CN114509085A - Quick path searching method combining grid and topological map - Google Patents
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- G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
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Abstract
The invention belongs to the technical field of automation, and provides a rapid path searching method combining a grid map and a topological map. The topological map is used for expressing the connectivity and accessibility of the whole environment on a large scale, has great advantages on large-scale path search, and avoids huge calculation burden brought by pixel traversal on the whole raster map. Grid maps are used to complement the lack of topological maps in path details on a small scale. Based on the idea of combining the grid map and the topological map, the method greatly reduces the calculation of pixel connectivity traversal in the grid map, obviously improves the convergence speed of the algorithm, reduces the space complexity and the time complexity, enables the real-time path search to be possible in a large-scale scene, and can meet the requirements of the functionality, the real-time performance and the integrity of the autonomous navigation of the ground mobile robot.
Description
Technical Field
The invention belongs to the technical field of automation, and particularly relates to a path searching method for a ground mobile robot.
Background
With the increasing of the intelligent demands of related industries, the ground mobile robot is widely applied to the fields of intelligent park logistics, intelligent mines, building surveying, emergency search and rescue and the like, so that the autonomous navigation capability is one of the research hotspots of the robot technology. The path search is the core of the autonomous navigation technology, and is used for generating a passable path and ensuring that the robot safely and quickly moves in the environment to complete a given specific task. According to the existing research, the mobile robot path search technology has difficulties mainly in the following three aspects: (I) how to model the environment, (II) how to reduce the sampling space, and (III) how to improve the convergence efficiency of the search algorithm.
At present, some feasible methods have been successfully realized on simulation experiments and real robots, wherein the method based on greedy search and Rapid Random Tree (RRT) has good effect. The idea of a classical greedy search algorithm, such as a and D, is to iteratively traverse and grow passable pixel points from a starting point until a target point is found. The RRT-based method is equivalent to increase the step size of an A-algorithm, and the core idea is that starting from a starting point, a random tree is iteratively grown until the random tree finds a target point, the algorithm is high in efficiency, but the randomness of the algorithm causes that a final path may not be an optimal path, and longer-time optimization is needed to enable the path to converge.
Disclosure of Invention
The invention aims to solve the problem of how to design and realize a rapid ground mobile robot path search algorithm by combining a grid map and a topological map. The invention aims to improve the existing greedy search algorithm and graph search algorithm and utilize the characteristics of the greedy search algorithm and the graph search algorithm to realize real-time path search in a large-scale environment.
The technical scheme adopted by the invention is as follows:
a quick path searching method combining a grid and a topological map is suitable for a real-time autonomous navigation task of a ground mobile robot, and comprises the following steps:
step 2, searching candidate starting edges PSE and candidate target edges PTE in the topological map obtained in the step 1 by using a grid map M;
Further, the step 2 specifically comprises the following steps:
step 2.1, extracting an obstacle pixel point set O from the grid map M, as shown in formula 1:
in the formula, width is the width of the robot motion model, x is any pixel point in the grid map M, and x isiIs an obstacle pixel point in the grid map M;
step 2.2, finding out all candidate starting edge PSE and candidate target edge PTE in the topological map, as shown in formula 2 and formula 3:
PSE=(Ea,Xa)={(e∈E,x∈e)|VT(la,e)≠none,x=VT(la,e)} (2)
PTE=(Eb,Xb)={(e∈E,x∈e)|VT(lb,e)≠none,x=VT(lb,e)} (3)
wherein E isaAnd EbSets of edges, X, representing candidate start edges and candidate target edges, respectivelyaAnd XbRepresenting a set of corresponding via points, starting point laFrom a single point of approachCorresponding candidate starting edges can be reachedlbFrom one point of approachThe corresponding candidate target edge can be reachedVT(laE) and VT (l)bAnd e) are respectively starting points laAnd end point lbVisibility detection function from edge e, its function prototype VT (x)mAnd e) is pixel point xmAnd e, see equation 4:
wherein the return value of the functionIs a distance x on the edge emNearest and xmVisual pixel dot, VT (x)m,xn) Is two pixels xmAnd xnSee equation 5:
wherein the content of the first and second substances,representing a pixel point xmAnd xnThe line segment in between.
Further, step 3 specifically includes the following steps:
step 3.1, for all candidate starting edges PSE, combining the grid map M and the visibility detection function to find all candidate starting paths Ta→GAs shown in equation 6:
in the formula (I), the compound is shown in the specification,is the t-th candidate starting edge,is thatThe corresponding passing-through point is arranged on the base,andrespectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path;representing along edge e, fromTo the edgeThe path segment of the 1 st node of (1) is an edgeA part of (a);representing along edge e, fromTo the edgeThe path segment of the 2 nd node of (1), is an edgeA part of (a);
step 3.2, for all candidate target edges pTE, combining the grid map M and the visibility detection function to find all candidate target paths TG→bAs shown in equation 7:
in the formula (I), the compound is shown in the specification,is the jth candidate target edge,is thatThe corresponding passing-through point is arranged on the base,andrespectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path;indicating a borderFrom the side 1 st node toThe path section of is an edgeA part of (a);indicating a borderFrom the side2 nd node toThe path section of is an edgeA part of (a);
in the formula (I), the compound is shown in the specification,is a connection node in a topological map GAndthe subgraph of (1) can be searched by using Dijkstra algorithm;
step 3.4, conventional candidate Path in step 3.3On the basis of (a), two cases need to be considered: (I) laAnd lbVisible, i.e. VT (l)a,lb) 1 is ═ 1; (II) edge set E of candidate starting edges PSEaEdge set E with candidate target edge PTEbThere is an intersection, i.e.Thus all candidate paths Ta→bThree cases are included as shown in equation 9:
step 3.5, selecting candidate path Ta→bOne path with the shortest medium length As a final path search result, where length (T)i) Representative route TiIs calculated using the euclidean distance.
Compared with the prior art, the invention has the following advantages:
the invention greatly reduces the calculation of pixel connectivity traversal in the grid map, avoids the randomness brought by the traditional algorithm based on fast exploration random tree, obviously improves the convergence speed of the algorithm, greatly reduces the space complexity and time complexity of the traditional method, enables the real-time path search to be possible in a large-scale scene, and can meet the requirements of the autonomous navigation of the ground mobile robot on functionality, real-time performance and integrity.
Drawings
Fig. 1 is a schematic diagram of a grid map M and a topological map G in the embodiment of the present invention.
FIG. 2 is a schematic diagram of a candidate start edge PSE and a candidate target edge PTE according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a candidate start path and a candidate target path according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating a final path search result T according to an embodiment of the present inventiona→bSchematic representation.
Detailed Description
For the purpose of illustrating the technical contents, features and effects of the invention in detail, the following detailed description is given in conjunction with the accompanying drawings.
The invention provides a rapid path searching method combining a grid map and a topological map, wherein the topological map is generated from the grid map of the environment, and the path searching method of a mobile robot is designed and realized by combining the respective advantages of the two maps. The topological map can express the connectivity and accessibility of the whole environment on a large scale, has great advantages on large-scale path search, and avoids huge calculation burden caused by pixel traversal on the whole raster map. Grid maps are used to complement the lack of topological maps in path details on a small scale, since pixel traversal is only required over a small range of the grid map. The algorithm provided by the invention is based on the idea of combining the grid map and the topological map, the calculation of pixel connectivity traversal in the grid map is greatly reduced, meanwhile, the randomness caused by the traditional algorithm based on the Rapid-exploration Random Tree (RRT) is avoided, the convergence speed of the algorithm is obviously improved, the space complexity and the time complexity of the traditional method are greatly reduced, the real-time path search in a large-scale scene becomes possible, and the requirements of the functionality, the real-time performance and the integrity of the autonomous navigation of the ground mobile robot can be met.
The steps of the present invention are described in further detail below:
Step 2, searching candidate initial edges in the topological map obtained in the step 1 by using the grid map MAnd candidate target edgesThe result is shown in fig. 2, which illustrates candidate starting edges and candidate target edges. Starting point is laEnd point is lb。As candidate starting points,is a candidate target edge. The method comprises the following substeps:
step 2.1, extracting an obstacle pixel point set O from the grid map M, as shown in formula 1:
in the formula, width is the width of the robot motion model, x is any pixel point in the grid map M, and x isiIs an obstacle pixel point in the grid map M;
step 2.2, finding out all candidate starting edge PSE and candidate target edge PTE in the topological map, as shown in formula 2 and formula 3:
PSE=(Ea,Xa)={(e∈E,x∈e)|VT(la,e)≠none,x=VT(la,e)} (2)
PTE=(Eb,Xb)={(e∈E,x∈e)|VT(lb,e)≠none,x=VT(lb,e)} (3)
wherein E isaAnd EbSets of edges, X, representing candidate start edges and candidate target edges, respectivelyaAnd XbRepresenting a set of corresponding via points, starting point laFrom a single point of approachCorresponding candidate starting edges can be reachedlbFrom a point of approachThe corresponding candidate target edge can be reachedFor example, in FIG. 3,/aPathway(s)Point to edge lbPathway(s)To the edgeVT(laE) and VT (l)bAnd e) are respectively starting points laAnd end point lbVisibility detection function from edge e, its function prototype VT (x)mAnd e) is pixel point xmAnd e, see equation 4:
wherein the return value of the functionIs a distance x on the edge emNearest and xmVisual pixel dot, VT (x)m,xn) Is two pixels xmAnd xnSee equation 5:
wherein the content of the first and second substances,representing a pixel point xmAnd xnThe line segment in between.
step 3.1, for all candidate starting edges PSE, combining the grid map M and the visibility detection function to find all candidate starting paths Ta→GAs shown in equation 6:
in the formula (I), the compound is shown in the specification,is the ith candidate starting edge,is thatThe corresponding passing-through point is arranged on the base,andrespectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path; representing along edge e, fromTo the edgeThe path segment of the 1 st node of (1) is an edgeA part of (a);representing along edge e, fromTo the edgeThe path segment of the 2 nd node of (1), is an edgeA part of (a); the result is shown in FIG. 3, the candidate start path Ta→RAGVG(left dotted line) and candidate target path TRAGVG→b(dotted right).
Step 3.2, for all candidate target edge PTEs, combining the grid map M and a visibility detection function to find all candidate target paths TG→bAs shown in equation 7:
in the formula (I), the compound is shown in the specification,is the jth candidate target edge,is thatThe corresponding passing-through point is arranged on the base,andand respectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path;indicating a borderFrom the side 1 st node toThe path section of is an edgeA part of (a);indicating a borderFrom the side2 nd node toThe path section of is an edgeA part of (a); the results are shown in FIG. 3.
in the formula (I), the compound is shown in the specification,is a connection node in a topological map GAndthe subgraph of (1) can be searched by using Dijkstra algorithm;
step 3.4, conventional candidate Path in step 3.3On the basis of (a), two cases need to be considered: (I) laAnd lbVisible, i.e. VT (l)a,lb) 1 is ═ 1; (II) edge set E of candidate starting edges PSEaEdge set E with candidate target edge pTEbThere is an intersection, i.e.Thus all candidate paths Ta→bThree cases are included as shown in equation 9:
step 3.5, selecting candidate path Ta→bOne path with the shortest medium length As a final path search result, where length (T)i) Representative path TiIs calculated using the euclidean distance. As shown in fig. 4, connect l from left to rightaAnd lbThe dotted line of (b) is the final path search result.
The above description is only an example of the present invention and is not intended to limit the present invention. Any modification, improvement or the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (3)
1. A quick path searching method combining a grid and a topological map is suitable for a real-time autonomous navigation task of a ground mobile robot, and is characterized by comprising the following steps:
step 1, extracting a simplified generalized Voronoi diagram G ═ E, V, M from a grid map M based on an improved K3M algorithmdistAs a topological map, where E is an edge, V is a node, MdistIs a distance matrix of the graph;
step 2, searching candidate starting edges PSE and candidate target edges PTE in the topological map obtained in the step 1 by using a grid map M;
step 3, using the candidate starting edge PSE and the candidate target edge PTE found in the step 2 as elicitations to search the candidate starting path Ta→GAnd candidate target path TG→b(ii) a For each pair of candidate start path and candidate target path thereinFinding connections in a topological mapAndsub-drawing ofGenerating all candidate paths Ta→bAnd taking the path with the shortest length as a result path.
2. The method for fast path search by combining a grid and a topological map according to claim 1, wherein the step 2 specifically comprises the following steps:
step 2.1, extracting an obstacle pixel point set O from the grid map M, as shown in formula 1:
in the formula, width is the width of the robot motion model, x is any pixel point in the grid map M, and x isiIs an obstacle pixel point in the grid map M;
step 2.2, finding out all candidate starting edge PSE and candidate target edge PTE in the topological map, as shown in formula 2 and formula 3:
PSE=(Ea,Xa)={(e∈E,x∈e)|VT(la,e)≠none,x=VT(la,e)} (2)
PTE=(Eb,Xb)={(e∈E,x∈e)|VT(lb,e)≠none,x=VT(lb,e)} (3)
wherein E isaAnd EbSets of edges, X, representing candidate start edges and candidate target edges, respectivelyaAnd XbRepresenting a set of corresponding via points, starting point laFrom a single point of approachCorresponding candidate starting edges can be reachedEnd point lbFrom one point of approachThe corresponding candidate target edge can be reachedVT(laE) and VT (l)bE) division ofIs respectively a starting point laAnd end point lbVisibility detection function from edge e, its function prototype VT (x)mAnd e) is pixel point xmAnd e, as shown in equation 4:
wherein the return value of the functionIs a distance x on the edge emNearest and xmVisual pixel dot, VT (x)m,xn) Is two pixels xmAnd xnThe visibility detection function in between, as equation 5:
3. The method for fast path search by combining a grid and a topological map according to claim 2, wherein step 3 specifically comprises the following steps:
step 3.1, for all candidate starting edges PSE, combining the grid map M and the visibility detection function to find all candidate starting paths Ta→GAs shown in equation 6:
in the formula (I), the compound is shown in the specification,is the t-th candidate starting edge,is thatThe corresponding passing-through point is arranged on the surface of the steel strip,andrespectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path;representing along edge e, fromTo the edgeThe path segment of the 1 st node of (1) is an edgeA part of (a);representing along edge e, fromTo the edgeThe path segment of the 2 nd node of (1), is an edgeA part of (a);
step 3.2, for all candidate target edge PTEs, combining the grid map M and a visibility detection function to find all candidate target paths TG→bAs shown in equation 7:
in the formula (I), the compound is shown in the specification,is the jth candidate target edge,is thatThe corresponding passing-through point is arranged on the base,andrespectively representThe two nodes of the network node (c),representing line segmentsThe path of the indication is such that,representing line segmentsThe path of the indication is such that,representing line segmentsThe indicated path;indicating a borderFrom the side1 st node toPath segment ofIs a sideA part of (a);indicating a borderFrom the side2 nd node toThe path section of is an edgeA part of (a);
in the formula (I), the compound is shown in the specification,is a connection node in a topological map GAndthe subgraph of (1) can be searched by using Dijkstra algorithm;
step 3.4, usual in step 3.3Rule candidate pathOn the basis of (1), two situations need to be considered: (I) laAnd lbVisual, i.e. VT (l)a,lb) 1 is ═ 1; (II) edge set E of candidate starting edges PSEaEdge set E with candidate target edge PTEbThere is an intersection, i.e.Thus all candidate paths Ta→bThree cases are included as shown in equation 9:
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Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106970614A (en) * | 2017-03-10 | 2017-07-21 | 江苏物联网研究发展中心 | The construction method of improved trellis topology semantic environment map |
CN107862738A (en) * | 2017-11-28 | 2018-03-30 | 武汉大学 | One kind carries out doors structure three-dimensional rebuilding method based on mobile laser measurement point cloud |
WO2018113451A1 (en) * | 2016-12-22 | 2018-06-28 | 沈阳美行科技有限公司 | Map data system, method for generating and using same, and application thereof |
CN108549378A (en) * | 2018-05-02 | 2018-09-18 | 长沙学院 | A kind of mixed path method and system for planning based on grating map |
CN110703747A (en) * | 2019-10-09 | 2020-01-17 | 武汉大学 | Robot autonomous exploration method based on simplified generalized Voronoi diagram |
CN111780775A (en) * | 2020-06-17 | 2020-10-16 | 深圳优地科技有限公司 | Path planning method and device, robot and storage medium |
CN112683275A (en) * | 2020-12-24 | 2021-04-20 | 哈尔滨工业大学芜湖机器人产业技术研究院 | Path planning method of grid map |
US20210333108A1 (en) * | 2018-12-28 | 2021-10-28 | Goertek Inc. | Path Planning Method And Device And Mobile Device |
-
2022
- 2022-02-10 CN CN202210123852.4A patent/CN114509085B/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018113451A1 (en) * | 2016-12-22 | 2018-06-28 | 沈阳美行科技有限公司 | Map data system, method for generating and using same, and application thereof |
CN106970614A (en) * | 2017-03-10 | 2017-07-21 | 江苏物联网研究发展中心 | The construction method of improved trellis topology semantic environment map |
CN107862738A (en) * | 2017-11-28 | 2018-03-30 | 武汉大学 | One kind carries out doors structure three-dimensional rebuilding method based on mobile laser measurement point cloud |
CN108549378A (en) * | 2018-05-02 | 2018-09-18 | 长沙学院 | A kind of mixed path method and system for planning based on grating map |
US20210333108A1 (en) * | 2018-12-28 | 2021-10-28 | Goertek Inc. | Path Planning Method And Device And Mobile Device |
CN110703747A (en) * | 2019-10-09 | 2020-01-17 | 武汉大学 | Robot autonomous exploration method based on simplified generalized Voronoi diagram |
CN111780775A (en) * | 2020-06-17 | 2020-10-16 | 深圳优地科技有限公司 | Path planning method and device, robot and storage medium |
CN112683275A (en) * | 2020-12-24 | 2021-04-20 | 哈尔滨工业大学芜湖机器人产业技术研究院 | Path planning method of grid map |
Non-Patent Citations (3)
Title |
---|
DALIN LI ET AL.: "A Multi-Type Features Method for Leg Detection in 2-D Laser Range Data", 《IEEE SENSORS JOURNAL》 * |
余等: "基于栅格地图的分层式机器人路径规划算法", 《中国科学院大学学报》 * |
张波涛等: "基于栅格-几何混合地图的移动机器人分层路径规划", 《华东理工大学学报(自然科学版)》 * |
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