Safety control system, safety control method, and program

Abstract

To provide a safety control system capable of accurately determining whether an automatic conveying device passes according to a conveyance plan or an abnormality occurs in a work area where a safety fence cannot be provided.SOLUTION: A safety control system includes a plurality of laser sensors that are disposed at different heights in a vertical direction or at different positions in a horizontal direction at an entrance through which an automatic transport device enters a work area of a palletizer or exits from the work area and are capable of detecting an object present at the entrance, a detection data acquisition unit that acquires detection data of each of the laser sensors, a transport plan acquisition unit that acquires a transport plan of the automatic transport device, and a determination unit that determines whether the automatic transport device passes through the entrance according to the transport plan or whether an abnormality has occurred based on the detection data and the transport plan.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a safety control system, a safety control method, and a program. [Background technology]

[0002] Palletizers that automatically load and unload goods onto and from pallets are used in facilities such as warehouses and factories. If a person approaches the palletizer while it is operating, there is a possibility of an accident occurring due to contact. For example, Patent Document 1 describes a technology that ensures the safety of people (workers) who enter the palletizer's work area to load goods by stopping the palletizer's operation while a sensor inside a safety fence is detecting something. Furthermore, Patent Document 2 describes a technology that uses a distance measuring sensor that radially emits infrared rays to detect when a person enters a monitored area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7150490 [Patent Document 2] Patent No. 5000928 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, automated guided vehicles (AGVs) have been used to transport packages removed from warehouses into palletizer work areas or to transport pallets loaded by palletizers out of the work area. To prevent the movement of AGVs carrying tall cargo, it is difficult to enclose the palletizer work area with a safety fence, as in Patent Document 1. This could allow workers to pass through AGV entrances and exits that are not equipped with safety fences, potentially resulting in insufficient worker safety. Furthermore, as in Patent Document 2, when using a distance measuring sensor that emits infrared light at the emission point, it is difficult to detect tall objects near both ends of the measurement range. Furthermore, because the AGV's cargo creates a blind spot for the sensor, for example, if a worker enters the work area together with the AGV, it becomes difficult to detect the worker hidden by the cargo, reducing the detection accuracy of objects other than the AGV.

[0005] The object of the present disclosure is to provide a safety control system, a safety control method, and a program that can accurately determine whether an automatic transport device is passing through according to a transport plan or whether an abnormality has occurred in a work area where a safety fence cannot be installed. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a safety control system includes a plurality of laser sensors arranged at different vertical heights or different horizontal positions at entrances and exits through which an automatic conveying device enters or exits a palletizer work area, and capable of detecting objects present at the entrances and exits; a detection data acquisition unit that acquires detection data from each of the laser sensors; a transport plan acquisition unit that acquires a transport plan for the automatic conveying device; and a determination unit that determines, based on the detection data and the transport plan, whether the automatic conveying device is passing through the entrances and exits in accordance with the transport plan or whether an abnormality has occurred.

[0007] According to one aspect of the present disclosure, a safety control method includes the steps of acquiring detection data from a plurality of laser sensors that are arranged at different vertical heights or different horizontal positions at an entrance / exit through which an automatic conveying device enters or exits a palletizer work area, and that are capable of detecting objects present at the entrance / exit; acquiring a transport plan for the automatic conveying device; and determining, based on the detection data and the transport plan, whether the automatic conveying device is passing through the entrance / exit in accordance with the transport plan or whether an abnormality has occurred.

[0008] According to one aspect of the present disclosure, the program causes a safety control system to perform the following steps: acquiring detection data from multiple laser sensors that are arranged at different vertical heights or different horizontal positions at entrances and exits through which the automatic conveying device enters or exits the work area of ​​a palletizer and are capable of detecting objects present at the entrances and exits; acquiring a transport plan for the automatic conveying device; and determining, based on the detection data and the transport plan, whether the automatic conveying device is passing through the entrances and exits in accordance with the transport plan or whether an abnormality has occurred. [Effects of the Invention]

[0009] According to the above aspect, it is possible to accurately detect whether an object entering or leaving a work area where a safety fence cannot be installed is an automatic transport device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing the overall configuration of an automatic picking system according to a first embodiment. [Figure 2] 1 is a block diagram showing a functional configuration of a safety control system according to a first embodiment. [Figure 3] FIG. 2 is a diagram showing an example of a work area of ​​a palletizer according to the first embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of the arrangement of laser sensors according to the first embodiment. [Figure 5]4 is a first flowchart showing a processing example of the safety control system according to the first embodiment. [Figure 6] 6 is a second flowchart showing an example of processing of the safety control system according to the first embodiment. [Figure 7] 10 is a third flowchart illustrating an example of processing of the safety control system according to the first embodiment. [Figure 8] 10 is a fourth flowchart illustrating an example of processing of the safety control system according to the first embodiment. [Figure 9] FIG. 2 is a first diagram illustrating an example of a time series of detection data according to the first embodiment. [Figure 10] FIG. 2 is a second diagram showing an example of a time series of detection data according to the first embodiment. [Figure 11] FIG. 10 is a diagram showing an example of a work area of ​​a palletizer according to the second embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example of the arrangement of laser sensors according to the second embodiment. [Figure 13] 10 is a first flowchart showing an example of processing of a safety control system according to a second embodiment. [Figure 14] FIG. 6 is a diagram for explaining the function of a safety control system according to a second embodiment. [Figure 15] 10 is a second flowchart showing an example of processing of the safety control system according to the second embodiment. [Figure 16] 10 is a third flowchart illustrating an example of processing in the safety control system according to the second embodiment. [Figure 17] FIG. 10 is a diagram illustrating an example of a time series of detection data according to the second embodiment. [Figure 18] FIG. 10 is a diagram illustrating an example of the arrangement of laser sensors according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment The first embodiment will be described in detail below with reference to FIGS.

[0012] (Overall configuration of the automatic picking system) Fig. 1 is a schematic diagram showing the overall configuration of an automatic picking system according to the first embodiment. As shown in Fig. 1, the automatic picking system 100 includes a host system 1, a warehouse equipment control system 2, an AGV (automated guided vehicle) robot control system 3, a palletizer robot control system 4, an AGV (automated guided vehicle) 5, a palletizer 6, and a safety control system 10.

[0013] The upper system 1 performs operation management of the cargo and equipment in the warehouse. The upper system 1 creates a picking work plan including a transportation plan for the AGV 5 and transmits it to the warehouse equipment control system 2.

[0014] The warehouse equipment control system 2 outputs work instructions and the like to the AGV robot control system 3 and the palletizer robot control system 4 based on the picking work plan provided by the higher-level system 1. The warehouse equipment control system 2 also notifies the safety control system 10 of the transport plan for the AVG 5 and the work instructions to each of the robot control systems 3 and 4.

[0015] The AGV robot control system 3 outputs a control signal for controlling the AGV 5 in accordance with instructions from the warehouse equipment control system 2.

[0016] The palletizer robot control system 4 outputs a control signal for controlling the palletizer 6 in accordance with instructions from the warehouse equipment control system 2.

[0017] A plurality of AGVs 5 are operated simultaneously within a warehouse. The AGVs 5 transport pallets loaded with cargo in accordance with control signals from the AGV robot control system 3. The AGVs 5 may transport pallets using a platform.

[0018] The palletizer 6 is provided in a work area 60 in the warehouse. Only one palletizer 6 may be operated in the warehouse, or multiple palletizers 6 may be operated simultaneously. In accordance with control signals from the palletizer robot control system 4, the palletizer 6 picks up goods from a replenishment pallet brought into the work area 60 and loads them onto a shipping pallet.

[0019] The flow of transportation and picking will be briefly explained. For example, an unmanned forklift (not shown) removes a replenishment pallet from the storage area and places it on a platform. An AGV 5 enters under the platform, lifts it up from below, and transports it to the work area 60. The AGV 5 lowers the platform to a predetermined position in the work area. A palletizer 6 then picks items from the replenishment pallet on the platform that was brought in and stacks them on a shipping pallet on another platform. The AGV 5 then lifts the platform with the loaded shipping pallet on it and transports it to the shipping location. The AGV 5 also lifts the platform with the remaining items (replenishment pallets) on it and transports it to the storage area. When the AGV 5 lowers the platform to a predetermined position in the storage area, an unmanned forklift transports the replenishment pallet loaded on the platform into the storage area. Note that the AGV 5 may transport an empty platform (pallet) with no items on it.

[0020] The safety control system 10 monitors the entry of an object into the work area 60 of the palletizer 6 based on detection data from a plurality of laser sensors 11 provided in the work area 60 of the palletizer 6. If an object other than the AGV 5 enters the work area 60 or if a malfunction such as a breakdown occurs in the laser sensor 11, the safety control system 10 stops the operation of the palletizer 6 for safety reasons. Note that while FIG. 1 shows an example in which the safety control system 10 receives a transport plan from the warehouse equipment control system 2, in other embodiments, the safety control system 10 may receive the transport plan from the host system 1.

[0021] (Functional configuration of safety control system) 2 is a block diagram showing the functional configuration of the safety control system according to the first embodiment. As shown in FIG. 2, the safety control system 10 includes a processor 12, a memory 13, a storage 14, and a communication interface 15.

[0022] The processor 12 operates in accordance with a predetermined program to thereby fulfill the functions of a detection data acquisition unit 121, a transportation plan acquisition unit 122, a determination unit 123, and a stop processing unit .

[0023] The detection data acquisition unit 121 acquires the detection data from each of the plurality of laser sensors 11 .

[0024] The transport plan acquisition unit 122 acquires a transport plan for the AGV 5 entering and leaving the work area 60 of the palletizer 6. The transport plan includes information that can identify the transport timing of the AGV 5 and the height of the cargo to be loaded on the AGV 5 at each transport timing.

[0025] The determination unit 123 determines whether the AGV 5 is passing through the entrance / exit 63 of the work area 60 in accordance with the transportation plan, based on the detection data and the transportation plan, or whether an abnormality has occurred. Abnormalities include, for example, an object other than the AGV 5, such as a person, an AGV 5 traveling with a collapsed load (the load height does not match the transportation plan) passing through the entrance / exit 63, and a malfunction of the laser sensor 11.

[0026] The stop processing unit 124 stops the palletizer 6 when it is determined that an abnormality has occurred. Specifically, the stop processing unit 124 notifies the warehouse equipment control system 2 of the occurrence of the abnormality and instructs the palletizer 6 to stop. This stop instruction is transmitted from the warehouse equipment control system 2 to the palletizer robot control system 4. Upon receiving the stop instruction, the palletizer robot control system 4 outputs a control signal instructing the palletizer 6 to stop. Note that in another embodiment, the stop processing unit 124 may notify the warehouse equipment control system 2 of the occurrence of the abnormality and output an instruction to stop the palletizer 6 to the palletizer robot control system 4.

[0027] The memory 13 has a memory area necessary for the operation of the processor 12 .

[0028] The storage 14 is a so-called auxiliary storage device, such as a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 14 stores data that each part of the processor 12 acquires, generates, and refers to during processing.

[0029] The communication interface 15 is an interface for transmitting and receiving various data, control signals, and the like to and from each part of the automatic picking system 100 .

[0030] (Laser sensor installation example) Fig. 3 is a diagram showing an example of a work area of ​​a palletizer according to the first embodiment. Fig. 4 is a diagram showing an example of the arrangement of laser sensors according to the first embodiment. As shown in Fig. 3, a plurality of pillars 62 are installed with gaps between them at the outer edge of a work area 60 of the palletizer 6. These gaps serve as entrances 63 for the AGV 5 to enter and exit the work area 60. Note that while Fig. 3 shows an example in which eight entrances 63a to 63h are provided, the number of entrances 63 may be increased or decreased as desired.

[0031] Furthermore, multiple (n) laser sensors 11 are installed at different vertical heights on pillars 62 on both sides of entrance / exit 63. For simplicity, FIG. 3 shows an example in which laser sensor 11 is installed only at entrance / exit 63a, but in reality, laser sensors 11 are similarly installed at each of entrances 63b to 63h. Laser sensor 11 detects objects passing through entrance / exit 63 of work area 60 (entering or exiting work area 60). Laser sensor 11 is, for example, a transmission-type laser sensor consisting of a light-emitting unit 11a that emits a detection laser and a light-receiving unit 11b that receives the detection laser. Laser sensor 11 may also be a reflection-type laser sensor consisting of a light-emitting / receiving unit 11a that emits a detection laser and receives its reflected light, and a reflecting unit 11b that reflects the detection laser. Transmission-type laser sensor 11 detects the presence of an object at the installation height of laser sensor 11 because light-receiving unit 11b cannot receive the detection laser. Furthermore, the reflective laser sensor 11 detects the presence of an object at the installation height of the laser sensor 11 based on the time between emitting a detection laser and receiving the reflected light. Each laser sensor 11 transmits detection data that can identify the presence or absence of an object to the safety control system 10. Note that the laser sensor 11 may also be a distance measuring sensor that can output detection data that indicates the distance to the object.

[0032] FIG. 4 shows an example of the arrangement of the laser sensors 11 at each entrance / exit 63 (63a to 63h). Each laser sensor 11 is installed at a position corresponding to the height of each part of the AGV 5. In the example of FIG. 4, eight laser sensors 11_1 to 11_8 are installed at different heights. The laser sensor 11_1 is installed at a height at which it can detect the tires (or body) of the AGV 5. The laser sensor 11_2 is installed at a height at which it can detect the platform lifted up by the AGV 5. The laser sensor 11_3 is installed at a height at which it can detect the pallet placed on the platform. The laser sensor 11_4 is installed at a height at which it can detect the first layer (the bottom layer) of packages stacked on the pallet. Similarly, the laser sensors 11_5 to 11_8 are installed at heights at which it can detect the second to fifth layers of packages, respectively. The number of laser sensors 11 may be changed arbitrarily depending on the height of the packages transported by the AGV 5.

[0033] (Safety control system processing example 1) 5 is a first flowchart showing a processing example of the safety control system according to the first embodiment. Processing example 1 of the safety control system 10 will be described with reference to FIG.

[0034] First, the transfer plan acquisition unit 122 acquires a transfer plan from the warehouse equipment control system 2 (step S101). The transfer plan acquisition unit 122 may acquire a transfer plan for one day all at once, for example, before the start of operation each day. Also, for example, the upper system 1 may monitor the status of the AGV 5 (position, presence or absence of cargo) and the status of goods delivered to the warehouse (delays, etc.) through the warehouse equipment control system 2 and update the transfer plan. When the transfer plan is updated, the warehouse equipment control system 2 transmits the updated transfer plan to the safety control system 10. In this way, the transfer plan acquisition unit 122 may acquire a new transfer plan from the warehouse equipment control system 2 every time the transfer plan is updated.

[0035] The detection data acquisition unit 121 acquires detection data from each of the plurality of laser sensors 11 (step S102).

[0036] The determination unit 123 determines whether an object has been detected at the entrance / exit 63 of the work area 60 based on the detection data (step S103). If an object is not detected (all detection data = detection OFF) (step S103; NO), the process returns to step S102. On the other hand, if at least one laser sensor 11 has detected an object (detection data = detection ON) (step S103; YES), the determination unit 123 determines whether the timing coincides with the transport timing of the AGV 5 identified from the transport plan (step S104).

[0037] If the detection timing of the object matches the transport timing of the AGV 5 identified from the transport plan (step S104; YES), the determination unit 123 determines that the detected object is an AGV 5 and continues the operation of the palletizer 6 (step S115). The transport plan includes information such as the origin and destination of each AGV 5, the number and type of luggage to be transported, the scheduled arrival time at the origin, and the scheduled arrival time at the destination. From this information, the determination unit 123 determines the transport timing for each AGV 5 to transport luggage to or from the work area 60. Note that the determination unit 123 determines that the detection timing and the transport timing match, for example, if the detection timing is within the allowable time before or after the transport timing. In this way, a slight difference between the detection timing and the transport timing may be tolerated.

[0038] On the other hand, if the detection timing of the object does not coincide with the transport timing of the AGV 5 (step S104; NO), that is, if the AGV 5 is not scheduled to transport a package to or from the work area 60 at that time, the determination unit 123 determines that the detected object is a foreign object other than the AGV 5. In this case, the stop processing unit 124 outputs an instruction to stop the palletizer 6 to the warehouse equipment control system 2 (or the palletizer robot control system 4) to urgently stop the operation of the palletizer 6 (step S116).

[0039] 5 while the automatic picking system 100 is in operation, the safety control system 10 repeatedly performs the series of processes shown in Fig. 5 to monitor whether there are any abnormalities at each entrance / exit 63. As a result, the safety control system 10 can detect that a foreign object other than the planned AGV 5 has entered the work area 60 and stop the palletizer 6 for safety reasons.

[0040] (Safety control system processing example 2) Fig. 6 is a second flowchart showing a processing example of the safety control system according to the first embodiment. Processing example 2 of the safety control system 10 will be described with reference to Fig. 6. Fig. 6 shows the flow of processing after the transport plan acquisition unit 122 acquires a transport plan (step S101 in Fig. 5). Note that processing example 2 may be executed instead of the above-described processing example 1, or may be executed in parallel with processing example 1.

[0041] The detection data acquisition unit 121 acquires detection data from each laser sensor 11 (step S201). Furthermore, the determination unit 123 determines whether an object has been detected at the entrance / exit 63 of the work area 60 based on the detection data (step S202). These processes are the same as steps S102 to S103 in FIG. 5. If an object is not detected (step S202; NO), the process returns to step S201. If an object is detected (step S202; YES), the determination unit 123 determines whether the detected object is an AGV 5 that will transport the package according to the transport plan.

[0042] Specifically, the determination unit 123 first determines whether the lowest laser sensor 11_1 has detected an object (detection data=detection ON) (step S203). If the other laser sensors 11 have detected an object but the laser sensor 11_1 has not (step S203; NO), there is no object at the position where the tires of the AGV 5 are expected to be, which means that there is a possibility that a foreign object other than the AGV 5 (such as a human) has entered or that the laser sensor 11_1 is malfunctioning. Therefore, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S230). The processing of step S230 is the same as the processing of step S106 in FIG. 5.

[0043] Furthermore, if the laser sensor 11_1 detects an object (step S203; YES), the determination unit 123 determines whether the laser sensor 11_2 above has detected an object (step S204). If the laser sensor 11_2 has not detected an object (step S204; NO), the determination unit 123 compares the installation height of the laser sensor 11_2 with the height of the load on the AGV 5 identified from the transportation plan (step S211).

[0044] Specifically, the determination unit 123 identifies an AGV 5 whose object detection timing and transport timing match (within the allowable time) from the transport plan, and acquires information that can identify the height of the cargo carried by this AGV 5. For example, the determination unit 123 can determine whether the cargo carried by the AGV 5 is "none (AGV 5 traveling alone)," "only a platform," "only a platform and a pallet," or "x layers of cargo" using information on the cargo to be transported and the number of cargoes included in the transport plan. The number of layers of cargo can be identified, for example, by further using the size of each cargo item recorded in advance in the storage 14. The sizes (height, width, length, etc.) of the AGV 5, platform, and pallet are also recorded in advance in the storage 14. When the AGV 5 travels without any cargo, the installation height of the laser sensor 11_2 is greater than the cargo height of the AGV 5 (the height of the AGV 5 itself). In such a case, the installation height of the laser sensor 11_2 is greater than the cargo height (step S211; YES), so the judgment unit 123 judges that the detected object is an AGV 5 transporting cargo according to the transportation plan, and allows the palletizer 6 to continue operation (step S210).

[0045] On the other hand, if the installation height of the laser sensor 11_2 is equal to or less than the load height (step S211; NO), the determination unit 123 determines that the detected object is not an AGV 5 that is transporting according to the transport plan (it is a foreign object), or that the laser sensor 11_2 is malfunctioning. This foreign object may be, for example, an object other than the AGV 5, such as a human, or an abnormal AGV 5. An abnormal AGV 5 is, for example, an AGV 5 whose load height does not match the load height in the transport plan due to the influence of a load collapse or the like. In this case, the stop processing unit 124 makes an emergency stop of the operation of the palletizer 6 for safety reasons (step S230).

[0046] Next, if an object is detected by both of the laser sensors 11_1 and 11_2 (step S204; YES), the determination unit 123 determines whether the upper laser sensor 11_3 has detected an object (step S205). If the laser sensor 11_3 has not detected an object (step S205; NO), the determination unit 123 compares the installation height of the laser sensor 11_3 with the load height of the AGV 5 identified from the transportation plan (step S212). The processing of step S212 is the same as step S211. When the AGV 5 travels with only the platform loaded, the installation height of the laser sensor 11_3 is greater than the load height of the AGV 5 (height of the AGV 5 + the platform). In such a case, since the installation height of the laser sensor 11_3 is greater than the load height (step S212; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transport plan, and allows the palletizer 6 to continue operation (step S210). On the other hand, if the installation height of the laser sensor 11_3 is equal to or less than the load height (step S212; NO), the determination unit 123 determines that the detected object is a foreign object or a malfunction of the laser sensor 11_3, as in step S211. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S230).

[0047] Furthermore, when an object is detected by each of the laser sensors 11_1 to 11_3 (step S205; YES), the determination unit 123 determines whether the upper laser sensor 11_4 has detected an object (step S206). When the laser sensor 11_4 has not detected an object (step S206; NO), the determination unit 123 compares the installation height of the laser sensor 11_4 with the load height of the AGV 5 identified from the transportation plan (step S213). The processing of step S213 is the same as step S211. When the AGV 5 travels with only a platform and a pallet loaded, the installation height of the laser sensor 11_4 is greater than the load height of the AGV 5 (height of the AGV 5 + platform + pallet). In such a case, since the installation height of the laser sensor 11_4 is greater than the load height (step S213; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transport plan, and allows the palletizer 6 to continue operation (step S210). On the other hand, if the installation height of the laser sensor 11_4 is equal to or less than the load height (step S213; NO), the determination unit 123 determines that the detected object is a foreign object or a malfunction of the laser sensor 11_4, as in step S211. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S230).

[0048] Similarly, when an object is detected by each of the laser sensors 11_1 to 11_4 (step S206; YES), the determination unit 123 determines whether the upper laser sensor 11_5 has detected an object (step S207). When the laser sensor 11_5 has not detected an object (step S207; NO), the determination unit 123 compares the installation height of the laser sensor 11_5 with the load height of the AGV 5 identified from the transportation plan (step S214). The processing of step S214 is the same as step S211. When the AGV 5 travels with only one layer of loads loaded, the installation height of the laser sensor 11_5 is greater than the load height of the AGV 5 (height of the AGV 5 + platform + pallet + one layer of loads). In such a case, since the installation height of the laser sensor 11_5 is greater than the load height (step S214; YES), the determination unit 123 determines that the detected object is an AGV 5 that transports the load according to the transport plan, and allows the palletizer 6 to continue operation (step S210). On the other hand, if the installation height of the laser sensor 11_5 is less than or equal to the load height (step S214; NO), the determination unit 123 determines that the detected object is a foreign object or a malfunction of the laser sensor 11_5, as in step S211. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S230). The determination unit 123 also performs the same processes as in steps S207 and S214 for the subsequent laser sensors 11_6 to 11_n (n=8 in the example of FIG. 4) to determine whether the detected object is an AGV 5, a foreign object, or a sensor malfunction.

[0049] Furthermore, if all the laser sensors 11_1 to 11_n detect an object, the determining unit 123 determines that the detected object is the AGV 5 that transports the package according to the transport plan, and allows the palletizer 6 to continue its operation (step S210).

[0050] 6 while the automatic picking system 100 is in operation, the safety control system 10 repeatedly performs the series of processes shown in Fig. 6 to monitor for any abnormalities at each entrance / exit 63. As a result, the safety control system 10 can detect that a foreign object other than the planned AGV 5 has entered the work area 60 or that a malfunction has occurred in the laser sensor 11, and can stop the palletizer 6 for safety reasons.

[0051] (Safety control system processing example 3) Fig. 7 is a third flowchart showing a processing example of the safety control system according to the first embodiment. Processing example 4 of the safety control system 10 will be described with reference to Fig. 7. Fig. 7 shows the flow of processing after the transport plan acquisition unit 122 acquires a transport plan (step S101 in Fig. 5). Note that this processing example 3 is executed instead of the above-described processing example 2. Note that in this processing example 3, the laser sensor 11 is a distance measurement sensor that outputs detection data indicating the distance to a detected object.

[0052] The detection data acquisition unit 121 acquires detection data from each laser sensor 11 (step S301). Furthermore, the determination unit 123 determines whether an object has been detected at the entrance / exit 63 of the work area 60 based on the detection data (step S302). The storage 14 pre-records the measured distances (reference distances) of the laser sensors when no object is present. If the measured distances included in all the detection data match the reference distance, the determination unit 123 determines that no object has been detected (step S302; NO) and returns to step S301. Taking into account measurement error, the determination unit 123 determines that the measured distances match the reference distance if they are within a predetermined value. On the other hand, if the measured distance is shorter than the reference distance by a predetermined value or more in the detection data of at least one laser sensor 11, the determination unit 123 determines that an object has been detected by this laser sensor 11 (step S302; YES). In this case, the determination unit 123 determines whether the detected object is an AGV 5 that is transporting the package according to the transport plan, or whether the detected object is a foreign object or a malfunction of the laser sensor 11.

[0053] Specifically, the determination unit 123 first determines whether the lowest laser sensor 11_1 has detected an object (detection data=detection ON) (step S303). The process of step S303 corresponds to step S203 in FIG. 6. That is, when the laser sensor 11_1 has not detected an object even though the other laser sensors 11 have detected an object (step S303; NO), the determination unit 123 determines that there is a possibility that a foreign object such as a human has entered the palletizer 6 or that the laser sensor 11_1 is malfunctioning. Therefore, the stop processing unit 124 makes an emergency stop of the operation of the palletizer 6 for safety reasons (step S330). The process of step S330 is the same as the process of step S106 in FIG. 5.

[0054] Furthermore, if the laser sensor 11_1 detects an object (step S303; YES), the determination unit 123 determines whether the laser sensor 11_2, which is further above, has detected an object (step S304). If the laser sensor 11_2 has not detected an object (step S304; NO), the determination unit 123 compares the installation height of the laser sensor 11_2 with the load height of the AGV 5 identified from the transportation plan (step S311). The comparison process of step S311 is the same as the comparison process of step S311 in FIG. 6. If the installation height of the laser sensor 11_2 is greater than the load height (step S311; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transportation plan, and continues the operation of the palletizer 6 (step S310). On the other hand, if the installation height of the laser sensor 11_2 is equal to or less than the cargo height (step S311; NO), the judgment unit 123 determines whether the detection width of the object estimated from the measurement distance of the laser sensor 11_1 below matches the cargo width of the cargo identified from the transportation plan (step S321).

[0055] Specifically, the determination unit 123 identifies an AGV 5 whose object detection timing and transport timing match (within the allowable time) from the transportation plan, and acquires information that can identify the cargo width of the cargo carried by this AGV 5. For example, the determination unit 123 can identify the cargo width for each layer of the AGV 5 based on information about the cargo and the number of cargoes to be transported, which is included in the transportation plan, and the size of each cargo item pre-recorded in the storage 14. The sizes (height, width, length, etc.) of the AGV 5, platform, and pallet are also pre-recorded in the storage 14. The determination unit 123 estimates the detection width of the object from the measured distance to the object by the laser sensor 11, assuming that the object will pass through the center of the entrance / exit 63. For example, if the width of the entrance / exit 63 is a, the measured distance is b, and the detection width is c, the determination unit 123 estimates that c = a - 2b. If the difference between the detection width and the cargo width is within a predetermined allowable error, the determination unit 123 determines that the detection width matches the cargo width. In step S321, if the detection width based on the measurement distance of the laser sensor 11_1 matches the cargo width (width of the AGV 5) (step S321; YES), the determination unit 123 determines that the laser sensor 11_1 correctly detected the AGV 5 and that the laser sensor 11_2 made an erroneous detection. In this case, the determination unit 123 determines that the detected object is the AGV 5 that transports cargo according to the transport plan, and allows the palletizer 6 to continue operation (step S310).

[0056] On the other hand, if the detection width based on the measurement distance of the laser sensor 11_1 does not match the load width (the width of the AGV 5) (step S321; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_2 is defective. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S330).

[0057] Next, when an object is detected by both of the laser sensors 11_1 and 11_2 (step S304; YES), the determination unit 123 determines whether the upper laser sensor 11_3 has detected an object (step S305). When the laser sensor 11_3 has not detected an object (step S305; NO), the determination unit 123 compares the installation height of the laser sensor 11_3 with the load height of the AGV 5 identified from the transportation plan (step S312). The process of step S312 is the same as the process of step S311. When the installation height of the laser sensor 11_3 is greater than the load height (step S312; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transportation plan, and continues the operation of the palletizer 6 (step S310). On the other hand, if the installation height of the laser sensor 11_3 is equal to or less than the load height (step S312; NO), the determination unit 123 determines whether the detection width based on the measurement distance of the laser sensor 11_2, which is one level lower, matches the load width (width of the platform) of the AGV 5 identified from the transportation plan (step S322). The processing of step S322 is the same as the processing of step S321. If the detection width based on the measurement distance of the laser sensor 11_2 matches the load width (width of the platform) (step S322; YES), the determination unit 123 determines that the laser sensor 11_2 correctly detected the platform placed on the AGV 5 and that the laser sensor 11_3 made an erroneous detection. In this case, the determination unit 123 determines that the detected object is the AGV 5 that transports the package according to the transportation plan, and allows the palletizer 6 to continue operation (step S310). On the other hand, if the detection width based on the measurement distance of the laser sensor 11_2 does not match the load width (the width of the platform) (step S322; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_3 is defective. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S330).

[0058] Furthermore, when an object is detected by each of the laser sensors 11_1 to 11_3 (step S305; YES), the determination unit 123 determines whether the upper laser sensor 11_4 has detected an object (step S306). When the laser sensor 11_4 has not detected an object (step S306; NO), the determination unit 123 compares the installation height of the laser sensor 11_4 with the load height of the AGV 5 identified from the transportation plan (step S313). The processing of step S313 is the same as step S311. When the installation height of the laser sensor 11_4 is greater than the load height (step S313; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transportation plan, and allows the palletizer 6 to continue operation (step S310). On the other hand, if the installation height of the laser sensor 11_4 is equal to or less than the load height (step S313; NO), the determination unit 123 determines whether the detection width based on the measurement distance of the laser sensor 11_3, which is one level lower, matches the load width (the width of the pallet) of the AGV 5 specified from the transportation plan (step S323). The processing of step S323 is the same as the processing of step S321. If the detection width based on the measurement distance of the laser sensor 11_3 matches the load width (the width of the pallet) (step S323; YES), the determination unit 123 determines that the laser sensor 11_3 correctly detected the pallet placed on the AGV 5 and that the laser sensor 11_4 made an erroneous detection. In this case, the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transportation plan, and allows the palletizer 6 to continue operation (step S310). On the other hand, if the detection width based on the measurement distance of the laser sensor 11_3 does not match the product width (the width of the pallet) (step S323; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_4 is defective. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S330).

[0059] Similarly, when an object is detected by each of the laser sensors 11_1 to 11_4 (step S306; YES), the determination unit 123 determines whether the upper laser sensor 11_5 has detected an object (step S307). When the laser sensor 11_5 has not detected an object (step S307; NO), the determination unit 123 compares the installation height of the laser sensor 11_5 with the load height of the AGV 5 identified from the transportation plan (step S314). The processing of step S314 is the same as step S311. When the installation height of the laser sensor 11_5 is greater than the load height (step S314; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports the load according to the transportation plan, and continues the operation of the palletizer 6 (step S310). On the other hand, if the installation height of the laser sensor 11_5 is equal to or less than the cargo height (step S314; NO), the determination unit 123 determines whether the detection width based on the measurement distance of the laser sensor 11_4, which is one level lower, matches the cargo width of the AGV 5 identified from the transportation plan (step S324). The processing of step S324 is the same as the processing of step S321. If the detection width based on the measurement distance of the laser sensor 11_4 matches the cargo width (the width of the cargo in the first layer) (step S324; YES), the determination unit 123 determines that the laser sensor 11_4 correctly detected the cargo in the first layer placed on the AGV 5 and that the laser sensor 11_5 made an erroneous detection. In this case, the determination unit 123 determines that the detected object is the AGV 5 that transports the cargo according to the transportation plan, and allows the palletizer 6 to continue operation (step S310). On the other hand, if the detection width based on the measurement distance of the laser sensor 11_4 does not match the package width (package width of the first layer) (step S324; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_5 is malfunctioning. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S330). The determination unit 123 performs the same processes as in steps S307, S314, and S324 for the subsequent laser sensors 11_6 to 11_n (n=8 in the example of FIG. 4) to determine whether the detected object is the AGV 5, a foreign object, or a sensor malfunction.

[0060] Furthermore, if all the laser sensors 11_1 to 11_n detect an object, the determining unit 123 determines that the detected object is the AGV 5 that transports the package according to the transport plan, and allows the palletizer 6 to continue its operation (step S310).

[0061] 7 while the automatic picking system 100 is in operation, the safety control system 10 repeatedly performs the series of processes shown in Fig. 7 to monitor for any abnormalities at each entrance / exit 63. As a result, the safety control system 10 can detect that a foreign object other than the planned AGV 5 has entered the work area 60 or that a malfunction has occurred in the laser sensor 11, and can stop the palletizer 6 for safety reasons.

[0062] (Safety control system processing example 4) Fig. 8 is a fourth flowchart showing a processing example of the safety control system according to the first embodiment. Processing example 4 of the safety control system 10 will be described with reference to Fig. 8. Note that processing example 4 may be executed instead of processing examples 1 to 3 described above, or may be executed in parallel with processing examples 1 to 3.

[0063] First, the detection data acquisition unit 121 acquires a time series of detection data (step S401). This time series of detection data consists of multiple consecutive detection data acquired when an object passes through the entrance / exit 63 of the work area 60. For example, the detection data acquisition unit 121 acquires a time series of detection data for a certain period of time after the laser sensor 11 detects the object. The certain period of time is set based on the time required for the AGV 5 to pass through the entrance / exit 63, for example, from the size (maximum length in the traveling direction) and traveling speed of the AGV 5, etc.

[0064] Next, the determination unit 123 determines whether the detection pattern of the laser sensor 11 when an object specified from the time series of the detection data passes matches the expected detection pattern when the AGV 5 passes (step S402). For example, in this embodiment, the determination unit 123 compares the detection pattern obtained from the time series of the detection data of the laser sensor 11_1 at the bottom with the expected detection pattern.

[0065] FIG. 9 is a first diagram showing an example of a time series of detection data according to the first embodiment. FIG. 9 shows an example of an assumed detection pattern P1a of the laser sensor 11_1 when the AGV 5 passes through the entrance / exit 63, and, for comparison, an assumed detection pattern P2a of the laser sensor 11_1 when a human passes through the entrance / exit 63. The horizontal axis of FIG. 9 represents time, and the vertical axis represents whether an object is detected (detection data ON / OFF). The assumed detection pattern P1a of the AGV 5 may be a pattern calculated from the length (size in the traveling direction) and traveling speed of the AGV 5, or may be a pattern created by collecting detection data of the laser sensor 11_1 in advance. The same applies to the assumed detection pattern P2a of a human. In the case of the AGV 5, the detection ON continues for a certain period of time according to the length and traveling speed of the AGV 5, resulting in a detection pattern P1a. On the other hand, when a person passes through the doorway 63, for example, they alternate between moving their right and left feet, so the period is divided into two short detection ON periods: one period when one foot is detected and one period when the other foot is detected, as shown in the assumed detection pattern P2a illustrated in Figure 9. As such, the AGV 5 and a person have different detection ON / OFF switching timings and the length of the detection ON period, so the assumed detection pattern P1a of the AGV 5 and the assumed detection pattern P2a of a person are significantly different. Therefore, by comparing the detection patterns, it is possible to distinguish between the AGV 5 and a person.

[0066] Based on this, in step S402, the determination unit 123 compares the detection pattern obtained from the time series of the detection data of the laser sensor 11_1 with the expected detection pattern P1a of the AGV 5 recorded in advance in the storage 14. If the detection pattern of the laser sensor 11_1 matches the expected detection pattern P1a of the AGV 5 (step S402; YES), the determination unit 123 determines that the detected object is the AGV 5 that transports packages according to the transport plan, and allows the palletizer 6 to continue operation (step S403).

[0067] On the other hand, if the detection pattern of the laser sensor 11_1 does not match the expected detection pattern P1a of the AGV 5 (step S402; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_1 is malfunctioning. The determination unit 123 may compare the detection pattern of the laser sensor 11_1 with the expected detection pattern P2a of a human, and if they match, determine that the detected object is a foreign object (human) rather than the AGV 5. In this case, the stop processing unit 124 makes an emergency stop of the operation of the palletizer 6 for safety reasons (step S404). The processing of step S404 is the same as the processing of step S106 in FIG. 5.

[0068] Furthermore, if the laser sensor 11 is a distance measurement sensor capable of measuring the distance to an object, the process of step S402 in FIG. 8 may be changed based on the change pattern of the detection width in FIG.

[0069] FIG. 10 is a second diagram illustrating an example of a time series of detection data according to the first embodiment. FIG. 10 illustrates an example of an expected change pattern P1b of the detection width of the AGV 5 and, for comparison, an expected change pattern P2b of the detection width of a human. The horizontal axis of FIG. 10 represents time, and the vertical axis represents the detection width of the object. The expected change pattern P1b of the AGV 5 may be a pattern calculated from the width and traveling speed of the AGV 5, or may be a pattern created by collecting detection data from the laser sensor 11_1 in advance. The same is true for the expected change pattern P2b of the human. Since the AGV 5 has a substantially constant width, the expected change pattern P1b results in a roughly constant detection width. On the other hand, a human passes through the entrance / exit 63, for example, by alternately moving their right and left feet. Therefore, two change patterns of the detection width appear, one when one foot is detected and the other when the other foot is detected, as illustrated in the expected change pattern P2b illustrated in FIG. 10. As described above, the expected change pattern P1b of the AGV 5 and the expected change pattern P2b of a human are significantly different due to the difference in shape between the AGV 5 and the human. Therefore, by comparing the change patterns of the detection width, it is possible to distinguish between the AGV 5 and the human.

[0070] Based on this, in step S402, the determination unit 123 compares the change pattern of the detection width obtained from the time series of the detection data of the laser sensor 11_1 with the expected change pattern P1b of the detection width of the AGV 5 recorded in advance in the storage 14. If the change pattern of the detection width of the laser sensor 11_1 matches the expected change pattern P1b of the AGV 5 (step S402; YES), the determination unit 123 determines that the detected object is the AGV 5 transporting packages according to the transport plan, and continues the operation of the palletizer 6 (step S403). On the other hand, if the change pattern of the detection width of the laser sensor 11_1 does not match the expected change pattern P1b of the AGV 5 (step S402; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11_1 is malfunctioning. In this case, the stop processing unit 124 urgently stops the operation of the palletizer 6 for safety reasons (step S404).

[0071] 8 while the automatic picking system 100 is in operation, the safety control system 10 repeatedly performs the series of processes shown in Fig. 8 to monitor whether there are any abnormalities at each entrance / exit 63. As a result, the safety control system 10 can detect that a foreign object other than the planned AGV 5 has entered the work area 60 and stop the palletizer 6 for safety reasons.

[0072] (Action and effect) As described above, the safety control system 10 according to this embodiment includes a plurality of laser sensors 11 that are arranged at different heights vertically at the entrance / exit 63 of the work area 60 of the palletizer 6 and that can detect objects present at the entrance / exit 63, a detection data acquisition unit 121 that acquires detection data from each laser sensor 11, a transport plan acquisition unit 122 that acquires a transport plan for the AGV 5 entering and exiting the work area 60, and a determination unit 123 that determines, based on the detection data and the transport plan, whether the AGV 5 is passing through the entrance / exit 63 of the work area 60 in accordance with the transport plan or whether an abnormality has occurred.

[0073] By doing this, the safety control system 10 can accurately determine whether the AGV 5 is passing through according to the transport plan or whether an abnormality has occurred, based on the detection data of the laser sensor 11, which is installed at the entrance / exit 63 of the work area 60 where a safety fence cannot be installed so as not to obstruct the movement of the AGV 5.

[0074] In addition, the judgment unit 123 judges that an abnormality has occurred if the timing at which the laser sensor 11 outputs detection data indicating that an object has been detected does not match the transport timing of the AGV 5 identified from the transport plan.

[0075] In this way, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transportation plan or whether a foreign object different from the transportation plan is passing.

[0076] The laser sensors 11 are arranged at different heights in the vertical direction. The determination unit 123 determines that an abnormality has occurred when a first laser sensor, which is one of the laser sensors 11, outputs detection data indicating that it has detected an object, and a second laser sensor arranged above the first laser sensor outputs detection data indicating that it has not detected an object, and the installation height of the second laser sensor is equal to or lower than the height of the package identified from the transportation plan.

[0077] In this way, the safety control system 10 can distinguish whether an AGV 5 carrying cargo according to the transport plan is passing through, or whether a foreign object (such as a human or an AGV 5 with its cargo falling) that is different from the transport plan is passing through, or whether a malfunction has occurred in the laser sensor 11.

[0078] In addition, the judgment unit 123 judges that the AGV 5 is passing through the entrance / exit 63 in accordance with the conveyance plan when a first laser sensor, which is one of the multiple laser sensors 11, outputs detection data indicating that it has detected an object, and when a second laser sensor positioned above the first laser sensor outputs detection data indicating that it has not detected an object, and when the installation height of the second laser sensor is equal to or less than the cargo height of the cargo identified from the conveyance plan, and when the detection width of the object estimated from the measured distance to the object by the first laser sensor matches the cargo width of the cargo identified from the conveyance plan.

[0079] By doing this, when the laser sensor 11 is a ranging sensor, even if a false detection occurs in the second laser sensor, the safety control system 10 can correctly determine that the AGV 5 is passing according to the transportation plan from the detection data of the first laser sensor.

[0080] In addition, the judgment unit 123 judges that an abnormality has occurred if the detection pattern when an object passes through the entrance / exit 63 identified from the time series of the detection data does not match the pre-set expected detection pattern P1a of the AGV 5.

[0081] By doing this, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account that the detection patterns differ between the AGV 5 and foreign objects (humans).

[0082] In addition, the judgment unit 123 judges that an abnormality has occurred if the change pattern of the detection width of an object passing through the entrance / exit 63 estimated from the time series of the detection data does not match the expected change pattern of the detection width of the AGV 5 that has been set in advance.

[0083] By doing this, when the laser sensor 11 is a distance measurement sensor, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account the different shapes of the AGV 5 and the foreign object (human).

[0084] The safety control system 10 further includes a stop processing unit 124 that stops the palletizer 6 when it is determined that an abnormality has occurred.

[0085] In this way, if any abnormality occurs (such as a worker entering the work area 60, a load shift on the AGV 5, or a malfunction of the laser sensor 11), the safety control system 10 can stop the operation of the palletizer 6 to ensure the safety of the worker and prevent damage caused by contact between the AGV 5 and the palletizer 6.

[0086] <Second embodiment> Next, the second embodiment will be described in detail with reference to Figures 11 to 17. Components common to the above-described embodiment will be given the same reference numerals and detailed description will be omitted.

[0087] (Laser sensor installation example) Fig. 11 is a diagram showing an example of a work area of ​​a palletizer according to the second embodiment. Fig. 12 is a diagram showing an example of the arrangement of laser sensors according to the second embodiment. As shown in Fig. 11, a support part 64 for attaching the laser sensor 11 is provided above the work area 60 of the palletizer 6.

[0088] Entrances 63 for the AGVs 5 to enter and exit the work area 60 are provided at the outer edge of the work area 60. While Fig. 11 shows an example in which twelve entrances 63a to 63l are provided, the number of entrances 63 may be increased or decreased as desired.

[0089] Each laser sensor 11 is attached to a support 64 so as to face vertically downward. Each laser sensor 11 is attached at a different horizontal position along the outer edge of the support part 64 so that it can project a detection laser at a different position on the outer edge of the work area 60. For simplicity, FIG. 11 shows an example in which the laser sensor 11 is provided only at the entrance / exit 63a, but in reality, a laser sensor 11 is similarly provided at each of the entrances 63b to 63l. The laser sensor 11 detects an object passing through the entrance / exit 63 of the work area 60 (entering or exiting the work area 60). The laser sensor 11 of this embodiment is a distance measuring sensor that can output detection data indicating the distance to an object.

[0090] FIG. 12 shows an example of the arrangement of laser sensors 11 at entrances 63a to 63c provided on one side of the work area 60. Each laser sensor 11 is installed at a different position in the horizontal direction. In the example of FIG. 12, seven laser sensors 11_1a to 11_a7, 11_b1 to 11_b7, and 11_c1 to 11_c7 are provided at each of the entrances 63a, 63b, and 63c. Note that FIG. 12 is just an example, and the number of laser sensors 11 and their installation intervals can be changed as desired. For example, the number of laser sensors 11 and their installation intervals are set based on the size of the short and long sides of the pallet, the size of the short and long sides of the expected cargo, etc.

[0091] (Safety control system processing example 5) FIG. 13 is a first flowchart showing a processing example of the safety control system according to the second embodiment. Processing example 5 of the safety control system 10 will be described with reference to FIG. 13. The safety control system 10 of this embodiment may execute processing example 1 of FIG. 5 of the first embodiment. The content of processing example 1 is the same as that of the first embodiment, so description thereof will be omitted. Furthermore, the safety control system 10 executes processing example 5 shown in FIG. 13 instead of processing example 1 or in parallel with processing example 1. FIG. 13 shows the flow of processing after the transport plan acquisition unit 122 acquires a transport plan (step S101 in FIG. 5).

[0092] The detection data acquisition unit 121 acquires detection data from each laser sensor 11 (step S501). The determination unit 123 determines whether an object has been detected at the entrance / exit 63 of the work area 60 based on the detection data (step S502). Taking the entrance / exit 63a as an example, the determination unit 123 determines whether an object has been detected at the entrance / exit 63a based on the detection data of the laser sensors 11_a1 to 11_a7 (step S502). The storage 14 pre-records the measured distances (reference distances) of the laser sensors when no object is present. If the measured distances included in all the detection data match the reference distances, the determination unit 123 determines that no object has been detected (step S502; NO) and returns to step S501. Note that, taking into account measurement errors, if the measured distances are within a predetermined value from the reference distance, the determination unit 123 determines that there is a match. On the other hand, if the measured distance in the detection data of at least one laser sensor 11 is shorter than the reference distance by a predetermined value or more, the determination unit 123 determines that an object has been detected by this laser sensor 11 (step S502; YES). In this case, the determination unit 123 determines whether the detected object is an AGV 5 that is transporting luggage according to the transport plan, or a foreign object or a malfunction of the laser sensor 11.

[0093] The determination unit 123 measures the height of the object from the detection data of each of the laser sensors 11_a1 to 11_a7 (steps S503a to S503g). The height of the object is calculated by subtracting the measured distance from the installation height of the laser sensor 11.

[0094] Next, the determination unit 123 compares the horizontal height of each part of the object based on the detection data of each of the laser sensors 11_a1 to 11_a7 with the package height of the package identified from the transportation plan (steps S504a to S504g).

[0095] Specifically, the determination unit 123 identifies an AGV 5 whose object detection timing and transportation timing match (within an allowable time) from the transportation plan, and acquires information that can identify the cargo height of the cargo carried by this AGV 5. For example, the determination unit 123 calculates the cargo height based on information on the cargo to be transported and the number of cargoes included in the transportation plan, the size (height) of each cargo item recorded in advance in the storage 14, and the height of the AGV 5 according to whether or not a rack or pallet is mounted, recorded in advance in the storage 14. As described above, the installation intervals of the laser sensors 11_a1 to 11_a7 are set based on the size of the cargo and pallet to be transported by the AGV 5. Therefore, assuming that the AGV 5 passes through the center of the entrance / exit 63a, as shown in FIG. 12, the laser sensors 11_a1 and 11_a7 at both ends should detect the floor of the entrance / exit 63, the laser sensors 11_a2 and 11_a6 one step inside should detect the pallet, and the central laser sensors 11_a3, 11_a4, and 11_a5 should detect the loaded cargo. If the AGV 5 is transporting an empty pallet, the laser sensors 11_b2 to 11_b6 other than those at the ends should detect the pallet, as in the example of the entrance / exit 63b in FIG. 12. Based on this assumption, the determination unit 123 compares the height of the object measured from the detection data of the laser sensors 11_a1 to 11_a7 with the expected height of the cargo. For example, in steps S504a and S504g, the measured height of the object is compared with the height of the floor. In steps S504b and S504f, the measured height of the object is compared with the height of the pallet loaded on the AGV 5. In steps S503c to S503e, the measured height of the object is compared with the height of the luggage loaded on the AGV 5.

[0096] If the height of each object matches the cargo height based on the transport plan (step S505; YES), the judgment unit 123 determines that the detected object is an AGV 5 that transports cargo according to the transport plan, and continues the operation of the palletizer 6 (step S506).

[0097] As an example of entrance / exit 63c in FIG. 12, assume that an object (human) other than the AGV 5 passes through. Since the width of a human is generally smaller than the width of a pallet, when a human passes through entrance / exit 63, the height of the object other than the floor surface is measured in a narrower range than the AGV 5 (pallet). In the example of entrance / exit 63c in FIG. 12, when a human passes through, the height is measured only in the narrow range of laser sensors 11_c5 to 11_c7, which is significantly different from the range in which the height expected when an AGV 5 passes through is measured (the range exemplified by entrances 63a and 63b in FIG. 12). Furthermore, the height of each part of the object (human) other than the AGV 5 does not match the height of the baggage or pallet loaded on the AGV 5. Therefore, when an object other than the AGV 5 passes through, it is likely that one or more laser sensors 11 will obtain a measurement result that does not match the baggage height when the AGV 5 passes through. Therefore, if the height of the object at at least one location does not match the cargo height based on the transportation plan (step S505; NO), the judgment unit 123 judges that the detected object is a foreign object or that there is a malfunction in the laser sensor 11.

[0098] FIG. 14 is a diagram illustrating the function of the safety control system according to the second embodiment. As in the example of the entrance / exit 63a in FIG. 14, depending on the number of packages transported by the AGV 5, packages may be stacked only partially on the top layer. Therefore, in steps S504a to S504g, the determination unit 123 determines that the heights do not match if the difference between the height of the object measured by the laser sensor 11 and the package height based on the transportation plan is greater than the height of each package. As a result, in the example of the entrance / exit 63a in FIG. 14, the height measured by the laser sensors 11_a3 and 11_a5 differs from the height of the transportation plan (the height of four layers of packages). However, since the difference is less than the height of each package, the determination unit 123 determines that the height measured by these laser sensors 11_a3 and 11_a5 matches the package height in the transportation plan. On the other hand, as in the example of the entrance / exit 63c in FIG. 14, when a person passes through, the difference in height should be greater than the height of each package. Therefore, the determination unit 123 determines that the height measured by the laser sensors 11_c5 to 11_c7 does not match the cargo height in the transportation plan. As a result, even if there is a portion on the top layer of the AGV 5 where no cargo is carried, the determination unit 123 can correctly determine that it is the AGV 5.

[0099] Furthermore, if the determining unit 123 determines that the detected object is a foreign object or that the laser sensor 11 is malfunctioning, the stop processing unit 124 brings the operation of the palletizer 6 to an emergency stop for safety reasons (step S507).

[0100] (Safety control system processing example 6) Fig. 15 is a second flowchart showing a processing example of the safety control system according to the second embodiment. Processing example 6 of the safety control system 10 will be described with reference to Fig. 15. Fig. 15 shows the flow of processing after the transport plan acquisition unit 122 acquires a transport plan (step S101 in Fig. 5). Note that processing example 6 is executed instead of processing example 5 described above.

[0101] The processing of steps S601 to S605 is the same as that of processing example 5 (steps S501 to S505 in FIG. 13). In processing example 6, if the height of an object at at least one location does not match the package height based on the transportation plan (step S605; NO), the determination unit 123 determines whether the height of an object measured by a laser sensor 11 adjacent to the laser sensor 11 where the mismatch occurs matches the package height based on the transportation plan (step S607). For example, assume that the height of an object measured by laser sensor 11_b4 at entrance / exit 63b in FIG. 14 does not match the package height (pallet height) in the transportation plan. In this case, the determination unit 123 determines whether the height of an object measured by adjacent laser sensors 11_b3 and 11_b5 matches the package height (pallet height) in the transportation plan.

[0102] If the height of the object measured by the adjacent laser sensors 11_b3 and 11_b5 matches the cargo height (pallet height) in the transportation plan (step S607; YES), the determination unit 123 determines that the laser sensor 11_b4 has made an erroneous detection (step S608). In this case, the determination unit 123 determines that the detected object is the AGV 5 that transports the cargo according to the transportation plan, and allows the palletizer 6 to continue operation (step S606).

[0103] On the other hand, if the height of the object measured by at least one of the adjacent laser sensors 11_b3 and 11_b5 does not match the height of the object in the transportation plan (step S605; NO), it is determined that the detected object is a foreign object or a malfunction of the laser sensor 11. In this case, the stop processing unit 124 brings the operation of the palletizer 6 to an emergency stop for safety reasons (step S609).

[0104] The safety control system 10 repeatedly executes the series of processes shown in FIG. 13 or FIG. 15 while the automatic picking system 100 is in operation, and monitors each entrance / exit 63 for abnormalities.

[0105] (Safety control system processing example 7) Fig. 16 is a third flowchart showing a processing example of the safety control system according to the second embodiment. Processing example 7 of the safety control system 10 will be described with reference to Fig. 16. Note that processing example 7 may be executed instead of processing example 5 or processing example 6 described above, or may be executed in parallel with processing example 5 or processing example 6.

[0106] First, the sensing data acquiring unit 121 acquires a time series of sensing data (step S701). The process of step S701 is the same as the process of the above-described processing example 4 (step S401 in FIG. 8).

[0107] Next, the judgment unit 123 compares the change pattern of the object's height obtained from the time series of detection data of the laser sensor 11 with the expected change pattern of the height (cargo height) according to the load of the AGV 5, which is recorded in advance in the storage 14.

[0108] FIG. 17 is a diagram illustrating an example of a time series of detection data according to the second embodiment. FIG. 17 illustrates an example of expected change patterns P1c and P1d of the measured height of the AGV 5, and an expected change pattern P2c of the measured height of a human for comparison. The horizontal axis of FIG. 17 represents time, and the vertical axis represents the measured height of the object. The expected change patterns P1c and P1d of the AGV 5 may be patterns calculated from the width and traveling speed of the AGV 5, or may be patterns created by collecting detection data from the laser sensor 11 in advance. The same applies to the expected change pattern P2c of the human. In the case of the AGV 5, the top surfaces of packages and pallets are flat as in the example of FIG. 12, resulting in expected change pattern P1c, in which periods of approximately constant measured height appear. Furthermore, even if packages are stacked only partially on the top layer as in the example of FIG. 14, the top surfaces of the individual packages are flat, resulting in expected change pattern P1d, in which multiple periods of approximately constant measured height appear. On the other hand, since humans do not have many flat areas on their upper surface, the expected change pattern P2c shows almost no period in which the measured height is approximately constant. As such, due to the differences in the shapes of the AGV 5 and humans, the expected change patterns P1c and P1d of the AGV 5 and the expected change pattern P2c of humans are significantly different. Therefore, by comparing the change patterns of the measured height, it is possible to distinguish between the AGV 5 and humans.

[0109] Based on this, the determination unit 123 compares the change pattern of the measured height obtained from the time series of the detection data of the laser sensor 11 with the expected change pattern of the measured height of the AGV 5 recorded in advance in the storage 14. Note that while FIG. 17 illustrates only two expected change patterns P1c and P1d of the measured height of the AGV 5, expected change patterns corresponding to each load content of the AGV 5 are recorded in advance. If the change pattern of the measured height of the laser sensor 11 matches any of the expected change patterns of the AGV 5 (step S702; YES), the determination unit 123 determines that the detected object is an AGV 5 transporting packages according to the transport plan and continues the operation of the palletizer 6 (step S703). On the other hand, if the change pattern of the detection width of the laser sensor 11 does not match any of the expected change patterns of the AGV 5 (step S702; NO), the determination unit 123 determines that the detected object is a foreign object or that the laser sensor 11 is malfunctioning. In this case, the stop processing unit 124 brings the operation of the palletizer 6 to an emergency stop for safety reasons (step S704). Note that, for example, in the case of the entrance 63a, the determination unit 123 performs determination for each of the laser sensors 11_a1 to 11_a7 provided at this entrance 63a. The same applies to the other entrances 63.

[0110] (Action and effect) As described above, in the safety control system 10 according to this embodiment, the laser sensors 11 are arranged at different horizontal positions and output detection data indicating the measured distance to the object, and the judgment unit 123 judges that an abnormality has occurred if the height of the object determined from the measured distance of at least one laser sensor 11 does not match the height of the cargo determined from the transportation plan.

[0111] By doing this, the safety control system 10 can accurately determine whether the AGV 5 is passing through according to the transport plan or whether an abnormality has occurred, based on the detection data of the laser sensor 11, which is installed at the entrance / exit 63 of the work area 60 where a safety fence cannot be installed so as not to obstruct the movement of the AGV 5.

[0112] In addition, if the height of an object estimated from the measurement distance of a first laser sensor, which is one of the multiple laser sensors 11, does not match the height of the luggage identified from the transportation plan, and if the height of an object estimated from the measurement distance of a second laser sensor adjacent to the first laser sensor matches the height of the luggage identified from the transportation plan, the judgment unit 123 determines that the AGV 5 is passing through the entrance / exit 63 in accordance with the transportation plan.

[0113] In this way, the safety control system 10 can distinguish whether an AGV 5 carrying cargo according to the transport plan is passing through, or whether a foreign object (such as a human or an AGV 5 with its cargo falling) that is different from the transport plan is passing through, or whether a malfunction has occurred in the laser sensor 11.

[0114] The judgment unit 123 judges that an abnormality has occurred if the change pattern of the measured distance when an object passes through the entrance / exit 63 identified from the time series of the detection data does not match the predetermined expected change pattern of the AGV 5.

[0115] By doing this, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account the difference in shape between the AGV 5 and a foreign object (human).

[0116] <Third embodiment> Next, the third embodiment will be described in detail with reference to Fig. 18. Components common to the above-described embodiments will be given the same reference numerals and detailed description will be omitted.

[0117] Fig. 18 is a diagram showing an example of the arrangement of laser sensors according to the third embodiment. Fig. 18 shows an example of the arrangement of laser sensors 11 at entrances 63a to 63c provided on one side of the work area 60. The safety control system 10 of this embodiment has both a plurality of laser sensors 11 installed at different horizontal positions and a plurality of laser sensors 11 installed at different vertical heights. In the example of Fig. 18, seven laser sensors 11_1a to 11_a7, 11_b1 to 11_b7, and 11_c1 to 11_c7 are provided at each of the entrances 63a, 63b, and 63c at different horizontal positions on a support part 64 above the work area 60. Furthermore, eight laser sensors 11_a11 to 11_a18, 11_b11 to 11_b18, and 11_c11 to 11_c18 are provided at different vertical heights on the pillars 62 of the entrances 63a, 63b, and 63c. Note that Fig. 18 is just an example, and the number of laser sensors 11 and their installation intervals can be changed as desired.

[0118] In this embodiment, the safety control system 10 executes the process examples of the first and second embodiments in parallel. For example, for the entrance 63a, the safety control system 10 executes one or a combination of process examples 1 to 4 of the first embodiment based on the detection data of the laser sensors 11_a11 to 11_a18 provided on the pillar 62. The safety control system 10 also executes one or a combination of process examples 5 to 7 of the second embodiment based on the detection data of the laser sensors 11_a1 to 11_a7 provided on the support 64. In this way, the safety control system 10 can estimate the width and height of an object passing through the entrance 63a, thereby grasping the shape of the object more accurately than the above-described embodiments. That is, although the resolution is low, measurement data (shape data) of an object can be obtained using an inexpensive configuration similar to a 3D scanner. This makes it possible to more accurately distinguish whether the detected object is being passed by the AGV 5 according to the transport plan, or whether an abnormality has occurred (a foreign object other than the AGV 5 passing by, an AGV 5 with its cargo in a collapsed state passing by, or a malfunction of the laser sensor 11).

[0119] <Other embodiments> Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0120] <Additional Notes> The above-described embodiment can be understood, for example, as follows.

[0121] (1) According to the first aspect, the safety control system 10 includes a plurality of laser sensors 11 arranged at different vertical heights or different horizontal positions at an entrance / exit 63 through which the AGV 5 enters or exits the work area 60 of the palletizer 6, and capable of detecting objects present at the entrance / exit 63; a detection data acquisition unit 121 that acquires detection data from each of the laser sensors 11; a transport plan acquisition unit 122 that acquires a transport plan for the AGV 5; and a judgment unit 123 that judges, based on the detection data and the transport plan, whether the AGV 5 is passing through the entrance / exit 63 in accordance with the transport plan or whether an abnormality has occurred.

[0122] In this way, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transportation plan or whether a foreign object different from the transportation plan is passing.

[0123] (2) According to the second aspect, in the safety control system 10 according to the first aspect, the judgment unit 123 judges that an abnormality has occurred if the timing at which the laser sensor 11 outputs detection data indicating that an object has been detected does not match the transport timing of the AGV 5 identified from the transport plan.

[0124] In this way, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transportation plan or whether a foreign object different from the transportation plan is passing.

[0125] (3) According to the third aspect, in the safety control system 10 relating to the first or second aspect, the laser sensors 11 are arranged at different heights in the vertical direction, and the judgment unit 123 outputs detection data indicating that a first laser sensor, which is one of the multiple laser sensors 11, has detected an object, outputs detection data indicating that a second laser sensor arranged above the first laser sensor does not detect an object, and determines that an abnormality has occurred if the installation height of the second laser sensor is equal to or lower than the cargo height of the luggage identified from the transportation plan.

[0126] In this way, the safety control system 10 can distinguish whether an AGV 5 carrying cargo according to the transport plan is passing through, or whether a foreign object (such as a human or an AGV 5 with its cargo falling) that is different from the transport plan is passing through, or whether a malfunction has occurred in the laser sensor 11.

[0127] (4) According to the fourth aspect, in the safety control system 10 relating to the first or second aspect, the laser sensors 11 are arranged at different vertical heights and output detection data indicating the measured distance to the object, and the judgment unit 123 outputs detection data indicating that a first laser sensor, which is one of the multiple laser sensors 11, has detected an object, and outputs detection data indicating that a second laser sensor arranged higher than the first laser sensor does not detect the object, and if the installation height of the second laser sensor is equal to or less than the cargo height of the cargo identified from the transportation plan, and if the detection width of the object estimated from the measured distance to the object by the first laser sensor matches the cargo width of the cargo identified from the transportation plan, it is judged that the AGV 5 is passing through the entrance / exit 63 in accordance with the transportation plan.

[0128] By doing this, when the laser sensor 11 is a ranging sensor, even if a false detection occurs in the second laser sensor, the safety control system 10 can correctly determine that the AGV 5 is passing according to the transportation plan from the detection data of the first laser sensor.

[0129] (5) According to the fifth aspect, in the safety control system 10 relating to any one of the first to fourth aspects, the laser sensors are arranged at different heights in the vertical direction, and the judgment unit 123 judges that an abnormality has occurred if the detection pattern when an object passes through the entrance / exit 63 identified from the time series of the detection data does not match the expected detection pattern of the AGV 5 that has been set in advance.

[0130] By doing this, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account that the detection patterns differ between the AGV 5 and foreign objects (humans).

[0131] (6) According to the sixth aspect, in the safety control system 10 relating to any one of the first to fourth aspects, the laser sensors 11 are arranged at different vertical heights and output detection data indicating the measured distance to the object, and the judgment unit 123 judges that an abnormality has occurred if the change pattern of the detection width of the object passing through the entrance / exit 63 estimated from the time series of the detection data does not match the expected change pattern of the detection width of the AGV 5 that has been set in advance.

[0132] By doing this, when the laser sensor 11 is a distance measurement sensor, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account the different shapes of the AGV 5 and the foreign object (human).

[0133] (7) According to the seventh aspect, in the safety control system 10 relating to any one of the first to sixth aspects, the laser sensors 11 are arranged at different positions horizontally and output detection data indicating the measured distance to the object, and the judgment unit 123 judges that an abnormality has occurred if the height of the object determined from the measured distance of at least one laser sensor 11 does not match the height of the cargo determined from the transportation plan.

[0134] By doing this, the safety control system 10 can accurately determine whether the AGV 5 is passing through according to the transport plan or whether an abnormality has occurred, based on the detection data of the laser sensor 11, which is installed at the entrance / exit 63 of the work area 60 where a safety fence cannot be installed so as not to obstruct the movement of the AGV 5.

[0135] (8) According to the eighth aspect, in the safety control system 10 relating to any one of the first to seventh aspects, the laser sensors 11 are arranged at different positions horizontally and output detection data indicating the measured distance to the object, and the judgment unit 123 judges that the AGV 5 is passing through the entrance / exit 63 in accordance with the conveyance plan when the height of the object estimated from the measured distance of a first laser sensor, which is one of the multiple laser sensors, does not match the height of the luggage identified from the conveyance plan, and when the height of the object estimated from the measured distance of a second laser sensor adjacent to the first laser sensor matches the height of the luggage identified from the conveyance plan.

[0136] In this way, the safety control system 10 can distinguish whether an AGV 5 carrying cargo according to the transport plan is passing through, or whether a foreign object (such as a human or an AGV 5 with its cargo falling) that is different from the transport plan is passing through, or whether a malfunction has occurred in the laser sensor 11.

[0137] (9) According to the ninth aspect, in the safety control system 10 relating to any one of the first to eighth aspects, the laser sensor 11 is arranged at different positions in the horizontal direction and outputs detection data indicating the measured distance to the object, and the judgment unit 123 judges that an abnormality has occurred if the change pattern of the measured distance when the object passes through the entrance / exit 63 identified from the time series of the detection data does not match the expected change pattern of the AGV 5 that has been set in advance.

[0138] By doing this, the safety control system 10 can distinguish whether the AGV 5 is passing according to the transport plan or whether a foreign object other than the AGV 5 is passing, taking into account the difference in shape between the AGV 5 and a foreign object (human).

[0139] (10) According to the tenth aspect, in the safety control system 10 relating to the first or second aspect, the laser sensor 11 has a plurality of laser sensors 11 arranged at different heights in the vertical direction and a plurality of laser sensors 11 arranged at different positions in the horizontal direction.

[0140] In this way, the safety control system 10 can estimate the width and height of an object passing through the entrance / exit 63, and therefore can grasp the shape of the object more accurately. That is, although the resolution is low, it is possible to obtain measurement data (shape data) of the object like a 3D scanner with an inexpensive configuration. This makes it possible to more accurately distinguish whether the detected object is being passed by the AGV 5 according to the transport plan or whether an abnormality has occurred (a foreign object other than the AGV 5 passing, an AGV 5 with its cargo collapsed, or a malfunction of the laser sensor 11).

[0141] (11) According to an eleventh aspect, the safety control system 10 according to any one of the first to tenth aspects further includes a stop processing unit 124 that stops the palletizer 6 when it is determined that an abnormality has occurred.

[0142] In this way, if any abnormality occurs (such as a worker entering the work area 60, a load shift on the AGV 5, or a malfunction of the laser sensor 11), the safety control system 10 can stop the operation of the palletizer 6 to ensure the safety of the worker and prevent damage caused by contact between the AGV 5 and the palletizer 6.

[0143] (12) According to the twelfth aspect, the safety control method includes the steps of acquiring detection data from a plurality of laser sensors 11 that are arranged at different vertical heights or different horizontal positions at an entrance / exit 63 through which the AGV 5 enters or exits the work area 60 of the palletizer 6 and that can detect objects present at the entrance / exit 63; acquiring a transport plan for the AGV 5; and determining, based on the detection data and the transport plan, whether the AGV 5 is passing through the entrance / exit 63 in accordance with the transport plan or whether an abnormality has occurred.

[0144] (13) According to the thirteenth aspect, the program causes the safety control system 10 to execute the following steps: acquiring detection data from each of a plurality of laser sensors 11 that are arranged at different vertical heights or different horizontal positions at an entrance / exit 63 through which the AGV 5 enters or exits the work area 60 of the palletizer 6 and that can detect objects present at the entrance / exit 63; acquiring a transport plan for the AGV 5; and determining, based on the detection data and the transport plan, whether the AGV 5 is passing through the entrance / exit 63 in accordance with the transport plan or whether an abnormality has occurred. [Explanation of symbols]

[0145] 100 Automatic Picking System 1. Upper system 2. Warehouse equipment control system 3. Automated guided vehicle (AGV) robot control system 4 Palletizer robot control system 5. Automated guided vehicle (AGV) 6 Palletizer 60 working area 62 pillars 63 Entrance / Exit 64 Support part 10 Safety Control System 11 Laser sensor 12 processors 121 Detection data acquisition unit 122 Transportation Plan Acquisition Department 123 Judgment section 124 Stop processing unit 13. Memory 14. Storage 15 Communication Interface

Claims

1. a plurality of laser sensors arranged at different heights vertically or at different positions horizontally at entrances through which the automatic transport device enters or exits a work area of ​​the palletizer, the laser sensors being capable of detecting an object present at the entrances; a detection data acquisition unit that acquires detection data from each of the laser sensors; a transportation plan acquisition unit that acquires a transportation plan for the automatic transportation device; a determination unit that determines whether the automatic transport device is passing through the entrance / exit in accordance with the transport plan or whether an abnormality has occurred, based on the detection data and the transport plan; A safety control system comprising:

2. the determination unit determines that an abnormality has occurred when a timing at which the laser sensor outputs detection data indicating that the object has been detected does not match a transport timing of the automatic transport device identified from the transport plan. The safety control system according to claim 1 .

3. the laser sensors are positioned at different vertical heights; the determination unit determines that an abnormality has occurred when a first laser sensor, which is one of the plurality of laser sensors, outputs detection data indicating that an object has been detected, a second laser sensor arranged above the first laser sensor outputs detection data indicating that an object has not been detected, and the installation height of the second laser sensor is equal to or less than the height of the package identified from the transportation plan. The safety control system according to claim 1 or 2.

4. the laser sensors are arranged at different heights in a vertical direction and output detection data indicating a measured distance to the object; the determination unit outputs detection data indicating that a first laser sensor, which is one of the plurality of laser sensors, has detected an object, and outputs detection data indicating that a second laser sensor, which is positioned above the first laser sensor, has not detected an object; and if the installation height of the second laser sensor is equal to or less than the height of the luggage identified from the transportation plan, and if the detection width of the object estimated from the measured distance to the object by the first laser sensor matches the luggage width identified from the transportation plan, determines that the automatic transportation device is passing through the entrance / exit in accordance with the transportation plan. The safety control system according to claim 1 or 2.

5. the laser sensors are positioned at different vertical heights; the determination unit determines that an abnormality has occurred when a detection pattern when an object passes through the entrance / exit identified from the time series of the detection data does not match a predetermined assumed detection pattern of the automatic transport device. The safety control system according to claim 1 or 2.

6. the laser sensors are arranged at different heights in a vertical direction and output detection data indicating a measured distance to the object; the determination unit determines that an abnormality has occurred when a change pattern of the detection width of an object passing through the entrance / exit estimated from the time series of the detection data does not match a predetermined expected change pattern of the detection width of the automatic transport device. The safety control system according to claim 1 or 2.

7. the laser sensors are arranged at different positions in a horizontal direction and output detection data indicating a measured distance to the object; the determination unit determines that an abnormality has occurred when a height of an object identified from a measurement distance of at least one of the laser sensors does not match a height of a package of luggage identified from the transportation plan. The safety control system according to claim 1 or 2.

8. the laser sensors are arranged at different positions in a horizontal direction and output detection data indicating a measured distance to the object; the determination unit determines that the automatic conveying device is passing through the entrance / exit in accordance with the conveying plan when the height of an object estimated from the measurement distance of a first laser sensor, which is one of the plurality of laser sensors, does not match the height of the luggage identified from the conveying plan, and when the height of an object estimated from the measurement distance of a second laser sensor adjacent to the first laser sensor matches the height of the luggage identified from the conveying plan; The safety control system according to claim 1 or 2.

9. the laser sensors are arranged at different positions in a horizontal direction and output detection data indicating a measured distance to the object; the determination unit determines that an abnormality has occurred when a change pattern of the measured distance when an object passes through the entrance / exit identified from the time series of the detection data does not match a predetermined expected change pattern of the automatic transport device. The safety control system according to claim 1 or 2.

10. The laser sensor includes a plurality of laser sensors arranged at different heights in the vertical direction and a plurality of laser sensors arranged at different positions in the horizontal direction. The safety control system according to claim 1 or 2.

11. further comprising a stop processing unit that stops the palletizer when it is determined that an abnormality has occurred. The safety control system according to claim 1 or 2.

12. acquiring detection data from a plurality of laser sensors that are arranged at different heights vertically or at different positions horizontally at entrances through which the automatic transport device enters or exits a work area of ​​the palletizer and that can detect an object present at the entrances; acquiring a transportation plan for the automatic transportation device; a step of determining whether the automated transport device is passing through the entrance / exit in accordance with the transport plan or whether an abnormality has occurred, based on the detection data and the transport plan; A safety control method comprising:

13. acquiring detection data from a plurality of laser sensors that are arranged at different heights vertically or at different positions horizontally at entrances through which the automatic transport device enters or exits a work area of ​​the palletizer and that can detect an object present at the entrances; acquiring a transportation plan for the automatic transportation device; a step of determining whether the automated transport device is passing through the entrance / exit in accordance with the transport plan or whether an abnormality has occurred, based on the detection data and the transport plan; A program that causes the safety control system to execute the above.

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