CN111006652A

CN111006652A - Method for running robot close to edge

Info

Publication number: CN111006652A
Application number: CN201911328055.4A
Authority: CN
Inventors: 欧阳若愚; 洪涛; 卢雄辉; 陈诺
Original assignee: Shenzhen Wujing Intelligent Robot Co ltd
Current assignee: Shenzhen Feiyao Motor Technology Co ltd
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-04-14
Anticipated expiration: 2039-12-20
Also published as: CN111006652B

Abstract

The invention discloses a method for running a robot close to the side, which comprises the following steps: s1, generating a road network; s2, planning the track based on the road network; and S3, shifting the planned track to the edge of the road, so that the robot runs along the road edge. When the robot needs to plan the track, the track is planned according to the road network, and the track is drawn to the edge of the road, so that the method has higher efficiency, effectively reduces errors, avoids the development of necessary interactive software for setting the fixed track, and saves the development cost.

Description

Method for running robot close to edge

Technical Field

The invention relates to the technical field of robot driving path planning, in particular to a method for running a robot close to the side.

Background

With the development of mobile robot technology, the robot can move autonomously and flexibly indoors, but is less frequent outdoors, and at present, two methods are mainly used for the robot to operate outdoors, one method is to use a traditional shortest path-based trajectory planning method, and the shortest trajectory from the robot to a target point can be obtained without considering whether the robot is planned along a roadside or not. Assuming that a robot needs to reach a point a on one side of a road to a point B on the other side of the road, according to a conventional shortest distance-based trajectory planning method, a straight line trajectory from a to B is obtained, as shown in fig. 1(a), such a trajectory has a large proportion located in the center of the road, and if the robot runs along such a trajectory, the robot will run in the center of the road for a long time, which affects the traffic order of the road; in order to minimize the influence on the safety and order of the road, it is necessary to travel along the road to the point C directly opposite to the point B and then cross the road, as shown in fig. 1 (B). Note that the shaded portions in the figure are all buildings or obstacles in the map, and the blank portions are roads.

In order to solve the above problems encountered when the robot operates outdoors and reduce the influence of the robot on the traffic order, the main method is to make the robot travel along a fixed track along the roadside by setting the track in advance. The steps of such a method are:

1. after the robot is deployed, a map of a scene is obtained, two tracks for driving along a road are manually set according to the road in the map, if the robot drives to the right, two tracks are required in two directions, as shown in fig. 2, two curves are set fixed tracks, and a black arrow indicates that the robot drives to the right.

2. At the road intersection, the merging points of the side tracks of different roads need to be manually set, the number of the merging points set at the road intersection is the same as the number of the road intersections, then the merging points at the same road intersection are connected with each other, as shown in fig. 3, four roads are intersected at an intersection, the curves are respectively fixed tracks set by the

roads

1, 2, 3 and 4, 4 merging points are arranged at the intersection, each merging point is connected with two set fixed tracks, the merging points are also connected, in order to limit driving near the right side, the merging points are in one-way connection, and the connection mode is as shown in fig. 3.

3. And storing the junction points at different road intersections and the set fixed tracks among the junction points by using a graph structure in a computer.

4. When the robot receives the target point, the stored graph structure is used for planning to obtain the junction points which the robot should pass through in the process of reaching the target point, then the tracks among a series of junction points are connected to obtain the fixed track of the target point, as shown in fig. 4, the robot starts from the point A and goes to the point B, the robot firstly finds the closest point which is away from the fixed track from the current position and the closest point which is between the target point and the fixed track, then planning is carried out according to the shortest path of the graph structure to obtain the track of the robot as shown by a thick curve in fig. 4, and the effects of driving close to the side and not obstructing traffic are realized to the maximum extent.

If the conventional method of planning the shortest path based on the map is used, the planning effect is shown in fig. 5, and compared with fig. 4, the planning method takes far more time to travel in the center of the road, and the traffic is greatly hindered.

However, the existing method for driving the robot along the road still has the following disadvantages:

1. the set fixed track along the roadside is large in engineering quantity, due to the fact that the scenes of the robot in operation are different in scale, the number of roads is large under a large-scale scene, the fixed track along the roadside needs to be set for each road, and the connection mode of the tracks between different roads needs to be designed at the road junction, so that the large workload is achieved, and the robot is not beneficial to rapid deployment in a new scene.

2. The fixed track along the roadside is set through manual operation, the track set by different operators may be different, the distance from the edge of the road is different during driving, the effect of driving by the side is correspondingly influenced, and the generalization and modularization of the function of driving by the side are not facilitated.

3. The fixed track setting based on the map needs manual operation, manual calibration of whether the track meets requirements or not is needed, and adjustment is needed, so that interactive software between the map and the track and a user needs to be developed, and the development cost is increased.

In order to solve the above problems, it is necessary to develop a new method for running along the roadside, which can efficiently and quickly plan the movement trajectory of the robot, and make the trajectory deviate to the roadside, so that the robot runs along the trajectory along the roadside.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for running a robot close to the side.

In order to achieve the purpose, the invention adopts the following specific scheme:

a method for running a robot alongside comprises the following steps: s1, generating a road network; s2, planning the track based on the road network; and S3, shifting the planned track to the edge of the road, so that the robot runs along the road edge.

Preferably, the method for generating the road network in step S1 includes the steps of:

a1: the robot traverses the scene so as to establish a map and generate a map establishing track;

a2: carrying out curve fitting on the mapping track to form a mapping track curve;

a3: taking a point at every certain distance on the mapping track curve as a node of the road network;

a4: and connecting each node according to a certain method to obtain the road network.

Preferably, the mapping track generated in step a1 is generated by recording the position of the robot at regular intervals while the robot traverses the scene, so as to form a mapping track composed of a series of first discrete points.

Preferably, the mapping track curve formed in step a2 is formed by fitting a mapping track of a road repeatedly passed by the robot by using a least square method, and combining the fitted part with the part not required to be fitted to form a complete mapping track curve.

Preferably, the method for obtaining the nodes in step a3 is to divide the map into a plurality of grids with the same size, and average position coordinates are taken from the map building track in each grid, where each average position coordinate is a node.

Preferably, the method for obtaining the road network in step a4 is that a certain node is taken as a central node in a certain range, all nodes in the range are connected with the central node, if a connecting line between the certain node and the central node passes through a building on the map, the node is not taken, otherwise, the node is taken as an effective node, and each node is connected with the effective node in the same range of the node to obtain the road network.

Preferably, the method for planning a track based on a road network in step S2 is that a track to be planned is provided with a starting point and an end point, the starting point and a node closest to the starting point are connected, the end point and a node closest to the end point are connected, and a shortest path between the two nodes is planned in the road network, so as to obtain a planned operation track, which is recorded as a first track.

Preferably, the method for shifting the planned trajectory to the edge of the road in step S3 is to project the first trajectory to the same side of the road to the vicinity of the building, and the specific steps are as follows:

b1: on the first track, taking the midpoint of a track line segment between every two nodes as a starting point, emitting rays to the same side in a direction perpendicular to the direction of each track line segment, and taking the boundary of a building or a map, which is intersected with each ray for the first time after the ray is emitted, as a projected building;

b2: and dispersing the planned track in the road network into a series of second discrete points, searching points closest to each second discrete point on a boundary at a certain distance from the projected building, recording the points as projection points, and sequentially connecting the projection points to obtain a second track, wherein the second track is a roadside track along which the robot finally runs.

By adopting the technical scheme of the invention, the invention has the following beneficial effects:

the method mainly aims at the defects of large engineering quantity and difficult general modularization of the set fixed track, obtains the road network automatically generated by a computer program while acquiring the map of a scene, avoids manual operation, and ensures the universality and modularization of functions; when the robot needs to plan the track, the track is planned according to the road network, and the track is drawn close to the edge of the road, the whole process is completely controlled by a computer program, manual intervention is not needed, the efficiency is high, the error is effectively reduced, the development of necessary interactive software for setting the fixed track is avoided, and the development cost is saved.

Drawings

Fig. 1 is a basic schematic diagram of a prior art shortest path planning-based system;

FIG. 2 is a schematic diagram of a prior art ride along a roadside fixed track;

FIG. 3 is a schematic diagram of a roadside fixed-track junction according to the prior art;

FIG. 4 is a prior art trajectory diagram for following a roadside fixed trajectory;

FIG. 5 is a prior art shortest path planning based trajectory graph;

FIG. 6 is a schematic diagram of a mapping trajectory according to the present invention;

FIG. 7 is a schematic diagram of a mapping trajectory curve according to the present invention;

FIG. 8 is a schematic view of a map grid according to the present invention;

FIG. 9 is a schematic view of a node of a road network according to the present invention;

FIG. 10 is a schematic view of an effective node of a road network according to the present invention;

FIG. 11 is a schematic view of a road network according to the present invention;

FIG. 12 is a schematic diagram of a first trace of the present invention;

FIG. 13 is a first trace projection diagram according to the present invention;

FIG. 14 is a schematic view of a proxel according to the present invention;

FIG. 15 is a diagram illustrating a second trace according to the present invention.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Referring to fig. 11, 12 and 15, the present invention provides a method for a robot to run alongside, comprising the steps of: s1, generating a road network; s2, planning the track based on the road network; and S3, shifting the planned track to the edge of the road, so that the robot runs along the road edge.

The method for generating the road network in the step S1 includes the steps of:

Referring to fig. 6, the method for generating the mapping trajectory in step a1 is that the robot traverses the entire scene from point a to point B, the traversed trajectory is shown as a thin curve in the diagram, and when the robot traverses the scene, the position of the robot is recorded at regular intervals (for example, 0.1 second), so as to form the mapping trajectory composed of a series of first discrete points.

Referring to fig. 6 and 7, the method for forming the mapping track curve in step a2 is that, in the process of traversing the map by the robot, some roads may pass more than once, a plurality of segments of mapping tracks repeatedly passing through one road are proposed, a plurality of discrete points are fitted into one line segment by a straight line fitting method, the straight line fitting method is a least square method, and the specific steps are as follows:

(1) taking a series of discrete points out as fitting data, wherein the data are respectively (x)₁，y₁)，(x₂，y₂)，...，(x_n，y_n)

(2) The fitting equation given the assumption is:

y＝ax+b

(3) the sum of the squares of the distances from each point to the line is calculated:

(4) the straight line fit is such that the sum of the squares of the distances from each point to the straight line is minimized, so the partial derivative of a and b is taken to be 0 for the equation:

(5) solving the parameters a and b in the fitting equation as:

by the method, a plurality of map building track points with relatively close distances are taken out for fitting, as shown in fig. 7(a), the map building tracks with relatively close distances are removed from the original map building tracks, the map building tracks are processed by curve fitting to be thick line segments, other thin curves are the original map building tracks left after removal, and the two are combined to obtain the processed complete map building track curve shown by the curve in fig. 7 (b).

Referring to fig. 8 to 9, the method for obtaining nodes in step a3 is to divide the map into a plurality of grids with the same size, as shown in fig. 8, average position coordinates are taken from the map building track in each grid, each average position coordinate is a node, as shown in fig. 9, there is a node in each grid on the road.

Referring to fig. 10 to 11, the method for obtaining the road network in step a4 is to take a certain node as a central node in a certain range, connect all nodes in the range with the central node, as shown in fig. 10, take a dark-color node as the central node, search in a circle with a dark-color node as a center and 1.5 times of grid side length as a radius, find a light-color node that is a node that may need to be connected, if a line segment (a dotted line segment) between the light-color node and the dark-color node passes through the building, connect the light-color node (an effective node) that the line segment (a solid line segment) does not pass through the building with the dark-color node, and perform the above operations on each node to obtain the road network schematic diagram shown in fig. 11.

Referring to fig. 12, the method for planning a track based on a road network in step S2 is that a track to be planned is provided with a starting point a and an end point B, a node 1 connected to the starting point a and closest to the starting point a, and a node 2 connected to the end point B and closest to the end point B, and a shortest path between the node 1 and the node 2 is planned in the road network, so as to plan a running track from the starting point a to the end point B, which is denoted as a first track.

Referring to fig. 13 to 15, the method for shifting the planned trajectory to the edge of the road in step S3 is to project the first trajectory to the same side of the road to the vicinity of the building, and the specific steps are as follows:

b1: referring to fig. 13, the first trajectory is a dotted line, the trajectory between every two nodes is divided into one segment, the first trajectory is divided into 9 segments in total, a ray is emitted to the same side (for example, to the right side or to the left side uniformly) perpendicular to the direction of each segment with the midpoint of each segment as a starting point, the ray direction is as shown by an arrow, and the building or map boundary that each ray intersects with after being emitted for the first time is used as a projected building, such as building 1, building 2, and building 3 in fig. 13.

B2: referring to fig. 14, the first trajectory is discretized into a series of second discrete points, the distance between every two second discrete points may be 0.1 meter, a point closest to each second discrete point is searched on a boundary at a certain distance from the projected building and is recorded as a projection point, each projection point corresponds to the second discrete point one by one, as shown in fig. 15, each projection point is sequentially connected to obtain a second trajectory (a thick solid line in the drawing), and the second trajectory is a roadside trajectory along which the robot finally runs.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A method for running a robot alongside is characterized by comprising the following steps:

s1, generating a road network;

s2, planning the track based on the road network;

and S3, shifting the planned track to the edge of the road, so that the robot runs along the road edge.

2. The method for the robot to run alongside according to claim 1, wherein the method for generating the road network in step S1 comprises the steps of:

3. The method for the robot to run alongside according to claim 2, wherein the method for generating the mapping track in step a1 is as follows:

when the robot traverses a scene, the position of the robot is recorded at regular intervals, so that a mapping track consisting of a series of first discrete points is formed.

4. A method for robot side-by-side operation according to claim 3, wherein the method for forming the mapping trajectory curve in step a2 is as follows:

and (3) carrying out curve fitting on the mapping track of a certain section of road repeatedly passed by the robot by using a least square method, and combining the fitted part and the part not required to be fitted to form a complete mapping track curve.

5. The method for the robot to run alongside according to claim 4, wherein the method for obtaining the nodes in step A3 is as follows:

dividing the map into a plurality of grids with the same size, and averaging position coordinates of the map building track in each grid, wherein each average position coordinate is a node.

6. The method for robot to run alongside according to claim 5, wherein the method for obtaining the road network in step A4 is:

and taking a certain node as a central node in a certain range, connecting all nodes in the range with the central node, if a connecting line of the certain node and the central node passes through a building on a map, not taking the node, otherwise, taking the node as an effective node, and connecting each node with the effective node in the same range of the node to obtain the road network.

7. The method for the robot to run alongside according to claim 6, wherein the method for planning the trajectory based on the road network in step S2 is as follows:

the track to be planned is provided with a starting point and an end point, the starting point and the node closest to the starting point are connected, the end point and the node closest to the end point are connected, the shortest path between the two nodes is planned in the road network, and therefore the planned running track is obtained and recorded as a first track.

8. The method for the robot to move alongside according to claim 7, wherein the method for shifting the planned trajectory to the edge of the road in step S3 is to project the first trajectory to the same side of the road to the vicinity of the building, and the specific steps are as follows: