Detection device, autonomous travel device, and detection method

Abstract

This detection device comprises: an optical sensor that radiates light in the surrounding directions, and for each direction, outputs the distance to a measurement point that the light hit and the brightness of the light that hit the measurement point and returned; and a detection unit that detects the existence of an object at the measurement point on the basis of the distance, and detects a reference point of the object by setting, as external to the object, a measurement point having lower brightness compared to the brightness at each of a plurality of the measurement points belonging to the object.

Description

Detection device, autonomous driving device, and detection method

[0001] The present invention relates to a detection device, an autonomous mobile device, and a detection method.

[0002] Conventionally, there are known detection devices that detect objects using optical sensors that irradiate the surrounding area with light such as a laser, and autonomous driving devices that travel based on object detection by the detection devices. For example, Patent Literature 1 discloses a vehicle equipped with a laser sensor that tracks a detected tracking object.

[0003] Japanese Patent Application Laid-Open No. 2017-116445

[0004] However, when positioning an autonomous vehicle relative to an object using the edge of the object as a reference, a phenomenon was discovered in which the data obtained by the optical sensor for the edge of the object appeared to indicate that the object was extending in the direction of the light. This phenomenon resulted in erroneous detection of reference points used for navigation by the autonomous vehicle, such as the edge of an object or the gap between adjacent objects.

[0005] Therefore, an object of the present invention is to improve the accuracy in detecting reference points of an object.

[0006] One aspect of the detection device of the present invention includes an optical sensor that irradiates light in each direction around the surrounding area and outputs, for each direction, the distance to the measurement point where the light hits and the brightness of the light that hits the measurement point and returns; and a detection unit that detects the presence of an object at the measurement point based on the distance, and detects a reference point of the object by defining a measurement point that has a brightness smaller than the brightness of multiple measurement points that belong to the object as being outside the object.

[0007] Furthermore, one aspect of the autonomous driving device according to the present invention includes the detection device and a driving unit that drives based on the reference point detected by the detection device. Also, one aspect of the detection method according to the present invention includes the steps of irradiating light in each direction around the surroundings and, for each direction, acquiring the distance to a measurement point where the light hits the measurement point and the brightness of the light that hits the measurement point and returns, detecting the presence of an object at the measurement point based on the distance, and detecting a reference point of the object by designating a measurement point with a brightness lower than the brightness of a plurality of measurement points belonging to the object as being outside the object.

[0008] According to the present invention, the accuracy in detecting the reference points of an object is improved.

[0009] FIG. 1A is a front view showing the appearance of an autonomous mobile device of this embodiment. FIG. 1B is a side view showing the appearance of an autonomous mobile device of this embodiment. FIG. 1C is a top view showing the appearance of an autonomous mobile device of this embodiment. FIG. 2A is a front view showing a modified example of the appearance of an autonomous mobile device. FIG. 2B is a side view showing a modified example of the appearance of an autonomous mobile device. FIG. 2C is a top view showing a modified example of the appearance of an autonomous mobile device. FIG. 3 is a block diagram showing the functional configuration of an autonomous mobile device of this embodiment. FIG. 4 is a diagram showing an example of map information. FIG. 5 is a diagram schematically showing reference point detection. FIG. 6 is a flowchart showing a procedure for detecting reference points and reference directions. FIG. 7 is a diagram schematically showing grouping of measurement points. FIG. 8 is a diagram schematically showing regrouping. FIG. 9 is a diagram showing a detected straight line. FIG. 10 is a flowchart showing an example of travel control of an autonomous mobile device. FIG. 11 is a diagram showing a travel path of an autonomous mobile device under travel control. FIG. 12 is a diagram showing another travel control. FIG. 13 is a diagram showing travel control for a detected object having multiple dark areas. Fig. 14 is a top view showing alignment with respect to charging equipment. Fig. 15 is a front view showing alignment with respect to charging equipment. Fig. 16 is a diagram showing alignment with respect to multiple charging equipment. Fig. 17 is a diagram showing alignment when the placement of charging equipment is different. Fig. 18 is a diagram showing column control based on the alignment shown in Fig. 17.

[0010] Hereinafter, embodiments of the detection device, autonomous driving device, and detection method of the present disclosure will be described in detail with reference to the accompanying drawings. However, to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially identical configurations may be omitted. Furthermore, elements shown in earlier-described figures may be appropriately referenced in the description of later figures.

[0011] <Configuration of Autonomous Mobile Device> Figures 1A to 1C are diagrams showing the appearance of an autonomous mobile device of this embodiment. Figure 1A shows a front view, Figure 1B shows a side view, and Figure 1C shows a top view. The autonomous mobile device 100 of this embodiment is a device known as an AMR (Autonomous Mobile Robot) that transports materials and the like in factories, public places, etc.

[0012] The autonomous mobile device 100 includes a main body 101, a platform 102, wheels 103, casters 104, and a laser sensor 105. The main body 101 houses a control computer, a driving power supply, etc. The main body 101 has a rectangular shape when viewed from above, for example.

[0013] The loading platform 102 also serves as the upper surface of the main body 101, and materials and other cargo are loaded onto the loading platform 102. The size of the cargo may exceed the size of the loading platform 102 or the main body 101, but for the sake of convenience, the following description will be given assuming that the cargo fits within the size of the loading platform 102, unless otherwise specified.

[0014] As an example, the wheels 103 are provided at two locations, one on the left and one on the right side of the main body 101, and are driven to rotate by a motor inside the main body 101. The left and right wheels 103 can be driven independently, and the autonomous mobile device 100 can move forward, backward, turn in place, and turn by driving the left and right wheels 103. Turning is a movement in which the autonomous mobile device moves in a curved, arc-like manner.

[0015] As an example, the casters 104 are provided at each of the four corners of the main body 101 and support the main body 101 to prevent it from tilting. The casters 104 have no driving force and roll in accordance with the movement of the main body 101, and their direction also changes in accordance with the movement of the main body 101. The laser sensor 105 is an example of an optical sensor that irradiates laser light L in each direction around it and outputs, for each direction, the distance to a measurement point where the laser light L hits, and the brightness of the laser light L that hits the measurement point and returns.

[0016] The laser sensor 105 is provided, for example, in the left front corner of the main body 101. As shown by dotted lines in the front and side views, the laser sensor 105 may be provided on the right side or rear of the main body 101. For example, an LRF (Laser Range Finder) is used as the laser sensor 105.

[0017] When the laser sensor 105 is provided on the left front side of the main body 101, the laser sensor 105 detects obstacles and the like by irradiating a wide area in front of and to the left of the main body 101 with laser light L. When the laser sensor 105 is provided on the right front side of the main body 101, for example, the laser sensor 105 detects obstacles and the like by irradiating a wide area in front of and to the right of the main body 101 with laser light L.

[0018] 2A to 2C are diagrams showing modified examples of the appearance of the autonomous mobile device 100. FIG. 2A shows a front view, FIG. 2B shows a side view, and FIG. 2C shows a top view. In the modified autonomous mobile device 100 shown in FIG. 2, the laser sensor 105 is provided near the center of the main body 101. In the case of the modified autonomous mobile device 100, laser light L is irradiated over a wide area in front of and on both sides of the main body 101.

[0019] In the following description, the autonomous mobile device 100 is assumed to have a laser sensor 105 at a corner of the main body 101 as shown in Fig. 1. Fig. 3 is a block diagram showing the functional configuration of the autonomous mobile device 100 of this embodiment. The autonomous mobile device 100 includes a control unit 110, a storage unit 120, a drive unit 130, and a measurement unit 140.

[0020] The control unit 110 is a function performed by a computer built into the main body unit 101, and controls the entire autonomous mobile device 100. The storage unit 120 stores map information of the area in which the autonomous mobile device 100 will travel, and the route to be taken within that area. The map information indicates the position information of planned obstacles, landmarks, and the like.

[0021] The driving unit 130 is a function realized by the power source and motors built into the main body 101 and the wheels 103. The autonomous mobile device 100 moves when the driving unit 130 is driven according to the control of the control unit 110. The measuring unit 140 is a function realized by the laser sensor 105, and measures the surroundings of the autonomous mobile device 100 to detect actual obstacles and the like.

[0022] The control unit 110 includes a route search unit 111, a route travel unit 112, and a reference detection unit 113. The route search unit 111 searches for and determines a route to a target point based on map information stored in the storage unit 120, and stores the determined route in the storage unit 120. In this embodiment, the route search unit 111 searches for a route that can reach the target point while avoiding obstacles and the like shown in the map information, and determines the shortest route to reach the target point.

[0023] The path traveling unit 112 controls the drive unit 130 so that the autonomous mobile device 100 travels along the path stored in the storage unit 120. In this embodiment, the path traveling unit 112 also performs control to avoid obstacles measured by the measurement unit 140. The reference detection unit 113 detects a reference point and a reference direction for positioning the autonomous mobile device 100 with respect to a target shown in the map information, based on the data measured by the measurement unit 140. The reference point and reference direction detected by the reference detection unit 113 are transmitted to the path traveling unit 112 and used to control positioning by the path traveling unit 112.

[0024] As a result, the autonomous mobile device 100 travels according to the path travel unit 112 and the drive unit 130 based on the reference point and reference direction detected by the reference detection unit 113. Details of the detection of the reference point and reference direction and the positioning control will be described later.

[0025] 4 is a diagram showing an example of map information. Map information 121 shows information about walls 122 and shelves 123. The walls 122 and shelves 123 are objects that serve as obstacles or targets for the autonomous mobile device 100. When the autonomous mobile device 100 travels, it uses the laser sensor 105 to detect the actual positions of targets that are expected to exist in the surrounding area. Hereinafter, objects that are expected to exist, such as the walls 122 and shelves 123, will be collectively referred to as detected objects 200.

[0026] The autonomous mobile device 100 may be required to travel while being positioned relative to the object to be detected 200, for example, when parking in a garage or traveling through a narrow road. In such cases, it is important to detect a reference point on the object to be detected 200.

[0027] 5 is a diagram showing a schematic diagram of reference point detection. The reference point 330 of the detection object 200 is detected on the assumption that a dark portion 210 exists, for example, at an edge portion of the detection object 200. The dark portion 210 is a portion that is darker than other portions of the detection object 200.

[0028] As an example, the dark portion 210 is dark relative to the laser light L by applying paint or a material that absorbs or scatters the laser light L of the laser sensor 105 to the object to be detected 200. Specifically, the dark portion 210 may be formed by pasting black paper or by applying black paint. Alternatively, the dark portion 210 may be formed by an uneven structure on the surface of the object to be detected 200, or may be a portion that is originally provided on the object to be detected 200 without being subjected to any particular processing.

[0029] The laser sensor 105 irradiates the object to be detected 200 with laser light L and outputs the distance to the measurement point 310, 320 and the brightness for each measurement point 310, 320 where the laser light L strikes the object to be detected 200. Here, the brightness of the measurement point 310, 320 is a parameter dependent on the absorption or scattering of the laser light L at the measurement point 310, 320, and corresponds to the amount of laser light L returning from the measurement point 310, 320 to the laser sensor 105. In other words, the brightness of the measurement point 310, 320 is the apparent brightness from the laser sensor 105 side, that is, the brightness as seen by the laser light L. The dark portion 210 does not need to be dark to the human eye; it only needs to be low enough in brightness to distinguish the amount of measured light from other portions of the object to be detected 200. The dark portion 210 is, for example, a portion where the amount of laser light L returning from the dark portion 210 is less than a predetermined value. The dark portion 210 only needs to be dark with respect to the laser light L from the laser sensor 105, and may be bright with respect to light other than the wavelength of the laser light L.

[0030] In the following description, the brightness of the measurement points 310 and 320 may be referred to as "reflection intensity," but this does not mean that it satisfies the laws of reflection, etc. When referring to "reflection intensity," "reflection" refers to light returning from the measurement points 310 and 320 to the laser sensor 105, and "intensity" refers to the amount of light of the returning laser light L.

[0031] The reference detection unit 113 of the autonomous mobile device 100 detects the object to be detected 200 based on the distances to the measurement points 310 and 320. The reference detection unit 113 also regards the bright measurement point 310 as a measurement point that belongs to the object to be detected 200, and regards the bright measurement point 320 as a measurement point that is outside the object to be detected 200, and detects the reference point 330 as the boundary between them.

[0032] That is, the reference detection unit 113 detects the presence of the detection target object 200 at the measurement points 310 and 320 based on the distance. Then, the reference detection unit 113 detects the reference point 330 of the detection target object 200, excluding the measurement point 320 whose brightness is less than the brightness of the plurality of measurement points 310 belonging to the detection target object 200.

[0033] Because the reference detection unit 113 detects the reference point 330 in this manner, the accuracy in detecting the reference point 330 can be easily improved by providing a dark portion 210 that suppresses light reflection at the edge of the object to be detected 200, etc. Furthermore, as will be described later, it is also possible to create a reference point at a location other than the edge of the object to be detected 200.

[0034] The detection of the reference point and the reference direction will be described in detail below with reference to a flowchart. Fig. 6 is a flowchart showing the procedure for detecting the reference point and the reference direction. The procedure shown in the flowchart in Fig. 6 is executed by the reference detection unit 113 of the autonomous mobile device 100.

[0035] In step S101, measurement data on the distance to and brightness of the measurement points 310 and 320 is acquired from the laser sensor 105. Then, in step S102, the measurement points 310 and 320 are grouped by the inter-point distance, starting from a specific direction of the laser light L. Here, the inter-point distance is the distance between the measurement points in two-dimensional positions obtained by the direction of the laser light L and the measured distance.

[0036] An index is assigned to each direction of irradiation of the laser light L from the laser sensor 105, and the specific direction that is the starting point for grouping is indicated by the specific index. The specific index is an index that corresponds to, for example, the center direction of the detected object 200 that is expected to exist on the map information 121.

[0037] Fig. 7 is a diagram showing a schematic diagram of grouping of measurement points 310, 320. Fig. 7 shows measurement points 310, 320 on a specific detection object 200 located in the direction of laser light L0 to which a specific index is assigned. Fig. 7 also shows measurement points 350 on detection objects 200 other than the specific detection object 200, and measurement points 340 in a direction where no detection object 200 is present.

[0038] The grouping of the measurement points 310, 320, 340, and 350 begins with the measurement point 310 located in the direction of the laser light L0 with a specific index. Then, the grouping proceeds sequentially in the direction of increasing index, for example, the direction indicated by the arrow Inc in Fig. 7, and in the direction of decreasing index, for example, the direction indicated by the arrow Dec in Fig. 7. That is, for adjacent measurement points 310, 320, 340, and 350 with a different index by one, if the inter-point distance is equal to or less than a predetermined threshold, the points are included in a group, and if the inter-point distance exceeds the threshold, the grouping stops.

[0039] As a result, measurement point 340 in a direction where no detection object 200 is present and measurement point 350 on other detection objects 200 are excluded from grouping because the inter-point distance between them is far from measurement points 310 and 320 on the specific detection object 200. As a result of grouping, measurement points 310 and 320 on the specific detection object 200 are grouped into one group G1. The acquisition of measurement data and grouping are repeated even while the autonomous mobile device 100 is traveling. For this reason, the specific index may be corrected in response to changes in the position of laser sensor 105 in the forward and backward directions indicated by arrows Fr and Bk in FIG. 7 as the autonomous mobile device 100 travels.

[0040] In step S103 of FIG. 6, the standard deviation σ of the reflection intensities at the grouped measurement points 310 and 320 is calculated, and in step S104, the measurement points 310 that exhibit reflection intensities within a threshold based on the standard deviation σ are regrouped.

[0041] 8 is a diagram showing a schematic diagram of the regrouping. Of the measurement points 310, 320 grouped in step S102, the measurement points 310 whose difference from the average reflection intensity does not exceed a threshold based on the standard deviation σ are grouped into a new group G2. Because there are only a few measurement points 320 in the dark portion 210 of the detection object 200, their reflection intensity is clearly smaller than the average reflection intensity of all the measurement points 310, 320. Therefore, by using the threshold based on the standard deviation σ, they can be easily distinguished from the measurement points 310 that are outside the dark portion 210 and are excluded from group G2.

[0042] 6, among the measurement points 310, 320 grouped by the inter-point distance in step S102, the measurement points 320 with low brightness are classified into a separate group in step S104. In other words, the multiple measurement points 310, 320 are grouped into the same group based on their positional proximity based on direction and distance, and the multiple measurement points 310, 320 that were grouped into the same group based on their positional proximity are then classified into different groups based on their brightness. Therefore, accurate grouping is possible using the standard deviation σ, etc.

[0043] In step S105 of Fig. 6, a line detection process is performed based on the measurement points 310 regrouped in step S104. Fig. 9 is a diagram showing the detected line. In the line detection process, for example, a line approximation is performed on the positions of all the regrouped measurement points 310, and a line 360 ​​is detected. The line 360 ​​represents the surface position of the detection object 200. In other words, the surface of the detection object 200 is detected based on a group that includes brighter measurement points 310 from among the other groups. By using brighter measurement points 310 to detect the line 360, the surface position of the detection object 200 can be determined with high accuracy.

[0044] In step S106 of Fig. 6, for example, when the line detection process is repeatedly performed as the autonomous mobile device 100 travels, an error reduction filter is applied using data on the previously detected line 360. For example, the error of the line 360 ​​is reduced by averaging data including the previously detected data. As a result, the surface position of the object to be detected 200 can be obtained with high accuracy. The direction in which the line 360 ​​extends becomes the reference direction of the object to be detected 200.

[0045] 6, as shown in Fig. 9, the end point of the detected straight line 360 ​​on the side of the dark portion 210 is determined as the reference point 330, and a reference coordinate system 370 is obtained with the reference point 330 as the origin Σ0. In other words, the reference point 330 of the detection object 200 is detected based on the boundary between the group including the bright measurement point 310 and the group including the dark measurement point 320, among the different groups.

[0046] The end points of the line 360 ​​are boundaries where the brighter measurement point 310 transitions to the less bright measurement point 320, and therefore the positional accuracy of the end points is high. The reference coordinate system 370 is, for example, a two-dimensional coordinate system on a two-dimensional plane onto which the laser sensor 105 irradiates the laser light L. The X-axis of the reference coordinate system 370 is an extension of the line 360 ​​and indicates the reference direction. The Y-axis of the reference coordinate system 370 is a line that passes through the reference point 330 and is perpendicular to the line 360.

[0047] Furthermore, in step S107, the relative position of the laser sensor 105 with respect to the reference coordinate system 370 is estimated. The laser sensor 105 has a coordinate system 380 fixed to the autonomous mobile device 100, and the coordinate system 380 of the laser sensor 105 has an origin Σ ＬＲＦ The reference coordinate system 370 has X and Y axes. The origin Σ of the laser sensor 105 in the reference coordinate system 370 ＬＲＦ The X and Y coordinates of the laser sensor 105 are calculated, and the angles of the X and Y axes of the laser sensor 105 relative to the X and Y axes of the reference coordinate system 370 are also calculated.

[0048] In this way, by determining the reference point 330 and reference direction of the object to be detected 200, the position and angle of the laser sensor 105 relative to the object to be detected 200 can be estimated. As a result, it becomes possible to align the autonomous mobile device 100 with the object to be detected 200.

[0049] Bright measurement points 310 are suitable for confirming the presence of the detection object 200. Furthermore, by distinguishing the dimmer measurement points 320 as being outside the detection object 200, the reference points 330 on the detection object 200 are reliably detected without being overlooked. Furthermore, by performing regrouping in step S104 after the grouping in step S102 in Fig. 6, the boundaries between the brighter measurement points 310 and the dimmer measurement points 320 become clearer, and the positional accuracy of the reference points 330 improves.

[0050] <Travel Control of Autonomous Mobile Device> Next, the travel control of the autonomous mobile device 100 based on the detected reference point 330 and reference direction will be described.

[0051] 10 is a flowchart showing an example of driving control of the autonomous mobile device 100, and Fig. 11 is a diagram showing the travel path of the autonomous mobile device 100 under driving control. However, in Fig. 11, it is assumed that the laser sensor 105 is provided on the front right side of the autonomous mobile device 100. In step S201, the reference detection unit 113 of the autonomous mobile device 100 estimates the position and angle of the coordinate system 380 of the laser sensor 105, similar to step S107 in Fig. 6 .

[0052] For driving control of the autonomous mobile device 100, the estimated position and angle of the laser sensor 105 may be converted into the position and angle of the body center 151 of the autonomous mobile device 100 and used. Alternatively, for driving control of the autonomous mobile device 100, the position and angle of the laser sensor 105 may be used as is.

[0053] In the example shown in FIG. 11 , the estimated position and angle of the laser sensor 105 are converted into the position and angle of the front left corner 152 of the autonomous mobile device 100 and used for mobile control. In FIG. 11 , the moving target of the autonomous mobile device 100 is expressed in the form of coordinates (X, Y, θ) in the reference coordinate system 370 (x Ｇ , y Ｇ , 0).

[0054] In step S202, the path traveling unit 112 of the autonomous mobile device 100 controls traveling so that the difference between the target angle of movement and the angle of the autonomous mobile device 100 is eliminated. Specifically, the angle may be changed by, for example, rotating the autonomous mobile device 100 on the spot. Alternatively, as shown in FIG. 11 , arc-shaped traveling may be performed so that the difference from the target is eliminated in both angle and Y coordinate.

[0055] In step S202, the route travel unit 112 of the autonomous mobile device 100 controls travel so that there is no difference between the target position of travel and the position of the autonomous mobile device 100. In the specific example shown in FIG. 11, the X coordinate of the autonomous mobile device 100 is set to the target coordinate value "x Ｇ As a result of this driving control, the autonomous mobile device 100 is aligned with the detected object 200.

[0056] 12 is a diagram showing another driving control. In the example shown in FIG. 12, a plurality of (e.g., n) detectable objects 200 are lined up in a straight line, and the autonomous mobile device 100 travels along the line of detectable objects 200, repeatedly aligning itself with each of the detectable objects 200. The detection procedure described above reliably detects the reference coordinates 370 of each detectable object 200, so the autonomous mobile device 100 can reliably align itself with each of the multiple detectable objects 200. As a result, it becomes possible to operate the autonomous mobile device 100 by lining up multiple autonomous mobile devices 100 in a vertical row along the line of the detectable objects 200, for example.

[0057] 13 is a diagram showing travel control for a detectable object 200 having multiple dark areas 210. The detectable object 200 may have multiple dark areas 210. When the detectable object 200 has multiple dark areas 210, reference coordinates 370 corresponding to each dark area 210 are detected. As a result, even if there is actually one detectable object 200, it will be detected as being divided into multiple detectable objects 250. Therefore, in the map information 121, the detectable object 200 is also shown as multiple detectable objects 250, rather than as a single detectable object 200.

[0058] In the case shown in Fig. 13, the autonomous mobile device 100 can travel using the same travel control as that shown in Fig. 12. In other words, while traveling along one detected object 200, it can repeatedly perform positioning for each reference coordinate 370. Furthermore, multiple autonomous mobile devices 100 can be lined up in a vertical row along one detected object 200.

[0059] <Specific Applications of Driving Control> Next, specific applications of the driving control exemplified above will be described. The driving control exemplified above is applied to, for example, aligning the autonomous driving device 100 with a charging facility.

[0060] 14 and 15 are diagrams showing alignment with the charging facility. FIG. 14 shows a top view, and FIG. 15 shows a front view. A charger slave unit 410 is mounted on the autonomous mobile device 100, and charging power is supplied to the autonomous mobile device 100 wirelessly from a charger master unit 420. For proper charging, the relative positions (xＥ , y Ｅ ) must stop within an error of 10 mm.

[0061] The autonomous mobile device 100 uses the laser sensor 105 to detect a reference point and a reference direction for, for example, a wall 430 on which the charger parent device 420 is provided, and controls the travel of the autonomous mobile device 100, thereby aligning and stopping the charger child device 410 with the parent device 420. The wall 430 has a dark area 210, which enables accurate detection and alignment as described above.

[0062] 16 is a diagram showing alignment with multiple charging facilities. When multiple parent units 420 are provided to support charging of multiple autonomous mobile devices 100, if the parent units 420 are arranged in parallel, a large installation space is required to ensure space for the autonomous mobile devices 100 to travel. For this reason, it is desirable to provide multiple parent units 420 in a vertical row, for example, against a single wall 430, and to line up multiple autonomous mobile devices 100 in a vertical row along the wall 430.

[0063] 16, multiple walls 430 may be provided corresponding to multiple parent devices 420, but in the example shown in Fig. 16, multiple parent devices 420 are provided on one wall 430, and multiple dark areas 210 are provided on the wall 430 corresponding to each parent device 420. As a result, a reference point for the stop position corresponding to each parent device 420 is detected.

[0064] 16 , the autonomous mobile device 100 aligns the child device 410 with the parent device 420 provided at one end of a wall 430 and stops. If there are no other autonomous mobile devices 100 ahead, the autonomous mobile device 100 detects a reference point and a reference direction for the portion of the wall 430 corresponding to the parent device 420 immediately ahead and the dark area 210. The autonomous mobile device 100 then aligns the child device 410 with the parent device 420 immediately ahead and stops.

[0065] As a result, the child devices 410 are positioned relative to each parent device 420 and charged at each stopping position, so that multiple autonomous mobile devices 100 can be charged while lined up in a vertical row relative to the row of parent devices 420.

[0066] 17 is a diagram showing alignment when the placement of charging equipment is different. In the example shown in Fig. 17, the laser sensor 105 and the charger slave unit 410 are installed on the same side of the autonomous mobile device 100. Because the laser sensor 105 has poor measurement accuracy for distances of, for example, 100 mm or less, when the autonomous mobile device 100 approaches a wall 430 on which the master unit 420 is installed, it has difficulty detecting the wall 430.

[0067] 17 , for example, a wall-like indicator 440 is provided to indicate the stopping position, and a dark area 210 is provided in the indicator 440. The autonomous mobile device 100 travels between the wall 430 and the indicator 440 while detecting the indicator 440 with the laser sensor 105, and detects the reference point and reference direction of the stopping position based on the indicator 440 and the dark area 210. As a result, the autonomous mobile device 100 can stop at a stopping position where the child device 410 is in an appropriate relative position with respect to the parent device 420.

[0068] Fig. 18 is a diagram showing the vertical alignment control using the positioning shown in Fig. 17. In the example shown in Fig. 18, multiple parent units 420 are individually mounted on multiple walls 430 and arranged in a vertical line. The stop position indicator 440 has a dark portion 210 at a position that serves as a reference for the stop position for each parent unit 420.

[0069] The autonomous mobile device 100 travels between the row of walls 430 and the indicators 440 while detecting the indicators 440 with the laser sensor 105. The autonomous mobile device 100 then detects the reference point and reference direction for the stopping position based on the indicator 440 portion and dark area 210 corresponding to each parent device 420, and stops at the stopping position corresponding to each parent device 420. As a result, the child devices 410 are positioned relative to each parent device 420 and are charged at each stopping position.

[0070] In the above description, AMR is given as an example of an application of the autonomous driving device and the control method for the autonomous driving device of the present invention, but the application of the autonomous driving device and the control method for the autonomous driving device of the present invention is not limited to the above and can be used in a wide range of applications, such as automatic vacuum cleaners and self-driving cars. The above-described embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0071] 100: Autonomous mobile device 101: Main body 102: Loading platform 103: Wheels 104: Casters 105: Laser sensor 110: Control unit 111: Path search unit 112: Path travel unit 113: Reference detection unit 120: Memory unit 121: Map information 122: Wall 123: Shelf 130: Drive unit 140: Measurement unit 200: Object to be detected 210: Dark areas 310, 320, 340, 350: Measurement point 330: Reference point 370: Reference coordinate system 380: Coordinate system of autonomous mobile device G1, G2: Group of measurement points L: Laser light

Claims

1. A detection device comprising: an optical sensor that irradiates light in each direction around the surrounding area and outputs, for each direction, the distance to the measurement point where the light hits and the brightness of the light that hits the measurement point and returns; and a detection unit that detects the presence of an object at the measurement point based on the distance, and detects a reference point of the object by regarding a measurement point that has a brightness smaller than the brightness of multiple measurement points that belong to the object as being outside the object.

2. The detection device described in claim 1, wherein the detection unit groups the plurality of measurement points into the same group based on the proximity of their positions based on the direction and the distance, divides the plurality of measurement points that have been grouped into the same group based on the proximity of their positions into different groups based on the differences in brightness, detects the surface of the object based on a group of the different groups that includes the measurement points with high brightness, and detects a reference point of the object based on the boundary between the group that includes the measurement points with high brightness and the group that includes the measurement points with low brightness.

3. An autonomous driving device comprising: a detection device according to claim 1 or 2; and a driving unit that drives based on the reference point detected by the detection device.

4. A detection method comprising the steps of irradiating light in each direction around the object, and for each direction, obtaining the distance to the measurement point where the light hits and the brightness of the light that hits the measurement point and returns; detecting the presence of an object at the measurement point based on the distance, and detecting a reference point for the object by defining a measurement point with a brightness smaller than the brightness of multiple measurement points belonging to the object as being outside the object.

Images