CN114355952B - Unmanned vehicle trafficability assessment method and system - Google Patents

Abstract

The present invention relates to a method and system for assessing the accessibility of an unmanned vehicle. The method includes determining the adhesion of the tire in the current working condition, and then determining the maximum pitch angle and the maximum inclination angle allowed by the vehicle; The coordinates of the landing point, the current pitch angle and the current tilt angle of each tire; the first judgment is made according to the basic information and the coordinates of the landing point; and when the first judgment result is passable, the coordinates of the landing point of the four tires of the unmanned vehicle and The current position and heading angle of the unmanned vehicle determine the vehicle support surface, and determine the vehicle support surface map according to all the elevation information in the vehicle support surface; make a second judgment according to the elevation information in the vehicle support surface map, and when the second judgment result When it is passable, control the unmanned vehicle to drive from the current position. The invention can ensure the safety of the unmanned vehicle running on the unstructured road.

Description

A method and system for assessing the accessibility of unmanned vehicles

technical field

The invention relates to the field of path planning, in particular to a method and system for assessing the passability of an unmanned vehicle.

Background technique

Unmanned vehicles (referred to as unmanned vehicles) have become a research hotspot in recent years. Local path planning of unmanned vehicles is one of its key technologies, and its performance directly determines the success of unmanned vehicles. The main feature of the unstructured road environment is the diversity of terrain features. In addition to some terrains that are easier to distinguish whether they are passable, such as embankments and vertical slopes, there are also some terrains that are not easy to distinguish whether they are passable, such as craters and ravines. , mounds, etc. Therefore, compared with the local path planning technology for unmanned vehicles in the structured road environment, the local path planning technology for the unstructured road environment is less studied, and there is no mature solution so far.

The existing local planning methods in the unstructured road environment are mostly inherited from the path planning on the two-dimensional plane in the structured road environment. Make safe and smooth path planning. The above-mentioned "it is not easy to distinguish whether the terrain is passable" is placed in the perception layer, or it is simply judged by using the elevation information. These schemes make the planner have defects such as incomplete solution space or failure to solve on some special terrains, and further, cannot guarantee the traversability of unmanned vehicles on some unstructured terrains.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method and system for assessing the accessibility of unmanned vehicles, which can ensure the safety of unmanned vehicles driving on unstructured roads.

For achieving the above object, the present invention provides the following scheme:

A method for assessing the accessibility of unmanned vehicles, including:

Obtain the basic information of the unmanned vehicle and the current position and heading angle in the 2.5D terrain attribute map; the coordinate information of the data points in the 2.5D terrain attribute map includes: elevation information; the basic information includes: vehicle length and vehicle width ;

According to the vertical reaction force of the tire of the unmanned vehicle at the current position and the adhesion coefficient of the current road surface, the adhesion force of the tire under the current working condition is determined, and then the maximum pitch angle and maximum inclination angle allowed by the vehicle are determined;

According to the basic information of the unmanned vehicle, the current position and heading angle in the 2.5D terrain attribute map, and the maximum pitch angle and maximum tilt angle allowed by the vehicle, determine the coordinates of the landing point, the current pitch angle and the current tilt of the four tires of the unmanned vehicle horn;

The first judgment is made according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle; and when the first judgment result is passable, according to the coordinates of the landing point of the four tires of the unmanned vehicle and the location The current position and heading angle determine the vehicle support surface, and determine the vehicle support surface map according to all the elevation information in the vehicle support surface;

The second judgment is made according to the elevation information in the map of the vehicle support surface, and when the second judgment result is passable, the unmanned vehicle is controlled to travel from the current position.

Optionally, according to the basic information of the unmanned vehicle, the current position and heading angle in the 2.5D terrain attribute map, and the maximum pitch angle and maximum inclination angle allowed by the vehicle, determine the coordinates and coordinates of the landing point of the four tires of the unmanned vehicle. Current pitch angle and current tilt angle, including:

Determine the projected length range of the vehicle length on the horizontal plane and the projected length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and maximum tilt angle allowed by the vehicle;

The goal is to minimize the projected length of the length and width of the unmanned vehicle on the horizontal plane, and the projected length range of the length of the unmanned vehicle on the horizontal plane and the projected length of the vehicle width on the horizontal plane are the constraints to construct the target. function;

Determine the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the objective function;

According to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane, the coordinates of the landing point, the current pitch angle and the current tilt angle of the four tires of the unmanned vehicle are determined.

Optionally, the first judgment is performed according to the basic information of the unmanned vehicle and the coordinates of the landing points of the four tires of the unmanned vehicle, which specifically includes:

According to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle, the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, and the difference between the distance between the right front wheel and the right rear wheel and the vehicle length are respectively determined. value, the difference between the distance between the left front wheel and the right front wheel and the vehicle width, and the difference between the distance between the left rear wheel and the right rear wheel and the vehicle width;

Determine the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference between the distance between the right front wheel and the right rear wheel and the vehicle length, the difference between the distance between the left front wheel and the right front wheel and the vehicle width and the left Whether the difference between the distance between the rear wheel and the right rear wheel and the vehicle width is smaller than the first set threshold;

If both are smaller than the first set threshold, the first judgment result is passable; otherwise, the first judgment result is impassable.

Optionally, the second judgment is performed according to the elevation information in the vehicle support surface map, and when the second judgment result is passable, the unmanned vehicle is controlled to drive from the current position, which specifically includes:

Convert each coordinate in the vehicle support surface map to the vehicle projection coordinate system;

The converted vehicle support surface map is divided into three areas; the three areas are a first area, a second area and a third area; the second area is located in the middle of the converted vehicle support surface map;

Convert the coordinates of the second area to coordinates, and determine the position of the highest point according to the converted elevation information;

Determine whether the position of the highest point is greater than or equal to the vehicle chassis height; if so, it is passable; otherwise, it is impassable;

Determine the lateral gradient according to the elevation information in the first area and the third area; determine whether the lateral gradient is greater than or equal to the lateral gradient threshold; if yes, it is passable; otherwise, it is impassable.

An unmanned vehicle passability assessment system, comprising:

The data acquisition module is used to acquire the basic information of the unmanned vehicle and the current position and heading angle in the 2.5D terrain attribute map; the coordinate information of the data points in the 2.5D terrain attribute map includes: elevation information; the basic information includes : vehicle length and vehicle width;

The module for determining the maximum pitch angle and the maximum tilt angle is used to determine the adhesion force of the tire in the current working condition according to the vertical reaction force of the tire of the unmanned vehicle at the current position and the adhesion coefficient of the current road surface, and then determine the maximum allowable pitch angle and maximum Tilt angle;

The module for determining the coordinates of the landing point and the current pitch angle and current tilt angle of the four tires of the unmanned vehicle is used to determine the module based on the basic information of the unmanned vehicle, the current position and heading angle in the 2.5D terrain attribute map, and the maximum allowable pitch of the vehicle The angle and the maximum inclination angle determine the coordinates of the landing point, the current pitch angle and the current inclination angle of the four tires of the unmanned vehicle;

The first judgment module is used to make a first judgment according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle; and when the first judgment result is passable, according to the position of the four tires of the unmanned vehicle. The location coordinates and the current position and heading angle of the unmanned vehicle determine the vehicle support surface, and determine the vehicle support surface map according to all the elevation information in the vehicle support surface;

The second judgment module is configured to perform a second judgment according to the elevation information in the vehicle support surface map, and when the second judgment result is passable, control the unmanned vehicle to travel from the current position.

Optionally, the location coordinates of the four tires of the unmanned vehicle, the current pitch angle and the current tilt angle determination module specifically include:

The projection length range determination unit is used to determine the projection length range of the vehicle length on the horizontal plane and the projection length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and the maximum tilt angle allowed by the vehicle. ;

The objective function construction unit is used to take the minimum projection length of the length and width of the unmanned vehicle on the horizontal plane as the goal, and take the projection length range of the length of the unmanned vehicle on the horizontal plane and the projected length of the vehicle width on the horizontal plane. The scope is the constraint condition, and the objective function is constructed;

The optimal projection length determining unit is used to determine the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the objective function;

The unit for determining the location coordinates of the four tires of the unmanned vehicle and the current pitch angle and current inclination angle is used to determine the four tires of the unmanned vehicle according to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane. The coordinates of the landing point and the current pitch angle and current tilt angle.

Optionally, the first judgment module specifically includes:

The difference determination unit is used to determine the difference between the distance between the left front wheel and the left rear wheel and the length of the vehicle, the right front wheel and the right rear wheel according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle. The difference between the distance and the vehicle length, the difference between the distance between the left front wheel and the right front wheel and the width of the vehicle, and the difference between the distance between the left rear wheel and the right rear wheel and the width of the vehicle;

The first judgment unit is used to judge the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference between the distance between the right front wheel and the right rear wheel and the vehicle length, and the distance between the left front wheel and the right front wheel. Whether the difference between the vehicle width and the distance between the left rear wheel and the right rear wheel and the vehicle width is less than the first set threshold; if both are less than the first set threshold, the first judgment result is passable; otherwise, Then the first judgment result is that it is impassable.

Optionally, the second judgment module specifically includes:

The coordinate conversion unit is used to convert each coordinate in the vehicle support surface map to the vehicle projection coordinate system;

The map dividing unit is used to divide the converted vehicle support surface map into three areas; the three areas are a first area, a second area and a third area; the second area is located in the converted vehicle support surface map in the middle;

The position determination unit of the highest point, which is used for coordinate transformation of the coordinates of the second area, and determines the position of the highest point according to the converted elevation information;

The second judgment unit is used to judge whether the position of the highest point is greater than or equal to the height of the vehicle chassis; if so, it is passable; otherwise, it is impassable;

The third judging unit is used for determining the lateral gradient according to the elevation information in the first area and the third area; judging whether the lateral gradient is greater than or equal to the lateral gradient threshold; if yes, it is passable; otherwise, it is impassable.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The method and system for assessing the accessibility of an unmanned vehicle provided by the present invention are based on the basic information of the unmanned vehicle, the current position and heading angle in the 2.5D terrain attribute map, and the maximum pitch angle and maximum inclination allowed by the vehicle. The location coordinates of the four tires of the unmanned vehicle determined by the angle and the current pitch angle and current inclination angle are determined to be passable, that is, the attitude angle of the vehicle is considered, and it is not simply based on whether the highest point of the obstacle is higher than the vehicle chassis. judge. First, calculate the supporting surface of the vehicle according to the landing point of the vehicle tires to obtain the angle of the supporting surface, and then perform coordinate transformation of the elevation information inside the supporting surface to obtain the converted elevation information, and obtain the highest point to determine whether it will be rubbed or not. chassis. It can not only ensure the driving stability of the unmanned vehicle in a relatively wide passable area, but also ensure the passability of the unmanned vehicle in a narrow passable area.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

1 is a schematic flowchart of a method for assessing the accessibility of an unmanned vehicle provided by the present invention;

2 is a schematic diagram of a specific embodiment of performing a first judgment according to the basic information of the unmanned vehicle and the coordinates of the landing points of the four tires of the unmanned vehicle;

3 is a schematic diagram of a specific embodiment of judging whether the position of the highest point is greater than or equal to the height of the vehicle chassis;

4 is a schematic diagram of a specific embodiment of judging whether the lateral gradient is greater than or equal to the lateral gradient threshold;

Fig. 5 is a schematic diagram of crossing obstacles in a narrow passable area;

FIG. 6 is a schematic structural diagram of an unmanned vehicle passability assessment system provided by the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a method and system for assessing the accessibility of unmanned vehicles, which can ensure the safety of unmanned vehicles driving on unstructured roads.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic flowchart of a method for assessing the accessibility of an unmanned vehicle provided by the present invention. As shown in FIG. 1 , the method for assessing the accessibility of an unmanned vehicle provided by the present invention includes:

S101, obtain basic information of the unmanned vehicle and the current position and heading angle in the 2.5D terrain attribute map; the coordinate information of the data points in the 2.5D terrain attribute map includes: elevation information; the basic information includes: vehicle length and vehicle width;

可通行区域地图

长为

，宽为

，地图

在坐标系

下由

个数据点表示，每个数据点仅包含了高程信息，即

，

。通过坐标值

索引地图中对应的数据点，获得高程信息，可以通过公式：In S101, a passable 2.5D terrain attribute map is drawn to describe the passable area around the vehicle by collecting multi-sensor data including at least a laser point cloud. The more obvious impassable areas, such as higher embankments, larger deep pits, have been deleted. Retain some terrain that cannot be clearly judged whether it is passable, and retain the original information, waiting for path planning to be screened. Choose a more convenient fixed point to establish a fixed Cartesian coordinate system

Passable area map

long for

, the width is

,map

in the coordinate system

down by

data points, each data point only contains elevation information, that is

,

. by coordinate value

To index the corresponding data points in the map to obtain the elevation information, you can use the formula:

；

;

Also give the map resolution:

；

;

和最大倾斜角

作为俯仰角与侧倾角约束，使车辆能够稳定行驶，避免滑移的风险。保证车辆不会发生滑移或者翻转即：S102: Determine the adhesion force of the tire under the current working condition according to the vertical reaction force on the tire of the unmanned vehicle at the current position and the adhesion coefficient of the current road surface, and then determine the maximum allowable pitch angle and maximum tilt angle of the vehicle; the maximum allowable pitch angle of the vehicle is to be determined.

and the maximum tilt angle

As pitch and roll angle constraints, it enables the vehicle to drive stably and avoid the risk of slippage. To ensure that the vehicle does not slip or roll over i.e.:

；

;

；

;

和航向角

以及车辆允许的最大俯仰角和最大倾斜角确定无人车四个轮胎的着地点坐标和当前俯仰角及当前倾斜角；S103, according to the basic information of the unmanned vehicle and the current position in the 2.5D terrain attribute map

and heading angle

And the maximum pitch angle and maximum tilt angle allowed by the vehicle to determine the coordinates of the landing point and the current pitch angle and current tilt angle of the four tires of the unmanned vehicle;

S103 specifically includes:

Determine the projected length range of the vehicle length on the horizontal plane and the projected length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and maximum tilt angle allowed by the vehicle;

，则当车辆俯仰角

时，车长在水平面上投影长度

；当车辆俯仰角

时，车长在水平面上投影长度

。因此可以得到车长在水平面上的投影长度范围：The projected length of the vehicle length on the horizontal plane

, then when the vehicle pitch angle

, the projected length of the vehicle length on the horizontal plane

;When the vehicle pitch angle

, the projected length of the vehicle length on the horizontal plane

. Therefore, the projected length range of the vehicle length on the horizontal plane can be obtained:

；

;

In the same way, the projected length range of the vehicle width on the horizontal plane can be obtained:

；

;

The goal is to minimize the projected length of the length and width of the unmanned vehicle on the horizontal plane, and the projected length range of the length of the unmanned vehicle on the horizontal plane and the projected length of the vehicle width on the horizontal plane are the constraints to construct the target. function;

The objective function is:

；

;

；

;

；

;

；

;

；in,

;

；

;

；

;

；

;

，

，

分别对应四轮车右后轮，右前轮，左前轮，左后轮的坐标。

,

,

Corresponding to the coordinates of the right rear wheel, right front wheel, left front wheel and left rear wheel of the four-wheeled vehicle respectively.

Determine the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the objective function;

的采样间隔不小于地图的分辨率

。最终得到最优解

。Because the optimization problem contains discrete variables, the most direct traversal search method is used to find the optimal solution, that is, two for loops are nested to optimize variables.

The sampling interval is not less than the resolution of the map

. finally get the optimal solution

.

、以及俯仰角

和倾斜角

。Substituting the optimal solution into the above formula, we can get

, and the pitch angle

and tilt angle

.

According to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane, the coordinates of the landing point, the current pitch angle and the current tilt angle of the four tires of the unmanned vehicle are determined.

；

；S104, make a first judgment according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle; and when the first judgment result is passable, according to the coordinates of the landing point of the four tires of the unmanned vehicle and the coordinates of the unmanned vehicle The current position and heading angle of the vehicle determine the vehicle support surface, and determine the vehicle support surface map according to all the elevation information in the vehicle support surface

;

;

S104 specifically includes:

According to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle, the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, and the difference between the distance between the right front wheel and the right rear wheel and the vehicle length are respectively determined. value, the difference between the distance between the left front wheel and the right front wheel and the vehicle width, and the difference between the distance between the left rear wheel and the right rear wheel and the vehicle width;

；

为一个较小的非负阈值。As shown in Figure 2, determine the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference between the distance between the right front wheel and the right rear wheel and the vehicle length, and the distance between the left front wheel and the right front wheel and the vehicle length. Whether the difference in width and the difference between the distance between the left rear wheel and the right rear wheel and the vehicle width are all smaller than the first set threshold

;

is a small non-negative threshold.

If both are smaller than the first set threshold, the first judgment result is passable; otherwise, the first judgment result is impassable.

时可通行；否则，不可通行；that is satisfied

passable; otherwise, impassable;

S105, a second judgment is performed according to the elevation information in the vehicle support surface map, and when the second judgment result is that the vehicle is passable, the unmanned vehicle is controlled to travel from the current position.

S105 specifically includes:

Convert each coordinate in the vehicle support surface map to the vehicle projection coordinate system; that is, only consider the rotation around the h-axis, the formula is as follows:

；

;

将转换后的车辆支撑面地图划分为三个区域；三个区域为第一区域

、第二区域

和第三区域

；所述第二区域位于转换后的车辆支撑面地图的中间位置；Use the formula

Divide the converted vehicle support surface map into three areas; the three areas are the first area

, the second area

and the third area

; the second area is located in the middle of the converted vehicle support surface map;

是轮胎直径，

是前轮转角，当待测参考路径给出后，很容易得到车辆到达某个点的前轮转角，如果无法得到前轮转角，可以令

，

为最大前轮转角；

是地图

宽。in,

is the tire diameter,

is the front wheel turning angle. When the reference path to be tested is given, it is easy to get the front wheel turning angle at which the vehicle reaches a certain point. If the front wheel turning angle cannot be obtained, you can make

,

is the maximum front wheel turning angle;

is a map

width.

Convert the coordinates of the second area to coordinates, and determine the position of the highest point according to the converted elevation information;

为基础建立坐标系

，坐标原点为

，轴X平行且同向于向量

，轴Y平行且同向于

，轴H垂直于

与

组成的平面，方向向上。对

再进行两次旋转操作，既可以将原始高程信息映射到坐标系

上，公式如下：by

Create a coordinate system for the base

, the coordinate origin is

, the axis X is parallel and in the same direction as the vector

, the axis Y is parallel and in the same direction as

, the axis H is perpendicular to

and

Consists of a plane, oriented upwards. right

Perform two more rotation operations to map the original elevation information to the coordinate system

, the formula is as follows:

;

;

Determine whether the position of the highest point is greater than or equal to the vehicle chassis height; if so, it is passable; otherwise, it is impassable;

使得

，则可通行；反之，不可通行。if it exists

make

, it is passable; otherwise, it is impassable.

为车辆底盘高度。in,

is the vehicle chassis height.

Determine the lateral gradient according to the elevation information in the first area and the third area; determine whether the lateral gradient is greater than or equal to the lateral gradient threshold; if yes, it is passable; otherwise, it is impassable.

侧向梯度，公式如下Calculated using the multi-order difference formula

Lateral gradient, the formula is as follows

；

;

；

;

或者

，则不可通行；否则，可通行。if

or

, it is not passable; otherwise, it is passable.

，

为设定的侧向梯度阈值。in

,

is the set lateral gradient threshold.

The present invention can evaluate the traversability of paths on a relatively simple two-dimensional grid map. A simple two-dimensional raster map with elevation information is made by using relatively primitive point cloud information. Only the perception module is required to make very detailed feature distinctions. The method uses the landing of the unmanned vehicle wheel to complete the angle of the pitch angle and the inclination angle, which is more in line with the actual situation. The trafficability assessment can effectively distinguish the terrain where the wheel is suspended and the terrain of the embankment vertically downward. This method makes a reasonable judgment on whether the raised terrain scratches the chassis. Considering whether the raised terrain scratches the chassis, it is necessary to fully consider that the chassis will be raised when the vehicle is pitched and tilted, so mapping the elevation information to the wheel support surface, and then judging the accessibility is more in line with the actual situation. This method makes a reasonable judgment on whether the uneven terrain can support the running of the tire. This method is sufficient for the degree of inclination of one side of the tire on the ground. If the inclination exceeds the threshold, the road surface is likely to be crushed by the wheel, causing sideslip, or the wheel may be stuck. When facing a relatively narrow passable area in an unstructured environment, the method can also try to find a passable area as much as possible. The effect is shown in Figure 5.

FIG. 6 is a schematic structural diagram of an unmanned vehicle passability assessment system provided by the present invention. As shown in FIG. 6 , an unmanned vehicle passability assessment system provided by the present invention includes:

The data acquisition module 601 is used to acquire the basic information of the unmanned vehicle and the current position and heading angle in the 2.5D terrain attribute map; the coordinate information of the data points in the 2.5D terrain attribute map includes: elevation information; the basic information Including: vehicle length and vehicle width;

The maximum pitch angle and maximum inclination angle determination module 602 is used to determine the adhesion force of the tire in the current working condition according to the vertical reaction force that the tire of the unmanned vehicle is subjected to at the current position and the adhesion coefficient of the current road surface, and then determine the maximum allowable pitch angle and maximum inclination angle;

The coordinates of the landing point and the current pitch angle and current tilt angle of the four tires of the unmanned vehicle are determined by the module 603, which is used to determine the module 603 according to the basic information of the unmanned vehicle, the current position and heading angle in the 2.5D terrain attribute map, and the maximum allowable vehicle The pitch angle and the maximum tilt angle determine the coordinates of the landing point and the current pitch angle and current tilt angle of the four tires of the unmanned vehicle;

The first judgment module 604 is used to make a first judgment according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle; and when the first judgment result is passable, according to the four tires of the unmanned vehicle. The coordinates of the landing point and the current position and heading angle of the unmanned vehicle determine the vehicle support surface, and determine the vehicle support surface map according to all the elevation information in the vehicle support surface;

The second determination module 605 is configured to perform a second determination according to the elevation information in the vehicle support surface map, and when the second determination result is passable, control the unmanned vehicle to drive from the current position.

The location coordinates of the four tires of the unmanned vehicle, the current pitch angle and the current tilt angle determination module 603 specifically include:

The projection length range determination unit is used to determine the projection length range of the vehicle length on the horizontal plane and the projection length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and the maximum tilt angle allowed by the vehicle. ;

The objective function construction unit is used to take the minimum projection length of the length and width of the unmanned vehicle on the horizontal plane as the goal, and take the projection length range of the length of the unmanned vehicle on the horizontal plane and the projected length of the vehicle width on the horizontal plane. The scope is the constraint condition, and the objective function is constructed;

The optimal projection length determining unit is used to determine the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the objective function;

The unit for determining the location coordinates of the four tires of the unmanned vehicle and the current pitch angle and current inclination angle is used to determine the four tires of the unmanned vehicle according to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane. The coordinates of the landing point and the current pitch angle and current tilt angle.

The first judgment module 604 specifically includes:

The difference determination unit is used to determine the difference between the distance between the left front wheel and the left rear wheel and the length of the vehicle, the right front wheel and the right rear wheel according to the basic information of the unmanned vehicle and the coordinates of the landing point of the four tires of the unmanned vehicle. The difference between the distance and the vehicle length, the difference between the distance between the left front wheel and the right front wheel and the width of the vehicle, and the difference between the distance between the left rear wheel and the right rear wheel and the width of the vehicle;

The first judgment unit is used to judge the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference between the distance between the right front wheel and the right rear wheel and the vehicle length, and the distance between the left front wheel and the right front wheel. Whether the difference between the vehicle width and the distance between the left rear wheel and the right rear wheel and the vehicle width is less than the first set threshold; if both are less than the first set threshold, the first judgment result is passable; otherwise, Then the first judgment result is that it is impassable.

The second judgment module 605 specifically includes:

The coordinate conversion unit is used to convert each coordinate in the vehicle support surface map to the vehicle projection coordinate system;

The map dividing unit is used to divide the converted vehicle support surface map into three areas; the three areas are a first area, a second area and a third area; the second area is located in the converted vehicle support surface map in the middle;

The position determination unit of the highest point, which is used for coordinate transformation of the coordinates of the second area, and determines the position of the highest point according to the converted elevation information;

The second judgment unit is used to judge whether the position of the highest point is greater than or equal to the height of the vehicle chassis; if so, it is passable; otherwise, it is impassable;

The third judging unit is used for determining the lateral gradient according to the elevation information in the first area and the third area; judging whether the lateral gradient is greater than or equal to the lateral gradient threshold; if yes, it is passable; otherwise, it is impassable.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (4)

1. An unmanned vehicle trafficability assessment method is characterized by comprising the following steps:

acquiring basic information of the unmanned vehicle and a current position and a course angle in a 2.5D terrain attribute map; the coordinate information for data points in the 2.5D terrain attribute map includes: elevation information; the basic information includes: vehicle length and width;

determining the current working condition adhesive force of the tire according to the vertical reaction force of the tire of the unmanned vehicle on the current position and the current road adhesion coefficient, and further determining the maximum pitch angle and the maximum inclination angle allowed by the vehicle;

determining the landing coordinates, the current pitch angle and the current inclination angle of four tires of the unmanned vehicle according to the basic information of the unmanned vehicle, the current position and the course angle in the 2.5D terrain attribute map and the maximum pitch angle and the maximum inclination angle allowed by the vehicle;

performing first judgment according to the basic information of the unmanned vehicle and the landing coordinates of the four tires of the unmanned vehicle; when the first judgment result is that the unmanned vehicle can pass, determining a vehicle supporting surface according to the landing coordinates of the four tires of the unmanned vehicle, the current position and the course angle of the unmanned vehicle, and determining a vehicle supporting surface map according to all elevation information in the vehicle supporting surface;

performing second judgment according to the elevation information in the vehicle supporting surface map, and controlling the unmanned vehicle to run from the current position when the second judgment result is passable;

the first judgment is carried out according to the basic information of the unmanned vehicle and the coordinates of the four tires of the unmanned vehicle, and the first judgment specifically comprises the following steps:

respectively determining the difference value between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference value between the distance between the right front wheel and the right rear wheel and the vehicle length, the difference value between the distance between the left front wheel and the right front wheel and the vehicle width and the difference value between the distance between the left rear wheel and the right rear wheel and the vehicle width according to the basic information of the unmanned vehicle and the landing coordinates of the four tires of the unmanned vehicle;

judging whether the difference value between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference value between the distance between the right front wheel and the right rear wheel and the vehicle length, the difference value between the distance between the left front wheel and the right front wheel and the vehicle width and the difference value between the distance between the left rear wheel and the right rear wheel and the vehicle width are all smaller than a first set threshold value;

if the first judgment result is smaller than the first set threshold, the first judgment result is passable; otherwise, the first judgment result is that the vehicle cannot pass;

the second judgment is carried out according to the elevation information in the vehicle supporting surface map, and when the second judgment result is passable, the unmanned vehicle is controlled to run from the current position, and the method specifically comprises the following steps:

converting each coordinate in the vehicle supporting surface map into a vehicle projection coordinate system;

dividing the converted vehicle supporting surface map into three areas; the three regions are a first region, a second region and a third region; the second area is located in the middle position of the converted vehicle supporting surface map;

performing coordinate conversion on the coordinates of the second area, and determining the position of the highest point according to the converted elevation information;

judging whether the position of the highest point is greater than or equal to the height of the vehicle chassis; if yes, the user can pass through; otherwise, the user cannot pass;

determining a lateral gradient from elevation information in the first and third regions; judging whether the lateral gradient is greater than or equal to a lateral gradient threshold value; if yes, the user can pass through; otherwise, it is not accessible.

2. The method for assessing the trafficability of an unmanned vehicle according to claim 1, wherein the determining of the coordinates of the landed area, the current pitch angle and the current bank angle of the four tires of the unmanned vehicle according to the basic information of the unmanned vehicle, the current position and the heading angle in the 2.5D terrain attribute map, and the maximum pitch angle and the maximum bank angle allowed by the vehicle comprises:

determining the projection length range of the vehicle length of the unmanned vehicle on the horizontal plane and the projection length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and the maximum inclination angle allowed by the vehicle;

constructing an objective function by taking the minimum projection length of the unmanned vehicle and the projection length of the width of the vehicle on the horizontal plane as a target and taking the projection length range of the length of the unmanned vehicle on the horizontal plane and the projection length range of the width of the vehicle on the horizontal plane as constraint conditions;

determining the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the objective function;

and determining the landing coordinates, the current pitch angle and the current inclination angle of the four tires of the unmanned vehicle according to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane.

3. An unmanned vehicle trafficability evaluation system, comprising:

the data acquisition module is used for acquiring basic information of the unmanned vehicle and the current position and the current course angle in the 2.5D terrain attribute map; the coordinate information for data points in the 2.5D terrain attribute map includes: elevation information; the basic information includes: vehicle length and width;

the maximum pitch angle and maximum inclination angle determining module is used for determining the current working condition adhesive force of the tire according to the vertical reaction force of the tire of the unmanned vehicle in the current position and the current road adhesion coefficient, and further determining the maximum pitch angle and the maximum inclination angle allowed by the vehicle;

the system comprises a module for determining the landing coordinates, the current pitch angles and the current inclination angles of four tires of the unmanned vehicle, a module for determining the landing coordinates, the current pitch angles and the current inclination angles of the four tires of the unmanned vehicle according to the basic information of the unmanned vehicle, the current position and the course angle in a 2.5D terrain attribute map and the maximum pitch angles and the maximum inclination angles allowed by the vehicle;

the first judgment module is used for carrying out first judgment according to the basic information of the unmanned vehicle and the coordinates of the four tires of the unmanned vehicle; when the first judgment result is that the unmanned vehicle can pass, determining a vehicle supporting surface according to the landing coordinates of the four tires of the unmanned vehicle, the current position and the course angle of the unmanned vehicle, and determining a vehicle supporting surface map according to all elevation information in the vehicle supporting surface;

the second judgment module is used for carrying out second judgment according to the elevation information in the vehicle supporting surface map and controlling the unmanned vehicle to run from the current position when the second judgment result is passable;

the first judging module specifically comprises:

the difference determining unit is used for respectively determining the difference between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference between the distance between the right front wheel and the right rear wheel and the vehicle length, the difference between the distance between the left front wheel and the right front wheel and the vehicle width and the difference between the distance between the left rear wheel and the right rear wheel and the vehicle width according to the basic information of the unmanned vehicle and the landing coordinates of the four tires of the unmanned vehicle;

the first judgment unit is used for judging whether the difference value between the distance between the left front wheel and the left rear wheel and the vehicle length, the difference value between the distance between the right front wheel and the right rear wheel and the vehicle length, the difference value between the distance between the left front wheel and the right front wheel and the vehicle width and the difference value between the distance between the left rear wheel and the right rear wheel and the vehicle width are all smaller than a first set threshold value; if the first judgment result is smaller than the first set threshold, the first judgment result is passable; otherwise, the first judgment result is that the vehicle cannot pass;

the second judging module specifically includes:

the coordinate conversion unit is used for converting each coordinate in the vehicle supporting surface map into a vehicle projection coordinate system;

the map dividing unit is used for dividing the converted vehicle supporting surface map into three areas; the three regions are a first region, a second region and a third region; the second area is located in the middle position of the converted vehicle supporting surface map;

the highest point position determining unit is used for carrying out coordinate conversion on the coordinates of the second area and determining the position of the highest point according to the converted elevation information;

the second judgment unit is used for judging whether the position of the highest point is greater than or equal to the height of the vehicle chassis; if yes, the user can pass through; otherwise, the user cannot pass;

the third judging unit is used for determining a lateral gradient according to the elevation information in the first area and the third area; judging whether the lateral gradient is greater than or equal to a lateral gradient threshold value; if yes, the user can pass through; otherwise, it is not accessible.

4. The system of claim 3, wherein the unmanned vehicle trafficability characteristic determining module includes:

the projection length range determining unit is used for determining a projection length range of the vehicle length of the unmanned vehicle on a horizontal plane and a projection length range of the vehicle width on the horizontal plane according to the basic information of the unmanned vehicle and the maximum pitch angle and the maximum tilt angle allowed by the vehicle;

the system comprises an objective function construction unit, a data processing unit and a data processing unit, wherein the objective function construction unit is used for constructing an objective function by taking the minimum projection length of the unmanned vehicle and the projection length of the width of the vehicle on a horizontal plane as an objective and taking the projection length range of the length of the unmanned vehicle on the horizontal plane and the projection length range of the width of the vehicle on the horizontal plane as constraint conditions;

the optimal projection length determining unit is used for determining the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane according to the target function;

and the locating coordinates, the current pitch angle and the current inclination angle of the four tires of the unmanned vehicle are determined according to the optimal projection length of the vehicle length on the horizontal plane and the optimal projection length of the vehicle width on the horizontal plane.

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