the ground after the load and temperature of the right front wheel changes, and β is the pressure compensation coefficient.

7. A method for locating the center of mass of a vehicle plane according to claim 5, characterized in that: The actual pressure value of the left rear wheel point after removing the temperature influence is as shown in formula (4): Where: Fc is the true pressure value of the left rear wheel point after removing the temperature influence, F2c is the tread mass of the left rear wheel position, P2c is the tire pressure after the left rear wheel temperature changes, S2c is the tire contact area with the ground after the left rear wheel load and temperature changes, β is the pressure compensation coefficient; The actual pressure value of the right rear wheel point after removing the temperature influence is as shown in formula (5): Among them: Fd is the real pressure value of the right rear wheel point after removing the temperature influence, F2d is the curb weight of the right rear wheel position, P2d is the tire pressure after the temperature of the right rear wheel changes, S2d is the contact area between the tire and the ground after the load and temperature of the right rear wheel changes, and β is the pressure compensation coefficient.

8. A method for locating the center of mass of a vehicle plane according to claim 5, characterized in that: The method of determining the coordinate data of the center point of the plane mass of the whole vehicle according to the coaxial wheelbase, wheelbase, the center of mass of the left front wheel point and the right rear wheel point, the center of mass of the right front wheel point and the left rear wheel point, and the real pressure value of each wheel point after removing the temperature effect includes: Determine the angles between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively according to the coaxial wheel track and wheelbase of the test vehicle; Determine the distance between the center of mass of the left front wheel point and the right rear wheel point and the center of mass of the right front wheel point and the left rear wheel point according to the center of mass of the left front wheel point and the right rear wheel point and the center of mass of the right front wheel point and the left rear wheel point; Determine the real pressure value of the center of mass of the left front wheel point and the right rear wheel point without the influence of temperature according to the real pressure value of the left front wheel point without the influence of temperature and the real pressure value of the right rear wheel point without the influence of temperature; Determine the real pressure value of the center of mass of the right front wheel point and the left rear wheel point without the influence of temperature according to the real pressure value of the right front wheel point without the influence of temperature and the real pressure value of the left rear wheel point without the influence of temperature; The distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point is determined according to formula (6) based on the distance between the center of mass of the left front wheel point and the right rear wheel point and the line connecting the center of mass of the right front wheel point and the left rear wheel point, the real pressure value of the center of mass of the left front wheel point and the right rear wheel point without the influence of temperature, and the real pressure value of the center of mass of the right front wheel point and the left rear wheel point without the influence of temperature: s7= Ff·s8 / Fe (6) Wherein: s7 is the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel and the right rear wheel, Ff is the real pressure value of the center of mass of the right front wheel and the left rear wheel after removing the temperature influence, s8 is the distance between the center of mass of the left front wheel and the right rear wheel and the center of mass of the right front wheel and the left rear wheel, Fe is the real pressure value of the center of mass of the left front wheel and the right rear wheel after removing the temperature influence; Determine the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle according to the distance between the center of mass of the left front wheel point and the right rear wheel point and the line connecting the center of mass of the right front wheel point and the left rear wheel point and the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point; The coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the line connecting the center point of mass of the left front wheel point and the right rear wheel point and the left front wheel point, and the wheelbase of the test vehicle. The coordinate data of the center point of the plane mass of the whole vehicle includes: the horizontal coordinate data of the center point of the plane mass of the whole vehicle and the vertical coordinate data of the center point of the plane mass of the whole vehicle.

9. A method for locating the center of mass of a vehicle plane according to claim 8, characterized in that: The coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the connecting line of the center point of mass of the left front wheel point and the right rear wheel point and the left front wheel point, and the wheelbase of the test vehicle, including: When the coordinate data of the center point of the plane mass of the whole vehicle is the horizontal coordinate data of the center point of the plane mass of the whole vehicle: The distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center of mass of the right front wheel point and the left rear wheel point and the connecting line of the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, the wheelbase of the test vehicle and the connecting line distance of the center of mass of the left rear wheel point and the right front wheel point and the left rear wheel point are determined by formula (7): Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the real pressure value of the right front wheel point after removing the temperature effect, Fd is the real pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle, S7 is the distance between the center of mass of the whole vehicle and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

10. A method for locating the center of mass of a vehicle plane according to claim 8, characterized in that: The coordinate data of the center point of the plane mass of the whole vehicle is determined according to the distance between the center point of mass of the right front wheel point and the left rear wheel point and the center point of the plane mass of the whole vehicle, the distance between the center point of the plane mass of the whole vehicle and the center points of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center point of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, the distance between the connecting line of the center point of mass of the left front wheel point and the right rear wheel point and the left front wheel point, and the wheelbase of the test vehicle, including: When the coordinate data of the center point of the plane mass of the whole vehicle is the vertical coordinate data of the center point of the plane mass of the whole vehicle: The distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, the real pressure value of the right front wheel point after removing the influence of temperature, the real pressure value of the left rear wheel point after removing the influence of temperature, the angle between the left front wheel point and the connecting line of the left rear wheel point and the right rear wheel point, the distance between the center of mass of the right front wheel point and the left rear wheel point and the connecting line of the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, the wheelbase of the test vehicle and the connecting line distance of the center of mass of the left rear wheel point and the right front wheel point and the left rear wheel point are determined by formula (8): Among them: r is the angle between the left front wheel point and the lines connecting the left rear wheel point and the right rear wheel point respectively, Lae is the distance between the center of mass of the left front wheel point and the right rear wheel point and the left front wheel point, Ldf is the distance between the center of mass of the right front wheel point and the left rear wheel point and the left rear wheel point, Fb is the true pressure value of the right front wheel point after removing the temperature effect, Fd is the true pressure value of the right rear wheel point after removing the temperature effect, s6 is the distance between the center of mass of the right front wheel point and the left rear wheel point and the center of mass of the whole vehicle plane, s7 is the distance between the center of mass of the whole vehicle plane and the center of mass of the left front wheel point and the right rear wheel point, and Lad is the wheelbase of the test vehicle.

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