Output control device, distance measuring device, output control method, output control program

Abstract

The present application provides an output control device, a distance measuring device having the output control device, an output control method, and an output control program, which can reduce the data amount of information including distance information. A control section (10) is an output control device that controls output of information included in a distance image including distance information of an object (30), and has a distance calculation section (11) and an output information selection section (19). The distance calculation section (11) acquires distance information of the object (30) based on an amount of reflection of light (L1) emitted from an illumination device (21) toward the object (30). The output information selection section (19) selects distance information corresponding to a pixel of the distance image including the object (30) detected based on distance information acquired by the distance calculation section (11) as an output target.

Description

Technical Field

[0001] The present invention relates to an output control device for controlling the output of information contained in a distance image that includes distance information to an object, as well as a ranging device, an output control method, and an output control program having the control device. Background Technology

[0002] In recent years, for example, distance measuring devices have been used. These devices accept reflected light from LEDs (Light Emitting Diodes) as light sources and direct it toward the object being measured. They then use a TOF (Time-of-Flight) sensor, which measures the distance to the object, to generate a distance image for each pixel that contains distance information to the object being measured.

[0003] For example, Patent Document 1 has disclosed a coordinate calibration method for an anthropometric system, which constructs a laboratory coordinate system from the coordinate system of the distance image obtained by a depth camera based on data of the indoor plane portion included in the distance image.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-122690 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, the existing anthropometric systems described above have the following problems.

[0009] That is, although the above-mentioned announcement discloses a method for calibrating the coordinate system of a distance image obtained by a depth camera to a laboratory coordinate system, the amount of output data may be huge because it needs to output information including distance information corresponding to all pixels of the distance image.

[0010] Therefore, the large amount of output data may increase communication time between hosts receiving the system's output. Furthermore, even in cases of post-processing of data received from the host side, such as detecting specified objects, the large amount of data being processed may increase the post-processing load on the host side.

[0011] The present invention addresses the problem of providing an output control device, a ranging device having the output control device, an output control method, and an output control program that can reduce the amount of data containing distance information from the output.

[0012] Technical solutions for solving technical problems

[0013] The first invention's output control device is an output control device for controlling the output of information contained in a distance image that includes distance information to an object, comprising: a distance information acquisition unit and an output information selection unit. The distance information acquisition unit acquires distance information to the object based on the amount of reflection of electromagnetic waves irradiated from a lighting device onto the object. The output information selection unit selects distance information corresponding to pixels of the distance image, including the object detected based on the distance information acquired by the distance information acquisition unit, as the output object.

[0014] Here, for example, the reflected light from the LED (Light Emitting Diode) that is used as a light source is received, and distance information corresponding to the pixels of the distance image, including the object being detected using distance information obtained from a TOF (Time-of-Flight) sensor that measures the distance to the object, is selected as the output object.

[0015] Here, the output control device can be installed inside the ranging device such as the TOF sensor, or it can be installed outside the ranging device.

[0016] Electromagnetic waves emitted from lighting devices include light in a broad sense (ultraviolet / visible / infrared light), gamma rays with wavelengths shorter than light, X-rays, microwaves with wavelengths longer than light, radio waves (shortwave, medium wave, long wave), ultrasound, elastic waves, quantum waves, etc.

[0017] It should be noted that the distance information acquisition unit can also be a structure that calculates distance information by detecting the reflection of electromagnetic waves, for example, it can be a structure that acquires distance information from a distance sensor or the like, which is an external device.

[0018] Therefore, for example, output control can be performed by selectively outputting only the distance information corresponding to pixels including objects placed on the ground, so as not to output the pixel parts that do not have objects on the ground.

[0019] As a result, the amount of data containing distance information output from the ranging device can be significantly reduced.

[0020] The output control device of the second invention is based on the output control device of the first invention and further includes an object detection unit. When the object detection unit detects an object with a height relative to the ground based on the distance information obtained by the distance information acquisition unit, the object detection unit detects the object as an object.

[0021] Therefore, by detecting objects that have a height relative to the surface identified as the ground as objects, it is easy to specify pixels that include distance information as the output object.

[0022] The output control device of the third invention is based on the output control device of the first or second invention, and further includes an angle information acquisition unit that acquires angle information corresponding to each pixel included in the distance image.

[0023] Thus, for example, in a ranging device that includes a light-receiving lens and an imaging element that detects the reflection of electromagnetic waves received through the light-receiving lens as a light-receiving part, since the reflection angle of the electromagnetic waves incident through the light-receiving lens is determined for each pixel of the imaging element that generates the distance image, it is possible to obtain angle information corresponding to each pixel.

[0024] The output control device of the fourth invention is based on the output control device of the third invention, and further includes a three-dimensional coordinate transformation unit, which transforms the distance information obtained by the distance information acquisition unit into three-dimensional coordinates based on the angle information obtained by the angle information acquisition unit.

[0025] Therefore, distance information can be converted into three-dimensional coordinates (X, Y, Z) by utilizing the angle information corresponding to each pixel.

[0026] The output control device of the fifth invention is based on the output control device of the fourth invention and further includes a plane detection unit that detects the ground on which the object is placed.

[0027] Therefore, as a preliminary stage before actually measuring the distance to an object, by detecting the ground, the distance (height) between the ranging device and the ground can be used as a reference value when detecting whether an object is present.

[0028] The output control device of the sixth invention is based on the output control device of the fifth invention, and further includes a height calculation unit, which calculates the setting height of the ranging device based on the three-dimensional coordinates after the distance information of the ground detected by the plane detection unit is converted by the three-dimensional coordinate transformation unit.

[0029] Therefore, it is possible to calculate the set height of the distance measuring device relative to the ground, and use the distance (height) between the distance measuring device and the ground as a reference value when detecting the presence or absence of an object.

[0030] The output control device of the seventh invention is based on the output control device of the sixth invention. The height calculation unit calculates the coordinate value of the optical axis direction obtained by rotating the orthogonal coordinate system of the ranging device around the axis and the angle formed by the perpendicular line of the ground detected by the plane detection unit and the optical axis of the ranging device, and uses it as the set height.

[0031] Therefore, for the distance to the ground measured by the distance measuring device, the coordinate value of the optical axis direction can be calculated by rotating the orthogonal coordinate system of the distance measuring device around the axis to form the angle between the perpendicular line of the ground and the optical axis of the distance measuring device, and used as the setting height of the distance measuring device.

[0032] That is, for example, by rotating the angle formed by the perpendicular line of the ground around the axis and the optical axis of the rangefinder, so that the Z-axis, which is equivalent to the optical axis of the rangefinder, is oriented in the vertical direction, the setting height can be calculated to obtain the same distance information as when the rangefinder shines light directly downwards and receives its reflected light.

[0033] The output control device of the eighth invention is based on the output control device of the seventh invention. The height calculation unit calculates the average value of the vertical coordinates of multiple coordinates obtained again by rotating the orthogonal coordinate system of the ranging device around the axis, and uses it as the setting height.

[0034] Therefore, by calculating the average value of the coordinates (distance) of the distance to the plane identified as the ground, and using this average value as the setting height, the setting height of the distance measuring device relative to the ground can be accurately calculated, even in cases where the ground has slight irregularities.

[0035] The output control device of the ninth invention is based on the output control device of the eighth invention, and further includes a coordinate rotation calculation unit, which calculates the rotation coordinates that cause the three-dimensional coordinates converted from distance information and angle information in the three-dimensional coordinate transformation unit to rotate around an axis.

[0036] Therefore, when actually measuring the distance information to an object, the distance to the object can be detected by calculating the rotation coordinates that cause the three-dimensional coordinates converted from distance and angle information in the three-dimensional coordinate transformation unit to rotate around the axis.

[0037] That is, by using the calculated rotation coordinates, it is possible to actually measure the distance in the height direction when viewed from directly above the object.

[0038] The output control device of the tenth invention is based on the output control device of the ninth invention and further includes an object detection unit. This object detection unit compares the height coordinate of the rotation coordinate calculated in the coordinate rotation calculation unit with the set height calculated in the height calculation unit. When an object with a height dimension is detected, the object is detected as an object.

[0039] Therefore, by comparing the set height relative to the ground with the height of the object (coordinate in the height direction), it is easy to detect whether an object is an object based on whether the object has a dimension in the height direction.

[0040] The output control device of the eleventh invention is based on the output control device of the tenth invention, and further includes a threshold setting unit that sets a predetermined threshold used in object detection by the object detection unit.

[0041] Therefore, when comparing the object's height (coordinate in the height direction) with the ground's set height during object detection, if the difference in height is greater than or less than a specified threshold, the object is detected as an object, thereby suppressing false detections of objects.

[0042] The output control device of the twelfth invention is based on the output control device of the tenth or eleventh invention. The output information selection unit selects distance information of each pixel, including the object detected by the object detection unit, and outputs it.

[0043] Therefore, by selectively outputting distance information from all pixels of the imaging element that corresponds only to pixels including the object, the amount of output data can be significantly reduced, thus lowering the output load.

[0044] The ranging device of the thirteenth invention comprises: an output control device of any one of the first to twelfth inventions, an illumination device for irradiating electromagnetic waves onto an object, and a light-receiving part for detecting the amount of reflection of electromagnetic waves irradiated from the illumination device.

[0045] Therefore, by placing the aforementioned output control device inside the rangefinder having an illumination device and a light-receiving part, it is possible to output distance information that corresponds only to pixels including the object, rather than all pixels of the imaging element of the light-receiving part, thus obtaining a rangefinder that can significantly reduce the amount of output data.

[0046] The fourteenth invention's ranging device is based on the thirteenth invention's ranging device, and further includes a storage unit that stores at least one of the following: distance information, angle information corresponding to each pixel included in the distance image, an orthogonal coordinate system of the ranging device, a height setting, a rotation coordinate for rotating the three-dimensional coordinates converted from the distance information and angle information around an axis, a threshold used for object detection, and coordinate values ​​of the pixels that are output objects.

[0047] Therefore, by storing distance information, angle information, orthogonal coordinate system, height setting, rotation coordinates, threshold, and coordinate values ​​of pixels as output objects in the ranging device, it is possible to utilize the various stored data to perform processing that significantly reduces the amount of output data.

[0048] The ranging device of the fifteenth invention is based on the ranging device of the thirteenth or fourteenth invention, and further includes an output unit that outputs distance information corresponding to a pixel selected by the output information selection unit to an external device.

[0049] Therefore, by outputting only the distance information corresponding to the selected pixel that is determined to include the object to the external device from the output unit, the amount of data containing the distance information output from the ranging device can be greatly reduced.

[0050] The sixteenth invention's output control method is an output control method for controlling the output of information contained in a distance image that includes distance information to an object. It includes a distance information acquisition step and an output information selection step. The distance information acquisition step acquires distance information to the object based on the amount of reflection of electromagnetic waves irradiated from a lighting device towards the object. The output information selection step selects distance information corresponding to pixels in the distance image, including the object detected based on the distance information acquired in the distance information acquisition step, as the output object.

[0051] Here, for example, the reflected light from the LED (Light Emitting Diode) that is used as a light source is received and directed toward the object. Distance information corresponding to the pixels of the distance image, including the object, is selected as the output object. The object is detected using distance information between the object and the sensor obtained from the TOF (Time-of-Flight) sensor that measures the distance between the object and the sensor.

[0052] Here, this output control method can be implemented, for example, inside a ranging device such as a TOF sensor, or outside the ranging device.

[0053] Electromagnetic waves emitted from lighting devices include light in a broad sense (ultraviolet / visible / infrared light), gamma rays with wavelengths shorter than light, X-rays, microwaves with wavelengths longer than light, radio waves (shortwave, medium wave, long wave), ultrasound, elastic waves, quantum waves, etc.

[0054] It should be noted that in the distance information acquisition step, the structure can be used to calculate the distance information by detecting the reflection of electromagnetic waves, or it can be used to acquire the distance information from a distance sensor or other external device.

[0055] Thus, for example, it is possible to selectively output only the distance information corresponding to pixels including objects placed on the ground, and to control the output so as not to output only the pixel parts where there are no objects on the ground.

[0056] As a result, the amount of data containing distance information output from the ranging device can be significantly reduced.

[0057] The output control program of the seventeenth invention is an output control program that controls the output of information contained in a distance image including distance information to an object, and executes an output control method having a distance information acquisition step and an output information selection step in a computer. The distance information acquisition step acquires distance information to the object based on the amount of electromagnetic waves reflected from the illumination device towards the object. The output information selection step selects distance information corresponding to pixels in the distance image, including the object detected based on the distance information acquired in the distance information acquisition step, as the output object.

[0058] Here, for example, the reflected light from the LED (Light Emitting Diode) that is used as a light source is received and directed toward the object. The distance information corresponding to the pixels of the distance image, including the object, is selected as the output object. The object is detected using the distance information of the object obtained from the TOF (Time-of-Flight) sensor that measures the distance to the object.

[0059] Here, this output control program can be read and executed in the CPU of a ranging device such as a TOF sensor, or it can be read and executed in the CPU of an external device of the ranging device.

[0060] Electromagnetic waves emitted from lighting devices include light in a broad sense (ultraviolet / visible / infrared light), gamma rays with wavelengths shorter than light, X-rays, microwaves with wavelengths longer than light, radio waves (shortwave, medium wave, long wave), ultrasound, elastic waves, quantum waves, etc.

[0061] It should be noted that in the distance information acquisition step, the structure can also be used to calculate the distance information by detecting the reflection of electromagnetic waves, or it can be used to acquire the distance information from a distance sensor or other external device.

[0062] Thus, for example, it is possible to selectively output only the distance information corresponding to pixels including objects placed on the ground, and to control the output so as not to output only the pixel parts where there are no objects on the ground.

[0063] As a result, the amount of data containing distance information output from the ranging device can be significantly reduced.

[0064] The effects of the invention

[0065] The ranging device according to the present invention can reduce the amount of data containing the output distance information. Attached Figure Description

[0066] Figure 1 This is a perspective view showing the external structure of a ranging device according to one embodiment of the present invention.

[0067] Figure 2 yes Figure 1 The control block of the ranging device.

[0068] Figure 3 Is Figure 2 The control block formed within the control section of the ranging device.

[0069] Figure 4 It is for calculation in Figure 2 The diagram illustrates the principle of how a distance measuring device calculates the distance to an object using the Time-of-Flight (TOF) method.

[0070] Figure 5 It means Figure 1 A diagram showing the positional relationship between a ranging device and an object placed on the ground.

[0071] Figure 6 It means to make Figure 5 A diagram showing the orthogonal coordinate form (three-dimensional coordinates) of a ranging device after rotating it around the X-axis by an angle θ.

[0072] Figure 7 It is aimed at Figure 6 The diagram illustrates the transformation of orthogonal coordinates.

[0073] Figure 8 It is aimed at Figure 6 The diagram illustrates the transformation of orthogonal coordinate rotation.

[0074] Figure 9 It is represented using orthogonal coordinate rotation. Figure 1 A diagram showing the positional relationship between a ranging device and an object placed on the ground.

[0075] Figure 10 It is represented using orthogonal coordinate rotation. Figure 1 A diagram showing the relationship between the position of the ranging device and the hole opened in the ground.

[0076] Figure 11 It is represented using orthogonal coordinate rotation. Figure 1 A diagram showing the positional relationship between the ranging device and the slope on the ground.

[0077] Figure 12 It means by Figure 1 The flowchart shows the process of output control method implemented by the ranging device and calibration process implemented before actual measurement.

[0078] Figure 13 It means by Figure 1The flowchart shows the process of processing the output control method implemented by the ranging device during actual distance measurement.

[0079] Figure 14 It is explained in detail in Figure 13 The flowchart of the detection process for the object (object) placed on the ground in step S25.

[0080] Figure 15 Is Figure 13 Detection in step S25 Figure 10 The flowchart for the process of creating holes in the ground.

[0081] Figure 16 Is Figure 13 Detection in step S25 Figure 11 The flowchart for the slope. Detailed Implementation

[0082] (First Implementation)

[0083] For a ranging device 20 having a control unit (output control device) 10 according to one embodiment of the present invention, using Figures 1 to 16 The explanation is as follows.

[0084] (1) Structure of the ranging device 20

[0085] like Figure 1 As shown, in this embodiment, the ranging device 20 receives reflected light from the light L1 (an example of an electromagnetic wave) irradiated from the illumination device 21 provided on the surface of the main body 20a toward the object 30 via the light-receiving lens 22 and the imaging element 23, and obtains distance information calculated based on the time of flight of the light L1 from irradiation to reception.

[0086] Moreover, such as Figure 2 As shown, the ranging device 20 includes: an illumination device 21, a light-receiving lens 22, an imaging element 23, a control unit (output control device) 10, a storage unit 25, and an output unit 26.

[0087] The lighting device 21, for example, has an LED that illuminates the object 30 with light of a desired wavelength. It should be noted that the lighting device 21 is provided with a projection lens (not shown) that focuses the light illuminating from the LED and guides it toward the object 30.

[0088] The light-receiving lens 22 is provided to illuminate the object 30 from the illumination device 21, receive the reflected light reflected by the object 30, and guide it to the imaging element 23.

[0089] The imaging element 23 has multiple pixels. Each pixel receives reflected light received by the light-receiving lens 22 and sends an electrical signal, which has undergone photoelectric conversion, to the control unit 10. Furthermore, the electrical signal corresponding to the amount of light received by the reflected light detected by the imaging element 23 is used by the control unit 10 to calculate distance information for each pixel.

[0090] like Figure 2 As shown, the control unit 10 is connected to the lighting device 21, the imaging element 23, and the storage unit 25. Furthermore, the control unit 10 reads the lighting control program stored in the storage unit 25 and controls the lighting device 21 that illuminates the object 30. More specifically, the control unit 10 controls the lighting device 21 to illuminate the object 30 with optimal light based on the object's properties, such as its distance, shape, and color. Additionally, the control unit 10 calculates distance information to the object 30 for each pixel based on the electrical signals received from the imaging element 23 corresponding to each pixel.

[0091] It should be noted that the principle of distance measurement between the distance measuring device 20 and the object 30 will be explained in detail later.

[0092] like Figure 2 As shown, the storage unit 25 is connected to the control unit 10 and stores control programs for controlling the lighting device 21 and the imaging element 23, as well as distance information calculated based on the amount of reflected light detected by the imaging element 23, the time of illumination, and the amount of reflected light. Furthermore, the storage unit 25 stores information such as distance information, angle information, orthogonal coordinate system, set height, rotation coordinates, threshold, and coordinate values ​​of pixels that are the output target, as described later.

[0093] Output unit 26 will be selected by output information selection unit 19 (see below) Figure 3 The selected distance information corresponding to the pixel is output to the external device.

[0094] The distance information corresponding to each pixel output from the output unit 26 is not information for all pixels, but is limited to information corresponding to a selected subset of pixels. Therefore, the output load can be reduced, and the post-processing load at the output destination, i.e., the external device, can also be reduced.

[0095] (2) Structure of the control unit 10

[0096] like Figure 3 As shown, the control unit 10 includes: a distance calculation unit (distance information acquisition unit) 11, an angle information acquisition unit 12, a three-dimensional coordinate transformation unit 13, a plane detection unit 14, a height calculation unit 15, a coordinate rotation calculation unit 16, a threshold setting unit 17, an object detection unit 18, and an output information selection unit 19.

[0097] The distance calculation unit 11 calculates the distance information between the object 30 and each pixel of the grayscale image captured by the imaging element 23, based on the distance measurement principle of the TOF (Time of Flight) method described later.

[0098] Since the incident angle between the reflected light and the subject is determined for the multiple pixels constituting the distance image generated in the imaging element 23 that receives reflected light via the light-receiving lens 22, the angle information acquisition unit 12 acquires the angle information corresponding to each pixel.

[0099] The three-dimensional coordinate transformation unit 13, based on the angle information obtained by the angle information acquisition unit 12, converts the distance information obtained by the distance calculation unit 11 into three-dimensional coordinates (X, Y, Z) in orthogonal coordinate form (see reference). Figure 7 ).

[0100] The plane detection unit 14 serves as a reference for measuring the distance to the object 30, and detects the ground FL (calibration process) by specifying the range of pixels of the ground FL on which the object 30 is placed.

[0101] The height calculation unit 15 calculates the setting height h between the ranging device 20 and the ground FL based on the three-dimensional coordinates (X, Y, Z) transformed by the three-dimensional coordinate transformation unit 13 from the distance information (height) of the ground FL detected by the plane detection unit 14. More specifically, the height calculation unit 15 calculates the coordinate value Zr in the optical axis direction of the coordinate values ​​(X, Yr, Zr) obtained by rotating the orthogonal coordinate system (X, Y, Z) of the ranging device 20 around the axis by the angle θ formed by the perpendicular line of the ground FL and the optical axis of the ranging device 20, and uses this coordinate value as the setting height h (refer to...). Figure 6 ).

[0102] In this embodiment, the height calculation unit 15 calculates the average value of the coordinate values ​​in the Z direction of multiple coordinate values ​​(Xr, Yr, Zr) obtained again by rotating the orthogonal coordinate system (X, Y, Z) of the ranging device 20 around the axis, and uses it as the set height h.

[0103] The coordinate rotation calculation unit 16 performs calculations on the rotated coordinates (orthogonal coordinate rotation form) obtained by rotating the three-dimensional coordinates (orthogonal coordinate form) transformed from distance and angle information in the three-dimensional coordinate transformation unit 13 around an axis (see reference). Figure 6 ).

[0104] The threshold setting unit 17 sets a predetermined threshold value used when the object detection unit 18 detects the object 30. It should be noted that the threshold set by the threshold setting unit 17 can be appropriately set to different values ​​according to the shape, size, etc. of the object 30 being detected.

[0105] The object detection unit 18 compares the height coordinate z of the rotation coordinate calculated by the coordinate rotation calculation unit 16 with the set height h calculated by the height calculation unit 15. When an object with a height dimension is detected, the object is detected as an object 30 placed on the ground FL.

[0106] The output information selection unit 19 selects only the distance information corresponding to the pixel including the object 30 from among the multiple pixels constituting the distance image including the object 30 that is detected based on the distance information calculated by the distance calculation unit 11, and outputs it.

[0107] <Distance Measurement Principle Based on Distance Measuring Device 20>

[0108] Based on the principle of distance measurement to an object performed by the distance measuring device 20 of this embodiment, using Figure 4 The explanation is as follows.

[0109] That is, in this embodiment, the control unit 10 (distance calculation unit 11) of the ranging device 20 is based on the phase difference Φ between the projected light wave irradiated from the illumination device 21 and the received light wave received by the imaging element 23 (refer to...). Figure 4 ), calculate the distance to object 30.

[0110] Here, the phase difference Φ is represented by the following relationship (1).

[0111] Φ=atan(y / x)…(1)

[0112] (x = a2 - a0, y = a3 - a1, a0 to a3 are the amplitudes of the points where the received light wave was sampled four times at 90-degree intervals)

[0113] Moreover, the conversion formula from phase difference Φ to distance D is represented by the following relationship (2).

[0114] D=(c / (2×f LED ))×(Φ / 2π)+D OFFSET …(2)

[0115] (c is the speed of light (≒3×10) 8 m / s), f LED D is the frequency of the light emitted by the LED. OFFSET (for deviation distance)

[0116] Therefore, by receiving the reflected light from the illumination device 21 and comparing their phase difference, the distance calculation unit 11 can easily calculate the distance to the object 30 using the speed of light c.

[0117] <Processing the selection of output objects>

[0118] The method for selecting the output target by the control unit 10 of the ranging device 20 of this embodiment will be explained below with reference to the accompanying drawings.

[0119] That is, such as Figure 5 As shown, in this embodiment, the ranging device 20 is installed at the upper end of the support P1 at a height h set on the ground FL at a downward angle, assuming that the object 30 placed on the ground FL exists.

[0120] In this case, the distance to the object (object 30, ground FL, etc.) mapped to all pixels of the imaging element 23 is calculated in the ranging device 20, and the three-dimensional coordinates (X, Y, Z) with the ranging device 20 as the origin are stored as distance information corresponding to each pixel.

[0121] In order to selectively output distance information of pixels corresponding to the position of the object 30 from the distance information corresponding to each pixel, the ranging device 20 of this embodiment performs the following output control processing.

[0122] First, as a preparation, the ranging device 20 performs calculations and calibrations at the set height h of the ground FL.

[0123] Specifically, such as Figure 5 As shown, the ranging device 20 measures the distance on the ground FL using an orthogonal coordinate system (X, Y, Z) and obtains the measurement results (X, Y, Z) coordinate values ​​of each pixel.

[0124] Next, the ranging device 20 performs plane detection on the acquired results within a specified pixel range to determine the coefficients a, b, c, and d of the equation aX+bY+cZ+d=0 for plane α.

[0125] It should be noted that the plane detection and the derivation of a, b, c, and d can be flexibly achieved using existing technologies. For example, the example code for plane detection (Plane model segmentation) provided by the Point Cloud Library can be used to calculate the values ​​(see http: / / pointclouds.org / documentation / tutorials / planar_segmentation.html, etc.).

[0126] Next, the ranging device 20 calculates the angle θ formed by the perpendicular line of the ground FL and the Z-axis of the orthogonal coordinate system of the ranging device 20.

[0127] Here, Figure 6The angle θ formed by the plane α shown and the Z-axis (z+t=0) of the orthogonal coordinate system of the ranging device 20 is obtained by the following relation (1).

[0128] θ=cos-1(|a×0+b×0+c×1|÷((a 2 +b 2 +c 2 )1 / 2×(0 2 +0 2 +1 2 )))…(1)

[0129] By measuring the distance again using the orthogonal coordinate rotation system after rotating the orthogonal coordinate system by θ degrees around the X-axis, the coordinate values ​​of the measurement results (Xr, Yr, Zr) of the orthogonal coordinate rotation system of each pixel can be obtained.

[0130] Next, the ranging device 20 calculates the average value of Zr within the plane range that was detected on plane α, and calculates this average value as the height h of the ground FL.

[0131] It should be noted that the process of converting the distance measurements of each pixel of the imaging element 23 into three-dimensional coordinates based on angle information utilizes... Figure 7 The explanation is as follows.

[0132] That is, such as Figure 7 As shown, the ranging device 20 uses angles θ and φ to convert the measured distance r corresponding to each pixel into three-dimensional coordinates X, Y, and Z.

[0133] It should be noted that, Figure 7 The definitions of r, θ, φ, X, Y, and Z are as follows.

[0134] X=r×sinθcosφ

[0135] Y=r×sinθsinφ

[0136] Z = r × cosθ

[0137] (The measured value r is the magnitude of the distance vector r, the angle θ is the angle formed by the direction of the distance vector r and the Z-axis, and the angle information φ is the angle formed by the projection vector of the distance vector r onto the XY plane and the X-axis.)

[0138] Next, for the process of rotating the three-dimensional coordinates (X, Y, Z) after transforming the measured distance values ​​corresponding to each pixel around the X-axis, Y-axis, and Z-axis respectively, and transforming them to an orthogonal coordinate rotation system, the following steps are performed: Figure 8 Please provide an explanation.

[0139] Here, the ranging device 20 specifies the rotation angles around the X-axis, Y-axis, and Z-axis, and calculates the rotated coordinate values ​​Xr, Yr, and Zr for the X, Y, and Z coordinates of all pixels using the following relationship (2).

[0140] [Equation 1]

[0141]

[0142] For example, such as Figure 8 As shown, when the three-dimensional coordinates of a certain pixel are (X, Y, Z) = (0, 1, 0), after rotating 90 degrees around the X-axis and without rotating around the Y-axis and Z-axis, the rotated coordinates are (Xr, Yr, Zr) = (0, 0, 1).

[0143] Then, using the calibration process described above, after determining the setting height h of the ranging device 20, as follows... Figure 9 As shown, the actual distance to object 30 is measured.

[0144] That is, the distance is measured in the form of orthogonal coordinate rotation after rotating θ degrees around the X-axis, and the distance measurement results (Xr, Yr, Zr) of each pixel of the imaging element 23 are obtained.

[0145] At this time, in the ranging device 20, the threshold setting unit 17 sets a predetermined threshold S1 for detecting the object 30.

[0146] Then, the ranging device 20 compares the value of Zr in the coordinates (Xr, Yr, Zr) obtained as a measurement result with the value of the set height h calculated in the calibration process. If the difference exceeds the specified threshold S1, it determines that the pixel includes the object 30, and selects the coordinates (Xr, Yr, Zr) of the measurement result corresponding to the pixel as the output object.

[0147] like Figure 9 As shown, in the ranging device 20 of this embodiment, for example, an object 30 placed on the ground FL is detected, and the distance information between the object 30 and the object is selected and output.

[0148] At this time, a threshold S1 is set as the threshold for detecting the object 30 placed on the ground FL.

[0149] Then, focusing on Zr of the ranging result (Xr, Yr, Zr) obtained from the orthogonal coordinate rotation, the difference (h-Zr) is calculated for each pixel of each pixel of the imaging element 23.

[0150] Here, when the difference (h-Zr)>S1, it is determined that there is an object 30 at the pixel position, and the distance information corresponding to the pixel is selected and output.

[0151] In the ranging device 20 of this embodiment, as described above, the distance information and angle information of the object 30 obtained by the TOF method are used to convert the measured distance information into an orthogonal coordinate rotation form. Then, the ranging device 20 compares the set height h with the Zr value, thereby distinguishing the position of an object whose height difference with the ground FL is more than a predetermined threshold S1 from the position of the ground where there is no object, and can detect the position of the object as a pixel where the object 30 exists.

[0152] Therefore, by selecting only the distance information corresponding to the pixels of the detected object 30 for output, and avoiding outputting unnecessary information such as the distance information of ground positions where there is no object 30, the amount of output data can be greatly reduced.

[0153] Next, regarding the case where the object detected using distance information, as described above, is a hole 130a formed in the ground FL, the following steps are taken: Figure 10 Please provide an explanation.

[0154] Here, as Figure 10 As shown, the hole 130a formed in the ground FL is detected, and only its ranging result is output.

[0155] Specifically, such as Figure 10 As shown, after determining the setting height h of the ranging device 20 through the above calibration process, the actual distance to the object (hole 130a) is measured.

[0156] That is, the distance is measured in the form of orthogonal coordinate rotation after rotating θ degrees around the X-axis, and the distance measurement results (Xr, Yr, Zr) of each pixel of the imaging element 23 are obtained.

[0157] At this time, in the ranging device 20, the threshold setting unit 17 sets a predetermined threshold S2 for detecting the hole 130a.

[0158] Then, the ranging device 20 compares the value of Zr among all the coordinates (Xr, Yr, Zr) of the pixels obtained as measurement results with the value of the set height h calculated in the calibration process. If the difference (h-Zr) is less than the specified threshold S2, it determines that the pixel includes a hole 130a, and selects the coordinates (Xr, Yr, Zr) of the measurement result corresponding to the pixel as the output object.

[0159] Therefore, as the state of the ground FL, it is easy to detect where there is a hole 130a, and only select the distance information corresponding to the pixel where the hole 130a is detected for output. This avoids outputting unnecessary information such as distance information to ground FL locations without holes 130a, and can significantly reduce the amount of output data.

[0160] Next, regarding the case where the object detected using distance information, as described above, is on a slope 130b where the height changes due to ground FL, the following steps are taken: Figure 11 Please provide an explanation.

[0161] Here, as Figure 11 As shown, the slope 130b, where the ground FL height changes, is detected, and only the distance measurement result is selected for output.

[0162] Specifically, such as Figure 11 As shown, after determining the setting height h of the distance measuring device 20 through the above calibration process, the actual distance to the object (slope 130b) is measured.

[0163] That is, the distance is measured in the form of orthogonal coordinate rotation after rotating θ degrees around the X-axis, and the distance measurement results (Xr, Yr, Zr) of each pixel of the imaging element 23 are obtained.

[0164] At this time, in the ranging device 20, the threshold setting unit 17 sets a predetermined threshold S3 for detecting the slope 130b.

[0165] Then, the ranging device 20 focuses on the value of Zr among the coordinates (Xr, Yr, Zr) of all pixels obtained as a measurement result, and calculates the change between adjacent top, bottom, left and right pixels (ΔZr / ΔXr) + (ΔZr / ΔYr).

[0166] Furthermore, if (ΔZr / ΔXr)+(ΔZr / ΔYr) is greater than the specified threshold S3, the ranging result corresponding to the pixel that detected slope 130b is selected and output.

[0167] Therefore, as the state of the ground FL, only the distance information corresponding to the pixels of the detected slope 130b is selected and output. This avoids outputting unnecessary information such as the distance information of ground FL positions without slope 130b, and can significantly reduce the amount of output data.

[0168] <Processing flow of the output control method>

[0169] The ranging device 20 of this embodiment utilizes the structure described above, according to... Figures 12 to 16 The flowchart shown illustrates the output control method.

[0170] That is, in Figure 12 As described above, a calibration process is performed as a stage before measuring the distance to the actual object 30.

[0171] In step S11, the distance calculation unit 11 of the ranging device 20 calculates the distance information based on the phase difference information of all pixels of the imaging element 23.

[0172] Next, in step S12, based on the distance information of each pixel calculated in step S11 and the angle information corresponding to each pixel obtained by the angle information acquisition unit 12, the three-dimensional coordinate transformation unit 13 converts the distance information into three-dimensional coordinates (X, Y, Z) in orthogonal coordinate form.

[0173] Next, in step S13, the plane detection unit 14 performs plane detection processing on a specified plane range on the ground FL where the ranging device 20 is installed.

[0174] Next, in step S14, the height calculation unit 15 calculates the angle θ formed by the Z-axis of the three-dimensional coordinates of the distance measuring device 20 and the perpendicular line to the ground FL (refer to...). Figure 6 ).

[0175] Next, in step S15, the coordinate rotation calculation unit 16 performs calculations on the coordinates (Xr, Yr, Zr) in the orthogonal coordinate rotation form in all pixels, which rotate the three-dimensional coordinates around the three axes by a specified angle θ.

[0176] Next, in step S16, the height calculation unit 15 calculates the average value of Zr within a specified plane range of the ground FL, and sets this value as the set height h.

[0177] In the ranging device 20 of this embodiment, as a pre-stage of measuring the distance to the actual object 30 through the above-described process, a calibration process is performed to set the setting height h of the ranging device 20, which is used as a reference for detecting the position of the object 30.

[0178] Then, in Figure 13 In the process of implementation Figure 12 After the calibration process shown, a procedure is performed to measure the distance to the actual object 30.

[0179] That is, in step S21, the distance calculation unit 11 uses the phase difference information obtained from all pixels of the imaging element 23 to calculate the distance information to the object corresponding to each of the multiple pixels.

[0180] Next, in step S22, the three-dimensional coordinate transformation unit 13 converts the distance information calculated in all pixels of the imaging element 23 into three-dimensional coordinates (X, Y, Z) in orthogonal coordinate form based on the angle information of each pixel obtained by the angle information acquisition unit 12.

[0181] Next, in step S23, the coordinate rotation calculation unit 16 rotates the three-dimensional coordinates corresponding to all pixels around the three axes X / Y / Z by a specified angle θ, and performs calculations on the rotated coordinates (Xr, Yr, Zr).

[0182] Next, in step S24, in order to check one by one whether each pixel of the imaging element 23 is a pixel with distance information as the output object, for example, to check from the lower left end of all pixels of the imaging element 23, i=0 and j=0 are set.

[0183] Next, in step S25, the Z-axis coordinate value Zr of the rotated pixel (i, j) is compared with the set height h, and the pixels that are determined to have a difference of more than or equal to the specified thresholds S1, S2, S3 set according to the object 30 being detected are selected as objects, and their coordinates (Xr, Yr, Zr) are saved.

[0184] It should be noted that the processing details for step S25 will be described in detail later because the types of objects 30 are different.

[0185] Next, in step S26, for i = i + 1, it is determined whether the adjacent pixels are pixels with distance information as output objects.

[0186] Next, in step S27, it is determined whether the condition i < Max_i is met. That is, in step S27, it is confirmed whether the pixels of the imaging element 23 have been verified from end to end in the horizontal direction.

[0187] Here, if it is determined that the horizontal end (MAX) has not yet been verified, the process returns to step S25 to verify whether the pixel has distance information as the output object. On the other hand, if it is determined that the horizontal end (MAX) has been verified, the process moves to step S28.

[0188] Next, in step S28, since the pixel that has been verified to the horizontal maximum position (end) has already been determined in step S27, i = 0 and j = j + 1 are set in order to move to the next column of pixels.

[0189] Next, in step S29, it is determined whether the condition j < Max_j is met. That is, in step S29, it is confirmed whether the pixels of the imaging element 23 have been verified from end to end in the vertical direction.

[0190] Here, if it is determined that the vertical end (MAX) has not yet been verified, the process returns to step S25 to verify whether the pixel has distance information as an output object. On the other hand, if it is determined that the vertical end (MAX) has been verified, the process moves to step S30.

[0191] Next, in step S30, since all pixels of the imaging element 23 have been verified, the coordinates (Xr, Yr, Zr) corresponding to the selected pixel are output according to the verification results in step S25.

[0192] Therefore, by selecting and outputting only the distance information corresponding to the pixels of the detected object 30, and avoiding outputting the distance information of all pixels corresponding to the ground FL position where there is no object 30, the amount of output data can be significantly reduced.

[0193] <The case where the detection object is object 30>

[0194] Here, regarding the above Figure 13 In step S25, the processing of whether each pixel of the imaging element 23 has distance information as the output object is verified, especially the processing when the object 30 is an object placed on the ground FL, is utilized. Figure 14 A detailed explanation will be provided.

[0195] That is, in step S31, from through Figure 12 The height h of the ground FL obtained from the calibration process is subtracted from the coordinate Zr value corresponding to the vertical direction of the orthogonal coordinate rotation system of the object pixel (i, j), and (h-Zr) is calculated.

[0196] Next, in step S32, in order to determine whether there is an object 30 placed on the ground FL, it is determined whether the result (h-Zr) of the subtraction process in step S31 is greater than the predetermined threshold S1 set by the threshold setting unit 17.

[0197] Here, when the result of the subtraction process (h-Zr) is determined to be greater than the threshold S1, the object 30 included in the identifiable object pixel is an object whose height dimension with respect to the ground FL is greater than the threshold, and the process proceeds to step S33.

[0198] On the other hand, when the result of the subtraction process (h-Zr) is determined to be smaller than the threshold S1, the object 30 included in the identifiable object pixel is an object with almost no height dimension from the ground FL or the ground FL, and proceed to step S35.

[0199] Next, in step S33, since the object 30 included in the object pixel has been identified in step S32 as an object whose height dimension with respect to the ground FL is above a threshold, the object detection unit 18 determines that there is an object 30 on the ground FL.

[0200] Next, in step S34, the output information selection unit 19 selects and determines the coordinates (Xr, Yr, Zr) of the object pixel (i, j) having the object 30 and its object ID (01) as the output object.

[0201] Next, in step S35, since it has been identified in step S32 that the object 30 included in the object pixel is an object with almost no height dimension with the ground FL or the ground FL, it is determined that there is no object at the position on the ground FL corresponding to the pixel, and proceed to step S26.

[0202] Therefore, by using the threshold S1 set to determine whether there is an object (object 30) placed on the ground FL, it is easy to determine whether the object pixel includes the object 30 placed on the ground FL.

[0203] <The case where the object of inspection is hole 130a>

[0204] Here, regarding the above Figure 13 In step S25, it is verified whether each pixel of the imaging element 23 has the processing of distance information as the output object, especially the object 30 is the hole 130a formed in the ground FL (refer to...). Figure 10 In the case of ), the following measures are taken: Figure 15 A detailed explanation will be provided.

[0205] That is, in step S41, from through Figure 12 The height h of the ground FL obtained from the calibration process is subtracted from the coordinate Zr value corresponding to the vertical direction of the orthogonal coordinate rotation system of the object pixel (i, j), and (h-Zr) is calculated.

[0206] Next, in step S42, in order to determine whether there is a hole 130a formed on the ground FL, it is determined whether the result (h-Zr) of the subtraction process in step S41 is smaller than the predetermined threshold S2 set by the threshold setting unit 17.

[0207] That is, when the object is hole 130a, the distance information of the corresponding pixel obtained by the ranging device 20 is greater than the set height h of the ground FL. Therefore, here, based on the fact that the value of (h-Zr) is negative in the pixel corresponding to hole 130a, it is determined whether it is smaller than the threshold S2 set for the determination.

[0208] Here, when it is determined that the result of the subtraction process (h-Zr) is less than the threshold S2, the object 30 included in the identifiable object pixel is a hole 130a under the ground FL, and the process proceeds to step S43.

[0209] On the other hand, when the result of the subtraction process (h-Zr) is greater than the threshold S2, the object 30 included in the identifiable object pixel is an object with almost no depth dimension with the ground FL or the ground FL, and proceed to step S45.

[0210] Next, in step S43, since it was determined in step S42 that the height dimension of the object 30 included in the object pixel and the ground FL is smaller than the threshold S2, the object detection unit 18 determines that there is a hole 130a in the ground FL.

[0211] Next, in step S44, the output information selection unit 19 selects the coordinates (Xr, Yr, Zr) of the object pixel (i, j) that has been determined to have a hole 130a and its object ID (02) as the output object.

[0212] Next, in step S45, since it has been identified in step S42 that the object included in the object pixel is an object with almost no depth dimension to the ground FL or the ground FL, it is determined that there is no hole 130a at the position on the ground FL corresponding to the pixel, and proceed to step S26.

[0213] Therefore, by using the threshold S2 set to determine whether there is a hole 130a formed in the ground FL, it is easy to determine whether the object pixel includes the hole 130a formed in the ground FL.

[0214] <The case where the test object is slope 130b>

[0215] Here, regarding the above Figure 13 In step S25, it is verified whether each pixel of the imaging element 23 has the processing of distance information as the output object, especially the object 30 being the slope 130b on the ground FL (refer to...). Figure 11 In the case of ), the following measures are taken: Figure 16 A detailed explanation will be provided.

[0216] That is, in step S51, in order to determine whether there is a slope 130b with a change in size in the height direction, the change in Zr of a certain pixel position (i, j) and the pixel position (i-1, j) adjacent to it on the horizontal negative side is calculated as ΔZr / ΔXr. In addition, the change in Zr of a certain pixel position (i, j) and the pixel position (i, j-1) adjacent to it on the vertical negative side is calculated as ΔZr / ΔYr.

[0217] Next, in step S52, in order to determine whether there is a slope 130b on the ground FL, it is determined whether the sum of ΔZr / ΔXr and ΔZr / ΔYr calculated in step S51 is greater than the predetermined threshold S3 set by the threshold setting unit 17, that is, whether the condition {(ΔZr / ΔXr)+(ΔZr / ΔYr)}>threshold S3 is satisfied.

[0218] That is, when the object is slope 130b, it is determined whether the sum of the vertical and horizontal changes in height of the pixels adjacent to it in the horizontal and vertical directions is greater than the threshold S3 set for the determination, based on the fact that the change in height of the pixels adjacent to it in the horizontal and vertical directions is greater than a predetermined value.

[0219] Here, when the determination result is greater than the threshold S3, it can be identified that there is a possibility that the object 30 included in the object pixel is slope 130b, and proceed to step S53.

[0220] On the other hand, when the determination result is less than the threshold S3, it can be identified that the object pixel does not include ramp 130b, and proceed to step S57.

[0221] Next, in step S53, the change in Zr, ΔZr / ΔX, between a pixel position (i, j) and its adjacent pixel position (i+1, j) on the horizontal positive side is calculated. Furthermore, the change in Zr, ΔZr / ΔYr, between a pixel position (i, j) and its adjacent pixel position (i, j+1) on the vertical positive side is calculated.

[0222] Next, in step S54, it is determined whether the sum of ΔZr / ΔXr and ΔZr / ΔYr calculated in step S53 is greater than the threshold S3, that is, whether the condition {(ΔZr / ΔXr)+(ΔZr / ΔYr)}>S3 is satisfied.

[0223] Here, when the determination result is greater than the threshold S3, the object 30 included in the object pixel can be identified as slope 130b, and the process proceeds to step S55.

[0224] On the other hand, when the determination result is less than the threshold S3, it can be identified that the object pixel does not include the ramp 130b, and proceed to step S57.

[0225] Next, in step S55, since it was determined in step S54 that the sum of ΔZr / ΔXr and ΔZr / ΔYr is greater than the threshold S3, the object detection unit 18 determines that there is a slope 130b on the ground FL.

[0226] Next, in step S56, the output information selection unit 19 selects the coordinates (Xr, Yr, Zr) of the object pixel (i, j) that has been determined to have a slope 130b and its object ID (03) as the output object.

[0227] Next, in step S57, since it was determined in step S54 that the sum of ΔZr / ΔXr and ΔZr / ΔYr is smaller than the threshold S3, it can be identified that the size of the object in the height direction hardly changes between adjacent pixels, so it is determined that there is no slope on the ground, and proceed to step S26.

[0228] Therefore, by using the threshold S3 set to determine whether there is a slope 130b on the ground FL, it is easy to determine whether the object pixel includes the slope 130b set on the ground FL.

[0229] <Detection and processing of the condition of ground FL>

[0230] As described above, the ranging device 20 of this embodiment can determine whether an object (object, hole, slope, etc.) is included by using distance information for all pixels included in the imaging element 23, and can output only the distance information of the object pixels that include the object.

[0231] Furthermore, the ranging device 20 of this embodiment is further improved by continuous implementation. Figures 14 to 16 The flowchart can also detect the status of the ground FL.

[0232] Specifically, targeting Figure 13 The process of step S25 is carried out continuously. Figures 14 to 16 The flowchart shown illustrates how, by using three thresholds S1, S2, and S3 as the state of the ground FL, it is possible to detect the presence of objects, holes, slopes, etc.

[0233] Therefore, firstly, according to Figure 14 The flowchart shown uses threshold S1 for judgment processing. If an object with a height dimension is detected on the ground FL, it can be determined that an object 30 is placed on the ground FL. If no object is detected, then... Figure 15 The flowchart shown is used for judgment and processing.

[0234] Then, according to Figure 15 The flowchart shown uses threshold S2 for judgment processing. If a hole 130a with a depth dimension is detected in the ground FL, it can be determined that a hole 130a has formed in the ground FL. If no hole 130a is detected, then... Figure 16 The flowchart shown is used for judgment and processing.

[0235] Finally, according to Figure 16The flowchart shown uses threshold S3 to perform the determination process. If slope 130b is detected on the ground FL, it can be determined that there is slope 130b on the ground FL. If slope 130b is not detected, the state detection process of the ground FL ends and proceeds to step S26.

[0236] Therefore, by using different thresholds S1, S2, and S3 to perform judgment processing, for example, when the ranging device 20 is mounted on a conveyor that can travel on the ground FL, it is also possible to accurately determine whether there are unevennesses such as holes 130a or obstacles on the ground FL, and to smoothly carry out the conveying operation.

[0237] [Other Implementation Methods]

[0238] The above description pertains to one embodiment of the present invention, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention.

[0239] (A)

[0240] In the above embodiments, examples of implementing the present invention have been described as output control devices and output control methods. However, the present invention is not limited thereto.

[0241] For example, the output control method of the above-described output control device can also be implemented as an output control program executed on a computer to realize the present invention.

[0242] The program is stored in the memory (storage unit) mounted on the output control device. The CPU reads the output control program stored in the memory and executes each step in the hardware. More specifically, the CPU reads the output control program and executes the distance information acquisition step and the output information selection step described above, thereby achieving the same effect as described above.

[0243] Alternatively, the present invention can also be implemented as a storage medium for storing the output control program of the output control device.

[0244] (B)

[0245] In the above embodiments, a distance calculation unit 11, which calculates the distance information corresponding to each pixel of the distance image in a Time-of-Flight (TOF) manner, has been described as an example of a distance information acquisition unit. However, the present invention is not limited thereto.

[0246] For example, it could also be a structure that obtains distance information corresponding to each pixel of a distance image by using a Time-of-Flight (TOF) method from an external ranging device.

[0247] That is, the output control device and the ranging device of the present invention can also be set separately, and the distance information is obtained from the ranging device and the distance information corresponding to the pixel as the output object is selected for output.

[0248] (C)

[0249] In the above embodiment, an example of calculating the installation angle θ of the ranging device 20 was given. However, the present invention is not limited thereto.

[0250] For example, if the installation angle of the ranging device is known in advance, the structure such as the setting height can be determined using that installation angle θ.

[0251] (D)

[0252] In the above embodiments, examples of detecting reflected light from the lighting device 21 directed at the object and measuring the distance to the object have been described. However, the present invention is not limited thereto.

[0253] For example, the structure could be as follows: in addition to irradiating the object with light in the general sense (ultraviolet light / visible light / infrared light), the illumination device also irradiates the object with electromagnetic waves such as γ (gamma) rays with wavelengths shorter than light, X-rays, microwaves with wavelengths longer than light, and radio waves (shortwave, medium wave, long wave), and detects the reflection, thereby measuring the distance to the object.

[0254] That is, the light irradiated onto the object can also be other electromagnetic waves that have the property of attenuation inversely proportional to the square of the distance.

[0255] (E)

[0256] In the above embodiments, objects placed on the ground FL, holes 130a, and slopes 130b were used as examples for detection using distance information. However, the present invention is not limited thereto.

[0257] For example, the detectable object can also be any object other than those mentioned above.

[0258] In this case, the presence or absence of each object can be detected by using thresholds set according to the shape, size, and form of each object.

[0259] Industrial applicability

[0260] The ranging device of the present invention has the effect of reducing the amount of data containing the distance information output, and therefore can be widely used, for example, in ranging devices such as TOF sensors.

[0261] Explanation of reference numerals in the attached figures

[0262] 10 Control unit (output control device); 11 Distance calculation unit (distance information acquisition unit); 12 Angle information acquisition unit; 13 Three-dimensional coordinate transformation unit; 14 Plane detection unit; 15 Height calculation unit; 16 Coordinate rotation calculation unit; 17 Threshold setting unit; 18 Object detection unit; 19 Output information selection unit; 20 Distance measuring device; 20a Main body; 21 Illumination device; 22 Light receiving lens; 23 Imaging element; 25 Storage unit; 26 Output unit; 30 Object; 130a Hole; 130b Slope; D Distance; FL Ground; L1 Light; P1 Support.

Claims

1. An output control device for controlling the output of information contained in a distance image including distance information to an object, characterized in that it has: The distance information acquisition unit acquires distance information to the object based on the amount of electromagnetic waves reflected from the lighting device toward the object. The output information selection unit selects distance information corresponding to pixels of the distance image as the output object, the distance image including the object detected based on the distance information acquired in the distance information acquisition unit; An angle information acquisition unit acquires angle information corresponding to each pixel contained in the distance image; A three-dimensional coordinate transformation unit, which transforms the distance information obtained by the distance information acquisition unit into three-dimensional coordinates based on the angle information obtained by the angle information acquisition unit; A planar detection unit that detects the ground on which the object is placed; The height calculation unit calculates the setting height of the ranging device based on the three-dimensional coordinates converted from the distance information of the ground detected in the plane detection unit in the three-dimensional coordinate transformation unit; The coordinate rotation calculation unit calculates the rotation coordinates after the three-dimensional coordinates, which have been transformed in the three-dimensional coordinate transformation unit according to the distance information and the angle information, are rotated around the axis. The object detection unit compares the height coordinate of the rotation coordinate calculated in the coordinate rotation calculation unit with the set height calculated in the height calculation unit, and detects the object as the object when it detects an object with a height dimension. The threshold setting unit sets a first threshold, a second threshold, and a third threshold as predetermined thresholds used when the object detection unit detects the object. The height calculation unit calculates the average of the vertical coordinate values ​​obtained by rotating the orthogonal coordinate system of the ranging device around its axis around the angle formed by the perpendicular line to the ground detected by the plane detection unit and the optical axis of the ranging device, and uses this average as the set height. The object detection unit determines that an object exists on the ground if its size in the height direction above the ground is greater than the first threshold, determines that a hole exists on the ground if its size in the height direction above the ground is less than the second threshold, and determines that a slope exists on the ground if the change in size of an adjacent pixel in the height direction above the ground is greater than the third threshold.

2. The output control device as described in claim 1, characterized in that, The output information selection unit selects and outputs distance information for each pixel, including the object detected by the object detection unit.

3. A ranging device, characterized in that, have: The output control device as described in claim 1 or 2; A lighting device that irradiates electromagnetic waves onto the object; The light-receiving part detects the amount of electromagnetic waves reflected from the lighting device.

4. The ranging device as described in claim 3, characterized in that, It also has a storage unit that stores at least one of the following: the distance information, the angle information corresponding to each pixel included in the distance image, the orthogonal coordinate system of the ranging device, the set height, the rotation coordinates after rotating the three-dimensional coordinates converted according to the distance information and the angle information around the axis, the threshold used when detecting the object, and the coordinate values ​​of the pixels that are the output objects.

5. The ranging device as described in claim 3 or 4, characterized in that, It also has an output unit that outputs the distance information corresponding to the pixel selected in the output information selection unit to an external device.

6. An output control method for controlling the output of information contained in a distance image that includes distance information to an object, characterized in that it has: The distance information acquisition step obtains distance information to the object based on the amount of electromagnetic waves reflected from the lighting device to the object. The output information selection step selects distance information corresponding to pixels of the distance image as the output object, wherein the distance image includes the object detected based on the distance information obtained in the distance information acquisition step; The angle information acquisition step acquires the angle information corresponding to each pixel contained in the distance image; The three-dimensional coordinate transformation step converts the distance information obtained in the distance information acquisition step into three-dimensional coordinates based on the angle information obtained in the angle information acquisition step. The planar detection step involves detecting the ground on which the object is placed; The height calculation step calculates the set height of the ranging device based on the three-dimensional coordinates converted from the distance information of the ground detected in the plane detection step in the three-dimensional coordinate transformation step. The coordinate rotation calculation step calculates the rotation coordinates of the three-dimensional coordinates after they have been rotated around the axis in the three-dimensional coordinate transformation step based on the distance information and the angle information. The object detection step compares the height coordinate of the rotation coordinate calculated in the coordinate rotation calculation step with the set height calculated in the height calculation step. When an object with a height dimension is detected, the object is detected as the object. The threshold setting step sets a first threshold, a second threshold, and a third threshold as predetermined thresholds used when the object detection step detects the object. The height calculation step calculates the average of the vertical coordinate values ​​obtained by rotating the orthogonal coordinate system of the ranging device around its axis in the plane detection step to the angle formed by the perpendicular line from the ground detected in the plane detection step and the optical axis of the ranging device. This average is used as the set height. The object detection step determines that an object exists on the ground if its dimension in the height direction above the ground is greater than the first threshold, determines that a hole exists on the ground if its dimension in the height direction above the ground is less than the second threshold, and determines that a slope exists on the ground if the change in dimension of adjacent pixels in the height direction above the ground is greater than the third threshold.

7. An output control program that controls the output of information contained in a distance image including distance information to an object, characterized in that, The steps of the output control method according to claim 6 are executed in a computer.

Images