CN116300925A

CN116300925A - Paying-off robot and path finding method

Info

Publication number: CN116300925A
Application number: CN202310257758.2A
Authority: CN
Inventors: 朱怀波; 李有洪; 刘文雅
Original assignee: Chongqing Mingyuehu Intelligent Technology Development Co ltd
Current assignee: Chongqing Mingyuehu Intelligent Technology Development Co ltd
Priority date: 2023-03-16
Filing date: 2023-03-16
Publication date: 2023-06-23

Abstract

The utility model discloses a paying-off robot and a path finding method, and belongs to the technical field of robot path planning and path following. The method comprises paying-off path planning and path following based on the planned planning path. The paying-off path planning comprises path planning of dining areas and path planning among lofting graphs in the dining areas and path planning in the lofting graphs. Path following includes straight line mode and curved line mode. According to the utility model, the field to be drawn is divided into a plurality of dining areas, an optimal path for paying off is found through path planning, and the line is drawn according to the optimal path, so that the problem of low efficiency caused by manual line drawing is avoided. And the path following is divided into a linear mode and a curve mode, so that the following precision is ensured to the greatest extent.

Description

Paying-off robot and path finding method

Priority application

This application will be the basis of priority for subsequent patent applications including, but not limited to, chinese patent application, PCT application, foreign application based on paris convention.

Technical Field

The utility model belongs to the technical field of robot path planning and path following, and particularly relates to a method for planning and following a paying-off robot path and a paying-off robot adopting the method for planning and following the path.

Background

In house decoration and fitment construction, especially in some restaurants with specific subjects, in most cases, advanced plane layout design is performed in advance by two-dimensional or three-dimensional design software such as CAD, etc., and then a simulated effect diagram is seen. However, the actual installation will often have a certain gap from the expected effect, and certain trouble is inevitably brought to the decoration design and construction. For example, it is designed to find a decoration practical to place there, but when installed, it is found that the place where it is may be a limitation to the activities of the diner, and since the decoration is not usually randomly placed. Therefore, in order to avoid the problem that when decoration is designed, a conflict is not detected between an article and other articles or between the use of activities of diners and the like, and the conflict is not detected until the decoration is finished, and the cost is increased because the article is redesigned and even the decoration is changed, people choose to put each article in advance, namely according to the following formula 1:1 on walls and floors, and depicts a schematic. Currently, for the laying-out on the ground, the corresponding laying-out frame is usually manually attached to the ground by means of an adhesive tape. For example, a loft frame of a dining table, a dining chair, a cabinet, a decoration and the like is stuck on the ground by an adhesive tape.

With the continuous development and popularization of construction engineering technology and computer instrument technology, paying-off robots are increasingly used for assisting building construction, decoration and the like. For example, the paying-off robot is used for drawing a lofting picture frame of each article, such as a home, a modeling piece and the like, so that whether the prior design has no condition which is inconsistent with the field size can be assisted.

However, for decoration of some large restaurants, dining halls or large restaurants, compared with common home decoration, since the interior of the large restaurants, dining halls, cabinets and the like is mostly dining tables, dining chairs and cabinets, and the number of the large restaurants, dining halls and the like is large, and the ground arrangement is relatively dense, how to efficiently draw a lofting picture frame of each dining table, dining chair and the like on the ground by means of a paying-off robot is a problem to be solved.

Disclosure of Invention

The invention aims to provide a paying-off robot and a path-finding method thereof, which solve or relieve at least one problem to a certain extent and can improve the efficiency of a large number of lofting patterns drawn on a large-area ground to a certain extent.

In order to solve the technical problems, the invention adopts the following technical scheme: the paying-off robot path-finding method comprises paying-off path planning and path following based on a planned path obtained by planning, wherein the paying-off path planning step comprises the following steps:

Dividing a site to be paid out in a basic drawing into a plurality of dining areas in advance, wherein each dining area is formed by connecting each dining table and a peripheral dining chair thereof by using straight line segments or arcs in units of dining tables to form independent lofting figures to be drawn; all straight line segments or arcs in the lofting graph are directly or indirectly connected;

reading the lofting graph needing to be drawn in the basic drawing;

searching the closest point with the shortest distance to the initial position of the paying-off robot in all lofting graphs, and taking the closest point as a path starting point of all line segments to be drawn in the lofting graphs where the paying-off robot traverses the closest point;

after traversing all line segments to be drawn in the lofting graph, the paying-off robot searches for the next closest point with the shortest distance to the current position of the paying-off robot in a dining area where the lofting graph is located, takes the next closest point as a path starting point in the next lofting graph where the next closest point is located, and traverses all line segments to be drawn in the next lofting graph; repeating the steps until obtaining the line segments to be drawn in all lofting graphs in the dining area, searching for the next nearest point with the shortest distance to the current position of the paying-off robot, wherein the next nearest point belongs to other dining areas, repeating the steps until traversing the line segments to be drawn of all lofting graphs in all dining areas, and finally obtaining a planning path;

The method for carrying out path following based on the planned path obtained by planning comprises the following steps:

identifying the type of the next road section to be travelled by the paying-off robot;

if the line is a straight line section, setting a following point on the planned path for the paying-off robot based on an initial forward looking distance; then, the paying-off robot travels toward the following point and advances the following point during travel so that the initial forward looking distance is maintained between the following point and the paying-off robot;

if the curvature of the next road section is changed, setting a curvature change starting point as a following point, stopping advancing the following point, then driving to the following point, adjusting the steering angle and the forward looking distance of the paying-off robot based on the new curvature after the curvature change starting point is reached, and setting a new following point on a planning path based on the adjusted forward looking distance so as to continue driving according to the planning path; if the steering angle and the initial forward looking distance of the paying-off robot are not changed based on the curvature of the next road section, setting a following point on a planned path based on the adjusted initial forward looking distance, then driving to the following point, and keeping the forward looking distance with the following point in the driving process;

Judging whether an inflection point appears in the forward looking distance or not in the driving process, if so, setting the inflection point as a following point, and stopping pushing the following point;

and the paying-off robot runs towards the inflection point, stops running after reaching the inflection point, and sets a following point on the planned path again according to the initial forward looking distance after rotating in situ by a corresponding angle according to the path included angle at the inflection point, and runs and advances the following point according to the following point.

Further, the step of planning the path of the paying-off robot in the lofting graph includes: and the paying-off robot starts from the path starting point in the lofting graph, runs to the end point with the shortest path between the path starting point and the path starting point, draws a line, runs along the next end point with the shortest path connected with the end point after drawing the line, and draws the line until all the line segments to be drawn in the lofting graph are drawn.

Further, in the running process, the paying-off robot records each crossing passing by, wherein the crossing is an end point connected with three or more line segments; and when the paying-off robot runs to the end of the path, the paying-off robot rolls back to the last intersection.

Further, when the nearest point of the lofting graph, which is shortest to the current position path of the paying-off robot, comprises any point and a plurality of endpoints on at least one line segment, the paying-off robot selects the endpoint which is read first as a path starting point in the lofting graph according to the reading sequence of the endpoints.

Further, the step of finding the closest point having the shortest distance from the start position of the paying-off robot includes:

acquiring point coordinates of the initial position of the paying-off robot;

traversing coordinates of all points in the lofting graph without drawing lines;

calculating the distance from the initial position to all points in the lofting graph without drawing the line by using the point coordinates of the initial position and the coordinates of all points in the lofting graph without drawing the line;

and selecting the point with the shortest distance from the initial position in the lofting graph as the nearest point.

The method for setting the steering angle of the robot through planning the curvature of the path comprises the following steps: using the formula

Calculating a steering angle of the robot, wherein delta is the steering angle of the robot, L is the wheelbase of the robot, and L _d For forward looking distance, α is the angle of orientation of the following point.

Further, the corresponding relation between the curvature of the next road section and the forward looking distance is a preset value.

Further, the routing method of the paying-off robot further comprises the following steps: when the paying-off robot draws lines in the current dining area, judging that the average distance between lofting graphs in the current dining area isIf not, the current running speed is reduced according to a preset first speed increment V1; otherwise, the current driving speed is increased according to a preset second speed increment V1, wherein V ₁ ＝K ₁ ﹡ΔV，V ₂ ＝K ₂ ﹡ DeltaV, and K ₁ ＜K ₂ DeltaV is the incremental speed.

Still further, the routing method of the paying-off robot further comprises the following steps: when the paying-off robot runs in a current dining area, acquiring the density rho of the lofting graph in the current dining area in advance, judging whether the density rho is larger than a preset density threshold value, and if so, judging that the speed increment is K ₃ ﹡ DeltaV; otherwise, the speed increment is K ₄ ﹡ DeltaV; wherein K is ₃ ＜K ₄ 。

Still further, the routing method of the paying-off robot further comprises the following steps: when the paying-off robot finishes drawing a current lofting graph, judging whether the distance between the next lofting graph to be drawn and the current lofting graph is larger than a second preset interval threshold value, if so, reducing the current running speed according to a preset third speed increment V3; otherwise, the current driving speed is increased according to a preset fourth speed increment V4, wherein V ₃ ＝K ₅ ﹡ΔV，V ₄ ＝K ₆ ﹡ DeltaV, and K ₅ ＜K ₆ DeltaV is the incremental speed.

The invention also provides a paying-off robot, which adopts the path finding method to draw lines when the paying-off robot is used for decoration.

The invention has the advantages that:

according to the invention, the to-be-paid-off site is divided into a plurality of dining areas, regional line drawing is performed, and line drawing of the next dining area is performed after line drawing in one dining area is completed, so that low line drawing efficiency caused by overlong return path is avoided.

In the invention, by planning the path in advance, for example, in the same dining area, adopting the principle of nearest route, after reaching the starting point of the path on one lofting graph and completing the corresponding lofting graph, searching the next nearest point closest to the current position, namely searching the next graph needing to be drawn closest to the current position, and then searching the optimal path from the nearest point to draw lines so as to draw the lofting graph, namely carrying out path optimization in the lofting graph, carrying out path optimization among the lofting graphs, and carrying out path optimization in the dining area, thereby improving the line drawing efficiency.

In the invention, the path is divided into a straight line mode and a curve mode, and the steering angle and the forward looking distance are adjusted according to the curvature, so that deviation from a planned path caused by drift in the following process is avoided, and the following precision is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale. It will be apparent to those of ordinary skill in the art that the drawings in the following description are of some embodiments of the invention and that other drawings may be derived from these drawings without inventive faculty.

FIG. 1 is a flow chart of path planning in accordance with an exemplary embodiment of the present invention;

FIG. 2 is a flow chart of path following in accordance with an exemplary embodiment of the present invention;

FIG. 3a is an exemplary diagram of a robot's corresponding graphical path from a random starting location to a square table in an exemplary embodiment of the invention;

FIG. 3b is an exemplary diagram of a robot from a random starting position to a graphical path corresponding to a round table, and then to a graphical path corresponding to a square table in accordance with an exemplary embodiment of the present invention;

FIG. 3c is an exemplary diagram of a robot from a random starting position to a round table corresponding graphical path, and then to a square table corresponding graphical path in accordance with yet another exemplary embodiment of the present invention;

FIG. 3d is an exemplary diagram of a robot from a random one of the starting positions to a graphical path corresponding to a round table, and then to a graphical path corresponding to a square table in accordance with yet another exemplary embodiment of the present invention;

fig. 4 is an exemplary diagram of various graphical paths within multiple dining areas in an exemplary embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of 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. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In this document, suffixes such as "module", "component", or "unit" used to represent elements are used only for facilitating the description of the present invention, and have no particular meaning in themselves. Thus, "module," "component," or "unit" may be used in combination.

The terms "upper," "lower," "inner," "outer," "front," "rear," "one end," "the other end," and the like herein refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "mounted," "configured to," "connected," and the like, herein, are to be construed broadly as, for example, "connected," whether fixedly, detachably, or integrally connected, unless otherwise specifically defined and limited; the two components can be mechanically connected, can be directly connected or can be indirectly connected through an intermediate medium, and can be communicated with each other. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Herein, "and/or" includes any and all combinations of one or more of the associated listed items.

Herein, "plurality" means two or more, i.e., it includes two, three, four, five, etc.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Basic drawing: the "basic drawing" herein refers to a drawing sent from upstream, including a plan layout drawing, in which a drawing is required to be drawn by the drawing robot. For example, a restaurant plane layout drawing to be decorated is sent upstream, wherein each dining table, dining chair, surrounding decorative articles thereof and the like are a loft drawing frame (also called a graphic path drawn by the loft robot) required to be drawn on the restaurant floor by the drawing robot according to the plane layout drawing.

"starting point": the "starting point" herein refers to the first point of the drawing robot from the starting position or the previous graphic path to the current graphic path, and the point may be the end points at two ends of a line segment in the graphic path, or any point between the two end points, which only needs to meet the shortest connection line or distance between the two end points and the current position of the drawing robot (the connection line or distance herein refers to the straight line distance between the two points).

The invention is mainly suitable for scenes of large-area restaurants, dining halls, large-area offices and the like which need to draw a large number of lofting frames on the ground, and particularly relates to the drawing of lofting frames of tables, chairs and the like on the ground in the early period of decoration, for example, lofting frames of tables, chairs and the like on the ground are drawn by using a lofting robot.

The scene characteristics of large tracts of land dining room, office, library lie in: the dining table has larger dining chair (or table chair) quantity, smaller gap between tables and dense arrangement; to accommodate a different number of diners, it is necessary to prepare different desks, for example, a square table capable of accommodating 2 persons, a square table capable of accommodating 3-4 persons; square or round tables capable of accommodating 6-8 people; round tables capable of accommodating 8-10 persons or more, and, in order to leave a space for activity, the distance between dining tables capable of accommodating more persons is relatively large; for dining chairs, the drawing of the loft frame is usually performed when the loft frame is returned to the dining position corresponding to the dining table or is performed when no person uses the loft frame of the dining chair, and at this time, the loft frames of the dining chair are usually connected together as a whole, see fig. 3a and 3b.

For the above scene characteristics, considering that the arrangement mode between dining tables has a certain rule, in general, only the lofting frames need to be drawn one by one according to the arrangement rule of dining tables, for example, the lofting frames need to be drawn one by one in a column or one by one. However, from the perspective of the user, the table and the dining chair are taken as a whole, and the loft frames of the dining tables are actually repeatedly drawn with the same pattern.

However, for a payoff robot, instead of drawing a table and its suite of chairs one line segment by one line segment, the line segments drawn each time may be different (e.g., different lengths, and/or directions, etc.), and the starting position of the line segments entering the venue to begin drawing is random, and the position of a loft graphic when drawn is random, i.e., the starting and final positions are indeterminate for a loft frame, so that the path traveled by the robot each time a loft frame is drawn is random, even though the same loft frame is drawn. On the other hand, not all dining table lofting frames in the dining area are identical and regularly arranged, and multiple desktops may exist in the same dining area at the same time, or the structure of the site is limited, so that part of dining tables cannot be regularly arranged. Therefore, if the conventional drawing method is used to increase the number of unnecessary paths repeatedly taken when the line drawing robot draws lines, the power consumption of the line drawing robot is increased, the line drawing time is prolonged, and the line drawing efficiency is reduced. Based on the above, the invention provides a method capable of reducing the repetition of unnecessary paths in the process of drawing lines from a random initial position to a certain extent, thereby improving the line drawing efficiency.

The invention provides a path finding method of a paying-off robot, which comprises paying-off path planning and paying-off path following.

The flow of the step of planning the paying-off path in S1 is shown in FIG. 1, and comprises the following steps:

s11, dividing the ground of the to-be-paid-out site in the basic drawing into a plurality of dining areas in advance.

Generally, when a large area of a field is provided and more tables and chairs are arranged on the bottom surface of the field, the field is divided into subareas. For example, large restaurants and canteens are arranged in order to accommodate more diners, tables and chairs are arranged in order and dense, and areas are possibly divided according to supplied multi-style foods and even dining environments, for example, cafeterias of some large hotels are divided into fresh food supply areas, chinese meal areas and western meal areas, and corresponding dining positions are arranged nearby; as another example, some restaurants have lobbies, bundles, VIP rooms, and the like. Therefore, in the invention, the restaurant is divided into a plurality of dining areas according to the inherent scale and layout of the restaurant. Of course, other rules may be installed to divide the sub-regions. The following will take a large restaurant as an example.

S12, aiming at each dining area, using a dining table as a unit, and connecting the dining table and the dining chairs around the dining table by using straight line segments and/or arcs to form independent lofting patterns; all straight line segments or arcs in the loft pattern are directly or indirectly connected.

Dining tables in restaurants and canteens are generally rectangular or circular in shape, and for rectangular dining tables, straight line segments are adopted when drawing loft figures, see fig. 3a. For a round table, an arc line and a straight line are combined when drawing a lofting graph, see fig. 3b. The lofting patterns obtained by connecting each dining table and the dining chairs around the dining table are all independent patterns, but all lines in each lofting pattern are directly or indirectly connected, so that island is avoided.

S13, reading point coordinates of line segments to be drawn in each lofting graph.

Generally, the robot obtains the coordinates of each dining table and dining chair in the drawing from the layout drawing of the dining chair and the like fed back from the upstream, and the coordinates of each point can be obtained according to the drawing and the site drawing proportion.

S14, searching the nearest point which is the shortest in distance from the initial position of the paying-off robot in all the lofting graphs, and taking the lofting graph where the nearest point is located as the path starting point of the paying-off robot in the lofting graph.

In some embodiments, the closest point may be any point between two endpoints of a line segment in the loft graphic, or may be the endpoint itself. Referring to fig. 3a and 3c, the closest point is a point on a line segment in the loft graphic; referring to fig. 3b and 3d, the closest point is the end point of the line segment in the loft pattern.

The purpose of the paying-off robot for finding the nearest point with the shortest linear distance from the current position in the lofting graph is as follows: because the initial position of the paying-off robot is random, and a plurality of lofting graphs needing to be drawn can exist nearby the initial position at the same time, and the lofting graphs can belong to the same dining area or different dining areas, so that in order to find the optimal path required by the drawing of the robot, the drawing can be efficiently performed, and the robot needs to enter the lofting graphs as soon as possible.

In this step, the method for finding the nearest point includes:

s141, acquiring point coordinates of the starting position of the paying-off robot.

S142 traverses the coordinates of all points in all loft drawings of the line to be drawn.

In some embodiments, the all points include points on a straight line segment or arc connecting the respective endpoints, as well as the endpoints themselves; of course, in other embodiments, only the coordinates of all points in the loft patterns closest to the start position (e.g., less than a preset threshold distance from the start position) may be traversed.

S143, obtaining the distance from the initial position of the paying-off robot to all points in each lofting graph by using the coordinates of the initial position point and the coordinates of all points in the lofting graph.

S144, selecting the point with the shortest distance from the initial position point, namely the nearest point, as a path initial point for the robot to traverse all points in the lofting graph so as to traverse all line segments in the lofting graph.

S15, after traversing all line segments in the lofting graph, searching a next nearest point with the shortest distance from the current position of the lofting robot, wherein the nearest point belongs to the lofting graph of the next line to be drawn in the current dining area, and taking the nearest point as a path starting point of the lofting graph traversed by the lofting robot through all line segments in the next lofting graph; and repeating the steps until the line segments in the lofting graphs of all the lines to be drawn in the current dining area are traversed, searching for the next nearest point which is shortest in distance from the current position of the paying-off robot, wherein the next nearest point belongs to other dining areas, traversing the line segments of all the lofting graphs in the other dining areas in the same way, repeating the steps until the line segments of all the lofting graphs in all the dining areas are traversed, and finally obtaining a planned path.

In the invention, the line drawing principle of the paying-off robot is as follows: and aiming at the same dining area, after the line drawing of each line segment in one lofting graph is finished, driving to the next lofting graph, and drawing each line segment in the next path graph until the line segments in all the lofting graphs are finished. After the robot finishes drawing the last line segment in one lofting graph, the robot stays in place, then traverses all points in all other lofting graphs which are not drawn, and searches for the closest point with the shortest distance from the current position. The searching method is the same as the method for searching the closest point in step S14, and will not be described in detail in this step.

For example, referring to FIG. 3B, when the loft pattern for the round table, when sequentially passing through the points B21-C21-D21-A21-B21-E21 from the start point A21 until the corresponding loft pattern is drawn, the current position of the robot is point C21, then a point C11 closest to the point C21 in the next graph path is searched, and the point C11 is used as the starting point of the robot in the graph path to draw a line segment.

For another example, referring to FIG. 3C, when starting from the starting point N21, the points A21-B21-C21-D21-N21-C21-F21. E21-B21 are sequentially traversed, i.e. the corresponding graphic path is drawn, the current position of the robot is a point B21, then a point M11 closest to the point B21 in the next lofting graph is searched, and the point M11 is used as a starting point of the robot in the lofting graph.

For different dining areas, after the last line segment in one dining area is drawn, the method stays in place, then all points in all other lofting graphs which are not drawn in other dining areas are traversed, the nearest point with the shortest distance to the current position of the nearest point is searched, then all line segments are drawn according to the path planning mode in the same dining area, and after all line segments in the dining area are drawn, line segments of all lofting graphs of the next dining area are drawn in the same mode.

In this embodiment, the line is drawn by taking the dining area as a unit, and when the line is drawn, the shortest distance between points is used as a standard to select the optimal path, so that the probability of frequent repeated path walking of the robot is reduced or avoided as much as possible, and the line drawing efficiency is further provided.

In addition, as shown in fig. 2, the path planning step of the robot in the lofting graph in the present invention includes the following steps:

and S151, the robot starts from a path starting point in the lofting graph, runs to an end point with the shortest path between the path starting point and the path starting point, draws a line, runs along the next line segment with the shortest path connected with the end point and draws the line after drawing the line, and finishes drawing the line until all the line segments in the lofting graph are traversed.

The starting point of the path in the loft pattern may or may not be the end point of the line segment, and is determined according to the current position of the robot outside the loft pattern. The robot is looking for a point closest to the current position.

In some embodiments, when the payoff robot reaches an end point/path start point and completes drawing a line, the payoff robot travels along the next end point of the shortest path (i.e., the shortest length line segment) connected to that point and draws a line, and so on, until all line segments in the graph are traversed.

In some embodiments, during the traversal, the paying-off robot records an intersection every time it passes through an intersection, and returns to the last intersection when the paying-off robot travels to the end of the path. Specifically, when the paying-off robot runs to one end, whether the end point which runs currently is connected with an unpainted line segment or not is judged, and if the end point which runs currently is not connected with the unpainted line segment, the end point of the path which runs currently is indicated.

The intersection is a point where 3 or more paths are connected. The purpose of recording intersections is to prepare for encountering the end of a path (dead end). The end of the path (dead end) refers to all drawn lines of the line segment connected with the current point of the robot. For example, referring to fig. 3a, the robot passes the end points in sequence from the path start point a 11: B11-C11-D11-F11 (intersection) -C11 (intersection), a dead-end is encountered (because the line segment connected to the point C11 is all drawn, and at the same time, the point C11 is also an intersection having three paths), so it is necessary to return to the last intersection that has been travelled, i.e., the point F11, and then travel to the point G11 along the line segment F11G11 that is not drawn and draw the line segment F11G11.

In some embodiments, the line segments and their endpoints for the drawn line are marked in the graph, avoiding repeated drawing and affecting the planning of the travel route. After the robot finishes drawing the line at the end of the path, the robot returns to the last intersection, marks the drawn line path, and prevents the robot from walking to the end of the path again.

Because of the large area of dining halls, dining tables are relatively dense, so that the distance between the dining tables and the current position path of the robot is more than one point which is short, and a plurality of points need to be selected. In the invention, the selected rule is to select the endpoint preferentially, if there is no endpoint, the point on the line segment is selected.

Further, if the plurality of closest points include a plurality of endpoints, one endpoint that is marked first/read first is selected as the closest point according to the marking order/reading order of each endpoint in the original design drawing. For example, referring to fig. 3D, the initial position of the robot is located at the center of the circular table, and all points on the circle are the nearest points, so first, the intersection point (i.e. the end point of the line segment) of the dining chair and the corresponding loft frame of the table is selected, for example, D22, a22, f22··; then, one endpoint A22 read first is selected as a path starting point of the robot to start drawing lines, sequentially passes through B22-C22-D22-A22-F22-D22, finally, a point closest to the point D22 in the next lofting graph is searched at the point D22 as the path starting point, M12 is found, and sequentially passes through the points A12-D12-C12-B12-M12-C12 (namely, the last intersection connected with an unpainted line segment C12E 12) to return to E12-D12, so that graph drawing is completed.

In other embodiments, if the robot rolls back to the previous intersection and is not connected with the line segment, the robot rolls back to the next intersection and judges whether the robot is connected with the line segment, and the operation is repeated until an intersection connected with the line segment is found in the path which has been driven. Of course, if no intersection is found where an unpainted line segment is connected, the robot directly moves back to the starting point within the graphical path.

Therefore, in this embodiment, when the robot runs in the graphic path to draw lines, the starting point and all the intersections passing through are recorded, and once the robot encounters a dead road, the robot finds the nearest intersection connected with the line segment which is not drawn from among all the intersections passed through the running path, and then starts to run to draw lines; if all the crossing points are not connected with the line segments which are not drawn, the method returns to the starting point. This ensures that all segments can be drawn when the starting point is not on the end point.

In addition, in order to make the distance travelled by the robot shorter, when the robot is retracted to the intersection or the starting point connected with the line segment which is not drawn, a connecting line (or a straight line path, but the connecting line does not need to draw a corresponding line segment) between the two points is taken as a retraction path, and the robot does not need to return according to the original path. For example, referring to fig. 3C, when the robot sequentially passes through points a21-B21-C21-D21 from the start point N21 and returns to the point N21, since all line segments connected to the point N21 have been drawn, the last intersection, i.e., the point C21, is returned, and the line between the points N21 and C21 is directly regarded as the travel path of the robot instead of the original path. As is also path M12C12 in fig. 3 d.

It is also possible that when the robot starts or travels to an intersection in the graphical path, there are a plurality of end points corresponding to the start or intersection, and a plurality of end points are all the same shortest connecting distance, and the end points need to be selected. In the invention, the rule is to select the endpoint read first according to the reading sequence of the graph path and then drive the drawing line.

However, due to the special nature of the connection of the table and the dining chair, for example, the length of each line segment of the lofting frame of the chair is smaller than the distance between the dining chairs, the robot may directly retract to the starting point during the line drawing process, for example, from the starting point a21, sequentially: points B21-C21-D21 and back to the starting point a21. At this time, still according to the above method, it is sufficient to find the point B21 closest to the point a21 and to which the line segment not drawn (i.e., the line segment B21E 21) is connected, and then to drive the line from the point B21 to the point E21, see fig. 3B.

After the path is planned, the line is drawn along with the planned path. In the existing path following method, most of the path following methods are applied to vehicle following, and as the vehicle following method mainly ensures that the vehicle driving direction and the deviation between the path and the driving path are not large, namely the following accuracy requirement is not high, for example, drift can occur due to inertia when turning or curve driving. For robots for other applications, the above-mentioned deviation may be less susceptible. However, the paying-off robot using the scene of the invention is a restaurant with a large area, and the lofting patterns are relatively dense, namely, the lofting patterns need to be drawn with a large density, so that the requirements on the following precision are high, and therefore, the deviation between the actual running path and the planned running path when the robot draws the lines needs to be reduced as much as possible.

The path following method is also optimized in the present invention.

S2, a path following method based on the planned path obtained by the path planning method is shown in FIG. 2, and comprises the following steps:

s21 identifies the type of the current road segment or the next road segment to be traveled by the paying-off robot, if the road segment is a straight road segment, step S22 is performed, and if the road segment is a curved road segment, step S23 is performed.

As the dining tables in the dining room are provided with square tables and round tables, straight line sections are adopted as lofting frames for the square tables and dining chairs, and the dining chairs and the lofting frames of the dining tables are connected together to form a whole, so that corresponding planning paths are obtained; for round tables and dining chairs thereof, the arc lines are adopted to draw the dining tables, and the dining chairs are connected with the lofting frames of the dining tables by adopting straight line segments to form a whole, so that corresponding planning paths are obtained. The robot also selects different travel modes for different types of paths.

In some embodiments, the path between two points that are generally closer together is a segment, for example, between two adjacent end points, or between an end point and the starting point of the path is a segment, as described above, because the distance of each segment is not too long because of the special scene of the restaurant, there may generally be one segment or more than one segment within a forward looking distance of the line drawing robot.

S22, setting a following point on a planned path for the paying-off robot based on the initial forward looking distance.

Initializing a preset initial forward looking distance, projecting a point on the planned path according to the length of the forward looking distance, and taking the point as a following point. The following point acts as the "antenna" of the robot for detecting the path in front and for the robot to follow.

S24, the paying-off robot runs to the following point, and the following point is propelled during running, so that the initial forward looking distance is kept between the following point and the robot.

When the robot runs, the following point also advances forward. The distance maintained between the two is the initial forward looking distance.

And S25, in the running process, judging whether an inflection point appears in the forward looking distance, if so, executing a step S26, otherwise, continuing running.

S26 sets the inflection point or end point as the following point and stops advancing the following point.

In some embodiments, the inflection point is a corner or an intersection where a turn is desired, such as a corner between a straight road segment and a curved road segment. Because the invention has higher requirements on the stability and the accuracy of the robot, the following point is stopped at the inflection point to advance when the situation that the robot needs to turn is met.

S27, the paying-off robot runs to the inflection point/end point, and when the paying-off robot runs to the inflection point, the paying-off robot rotates in situ by a corresponding angle according to the path included angle of the inflection point/end point, and then sets a following point on a planned path for the paying-off robot according to the initial forward looking distance, and runs and advances the following point according to the following point.

In order to avoid drifting, the wire-releasing robot turns in the invention in a way of reaching the turning position first and then turning under the static condition, so that the drifting phenomenon can be avoided to the greatest extent.

The curved path pattern includes:

s23, judging whether the curvature of the current road section changes, if so, executing step S30, otherwise, executing step S29.

S29, setting the steering angle of the paying-off robot and adjusting the initial forward looking distance based on the curvature of the current road section, setting the following point on the planned path based on the adjusted initial forward looking distance, then driving to the following point, and maintaining the forward looking distance with the following point in the driving process.

Specifically, the method for setting the steering angle of the robot based on the curvature of the current road section comprises the following steps:

using the formula

Calculating the steering angle of the paying-off robot, wherein delta is the steering angle of the robot, L is the wheelbase of the robot, and L _d For forward looking distance, α is the angle of orientation of the following point.

When the arc path is passed, a proper forward looking distance needs to be set. Too large or too small a forward looking distance can cause oscillations that cause the robot to sway.

In the present invention, the curvature of the path does not change too much (the specification of the round table is not too much), and the curvature of the path does not change continuously in a short distance, such as a spiral path. Of course, not all dining chairs are represented by boxes, and for some scenarios, a round bar chair, or a dining chair formed by two curved bars of different curvatures joined together, may be used. Even for some independent style design scenarios, it is also possible to use a dining table that is not a conventional round table, but a table that is surrounded by two or three curved bars of different curvatures. Therefore, the corresponding relation between the curvature of the corresponding road section in the planned path and the forward looking distance is a preset value. That is, after the curvature of the corresponding road section in the planned path in the forward looking distance is calculated, the robot finds the preset forward looking distance to adjust. The savings in doing so increase response time.

Of course, for some cases where the scene is complex, such as where a continuously varying curvature occurs, the transformation may be performed using PID control or a formula that sets a curvature to a forward viewing distance.

S30 sets the curvature change start point as the following point, and stops advancing the following point.

For example, when encountering the junction of two arcs with different radians and opposite bending directions, the robot will stay at the following point.

S31, the paying-off robot runs towards a curvature change starting point, when the curvature change starting point is reached, the steering angle and the forward looking distance of the paying-off robot are adjusted based on the new curvature, a new following point is set on a planning path based on the adjusted forward looking distance, and the paying-off robot continues to run according to the planning path, and step S25 is executed. The new curvature refers to the curvature of the road segment after the curvature change starting point in the current road segment, or the curvature of the next road segment.

In other embodiments, the running speed of the paying-off robot can be properly adjusted according to the distance between different dining areas, the density of the patterns in the same dining area and the distance between different patterns, so that smooth line drawing is ensured, and meanwhile, the energy consumption of the robot is reduced to a certain extent, and the efficiency is improved. Specifically, the method further comprises the steps of:

when the robot runs in the current dining area, the density rho of the graph in the current dining area is obtained in advance, whether the density rho is larger than a preset density threshold value or not is judged, and if yes, the speed increment is K ₃ ﹡ DeltaV; otherwise, the speed increment is K ₄ ﹡ΔV；

Further, whether the average distance between the patterns in the current dining area is smaller than or equal to a first preset distance threshold value is judged, and if yes, the current running speed is reduced according to a preset first speed increment V1.

Correspondingly, when the robot finishes drawing lines in the current graph, judging whether the distance between the next graph to be drawn and the current graph is larger than a second preset interval threshold value, if so, reducing the current running speed according to a preset third speed increment V3; otherwise, the current driving speed is increased according to a preset fourth speed increment V4, wherein V ₃ ＝K ₅ ﹡ΔV，V ₄ ＝K ₆ ﹡ DeltaV, and K ₅ ＜K ₆ DeltaV is a preset delta speed.

The coefficients K1 to K6 may be set in advance according to the area of each dining area and the distance between each other. By adjusting the running speeds among different dining areas and adjusting the running speeds among different figures in the dining areas, the line drawing efficiency is improved as much as possible while smooth line drawing is ensured, and the energy consumption of the robot is saved.

In addition, the invention also provides a paying-off robot, and when the paying-off robot is applied to large-area restaurant decoration, the paying-off and road-finding method is adopted to draw each lofting graph.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are to be protected by the present invention.

Claims

1. The path finding method of the paying-off robot comprises paying-off path planning and path following based on the planned path obtained by planning, and is characterized in that,

The paying-off path planning step comprises the following steps:

reading the lofting graph needing to be drawn in the basic drawing;

2. The line-laying robot path-finding method according to claim 1, wherein the line-laying robot path-planning step in the loft pattern includes:

the paying-off robot starts from the path starting point in the lofting graph, runs to the end point with the shortest path between the path starting point and the path starting point, draws a line, runs along the next end point with the shortest path connected with the end point after drawing the line, and draws the line until all line segments to be drawn in the lofting graph are drawn; and, in addition, the processing unit,

in the running process, the paying-off robot records each crossing passing by, wherein the crossing is an end point connected with three or more line segments; and when the paying-off robot runs to the end of the path, the paying-off robot rolls back to the last intersection.

3. The line-laying robot path-finding method according to claim 2, wherein when a nearest point to a path of a current position of the line-laying robot within the lofting pattern includes any one point on at least one line segment and a plurality of end points, the line-laying robot selects the end point, which is read first, as a path start point in the lofting pattern in a reading order of the plurality of end points.

4. The line-laying robot path-finding method according to claim 2, wherein the step of finding a closest point having a shortest distance from the start position of the line-laying robot comprises:

acquiring point coordinates of the initial position of the paying-off robot;

5. The pay-off robot routing method of claim 1, wherein the method of setting the robot steering angle by planning the path curvature is:

Using the formula

6. The payoff robot routing method as claimed in claim 1, wherein a correspondence between a curvature of the next road section and the forward looking distance is a preset value.

7. The pay-off robot routing method of claim 2, further comprising the steps of: when the paying-off robot draws lines in a current dining area, judging whether the average distance between lofting graphs in the current dining area is smaller than or equal to a first preset distance threshold value, if so, reducing the current running speed according to a preset first speed increment V1; otherwise, the current running speed is increased according to the preset second speed increment V1,

wherein V is ₁ ＝K ₁ ﹡ΔV，V ₂ ＝K ₂ ﹡ DeltaV, and K ₁ ＜K ₂ DeltaV is the incremental speed.

8. The pay-off robot routing method of claim 7, further comprising the steps of: when the paying-off robot runs in a current dining area, acquiring the density rho of the lofting graph in the current dining area in advance, judging whether the density rho is larger than a preset density threshold value, and if so, judging that the speed increment is K ₃ ﹡ DeltaV; otherwise, the speed increment is K ₄ ﹡ DeltaV; wherein K is ₃ ＜K ₄ 。

9. The pay-off robot routing method of claim 8, further comprising the steps of: when the paying-off robot finishes drawing a current lofting graph, judging whether the distance between the next lofting graph to be drawn and the current lofting graph is larger than a second preset interval threshold value, if so, reducing the current running speed according to a preset third speed increment V3; otherwise, the current running speed is increased according to a preset fourth speed increment V4,

wherein V is ₃ ＝K ₅ ﹡ΔV，V ₄ ＝K ₆ ﹡ DeltaV, and K ₅ ＜K ₆ DeltaV is the incremental speed.

10. A paying-off robot, wherein the paying-off robot uses the road-finding method according to any one of claims 1 to 9 to draw a line when finishing.