Farm operation path planning method and application

Abstract

The invention belongs to a vehicle path planning technology, mainly relates to the field of agricultural vehicle path planning, and particularly relates to a farm operation path planning method and application. Spatial analysis is carried out on the basis of a plot boundary, a target strip-shaped obstacle boundary and a non-target obstacle boundary which are obtained through pre-surveying and mapping, according to strip-shaped geometrical characteristics of a target strip-shaped obstacle, the long edge of the target strip-shaped obstacle is extracted as a boundary to be operated, and the outer side areas of the short edges at the two ends serve as turning areas; and generating a global path for traversing the to-be-operated boundary of the target strip-shaped obstacle in a reciprocating manner and avoiding a non-target obstacle in a specified direction until the last target strip-shaped obstacle in the specified direction is traversed. According to the method, the strip-shaped geometrical characteristics of the target strip-shaped obstacles are fully utilized, the redundancy rate and the omission rate of the operation path are reduced, the quality and the efficiency of farm unmanned operation are improved, meanwhile, the algorithm efficiency is greatly improved by using a pure geometric algorithm, and the global operation path traversing each specified target strip-shaped obstacle can be quickly generated.

Description

Technical Field

[0001] The present invention belongs to vehicle path planning technology, mainly relates to the field of agricultural vehicle path planning, and in particular to a farm operation path planning method and application. Background Art

[0002] Farm operation path planning is one of the key links of unmanned operation, especially farm unmanned operation. In the farm unmanned operation system, it is necessary to generate a global operation path based on farm information as the input of the control layer to guide the operation of the operation crawler vehicle. For the operation task, generating a reasonable and complete operation path in a complex farm environment is one of the important prerequisites to ensure the quality and efficiency of farm unmanned operation.

[0003] Most of the existing farm operation path planning is aerial three-dimensional path planning for drones, and there are relatively few path planning for ground vehicles. In the path planning for farm ground operation vehicles, there are currently two main methods, one is the local obstacle avoidance path planning method based on environmental perception, and the other is the global path planning method based on raster analysis. Among them, the local planning method based on environmental perception mainly uses lidar or camera to obtain local environmental information around the operation vehicle, and extracts the passable area through point cloud analysis or image segmentation, so as to generate the current local path in the passable area. Although this type of method does not require the farm environment to be mapped in advance, the vehicle itself needs to be equipped with additional sensors and computing units with higher computing power, which is costly. In addition, this local planning itself does not take into account the global plot boundaries and target strip obstacle distribution characteristics, and it is easy to generate redundant paths, affecting the quality and efficiency of farm operations.

[0004] Different from the local planning methods mentioned above, the global farm operation path planning method based on grid analysis requires mapping the farm in advance, obtaining the boundaries of the plots and the boundaries of the target strip obstacles, and converting them into grid maps. Based on the grid maps, A*, ant colony and other search algorithms are used to obtain the optimal obstacle avoidance operation path between the given starting point and the end point. Although this type of method takes into account the global information of the farm and does not generate redundant paths, it is easy to omit because the operation path is simplified to an obstacle avoidance path between two points, resulting in some operation targets (such as fruit trees) that are not on the optimal obstacle avoidance path being omitted. In addition, the use of heuristic search algorithms also makes this type of method less efficient. Summary of the invention

[0005] In order to solve the problems that existing farm operation path planning methods are prone to redundancy or omissions, and have high hardware requirements leading to increased costs, the present invention provides a geometric algorithm based on spatial analysis to generate a global farm operation path, specifically a farm operation path planning method and application.

[0006] The present invention provides the following technical solutions:

[0007] A farm operation path planning method comprises the following steps:

[0008] S100: Farm information acquisition: The farm information includes the land boundary, the target strip obstacle boundary and the non-target obstacle boundary; wherein, bd orchard is the land parcel boundary, is the boundary of n target strip obstacles, are m non-target obstacle boundaries;

[0009] S200: generating a job strip: specifically including:

[0010] S201: Target strip obstacle boundary segmentation: Divide it into four parts They represent the two long boundaries and two short boundaries of the target strip obstacle respectively. The specific segmentation method is to calculate them in sequence. The slope k of the line segment formed by each two adjacent points in j , then the slope change will have the first four jumps, these jump points are the dividing points between the long side and the short side of the long target strip obstacle polygon. The closed loop is broken into four broken line segments to complete the segmentation;

[0011] S202: Operation baseline generation: First obtain the first target strip obstacle The outer long side Given that the minimum distance between the working vehicle's path and the target strip obstacle during normal operation is d min , then Outward deviation d min Get the first job baseline For the middle area with target strip obstacles on both sides, obtain each adjacent set of target strip obstacles The adjacent long side and And calculate the medians of these two sets of long sides The specific method is: 1) Get as well as The two outermost endpoints along the direction of the long side extension line 2) There are k1+1 long edges, If there are k2-k1 long sides, the left and right pairing will generate max(k1+1,k2-k1) non-intersecting midlines, where the outer endpoints of the two outermost midlines are 3) Connect all the midlines in order to get Finally, get the last target obstacle. The outer long side Shift it outwards min Get the last job baseline

[0012] S203: Operation baseline obstacle avoidance processing: first remove the non-target obstacle boundary With d min Expand and recycle to determine the operation baseline After the expansion Check whether the polygons intersect. If they do intersect but are not tangent, calculate the intersection point of the two polygons and obtain The shorter side between the two intersection points, and Fusion to obtain the final obstacle avoidance operation strip

[0013] S300: Working strip connection: Connect each strip based on the reciprocating law Generate a turn-around route.

[0014] Preferably, in the above S300, the turning path is any one of a straight line connection path, an arc turning path or a light bulb turning path.

[0015] Preferably, in the above S300, e) for adjacent operating strips and Target strip obstacles sandwiched between strips Both ends of are connectable regions, and the initial connection region is determined according to the specified clockwise / counterclockwise direction combined with the strip sorting;

[0016] f) Determine whether there is any inconsistency in the initial connection area and If there is a collision line, calculate the collision line with and The straight line formed by the two intersection points is the connecting line

[0017] g) If there is no straight line in the initial connection area that does not cause collision, change the initial specified direction, change the operation direction from clockwise / counterclockwise to counterclockwise / clockwise, select another connectable area, and repeat f);

[0018] h) If there is no collision-free line between the two connectable areas, the path planning is completed.

[0019] Preferably, in S100, the farm information is preprocessed, and the preprocessing step specifically includes:

[0020] a) Check the input bd orchard , as well as Check whether the starting point and end point of each boundary array are the same. If they are not the same, add the starting point coordinate to the end of the boundary array to form a closed loop;

[0021] b) When bd orchard , as well as After all the boundaries in are closed, determine whether each closed boundary has self-intersection. If so, remove the small closed loop formed by the self-intersection, and the remaining large closed loop coordinate set is used as the final boundary array;

[0022] c) Loop check bd orchard and The geometric relationship of The polygon is completely in bd orchard If the polygon is inside, then it is normal; if With bd orchard If there is an intersection, then according to Cut bd orchard , remove With bd orchard Overlay part to form a new plot boundary and delete the

[0023] d) Loop check bd orchard and The geometric relationship between bd orchard The polygon contains The polygon formed is normal; if With bd orchard If there is intersection, cut The polygons formed only retain those in bd orchard The part inside the polygon.

[0024] An application of a farm operation path planning method, running a farm operation path planning method as described in any of the above, is used for farm operation path planning.

[0025] Preferably, the farm operation is a farm operation.

[0026] An automatic driving agricultural machine, comprising:

[0027] Memory for storing computer programs;

[0028] A processor is used to implement a farm operation path planning method as described in any of the above items when executing the computer program.

[0029] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements a farm operation path planning method as described in any one of the above items.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention performs spatial analysis based on the pre-surveyed plot boundaries, target strip obstacle boundaries and non-target obstacle boundaries, extracts the long side of the target strip obstacle as the boundary to be operated according to the strip geometric characteristics, and uses the outer areas of the short sides at both ends as the turning areas, and generates a global path that traverses the target strip obstacle boundary to be operated and avoids non-target obstacles in the specified direction from the starting point until the last target strip obstacle in the specified direction is traversed. The present invention makes full use of the strip geometric characteristics of the target strip obstacle, reduces the redundancy rate and omission rate of the operation path, improves the quality and efficiency of unmanned operations on the farm, and uses a pure geometric algorithm to greatly improve the efficiency of the algorithm, and can quickly generate a global operation path that traverses each specified target strip obstacle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0032] Figure 1 is a schematic diagram of a flow chart of an embodiment of the present invention;

[0033] Figure 2 Schematic diagram of trajectory generation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] like Figure 1-2 As shown:

[0036] The content of the present invention mainly includes three parts: farm information preprocessing, operation strip generation and operation strip connection. The farm information includes the boundary of the plot, the boundary of the target strip obstacle and the boundary of the non-target obstacle. The farm information preprocessing mainly includes the topological inspection and correction of the three types of boundaries; the operation strip generation part includes the three steps of target strip obstacle boundary segmentation, operation baseline generation and baseline obstacle avoidance processing; the operation strip connection is to generate the U-turn connection line of the operation strip in the outer area of ​​both ends of the target strip obstacle. The target strip obstacle here can be a forest belt, for example.

[0037] 1. Farm information preprocessing

[0038] In the farm information preprocessing part, it is necessary to perform topological correction and intersection processing on the land boundary, target strip obstacle boundary and non-target obstacle boundary to reduce the complexity of the subsequent algorithm input data, filter unnecessary intersection relationships in advance, and avoid abnormal results that may appear in subsequent geometric operations. The preprocessing steps specifically include the following points, among which, bd orchard is the land parcel boundary, is the boundary of n target strip obstacles, are the boundaries of m non-target obstacles:

[0039] a) Check the input bd orchard , as well as Check whether the starting point and end point of each boundary array are the same. If they are not the same, add the starting point coordinate to the end of the boundary array to form a closed loop;

[0040] b) When bd orchard , as well as After all the boundaries in are closed, determine whether each closed boundary has self-intersection. If so, remove the small closed loop formed by the self-intersection, and the remaining large closed loop coordinate set is used as the final boundary array;

[0041] c) Loop check bd orchard and The geometric relationship of The polygon is completely in bd orchard If the polygon is inside, then it is normal; if With bd orchard If there is an intersection, then according to Cut bd orchard , remove With bd orchard Overlay part to form a new plot boundary and delete the

[0042] d) Loop check bd orchard and The geometric relationship between bd orchard The polygon contains The polygon formed is normal; if With bd orchard If there is intersection, cut The polygons formed only retain those in bd orchard The part inside the polygon.

[0043] 2Job strip generation

[0044] For bd orchard , as well as After preprocessing, the operation strips are generated. In the farm, the distribution of target strip obstacles is presented as a group of approximately parallel long polygons, and the long side of the long polygon is the boundary to be operated. Therefore, in addition to generating operation strips along the long side outside the first and last target strip obstacles, the main operation strips are generated between two adjacent target strip obstacles, and the target strip obstacles on both sides are operated at the same time. The generation of the operation strip specifically includes three steps: target strip obstacle boundary segmentation, operation baseline generation, and baseline obstacle avoidance processing.

[0045] In the target strip obstacle boundary segmentation part, It needs to be divided into four parts They represent the two long boundaries and two short boundaries of the target strip obstacle respectively. The specific segmentation method is to calculate in sequence The slope k of the line segment formed by each two adjacent points in j , then the slope change will have the first four jumps, these jump points are the dividing points between the long side and the short side of the long target strip obstacle polygon. The closed loop is broken into four broken line segments, and the segmentation can be completed by combining length judgment, etc. The length judgment is to determine which two are long sides and which two are short sides.

[0046] In the baseline generation part, first obtain the first target obstacle strip The outer long side Given that the minimum distance between the working vehicle's path and the target strip obstacle during normal operation is d min , then Outward deviation d min Get the first job baseline For the middle area with target strip obstacles on both sides, obtain each adjacent set of target strip obstacles The adjacent long side and And calculate the medians of these two sets of long sides The specific method is: 1) Get as well as The two outermost endpoints along the direction of the long side extension line 2) There are k1+1 long edges, If there are k2-k1 long sides, the left and right pairing will generate max(k1+1,k2-k1) non-intersecting midlines, where the outer endpoints of the two outermost midlines are 3) Connect all the midlines in order to get Finally, get the last target obstacle. The outer long side Shift it outwards min Get the last job baseline

[0047] Finally, after all the operation baselines are generated, baseline obstacle avoidance processing is required. The specific processing process is to first remove the non-target obstacle boundaries. With d min Expand and recycle to determine the operation baseline After the expansion Check whether the polygons intersect. If they do intersect but are not tangent, calculate the intersection point of the two polygons and obtain The shorter side between the two intersection points, and Fusion to obtain the final obstacle avoidance operation strip

[0048] 3Job strip connection

[0049] In the job stripe that generates the boot job After that, each line needs to be connected based on the reciprocating rule. Generate a turning path. Since the present invention is aimed at working crawler vehicles, a straight line connection path can be directly generated. If it is other types of working vehicles, such as those that conform to the Ackerman steering model, they can also be connected using arc turning or light bulb turning paths. In the process, in addition to the basic reciprocating law, it is also necessary to consider and bd orchard and The influence of the relative position relationship on the connection order and stripe traversal direction is as follows:

[0050] e) For adjacent working strips and Target strip obstacles sandwiched between strips Both ends of are connectable regions, and the initial connection region is determined according to the specified clockwise / counterclockwise direction combined with the strip sorting;

[0051] f) Determine whether there is any inconsistency in the initial connection area and bd orchard If there is a collision line, calculate the collision line with and The straight line formed by the two intersection points is the connecting line

[0052] g) If there is no straight line in the initial connection area that does not cause collision, change the initial specified direction, change the operation direction from clockwise / counterclockwise to counterclockwise / clockwise, select another connectable area, and repeat f);

[0053] h) If there is no collision-free line between the two connectable areas, the path planning is completed.

[0054] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0055] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A farm operation path planning method, characterized in that: The following steps are involved: S100: Farm information acquisition: The farm information includes the land boundary, the target strip obstacle boundary and the non-target obstacle boundary; wherein, bd orchard is the land parcel boundary, is the boundary of n target strip obstacles, are m non-target obstacle boundaries; S200: generating a job strip: specifically including: S201: Target strip obstacle boundary segmentation: Divide it into four parts They represent the two long boundaries and two short boundaries of the target strip obstacle respectively. The specific segmentation method is to calculate them in sequence. The slope k of the line segment formed by each two adjacent points in j , then the slope change will have the first four jumps, these jump points are the dividing points between the long side and the short side of the long target strip obstacle polygon. The closed loop is broken into four broken line segments to complete the segmentation; S202: Operation baseline generation: First obtain the first target strip obstacle The outer long side Given that the minimum distance between the working vehicle's path and the target strip obstacle during normal operation is d min , then Outward deviation d min Get the first job baseline For the middle area with target strip obstacles on both sides, obtain each adjacent set of target strip obstacles The adjacent long side and And calculate the medians of these two sets of long sides The specific method is: 1) Get as well as The two outermost endpoints along the direction of the long side extension line 2) There are k1+1 long edges, If there are k2-k1 long sides, the left and right pairing will generate max(k1+1,k2-k1) non-intersecting midlines, where the outer endpoints of the two outermost midlines are 3) Connect all the midlines in order to get Finally, get the last target obstacle. The outer long side Shift it outwards min Get the last job baseline S203: Operation baseline obstacle avoidance processing: first remove the non-target obstacle boundary With d min Expand and recycle to determine the operation baseline After the expansion Check whether the polygons intersect. If they do intersect but are not tangent, calculate the intersection point of the two polygons and obtain The shorter side between the two intersection points, and Fusion to obtain the final obstacle avoidance operation strip S300: Working strip connection: Connect each strip based on the reciprocating law Generate a turning route.

2. A farm operation path planning method according to claim 1, characterized in that: In the above-mentioned S300, the turning path is any one of a straight line connection path, an arc turning path or a light bulb turning path.

3. A farm operation path planning method according to claim 1, characterized in that: In the S300, e) For adjacent working strips and Target strip obstacles sandwiched between strips Both ends of are connectable areas. The specified clockwise / counterclockwise direction is combined with the strip sorting to determine the initial connection area; f) Determine whether there is any inconsistency in the initial connection area and bd orchard If there is a collision line, calculate the collision line with and The straight line formed by the two intersection points is the connecting line g) If there is no straight line in the initial connection area that does not cause collision, change the initial specified direction, change the operation direction from clockwise / counterclockwise to counterclockwise / clockwise, select another connectable area, and repeat f); h) If there is no collision-free line between the two connectable areas, the path planning is completed.

4. A farm operation path planning method according to claim 1, characterized in that: In the above-mentioned S100, the farm information is preprocessed, and the preprocessing step specifically includes: a) Check the input bd orchard , as well as Check whether the starting point and end point of each boundary array are the same. If they are not the same, add the starting point coordinate to the end of the boundary array to form a closed loop; b) When bd orchard , (i=1,2,...,n) and After all the boundaries in (i=1,2,...,m) are closed, determine whether each closed boundary has self-intersection. If so, remove the small closed loop formed by the self-intersection, and the remaining large closed loop coordinate set is used as the final boundary array; c) Loop check bd orchard and The geometric relationship of The polygon is completely in bd orchard If the polygon is inside, then it is normal; if With bd orchard If there is an intersection, then according to Cut bd orchard , remove With bd orchard Overlay part to form a new plot boundary and delete the d) Loop check bd orchard and The geometric relationship between bd orchard The polygon contains The polygon formed is normal; if With bd orchard If there is intersection, cut The polygons formed only retain those in bd orchard The part inside the polygon.

5. An application of a farm operation path planning method, characterized in that: A farm operation path planning method as described in any one of claims 1 to 4 is run for farm operation path planning.

6. An automatic driving agricultural machine, characterized in that: include: Memory for storing computer programs; A processor, used to implement a farm operation path planning method as described in any one of claims 1 to 4 when executing the computer program.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements a farm operation path planning method as described in any one of claims 1 to 4.

8. The application of a farm operation path planning method according to claim 5, characterized in that: The farm operation described is orchard plant protection.

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