AGV road area dynamic blocking and unblocking system and control method thereof

Abstract

The present application relates to the technical field of automatic guided vehicle, and discloses an AGV road area dynamic blocking and unblocking system and a control method thereof, the AGV road area dynamic blocking and unblocking system comprises a locking trigger, an unblocking trigger, an indicator light unit, a controller, an area sensor, an AGV navigation system and an AGV, a target area is arranged at the intersection of a sidewalk and a main road, the locking trigger and the unblocking trigger are arranged outside the target area and at both ends of the sidewalk respectively, the indicator light unit is arranged in the target area and at both ends of the sidewalk, the area sensor is arranged in the target area and scans the target area, the controller is connected with the locking trigger, the unblocking trigger, the indicator light unit, the area sensor and the AGV navigation system respectively, and the AGV navigation system is connected with the AGV.The present application can shorten the blocking / unblocking response time of the target area to within 10 seconds, avoid the information lag problem of the traditional scheme, reduce the overall system scheduling efficiency loss, and reduce the operating cost without manual intervention reset.

Description

Technical Field

[0001] This invention relates to the technical field of automated guided vehicles, and more particularly to an AGV road area dynamic blocking and unblocking system and its control method. Background Technology

[0002] AGVs (Automated Guided Vehicles) are transport vehicles that navigate automatically using systems such as lasers, magnetic strips, and vision, and are widely used in modern logistics and industrial automation. Currently, existing systems primarily employ two methods to address the need for temporary road closures: 1. Remote control via scheduling software: This relies on personnel at the scheduling center to remotely operate the software and modify the AGV's path. This method requires continuous monitoring and operation by dedicated personnel, wasting manpower and potentially leading to delayed responses due to human intervention or communication latency (traditional cloud-based scheduling may have a delay of 200-500ms). 2. Using physical barriers: For example, setting up fences or other obstacles. This method requires the AGV to actively identify and avoid obstacles, significantly reducing its operating efficiency. More seriously, if the AGV fails to successfully identify the fence, it may mistakenly enter the closed area, causing collisions with personnel or other equipment and resulting in safety injuries. The main shortcomings of existing AGV systems for temporarily closing road areas can be summarized as: reliance on manual intervention and delayed response: Whether through remote software operation or manual placement of physical barriers, both rely on human intervention, which is prone to response delays and affects overall operational efficiency. Impact on overall system efficiency: Software-based blocking solutions often require suspending the entire AGV system or forcing manual takeover of AGV operation, disrupting the original scheduling rhythm and causing traffic congestion and production interruptions. Safety hazards exist: If physical fences are not reliably recognized by the AGVs, collisions may occur. Summary of the Invention

[0003] The purpose of this invention is to overcome at least one of the shortcomings of the prior art and to provide an AGV road area dynamic blocking and unblocking system and its control method.

[0004] The objective of this invention is achieved through the following technical solution: an AGV road area dynamic blocking and unlocking system, applied to sidewalks, main roads, and target areas where sidewalks and main roads intersect. The system includes a locking trigger, an unlocking trigger, an indicator light unit, a controller, an area sensor, an AGV navigation system, and an AGV. The locking trigger and the unlocking trigger are respectively located outside the target area and at both ends of the sidewalk. The indicator light unit is located in the target area and at both ends of the sidewalk. The area sensor is located in the target area and scans the target area. The controller is connected to the locking trigger, the unlocking trigger, the indicator light unit, the area sensor, and the AGV navigation system. The AGV navigation system is connected to the AGV. The controller receives signals from the locking trigger or the unlocking trigger and issues blocking or unlocking commands to the AGV guidance system. The AGV navigation system plans a path and controls the AGV in real time according to the blocking or unlocking commands from the controller.

[0005] Preferably, the area sensor includes a radar and a photoelectric switch, wherein the radar is used to scan dynamic targets and the photoelectric switch is used to detect static obstacles.

[0006] Preferably, the area sensor is a camera.

[0007] Preferably, both the locking trigger and the unlocking trigger are facial recognition sensors.

[0008] Preferably, the locking trigger and the unlocking trigger are work card authentication buttons.

[0009] Preferably, the sidewalk and the main road are also connected by an auxiliary road.

[0010] A control method for an AGV road area dynamic blocking and unlocking system includes the following steps:

[0011] S1. The operator is at the entrance of the pedestrian walkway and triggers the locking trigger. The controller receives the blocking request signal from the locking trigger and issues an instruction to the area sensor.

[0012] S2. The area sensor confirms whether there is a dynamic target in the target area of ​​the main road. If not, the indicator light unit is in a green light state and the operator can pass through the target area directly. Otherwise, proceed to step S5.

[0013] S3. The operator is at the exit of the pedestrian walkway and triggers the release trigger. The controller receives the release request signal from the release trigger and issues an instruction to the area sensor.

[0014] S4. The area sensor confirms whether there are dynamic targets and static obstacles in the target area of ​​the main road. If not, the indicator light unit is in a red light state and the AGV passes directly through the target area; otherwise, proceed to step S5.

[0015] S5. After executing the exception handling mechanism to clear the dynamic target, return to step S2. After executing the exception handling mechanism to clear the dynamic target or static obstacle, return to step S4.

[0016] Preferably, step S2 specifically includes the following steps:

[0017] S201. The area sensor scans the target area of ​​the main road to see if there is a dynamic target. If not, proceed to step S202; otherwise, proceed to step S5.

[0018] S202, the controller sends a blocking command to the AGV navigation system. At the same time, the controller controls the green light of the indicator unit to be constantly on. The AGV navigation system sets the target area as a dynamic restricted area. The AGV guidance system excludes the coordinates of the dynamic restricted area and plans the path in real time. The AGV moves according to the real-time planned path.

[0019] Preferably, step S4 specifically includes the following steps:

[0020] S401. The area sensor confirms whether there are dynamic targets and static obstacles in the target area of ​​the main road. If not, proceed to step S402; otherwise, proceed to step S5.

[0021] S402, the controller sends a release command to the AGV navigation system and instructs the indicator light unit to be in a constant red light state. The AGV navigation system deletes the coordinates of the target area of ​​the restricted area and plans the shortest path. The AGV directly passes through the target area according to the shortest path.

[0022] Preferably, the exception handling mechanism in step S5 includes the following steps:

[0023] S501. When the target area is a dynamic restricted area and there is an AGV, the indicator light unit is in a flashing green light state, and the area sensor periodically scans the AGV until the AGV leaves the target area and then executes step S2.

[0024] S502. When the target area is a safe area and there are dynamic targets or static obstacles, the indicator light unit is in a red flashing state, the area sensor detects and scans dynamic targets or static obstacles, and executes step S4 after there are no dynamic targets or static obstacles in the target area.

[0025] The present invention has the following advantages and beneficial effects compared with the prior art:

[0026] This invention provides an AGV road area dynamic blocking and unlocking system and its control method, enabling one-click triggering of target area blocking and unlocking. This replaces manual placement of isolation devices or software operation, reducing the blocking / unblocking response time of the target area from 3-5 minutes in traditional solutions to within 10 seconds, ensuring personnel safety. It employs millimeter-wave radar and photoelectric switches for dual-mode verification, improving system safety and feasibility. Indicator light units directly map the real-time status of the target area, allowing operators to intuitively observe its status and avoiding the information lag problem of traditional solutions. No AGV modification is required, reducing costs. When the target area is blocked, the AGV navigation system only replans the path to the target area, allowing normal operation in non-blocked areas of the main road (excluding the target area), reducing overall system scheduling efficiency loss. Area sensors automatically and periodically scan or detect without manual intervention, further reducing operating costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the use of an AGV road area dynamic blocking and unblocking system according to the present invention;

[0028] Figure 2 This is a connection diagram of an AGV road area dynamic blocking and unblocking system according to the present invention;

[0029] Figure 3 This is a flowchart of a control method for an AGV road area dynamic blocking and unblocking system according to the present invention;

[0030] Figure 4 This is a flowchart of the abnormal handling mechanism of the control method of the AGV road area dynamic blocking and unblocking system of the present invention;

[0031] The components in the attached diagram are labeled as follows: 1-AGV; 2-Main road; 3-Auxiliary road; 4-Indicator light unit; 5-Lock trigger; 6-Release trigger; 7-Area sensor; 8-Walking personnel; 9-Static obstacles; 10-Pedestrian walkway; 1001-Entrance; 1002-Exit; 11-Target area. Detailed Implementation

[0032] The invention's objective will be further described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the implementation of the invention is not limited to the following embodiments.

[0033] Example 1

[0034] Traditional methods rely on manual placement or removal of physical barriers or remote scheduling software, resulting in time-consuming blocking or unblocking processes (averaging 3-5 minutes), which cannot meet the rapid response requirements of temporary operations. This embodiment uses a physical button on-site for one-click triggering, reducing the operation time to within 10 seconds, achieving "instant response." Traditional solutions lack a real-time status feedback mechanism, making it impossible for operators to intuitively determine whether an area is safe (e.g., accidentally entering an area that has not been unblocked), and the AGV1 scheduling system cannot perceive the intention of manual operation. This embodiment introduces a dual-color indicator light unit 4, using color to distinguish whether the target area is safe: a solid green indicator light unit 4 indicates that the target area is blocked, and personnel 8 can work safely; a solid red indicator light unit 4 indicates that the blockade of the target area 11 has been lifted, and the AGV can pass through the target area 11. Existing software blocking solutions often require pausing the entire AGV1 system or forcing the AGV1 to take a long detour, resulting in a scheduling efficiency decrease of more than 30%. This embodiment is based on dynamic path replanning technology. After receiving instructions from the controller, the AGV navigation system only avoids the blocked target area 11; AGVs in non-blocked areas continue to run along their original paths; and the optimal path is automatically restored after the blockage is lifted. It maintains seamless compatibility with existing AGV scheduling systems and does not affect overall scheduling efficiency. This embodiment's AGV road area dynamic blockage and unblocking system has a self-recovery characteristic. When indicator light unit 4 is in an abnormal flashing mode, the system automatically retryes periodically until the conditions are met, seamlessly connecting to the main process without manual intervention.

[0035] like Figure 1 and 2 As shown, an AGV road area dynamic blocking and unlocking system includes a locking trigger 5, an unlocking trigger 6, two indicator light units 4, a controller, and two area sensors 7; each area sensor 7 includes a radar and a photoelectric switch. A pedestrian walkway 10 intersects perpendicularly with a main road 2, and the upper end of the main road 2 is connected to the exit 1002 of the pedestrian walkway 10 via an auxiliary road. A target area 11 is located at the intersection of the main road 2 and the pedestrian walkway 10. The locking trigger 5 and the unlocking trigger 6 are both located at the entrance of the pedestrian walkway 10 and on the left side of the target area 11, and at the exit 1002 of the pedestrian walkway 10 and on the right side of the target area 11. The two area sensors 7 are respectively installed at the connection between the main road 2 and the pedestrian walkway 10, and the two area sensors 7 can scan the entire target area 11. The two indicator light units 4 are respectively located outside the two area sensors 7 and are respectively installed on the pedestrian walkway 10. The controller is connected to the locking trigger 5, the unlocking trigger 6, the indicator light units 4, and the area sensors 7. The controller sends CAN commands through the RS485 circuit to control the AGV navigation system, which then dynamically plans routes for AGV1.

[0036] Lock trigger 5 outputs a high-level (5V) signal to the controller when pressed. Release trigger 6 also outputs a high-level (5V) signal to the controller when pressed. Indicator unit 4 includes a red light and a green light. A constantly lit green light indicates that the lock is active, and a constantly lit red light indicates that the lock is released. The real-time status of the target area 11 is indicated by the constantly lit or flashing red or green light at a flashing frequency of 1Hz. The controller is a microcontroller with an integrated RS485 / CAN bus interface. It receives signals from the area sensor 7, controls the constant or flashing status of the indicator unit 4, and issues lock / release commands to the AGV navigation system. Area sensor 7 monitors dynamic targets and static obstacles 9 within the target area. Dynamic targets are walking personnel 8 and AGV1, while static obstacles 9 are personnel in a crouching position or stagnant materials. Main road 2 is used for AGV1 transportation and represents the shortest path for AGV1. Pedestrian walkway 10 is used for personnel passage. Target area 11 consists of a portion of main road 2 and a portion of pedestrian walkway 10, used for pedestrians 8 or AGV1. The radar is a millimeter-wave radar with a scanning range of 0-5m, used to scan for dynamic targets within the target area. The photoelectric switch has a detection range of 0-5m and is used to detect static obstacles 9 within the target area. AGV1 can temporarily pass through auxiliary road 3 when target area 11 is blocked.

[0037] like Figure 3 and 4 As shown, a control method for an AGV road area dynamic blocking and unlocking system includes the following steps:

[0038] S1. The controller periodically scans the state of the locking trigger 5 with a period of 500ms. When the operator enters the pedestrian walkway 10 from the entrance 1001 and presses the locking trigger 5 at the entrance 1001, the controller receives the blocking request signal and issues an instruction to the area controller.

[0039] S2. After receiving the instruction, the area sensor 7 periodically scans the target area 11 of the main road 2 to confirm whether AGV1 exists in the target area 11. If AGV1 does not exist in the target area 11, the target area 11 is a dynamic restricted area (i.e., the target area 11 is in a blocked state), and the operator can pass through the target area 11 directly; otherwise, proceed to step S5. Step S2 specifically includes the following steps:

[0040] S201. The millimeter-wave radar of the area sensor 7 scans the target area 11 to see if there is a dynamic target, which is AGV1. If the number of dynamic targets in the target area 11 is 0, that is, there is no AGV1 in the target area 11, then step S202 is executed. If the number of dynamic targets in the target area 11 is greater than 0, that is, there is AGV1 in the target area 11, then step S5 is executed.

[0041] S202, the controller sends a blocking command to the AGV navigation system. The AGV navigation system sets the target area 11 as a dynamic restricted area. The AGV navigation system plans a path in real time, excluding the coordinates of the dynamic restricted area. AGV1 moves according to the real-time planned path, so that AGV1 avoids the dynamic restricted area (i.e., the target area). At the same time, the controller controls the green light of the indicator unit 4 to be in a constant state, indicating that the walking personnel 8 can pass through the target area 11.

[0042] S3. The operator triggers the release trigger 6 at the exit 1002. After the operator passes through the target area 11 from the entrance 1001 of the pedestrian walkway 10 and reaches the exit 1002, he / she presses the release trigger 6. The controller periodically scans the status of the release trigger 6 with a period of 500ms. The controller receives the release request signal and issues an instruction to the area sensor 7.

[0043] S4. The area sensor 7 confirms whether there are dynamic targets and static obstacles 9 in the target area 11 of the main road 2. If not, that is, the target area 11 is a safe area, and the AGV1 passes directly through the target area 11; otherwise, proceed to step S5. Step S4 specifically includes the following steps:

[0044] S401. The millimeter-wave radar of the area sensor 7 scans the target area 11 to see if there is a dynamic target, which is a walking person 8; the photoelectric switch of the area sensor 7 detects whether there is a static obstacle 9 in the target area 11, which includes personnel in a squatting position and stagnant materials; if neither the millimeter-wave radar nor the photoelectric switch is triggered, then step S402 is executed, otherwise step S5 is executed.

[0045] S402, the controller clears the temporary storage of the blockage flag, waits for the next trigger, and sends a release command to the AGV navigation system. Simultaneously, the controller instructs indicator light unit 4, causing its red light to remain constantly on, indicating that the walking personnel 8 cannot enter the target area 11. The coordinates of the target area 11 are deleted from the restricted area coordinates of the AGV navigation system. The AGV navigation system triggers "A* algorithm replanning" (the AGV system's built-in algorithm) to plan the shortest path, and AGV1 directly passes through the target area 11 according to the shortest path.

[0046] S5. After the exception handling mechanism removes the dynamic target, return to step S2; after removing the dynamic target or static obstacle, return to step S4. The exception handling mechanism in step S5 includes the following steps:

[0047] S501. When the target area 11 is a dynamic restricted area and AGV1 is present, the green light of the indicator unit 4 is flashing. The controller commands the millimeter-wave radar of the area sensor 7 to periodically scan AGV1 every 2 seconds. The operator does not need to repeatedly press the locking trigger 5 until AGV1 leaves and executes step S2.

[0048] S502. When the target area 11 is a safe area and there are walking personnel 8, personnel in a squatting position, or leftover materials, the controller sends a command to the indicator light unit 4. The red light of the indicator light unit 4 flashes to remind the walking personnel 8 to evacuate. The millimeter-wave radar of the area sensor 7 rescans the walking personnel 8 in the target area 11 every 2 seconds. The photoelectric switch of the area sensor 7 detects personnel in a squatting position or leftover materials every 10 seconds until there are no more walking personnel 8, personnel in a squatting position, or leftover materials in the target area 11, then proceed to step S4.

[0049] Beneficial effects of an AGV road area dynamic blocking and unlocking system and its control method:

[0050] 1. Innovative ease of operation: The target area 11 can be locked with one click by locking trigger 5 and unlocked with one click by releasing trigger 6, replacing manual placement of isolation devices or software operation, reducing the lock / unlock response time of target area 11 from 3 to 5 minutes in the traditional solution to within 10 seconds.

[0051] 2. Dual-mode verification using millimeter-wave radar and photoelectric switches: Millimeter-wave radar detects dynamic targets (including AGV1 or walking personnel 8); photoelectric switches cover static obstacles 9 (workers in a crouching position or stagnant materials), improving the safety of the system.

[0052] 3. Real-time visual feedback: The indicator light unit 4 directly maps the real-time status of the target area 11, avoiding the information lag problem of traditional solutions.

[0053] 4. System compatibility advantages: The controller connects to the AGV navigation system through a standard communication protocol, without the need to modify the existing AGV1 hardware, and is compatible with mainstream scheduling platforms.

[0054] 5. Adopt dynamic local avoidance technology: When the target area 11 is blocked, the AGV navigation system only replans the path of the target area 11, and can operate normally in the non-blocked area of ​​the main road 2 (excluding the target area 11), reducing the overall system scheduling efficiency loss.

[0055] 6. Self-recovery feature: In abnormal flashing mode (green light flashing or red light flashing), area sensor 7 automatically and periodically scans or detects until the conditions are met, then seamlessly connects to the main process without manual intervention.

[0056] Example 2

[0057] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0058] In this embodiment, a camera is used in place of millimeter-wave radar and photoelectric switch in target area 11. The camera is used to monitor dynamic targets and static obstacles 9, and directly feeds the information back to the controller. The camera enhances detection accuracy and replaces millimeter-wave radar and photoelectric switch to monitor the state of target area 11.

[0059] Example 3

[0060] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0061] In this embodiment, a face recognition sensor is used instead of the lock trigger 5 and the release trigger 6. The face recognition sensor is used to improve operational security and avoid unauthorized triggering through authentication (the response time is still kept within 10 seconds).

[0062] Example 4

[0063] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0064] In this embodiment, a work card authentication button is used instead of the lock trigger 5 and the release trigger 6. The work card authentication button is used to identify the public and improve operational security by avoiding unauthorized triggering through authentication (the response time is still kept within 10 seconds).

[0065] Example 5

[0066] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0067] 1. In this embodiment, a camera is used instead of the area sensor 7 at the target area 11. The camera is used to monitor dynamic targets and static obstacles 9, and the camera directly feeds the information back to the controller. The camera enhances detection accuracy and replaces millimeter-wave radar and photoelectric switches to monitor the status of the target area 11.

[0068] 2. In this embodiment, a face recognition sensor is used instead of the lock trigger 5 and the release trigger 6. The face recognition sensor is used to improve operational security and avoid unauthorized triggering through identity verification (the response time is still kept within 10 seconds).

[0069] Example 6

[0070] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1:

[0071] 1. In this embodiment, a camera is used instead of the area sensor 7 at the target area 11. The camera is used to monitor dynamic targets and static obstacles 9. The camera directly feeds the information back to the controller, replacing the pure controller logic verification.

[0072] 2. In this embodiment, a work card authentication button is used instead of the lock trigger 5 and the release trigger 6. The work card authentication button is used to identify the public and improve the security of operation. It avoids unauthorized triggering through identity verification (the response time is still kept within 10 seconds).

[0073] The above-described specific embodiments are preferred embodiments of the present invention and are not intended to limit the present invention. Any other changes or equivalent substitutions made without departing from the technical solution of the present invention are included within the protection scope of the present invention.

Claims

1. A dynamic blocking and unblocking system for AGV road areas, characterized in that: This system, applicable to target areas on sidewalks, main roads, and intersections of sidewalks and main roads, includes a locking trigger, a releasing trigger, an indicator light unit, a controller, an area sensor, an AGV navigation system, and an AGV. The locking and releasing triggers are respectively located outside the target area and at both ends of the sidewalk. The indicator light unit is located in the target area and at both ends of the sidewalk. The area sensor is located in the target area and scans it. The controller is connected to the locking trigger, the releasing trigger, the indicator light unit, the area sensor, and the AGV navigation system. The AGV navigation system is connected to the AGV. The controller receives signals from the locking or releasing triggers and issues locking or releasing commands to the AGV guidance system. The AGV navigation system plans paths and controls the AGV in real time based on the locking or releasing commands from the controller.

2. The AGV road area dynamic blocking and unblocking system according to claim 1, characterized in that: The area sensor includes a radar and a photoelectric switch. The radar is used to scan dynamic targets, and the photoelectric switch is used to detect static obstacles.

3. The AGV road area dynamic blocking and unblocking system according to claim 1, characterized in that: The area sensor is a camera.

4. The AGV road area dynamic blocking and unblocking system according to claim 1, characterized in that: Both the locking trigger and the unlocking trigger are facial recognition sensors.

5. The AGV road area dynamic blocking and unlocking system according to claim 1, characterized in that: The locking trigger and the unlocking trigger are work card authentication buttons.

6. The AGV road area dynamic blocking and unblocking system according to claim 1, characterized in that: The pedestrian walkway and the main road are also connected to auxiliary roads.

7. A control method for an AGV road area dynamic blocking and unlocking system, characterized in that: Includes the following steps: S1. The operator is at the entrance of the pedestrian walkway and triggers the locking trigger. The controller receives the blocking request signal from the locking trigger and issues an instruction to the area sensor. S2. The area sensor confirms whether there is a dynamic target in the target area of ​​the main road. If not, the indicator light unit is in a green light state and the operator can pass through the target area directly. Otherwise, proceed to step S5. S3. The operator is at the exit of the pedestrian walkway and triggers the release trigger. The controller receives the release request signal from the release trigger and issues an instruction to the area sensor. S4. The area sensor confirms whether there are dynamic targets and static obstacles in the target area of ​​the main road. If not, the indicator light unit is in a red light state and the AGV passes directly through the target area; otherwise, proceed to step S5. S5. After executing the exception handling mechanism to remove dynamic targets, return to step S2. After executing the exception handling mechanism to remove dynamic targets or static obstacles, return to step S4.

8. The control method for a dynamic blocking and unblocking system for AGV road areas according to claim 7, characterized in that: Step S2 specifically includes the following steps: S201. The area sensor scans the target area of ​​the main road to see if there is a dynamic target. If not, proceed to step S202; otherwise, proceed to step S5. S202, the controller sends a blocking command to the AGV navigation system. At the same time, the controller controls the green light of the indicator unit to be constantly on. The AGV navigation system sets the target area as a dynamic restricted area. The AGV guidance system excludes the coordinates of the dynamic restricted area and plans the path in real time. The AGV moves according to the real-time planned path.

9. The control method for an AGV road area dynamic blocking and unlocking system according to claim 7, characterized in that: Step S4 specifically includes the following steps: S401. The area sensor confirms whether there are dynamic targets and static obstacles in the target area of ​​the main road. If not, proceed to step S402; otherwise, proceed to step S5. S402, the controller sends a release command to the AGV navigation system and instructs the indicator light unit to be in a constant red light state. The AGV navigation system deletes the coordinates of the target area of ​​the restricted area and plans the shortest path. The AGV directly passes through the target area according to the shortest path.

10. The control method for an AGV road area dynamic blocking and unblocking system according to claim 7, characterized in that: The exception handling mechanism in step S5 includes the following steps: S501. When the target area is a dynamic restricted area and there is an AGV, the indicator light unit is in a flashing green light state, and the area sensor periodically scans the AGV until the AGV leaves the target area and then executes step S2. S502. When the target area is a safe area and there are dynamic targets or static obstacles, the indicator light unit is in a red flashing state, the area sensor detects and scans dynamic targets or static obstacles, and executes step S4 after there are no dynamic targets or static obstacles in the target area.

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