Obstacle-avoidance detouring method and system for agvs at automated wharf

Abstract

Disclosed in the present invention are an obstacle-avoidance detouring method and system for AGVs at an automated wharf. The method comprises the following steps: S1, an AGV which has failed or been deadlocked stopping, and communicating with a VMS to report a fault-induced stop; S2, the VMS delimiting a passage forbidden region for the AGV; S3, the VMS planning a forward oblique detouring path for subsequent AGVs; S4, checking whether the detouring path can detour the passage forbidden region, and if so, the AGVs detouring and driving away, and if not, entering step S5; S5, the VMS planning a backward oblique detouring path for the subsequent AGVs; S6, checking whether the detouring path is deadlocked, and if so, returning to step S2, and if not, the AGVs detouring and driving away; and S7, repeating steps S3 to S6 until all the AGVs detour and drive away. By means of the present invention, AGVs can detour a faulty AGV, and subsequent congestion is automatically solved, such that subsequent AGVs avoid a deadlock.

Description

An automated terminal AGV obstacle avoidance and detour method and system Technical Field

[0001] The present invention relates to an AGV control technology for an automated terminal, and more particularly to an obstacle avoidance and detour method and system for an AGV for an automated terminal. Background Art

[0002] After planning a route, the VMS (Horizontal Transport Management System) in an automated terminal issues instructions to the AGVs in sections, controlling their progress along the route. If an AGV malfunctions, it brakes to a stop. Because the preceding vehicle hasn't left, the instructions to the following AGVs only reach the rear of the preceding vehicle. After completing the instructions, the AGVs will approach the preceding vehicle, causing multiple AGVs to become stuck on the road. The VMS uses the A* or Dijkstra algorithm to plan routes. If there are no restricted zones, the route remains the same, and the congestion is not automatically resolved. Technical issues

[0003] In response to the above-mentioned defects in the prior art, the purpose of the present invention is to provide an automated terminal AGV obstacle avoidance and detour method and system, so that the AGV can bypass the faulty AGV and automatically resolve subsequent congestion, so that subsequent AGVs can avoid deadlock, or when deadlocked, they can automatically unlock the deadlock and detour. Technical Solutions

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A first aspect of the present invention provides an automated terminal AGV obstacle avoidance and detour method, comprising the following steps:

[0006] S1, the AGV stops due to a fault or deadlock, and reports the fault to the VMS system;

[0007] S2, the VMS system draws a no-go zone for the AGV;

[0008] S3, the VMS system plans a forward oblique detour path for the subsequent AGV;

[0009] S4, check whether the detour path can bypass the restricted area. If so, the AGV will detour and leave. If not, proceed to step S5;

[0010] S5, the VMS system plans a backward oblique detour path for the subsequent AGV;

[0011] S6, check whether the detour path is deadlocked, if so, return to step S2, if not, the AGV detours and leaves;

[0012] S7, repeat steps S3 to S6 until all the AGVs have bypassed the area.

[0013] Preferably, in step S3, the VMS system uses the Dijkstra algorithm to plan a detour path, specifically including:

[0014] First, find the edges that originate from the starting point and check whether they overlap with the forbidden area. Edges that overlap are discarded, and edges that do not overlap are saved.

[0015] Then, starting from the saved edges, find the connected edges, filter out the edges that do not overlap with the prohibited area, and save the edges with the shortest distance to the starting point;

[0016] Repeat until the end point is found, or all edges are saved and no end point is found.

[0017] Preferably, the VMS system applies for occupying a detour path in a Try-Claim manner, and sends a driving instruction to the AGV. The AGV drives according to the driving instruction and stops after driving the occupied detour path until it reaches the end point.

[0018] A second aspect of the present invention provides an automated terminal AGV obstacle avoidance and detour system, comprising:

[0019] VMS system, used to plan the starting and ending points of detour routes;

[0020] A restricted zone management module establishes data communication with the VMS system to draw a restricted zone for the AGV with a fault;

[0021] A map management module establishes data communication with the VMS system to establish a coordinate system;

[0022] AGV management module, establishing data communication with the VMS system to obtain signals from on-site AGV vehicles;

[0023] The automated terminal AGV obstacle avoidance and detour system implements the automated terminal AGV obstacle avoidance and detour method provided in the first aspect of the present invention.

[0024] Preferably, the VMS system includes a path planning module and a traffic control module.

[0025] Preferably, the map management module is used to divide the terminal site into sections of edges, each of which has a direction;

[0026] The edges are connected end to end;

[0027] A path consists of a set of edges connected end to end. Beneficial effects

[0028] The present invention provides an automated terminal automated guided vehicle (AGV) obstacle avoidance and detour method and system. Congested AGVs are individually surrounded by a no-go zone until the last AGV. Unobstructed by subsequent AGVs, its detour path is acceptable. After the last AGV leaves, the penultimate AGV can also detour and leave. The congested AGVs are detoured sequentially from back to front, thus unblocking the congestion. AGVs can bypass a faulty AGV and automatically resolve subsequent congestion, allowing subsequent AGVs to avoid deadlock or, if deadlocked, automatically unblock and detour. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic flow chart of an automated terminal AGV obstacle avoidance and detour method according to the present invention;

[0030] FIG2 is a schematic diagram of the framework structure of the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0031] FIG3 is a schematic diagram of the principle of the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0032] FIG4 is a schematic diagram of the organization of the map management module in the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0033] FIG5 is a schematic diagram of the path and Try-Claim usage of the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0034] FIG6 is a schematic diagram 1 of a path planning module using the Dijkstra algorithm in the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0035] FIG7 is a schematic diagram 2 of a path planning module using the Dijkstra algorithm in the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0036] FIG8 is a schematic diagram 3 of the path planning module using the Dijkstra algorithm in the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0037] FIG9 is a schematic diagram 4 of a path planning module using the Dijkstra algorithm in the automated terminal AGV obstacle avoidance and detour system of the present invention;

[0038] FIG10 is a schematic diagram 1 of the subsequent AGV trolley traveling along the path in the automated terminal AGV obstacle avoidance and detour method of the present invention;

[0039] FIG11 is a schematic diagram 2 of the subsequent AGV trolley traveling along the path in the automated terminal AGV obstacle avoidance and detour method of the present invention;

[0040] FIG12 is a schematic diagram 3 of the subsequent AGV trolley traveling along the path in the automated terminal AGV obstacle avoidance and detour method of the present invention;

[0041] FIG13 is a schematic diagram 4 of the subsequent AGV trolley traveling along the path in the automated terminal AGV obstacle avoidance and detour method of the present invention;

[0042] FIG14 is a schematic diagram 1 of a fault bypass method in an automated terminal AGV obstacle avoidance method according to the present invention;

[0043] FIG15 is a schematic diagram 2 of a fault bypass method in an automated terminal AGV obstacle avoidance method according to the present invention;

[0044] FIG16 is a schematic diagram 3 of a fault bypass method in an automated terminal AGV obstacle avoidance method according to the present invention;

[0045] FIG17 is a schematic diagram 4 of a fault bypass method in an automated terminal AGV obstacle avoidance bypass method according to the present invention;

[0046] FIG18 is a schematic diagram 1 showing a failure of the tail AGV to bypass the obstacle avoidance method of the automated terminal AGV according to the present invention;

[0047] FIG19 is a schematic diagram 2 showing a failure of the tail AGV to bypass the obstacle avoidance method of the automated terminal AGV according to the present invention;

[0048] FIG20 is a schematic diagram 1 showing a successful detour of the tail AGV in the automated terminal AGV obstacle avoidance detour method according to the present invention;

[0049] FIG21 is a schematic diagram 2 showing a successful detour of the tail AGV in the automated terminal AGV obstacle avoidance detour method according to the present invention;

[0050] FIG22 is a schematic diagram of two deadlocked paths in the automated terminal AGV obstacle avoidance and detour method of the present invention. Best Mode for Carrying Out the Invention

[0051] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to the accompanying drawings and embodiments.

[0052] As shown in FIG1 , the present invention provides an automated terminal AGV obstacle avoidance and detour method, comprising the following steps:

[0053] S1, the AGV stops due to a fault or deadlock, and reports the fault to the VMS system;

[0054] S2, the VMS system draws a no-go zone for the AGV that has failed or deadlocked (returned from step S6) to protect the AGV;

[0055] In step S3, the VMS system checks the AGVs that will pass through the restricted area on the subsequent paths and sorts them from near to far according to their distance from the restricted area. The VMS system processes the sorted AGVs in turn and plans forward oblique detour paths for the subsequent AGVs.

[0056] S4, check whether the detour path can bypass the restricted area without being blocked. If so, the AGV will detour and process the next AGV. If not, proceed to step S5;

[0057] S5, the VMS system plans a backward oblique detour path for the subsequent AGV;

[0058] S6, check whether the detour path is deadlocked, if so, return to step S2, if not, the AGV detours and leaves;

[0059] S7, repeat steps S3 to S6 until all AGVs have bypassed the area.

[0060] In step S3 above, the VMS system uses the Dijkstra algorithm to plan a detour route, and the map management module provides the edges connecting the end of the entire field, specifically including:

[0061] First, find the edges that originate from the starting point and check whether they overlap with the forbidden area. Edges that overlap are discarded, and edges that do not overlap are saved.

[0062] Then, starting from the saved edges, find the connected edges, and also select the edges that do not overlap with the prohibited area and the shortest edges to the starting point for saving;

[0063] Repeat until the end point is found (path planning is successful, the shortest path is found), or the end point is not found after all edges are saved (path planning fails).

[0064] The driving instructions issued by the VMS system to the AGV vehicle use the Try-Claim method to apply for occupying a detour path. The driving instructions are sent to the AGV vehicle. The AGV vehicle drives according to the driving instructions and stops after driving the occupied detour path until it reaches the final destination.

[0065] As shown in FIG2 and FIG3 , the second aspect of the present invention provides an automated terminal AGV obstacle avoidance and detour system, comprising:

[0066] VMS system 1, used to plan the starting point and end point of the detour route;

[0067] The restricted zone management module 2 establishes data communication with the VMS system 1 to draw a restricted zone for the AGV with a fault;

[0068] The map management module 3 establishes data communication with the VMS system 1 to establish a coordinate system;

[0069] The AGV management module 4 establishes data communication with the VMS system 1 to obtain signals from the on-site AGV;

[0070] The automated terminal AGV obstacle avoidance and detour system of the present invention realizes the automated terminal AGV obstacle avoidance and detour method of the present invention.

[0071] The VMS system 1 includes a path planning module 11 and a traffic control module 12 .

[0072] The AGV features navigation and basic laser obstacle avoidance capabilities. It reports its position and fault information to the VMS system 1 and executes driving instructions issued by the system. The VMS system 1 analyzes the task start and end points from the path planning module 11 and finds the corresponding coordinates on the map management module 3. The path planning module 11 then uses the Dijkstra algorithm to plan a path from the start point to the end point, avoiding restricted areas and achieving the optimal path (shortest distance first).

[0073] As shown in Figures 4 and 5 , the map management module 3 divides the terminal site into segments of edges with directions assigned to them. Each edge is connected end-to-end, and a path consists of a set of connected edges. AGVs follow these paths, and to ensure safety, they require Try-Claim protection. First, a Try attempt is made to occupy a segment of the path and check whether this segment conflicts with restricted areas or other AGV claims. If so, the Try fails. If not, the Try transitions to a Claim, indicating that the segment has been occupied.

[0074] As shown in Figures 6 to 9, the VMS system 1 uses the Dijkstra algorithm to plan the path. The map management module 3 provides the edges connecting the beginning and the end of the entire field. First, the edges emanating from the starting point are found and checked to see if they overlap with the restricted area. Edges that overlap are discarded, and edges that do not overlap are saved. Then, starting from the saved edges, connected edges are found. Edges that do not overlap with the restricted area are also selected, and the edges with the shortest path to the starting point are saved. The second step is repeated until the end point is found (path planning is successful, the shortest path is found), or all edges are saved but there is no end point (path planning fails).

[0075] As shown in Figures 10 to 13, the subsequent AGVs execute the driving instructions issued by the VMS system 1. The VMS system 1 uses the Try-Claim method to apply for occupying a section of the path and issues the driving instructions to the AGVs. The AGVs move forward according to the driving instructions and stop after completing the occupied path until they reach the end of the path.

[0076] As shown in Figures 14 to 17, V1, V2, and V3 are AGVs traveling from the right side of the diagram to the left. After V1 fails, V2 and V3 park behind V1. A no-go zone is drawn after V1 fails. When V2 attempts to claim, it detects the no-go zone, triggering a re-route plan. When V2 uses the Dijkstra algorithm to plan its path, the forward edge is affected by V1's no-go zone and fails. However, the backward edge is unaffected, so the path planning succeeds. V2's re-planned path interferes with V3's, causing V2's try-claim to fail. However, the no-go zone is not detected, so V2 continues to wait.

[0077] As shown in Figures 18 and 19, after V1 fails, V2 and V3 park behind V1. There are no AGVs behind V3. As shown in the figure, V3 uses the Dijkstra algorithm to plan a path, but its forward attempt is interfered with by V2. However, V2 is a functioning AGV, and before the no-go zone is drawn, V3's attempt is successful. V3 also uses the Dijkstra algorithm to plan a path, but the generated path is interfered with by V2, and V3 still cannot bypass it.

[0078] As shown in Figures 20 and 21, V3 uses the Dijkstra algorithm to plan its path. Its forward attempt is interfered with by V2, which has already drawn a no-go zone. Therefore, the forward attempt fails, but the backward attempt succeeds. V3 also uses the Dijkstra algorithm to plan its path, generating a path that is free of interference from V2, allowing V3 to successfully bypass the route.

[0079] As shown in Figure 22, V2 and V3 claim their own locations respectively. V2's Try passes through V3's Claim, and V3's Try passes through V2's Claim. Based on this, it can be determined that the paths of V2 and V3 constitute a deadlock.

[0080] Deadlock means that the next displacement of each AGV in the set is waiting for other AGVs in the set to leave the current position, then the group of AGVs is deadlocked. Modes for Carrying Out the Invention

[0081] Referring again to FIG1 , the obstacle avoidance and detour method for an automated terminal AGV in this embodiment specifically includes the following steps:

[0082] S1, the AGV car stops due to a fault. The AGV car will communicate with the VMS system to report the fault stop;

[0083] S2: The VMS system receives the AGV's fault (or deadlock) parking information and draws a no-go zone around the faulty AGV to protect it.

[0084] In step S3, the VMS system checks the AGVs that will pass through the restricted zone on subsequent paths and sorts them from nearest to farthest according to their distance from the restricted zone. The VMS system processes the sorted AGVs in sequence, first planning a detour path that moves diagonally forward to the adjacent lane.

[0085] S4, checking whether the detour path can bypass the prohibited area without being blocked;

[0086] S5: If possible, the AGV will detour and jump to step S3 to process the next AGV; if not, a detour path will be planned to go diagonally backward to the adjacent lane;

[0087] S6, check whether the detour path forms a deadlock with its subsequent AGV path;

[0088] S7: If deadlock does not occur, the AGV will detour and jump to step 3 to process the next AGV; if deadlock occurs, the VMS system will wait for the AGV to stop.

[0089] S8, the VMS system receives the AGV stop message and draws a no-go zone around the AGV to protect it;

[0090] S9, repeat steps S2 to S8 until all AGVs have bypassed and left.

[0091] In summary, in the automated terminal AGV obstacle avoidance and detour method of the present invention, the VMS system plans the path to avoid the restricted area (the area where non-local AGVs are prohibited from entering). Therefore, when a faulty AGV is detected, the VMS system automatically generates a restricted area that encloses the faulty AGV, and the VMS system generates a path for subsequent AGVs to bypass the faulty AGV. If the subsequent AGV is already close to the faulty AGV, the planned path is to go diagonally backward to the adjacent lane, and then plan a path forward to bypass the faulty AGV. Then, the newly planned path When the path goes diagonally backward, it may form a deadlock with the forward path of the subsequent AGV car. Such a detour path is also unacceptable, so the VMS system will automatically generate a no-entry zone to wrap it; the congested AGV cars will be wrapped with no-entry zones one by one until the last AGV car. Because there is no obstruction from subsequent AGV cars, its detour path is acceptable. After the last AGV car leaves, the penultimate AGV car can also detour and leave. The congested AGV cars detour and leave in order from back to front, so the congestion is resolved.

[0092] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. An automated terminal AGV obstacle avoidance and detour method, characterized in that: The following steps are involved: S1, the AGV stops due to a fault or deadlock, and reports the fault to the VMS system; S2, the VMS system draws a no-go zone for the AGV; S3, the VMS system plans a forward oblique detour path for the subsequent AGV; S4, check whether the detour path can bypass the prohibited area, if so, the AGV detours and leaves, if not, proceed to step S5; S5, the VMS system plans a backward oblique detour path for the subsequent AGV; S6, check whether the detour path is deadlocked, if so, return to step S2, if not, the AGV detours and leaves; S7, repeat steps S3 to S6 until all the AGVs have bypassed and left.

2. The automated terminal AGV obstacle avoidance and detour method according to claim 1 is characterized in that: In step S3, the VMS system uses the Dijkstra algorithm to plan a detour path, which specifically includes: First, find the edges from the starting point and check whether these edges overlap with the forbidden area. The edges with overlap are discarded, and the edges without overlap are saved. Then, starting from the saved edges, find the connected edges, filter out the edges that do not overlap with the forbidden area, and save the shortest edges to the starting point; Repeat until the end point is found, or all edges are saved and no end point is found.

3. The automated terminal AGV obstacle avoidance and detour method according to claim 2 is characterized by: The VMS system applies for occupying a detour path in a Try-Claim manner, and sends a driving instruction to the AGV. The AGV drives according to the driving instruction and stops after driving the occupied detour path until it reaches the end point.

4. An automated terminal AGV obstacle avoidance and detour system, characterized in that: include: VMS system, used to plan the starting and ending points of the detour route; A no-go zone management module establishes data communication with the VMS system to draw a no-go zone for the AGV vehicle with a fault; A map management module establishes data communication with the VMS system to establish a coordinate system; The AGV management module establishes data communication with the VMS system to obtain the signal of the on-site AGV car; The automated terminal AGV obstacle avoidance and detour system implements the automated terminal AGV obstacle avoidance and detour method as described in any one of claims 1-3.

5. The automated terminal AGV obstacle avoidance and detour system according to claim 4 is characterized by: The VMS system includes a path planning module and a traffic control module.

6. The automated terminal AGV obstacle avoidance and detour system according to claim 4 is characterized by: The map management module is used to divide the dock site into sections of edges, with directions set on the edges; The edges are connected end to end; A path consists of a set of edges connected end to end.

Images