阅读说明：本技术 一种牵引挂车质心位置的获取方法及获取系统 (Method and system for acquiring center of mass position of towing trailer ) 是由 刘源 于 2020-11-25 设计创作，主要内容包括：本发明涉及一种牵引挂车质心位置的获取方法及获取系统,所述获取方法根据货物质心、车头质心坐标、挂车质心坐标以及车头与挂车之间的夹角θ实时获取全车质心的坐标。无论牵引挂车处于直行状态还是转弯状态,该获取方法针对全车质心的位置均能够实时获取,这就给车辆操纵和控制提供了准确的参数,从而增强了车辆行驶的稳定性和安全性。(The invention relates to a method and a system for acquiring the centroid position of a towing trailer. No matter the towed trailer is in a straight-going state or a turning state, the position of the center of mass of the whole trailer can be obtained in real time by the obtaining method, so that accurate parameters are provided for vehicle operation and control, and the driving stability and safety of the vehicle are enhanced.)

1. The method for acquiring the mass center position of the towed trailer is applied by combining a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system takes the projection of a hitching point of the trailer and a vehicle head on the ground as an origin, the advancing direction of the vehicle head is an X-axis forward direction, the left side of the vehicle head is a Y-axis forward direction, and the vertically upward direction is a Z-axis forward direction, and is characterized by comprising the following steps of:

obtaining the coordinates (x) of the center of mass of the goods when the included angle between the head and the trailer is 0 degree_c，y_c，z_c)；

According to vehicle design parameters, a vehicle head mass center coordinate (x) is obtained when the included angle between the vehicle head and the trailer is 0 degree_a，y_a，z_a) And trailer centroid coordinates (x)_b，y_b，z_b) When the included angle between the head of the vehicle and the trailer is theta, the real-time coordinate of the mass center of the whole vehicle is (x)_m，y_m，z_m) And, and:

wherein m is_aM is the weight of the vehicle head_bFor trailer mass, m_cIs the cargo quality.

2. The obtaining method according to claim 1, wherein the obtaining of the coordinates of the center of mass of the cargo when the included angle between the vehicle head and the trailer is 0 ° specifically comprises:

obtaining the pressure F applied to the trailer by the front end of the goods in a static state_fPressure F applied to the trailer by the rear end of the cargo_bPressure F applied to the trailer on the left side of the cargo_lAnd the pressure F applied to the trailer by the right side of the cargo_r；

Acquiring the pressure F applied to the trailer by the front end of the cargo when the acceleration is a_f', pressure F applied to the trailer at the rear end of the cargo_b’；

Wherein, F_fAnd F_bThe longitudinal distance between the acquisition positions is l; origin and F_fIs longitudinally spaced by a distance l₀(ii) a Center of mass of cargo and F_fHas a longitudinal spacing of l₁；F_lAnd F_rThe lateral spacing between the acquisition positions of (a) is b; center of mass of cargo and F_lHas a lateral spacing of b₁；F_fIs at a vertical spacing z from the ground₀(ii) a Center of mass of cargo and F_fIs at a vertical spacing z₁；

And the number of the first and second electrodes,

x_c＝-(l₀+l₁)，y_c＝b/2-b₁；z_c＝z₀+z₁。

3. method for obtaining according to claim 2, characterized in that the pressure force F is obtained from the front left-end corner of the goods₁Taking the pressure F from the front right corner of the cargo₂Taking the pressure F from the rear left end corner of the cargo₃Obtaining pressure F from the rear right end corner of the goods₄Wherein F is₁+F₂＝F_f，F₃+F₄＝F_b，F₁+F₃＝F_l，F₂+F₄＝F_r。

4. The utility model provides a pull acquisition system of trailer barycenter position, combines three-dimensional rectangular coordinate system to use, wherein, three-dimensional rectangular coordinate system uses the trailer with the projection on ground of the point of hanging of locomotive as the initial point, and the advancing direction of locomotive is the X axle forward, and the left side of locomotive is the Y axle forward, and vertical ascending direction is the Z axle forward, its characterized in that, acquisition system includes:

the angle sensor (5) is used for detecting an included angle between the vehicle head and the trailer;

a cargo mass center obtaining subsystem for obtaining the coordinates (x) of the cargo mass center when the included angle between the trailer and the trailer is 0 degree_c，y_c，z_c)；

The vehicle head mass center acquisition module is used for acquiring a vehicle head mass center coordinate (x) when the included angle between the vehicle head and the trailer is 0 degree according to vehicle design parameters_a，y_a，z_a)；

The trailer mass center acquisition module is used for acquiring trailer mass center coordinates (x) when the included angle between the trailer head and the trailer is 0 degree according to vehicle design parameters_b，y_b，z_b)；

The whole vehicle mass center obtaining module is used for obtaining the included angle between the vehicle head and the trailer according to the formula when the included angle is theta:

and

the real-time coordinate of the center of mass of the whole vehicle is obtained by calculation as (x)_m，y_m，z_m) Wherein m is_aM is the weight of the vehicle head_bFor trailer mass, m_cIs the cargo quality.

5. The acquisition system of claim 4 wherein the cargo centroid acquisition subsystem comprises:

an acceleration sensor (6) for measuring the acceleration of the tractor trailer;

a front end pressure sensor for acquiring the pressure F applied to the trailer by the front end of the cargo in the static state of the trailer_fWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the front end of the cargo is obtained_f’；

A rear end pressure sensor for acquiring the pressure F applied to the trailer by the rear end of the goods in the static state of the trailer_bWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the rear end of the cargo is obtained_b’；

A left side pressure sensor for acquiring the pressure F applied to the trailer by the left side of the goods in the static state of the trailer_l；

A right side pressure sensor for acquiring the pressure F applied to the trailer by the right side of the cargo in the static state of the trailer_r；

A cargo centroid acquisition module for: ,

x_c＝-(l₀+l₁)，y_c＝b/2-b₁；z_c＝z₀+z₁calculating to obtain coordinates (x) of the center of mass of the goods_c，y_c，z_c)；

Wherein the longitudinal distance between the front end pressure sensor and the rear end pressure sensor is l; the longitudinal distance between the origin and the left pressure sensor is l₀(ii) a The longitudinal distance between the center of mass of the cargo and the left pressure sensor is l₁(ii) a Between the left side pressure sensor and the right side pressure sensorThe transverse distance between the two is b; the transverse distance between the center of mass of the cargo and the left pressure sensor is b₁(ii) a The vertical distance between the left pressure sensor and the ground is z₀(ii) a The vertical distance between the center of mass of the cargo and the left pressure sensor is z₁。

6. The acquisition system according to claim 5, characterized in that a first pressure sensor (1) is arranged between the left front corner of the cargo and the trailer, a second pressure sensor (2) is arranged between the right front corner of the cargo and the trailer, a third pressure sensor (3) is arranged between the left rear corner of the cargo and the trailer, and a fourth pressure sensor (4) is arranged between the right rear corner of the cargo and the trailer;

wherein the first pressure sensor (1) and the second pressure sensor (2) constitute the front end pressure sensor; the third pressure sensor (3) and the fourth pressure sensor (4) constitute the rear end pressure sensor; the first pressure sensor (1) and the third pressure sensor (3) constitute the left side pressure sensor; the second pressure sensor (2) and the fourth pressure sensor (4) constitute the right-side pressure sensor.

7. The acquisition system according to claim 6, characterized in that the vehicle head centroid acquisition module, the trailer centroid acquisition module, the whole vehicle centroid acquisition module and the cargo centroid acquisition module are integrated into a control unit (7).

Technical Field

The invention relates to the technical field of vehicle parameter acquisition, in particular to a method and a system for acquiring the centroid position of a towing trailer.

Background

The position of the center of mass of the vehicle is one of important performance parameters of the vehicle, is closely related to the safety, the controllability and the stability of the vehicle, and has very important significance in accurately measuring the center of mass of the vehicle.

The method for obtaining the center of mass of the vehicle generally comprises static measurement and dynamic measurement, however, the current static measurement and dynamic measurement are directed to non-trailer vehicles, and for trailer vehicles and vehicles with non-rigid connection of the head and the body, the position of the center of mass of the trailer whole will be changed significantly after loading cargo, and the center of mass of the vehicle will be changed at any moment during the turning process of the trailer, although the center of mass of the head and the center of mass of the trailer are known at the time of design, but the dynamic measurement of the center of mass of the trailer is very difficult due to the uncertainty of the center of mass of the cargo.

Therefore, it is an urgent technical problem to be solved by those skilled in the art to provide a method for acquiring the centroid position of a towed trailer to ensure the handling stability and safety of the vehicle.

Disclosure of Invention

One of the purposes of the invention is to provide a method for acquiring the position of the center of mass of a towing trailer so as to ensure the operation stability and the safety of the towing trailer.

Another object of the present invention is to provide a system for acquiring the position of the center of mass of a tractor trailer.

In order to achieve the above object, the method for acquiring the centroid position of a towed trailer provided by the present invention is applied by combining a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system uses the projection of the hitching point of the trailer and the vehicle head on the ground as an origin, the forward direction of the vehicle head is the X-axis forward direction, the left side of the vehicle head is the Y-axis forward direction, and the vertically upward direction is the Z-axis forward direction, and the method comprises:

obtaining the coordinates (x) of the center of mass of the goods when the included angle between the head and the trailer is 0 degree_c，y_c，z_c)；

According to vehicle design parameters, a vehicle head mass center coordinate (x) is obtained when the included angle between the vehicle head and the trailer is 0 degree_a，y_a，z_a) And trailer centroid coordinates (x)_b，yb，z_b) When the included angle between the head of the vehicle and the trailer is theta, the real-time coordinate of the mass center of the whole vehicle is (x)_m，y_m，z_m) And, and:

wherein m is_aAs quality of the vehicle head，m_bFor trailer mass, m_cIs the cargo quality.

Preferably, in the obtaining method, the obtaining of the coordinates of the center of mass of the cargo when the included angle between the vehicle head and the trailer is 0 ° specifically includes:

obtaining the pressure F applied to the trailer by the front end of the goods in a static state_fPressure F applied to the trailer by the rear end of the cargo_bPressure F applied to the trailer on the left side of the cargo_lAnd the pressure F applied to the trailer by the right side of the cargo_r；

Acquiring the pressure F applied to the trailer by the front end of the cargo when the acceleration is a_f', pressure F applied to the trailer at the rear end of the cargo_b’；

Wherein, F_fAnd F_bThe longitudinal distance between the acquisition positions is l; origin and F_fIs longitudinally spaced by a distance l₀(ii) a Center of mass of cargo and F_fHas a longitudinal spacing of l₁；F_lAnd F_rThe lateral spacing between the acquisition positions of (a) is b; center of mass of cargo and F_lHas a lateral spacing of b₁；F_fIs at a vertical spacing z from the ground₀(ii) a Center of mass of cargo and F_fIs at a vertical spacing z₁；

And the number of the first and second electrodes,

x_c＝-(l₀+l₁)，y_c＝b/2-b₁；z_c＝z₀+z₁。

preferably, the pressure F is obtained from the front left end corner of the goods₁Taking the pressure F from the front right corner of the cargo₂Taking the pressure F from the rear left end corner of the cargo₃Obtaining pressure F from the rear right end corner of the goods₄Wherein F is₁+F₂＝F_f，F₃+F₄＝F_b，F₁+F₃＝F_l，F₂+F₄＝F_r。

The system for acquiring the center of mass position of the towed trailer disclosed by the invention is applied by combining a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system takes the projection of a hanging point of the trailer and a head of the trailer on the ground as an origin, the advancing direction of the head of the trailer is the X-axis forward direction, the left side of the head of the trailer is the Y-axis forward direction, and the vertically upward direction is the Z-axis forward direction, and the system for acquiring the center of mass position of the towed trailer comprises:

the angle sensor is used for detecting an included angle between the vehicle head and the trailer;

a cargo mass center obtaining subsystem for obtaining the coordinates (x) of the cargo mass center when the included angle between the trailer and the trailer is 0 degree_c，y_c，z_c)；

The vehicle head mass center acquisition module is used for acquiring a vehicle head mass center coordinate (x) when the included angle between the vehicle head and the trailer is 0 degree according to vehicle design parameters_a，y_a，z_a)；

The trailer mass center acquisition module is used for acquiring trailer mass center coordinates (x) when the included angle between the trailer head and the trailer is 0 degree according to vehicle design parameters_b，y_b，z_b)；

The whole vehicle mass center obtaining module is used for obtaining the included angle between the vehicle head and the trailer according to the formula when the included angle is theta:

and

the real-time coordinate of the center of mass of the whole vehicle is obtained by calculation as (x)_m，y_m，z_m) Wherein m is_aM is the weight of the vehicle head_bFor trailer mass, m_cIs the cargo quality.

Preferably, in the acquisition system, the cargo centroid acquisition subsystem includes:

an acceleration sensor for measuring acceleration of the tractor trailer;

a front end pressure sensor for acquiring the pressure F applied to the trailer by the front end of the cargo in the static state of the trailer_fWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the front end of the cargo is obtained_f’；

A rear end pressure sensor for acquiring the pressure F applied to the trailer by the rear end of the goods in the static state of the trailer_bWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the rear end of the cargo is obtained_b’；

A left side pressure sensor for acquiring the pressure F applied to the trailer by the left side of the goods in the static state of the trailer_l；

A right side pressure sensor for acquiring the pressure F applied to the trailer by the right side of the cargo in the static state of the trailer_r；

A cargo centroid acquisition module for: ,

x_c＝-(l₀+l₁)，y_c＝b/2-b₁；z_c＝z₀+z₁calculating to obtain coordinates (x) of the center of mass of the goods_c，y_c，z_c)；

Wherein the longitudinal distance between the front end pressure sensor and the rear end pressure sensor is l; the longitudinal distance between the origin and the left pressure sensor is l₀(ii) a The longitudinal distance between the center of mass of the cargo and the left pressure sensor is l₁(ii) a The transverse distance between the left side pressure sensor and the right side pressure sensor is b; the transverse distance between the center of mass of the cargo and the left pressure sensor is b₁(ii) a The vertical distance between the left pressure sensor and the ground is z₀(ii) a Center of mass of cargoThe vertical distance from the left pressure sensor is z₁。

Preferably, in the acquisition system, a first pressure sensor is arranged between the left front end corner of the cargo and the trailer, a second pressure sensor is arranged between the right front end corner of the cargo and the trailer, a third pressure sensor is arranged between the left rear end corner of the cargo and the trailer, and a fourth pressure sensor is arranged between the right rear end corner of the cargo and the trailer;

wherein the first pressure sensor and the second pressure sensor constitute the front end pressure sensor; the third pressure sensor and the fourth pressure sensor constitute the rear end pressure sensor; the first pressure sensor and the third pressure sensor constitute the left side pressure sensor; the second pressure sensor and the fourth pressure sensor constitute the right side pressure sensor.

Preferably, the vehicle head mass center acquisition module, the trailer mass center acquisition module, the whole vehicle mass center acquisition module and the cargo mass center acquisition module are integrated into a control unit.

According to the technical scheme, the method for acquiring the mass center position of the towing trailer disclosed by the invention can acquire the real-time coordinate of the mass center of the whole trailer when the included angle between the trailer and the trailer is theta in a three-dimensional rectangular coordinate system according to the coordinate of the mass center of the goods, the coordinate of the mass center of the trailer and the coordinate of the mass center of the trailer when the included angle between the trailer and the trailer is 0 DEG, and the position of the mass center of the whole trailer can be acquired in real time no matter the towing trailer is in a straight running state or a turning state, so that accurate parameters are provided for vehicle operation and control, and the running stability and safety of the vehicle are enhanced.

The system for acquiring the center of mass position of the towing trailer disclosed by the invention can realize the method for acquiring the center of mass position of the towing trailer, so that the system also has the corresponding technical advantages of the acquisition method, and the method is not repeated herein.

Drawings

FIG. 1 is a schematic diagram of a sensor and control unit layout on a trailer as disclosed in an embodiment of the present invention;

FIG. 2 is a side schematic view of a tractor trailer;

fig. 3 is a schematic top view of the tractor trailer turning.

Wherein, 1 is first pressure sensor, 2 is second pressure sensor, 3 is third pressure sensor, 4 is fourth pressure sensor, 5 is angle sensor, 6 is acceleration sensor, 7 is the control unit, and A is the locomotive barycenter, and B is the trailer barycenter, and C is the goods barycenter, and O is the original point.

Detailed Description

One of the cores of the invention is to provide a method for acquiring the position of the center of mass of the trailer so as to ensure the operation stability and the safety of the trailer.

Another core of the present invention is to provide a system for acquiring the position of the center of mass of a towed trailer.

The method for acquiring the center of mass position of the towing trailer disclosed by the invention is applied by combining a three-dimensional rectangular coordinate system, the three-dimensional rectangular coordinate system takes the projection of the hitching point of the trailer and the head on the ground as an origin, as shown in fig. 3, the advancing direction of the head is the X-axis forward direction, the left side of the head is the Y-axis forward direction, and the vertically upward direction is the Z-axis forward direction, and the method for acquiring the center of mass position of the towing trailer specifically comprises the following steps:

1): obtaining the barycenter coordinate (x) of the goods when the included angle between the vehicle head and the trailer is 0 degree_c，y_c，z_c)；

2) According to vehicle design parameters, a vehicle head mass center coordinate (x) is obtained when the included angle between the vehicle head and the trailer is 0 degree_a，y_a，z_a) And trailer centroid coordinates (x)_b，y_b，z_b) When the included angle between the head of the vehicle and the trailer is theta (the range is-15 degrees to 15 degrees including end point values), the real-time coordinate of the center of mass of the whole vehicle is (x)_m，y_m，z_m) According to the formula:

obtaining the real-time coordinate (x) of the mass center of the whole vehicle (the whole body formed by the vehicle head, the trailer and the goods on the vehicle)_m，y_m，z_m) M in the formula_aM is the weight of the vehicle head_bFor trailer mass, m_cIn the above embodiment, the coordinate values are unified in units of meters and the mass is unified in units of Kg for the cargo mass.

According to the technical scheme disclosed in the embodiment, the method for acquiring the mass center position of the towing trailer disclosed by the invention can acquire the real-time coordinate of the mass center of the whole trailer when the included angle between the trailer and the trailer is theta (change in the value range) in real time in the three-dimensional rectangular coordinate system according to the coordinate of the mass center of the goods, the coordinate of the mass center of the trailer and the coordinate of the mass center of the trailer when the included angle between the trailer and the trailer is 0 DEG, and the position of the mass center of the whole trailer can be acquired in real time no matter the towing trailer is in a straight-going state or a turning state, so that accurate parameters are provided for vehicle operation and control, and the driving stability and safety of the vehicle are enhanced.

It can be understood by those skilled in the art that the platform support reaction method, the mass reaction method, the suspension method, the swing method, the zero position method and the like can be used for determining the centroid of the static object, which are well known to those skilled in the art, so that in the above embodiment, the centroid of the cargo can be obtained by the method when the included angle between the trailer and the trailer is 0 °, and then the coordinates (x) of the centroid of the cargo in the three-dimensional rectangular coordinate system can be determined according to the size and the position of the cargo_c，y_c，z_c) And (4) finishing.

In one embodiment, the method for obtaining the center of mass of the goods when the included angle between the vehicle head and the trailer is 0 ° is as follows:

obtaining the pressure F applied to the trailer by the front end of the goods in a static state_fPressure F applied to the trailer by the rear end of the cargo_bPressure F applied to the trailer on the left side of the cargo_lAnd the pressure F applied to the trailer by the right side of the cargo_r(ii) a Acquiring the pressure F applied to the trailer by the front end of the cargo when the acceleration is a_f', pressure F applied to the trailer at the rear end of the cargo_b’；

Wherein, F_fAnd F_bThe longitudinal distance between the acquisition positions is l; origin and F_fIs longitudinally spaced by a distance l₀(ii) a Center of mass of cargo and F_fHas a longitudinal spacing of l₁；F_lAnd F_rThe lateral spacing between the acquisition positions of (a) is b; center of mass of cargo and F_lHas a lateral spacing of b₁；F_fIs at a vertical spacing z from the ground₀(ii) a Center of mass of cargo and F_fIs at a vertical spacing z₁；

In the present invention, it is to be noted that: the "longitudinal distance" specifically means a distance in the X-axis direction, the "lateral distance" specifically means a distance in the Y-axis direction, and the "vertical distance" specifically means a distance in the Z-axis direction, and in the present invention, F is_fThe acquisition position of (F)_bThe acquisition position of (F)_lAnd F_rThe coordinates of the acquisition positions on the Z axis are equal, F_lAnd F_rIs symmetric about the X-axis.

From the moment balance equation, one can obtain:

F_f l₁＝F_b(l-l₁) (1)

F_l b₁＝F_r(b-b₁) (2)

from the moment equation, one can obtain:

-m_caz₁＝F_f’l₁-F_b’(l-l₁) (3)

from equations (1) and (2) yieldsAnd

from equation (3) to

And according to the formula: x is the number of_c＝-(l₀+l₁) (4)

y_c＝b/2-b₁ (5)

z_c＝z₀+z₁ (6)

Obtaining coordinates (x) of center of mass of goods_c，y_c，z_c)。

Pressure F applied by the front end of the load to the trailer_fAnd the pressure F applied by the rear end of the cargo to the trailer_bThe front end measuring point and the rear end measuring point can be obtained respectively, and are positioned on the X axis; pressure F applied to the trailer on the left side of the cargo_lAnd the pressure F applied to the trailer by the right side of the cargo_rThe measurement points can be obtained through a left side measurement point and a right side measurement point respectively, and the left side measurement point and the right side measurement point are arranged along the Y-axis direction and are symmetrically distributed about the X-axis.

As shown in fig. 1, in the present embodiment, a pressure measurement point is respectively disposed at the front left end corner, the front right end corner, the rear left end corner and the rear right end corner of the cargo, and the pressure obtained from the front left end corner of the cargo is F₁The pressure taken from the front right end corner of the cargo is F₂The pressure taken from the rear left end corner of the cargo is F₃The pressure obtained from the rear right end corner of the cargo is F₄Wherein F is₁+F₂＝F_f，F₃+F₄＝F_b，F₁+F₃＝F_l，F₂+F₄＝F_rThat is, the front left end of the cargoPressure F of corner acquisition pressure₁Pressure F taken from the front right end corner of the cargo₂The resultant force of (a) is the pressure F applied by the front end of the cargo to the trailer_f(ii) a Pressure F for taking pressure from rear left end corner of cargo₃And the pressure F obtained from the corner of the rear right end of the goods₄The resultant force of (a) is the pressure F applied by the front end of the cargo to the trailer_b(ii) a Pressure F for acquiring pressure from front left end corner of cargo₁Pressure F taken from the rear left end corner of the load₃Resulting force of pressure F applied to the trailer by the left side of the cargo_l(ii) a Pressure F for acquiring pressure from front right end corner of cargo₂And the pressure F obtained from the corner of the rear right end of the goods₄The resultant force of (a) is the pressure F applied by the front end of the cargo to the trailer_r(ii) a Of course, in the case of acceleration a, the pressure F exerted by the front end of the load on the trailer_f'should be F'₁+F’₂Pressure F applied to the trailer by the rear end of the cargo_b'should be F'₃+F’₄。

From the moment balance equation, one can obtain:

(F₁+F₂)l₁＝(F₃+F₄)(l-l₁) (101)

(F₁+F₃)b₁＝(F₂+F₄)(b-b₁) (201)

from the moment equation, one can obtain:

-m_caz₁＝(F’₁+F’₂)l₁-(F’₃+F’₄)(l-l₁) (301)

from equations (101) and (201) yieldsAnd

from equation (301) to

And according to the formula: (4) obtaining coordinates (x) of the center of mass of the goods by the steps (5) and (6)_c，y_c，z_c)。

When the included angle between the vehicle head and the trailer is 0 degrees, the coordinate of the mass center of the vehicle head is recorded as (x)_a，y_a，z_a) The coordinate of the center of mass of the trailer is (x)_b，y_b，z_b) The coordinates of the center of mass of the cargo are (x)_c，y_c，z_c) When the included angle between the trailer and the locomotive is theta, the position of the mass center of the locomotive is unchanged, and the coordinate of the mass center of the trailer is (x'_b，y’_b，z’_b) Coordinates of center of mass of cargo is (x'_c，y’_c，z’_c) And obtaining the following data in a three-dimensional rectangular coordinate system according to the geometrical relationship:

z'_b＝z_b (9)

z'_c＝z_c (12)

and (7), (8), (9), (10), (11) and (12) are combined to obtain the mass center of the whole vehicle as follows:

x'_b、y’_b、x’_c、y’_cAnd z'_cSubstituting the formula to obtain:

in addition, the invention also discloses a system for acquiring the mass center position of the trailer, which is applied by combining a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system takes the projection of a hanging point of the trailer and a head of the trailer on the ground as an origin, the advancing direction of the head of the trailer is the X-axis forward direction, the left side of the head of the trailer is the Y-axis forward direction, and the vertically upward direction is the Z-axis forward direction, the system comprises an angle sensor 5, a cargo mass center acquisition subsystem, a head mass center acquisition module, a trailer mass center acquisition module and a whole vehicle mass center acquisition module, wherein the angle sensor 5 is used for detecting the included angle between the head of the trailer, and the cargo mass center acquisition subsystem is used for acquiring the coordinates (X) of the cargo when the included angle_c，y_c，z_c) The vehicle head mass center acquisition module is used for acquiring a vehicle head mass center coordinate (x) when the included angle between the vehicle head and the trailer is 0 degree according to vehicle design parameters_a，y_a，z_a) The trailer mass center acquisition module is used for acquiring a trailer hitch when the included angle between the trailer head and the trailer is 0 degree according to vehicle design parametersVehicle centroid coordinate (x)_b，y_b，z_b) When the included angle that the module is used for between locomotive and the trailer is theta in whole car barycenter, according to the formula:

and

the real-time coordinate of the center of mass of the whole vehicle is obtained by calculation as (x)_m，y_m，z_m) Wherein m is_aM is the weight of the vehicle head_bFor trailer mass, m_cIs the cargo quality.

Further, the cargo centroid obtaining subsystem specifically comprises an acceleration sensor 6, a front end pressure sensor, a rear end pressure sensor, a left end pressure sensor, a right end pressure sensor and a centroid obtaining module, wherein the acceleration sensor 6 is used for measuring the acceleration of the trailer, and the front end pressure sensor is used for obtaining the pressure F applied to the trailer by the front end of the cargo in the static state of the trailer_fWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the front end of the cargo is obtained_f', the rear end pressure sensor is used for acquiring the pressure F applied to the trailer by the rear end of the goods in the static state of the trailer_bWhen the acceleration of the trailer is a, the pressure F applied to the trailer by the rear end of the cargo is obtained_b' left side pressure sensor is used for obtaining the pressure F applied to the trailer by the left side of goods in the static state of the towing trailer_lThe right side pressure sensor is used for acquiring the pressure F applied to the trailer by the right side of the cargo in the static state of the towing trailer_rThe cargo centroid acquisition module is used for acquiring a cargo centroid according to a formula: ,

x_c＝-(l₀+l₁)，y_c＝b/2-b₁；z_c＝z₀+z₁calculating to obtain coordinates (x) of the center of mass of the goods_c，y_c，z_c)；

The longitudinal distance between the front end pressure sensor and the rear end pressure sensor is l; the longitudinal distance between the origin and the left pressure sensor is l₀(ii) a The longitudinal distance between the center of mass of the cargo and the left pressure sensor is l₁(ii) a The transverse distance between the left side pressure sensor and the right side pressure sensor is b; the transverse distance between the center of mass of the cargo and the left pressure sensor is b₁(ii) a The vertical distance between the left pressure sensor and the ground is z₀(ii) a The vertical distance between the center of mass of the cargo and the left pressure sensor is z₁。

Referring to fig. 1 to 3, a first pressure sensor 1 is arranged between a left front end corner of the cargo and the trailer, a second pressure sensor 2 is arranged between a right front end corner of the cargo and the trailer, a third pressure sensor 3 is arranged between a left rear end corner of the cargo and the trailer, and a fourth pressure sensor 4 is arranged between a right rear end corner of the cargo and the trailer;

the first pressure sensor 1 and the second pressure sensor 2 form a front end pressure sensor; the third pressure sensor 3 and the fourth pressure sensor 4 constitute a rear end pressure sensor; the first pressure sensor 1 and the third pressure sensor 3 constitute a left side pressure sensor; the second pressure sensor 2 and the fourth pressure sensor 4 constitute a right-side pressure sensor.

Further, a vehicle head mass center acquisition module, a trailer mass center acquisition module, a whole vehicle mass center acquisition module and a cargo mass center acquisition module are integrated into the control unit 7, as shown in fig. 1.

The method and the system for acquiring the center of mass of the towed trailer provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.