JP2020067436A - 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 a nearest point from the detected point data of the 3D scanner 5 while the vehicle 1 stays still at a stop position P inside of the target area A; setting a detection exclude area on the basis of the nearest point; and detecting foreign matter on the basis of the detected point data having been detected in an area other than the detection exclude area out of the target area A. The 3D scanner 5 is arranged in pairs at least at positions diagonally forward and diagonally rearward of the stop position P so as to face across the vehicle 1 that stops at the stop position P, and the detection exclude area is set on the basis of a rectangle the diagonal of which is composed of line segments linking together the nearest points acquired by the pair of 3D scanners 5.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 a 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 when the vehicle is stopped at a stop position in the target area, the detected point data is detected by the range sensor. Obtaining step, a step of setting a detection exclusion area based on the nearest point measured in each of the range sensors, based on the detected point data detected in the area other than the detection exclusion area, of the target area And a foreign matter detection method.

  In the foreign matter detection method described above, the range sensor is arranged at a position diagonally forward and diagonally rearward of the stop position so as to face each other with the vehicle stopped at the stop position interposed therebetween, and the detection exclusion area is It can be set based on a rectangle whose diagonal is a line segment connecting the closest points acquired by the pair of range sensors.

  In the above-described foreign matter detection method, in the step of comparing the detected point data acquired at the arbitrary time point with the reference data, the data related to the detected points having the reference height or less from the floor surface can be used for comparison. .

  In the foreign matter detection method described above, the detected point data acquired when the vehicle enters the target area and stops at the stop position can be used for setting the detection exclusion area.

  In the foreign matter detection method described above, the step of performing the foreign matter detection includes the step of acquiring the detected point data as reference data by the range finding sensor in a state where there is no foreign matter in the target area, and the range finding at any time point. A step of acquiring detected point data by a sensor, a step of comparing the detected point data acquired at the arbitrary time point with the reference data, and in the step, in regard to an area other than the detection exclusion area, And a step of determining that a foreign substance is present in the target area at the arbitrary time point when a difference of a predetermined value or more is observed.

  In the foreign matter detection method described above, the reference data is acquired when the vehicle enters the target area and stops at the stop position, or when there is no foreign object in the target area and there is no vehicle at the stop position. The detected point data can be used.

  In addition, the present disclosure includes a range sensor that measures the inside of a target area into which a vehicle enters, and a control device that processes detected point data of the range sensor. In the state of stopping at the stop position, the nearest point is acquired from the detected point data of the range sensor, the detection exclusion area is set based on the nearest point, and the area other than the detection exclusion area is set in the target area. The present invention relates to a foreign matter detection system configured to perform foreign matter detection based on detected detected point data.

  In the foreign matter detection system described above, at least one pair of the range sensors are arranged at diagonally forward and diagonally rearward positions of the stop position so as to face each other with the vehicle stopped at the stop position interposed therebetween, and the detection exclusion region is It can be configured to be set based on a rectangle having a diagonal line connecting the nearest points acquired by the pair of range sensors.

  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. It is a schematic plan view explaining the setting method of the detection exclusion area based on the closest point. 9 is a flowchart illustrating an example of a procedure of setting a detection exclusion area. It is a flow chart explaining an example of a procedure of a foreign substance detection process.

  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, for example, as shown in FIG. 1, two range-finding sensors 5a and 5b are arranged at diagonal corners of a target area A having a rectangular shape in plan view. Thus, by disposing the pair of range sensors 5a and 5b so as to sandwich the stop position P of the vehicle 1, the entire circumference of the stop position P in plan view is included in the measurement range of the range sensor 5. You can 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 sensors 5a and 5b as shown in FIG. 1, it is possible to detect foreign matter in the entire area around the vehicle 1 without omission.

  The reason why the pair of range sensors 5a and 5b are arranged in this way is also suitable for setting the detection exclusion area A0 (see FIG. 2) described later. The detection exclusion area A0 is an area set as an area occupied by the vehicle 1 stopped at the stop position P, and an area other than the detection exclusion area A0 is treated as a foreign object detection target, as described later.

  In this embodiment, the detection exclusion area A0 is set as a rectangular area. The vehicle 1 usually has a complicated shape composed of a large number of curved surfaces, but if it is a passenger car or the like, it has a shape that is almost a rectangle in a plan view, and the position of the vehicle 1 in a mechanical parking lot or the like can be determined. From the viewpoint of management, it can be regarded as a rectangle. Therefore, in the present embodiment, the shape of the vehicle 1 in plan view is regarded as a substantially quadrangle or a rectangle, and the detection exclusion area A0 is set based on the quadrangle or the rectangle.

  When the shape of the vehicle 1 in a plan view is regarded as a quadrangle, the position of its apex is calculated from the data of the detected point (hereinafter, referred to as “detected point data”) acquired by the range sensor 5 as described below. Can be calculated. Therefore, the range sensors 5 are arranged so as to face each other across the vehicle 1 stopped at the stop position P so that the pair of vertices forming a diagonal line of the vehicle 1 stopped at the stop position P are included in the measurement range. That is, of the pair of range sensors 5a and 5b, one range sensor 5a is disposed diagonally forward of the stop position P, and the other range sensor 5b is diagonally rearward of the stop position P, and the vehicle 1 is sandwiched. It is arranged at a position opposite to the area sensor 5a. In this way, the detected point detected closest to each of the range sensors 5 can be considered as a pair of vertices forming a diagonal line of the vehicle 1 (hereinafter, “each range sensor 5 Of the detected point data detected at the position corresponding to the vehicle 1, the detection point closest to the range sensor 5 is referred to as the closest point N. See FIG. Then, a quadrangle having a line segment connecting the pair of closest points N as a diagonal line is hypothesized, and the detection exclusion area A0 is set based on the quadrangle.

  As described above, a passenger car or the like handled in a mechanical parking lot or the like has a substantially rectangular shape in a plan view, so that a rectangular shape is preferable as a quadrangle shape assumed from a line segment connecting a pair of closest points N. . Here, in order to uniquely specify a rectangular shape from one diagonal line, it is necessary to further determine the aspect ratio or angle of the rectangle.

  The ratio of the length to the width of the vehicle falls within a generally fixed range if the vehicle is widely and generally used. Therefore, when the coordinates of the pair of closest points N are acquired, assuming that a rectangle having the pair of closest points N as opposite vertices and the aspect ratio being a predetermined value set for convenience, the range occupied by the vehicle 1 is assumed. You can set a rectangle that roughly matches. When it is desired to set a quadrangle with a higher degree of coincidence, for example, a method of narrowing down the vehicle type from the distance between the closest points N and setting a rectangle using an aspect ratio according to the vehicle type can be considered.

  When the shape of the pallet 2 or the positional relationship between the stop position P and the loading / unloading port 4 is set so that the vehicle 1 always enters the stop position P in a constant direction, the stop position P It can be considered that the orientation of the vehicle 1 is substantially constant. That is, for example, referring to FIG. 1, it can be considered that the vertical direction in the drawing and the front-back direction of the vehicle 1 are substantially the same. In such a case, the rectangular shape can be uniquely determined from one diagonal line without separately setting the aspect ratio.

  When it is desired to more precisely grasp the range occupied by the vehicle 1, in addition to the pair of range sensors 5 shown by solid lines in FIGS. 1 and 2, another pair of range sensors 5c, 5d as shown by broken lines in FIG. May be arranged, and a quadrangle having a total of four closest points N as vertices may be hypothesized. In this case, it is not necessary to regard the area occupied by the vehicle 1 as a rectangle or to set the aspect ratio of the rectangle for convenience. Whether the general shape of the vehicle 1 in a plan view is a rectangle or a quadrangle other than the rectangle, for example, a trapezoid, the shape of the quadrangle can be uniquely determined from the two diagonal lines.

  Alternatively, three of the range sensors 5a to 5d indicated by solid lines or broken lines in FIG. 1 may be actually arranged, and a quadrangle having a total of three closest points N as vertices may be virtualized.

  However, for applications such as foreign object detection in a mechanical parking lot, the shape of the detection exclusion area A0 is not required to be so strict. Further, there are rarely vehicles having a shape that deviates significantly from a rectangle in a plan view. Therefore, although depending on the application, the above-described method of acquiring the two closest diagonal points N with the pair of range sensors 5 and setting the detection exclusion area A0 to a rectangle is sufficient for practical use. By doing so, the number of the range sensors 5 to be installed can be a minimum of two, and the system configuration can be simplified to reduce the installation cost.

  From the point of setting the detection exclusion area A0, it is also possible to acquire two front and rear vertices on either one of the left and right sides of the vehicle 1 and virtualize a rectangle whose long sides are line segments formed by the two vertices. is there. That is, for example, the two nearest points N are acquired by the range sensor 5a and the range sensor 5d, or the range sensor 5b and the range sensor 5c shown in FIG. 2, and the line segment formed by them is taken as one side, and the predetermined aspect ratio is set. Is a virtual rectangle. However, in such a method, the two range-finding sensors 5 used for setting the rectangle cannot cover the entire circumference of the stop position P in the measurement range, and in order to properly detect the foreign matter, further measurement is eventually performed. Area sensor 5 is required. Therefore, in the sense that the number of the range sensors 5 is minimized, it is preferable to dispose the pair of range sensors 5 at the positions of the range sensors 5a and 5b or the range sensors 5c and 5d in FIG. . As described above, the detection exclusion area A0 is strictly set for the vehicle 1, the accuracy of foreign object detection is increased, or a wide measurable range is ensured. Alternatively, five or more range sensors 5 may be arranged in the target area A freely.

  A quadrangle imaginary with the closest point N as the vertex as described above may be set as the detection exclusion area A0 as it is, but in consideration of the various shapes of the vehicle 1, for example, the quadrangle is further outward by a predetermined distance. The detection exclusion area A0 may be set as an area that is expanded by just the above (in the example shown in FIG. 2, the detection exclusion area A0 is defined as a range in which a rectangle having the two closest points N as vertices is expanded to some extent).

  Here, depending on the direction of the vehicle 1, it is theoretically possible that the appropriate detection exclusion area A0 cannot be set from the position of the closest point N as shown in FIG. For example, when the vehicle 1 stops in a direction in which the side surface of the vehicle 1 is perpendicular to the center line of the measurement range of the range sensor 5, one point on the side surface of the vehicle 1 when viewed from the range sensor 5 is the closest point. May be detected as. The detection exclusion area set based on the closest point acquired in such a state greatly differs from the area actually occupied by the vehicle 1. However, in equipment such as a mechanical parking lot, the direction of the vehicle 1 that stops in a specific range (here, the stop position P) can be managed so as to follow a certain direction even if there is some error. it can. For example, in the case of the target area A as shown in FIG. 1, since the vehicle 1 enters from the lower side in the figure, it can be considered that the front-back direction of the vehicle 1 is substantially along the up-down direction in the figure. Therefore, as described above, if the range finding sensors 5a and 5b are installed at positions diagonally front of the vehicle 1 and diagonally rearward of the stopping position P, an appropriate pair of nearest points N can be obtained. Can be obtained.

  Depending on the structure in the target area A, a pillar or the like (not shown) exists near the stop position P, and the pillar or the like prevents acquisition of the detected point data corresponding to the corner of the vehicle 1 as the closest point N. There is a possibility that In such a case, the detected point data corresponding to a pillar or the like may be excluded from the data candidates treated as the closest point N. For example, only the detected point data detected in the range where there is no pillar or the like or the range where the vehicle 1 may stop is used as a candidate for the closest point N. Alternatively, data corresponding to a pillar or the like may be excluded from the acquired detected point data. For example, the detected point data is acquired in a state where the vehicle 1 is not in the stop position P and there is no foreign object O near the stop position P, and the detected point data acquired when the vehicle 1 stops at the stop position P Calculate the difference from the data. If the detected point data corresponding to the closest point N is selected from the difference data, the data corresponding to the pillar or the like is excluded from the candidates for the closest point N.

  The data of each detected point acquired by each range sensor 5 is input to the control device 6 as a measurement signal 5e and processed. 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.

  An operation unit 7 is provided on the outer wall near the loading / unloading port 4. When the operation unit 7 is operated, the operation signal 7a according to the content of the operation is input to the control device 6. The control device 6 is configured to execute various operations such as opening / closing the loading / unloading port 4 and conveying the pallet 2 in response to the input of the operation signal 7a. The installation position of the operation unit 7 is not limited to the example shown here, and an appropriate position suitable for the operation of each unit including the loading / unloading port 4 can be selected.

  A position sensor 8 is arranged near the pallet 2 in the target area A. The position sensor 8 is a device that irradiates the measurement range with an irradiation wave such as a laser beam or an ultrasonic wave, and detects the presence or absence of an object within the measurement range, the distance, speed, and the like of the object by the reflected wave. In the present embodiment, as shown in FIG. 1, the position sensor 8 irradiates the irradiation wave toward the stop position P and observes the reflected wave, and the position information of the object detected by the position sensor 8 is , And is transmitted to the control device 6 as the position signal 8a. Then, when the vehicle 1 stops at the stop position P in the pallet 2, the control device 6 can recognize the stop of the vehicle 1.

  The mechanism for determining the stop of the vehicle 1 is not limited to the example shown here. For example, as the position sensor, various types of devices can be used as long as the stop of the vehicle 1 can be determined, and the number of installations, positions, etc. can be set appropriately. Alternatively, the range sensor 5 may be used for determining whether the vehicle 1 is stopped.

  Alarm devices 9 are provided at various locations inside and outside the target area A. The alarm device 9 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 inputting 9a. “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 9 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 9 may be provided at other places as necessary. . For example, the alarm device 9 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 5e, the operation signal 7a, the position signal 8a, and the alarm signal 9a may be exchanged by wire or wireless. As an example, the control device 6 and the range sensor 5, the operation unit 7, the position sensor 8, and the alarm device 9 can be connected to each other by Ethernet (registered trademark) or the like and 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, the foreign matter O in the target area A is detected. To detect the foreign matter O, for example, as described later, the state in the target area A at a certain time point may be compared with the state in the target area A at another time point. That is, the measurement of the target area A is performed by the range sensor 5 at each time point, the acquired detected point data are compared with each other, and it is determined that a foreign substance is detected when a difference of more than a predetermined value is seen between the data. To do.

  By the way, in the target area A which is the loading / unloading space of the mechanical parking lot, the foreign object O is detected in the state where the vehicle 1 is present at the stop position P and the sky where the vehicle 1 is not present at the stop position P. Both cases of detecting the foreign matter O in the room state can be assumed. When the foreign matter detection is attempted to be performed by comparing the detected point data as described above, the presence or absence of the vehicle 1 may interfere with the foreign matter detection. That is, when the vehicle 1 is at the stop position P on the one hand and the vehicle does not exist on the other hand at both of the time points relating to the comparison, there is a difference in the detected point data depending on the presence or absence of the vehicle 1, and even if the foreign matter O is not actually present. It is determined that the foreign matter is detected.

  In order to avoid such a situation and correctly detect the foreign matter, the detected point data are compared with each other in a state where the same vehicle 1 exists at the same position as the stop position P in the same posture, or the vehicle within the target area A is detected. It suffices to compare the states where 1 does not exist.

  However, it is preferable that such a time limit is as small as possible. For example, foreign object detection can be performed by comparing the target area A in the vacant state with the target area A in which the vehicle 1 is stopped at the stop position P. It is more convenient to use. For this purpose, the presence / absence of the vehicle 1 may be excluded from the determination target of the foreign matter detection, and the foreign matter detection may be performed only in the area other than the vehicle 1.

  The inventions described in Patent Documents 2 and 3 are technologies developed based on such an idea. In Patent Document 2, the tire is recognized from the position of the center of gravity of the object, and the position and angle of the automobile are specified. In Patent Document 3, the contour of the vehicle is acquired, and foreign matter is detected in the residual detection range excluding the range of the vehicle contour data.

  In the present embodiment, as in the techniques described in Patent Documents 2 and 3, a method of excluding the vehicle 1 from the determination of foreign matter detection is adopted, but the specific calculation processing for that is different. As described above, the coordinates of the closest point N are acquired from the detected point data of at least a pair of range sensors 5, and the detection exclusion area A0 is set as the range occupied by the vehicle 1 based on this (see FIG. 2). The foreign matter is detected in areas other than the detection exclusion area A0.

  When setting the detection exclusion area A0, it is necessary that the vehicle 1 is stopped at the stop position P and that the foreign matter O is not present in the vicinity of the vehicle 1, and this condition is satisfied. The measurement by the range sensor 5 is performed, and the position of the closest point N is acquired from the detected point data. If this condition is satisfied, the detected point data at any time may be used for setting the detection exclusion area A0. For example, as described below, when the vehicle 1 is stored, the target area A0 is set. It is preferable to use the detected point data acquired when the vehicle 1 enters the vehicle and stops at the stop position P. The stop of the vehicle 1 can be detected by the position sensor 8, and immediately after the stop of the vehicle 1, it is considered that the occupant in the vehicle 1 has not yet exited and the foreign matter O does not exist in the vicinity. is there.

  It should be noted that, in setting the detection exclusion area A0, "absence of foreign matter O in the vicinity of the vehicle 1" is necessary as a condition, but "existence of foreign matter O in the target area A" is not always necessary. . It suffices that the corner portion of the vehicle 1 in plan view can be acquired as the closest point N by each range sensor 5. That is, in the measurement range of each range sensor 5, it is sufficient that the foreign matter O does not exist at a point that is less than or equal to the shortest distance from the vehicle 1, and even if the foreign matter O exists at a distance that exceeds the shortest distance from the vehicle 1, it is detected. There is no effect on the setting of the exclusion area A0.

  The procedure for setting the detection exclusion area A0 will be described with reference to the flowchart of FIG.

  When the vehicle 1 is stored, personnel such as a driver of the vehicle 1, an occupant, and a staff member of the facility operate the operation unit 7 to give an instruction to start the storage. The control device 6 opens the loading / unloading port 4 according to the instruction. 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.

  It should be noted that the start of warehousing does not necessarily have to be performed by input to the operation unit 7, and 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 entrance / exit opening 4 of the target area A that is the entry / exit space, and automatically enters, the situation where there is no personnel to operate the operation unit 7 is assumed. In such a case, for example, a sensor that detects the vehicle 1 in front of the loading / unloading port 4 is separately provided, and when the vehicle 1 is detected by the sensor, the pallet 2 is transported and the loading / unloading port 4 is subject to the detection signal input. May be executed. Alternatively, some signal may be output from the vehicle 1 at the time of storage.

  When the vehicle 1 enters the target area A through the loading / unloading port 4 and stops at the stop position P on the pallet 2, the stop of the vehicle 1 is detected by the position signal 8a from the position sensor 8 (step S1). When the stop of the vehicle 1 is detected, the control device 6 operates the range sensor 5 to measure the inside of the target area A (step S2).

  Next, the coordinates of the closest point N (see FIG. 2) are specified from the detected point data acquired by each range sensor 5 (step S3). That is, the detected point detected at the closest distance from each range sensor 5 is set as the closest point N, and the coordinates are acquired. Here, when there is a pillar or the like near the range sensor 5, the data corresponding to the pillar or the like is excluded from the candidates for the closest point N, as described above.

  As shown in FIG. 2, the detection exclusion area A0 is set from the coordinates of the nearest point N acquired by the range sensor 5, respectively (step S4). As described above, a quadrangle having the closest point N as its apex is hypothesized, and the detection exclusion area A0 is set based on the quadrangle.

  Next, the foreign matter detection process will be described with reference to the flowchart of 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, after the vehicle 1 has been stored, the foreign matter detection process is automatically started when the setting of the detection exclusion area A0 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 process may be started at the time when the transportation of the vehicle 1 is instructed by the operation of the operation unit 7, the transportation is performed when the foreign matter O is not detected, and the transportation may be stopped when the foreign matter O is detected. good.

  Similarly, when the vehicle 1 is leaving the vehicle, the unattended person in the target area A is confirmed before the vehicle 1 is transported into the target area A or before the vehicle 1 is transported to open the loading / unloading port 4. It may be done. In addition, when entering and exiting the warehouse, it is possible to envisage a mode in which the foreign matter detection process is executed before closing the warehouse entrance 4 and the door operation is performed after confirming the absence of the foreign matter O.

  In the foreign matter detection step, the detected point data at an arbitrary time point (for example, real time) at which foreign matter detection is desired is compared with the detected point data obtained at another time point, and if a difference of a predetermined value or more is found, the foreign matter O Is determined to have been detected. Therefore, when foreign matter detection is performed, it is necessary to acquire detected point data serving as a reference for comparison, in addition to the detected point data at an arbitrary time point (hereinafter referred to as “reference data”).

  Therefore, in the present embodiment, prior to acquiring the detected point data at an arbitrary time point, measurement is performed by the range sensor 5 when the room is vacant, and the detected point data is acquired as reference data (step S11). ). Note that, in FIG. 4, for convenience, steps S11 to S13 and the subsequent steps are displayed as a series of flows, but the reference data is acquired at any time when the foreign matter O does not exist in the target area A. You may. Further, the processing of the obtained reference data (step S12 described later) may be executed independently of the steps after step S13.

  Here, the reference data is not limited to the detected point data in the vacant room, that is, "the detected point data in a state where there is no foreign object O in the target area A and there is no vehicle 1", but "except for the detection exclusion area A0" “Detected point data in a state where there is no foreign matter O” can be used. That is, if there is no foreign matter O other than the detection exclusion area A0, the detected point data in the state where the vehicle 1 exists in the detection exclusion area A0 may be used as the reference data. For example, when the process shown in FIG. 3 is executed after the vehicle 1 is stored and the detection exclusion area A0 is set, the detected point data used for setting the detection exclusion area A0 may be used as the reference data. The above is possible. This is because the foreign matter O is detected in the area other than the detection exclusion area A0 in the foreign matter detection step described below, and thus the presence or absence of the vehicle 1 in the detection exclusion area A0 does not affect the result of foreign matter detection. However, since the detection exclusion area A0 varies depending on the size, type, position, angle, etc. of the vehicle 1, when the detected point data in the state where the vehicle 1 exists is used as the reference data, the vehicle 1 at the stop position P The detected point data at the same time points should be compared. For example, if it is desired to detect foreign matter when leaving the warehouse, the detected point data used for setting the detection exclusion area A0, which is acquired when the same vehicle 1 enters the warehouse, may be used as the reference data. Since the position and the angle of the vehicle 1 on the pallet 2 should match when the same vehicle 1 is stored and when it is subsequently discharged, it can be used for comparison for foreign matter detection.

  However, when detecting foreign matter, it is complicated to call up corresponding reference data each time. Since the detected point data in the vacant room is constant regardless of the state of the vehicle 1, it is the simplest and suitable as the reference data used in the foreign matter detection process described below.

  Subsequently, from the reference data acquired in step S11, the detected point data detected at the position from the floor surface to the reference height (for example, up to half the tire height of a general passenger car) is extracted (step S12). This is because the detected point data to be compared are narrowed down and the processing efficiency is improved. To detect the foreign matter O, it is sufficient to detect only the object near the floor surface.

  In step S13, detected point data at an arbitrary point in time when foreign matter detection is desired is acquired. When performing real-time foreign matter detection, the range sensor 5 is activated at this point to measure the inside of the target area A. In the next step S14, the detected point data detected at the position from the floor surface to the reference height is extracted from the detected point data acquired in step S13. This is the same as the processing performed on the reference data in step S12.

  In subsequent steps S15 and S16, the detected point data acquired and extracted in steps S13 and S14 are compared with the reference data acquired and extracted in steps S11 and S12. Further, in steps S17 to S19, as a result of the comparison performed in steps S15 and S16, it is determined whether or not a difference larger than a predetermined value is found between the data, and based on this, the detected point data is acquired in step S13. It is determined whether or not the foreign matter O is present in the target area A at the time. The steps S15 to S19 are performed with respect to the detection points corresponding to the areas other than the detection exclusion area A0 in the reference data acquired / extracted in steps S11 and S12 and the detection point data acquired / extracted in steps S13 and S14. Only do. When excluding the detected point data relating to the detection exclusion area A0, for example, only the detected point data corresponding to the detection exclusion area A0 can be excluded from each data at the stage after step S11 and before step S16. . Alternatively, when performing steps S15 to S17, each process may be performed only on the detected point data corresponding to an area other than the detection exclusion area A0 in each data.

  In step S15, the difference between the extracted two data is calculated for each range sensor 5. Processing such as downsampling and noise removal is performed on the difference data, and labeling processing is performed on the remaining detected point data (step S16). In this step S16, for example, when a plurality of detected points are present at 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 step S17, the number of foreign matters O is counted in the labeled difference data of each range sensor 5. In one or more range-finding sensors 5, if one or more foreign object O detected point data is recognized in the difference data corresponding to a region other than the detection exclusion region A0, a detection flag is set (step S18), and the foreign substance detection process is performed. Ends. If there is no detected point data that is considered to be foreign matter O in the areas other than the detection exclusion area A0 in the difference data of any of the range sensors 5, the detection flag is not set (step S19), 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 9 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, in order to exclude the vehicle 1 from the target of the foreign matter detection, in the present embodiment, a quadrangle is hypothesized from the closest point N acquired by each range sensor 5. However, the detection exclusion area A0 is set. Unlike the techniques disclosed 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 acquiring vehicle contour data. Only a very simple calculation needs to be performed, and high-speed and highly reliable detection is possible.

  Further, since the process of recognizing the tire as in the technique described in Patent Document 2 is unnecessary, the foreign substance O is present between the range sensor 5 and the tire at the time of detecting the foreign substance, and the irradiation wave to the tire is detected. Even if there is something that blocks the object, it does not hinder the detection of foreign matter. In the technique described in Patent Document 2, the tire that is an object belonging to the vehicle is excluded from the foreign matter detection, and therefore the tire needs to be recognized at the time of foreign matter detection. However, in the present embodiment, the range occupied by the vehicle 1 is Since the detection exclusion area A0 is set in advance, it is not necessary to recognize the vehicle 1 at the time of foreign object detection.

  In the above description, the detected point data acquired at different time points are compared with each other, and the foreign matter detection is performed based on the presence or absence of the difference or the size of the difference. However, in addition to this, for example, according to the following method, the difference is detected. It is possible to detect a foreign object without taking it. First, the detected point data at an arbitrary time when foreign matter detection is desired is acquired, and the detected point data detected near the floor surface is extracted from the data. Among them, the detected point data corresponding to the structures such as columns, walls, and floors are excluded from the detected point data detected in the area other than the detection exclusion area, and if there is remaining detected point data, the detected point data The data can be considered as the foreign substance detection point data, and it can be determined that the foreign substance is detected. If the shape of the floor or the structure in the target area is simple, the amount of calculation for excluding the detection point data is small, which is an effective method. In addition, the specific step of foreign matter detection is not limited to the above-described embodiment, and if foreign matter detection can be performed based on detected point data detected in a region other than the detection exclusion region in the foreign substance detection target region. , Various steps can be adopted.

  Further, here, as an example of the target area A, a storage space including only the pallet 2 as a 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 that measures the inside of the target area A into which the vehicle 1 enters is arranged with respect to the target area A, and the vehicle 1 stops at the stop position within the target area A. Step S2 of acquiring the detected point data by the range sensor 5 while stopped at P, and step S4 of setting the detection exclusion area A0 based on the closest point N measured by the range sensor 5, respectively. In the area A, steps S11 to S19 for detecting foreign matter based on the detected point data detected in the area other than the detection exclusion area A0 are included. By doing so, the range occupied by the vehicle 1 in the target area A can be set as the detection exclusion area A0 by a simple calculation. Then, by detecting the foreign matter in the area other than the detection exclusion area A0, the vehicle 1 can be excluded from the foreign matter detection target, and the foreign matter O can be appropriately detected.

  In the foreign matter detection method according to the present embodiment, at least one pair of range finding sensors 5 (range finding sensors 5a, 5b) are provided at diagonally forward and diagonally backward positions of the stop position P so as to face each other with the vehicle 1 stopped at the stop position interposed therebetween. ) Is arranged, the detection exclusion area A0 can be set based on a rectangle having a diagonal line segment connecting the closest points N acquired by the pair of range sensors 5a and 5b. With this configuration, the pair of range sensors 5a and 5b can include the entire circumference of the stop position P in plan view in the measurement range of the range sensor 5, and the entire area around the vehicle 1 can be completely covered with the foreign matter. Detection can be performed. Further, with respect to the vehicle 1 having a shape that is substantially rectangular in a plan view, an appropriate detection exclusion area A0 can be set by the minimum number of range sensors 5.

  In the foreign matter detecting method of the present embodiment, in steps S15 and S16 of comparing the detected point data acquired at the arbitrary time point with the reference data, the data related to the detected points below the reference height from the floor surface are compared with each other. Can be used for. In this way, by narrowing down the detected point data to be compared, it is possible to improve the efficiency of the processing performed when detecting a foreign substance.

  In the foreign matter detection method of this embodiment, the detected point data acquired when the vehicle 1 enters the target area A and the vehicle 1 stops at the stop position P is used for setting the detection exclusion area A0. it can.

  In the foreign matter detection method of the present embodiment, steps S11 to S19 of detecting a foreign matter include step S11 of acquiring the detected point data as reference data by the range sensor 5 in a state where there is no foreign matter O in the target area A, In step S13 of acquiring the detected point data by the range sensor 5 at an arbitrary time, in steps S15 and S16 of comparing the detected point data acquired at the arbitrary time with the reference data, and in the steps S15 and S16. In the target area A, except the detection exclusion area A0, when a difference of a predetermined value or more is found between the data, it is determined that the foreign matter O is present in the target area A at the arbitrary time points S17 to S19. Can be included.

  In the foreign matter detection method according to the present embodiment, the reference data is the time when the vehicle 1 enters the target area A and the vehicle 1 stops at the stop position P, or there is no foreign object O in the target area A and the stop position is The detected point data may be acquired when P does not have the vehicle 1.

  In addition, the foreign matter detection system of this embodiment includes a range sensor 5 that measures the inside of the target area A into which the vehicle 1 enters, and a control device 6 that processes detected point data of the range sensor 5, The device 6 acquires the closest point N from the detected point data of the range sensor 5 in a state where the vehicle 1 is stopped at the stop position P in the target area A, and detects the detection exclusion area A0 based on the closest point N. It is configured to perform foreign object detection based on the detected point data detected in the target area A other than the detection exclusion area A0. By doing so, the range occupied by the vehicle 1 in the target area A can be set as the detection exclusion area A0 by a simple calculation. Then, by detecting the foreign matter in the area other than the detection exclusion area A0, the vehicle 1 can be excluded from the foreign matter detection target, and the foreign matter O can be appropriately detected.

  In the foreign matter detection system of the present embodiment, at least one pair of the range finding sensors 5 (the range finding sensors 5a, 5a, 5b) is arranged, and the detection exclusion area A0 is configured to be set based on a rectangle having a diagonal line segment connecting the closest points N acquired by the pair of range sensors 5a and 5b. With this configuration, the pair of range sensors 5a and 5b can include the entire circumference of the stop position P in a plan view in the measurement range of the range sensor 5, and the entire area around the vehicle 1 can be completely covered with the foreign matter. Detection can be performed. Further, with respect to the vehicle 1 having a shape that is approximately rectangular in a plan view, an appropriate detection exclusion area A0 can be set by the minimum number of range sensors 5.

  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 Transport Port 4 Entry / Exit Port 5 Range Sensor 5a Range Sensor 5b Range Sensor 5c Range Sensor 5d Range Sensor 5e Measurement Signal 6 Controller 7 Control Panel 7a Operation Signal 8 Position Sensor 8a Position Signal 9 Alarm device 9a Alarm signal A Target area A0 Detection exclusion area N Nearest point O Object (foreign matter)
P stop position

Claims (8)

A range sensor that measures the inside of the target area where the vehicle enters is arranged for the target area,
In a state where the vehicle is stopped at a stop position in the target area, a step of acquiring detected point data by the range sensor,
A step of setting a detection exclusion area based on the closest point measured by each of the range sensors,
A foreign matter detection method, comprising: performing foreign matter detection based on detected point data detected in an area other than the detection exclusion area in the target area. At least one pair of the range sensors are arranged diagonally forward and diagonally rearward of the stop position so as to face each other with the vehicle stopped at the stop position interposed therebetween.
The foreign matter detection method according to claim 1, wherein the detection exclusion area is set based on a rectangle whose diagonal is a line segment connecting the closest points acquired by the pair of range sensors.   The foreign matter according to claim 1 or 2, wherein in the step of comparing the detected point data acquired at the arbitrary time point with the reference data, the data related to the detected points below the reference height from the floor surface are used for comparison. Detection method.   The foreign matter detection method according to any one of claims 1 to 3, wherein the detected point data acquired when the vehicle enters the target area and the vehicle stops at the stop position is used for setting the detection exclusion area. . The step of detecting the foreign matter includes
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,
In the step, in regard to a region other than the detection exclusion region in the target region, 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 region at the arbitrary time point, The foreign matter detection method according to any one of claims 1 to 4. The reference data is
When the vehicle enters the target area and stops at the stop position, or
It is the detected point data acquired when there is no foreign object in the target area and there is no vehicle at the stop position.
The foreign matter detection method according to claim 5. A range sensor that measures the inside of the target area where the vehicle enters,
A control device for processing the detected point data of the range sensor,
The control device is
With the vehicle stopped at the stop position in the target area, obtain the closest point from the detected point data of the range sensor, and set the detection exclusion area based on the closest point.
A foreign matter detection system configured to perform foreign matter detection based on detected point data detected in an area other than the detection exclusion area in the target area. At least one pair of the range sensors are arranged diagonally forward and diagonally rearward of the stop position so as to face each other with the vehicle stopped at the stop position interposed therebetween.
The foreign matter detection system according to claim 7, wherein the detection exclusion area is configured to be set based on a rectangle whose diagonal line is a line segment connecting the closest points acquired by the pair of range sensors.

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