JP2020067437A - Foreign matter detection method and system - Google Patents

Abstract

To provide a foreign matter detection method and system with which it is possible to detect foreign matter in a target area easily.SOLUTION: With a 3D scanner 5 for measuring the inside of a target area A which a vehicle 1 enters provided, the foreign matter detection method includes: acquiring detected point data by the 3D scanner 5 as reference data while there is no foreign matter inside of the target area A; acquiring detected point data by the 3D scanner 5 at a discretionary point of time; comparing the detected point data acquired at the discretionary point of time with the reference data; and determining that a foreign matter O exists inside of the target area A at the discretionary point of time when a difference greater than or equal to a prescribed difference is found between the data.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method and system for detecting foreign matter other than a vehicle in a region where the vehicle stops such as a parking lot.

  In a space where a vehicle enters and stops, such as an entry / exit space of a mechanical parking lot, when performing operations such as opening / closing the door of an entrance / exit and carrying a pallet carrying a vehicle, the driver in addition to the vehicle It is necessary to make sure that there are no foreign objects such as passengers, passengers and baggage. The operation of confirming the absence of foreign matter can be visually performed by a driver or a staff member of a facility, but if relying only on human power, the confirmation may not be thorough due to carelessness. Therefore, in recent years, there has been a demand for a technique of automatically detecting a foreign substance in a target area without relying only on human power so as to reliably confirm the absence of the foreign substance.

  Further, if the autonomous driving technology currently being developed in each country is put into full-scale practical use, not only the operation of the vehicle but also various operations performed around the vehicle such as opening and closing the doors and transporting pallets as described above. It can be assumed that the automation of the operation will proceed. For example, there is a case where the vehicle automatically sends the occupant to the destination and then automatically moves to a nearby mechanical parking lot and is stored in the storage space.In this case, the vehicle does not have an occupant. It will move in the state and stop in the storage space. At this time, operations such as opening and closing the door and starting the movement of the pallet may be performed by an operator visually confirming the absence of foreign matter and pressing an operation button, but the absence of foreign matter is automatically detected. 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 operation is performed around a stopped vehicle, such as a power supply facility for an electric vehicle.

  As a technique for automatically detecting a foreign matter in a target area into which a vehicle enters, for example, a technique described in Patent Document 1 below can be cited. Patent Document 1 describes a technique for detecting the presence of a person by laying a mat switch composed of a piezoelectric sheet on the entire floor surface of an external communication part 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 substance in a pallet or the like on which a mat switch is not installed.

  Therefore, as a technique capable of detecting a foreign substance in a region other than the region where a mat switch or the like can be laid, for example, techniques described in Patent Documents 2 and 3 below have been proposed. Patent Document 2 describes a storage section detection device that includes a range sensor in a storage section of a mechanical parking facility and detects an object on a floor surface from scanning information of the range sensor. In the warehousing unit detection device, of the detection data of the range sensor, data of a predetermined size or more is used as candidate data, and the data other than the one recognized as the tire of the automobile is recognized as a residue.

  Patent Document 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 the vehicle that has entered the entry / exit area of the mechanical parking facility, and acquires vehicle contour data. The control device stores the state of the residence detection range excluding the range of the vehicle contour data in the entry / exit area as initial storage data, and compares it with real-time data to determine whether there is a difference.

Japanese Patent Laid-Open No. 06-173483 JP, 2005-161080, A JP, 2014-80735, A

  However, in the techniques described in Patent Documents 2 and 3, it is required to perform high-level arithmetic processing on data when detecting a foreign substance. In the case of the warehousing unit detection device described in Patent Document 2, first, an object having a predetermined size or more is selected from the detection data as candidate data, and the candidate data having a closer center of gravity is associated as the same object and recognized as a tire. . A complicated calculation is required in the process of detecting the size of the object from the detection data and identifying and correlating 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 contour of the vehicle is acquired based on the scanning by the range sensor. In most cases, the surface of a vehicle has a complicated shape, and in order to create the vehicle contour data from the data of the range sensor, a complicated calculation is still necessary.

  As described above, a technique for automatically detecting a foreign matter generally requires a high degree of calculation. For this reason, there is a possibility that smooth operation may be hindered, for example, it takes time to calculate data when entering and leaving a mechanical parking facility.

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

  In the present disclosure, a range sensor for measuring the inside of a target area into which a vehicle enters is arranged with respect to the target area, and in the state where there is no foreign matter in the target area, the detected point data is acquired as reference data by the range sensor. And the step of acquiring the detected point data by the range sensor at an arbitrary time point, the step of comparing the detected point data acquired at the arbitrary time point with the reference data, and between the data in the step. The present invention relates to a foreign matter detection method for performing a foreign matter detection process including a step of determining that a foreign matter is present in the target area at the arbitrary time when a difference of a predetermined value or more is found.

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

  In the foreign matter detection method described above, in addition to the foreign matter detection step, a step of activating the range sensor to measure the inside of the target area momentarily as the vehicle enters the target area, and the latest time point The step of comparing the detected point data acquired in step 1 with the detected point data acquired at a previous time point, and the state where the difference between the detected point data is less than or equal to a predetermined value continues for a predetermined time or more. In addition, a vehicle stop determination process including a step of determining that the vehicle has stopped may be executed.

  In the foreign matter detection method described above, as the reference data, in the vehicle stop determination step, the state where the difference between the detected point data is less than or equal to a predetermined value immediately before the vehicle stop determination is being continued. It is possible to use the detected point data acquired in step 1) or the detected point data acquired immediately after the vehicle stop is determined in the vehicle stop determination step.

  Further, the present disclosure includes a range sensor for measuring the inside of a target area into which a vehicle enters, and the detected point data is acquired as reference data by the range sensor in a state where there is no foreign object in the target area. At the time point, the detected point data is acquired by the range sensor, and the detected point data acquired at the arbitrary time point is compared with the reference data. The present invention relates to a foreign matter detection system configured to determine that a foreign matter is present in the target area at the time.

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

  According to the foreign matter detection method and system of the present invention, the excellent effect that foreign matter in the target area can be detected easily can be obtained.

FIG. 1 is a schematic plan view illustrating an overall configuration of a foreign matter detection system according to an example of the present disclosure. 6 is a flowchart illustrating an example of a procedure of vehicle stop determination in the present embodiment. It is a flow chart explaining an example of a procedure of a foreign substance detection process in this example.

  Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The foreign matter detection system of the present embodiment shown in FIG. 1 assumes a storage space for mechanical parking equipment as the target area A. A pallet 2 that carries the vehicle 1 enters and leaves the target area A, and an area on the pallet 2 is set as a stop position P of the vehicle 1. Then, when an object (foreign matter) O exists in the target area A other than the vehicle 1 stopped at the stop position P, the foreign matter O is detected. Incidentally, the "foreign object" is an object other than the vehicle existing in the target area, an object other than the object originally installed in the target area, for example, a driver of the vehicle, an occupant, a person in charge of equipment, etc., It also refers to baggage, etc. In FIG. 1, two foreign matters O are shown in the target area A as an example.

  The target area A, which is a loading / unloading space, is a space surrounded by walls on all sides, with the transport port 3 on the back side (upper side in the drawing) and the loading / unloading port 4 on the front side (lower side in the drawing). ing. The pallet 2 that transports the vehicle 1 enters and leaves the storage area (not shown) outside the target area A through the transfer port 3 into and out of the target area A that is a storage space. The fixed position of the pallet 2 in the target area A is the central portion of the target area A. At the time of loading, the vehicle 1 enters the target area A through the loading / unloading port 4, stops at the stop position P on the pallet 2, and is transported together with the pallet 2 from the transport port 3 to the storage space and stored. At the time of leaving the warehouse, the vehicle 1 is transported together with the pallet 2 from the storage space into the target area A through the transport port 3, and then exits from the target area A through the loading / unloading port 4.

  In the target area A, a range sensor 5 for measuring the target area A is arranged. As shown by the arrow in FIG. 1, the range sensor 5 is a device that irradiates the surrounding space with laser light, ultrasonic waves, or the like as an irradiation wave and detects a reflected wave. When the irradiation wave from the range sensor 5 reaches and is reflected by a surrounding object or a structure such as a wall, a floor, or a column, and the reflected wave is detected by the range sensor 5, the range sensor at the reflected point is detected. The distance from 5 and the angle with respect to the range sensor 5 are acquired as data (hereinafter, the point in the target area A where the reflected wave is detected by the range sensor 5 is referred to as a detected point).

  In this embodiment, the two range sensors 5 are arranged at the corners that are diagonal to each other with respect to the target area A having a rectangular shape in plan view. Thus, by disposing 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 plan view can be included in the measurement range of the range sensor 5. . Since the irradiation wave travels straight in principle, if only one range sensor 5 is arranged in the target area A, the measurement range will be measured on the opposite side of the vehicle 1 stopped at the stop position P when viewed from the range sensor 5. It will be outside. Therefore, by disposing the range finding sensor 5 as shown in FIG. 1, it is possible to detect a foreign substance in the entire area around the vehicle 1 without omission. Note that the number and arrangement of the range sensors 5 shown here are merely examples, and three or more range sensors 5 are arranged in the target area A in order to improve measurement accuracy and secure a wide measurable range. You may arrange it to face.

  The data of each detected point (hereinafter referred to as “detected point data”) acquired by the range sensor 5 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 that is a loading / unloading space and operates each part, and opens / closes the transport port 3 and the loading / unloading port 4, transports the pallet 2, The operation of the range sensor 5 is controlled.

  A warehousing switch 7 is provided on the outer wall near the warehousing / unloading port 4. When the warehousing switch 7 is operated, the warehousing signal 7a is input to the control device 6. In the control device 6, on condition that the warehousing signal 7a is input, each process relating to the warehousing of the vehicle 1, that is, the transportation of the pallet 2, the opening of the warehousing / unloading port 4, the process of the stop determination described later, and the like 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 warehousing / discharging port 4 can be selected.

  Further, alarm devices 8 are provided at various locations inside and outside the target area A. The alarm device 8 is a device that issues an alarm in the area managed by the control device 6 (including the target area A) when any situation that requires attention to personnel occurs, and an alarm signal from the control device 6 is issued. It operates by the input of 8a. “Something that requires attention to personnel” means, for example, when moving the vehicle 1 to a storage space outside the target area A, as a result of executing a foreign matter detection process described later, the target area A For example, when the foreign matter O is detected. The content of the alarm may be any sound, such as an alarm sound, lighting of a warning light, and display of a warning message, as long as the personnel can be alerted, 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 in the vicinity of the loading / unloading port 4, but the alarm device 8 may be provided at other places as necessary. . For example, the alarm device 8 may be provided in a management room or the like of a mechanical parking lot (not shown).

  The 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 format. As an example, the control device 6 and the range sensor 5, the warehousing switch 7, and the alarm device 8 may be connected to each other by Ethernet (registered trademark) or the like, and may be configured to communicate with each other.

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

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

  The stop determination is performed by the control device 6 on condition that the warehousing signal 7a is input. In the example shown here, the entry signal 7a is input by operating the entry switch 7. That is, when the vehicle 1 stops before the loading / unloading port 4, the driver of the vehicle 1 or an occupant who is an attendant of a mechanical parking lot operates the loading switch 7 to input the loading signal 7a. is there. However, this is merely an example, and the input of the warehousing signal 7a may be performed by another method. For example, when the vehicle 1 that is an automatic driving vehicle is unmanned and moves to the front of the entry / exit opening 4 of the target area A that is the entry / exit space, and automatically enters, there is also a situation in which there is no personnel who operates the entry switch 7. is assumed. In such a case, for example, a sensor for detecting the vehicle 1 in front of the loading / unloading port 4 may be separately provided, and when the vehicle 1 is detected by the sensor, the detection signal may be treated as a loading / unloading signal. Alternatively, some signal may be output from the vehicle 1 and the control device 6 may recognize the signal as a warehousing signal.

  When the warehousing signal 7a is input, the control device 6 opens the warehousing / unloading port 4. At the start of warehousing, the warehousing / unloading port 4 is opened in a state where the empty pallet 2 is arranged in the central portion which is a fixed position in the target area A. If there is no empty pallet 2 in the target area A at the time when the start of warehousing is instructed, the transfer port 3 is opened to transfer the empty pallet 2 to the target area A, and the pallet 2 is placed in the central portion. After that, the loading / unloading port 4 is opened. Then, the stop determination process shown in FIG. 2 is started.

  When the loading / unloading port 4 is opened, the vehicle 1 moves toward the pallet 2 in the target area A during the slow driving. In the control device 6, each range sensor 5 is operated, and each range sensor 5 measures the target area A (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 at which the radiated wave is reflected on the structure or object surface in 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 measurement in the target area A is performed by the range sensor 5 as in step S1. After step S1, the measurement in step S2 is repeatedly executed every 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 preceding step S1. In step S3, the difference between both data is calculated. The difference data is calculated for each of the range sensors 5 with respect to the acquired detected point data. Then, after performing processing such as downsampling and noise removal, in the next step S4, it is determined whether or not the number of detected points remaining in the difference data is less than the threshold value for each range sensor 5.

  When there is no difference in the presence, 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 detected point data is matched unless noise or the like is taken into consideration. That is, since the difference between the detected point data at both time points is zero, no detected point remains in the difference data. On the other hand, when the object moves within the target area A, the detected point data has a difference between both time points, so that the detected point remains in the difference data. That is, in step S4, it is determined whether or not the detected point data before and after measured by each range sensor 5 has a difference equal to or more than a predetermined value, and thus whether or not there is a movement in the target area A is determined. Make a decision. Of course, the movement in the target area A assumed here is the movement of the vehicle 1 to the stop position P.

  When the number of detected points remaining in the difference data is equal to or larger than the threshold value in one or more range sensors 5, the process returns from step S4 to step S2, and the range sensor 5 performs the measurement again. Then, the detected point data acquired here is compared with the previously acquired detected point data in steps S3 and S4. That is, in step S3, the difference between the detected point data acquired in the immediately preceding step S2 and the detected point data acquired in the preceding step S2 is calculated, and the difference data is determined in subsequent step S4. These steps S2 to S4 are repeated until the number of detected points remaining in the difference data becomes less than the threshold value. It is considered that the vehicle 1 is moving without stopping while the number of detected points equal to or more than the threshold remains in the difference data. Therefore, the detected points remaining in the difference data are less than the threshold and the vehicle 1 remains stationary. The measurement is repeated until it can be determined that it has been done.

  When it is determined in step S4 that the number of detected points remaining in the difference data calculated in the immediately preceding step S3 is less than the threshold value in all the range sensors 5, the process proceeds to step S5. In step S5, the state determined to be 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 in all the range sensors 5" has continued for a predetermined time or more. Determine whether or not. That is, the duration of the state in which the difference between the detected point data acquired in the latest step S2 and the step S2 or step S1 before that is less than or equal to a predetermined value is determined.

  If the duration of this state is less than the predetermined value, the process returns to step S2 again, and steps S2 to S5 are repeated until the duration of the state becomes the predetermined time or more. Then, when it is determined in step S5 that the duration of the state is equal to or greater 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 may be possible to temporarily stop and restart the movement in the middle, so that the vehicle 1 remains stationary for a certain period of time or longer. That is, it is determined that the vehicle 1 has definitely stopped at the target stop position P.

  Although the stop determination itself is completed up to step S6, in the present embodiment, the detected point data used in the subsequent foreign substance detection step (see FIG. 3) is acquired subsequently. 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 operated, and the detected point data at the time immediately after it is determined that the vehicle 1 has stopped is acquired. In step S8, the detected point data acquired in step S7 is stored as reference data when the vehicle 1 is stopped, and the process ends.

  It should be noted that here, step S1 is executed as a step of acquiring the first detected point data before repeating steps S2 to S3, but this step S1 is not always necessary. For example, step S1 may be omitted, and in the first step S3 in the stop determination process, the detected point data acquired in the immediately preceding step S2 may be compared with the Null data. In that case, the difference data calculated in the first step S3 always becomes the detected point data equal to or more than the threshold value, and it is determined that the vehicle 1 is moving, so there is no particular problem in the stop determination.

  Further, the timing of acquiring the detected point data used as the reference data is not limited to the example described here. If the vehicle 1 is stopped at the stop position P in the target area A and the detected point data is acquired by the range sensor 5 in a state in which it is considered that the foreign matter O does not exist in the target area A, the reference It can be used as data. For example, in the stop determination process of the vehicle 1 shown in FIG. 2, immediately before the stop of the vehicle 1 is determined in step S5, while the state in which the difference between the detected point data is less than or equal to a predetermined value continues, step S2 The detected point data acquired in step 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 is equal to or more than the predetermined value, but during this period, the determination in step S4 is YES. Is continuing. That is, the detected point data acquired in step S2 during this period is “the detected point in a state where the vehicle 1 is stopped at the stop position P in the target area A and the foreign object O is not present in 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 continues until the determination in step S5 is stored as reference data. Of. Even in this case, it is considered that “the detected point data when the vehicle 1 stops at the stop position P in the target area A” is “obtained in the state where there is no foreign object O in the target area A”. The detected point data that can be obtained can be acquired as reference data.

  In addition, although the case where the present system for detecting a foreign object as shown in FIG. 1 is used for the stop determination of the vehicle 1 is illustrated here, the foreign object detecting system according to the present disclosure is not necessarily installed in a mechanical parking lot or the like. It is not necessary for the system to have the functions of both stop determination and foreign matter detection. The foreign matter detection process described below is performed by the system as shown in FIG. 1, while the stop determination may be performed by separately installing a sensor or the like for detecting the position of the vehicle 1 with respect to the pallet 2. However, in order to smoothly coordinate the movement and stop of the vehicle 1 in the target area A and various operations around the vehicle 1, the vehicle 1 is stopped by the system for detecting a foreign object as in the present embodiment. It is more advantageous to be able to determine even in terms of simplifying the system configuration and speeding up the operation. Alternatively, a plurality of systems may be used in combination, such that a system such as that of the present embodiment makes a stop determination and a stop sensor is also used to make a stop determination.

  Next, the foreign matter detecting step will be described with reference to FIG.

  The foreign substance detection process can be started at any timing when it is desired to check the state in the target area A. For example, when there is a driver or an occupant in the vehicle 1 at the time of warehousing, or an attendant is in the target area A, after the vehicle 1 is stopped at the stop position P, the transportation of the vehicle 1 by the pallet 2 is started. It can be assumed that it is necessary to confirm before that the target area A is unattended. In that case, the foreign matter detection step may be automatically started immediately after the series of steps shown in FIG. 2 is completed, and the movement of the pallet 2 may be executed on the condition that the foreign matter O is not detected. Alternatively, the foreign matter detection step may be started at the time when the transportation of the vehicle 1 is instructed by the operation of a switch or the like (not shown), the transportation is performed when the foreign matter O is not detected, and the transportation is stopped when the foreign matter O is detected. good. In addition, when closing the loading / unloading port 4, it is possible to assume a mode in which the foreign material detection step is executed to confirm the absence of the foreign material O before the door is operated.

  In the foreign matter detection step, first, detected point data at an arbitrary time point at which foreign matter detection is desired is acquired (step S11). When performing real-time foreign matter detection, the range sensor 5 may be operated at this point to measure the inside of the target area A. In the next steps S12 and S13, the detected point data acquired in step S11 is compared with the reference data. In step S12, the difference between both data is calculated for each range sensor 5. As the reference data, for example, as described above, it is possible to use the detected point data acquired when the vehicle 1 is parked and the vehicle 1 is stopped at the stop position P (FIG. 2, steps S7 and S8). reference).

  Processing such as downsampling or noise removal is performed on the difference data, and labeling processing is performed on the remaining detected point data (step S13). In this step S13, for example, if a plurality of detected points exist in the coordinates close to each other among the detected point data remaining as the difference, the detected points are marked with the same mark, and they are the same foreign matter. Perform processing that is regarded as belonging to O.

  In subsequent steps S14 to S16, it is determined whether or not there is a predetermined difference or more between the data as a result of the comparison performed in steps S12 and S13, and based on this, the detected point data is acquired in step S11. It is determined whether or not the foreign matter O is present in the target area A at the time point. In step S14, the number of foreign matters O is counted in the labeled difference data of each range sensor 5. When one or more range sensors 5 detect one or more foreign object O detected point data in the difference data, a detection flag is set (step S15), and the foreign object detection process ends. If there is no detected point data that is considered to be foreign matter O in the difference data of any of the range sensors 5, the detection flag is not set (step S16), and the foreign matter detection process ends.

  When the detection flag is set in the above foreign substance detection process, actions such as stopping the operation of moving the pallet 2 or opening / closing the loading / unloading port 4, or prohibiting the operation are performed. Further, an alarm is issued from the alarm device 8 as needed. Then, for example, when a staff member or the like confirms that there is no foreign matter O in the target area A and the alarm is released, the above foreign matter detection step is executed again. When the foreign substance detection process is re-executed and the detection flag is raised, the operation of the pallet 2, the loading / unloading port 4, etc. is kept prohibited, and when the detection flag is not raised, the prohibition of the operation may be released.

  According to such a foreign matter detection system and method, the foreign matter O in the target area A can be detected with a simple configuration in which the range finding sensor 5 is arranged in the target area A. Unlike the system for detecting a foreign substance on the floor surface as in the technique described in Patent Document 1, the space is scanned by the irradiation wave of the range sensor 5, so that the foreign substance O on the pallet 2 can also be detected. Is. Further, in detecting the presence of the foreign matter O from the acquired detected point data, it suffices to directly compare the detected point data acquired at an arbitrary time point with the reference data acquired at another time point. That is, unlike the techniques described in Patent Documents 2 and 3, complicated calculations such as specifying the size of an object, calculating the position of the center of gravity, or acquiring vehicle contour data are not required. Since the foreign matter O can be detected by directly comparing the data, such as taking the difference between the two data, a very simple calculation can be performed to detect the foreign matter, and high-speed and highly reliable detection is possible. .

  In addition, the foreign matter detection system of this embodiment can also determine whether the vehicle 1 is stopped as shown in FIG. By doing so, the steps from the stop determination of the vehicle 1 to the detection of the foreign matter O can be performed only by the foreign matter 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 that the vehicle has stopped at a fixed position on the pallet by a position sensor installed separately from the range sensor, and a trigger signal is transmitted on the condition. The acquisition of vehicle contour data is started. In such a system, it is conceivable that the foreign matter detection cannot be executed, for example, when some trouble occurs in the position sensor. As in the present embodiment, if the vehicle 1 stop determination step (see FIG. 2) is executed by the same system in addition to the foreign matter detection step (see FIG. 3), the vehicle 1 stop determination will be performed separately. Even if the installed device or the like has a problem, the problem does not prevent the foreign matter detection step from being properly performed. Further, for example, as described above, it is possible to easily use the detected point data acquired during the process of the stop determination or before and after the process for the foreign substance detection process described later.

  In addition, here, as an example of the target area A, the storage space including only the pallet 2 as the device for transporting the vehicle 1 has been described, but the format of the target area A is not limited to this. For example, in a loading / unloading space of a type having a turntable in front of a pallet, the turntable and its periphery and the pallet and its periphery can be provided with systems similar to the foreign matter detection system of the present disclosure. Alternatively, the invention is not limited to the mechanical parking lot, and can be widely applied to general equipment that performs some operation around the vehicle, such as power feeding equipment 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 area A into which the vehicle 1 enters is arranged with respect to the target area A, and the foreign matter O in the target area A is detected. In the state where there is no data, steps S7 and S8 for acquiring the detected point data as reference data by the range sensor 5, step S11 for acquiring the detected point data by the range sensor 5 at an arbitrary time, and When a difference of a predetermined value or more is found between the data in steps S12 and S13 for comparing the acquired detected point data with the reference data and the data in steps S12 and S13, the foreign matter is present in the target area A at the arbitrary time point. The foreign substance detection step including steps S14 to S16 for determining that O is present is executed. With this configuration, the foreign matter 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. When detecting a foreign substance, a very simple calculation may be performed on the data, and high-speed and highly reliable detection is possible.

  In the foreign matter detecting method according to the present embodiment, the reference data may be detected point data acquired when the vehicle 1 enters the target area A and stops at the stop position P in the target area A.

  In the foreign matter detecting method of the present embodiment, in addition to the foreign matter detecting step, a step of operating the range sensor 5 to perform measurement in the target area A every moment as the vehicle 1 enters the target area A. S1 and S2, steps S3 and S4 of comparing the detected point data acquired at the latest time point with the detected point data acquired at the previous time point, and the difference between the detected point data is a predetermined value. When the following state continues for a predetermined time or more, the vehicle stop determination process including steps S5 and S6 for determining that the vehicle 1 has stopped is executed. By doing so, the movement or stop of the vehicle 1 in the target area A and various operations around the vehicle 1 can be smoothly linked.

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

  Further, the foreign matter detection system of this embodiment includes a range sensor 5 for measuring the inside of the target area A into which the vehicle 1 enters, and the range sensor 5 detects the detected point data in a state where there is no foreign object O in the target area A. Is obtained as reference data, the detection point data is obtained by the range sensor 5 at an arbitrary time point, the detected point data obtained at the arbitrary time point is compared with the reference data, and a predetermined value or more is kept between the data. When a difference is found, it is configured to determine that the foreign matter O is present in the target area A at the arbitrary time point. By doing so, the foreign matter O in the target area A can be preferably detected with a simple configuration in which the range sensor 5 is arranged in the target area A.

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

  Therefore, according to the present embodiment, the foreign matter in the target area can be easily detected.

  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 it goes without saying that various modifications can be made without departing from the scope of the invention.

1 Vehicle 2 Pallet 3 Transfer Port 4 Entry / Exit Port 5 Measuring Range Sensor 5a Measurement Signal 6 Control Device 7 Entry Switch 7a Entry Signal 8 Alarm Device 8a Alarm Signal A Target Area O Object (Foreign Object)
P stop position

Claims (6)

A range sensor that measures the inside of the target area where the vehicle enters is arranged for the target area,
A step of acquiring the detected point data as reference data by the range sensor in a state where there is no foreign matter in the target area,
Acquiring the detected point data by the range sensor at any time,
Comparing the detected point data acquired at the arbitrary time point with the reference data,
A foreign matter detection method, comprising: a step of determining that a foreign matter is present in the target area at the arbitrary time point when a difference of a predetermined value or more is found between the data in the step.   The foreign matter detection method according to claim 1, wherein the reference data is detected point data acquired when a vehicle enters the target area and stops at a stop position in the target area. In addition to the foreign matter detection step,
With the entry of the vehicle into the target area, the step of operating the range sensor to perform the measurement in the target area every moment,
A step of comparing the detected point data acquired at the latest time point with the detected point data acquired at the previous time point,
The vehicle stop determination process including a 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 more, is executed. Foreign matter detection method. As the reference data,
In the vehicle stop determination step, the detected point data obtained while the state in which the difference between the detected point data is equal to or less than a predetermined value immediately before the vehicle is determined to be stopped, or
The foreign matter detection method according to claim 3, wherein in the vehicle stop determination step, the detected point data acquired immediately after the vehicle stop is determined is used. Equipped with a range sensor that measures the inside of the target area where the vehicle enters,
While acquiring the detected point data as reference data by the range sensor in the state where there is no foreign matter in the target area,
Acquire the detected point data by the range sensor at any time,
The detection point data acquired at the arbitrary time is compared with the reference data, and when a difference of a predetermined value or more is found between the data, it is determined that a foreign substance is present in the target area at the arbitrary time. Foreign matter detection system.   The foreign matter detection system according to claim 5, wherein two or more range finding sensors are installed in the target area, and are arranged such that the entire circumference of the vehicle stop position is included in the measurement range in plan view.

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