Path planning method, device and snow sweeper

Abstract

The present invention relates to the technical field of automatic snow sweepers, and particularly to a path planning method, device and snow sweeper. The method includes: obtaining the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map; determining the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position; planning a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction; and controlling the automatic snow sweeper to automatically travel based on the snow sweeping path, so that the automatic snow sweeper optimally plans the snow sweeping path and improves the snow sweeping efficiency of the automatic snow sweeper.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic snow sweepers, and particularly to a path planning method, device and snow sweeper. Background Art

[0002] In the past technical background, the operation mode of most snow sweepers relied on manual control to guide the movement direction of the machine, so as to determine the snow cleaning path. This traditional method has some obvious limitations.

[0003] Since the snow sweeper relies on manual operation, it is impossible to achieve intelligent path planning. Manual operation is easily affected by the operator's personal experience and skills, resulting in a lack of systematicness and scientificity in the selection of the snow cleaning path. Under complex weather and terrain conditions, it is difficult for the operator to comprehensively consider various factors, so that the snow cleaning path cannot be optimized, resulting in low efficiency and resource waste.

[0004] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of the present invention is to provide a path planning method, device and snow sweeper, aiming to solve the technical problem that the snow sweeper in the prior art relies on manual operation and cannot achieve intelligent path planning.

[0006] To achieve the above purpose, the present invention provides a path planning method, and the path planning method includes the following steps:

[0007] Obtain the snow throwing position and the current position of the automatic snow sweeper in the snow cleaning map;

[0008] Determine the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position;

[0009] Plan a snow cleaning path that conforms to a preset rule in the snow cleaning map based on the snow throwing direction;

[0010] Control the automatic snow sweeper to walk automatically based on the snow cleaning path.

[0011] Optionally, before obtaining the snow throwing position and the current position of the automatic snow sweeper in the snow cleaning map, it further includes:

[0012] Obtain the longitude and latitude coordinates of the target snow throwing area and the target snow cleaning area through the fusion positioning technology of multiple sensors, and convert the longitude and latitude coordinates into a snow cleaning map coordinate system based on the origin;

[0013] Perform rasterization and potential field transformation on the target snow throwing area and the target snow cleaning area based on the snow cleaning map coordinate system to generate a snow cleaning map.

[0014] Optionally, planning a snow clearing path that conforms to a preset rule in the snow clearing map based on the snow throwing direction includes:

[0015] Determine whether there are multiple snow clearing areas in the snow clearing map;

[0016] If there are multiple snow clearing areas, determine whether the multiple snow clearing areas form a connected domain;

[0017] If a connected domain is formed, determine the connection route of the area passed between two adjacent snow clearing areas;

[0018] Based on the snow throwing direction and the connection route, plan a snow clearing path that conforms to a preset rule in the snow clearing map.

[0019] Optionally, after controlling the automatic snow sweeper to automatically travel based on the snow clearing path, it further includes:

[0020] When receiving the modification information of the snow throwing position, obtain a new snow throwing direction based on the modification information of the snow throwing position and the current position;

[0021] Re-adjust the snow clearing path according to the new snow throwing direction to obtain a target planned path;

[0022] Control the automatic snow sweeper to automatically travel based on the target planned path.

[0023] Optionally, after controlling the automatic snow sweeper to automatically travel based on the snow clearing path, it further includes:

[0024] Determine the position deviation information of the automatic snow sweeper according to the fusion positioning information of the automatic snow sweeper;

[0025] Based on the position deviation information of the automatic snow sweeper, adjust the position of the fuselage to the position on the snow clearing path by means of PID control.

[0026] Optionally, adjusting the position of the fuselage to the position on the snow clearing path by means of PID control based on the position deviation information of the automatic snow sweeper includes:

[0027] Determine the deviation angle of the automatic snow sweeper according to the current point of the automatic snow sweeper and the target point on the snow clearing path;

[0028] Determine the linear velocity and angular velocity of the automatic snow sweeper based on the deviation angle of the automatic snow sweeper;

[0029] Adjust the position of the fuselage on the snow clearing path based on the linear velocity and angular velocity of the automatic snow sweeper.

[0030] Optionally, after controlling the automatic snow sweeper to automatically travel based on the snow sweeping path, the method further includes:

[0031] During the automatic travel of the automatic snow sweeper, adjust the spacing in the snow sweeping path according to the thickness of the snow, and re-plan the snow sweeping path based on the adjusted spacing.

[0032] Optionally, after controlling the automatic snow sweeper to automatically travel based on the snow sweeping path, the method further includes:

[0033] During the automatic travel of the automatic snow sweeper, after determining that there is an obstacle affecting the movement on the snow sweeping path, control the automatic snow sweeper to bypass the obstacle and return to the snow sweeping path to continue traveling.

[0034] In addition, to achieve the above object, the present invention further provides a path planning device, which includes:

[0035] A position acquisition module, configured to acquire the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map;

[0036] A direction acquisition module, configured to determine the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position;

[0037] A path acquisition module, configured to plan a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction;

[0038] A travel execution module, configured to control the automatic snow sweeper to automatically travel based on the snow sweeping path.

[0039] In addition, to achieve the above object, the present invention further provides a snow sweeper, which includes a traveling device, a snow removing device, a vehicle body device, and a control device. The control device includes a memory, a processor, and a path planning program stored on the memory and executable on the processor. The path planning program is configured to implement the steps of the path planning method according to any one of claims 1 to 8.

[0040] The present invention acquires the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map; determines the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position; plans a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction; and controls the automatic snow sweeper to automatically travel based on the snow sweeping path, so as to optimize the snow sweeping path planning of the automatic snow sweeper and improve the snow sweeping efficiency of the automatic snow sweeper. Description of the Drawings

[0041] Figure 1 It is a schematic structural diagram of the snow sweeper involved in the embodiment solution of the present invention;

[0042] Figure 2 It is a schematic structural diagram of a control device for a hardware operating environment involved in the solution of an embodiment of the present invention;

[0043] Figure 3 It is a schematic flowchart of the first embodiment of the path planning method of the present invention;

[0044] Figure 4 It is a schematic flowchart of the second embodiment of the path planning method of the present invention;

[0045] Figure 5 It is a schematic diagram of rasterization and potential field generation in the second embodiment of the path planning method of the present invention;

[0046] Figure 6 It is a schematic flowchart of the third embodiment of the path planning method of the present invention;

[0047] Figure 7 It is a structural block diagram of the first embodiment of the path planning device of the present invention.

[0048] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0049] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0050] Refer to Figure 1 , Figure 1 It is a schematic structural diagram of a snow sweeper involved in the solution of an embodiment of the present invention.

[0051] Refer to Figure 2 , Figure 2 It is a schematic structural diagram of a control device for a hardware operating environment involved in the solution of an embodiment of the present invention.

[0052] Such as Figure 2As shown in the figure, the control device may include: a processor 1001, such as a Central Processing Unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display). Optionally, the user interface 1003 may further include a standard wired interface and a wireless interface. For the wired interface of the user interface 1003, it may be a USB interface in the present invention. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a Wireless-Fidelity (WI-FI) interface). The memory 1005 may be a high-speed Random Access Memory (RAM) or a stable memory (Non-volatile Memory, NVM), such as a disk memory. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0053] Those skilled in the art can understand that Figure 2 the structure shown in does not constitute a limitation on the control device, and it may include more or fewer components than shown in the figure, or combine some components, or have different component arrangements.

[0054] As Figure 2 shown, the memory 1005, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and a path planning program.

[0055] In Figure 2 the control device shown, the network interface 1004 is mainly used to connect to the background server and communicate with the background server for data; the user interface 1003 is mainly used to connect to peripheral devices; the path planning device calls the path planning program stored in the memory 1005 through the processor 1001 and executes the path planning method provided by the embodiments of the present invention.

[0056] Based on the above hardware structure, an embodiment of the path planning method of the present invention is proposed.

[0057] Referring to Figure 3 , Figure 3 is a schematic flowchart of the first embodiment of the path planning method of the present invention, and the first embodiment of the path planning method of the present invention is proposed.

[0058] In the first embodiment, the path planning method includes the following steps:

[0059] Step S10: Obtain the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map.

[0060] It should be noted that the execution entity of this embodiment can be a control device with data processing, network communication, and program running functions. The control device is used to control a snow sweeper, and the snow sweeper further includes a traveling device, a snow removal device, and a vehicle body device.

[0061] It can be understood that the snow throwing position refers to the specific position on the map where the automatic snow sweeper throws the snow after completing the snow clearing operation. This position can be set in advance or determined dynamically according to the needs of the snow clearing task. The selection of the snow throwing position may consider factors such as the surrounding environment, buildings, roads, etc., to ensure that the snow throwing does not have an adverse impact on the surroundings.

[0062] It should be understood that the current position refers to the geographical location where the automatic snow sweeper is located in real time during the snow clearing task. Through the sensors carried, the snow sweeper can accurately obtain its own coordinates on the map, so as to maintain an accurate perception of its own position throughout the working process.

[0063] In a specific implementation, the automatic snow sweeper can obtain information on the snow throwing position and its own current position in the snow clearing map by carrying various sensors, such as GPS, lidar, cameras, etc. These sensors can accurately capture the position of the machine on the map and the information of the surrounding environment.

[0064] It can be understood that the automatic snow sweeper can determine the snow throwing position according to the edge position in the snow clearing map; among them, according to the environmental information, it is determined that some of the outermost edge positions in the snow clearing map are non-working areas, and at this time, they can be regarded as snow throwing positions. For example, the outermost edge position in the snow clearing map that is far from the house in the environmental information is used as the snow throwing position.

[0065] It should be noted that the IMU sensor in the automatic snow sweeper can collect the slope of the ground information and determine the snow throwing position based on the slope situation; among them, when the snow is not deep, the ground with a steeper slope may cause the snow to roll. At this time, the determined snow throwing position can be a flat ground. The method for the IMU sensor to determine the snow throwing position on the flat ground can also be determined using a vision sensor. Among them, it is recognized by the vision sensor that the ground is on the same straight line.

[0066] Step S20: Determine the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position.

[0067] It should be noted that the snow throwing direction refers to the direction of the snow throwing tube. When rasterizing the snow sweeping map, according to the snow throwing direction, the snow throwing tube direction corresponding to each grid of the automatic snow sweeper can be obtained, and when sweeping the snow, the snow throwing tube of the automatic snow sweeper is controlled in the correct snow throwing tube direction. Among them, rasterizing the snow sweeping map means dividing the snow sweeping map into multiple grids, and setting a corresponding potential energy value for each grid through the Breadth-First Search (BFS) algorithm. Taking Figure 5 the right half part shown as an example, the potential energy value of the grid where the snow throwing position is located can be set to 0, and each time it spreads one layer outward from the snow throwing position, the potential energy value of the corresponding layer of grids is increased by 1, and finally, an image of the potential energy value distribution as shown in Figure 5 the right half part is formed.

[0068] Step S30: Plan a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction.

[0069] It should be noted that the snow sweeping path of the preset rule can include a path with high or low potential energy or a path formed after being blocked by obstacles (this path includes a path affected by the connected domain or a path formed after being blocked by static or dynamic obstacles); among them, the high or low potential energy refers to the distance of the automatic snow sweeper from the snow throwing position (the farther the distance, the greater the potential energy of snow throwing) and the direction (the more deviated the direction of the machine relative to the snow throwing position, the greater the potential energy of snow throwing); being affected by the connected domain means that in the working area, the machine is blocked by a large area of obstacles from performing normal bow-shaped sweeping, and thus multiple partitions are formed in the working area, and there may be at least one connected domain in each area. For example Figure 5 the right half part and Figure 5 the left half part are respectively areas of two partitions, and Figure 5 the area with a grid potential energy value of 5 in the right half part and Figure 5 the area with a grid potential energy value of 1 in the left half part, the junction between them is a connected domain. At this time, when the machine is walking, it first walks from high potential energy to low potential energy in the Figure 5 left half part area, and finally determines the shortest path to reach the Figure 5 right half part area based on the position of the connected domain, thereby avoiding the machine walking too many invalid paths.

[0070] Step S40: Control the automatic snow sweeper to walk automatically based on the snow sweeping path.

[0071] It should be noted that the snow-sweeping path of the automatic snow sweeper adopts a bow-shaped path. Walking along this path, after determining the snow-throwing position, the fuselage can move from high potential energy to low potential energy (specifically including: first sweeping the outer circle of the snow-throwing position and throwing the snow outside the snow-throwing circle into the snow-throwing position, then first cleaning the area where the snow cannot be thrown to the snow-piling position point and throwing the snow into the uncleaned area, and finally cleaning the area where the snow can be thrown to the snow-piling position), so that the snow falls into the snow-throwing position.

[0072] It should be understood that the snow-sweeping method of the automatic snow sweeper in this embodiment is to roll the snow by the snow-rolling blade, throw the snow by the snow-throwing blade, and finally throw it into the snow-throwing position set by the user through the snow-throwing tube. Therefore, the path planning needs to consider the snow-throwing direction of each position, and through the path planning, all the snow in the working area is piled up at the snow-throwing position.

[0073] It should be noted that after the obstacle blocks the snow from being thrown to the snow-throwing position, the snow can be first thrown to the uncleaned area where the snow can be correctly thrown to the snow-throwing position, and then the snow is thrown to the snow-throwing position through this area later. It is also possible to form multiple partitioned areas in the working area, and then throw the snow to the snow-throwing position through the communication area between each area.

[0074] It can be understood that after being partitioned, if the area of one of the areas is too small and insufficient for the machine to work or the obstacle blocks the snow from being thrown to the snow-throwing position, the snow removal work in this area can be not executed.

[0075] In the first embodiment, the snow-throwing position and the current position of the automatic snow sweeper in the snow-sweeping map are obtained; based on the snow-throwing position and the current position, the snow-throwing direction of the automatic snow sweeper is determined; based on the snow-throwing direction, a snow-sweeping path conforming to a preset rule is planned in the snow-sweeping map; based on the snow-sweeping path, the automatic snow sweeper is controlled to walk automatically, so that the automatic snow sweeper optimally plans the snow-sweeping path and improves the snow-sweeping efficiency of the automatic snow sweeper.

[0076] Refer to Figure 4 , Figure 4 This is the flow chart of the second embodiment of the path planning method of the present invention. Based on the first embodiment shown above Figure 3 a second embodiment of the path planning method of the present invention is proposed.

[0077] In the second embodiment, before the step S10, it further includes:

[0078] Step S01: Obtain the longitude and latitude coordinates of the target snow-throwing area and the target snow-sweeping area through the fusion positioning technology of multiple sensors, and convert the longitude and latitude coordinates into the snow-sweeping map coordinate system based on the origin.

[0079] It should be noted that the automatic snow sweeper includes a communication module, which can obtain the movement information sent by the mobile device. After the automatic snow sweeper moves to the designated location based on the movement information, a snow sweeping map of the automatic snow sweeper is formed through the RTK-odometry-IMU fusion positioning technology. Among them, the movement information refers to the information formed after manually operating the mobile device (handle) to control the movement of the automatic snow sweeper; the snow sweeping map is used for the subsequent automatic snow sweeper to plan a path after positioning.

[0080] In a specific implementation, the handle or the app-control machine (the handle is wireless communication control or the app-control machine is controlled by a cloud server) controls the automatic snow sweeper to move. The GPS-RTK base station gives the positioning information to the cloud server, and the current automatic snow sweeper gives the positioning information to the cloud server. The cloud server will combine the two to perform differential calculation to obtain the longitude, latitude and heading angle of the automatic snow sweeper, that is, the positioning of the automatic snow sweeper, and record the positioning to form a snow sweeping map. In addition, in this embodiment, it is also possible to adopt the method of preferentially walking non-cloud (local): the GPS-RTK base station gives the positioning information to the machine through lora wireless communication, and the machine combines its own positioning and the positioning of the base station to perform differential calculation to obtain the accurate positioning of the current machine (the positioning includes longitude, latitude and heading angle); in addition, a charging point can be set, and taking this charging point as the origin, a two-dimensional coordinate system covering the snow sweeping area is generated to make the generated snow sweeping map visual.

[0081] Step S02: Perform rasterization and potential field transformation on the target snow throwing area and the target snow sweeping area based on the snow sweeping map coordinate system to generate a snow sweeping map.

[0082] It should be noted that in the single - area snow - clearing strategy, the target snow - throwing area and the target snow - clearing area are rasterized and potential - field - processed, which specifically includes: 1. Rasterization: Find the minimum bounding rectangle of the cleaning area. Taking the lower - left corner as the origin and the length and width of the rectangle as the x - and y - axes to establish a coordinate system to rasterize the cleaning area. The unit 1 of the coordinate system is equivalent to 0.3m in reality. The center point of each grid is the target point for the machine to move. To ensure that automatic planning can also be enabled near the edge of the snow - clearing area, the number of grids is enlarged by a certain distance outside the minimum bounding rectangle; 2. Potential - field map: Among them, since the snow - clearing method is to rely on the machine to throw snow and finally pile it at the snow - throwing position, the potential energy of the snow - throwing position is marked as the lowest, and then the potential energy increases as the distance from the snow - throwing position increases. Based on this criterion, a potential - energy value is added to all grids. The route of the machine movement is from the position with high potential energy to the position with low potential energy. At the same time, the snow - throwing direction at each position is also towards the place with low potential energy, so as to ensure that the snow will finally be concentrated at the place with low potential energy, that is, the snow - throwing position; 3. After rasterizing the map, mark the categories of the grids (cleaned, uncleaned, restricted area, snow - throwing position), and bundle a series of connected snow - throwing grids together and mark them as a group. According to the upper, lower, left, and right boundaries of the group, find the most suitable direction for spreading potential energy (the longest side, aiming to walk in a straight line as long as possible to avoid turning). Starting from the lowest row, mark the grids in the same row with the same potential energy, and incrementally mark the potential energy row by row in the spreading direction (the reason for marking one row is to plan the route to walk in a straight line according to the same potential energy in the subsequent process) until it spreads to the boundary. The spread uses the breadth - first search algorithm. If the entire area has been spread in a single time, the potential - field processing is completed. Otherwise, take the grids at the spread boundary as the new snow - throwing positions and continue to repeat the above steps until the spread is completed. During the spread process, mark the snow - throwing direction of each grid, generally the grid with lower potential energy in the previous grid before spreading; 4. Route generation, including: Traverse the grids, find the grid with the maximum potential energy in the area, and start planning the route from this grid; Walk along the grids with the same potential energy until reaching the boundary, then find the adjacent grid with the next - lower potential energy, and check whether there is a grid with higher potential energy among the adjacent positions of this grid. If so, loop to find the grid point with the highest potential energy position, and plan the shortest snow - clearing route between the current cleaning position and the grid point with the adjacent highest potential energy position through the shortest - path algorithm. Repeat the above steps until the snow - clearing route reaches the end, and at the same time check whether there is still an uncleaned area in the area. If not, the route planning ends. Otherwise, continue to repeat the above steps until all routes are planned.

[0083] Further, in this embodiment, planning a snow clearing path that conforms to a preset rule in the snow clearing map based on the snow throwing direction includes: determining whether there are multiple snow clearing areas in the snow clearing map; if there are multiple snow clearing areas, determining whether the multiple snow clearing areas form a connected domain; if a connected domain is formed, determining a connection route of the area passed through between two adjacent snow clearing areas; and planning a snow clearing path that conforms to a preset rule in the snow clearing map based on the snow throwing direction and the connection route.

[0084] It should be understood that in the snow clearing strategy for multiple cleaning areas, the strategy for multiple areas currently uses the union-find set to determine whether the areas form a connected domain. The union-find set refers to a data structure for managing elements, usually used to handle set merging and searching operations. Each cleaning area is represented as a node, and the connection relationship between cleaning areas can be managed by the union-find set. When two areas are connected, they are regarded as a connected domain. If a connected domain is formed, the breadth-first search algorithm is used to find the connection route of the area passed through between two cleaning areas. The breadth-first search algorithm is a graph traversal algorithm. Its main feature is to traverse the nodes of the graph layer by layer starting from the starting node to find a specific target node, and it can calculate the shortest path from the starting node to the target node. In this embodiment, the shortest path between two cleaning areas is determined. Then, the cleaning strategy in a single area still uses the cleaning strategy of a single area; among them, the connection route can be a route determined by the user himself or a shortest path found by the machine based on the current position.

[0085] It should be noted that referring to Figure 5 , Figure 5 is a schematic diagram of rasterization and potential fieldization in the second embodiment of the path planning method of the present invention. Among them, each grid in the figure is a raster, the figure is divided into two areas, the junction of the numbers 1 and 5 is a connected domain, and the larger the number, the greater the potential energy. During the snow clearing planning process, the snow clearing robot will first walk in a bow shape to the raster far from the snow throwing position, throw the snow in the raster close to the snow throwing position, and finally walk to the raster close to the snow throwing position. For example, it first walks 3-2-1 in the area on the left of the snow throwing position, then enters the right area from the connected domain between 1 and 5, and enters the specified snow throwing position according to the path 5-4-3-2-1 to complete snow throwing.

[0086] In the second embodiment, the GPS-RTK positioning technology can provide high-precision position information, enabling the longitude and latitude coordinates of the target snow-throwing area and snow-clearing area to be accurately captured. This high-precision positioning can ensure that the generated snow-clearing map is highly consistent with the actual geographical environment, thus providing an accurate basis for subsequent path planning and navigation; rasterizing and potential-fieldizing the target area means converting continuous geographical information into discrete grids and then embedding potential-field information into them. Such optimization can better capture geographical features such as terrain, obstacles, and slopes, providing more accurate data for path planning; potential-fieldization can simulate the interaction between objects, such as avoiding obstacles, making the path planning more intelligent and flexible; the generated snow-clearing map can be presented in the form of a grid or potential field, enabling the operator to intuitively understand the geographical distribution of the target snow-throwing area and snow-clearing area, as well as possible obstacles and terrain features. Such visualization can help the operator better understand the working environment and provide support for subsequent planning and decision-making; based on the rasterized and potential-fieldized snow-clearing map, advanced path planning algorithms can be used to generate intelligent snow-clearing paths by combining factors such as terrain, obstacles, and optimization strategies. Such path planning can enable the automatic snow-clearing machine to perform snow-clearing tasks more efficiently and accurately, avoiding unnecessary round trips and resource waste.

[0087] Referring to Figure 6 , Figure 6 is a schematic flowchart of the third embodiment of the path planning method of the present invention. Based on the above Figure 3 shown in the first embodiment, the third embodiment of the path planning method of the present invention is proposed.

[0088] In the third embodiment, after the step S40, the following is further included:

[0089] Step S50: When receiving the modification information of the snow-throwing position, obtain a new snow-throwing direction based on the modification information of the snow-throwing position and the current position; readjust the snow-clearing path according to the new snow-throwing direction to obtain a target planning path; control the automatic snow-clearing machine to automatically walk based on the target planning path.

[0090] It should be noted that during the walking process of the automatic snow-clearing machine or before executing the walking, the user may need to change the previous snow-throwing position, or after the machine determines that the current snow-throwing position is no longer suitable as the snow-throwing position, re-determine a new snow-throwing position, generate a new snow-throwing direction based on the new snow-throwing position and the current position point of the machine, determine the potential energy of each grid in the snow-clearing map based on the new snow-throwing direction, and determine the target planning path based on the potential energy of each grid to determine that the new figure-eight snow-clearing path is a reasonable and most efficient path.

[0091] In the third embodiment, after the step S40, the following is further included:

[0092] Step S60: Determine the position deviation information of the automatic snow sweeper according to the integrated positioning information of the automatic snow sweeper; adjust the position of the fuselage to the position on the snow sweeping path by means of PID control based on the position deviation information of the automatic snow sweeper.

[0093] It should be noted that the integrated positioning information may be positioning information obtained based on multiple sensors and GPS-RTK;

[0094] It should be understood that during the walking process of the automatic snow sweeper, the position deviation of the fuselage movement may occur due to the snow accumulation on the ground (that is, deviating from the originally specified path). Therefore, the fuselage needs to be linearly controlled. Among them, linear control means that when driving along a straight road, the driver will focus on a relatively far point on the forward route to ensure that the car can drive along a straight line. Therefore, the automatic snow sweeper also considers using this method.

[0095] In a specific implementation, the position of the robot is adjusted based on the position deviation information and the PID method. Among them, the position deviation information refers to the deviation data formed with the original path direction. For example, if the current movement direction of the automatic snow sweeper is direction 1 and the fixed direction in the path is direction 2, the angular velocity needs to be adjusted to adjust direction 1 to direction 2. In addition, during the adjustment of the angular velocity, the linear velocity also needs to be adjusted. The greater the adjustment of the angular velocity (adjusted in the way of turning in place, the greater the adjustment angle, the greater the angular velocity), the smaller the adjustment of the linear velocity. Generally, the magnitude of the linear velocity is defaulted to 0.3 m / s, the maximum is 0.4 m / s, and the minimum is 0.2 m / s.

[0096] Further, the adjusting the position of the fuselage to the position on the snow sweeping path by means of PID control based on the position deviation information of the automatic snow sweeper includes:

[0097] Determine the deviation angle of the automatic snow sweeper according to the current point of the automatic snow sweeper and the target point on the snow sweeping path;

[0098] Determine the linear velocity and angular velocity of the automatic snow sweeper based on the deviation angle of the automatic snow sweeper;

[0099] Adjust the position of the fuselage on the snow sweeping path based on the linear velocity and angular velocity of the automatic snow sweeper.

[0100] It should be understood that the current point refers to the position point of the automatic snow sweeper on the snow sweeping path at present. At the beginning, the position point is the starting point; the target point is the position point that the automatic snow sweeper needs to reach on the planned snow sweeping path.

[0101] More specifically, the control logic of the PID method is as follows: Assume that the starting point (current point) is A, the target point is B, the point of the machine is C, the projection point of point C on the straight line AB is C', the target location point is D (D is on the straight line AB, and the distance from C' is adjustable from 0.2 m to 1 m), the body orientation angle is phi, and the theta value of the pid control is the angle between the body orientation and the target straight line CD, that is, the deviation value of the automatic snow sweeper: theta = A (current machine heading angle) - B{CD}; Angular velocity: rev = Kp * theta + Ki * integral (integral of the deviation value) + Kd * derivative (derivative of the deviation value); Linear velocity: vel = preset maximum speed * sqrt{1 - (rev / preset maximum angular velocity)^2}; where Kp, Ki, and Kd all belong to parameters.

[0102] In the third embodiment, after the step S40, it further includes:

[0103] Step S70: During the automatic walking process of the automatic snow sweeper, adjust the spacing in the snow sweeping path according to the thickness of the snow, and re-plan the snow sweeping path based on the adjusted spacing.

[0104] It should be noted that in the case of relatively thick snow, since it is more laborious for the machine to push, the spacing of the figure-eight sweep in the planned path can be adjusted smaller at this time to facilitate the machine's walking; in the case of relatively thin snow, the spacing of the figure-eight sweep in the planned path can be adjusted larger at this time; in addition, the current in the coil shovel motor can be used to determine the current thickness of the snow. When the snow is thicker, the required current is greater. Among them, the maximum spacing of the figure-eight sweep of the automatic snow sweeper is the width of the snow shovel head.

[0105] It should be understood that the spacing of the figure-eight sweep of the automatic snow sweeper can be adjusted by the user. The current thickness of the snow can be determined by a vision sensor or a lidar. Among them, the vision sensor or the lidar can identify the distance between two points on the same vertical plane to determine the current thickness of the snow. The snow sweeping speed can be adjusted according to the thickness of the snow. If the current of the snow coil shovel is large, it means that the load is large. At this time, the speed needs to be reduced to ensure clean cleaning and no overcurrent under full load.

[0106] In the third embodiment, after the step S40, it further includes:

[0107] Step S80: During the automatic walking process of the automatic snow sweeper, after determining that there is an obstacle affecting the movement on the snow sweeping path, control the automatic snow sweeper to bypass the obstacle and return to the snow sweeping path to continue walking.

[0108] It should be noted that during walking, obstacles can be determined through a vision sensor, a lidar, or a millimeter-wave radar. In this embodiment, obstacles can be determined through a collision sensor. Among them, some obstacles may be hidden in the snow and can only be determined after being touched during the robot's walking. After a collision occurs in the collision sensor, it is determined whether the obstacle is a living thing through a vision sensor, a lidar, or an infrared temperature sensor. When it is not a living thing, the obstacle is bypassed and the robot returns to the planned path. When it is a living thing, the movement stops. Understandably, detecting living things is to prevent the machine from causing harm to living things and ensure the safety of the machine. After a collision occurs in the collision sensor, the movement stops, and after receiving the user's confirmation information, the movement resumes.

[0109] Under normal circumstances, there can be multiple cameras on the automatic snow sweeper, which are respectively installed in the front, left, and right positions of the automatic snow sweeper to monitor the environment in different directions. Among them, the specific method of determining that a living thing detected by the camera is a human can be as follows: when a pedestrian appears within 5 meters in front of the front camera, the automatic plan is paused, the snow plow is stopped, and the machine gives a voice prompt for pedestrian detection; when a pedestrian appears within 5 meters in the left camera and the snow is thrown to the left, the automatic plan is paused, the snow plow is stopped, and the machine gives a voice prompt for pedestrian detection; when a pedestrian appears within 5 meters in the right camera and the snow is thrown to the right, the automatic plan is paused, the snow plow is stopped, and the machine gives a voice prompt for pedestrian detection.

[0110] In the third embodiment, when receiving the modified information of the snow throwing position, the automatic snow sweeper calculates a new snow throwing direction based on this new information and its current position. This can ensure that the machine operates according to the latest snow throwing requirements. Based on the new snow throwing direction, the snow sweeping path is readjusted to generate a target planned path. This can guarantee the coverage and uniformity of snow throwing, enabling the snow to be effectively cleared. Based on the target planned path, the automatic snow sweeper will walk automatically. Through the built-in navigation and positioning system, the machine can perceive its own position in real time, adjust the traveling direction, speed, and trajectory to ensure accurate walking along the planned path. During the automatic walking process, the automatic snow sweeper adjusts its position according to the fused positioning information to maintain its accurate position on the snow sweeping path. This RTK-odometry-IMU fused positioning information can include information such as GPS, inertial measurement unit (IMU), and odometer. According to the thickness of the snow, the automatic snow sweeper can dynamically adjust the spacing in the snow sweeping path. If the snow layer is thick, the spacing can be appropriately increased to improve the snow clearing efficiency. Conversely, if the snow layer is thin, the spacing can be reduced to ensure that the snow can be completely cleared. During the automatic walking process, if an obstacle affecting movement is detected, the automatic snow sweeper makes a judgment based on the sensor information and performs an operation to bypass the obstacle. Once the obstacle is bypassed, the machine will return to the snow sweeping path and continue walking, maintaining the planned snow clearing trajectory. Combining the above processes, the automatic snow sweeper can make intelligent adjustments according to various information and situations to achieve efficient, accurate, and autonomous snow sweeping tasks. This adaptability and flexibility can improve work efficiency in different snow clearing scenarios and ensure the safety and reliability of the snow sweeping operation.

[0111] In addition, referring to Figure 6 , an embodiment of the present invention further provides a path planning device, where the path planning device includes:

[0112] A position acquisition module 10, configured to acquire the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map;

[0113] A direction acquisition module 20, configured to determine the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position;

[0114] A path acquisition module 30, configured to plan a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction;

[0115] A walking execution module 40, configured to control the automatic snow sweeper to walk automatically based on the snow sweeping path.

[0116] In this embodiment, the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map are obtained; the snow throwing direction of the automatic snow sweeper is determined based on the snow throwing position and the current position; a snow sweeping path conforming to a preset rule is planned in the snow sweeping map based on the snow throwing direction; and the automatic snow sweeper is controlled to automatically travel based on the snow sweeping path, so that the automatic snow sweeper optimally plans the snow sweeping path and improves the snow sweeping efficiency of the automatic snow sweeper.

[0117] For other embodiments or specific implementation manners of the path planning device of the present invention, reference may be made to the above method embodiments, which will not be elaborated herein.

[0118] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the phrase "including a..." does not exclude the presence of additional identical elements in the process, method, article or system including the element.

[0119] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments. Among the several apparatus claims listing several units, several of these apparatuses may be embodied by the same hardware item. The use of the terms first, second, and third, etc. does not denote any order and these terms may be construed as names.

[0120] Through the description of the above embodiments, those skilled in the art can clearly understand that the above method embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation manner. Based on such an understanding, the technical solution of the present invention, in essence, or the part that makes a contribution to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as a Read Only Memory image (ROM) / Random Access Memory (RAM), magnetic disk, optical disk), and includes several instructions for causing a terminal user device (which may be a mobile phone, a computer, a server, an air conditioner, or a network user device, etc.) to execute the methods described in the various embodiments of the present invention.

[0121] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A path planning method, characterized in that, The method includes: Obtaining the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map; Determining the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position; Planning a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction. The snow sweeping path of the preset rule includes a path with high or low potential energy or a snow sweeping path formed after being blocked by an obstacle. The high or low potential energy refers to the distance and direction of the automatic snow sweeper from the snow throwing position; Controlling the automatic snow sweeper to automatically move based on the snow sweeping path; Wherein, before obtaining the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map, it further includes: Obtaining the longitude and latitude coordinates of the target snow throwing area and the target snow sweeping area through the fusion positioning technology of multiple sensors, and converting the longitude and latitude coordinates into a snow sweeping map coordinate system based on the origin, and the origin is the charging point; Rasterizing and potential fieldizing the target snow throwing area and the target snow sweeping area based on the snow sweeping map coordinate system to generate a snow sweeping map. Rasterizing and potential fieldizing the target snow throwing area and the target snow sweeping area means dividing the target snow throwing area and the target snow sweeping area into multiple grids, and setting a corresponding potential energy value for each grid through the breadth-first search algorithm; The step of setting a corresponding potential energy value for each grid through the breadth-first search algorithm includes: Marking the category of the grid, bundling a series of connected snow throwing grids together and marking them as a group. According to the upper, lower, left, and right boundaries of the group, finding the most suitable direction for spreading potential energy, marking the grids in the same row as the same potential energy starting from the lowest row, and incrementally marking the potential energy row by row in the spreading direction until the boundary is reached. The spreading adopts the breadth-first search algorithm. If the entire area is spread in a single time, the potential fieldization is completed. Otherwise, taking the grids at the spreading boundary as the new snow throwing positions, continue to execute the step of marking the grids in the same row as the same potential energy starting from the lowest row and incrementally marking the potential energy row by row in the spreading direction until the boundary is reached. The categories of the grids include cleaning, uncleaned, restricted area, and snow throwing position; After controlling the automatic snow sweeper to automatically move based on the snow sweeping path, it further includes: After an obstacle blocks the automatic snow sweeper from throwing snow to the snow throwing position, throwing the snow to an uncleaned area where the snow can be correctly thrown to the snow throwing position, and then throwing the snow to the snow throwing position through this area, or in an area where multiple partitions are formed in the working area, throwing the snow to the snow throwing position through the communication domain between each area.

2. The method according to claim 1, characterized in that, Planning a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction, including: Judging whether there are multiple snow sweeping areas in the snow sweeping map; If there are multiple snow sweeping areas, judging whether the multiple snow sweeping areas form a connected domain; If a connected domain is formed, determining the connection route of the area passed between two adjacent snow sweeping areas; Planning a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction and the connection route.

3. The method according to claim 1, characterized in that After controlling the automatic snow sweeper to automatically move based on the snow sweeping path, it further includes: When receiving the modification information of the snow throwing position, obtain a new snow throwing direction based on the modification information of the snow throwing position and the current position; Re-adjust the snow sweeping path according to the new snow throwing direction to obtain a target planning path; Control the automatic snow sweeper to walk automatically based on the target planning path.

4. The method according to claim 1, wherein After controlling the automatic snow sweeper to walk automatically based on the snow sweeping path, it further includes: Determine the position deviation information of the automatic snow sweeper according to the fusion positioning information of the automatic snow sweeper; Adjust the position of the fuselage to the position on the snow sweeping path based on the position deviation information of the automatic snow sweeper through the PID control method.

5. The method according to claim 4, wherein Adjusting the position of the fuselage to the position on the snow sweeping path based on the position deviation information of the automatic snow sweeper through the PID control method includes: Determine the deviation angle of the automatic snow sweeper according to the current point of the automatic snow sweeper and the target point on the snow sweeping path; Determine the linear velocity and angular velocity of the automatic snow sweeper based on the deviation angle of the automatic snow sweeper; Adjust the position of the fuselage on the snow sweeping path based on the linear velocity and angular velocity of the automatic snow sweeper.

6. The method according to claim 1, wherein After controlling the automatic snow sweeper to walk automatically based on the snow sweeping path, it further includes: During the automatic walking of the automatic snow sweeper, adjust the spacing in the snow sweeping path according to the thickness of the snow, and re-plan the snow sweeping path based on the adjusted spacing.

7. The method according to claim 1, characterized in that, After controlling the automatic snow sweeper to walk automatically based on the snow sweeping path, it further includes: During the automatic walking of the automatic snow sweeper, after determining that there is an obstacle affecting the movement on the snow sweeping path, control the automatic snow sweeper to bypass the obstacle and return to the snow sweeping path to continue walking.

8. A path planning device, characterized in that, The device includes: A position acquisition module, configured to acquire the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map; A direction acquisition module, configured to determine the snow throwing direction of the automatic snow sweeper based on the snow throwing position and the current position; A path acquisition module, configured to plan a snow sweeping path that conforms to a preset rule in the snow sweeping map based on the snow throwing direction, where the preset rule snow sweeping path includes a path with potential energy highs and lows or a snow sweeping path formed after being blocked by an obstacle, and the high and low of the potential energy refers to the distance and direction of the automatic snow sweeper from the snow throwing position; A walking execution module, configured to control the automatic snow sweeper to walk automatically based on the snow sweeping path; Before acquiring the snow throwing position and the current position of the automatic snow sweeper in the snow sweeping map, it further includes: obtaining the longitude and latitude coordinates of the target snow throwing area and the target snow sweeping area through the fusion positioning technology of multiple sensors, converting the longitude and latitude coordinates into a snow sweeping map coordinate system based on the origin, where the origin is the charging point; rasterizing and potential fieldizing the target snow throwing area and the target snow sweeping area based on the snow sweeping map coordinate system to generate a snow sweeping map, and rasterizing and potential fieldizing the target snow throwing area and the target snow sweeping area means dividing the target snow throwing area and the target snow sweeping area into multiple grids, and setting a corresponding potential energy value for each grid through the breadth-first search algorithm; The step of setting a corresponding potential energy value for each grid through the breadth-first search algorithm includes: marking the categories of the grids, bundling a series of connected snow-throwing grids together and marking them as a group, finding the most suitable direction for spreading potential energy according to the upper, lower, left, and right boundaries of the group, marking the grids in the same row as the same potential energy starting from the lowest row, incrementally marking the potential energy row by row in the spreading direction until the boundary is reached. The spreading uses the breadth-first search algorithm. If the entire area is spread in a single time, the potential field formation is completed. Otherwise, using the grids at the spreading boundary as new snow-throwing positions, continue to execute the step of marking the grids in the same row as the same potential energy starting from the lowest row and incrementally marking the potential energy row by row in the spreading direction until the boundary is reached. The categories of the grids include cleaning, uncleaned, restricted area, and snow-throwing position; The walking execution module is further configured to, after an obstacle blocks the automatic snow sweeper from throwing snow to the snow-throwing position, throw the snow to an uncleaned area where the snow can be correctly thrown to the snow-throwing position, and then throw the snow to the snow-throwing position through this area, or in an area where multiple partitions are formed in the working area, throw the snow to the snow-throwing position through the communication domain between each area.

9. A snow sweeper, characterized in that, The snow sweeper includes: a walking device, a snow removal device, a vehicle body device, and a control device. The control device includes: a memory, a processor, and a path planning program stored on the memory and executable on the processor. The path planning program is configured to implement the steps of the path planning method according to any one of claims 1 to 7.

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