JP7176926B2 - Foreign object detection method and system - Google Patents

Description

The present disclosure relates to a method and system for detecting foreign objects other than vehicles in areas where vehicles stop, such as parking lots.

In a space where a vehicle enters and stops, such as an entry/exit space in a mechanical parking lot, the operator must be present in addition to the vehicle when performing operations such as opening and closing the entrance door and transporting a pallet on which the vehicle is placed. It is necessary to confirm that there are no foreign objects such as passengers, passengers, or baggage. Such confirmation work for the absence of foreign matter can be performed visually by the driver or facility staff. Therefore, in recent years, there has been a demand for a technique for automatically detecting foreign matter in a target area without relying only on human power, so as to reliably confirm the absence of foreign matter.

In addition, if the autonomous driving technology that is currently being developed in various countries is put into practical use, it will not only be possible to drive the vehicle, but also various things around the vehicle such as opening and closing the door and transporting pallets as described above. It can be assumed that automation will also be promoted for the operation of For example, after the vehicle delivers the occupants to their destination, the vehicle automatically moves to a nearby mechanical parking lot and is stored in a storage space. It will move in the state and stop at the loading/unloading space. At this time, operations such as opening and closing the door and starting the movement of the pallet may be executed by visually confirming the absence of foreign matter and inputting an operation button by a staff member. It will be smoother if there is a mechanism to confirm and start the operation.

Such a mechanism for detecting a foreign object may be widely required not only in a mechanical parking lot but also in a place where some kind of operation is performed around a stopped vehicle, such as a power feeding facility for an electric vehicle.

Techniques for automatically detecting a foreign object in a target area into which a vehicle enters include, for example, the technique described in Patent Document 1 below. Patent Literature 1 describes a technology for detecting the presence of a person by laying a mat switch made of a piezoelectric sheet over the entire floor surface of an external communication portion other than a pallet in a multi-storey parking lot. However, in the case of the technique described in Patent Document 1, it is not possible to detect a person or a foreign object on a pallet or the like on which no mat switch is installed.

Therefore, techniques such as those described in Patent Documents 2 and 3 below, for example, have been proposed as techniques capable of detecting foreign matter in areas other than areas where mat switches and the like can be laid. Patent Literature 2 describes a parking area detection device that includes a range sensor in the parking area of a mechanical parking facility and detects an object on the floor from the scanning information of the range sensor. Among the data detected by the range sensor, the storage detection device treats data of a predetermined size or larger as candidate data, and recognizes data other than those recognized as automobile tires as residue.

Patent Literature 3 describes an area detection device including a range sensor (detection means) and a control device (control means). The range sensor detects the position, size, and shape of a vehicle that has entered the boarding/alighting area of the mechanical parking facility, and acquires vehicle contour data. The control device stores the state of the lingering detection range excluding the range of the vehicle outline data in the boarding/alighting area as initial data for entering the parking lot, and compares it with the real-time data to determine whether or not there is a difference.

JP-A-06-173483 JP 2015-161080 A JP 2014-80735 A

However, in the techniques as described in Patent Documents 2 and 3, it is required to perform advanced arithmetic processing on data in detecting a foreign object. In the case of the storage unit detection device described in Patent Document 2, first, objects of a predetermined size or larger are selected from the detection data as candidate data, and those with a close center of gravity position are associated as the same object from the candidate data, and are recognized as tires. . Complicated calculations are required for the process of detecting the size of the object from the detected data and identifying and associating the position of the center of gravity of the object from the candidate data.

Further, in the case of the area detection device described in Patent Document 3, the two-dimensional or three-dimensional outline of the vehicle is acquired based on the scanning by the range sensor. Most of the surfaces of vehicles have complicated shapes, and complex calculations are required to create vehicle contour data from range sensor data.

As described above, the technology for automatically detecting a foreign object generally requires a high degree of computation. For this reason, there is a possibility that the smooth operation of a mechanical parking facility or the like may be hindered, for example, it may take a long time to calculate data when entering or exiting a vehicle.

Therefore, in the present disclosure, a foreign object detection method and system that can easily detect a foreign object in a target area will be described.

In the present disclosure, a range sensor that measures the inside of a target area into which a vehicle enters is arranged with respect to the target area, the vehicle is stopped at the stop position of the target area, and there is no foreign object in the target area, a step of acquiring detected point data by the range sensor as reference data; a step of acquiring the detected point data by the range sensor at an arbitrary point in time when the vehicle is stopped at a stop position in the target area ; a step of comparing detected point data including detected points in an area where the vehicle is stopped acquired at an arbitrary time with the reference data including detected points in an area where the vehicle is stopped; This invention relates to a foreign matter detection method for executing a foreign matter detection step including the step of determining that a foreign matter exists in the target area at the arbitrary time when the above difference is found.

In the foreign matter detection method described above, the reference data may be detected point data acquired when the vehicle enters the target area and stops at a stop position within the target area.

In the foreign matter detection method described above, in addition to the foreign matter detection step, as the vehicle enters the target region, the range sensor is operated to measure the target region from time to time; a step of comparing the detected point data acquired at the previous point with the detected point data acquired at the previous point; Additionally, a vehicle stop determination process including a step of determining that the vehicle has stopped may be executed.

In the above-described foreign object detection method, as the reference data, in the vehicle stop determination step, immediately before the vehicle stop determination is made, the difference between detected point data is equal to or less than a predetermined value. or the detected point data acquired immediately after it is determined that the vehicle has stopped in the vehicle stop determining step.

In addition, the present disclosure is provided with a range sensor that measures the inside of a target area into which a vehicle enters , and the vehicle is stopped at a stop position of the target area, and the range sensor is used in a state where there is no foreign object in the target area. Acquisition of detected point data as reference data, acquisition of detected point data by the range sensor at an arbitrary point in time when the vehicle is stopped at a stop position in the target area, and acquisition of the detected point data at the arbitrary point in time. The detected point data including the detected points in the stopped area is compared with the reference data including the detected points in the stopped area of the vehicle. It relates to a foreign object detection system configured to determine that a foreign object is present in a target area at a point in time.

In the foreign matter detection system described above, two or more range sensors are installed for the target area, and can be arranged so that the measurement range includes the entire circumference of the stop position of the vehicle in a plan view.

According to the foreign matter detection method and system of the present invention, it is possible to obtain the excellent effect of being able to easily detect foreign matter in the target area.

1 is a schematic plan view illustrating the overall configuration of a foreign object detection system according to an embodiment of the present disclosure; FIG. 4 is a flowchart for explaining an example of a vehicle stop determination procedure according to the present embodiment. 4 is a flowchart for explaining an example of the procedure of a foreign matter detection process in the embodiment;

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the foreign object detection system of the present embodiment shown in FIG. 1, the target area A is assumed to be a parking space for mechanical parking equipment. A pallet 2 for transporting a vehicle 1 enters and exits the target area A, and the area above the pallet 2 is set as a stop position P of the vehicle 1. - 特許庁Then, when there is an object (foreign object) O other than the vehicle 1 stopped at the stop position P within the target area A, the foreign object O is detected. In addition, the "foreign object" is an object other than the vehicle existing in the target area, and an object other than the object originally installed in the target area. It also refers to baggage, etc. FIG. 1 shows two foreign substances O within the target area A as an example.

The target area A, which is the loading/unloading space, is a space surrounded by walls on all four sides, with a transport port 3 on the back side (upper side in the figure) and a loading/unloading port 4 on the front side (lower side in the figure). ing. A pallet 2 for transporting a vehicle 1 enters and exits the target area A, which is a loading/unloading space, from a storage space (not shown) outside the target area A through the transport port 3 . The home position of the pallet 2 in the target area A is the central part of the target area A. FIG. At the time of warehousing, the vehicle 1 enters the object area A through the entrance/exit 4, stops at the stop position P on the pallet 2, and is transported together with the pallet 2 from the transport entrance 3 to the storage space and stored. When leaving the warehouse, the vehicle 1 is transported from the storage space through the transport opening 3 into the target area A together with the pallet 2 , and then leaves the target area A through the entrance/exit 4 .

In the target area A, a range sensor 5 for measuring within the target area A is arranged. The range sensor 5 is a device that irradiates the surrounding space with laser light, ultrasonic waves, or the like as irradiation waves and detects reflected waves, as indicated by arrows in FIG. The radiation wave from the ranging sensor 5 reaches the surrounding objects or structures such as walls, floors, and pillars and is reflected. 5 and the angle with respect to the range sensor 5 are acquired as data (a point within the target area A whose reflected wave is detected by the range sensor 5 is hereinafter referred to as a detected point).

In this embodiment, two range sensors 5 are arranged at corners forming diagonal lines with respect to the target area A, which has a rectangular shape in plan view. In this way, by arranging the pair of range sensors 5 so as to sandwich the stop position P of the vehicle 1, the entire circumference of the stop position P in a plan view can be included in the measurement range of the range sensors 5. . In principle, the irradiated wave travels straight. Therefore, if only one range sensor 5 is arranged for the target area A, the measurement range outside. Therefore, by arranging the range sensor 5 as shown in FIG. 1, it is possible to detect a foreign object in the entire area around the vehicle 1 without omission. It should be noted that the number and arrangement of the range sensors 5 shown here are just an example, and three or more range sensors 5 are arranged in the target area A in order to increase the accuracy of measurement and to secure a wide measurable range. It may be arranged oppositely.

Data of each detected point acquired by the range sensor 5 (hereinafter referred to as "detected point data") is input to the control device 6 as a measurement signal 5a. The control device 6 is a device that monitors the entire mechanical parking lot including the target area A, which is the parking space for entering and leaving, and operates each part. It controls the operation of the range sensor 5 and the like.

A warehousing switch 7 is provided on the outer wall near the entrance/exit 4 . When the warehousing switch 7 is operated, a warehousing signal 7 a is input to the control device 6 . In the control device 6, on the condition that the warehousing signal 7a is input, each process related to the warehousing of the vehicle 1, that is, the transportation of the pallet 2, the opening of the entrance/exit door 4, and the stop determination process described later are executed. It has become. The installation position of the warehousing switch 7 is not limited to the example shown here, and an appropriate position suitable for the operation of the entrance/exit 4 can be selected.

In addition, alarm devices 8 are provided at various locations inside and outside the target area A. As shown in FIG. The alarm device 8 is a device that issues an alarm in the area (including the target area A) managed by the control device 6 when an event requiring the attention of personnel occurs. It is activated by the input of 8a. ``Some situation that requires the attention of personnel'' means, for example, when the vehicle 1 is moved to a storage space outside the target area A, as a result of executing a foreign object detection process described later, an object other than the vehicle 1 is detected in the target area A. For example, a foreign object O is detected. The content of the warning may be any type, such as an alarm sound, lighting of a warning light, display of a warning message, etc., as long as it can call attention to personnel, and an appropriate format can be selected.

In the example shown here, the alarm device 8 is illustrated on the inner wall of the target area A and the outer wall near the entrance/exit 4, but the alarm device 8 may be provided at other locations as necessary. . For example, the alarm device 8 can be provided in a control room of a mechanical parking lot (not shown).

Various signals such as the measurement signal 5a, the warehousing signal 7a, and the alarm signal 8a may be exchanged in a wired or wireless manner. As an example, devices such as the control device 6, the range sensor 5, the warehousing switch 7, and the alarm device 8 can be connected via Ethernet (registered trademark) or the like so that they can communicate with each other.

Next, the operation of the present embodiment described above will be described.

In the foreign object detection system of the present embodiment shown in FIG. 1, not only can foreign objects O in the target area A be detected, but also whether or not the vehicle 1 has stopped at the stop position P can be determined. First, the stop determination of the vehicle 1 will be described.

Stop determination is performed by the control device 6 on the condition that the warehousing signal 7a is input. In the example shown here, the input of the warehousing signal 7 a is performed by operating the warehousing switch 7 . That is, when the vehicle 1 stops in front of the entrance/exit 4, the driver of the vehicle 1 or an occupant such as a mechanical parking attendant operates the parking switch 7, thereby inputting the parking signal 7a. be. However, this is only an example, and the input of the warehousing signal 7a may be performed by other methods. For example, when the vehicle 1, which is an automatic driving vehicle, moves in front of the entry/exit door 4 of the target area A, which is the entry/exit space, in an unmanned state, and enters automatically, there may be a situation where there is no person to operate the entry switch 7. is assumed. In such a case, for example, a sensor for detecting the vehicle 1 may be separately provided in front of the entrance/exit 4, and when the vehicle 1 is detected by the sensor, the detection signal may be treated as the warehousing signal. Alternatively, some signal may be output from the vehicle 1 and the control device 6 may recognize the signal as the warehousing signal.

When the warehousing signal 7a is input, the control device 6 opens the entrance/exit 4. As shown in FIG. At the start of warehousing, the entry/exit port 4 is opened with an empty pallet 2 arranged at the central portion, which is a fixed position in the target area A. If the empty pallet 2 does not exist in the target area A at the time when the start of warehousing is instructed, the transport port 3 is opened to transport the empty pallet 2 to the target area A and arrange it in the central part. After that, the entrance/exit 4 is opened. Then, the stop determination process shown in FIG. 2 is started.

When the entrance/exit 4 is opened, the vehicle 1 moves toward the pallet 2 in the target area A at slow speed. The control device 6 activates each range sensor 5 and performs measurement within the target area A with each range sensor 5 (step S1). Each range sensor 5 acquires detected point data from the reflected wave. This detected point data is the distance from each range sensor 5 and the angle with respect to each range sensor 5 of a large number of points where irradiation waves are reflected on the surface of a structure or object within the target area A at a certain point in time. is. The detected point data is input to the control device 6 as the measurement signal 5a.

In step S2, the range sensor 5 measures the target area A in the same way as in step S1. After step S1, the measurement in step S2 is repeatedly performed moment by moment.

Then, in steps S3 and S4, the detected point data acquired in the latest step S2 is compared with the detected point data acquired in the previous step S1. In step S3, the difference between both data is calculated. This difference data is calculated with respect to the detected point data acquired for each range sensor 5 . Then, after performing processing such as downsampling and noise removal, in the next step S4, for each range sensor 5, it is determined whether or not the number of detection points remaining in the difference data is less than the threshold.

If there is no difference in the presence/absence, position, angle, etc. of an object in the target area A between a certain time point and another time point, the detected point data acquired at the certain time point and the detected point data acquired at the other time point The data of the detection point thus obtained matches as long as noise and the like are not taken into account. That is, since the difference between the detected point data at both times is zero, the detected point does not remain in the differential data. On the other hand, if the object moves within the target area A, the detected point data will differ between the two points in time, so the detected point will remain in the differential data. That is, in step S4, it is determined whether or not there is a predetermined difference or more between the data of the detected points before and after each range sensor 5 is measured. Judge. Of course, the movement within the target area A assumed here is the movement of the vehicle 1 to the stop position P. As shown in FIG.

If the number of detected points remaining in the difference data for one or more range sensors 5 is equal to or greater than the threshold, the process returns from step S4 to step S2, and the range sensors 5 perform measurement again. Then, the detected point data acquired here is compared with the detected point data acquired last time in the next steps S3 and S4. That is, in step S3, the difference between the detected point data obtained in immediately preceding step S2 and the detected point data obtained in previous step S2 is calculated, and the difference data is determined in subsequent step S4. Steps S2 to S4 are repeated until the number of detected points remaining in the difference data is less than the threshold. While the number of detected points remaining in the difference data is greater than or equal to the threshold, it is considered that the vehicle 1 is not stationary and is moving. The measurement is repeated until it is determined that the

If it is determined in step S4 that the number of detection points remaining in the difference data calculated in immediately preceding step S3 is less than the threshold for all range sensors 5, the process proceeds to step S5. In step S5, whether the state determined as YES in step S4, that is, "the state in which the number of detected points remaining in the difference data is less than the threshold value for all range sensors 5" continues for a predetermined time or longer. determine whether or not That is, the duration of the state in which the difference between the detected point data obtained in the most recent step S2 and the previous step S2 or step S1 is equal to or less than a predetermined value is determined.

If the continuation time of this state is less than the predetermined value, the process returns to step S2, and steps S2 to S5 are repeated until the continuation of the state becomes equal to or longer than the predetermined time. Then, when it is determined in step S5 that the duration of the state is equal to or longer than the predetermined value, it is determined that the vehicle 1 has stopped at the stop position P (step S6). When the vehicle 1 is moved to the stop position P on the pallet 2, it can be assumed that the vehicle 1 stops temporarily and resumes movement. Therefore, it is determined that the vehicle 1 has stopped at the target stop position P with certainty.

The stop determination itself is completed up to step S6, but in this embodiment, detected point data to be used in the subsequent foreign matter detection step (see FIG. 3) is subsequently acquired. When it is determined that the vehicle 1 has stopped at the stop position P, the process proceeds to step S7, the range sensor 5 is activated, and the detected point data at the point immediately after it is determined that the vehicle 1 has stopped is acquired. In step S8, the detected point data obtained in step S7 is stored as reference data when the vehicle 1 is stopped, and the process is terminated.

Here, before repeating steps S2 to S3, step S1 is executed as a step of obtaining the first detected point data, but this step S1 is not necessarily required. For example, step S1 may be omitted, and in the first step S3 in the stoppage determination process, the detected point data obtained in the immediately preceding step S2 may be compared with Null data. In this case, the difference data calculated in the first step S3 is always detected point data equal to or larger than the threshold value, and it is determined that the vehicle 1 is moving.

Also, the timing of acquiring the detected point data to be used as the reference data is not limited to the example described here. If it is detected point data acquired by the range sensor 5 in a state where the vehicle 1 is stopped within the stop position P within the target area A and it is considered that there is no foreign object O within the target area A, then the reference It can be used as data. For example, in the stop determination process of the vehicle 1 shown in FIG. The detected point data obtained in (1) may be used as the reference data.

In the process shown in FIG. 2, steps S2 to S4 are repeated until it is determined in step S5 that the duration of the predetermined state has exceeded a predetermined value. continues. In other words, the detected point data acquired in step S2 during this period is "a detected point in a state where the vehicle 1 is stopped within the stop position P within the target area A and no foreign object O exists within the target area A." can be thought of as data. Therefore, if a YES determination is made in step S5, the detected point data acquired in step S2 while the YES determination in step S4 was continued until the determination in step S5 is made is stored as reference data. of. Even in this way, it can be considered that it is "detected point data when the vehicle 1 stops at the stop position P within the target area A" and "acquired in a state where there is no foreign object O within the target area A". can be acquired as reference data.

Here, the case of using this system for foreign matter detection as shown in FIG. It is not necessary for the system to have both stop judgment and foreign object detection functions. While the process of detecting a foreign object, which will be described later, is performed by the system shown in FIG. However, in order to smoothly coordinate the movement and stopping of the vehicle 1 in the target area A and various operations around the vehicle 1, it is necessary to stop the vehicle 1 by a system for foreign matter detection as in the present embodiment. can also be determined, it is advantageous in terms of simplification of system configuration and speeding up of operation. Alternatively, a plurality of systems may be used in combination such that a stop determination is performed by a system such as that of the present embodiment and a stop determination is also performed by a separately installed sensor or the like.

Next, the foreign matter detection process will be described with reference to FIG.

The foreign matter detection process can be started at any timing when the state within the target area A is desired to be confirmed. For example, if there is a driver or a passenger in the vehicle 1 at the time of warehousing, or if there is a staff member in the target area A, the transportation of the vehicle 1 by the pallet 2 is started after the vehicle 1 stops at the stop position P. Before, it can be assumed that it is necessary to confirm that the area of interest A is unoccupied. In that case, the foreign matter detection step is automatically started immediately after the series of steps shown in FIG. Alternatively, the foreign matter detection process may be started at the time when the transportation of the vehicle 1 is instructed by operating a switch or the like (not shown), the transportation may be performed when the foreign matter O is not detected, and the transportation may be stopped when the foreign matter O is detected. good. Also, when closing the entrance/exit 4, it is conceivable that the foreign matter detection process is executed to confirm the absence of the foreign matter O, and then the door is operated.

In the foreign matter detection step, first, detection target point data at an arbitrary point in time when foreign matter detection is desired is acquired (step S11). In the case of performing real-time foreign matter detection, the range sensor 5 is operated at this time, and the measurement within the target area A may be performed. In the next steps S12 and S13, the detected point data acquired in step S11 and the reference data are compared. In step S<b>12 , the difference between both data is calculated for each range sensor 5 . As the reference data, for example, as described above, when the vehicle 1 is parked, the detected point data acquired when the vehicle 1 stops at the stop position P can be used (FIG. 2, steps S7 and S8). reference).

Processing such as downsampling and noise removal is performed on the difference data, and labeling processing is performed on the remaining detection point data (step S13). In this step S13, for example, among the detected point data remaining as a difference, if a plurality of detected points exist at coordinates close to each other, the detected points are labeled with the same label, and they are identified as the same foreign matter. Perform processing that is considered to belong to O.

In subsequent steps S14 to S16, as a result of the comparison performed in steps S12 and S13, it is determined whether or not a difference of a predetermined value or more is found between the data, and based on this, the detected point data is acquired in step S11. It is determined whether or not the foreign matter O exists in the target area A at the time point. In step S14, the number of foreign objects O is counted with respect to the labeled differential data of each range sensor 5. FIG. If one or more detection point data that are considered to be foreign matter O are recognized in the difference data in one or more range sensors 5, a detection flag is set (step S15), and the foreign matter detection process ends. If the difference data of any range sensor 5 does not contain detected point data that is considered to be foreign matter O, the foreign matter detection process ends without setting a detection flag (step S16).

If the detection flag is set in the above foreign matter detection process, for example, actions such as movement of the pallet 2 or opening/closing of the loading/unloading door 4 are stopped, or the operation is prohibited. Moreover, an alarm is issued from the alarm device 8 as needed. Then, for example, when it is confirmed by an attendant or the like that there is no foreign object O within the target area A and the alarm is canceled, the foreign object detection step is executed again. If the detection flag is raised by re-executing the foreign object detection process, the operation of the pallet 2, the loading/unloading port 4, etc. is kept prohibited, and if the detection flag is not raised, the prohibition of the operation is released.

According to such a foreign object detection system and method, a foreign object O in the target area A can be detected with a simple configuration in which the range sensor 5 is arranged in the target area A. Unlike the system that detects foreign matter on the floor like the technology described in Patent Document 1, the space is scanned by the irradiation wave of the range sensor 5, so foreign matter O on the pallet 2 can also be detected. is. Further, in detecting the presence of the foreign object O from the acquired detected point data, it is sufficient to directly compare the detected point data acquired at an arbitrary point in time with the reference data acquired at another point in time. In other words, unlike the techniques described in Patent Documents 2 and 3, there is no need for complicated calculations such as specifying the size of an object, calculating the position of the center of gravity, or obtaining vehicle contour data. The foreign object O can be detected by directly comparing the data, such as taking the difference between both data. Therefore, the foreign object detection can be performed by performing a very simple calculation, and high-speed and highly reliable detection is possible. .

Further, in the foreign object detection system of this embodiment, it is possible to determine whether the vehicle 1 is stopped as shown in FIG. In this way, the processes from the stop determination of the vehicle 1 to the detection of the foreign object O can be performed only by the foreign object detection system without separately installing a device or the like for the stop determination. For example, in the technique described in Patent Document 3, it is determined by a position sensor installed separately from the range sensor that the vehicle has stopped at a fixed position on the pallet. , acquisition of vehicle contour data is started. In such a system, it is conceivable that, for example, if some kind of malfunction occurs in the position sensor, foreign object detection cannot be executed. As in the present embodiment, in addition to the foreign matter detection process (see FIG. 3), if the same system is used to execute the stop determination process (see FIG. 2) of the vehicle 1, a separate Even if there is a problem with the installed device or the like, it will not hinder the proper execution of even the foreign matter detection process. In addition, as described above, it is possible to easily use detected point data obtained during the stop determination process, or before or after the process, in the foreign object detection process described later.

Here, as an example of the target area A, a loading/unloading space provided with only the pallet 2 as a device for transporting the vehicle 1 has been described, but the type of the target area A is not limited to this. For example, in a loading/unloading space having a turntable in front of a pallet, a system similar to the foreign matter detection system in the present disclosure can be provided on the turntable and its surroundings, and on the pallet and its surroundings, respectively. Alternatively, the present invention is not limited to mechanical parking lots, and can be widely applied to general facilities that perform some operations around vehicles, such as power supply facilities for electric vehicles.

As described above, in the foreign matter detection method of the present embodiment, the range sensor 5 for measuring the inside of the target region A into which the vehicle 1 enters is arranged with respect to the target region A, and the foreign matter O is detected in the target region A. Steps S7 and S8 for acquiring the detected point data as reference data by the range sensor 5 in a state where there is no sensor; Step S11 for acquiring the detected point data by the range sensor 5 at an arbitrary time; Steps S12 and S13 for comparing the acquired detection point data with the reference data, and if a difference of a predetermined value or more is found between the data in the steps S12 and S13, a foreign object is present in the target area A at the arbitrary time. A foreign matter detection process including steps S14 to S16 for determining that O exists is executed. In this way, a foreign object O within the target area A can be detected with a simple configuration in which the range sensor 5 is arranged with respect to the target area A. FIG. In detecting a foreign object, it is sufficient to perform a very simple operation on the data, and high-speed and highly reliable detection is possible.

In the foreign object detection method of this embodiment, the reference data can be detection point data acquired when the vehicle 1 enters the target area A and stops at the stop position P within the target area A.

In the foreign matter detection method of the present embodiment, in addition to the foreign matter detection step, as the vehicle 1 enters the target region A, the range sensor 5 is operated to measure the target region A from time to time. Steps S1 and S2, steps S3 and S4 for comparing detected point data acquired at the most recent time point with detected point data acquired at an earlier time point, and determining a difference between the detected point data at a predetermined value. When the following state continues for a predetermined time or longer, a vehicle stop determination process including steps S5 and S6 for determining that the vehicle 1 has stopped is executed. In this way, the movement and stopping of the vehicle 1 in the target area A can be smoothly coordinated with various operations around the vehicle 1 .

In the foreign object detection method of the present embodiment, as the reference data, in the stop determination step of the vehicle 1, the state in which the difference between the detected point data is equal to or less than a predetermined value continues immediately before the vehicle 1 is determined to be stopped. It is possible to use detected point data acquired during the operation or detected point data acquired immediately after it is determined that the vehicle 1 has stopped in the vehicle 1 stop determination step.

Further, the foreign object detection system of this embodiment is provided with a range sensor 5 for measuring the target area A into which the vehicle 1 is entering. is acquired as reference data, the detected point data is acquired by the range sensor 5 at an arbitrary time, the detected point data acquired at the arbitrary time is compared with the reference data, and a predetermined or more data is obtained between the data It is configured to determine that the foreign matter O is present in the target area A at the arbitrary point in time when the difference is found. In this way, the foreign matter O within the target area A can be detected favorably with a simple configuration in which the range sensor 5 is arranged with respect to the target area A. FIG.

In the foreign object detection system of this embodiment, two or more range sensors 5 are installed in the target area A, and are arranged so that the measurement range includes the entire circumference of the stop position P of the vehicle 1 in plan view. Therefore, foreign object detection can be performed for the entire area around the vehicle 1 without omission.

Therefore, according to the present embodiment, it is possible to easily detect a foreign object in the target area.

The foreign matter detection method and system of the present invention described in the present disclosure are not limited to the above-described embodiments, and can of course be modified in various ways without departing from the scope of the invention.

REFERENCE SIGNS LIST 1 vehicle 2 pallet 3 transport port 4 loading/unloading port 5 range sensor 5a measurement signal 6 control device 7 warehousing switch 7a warehousing signal 8 alarm device 8a alarm signal A target region O object (foreign matter)
P stop position

Claims (6)

A range sensor for measuring the target area into which the vehicle enters is arranged with respect to the target area,
a step of obtaining detected point data as reference data by the range sensor in a state where the vehicle is stopped at a stop position of the target area and there is no foreign object in the target area;
a step of acquiring detected point data by the range sensor at an arbitrary point in time when the vehicle is stopped at a stop position in the target area ;
a step of comparing the detected point data including the detected points in the area where the vehicle has stopped , acquired at the arbitrary time, with the reference data including the detected points in the area where the vehicle has stopped ;
and determining that a foreign object exists in the target area at the arbitrary point in time when a difference of a predetermined value or more is found between the data in the step. 2. The foreign object detection method according to claim 1, wherein said reference data is detected point data acquired when a vehicle enters a target area and stops at a stop position within the target area. In addition to the foreign matter detection step,
a step of actuating the range sensor to measure the target area from time to time as the vehicle enters the target area;
a step of comparing detected point data acquired at the most recent time point with detected point data acquired at an earlier time point;
3. The vehicle stop determination step of determining that the vehicle has stopped when a state in which the difference between the detected point data is equal to or less than a predetermined value continues for a predetermined time or longer. foreign object detection method. As the reference data,
In the vehicle stop determination step, the detected point data acquired while the state in which the difference between the detected point data is equal to or less than a predetermined value continues immediately before it is determined that the vehicle is stopped; or
4. The foreign matter detection method according to claim 3, wherein, in said vehicle stop determination step, detected point data acquired immediately after it is determined that the vehicle has stopped is used. Equipped with a range sensor that measures the target area into which the vehicle enters,
While the vehicle is stopped at the stop position of the target area and there is no foreign object in the target area, data of the point to be detected is acquired as reference data by the range sensor, and
Acquiring detected point data by the range sensor at an arbitrary time when the vehicle is stopped at the stop position of the target area ,
The detected point data including the detected points in the stopped area of the vehicle acquired at the arbitrary time is compared with the reference data including the detected points in the stopped area of the vehicle, and a difference of a predetermined value or more exists between the data. A foreign object detection system configured to determine, if seen, that a foreign object is present in the region of interest at the given time. 6. The foreign object detection system according to claim 5, wherein two or more of said range sensors are installed with respect to the target area, and arranged so that the measurement range includes the entire circumference of the stop position of the vehicle in plan view.

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