JP5900722B2 - Scanning distance measuring device signal processing device, signal processing method, and scanning distance measuring device - Google Patents

Description

  The present invention relates to a signal processing device, a signal processing method, and a scanning method of a scanning distance measuring device that scans measurement light toward a monitoring target region and detects reflected light from an object with respect to the measurement light at every predetermined scanning angle. The present invention relates to a distance measuring device.

  A scanning rangefinder that employs at least one of the TOF (Time of Flight) method and AM (amplitude modulation) method is used for the visual sensors of robots and automated guided vehicles, door opening / closing sensors, and monitoring target areas. It is used as a monitoring sensor that detects the presence or absence of an intruder, and a safety sensor that detects a person or an object approaching a dangerous device and stops the machine safely.

As disclosed in Patent Document 1, the TOF method is based on a scanning measurement based on a detection time difference Δt between a pulsed measurement light output toward a monitoring target region and a reflected light from an object with respect to the measurement light. This is a method for calculating the distance D from the distance device to the object existing in the monitoring target area, and the distance D is calculated using the following mathematical formula. In the formula, C is the speed of light.
D = Δt · C / 2

As disclosed in Patent Document 2, the AM method is based on the phase difference Δφ between the measurement light whose amplitude is modulated and output toward the monitoring target area and the reflected light from the object with respect to the measurement light. In this method, the distance D from the scanning distance measuring device to the object existing in the monitoring target area is calculated, and the distance D is calculated using the following equation. In the equation, C is the speed of light and f is the modulation frequency.
D = Δφ · C / (4π · f)

  Further, by adopting both the TOF method and the AM method and outputting the amplitude-modulated measurement light in a pulse shape, a long distance of one wavelength or more of the amplitude-modulated light is calculated by the TOF method, and one of the amplitude-modulated light A burst modulation type scanning distance measuring device that calculates a distance shorter than the wavelength by the AM method has also been proposed.

  Further, Patent Document 3 discloses an object detection system that detects the position of an object by irradiating a target region using a laser sensor and processing the obtained distance measurement data with a processing device. And background data acquisition means for acquiring information of an object corresponding to the background of the area, and position detection for detecting the position of the object by acquiring time-dependent distance measurement data of the object in the area by the laser sensor. An object detection system comprising means and object detection means for detecting the position of the object in the region has been proposed.

  In any case, the signal processing device of the scanning rangefinder has a predetermined correlation between the measurement light and the reflected light, for example, a correlation found between the delay time or phase difference between the two and the distance. And a distance calculation unit that calculates a distance from the scanning distance measuring device to an object existing in the monitoring target area for each predetermined scanning angle.

  Further, in Patent Document 4, irradiation light pulse-modulated at a certain frequency is irradiated onto an object, and the reflected light is received by a light receiving element such as a PSD (Position Sensing Device), and photoelectric generated according to the light receiving position. A distance measuring device using the principle of triangulation has been proposed that measures the distance to an object based on a converted signal. It is also possible to use a two-dimensional imaging device instead of PSD (Position Sensing Device).

JP 2007-256191 A JP 2002-90454 A JP 2009-85927 A Japanese Patent Laid-Open No. 06-288774

  However, it is not easy to accurately determine whether or not there is a monitoring target in the monitoring target area based on the reflected light from the object in any scanning rangefinder that employs any method. There was a problem that there was a risk of false detection.

  For example, if the reflected light from minute dust floating in the monitored area or the minute insect flying around in the monitored area is mistaken as reflected light from the monitored object, or installed in the monitored area There is a possibility that measurement light from another scanning distance measuring device may be mistaken as reflected light from the monitoring object.

  Furthermore, when the monitoring target area is partitioned outdoors, there is a possibility that reflected light from leaves, raindrops, and the like may be mistaken for reflected light from the monitoring target.

  Therefore, when an object is continuously detected along the scanning direction of the measurement light by a predetermined width or more, in other words, when it is continuously detected by a predetermined angle or more, it is determined that the object is an object to be monitored. It is conceivable to recognize less than the object as noise and exclude it from the determination target of the presence or absence of the monitoring target.

  However, if there is a noise source such as a small insect near the scanning rangefinder, some or all of the monitored object that may be behind it is hidden behind the noise source and exceeds the specified width. There is a problem that it may not be recognized as an object.

  This will be specifically described. 11 (a) and 11 (b), the measurement light is repeatedly scanned at a predetermined period toward the fan-shaped monitoring target region set at a predetermined distance from the scanning distance measuring device 1, and the scanning angle θ An explanatory diagram in the case of detecting a monitoring object of the size of a human arm by detecting reflected light from an object with respect to measurement light every time is shown. In the figure, the hatched large circle is the monitoring object T, and the small black circle is a minute object that becomes noise. Reference numerals 11, 21, 31,. ")").

  In the lower part of FIGS. 11A and 11B, if the same distance is calculated twice in the scanning angle direction on the far side, it is determined that the monitoring object is “present”, and the scanning angle direction is on the near side. If the same distance is calculated three times in succession, the determination result when determining that the monitoring object is “present” is displayed in a table.

  In the table, columns of “measurement result”, “continuous number”, and “monitoring object determination result” for each scanning angle direction are provided. In the “Measurement result” column, when the distance to the object is the distance in the monitoring target area and the distance to the minute object located in the vicinity of the scanning distance measuring device, “Near”, the scanning distance measurement “Far” is indicated when the distance is to the monitoring target T located on the far side of the apparatus, and “None” is indicated when the distance is outside the monitoring target area or the distance is not calculated. In the “continuous number” column, the number of “far” or “near” continuous along the scanning direction is written. In the “monitoring object determination result” column, either “Yes” or “No” determination result is written.

  In the situation shown in FIG. 11A, it can be determined that the monitoring target T exists on the far side of the scanning distance measuring device, but in the situation shown in FIG. 11B, the far side of the scanning distance measuring device. It cannot be determined that the monitoring target T exists on the side. This is because the continuity of the far-side monitoring target T is impaired by the minute object located on the near side.

  When the scanning distance measuring device is used as a safety sensor, the control device of the machine detects the monitoring object in the monitoring object region based on the monitoring object detection signal output from the scanning distance measuring device. If it is determined that the machine has been stopped, it is necessary to automatically stop the machine for safety. However, such a misrecognition causes an inconvenient situation that the monitoring target detection signal may not be output from the scanning distance measuring device.

  In view of the above-described problems, an object of the present invention is to provide a signal processing device, a signal processing method, and a scanning for a scanning distance measuring device that can appropriately detect a monitoring target behind an object that is a noise source. It is in the point which provides a type distance measuring device.

  In order to achieve the above-described object, the first characteristic configuration of the signal processing device of the scanning distance measuring device according to the present invention is to measure toward the monitoring target area as described in claim 1 of the document of the claims. A signal processing device of a scanning distance measuring device that scans light and detects reflected light from an object with respect to measurement light at each predetermined scanning angle, wherein the measurement light and reflected light are detected at each predetermined scanning angle. A distance calculation unit that calculates a distance from the scanning distance measuring device to the object based on a predetermined correlation between the distance measurement unit and the distance data that is calculated by the distance calculation unit and indicates the inside of the monitoring target area When there is a plurality of scanning angle directions, a group in which the plurality of distance data are collected is generated, and any value from the average value or median value of the distance data included in the group to the maximum value of the distance data The representative of the group A group generation processing unit to be set apart, and the number of distance data included in the group generated by the group generation processing unit or the object detection width defined by the maximum scanning angle is preset according to the representative distance When the number of objects indicating the minimum width of the object detection is greater than or equal to the scan angle or more than the scanning angle, the monitoring object determination unit that determines that the monitoring object exists and the determination result of the monitoring object determination unit determine that the monitoring object exists And a signal output unit that outputs a monitoring object detection signal indicating that when it is done.

  When reflected light corresponding to the measurement light that scans within the monitoring target area is detected by the scanning distance measuring device, the scanning angle is calculated by the distance calculation unit based on a predetermined correlation between the measurement light and the reflected light. A distance is calculated every time. When no object exists in a certain scanning angle direction, the reflected light is not detected, and the distance is not calculated at the scanning angle.

  If the distance calculated by the distance calculation unit is a value indicating the monitoring target area, the corresponding object exists in the monitoring target area. If such a distance exists in a plurality of adjacent scanning angle directions, it can be assumed that an object of a certain size exists. Naturally, even for objects of the same size, the number of scanning angles detected continuously in the vicinity of the scanning distance measuring device is large, and it is detected continuously in the distance of the scanning distance measuring device. The number of scanning angles to be reduced is reduced.

  Therefore, a plurality of distance data indicating such a relationship are grouped together by the group generation processing unit, and any one of an average value or median value of the distance data included in the group to a maximum value of the distance data is included. The value is set to the group's representative distance.

  Then, the object detection width defined by the number of distance data included in the group or the maximum scanning angle, that is, the size of the object along the scanning direction is set in advance according to the representative distance by the monitoring object determination unit. When the number is equal to or greater than the number indicating the minimum object detection width or equal to or greater than the scanning angle, it is determined that the monitoring target exists. A group in which distance data less than the number indicating the minimum object detection width or less than the scanning angle is collected is determined not to be an object to be monitored but to be noise.

  If the object existing in the monitoring target area is minute dust, insects, or raindrops, the probability that the distance is continuously calculated in the adjacent scanning angle direction becomes very small. In view of this, it is possible to determine that the monitoring target exists when the substantially equal distance data is continuously calculated in the scanning angle direction continuous with a certain width. However, in this case, if there is some other object behind a small object as a noise source located in the vicinity when viewed from the scanning distance measuring device, the continuity of the other object behind is interrupted by the small object in the vicinity. Therefore, there is a possibility that another object behind may not be determined as the monitoring target.

  In the signal processing apparatus having the first characteristic configuration described above, the distance data continuously calculated at the scanning angles that are continuous along the scanning direction are grouped regardless of the value. An inconvenient situation in which the continuity of an object is interrupted by a small object in the vicinity does not occur. In addition, the representative distance of the group for determining whether or not it is a monitoring object is set to any value from the average value or median value of a plurality of distance data in the group to the maximum value of the distance data. Therefore, it is possible to determine the minimum object detection width with an emphasis on the far side rather than the near side when viewed from the scanning distance measuring device.

  According to the second characteristic configuration, as described in claim 2, the scanning type distance measuring device that scans the measurement light toward the monitoring target region and detects the reflected light from the object with respect to the measurement light at every predetermined scanning angle. A signal processing device of the apparatus, wherein the distance calculation unit calculates the distance from the scanning distance measuring device to the object based on a predetermined correlation between the measurement light and the reflected light for each predetermined scanning angle And when the distance data calculated by the distance calculation unit and indicating the inside of the monitoring target area exists in a plurality of adjacent scanning angle directions, the difference between the distance data in the adjacent scanning angle directions is a first threshold value. A group in which a plurality of distance data items are collected is generated, and one of the values from the average value or median value of the distance data included in the group to the maximum value of the distance data is set as the representative distance of the group. Group generation processing And the number of distance data included in the group generated by the group generation processing unit or the object detection width defined by the maximum scanning angle is equal to or greater than the number indicating the minimum object detection width preset according to the representative distance. Or, when the angle is equal to or larger than the scanning angle, as a result of determination by the monitoring object determination unit that determines that the monitoring object exists and the monitoring object determination unit for a plurality of adjacent groups, it is not determined that the monitoring object exists. If this is the case, a new group is created by combining two adjacent groups, and any value from the average value or median value of the distance data included in the new group to the maximum value of the distance data is set. A group integration processing unit to be set as a representative distance of a new group, and a group generated by the group generation processing unit or the group integration processing unit As a result of the determination by the monitoring object determination unit, when it is determined that there is a monitoring object, a signal output unit that outputs a monitoring object detection signal indicating that, the group integration processing unit, The point is that two adjacent groups having the maximum number of distance data are collected to generate one new group.

  In the signal processing device having the second characteristic configuration, the distance data calculated by the distance calculation unit is a value indicating the monitoring target area, exists in a plurality of adjacent scanning angle directions, and is adjacent. When the three conditions that the difference in the distance data in the scanning angle direction is equal to or less than the first threshold are satisfied, the group generation processing unit groups the plurality of distance data. Then, similarly to the first feature configuration, it is determined by the monitoring object determination unit whether or not the monitoring object exists.

  However, if there is some other object behind a small object as a noise source located in the vicinity when viewed from the scanning distance measuring device, the continuity of the other object behind is interrupted by the nearby small object. Another object behind is generated as a plurality of groups by the group generation processing unit. When the object detection minimum width is determined for each group by the monitoring object determination unit, another object behind may not be determined to be the monitoring object.

  Therefore, in such a case, the group integration processing unit generates one new group that combines two adjacent groups, and calculates the distance data from the average value or median value of the distance data included in the new group. Any value up to the maximum value is set as the representative distance of the new group. By determining the minimum object detection width for the group thus integrated by the monitoring object determination unit, the presence / absence of the monitoring object is appropriately determined.

  Of the plurality of groups generated by the group generation processing unit, when groups adjacent to a certain group exist on both sides along the scanning direction, the sum of the number of distance data constituting the two adjacent groups is maximized. By integrating the groups and generating one new group, the presence or absence of the monitoring object is properly determined on the safety side.

In the third feature configuration, as described in claim 3, in addition to the first or second feature configuration described above, a maximum value of distance data included in the group is set as the representative distance. In the point.

  If the maximum value of the distance data included in the group is set as the representative distance, irradiation of the measuring light to the object located on the far side of the scanning distance measuring device at a certain scanning angle is blocked by the minute object on the near side. In this case, it is possible to determine an appropriate object detection minimum width corresponding to the distance of an object located far away.

The fourth characterizing feature of the can, as noted in the claim 4, in addition the first above the third one characteristic feature of the value indicating the object detection minimum width is smaller as the representative distance increases It is in the point set to become.

  As already explained, even for objects of the same size, the number of scanning angles detected continuously in the vicinity of the scanning distance measuring device is large, or the maximum scanning angle is large, and the scanning distance measuring device is far away. Then, the number of scanning angles detected continuously is small, or the maximum scanning angle is small. Therefore, if the value indicating the minimum object detection width is reduced as the representative distance of the group becomes longer, the object that is present at any position in the near or near position with respect to the scanning distance measuring device is properly monitored. It becomes possible to determine whether or not.

As described in the fifth aspect of the present invention, the scanning distance measuring device according to the present invention incorporates the signal processing device of the scanning distance measuring device having any one of the first to fourth characteristics described above. Therefore, it is possible to realize a scanning distance measuring device that can appropriately detect a monitoring object to be truly detected.

According to the first characteristic configuration of the signal processing method of the scanning distance measuring device according to the present invention, as described in the sixth aspect , the measurement light is scanned toward the monitoring target region, and the measurement light is scanned at every predetermined scanning angle. A signal processing method of a scanning distance measuring device for detecting reflected light from an object, wherein the scanning distance measurement is performed based on a predetermined correlation between measurement light and reflected light at each predetermined scanning angle. A distance calculating step for calculating a distance from the apparatus to the object; and distance data calculated in the distance calculating step and indicating the monitoring target area in a plurality of adjacent scanning angle directions. A group generation processing step for generating a group in which the distance data is collected and setting any value from the average value or median value of the distance data included in the group to the maximum value of the distance data as the representative distance of the group The number of distance data included in the group generated in the group generation processing step or the object detection width defined by the maximum scanning angle is equal to or greater than the number indicating the minimum object detection width preset according to the representative distance, or When it is determined that there is a monitoring object as a result of the determination of the monitoring object determining step that determines that the monitoring object exists and the monitoring object determining step when the scanning angle is greater than or equal to the scanning angle, this is indicated. And a signal output step for outputting a monitoring object detection signal.

In the second characteristic configuration, as described in the seventh aspect , the scanning-type distance measuring device that scans the measurement light toward the monitoring target region and detects the reflected light from the object with respect to the measurement light at every predetermined scanning angle. A signal processing method for an apparatus, wherein a distance calculation step of calculating a distance from the scanning distance measuring device to an object based on a predetermined correlation between measurement light and reflected light for each predetermined scanning angle And the distance data calculated in the distance calculation step and indicating the inside of the monitoring target area exists in a plurality of adjacent scanning angle directions, the difference between the distance data in the adjacent scanning angle directions is a first threshold value. A group in which a plurality of distance data items are collected is generated, and one of the values from the average value or median value of the distance data included in the group to the maximum value of the distance data is set as the representative distance of the group. group The object detection width defined by the number of distance data included in the group generated in the group generation processing step and the group generation processing step or the maximum scanning angle is a predetermined object detection minimum width according to the representative distance. As a result of the determination of the monitoring object determination step that determines that the monitoring object is present and the monitoring object determination step for a plurality of adjacent groups when the number is greater than or equal to the indicated number or the scanning angle, the monitoring object is present. If it is not determined, a new group is created by combining two adjacent groups, and either the average value or the median value of the distance data included in the new group to the maximum value of the distance data. A group integration processing step for setting the value of a new group representative distance, the group generation processing step or the group A signal output step of outputting a monitoring object detection signal indicating that when it is determined that the monitoring object exists as a result of the determination of the monitoring object determination step for the group generated in the group integration processing step; , wherein the group integrating process step, Ru near the point where the number of distance data to generate one new group together two adjacent groups of the maximum.

  As described above, according to the present invention, the signal processing device, the signal processing method, and the scanning measurement of the scanning distance measuring device that can appropriately detect the monitoring target existing behind the object that becomes the noise source. A distance device can be provided.

1 is a schematic longitudinal sectional view showing the overall configuration of a scanning distance measuring device according to the present invention. Overall functional block diagram including a signal processing device incorporated in a scanning distance measuring device Functional block configuration diagram showing first and third aspects of a signal processing device configured by a signal processing unit and a system control unit Flowchart explaining overall processing executed by signal processing apparatus Explanatory drawing which shows the 1st aspect of a signal processing apparatus, and shows the processing content by a group production | generation process part Functional block diagram showing a second aspect of the signal processing apparatus Explanatory drawing which shows the 2nd aspect of a signal processing apparatus, and shows the processing content by a group production | generation process part and a group integration process part (A), (b), (c) shows the 2nd aspect of a signal processing apparatus, the description which shows the processing content by a group production | generation process part and a group integration process part, (d) is the 3rd of a signal processing apparatus. Explanatory drawing which shows the mode and shows the processing content by the group generation processing unit Explanatory drawing of the principle which can calculate a plurality of distances in the same operation angle direction, which is a precondition of the third aspect of the signal processing device Explanatory drawing of the 1st and 2nd polarizing mirror which shows another embodiment Illustration of prior art

  Hereinafter, a signal processing device, a signal processing method, and a scanning distance measuring device of a scanning distance measuring device according to the present invention will be described with reference to the drawings. In the following example, an infrared semiconductor laser is used as a light source for measurement light, a signal processing device including a distance calculation unit that calculates a distance to an object by the TOF method is incorporated, and scanning measurement is used as a safety sensor. The distance device will be described.

  When the scanning distance measuring device detects an obstacle of a certain size such as an intruder or a transport vehicle as a monitoring target in a preset monitoring target area, a signal to that effect is output to the external device. Based on the signal, the external device performs predetermined control such as stopping the device for safety.

  It should be noted that the present invention can also be applied to a scanning distance measuring apparatus that uses other types of light sources such as lasers and LEDs other than semiconductor lasers. The present invention can also be applied to a distance calculation unit that employs a method other than the TOF method as a distance calculation method, such as an AM method or a burst modulation method that employs both the TOF method and the AM method. Furthermore, the reflected light is received by a light receiving element such as a PSD (Position Sensing Device) or a CMOS type two-dimensional image sensor, and the distance to the object is measured based on a photoelectric conversion signal generated according to the light receiving position. The present invention can also be applied to a distance measuring device using the principle of triangulation.

  FIG. 1 illustrates such a scanning distance measuring device. The scanning distance measuring apparatus 1 includes a cylindrical casing 2 that houses a pair of light projecting units 3 and a light receiving unit 5, and an arcuate optical window 2 a that is disposed along the circumferential direction of the casing 2. The first deflection mirror 9 that deflects and reflects the measurement light output from 3 in a direction orthogonal to the axis P of the cylindrical casing, and the first deflection mirror 9 that deflects and reflects the reflected light from the object to be measured T toward the light receiving unit 5. A deflection optical system 4 that rotates the two deflection mirrors 10 about the axis P and rotationally scans the measurement light on a plane orthogonal to the axis P is provided.

  The inner wall surface of the casing 2 is covered with a light-absorbing member such as a dark screen that absorbs stray light, and a deflection optical system 4 is disposed between the light projecting unit 3 and the light receiving unit 5 that are disposed to face each other along the axis P. .

  The light projecting unit 3 includes a light emitting element formed of an infrared semiconductor laser and an optical lens that forms a light beam output from the light emitting element into parallel light, and is fixed to the inside of the upper wall of the casing 2.

  The light receiving unit 5 includes a light receiving element made of an avalanche photodiode that detects reflected light, and is fixed on a support plate on a hollow shaft 13 fixed to the casing 2.

  The deflection optical system 4 includes a top surface 8b to which the first deflection mirror 9 and the second deflection mirror 10 are attached, and a cylinder having a peripheral wall portion 8a to which a light receiving lens 14 for condensing reflected light by the light receiving portion 5 is attached. And a motor 11 that rotationally drives the rotating body 8 in one direction.

  The rotating body 8 whose lower end portion is reduced in diameter is rotatably supported by the hollow shaft 13 via a bearing 12 provided on the inner peripheral surface thereof, and a magnet 11b serving as a rotor of the motor 11 on the outer peripheral surface of the reduced diameter portion. Is attached. The motor 11 is composed of the rotor and a stator composed of a coil 11 a disposed so as to face the rotor, and a cover of the stator is attached to a hollow shaft 13 fixed to the casing 2.

  The measurement light emitted from the light projecting unit 3 along the optical axis L1 is deflected by the first deflection mirror 9 to the optical axis L2 orthogonal to the optical axis L1, passes through the optical window 2a, and toward the measurement target space. Irradiated. The reflected light from the measurement object T existing in the measurement target space passes through the optical window 2a along the optical axis L3 parallel to the optical axis L2 and enters the light receiving lens 14, and is reflected by the second deflection mirror 10. The light is deflected to an optical axis L4 orthogonal to the axis L3 and condensed on the light receiving unit 5.

  The measurement light deflected by the first deflection mirror 9 passes through the upper region of the optical window 2a, and the reflected light from the object T passes through the lower region of the optical window 2b.

  A range in which the measurement light is scanned into the measurement object space via the optical window 2a by the deflection optical system 4 that is rotationally driven by the motor 11, specifically, an angular range of about 270 degrees with respect to the axis P described above. Is a scanning angle region for measurement, and an angular region where the measurement light is blocked by the casing 2 and is not emitted to the measurement target space is a non-measuring scanning angle region.

  That is, the deflection optical system 4 constitutes a scanning unit that periodically deflects and scans the measurement light output from the light projecting unit 3 into the measurement target space through the optical window 2a.

  As shown in FIG. 10, the first polarizing mirror 9 and the second polarizing mirror 10 may be integrally formed of resin or optical glass. In this example, the first deflection mirror 91 is configured to deflect the measurement light 90 degrees toward the measurement target region with respect to the optical axis L1 by the first deflection surface 91, and the reflected light is reflected by the second deflection surface 92 to the optical axis L4. The second deflection mirror 10 is configured to deflect 90 degrees toward the light receiving unit 5 along the axis.

  The central portion of the upper end side of the second deflection surface 92 is cut out, and the first deflection mirror 9 is formed to extend in the cutout portion 95. By adopting such a configuration, the apparatus can be reduced in size.

  A disc-shaped slit plate 15a having a plurality of slits formed in the circumferential direction is attached to the peripheral wall portion 8a of the rotating body 8, and a photo interrupter 15b for detecting the slit is attached to the inner wall of the casing 2 and deflected by these. A scanning angle detector 15 that detects the scanning angle of the optical system 4 is configured.

  The slits formed in the slit plate 15a are formed at regular intervals except for the reference position where the measurement light is irradiated toward the center of the non-scanning angle region, and the slit interval is formed at a narrower interval than the other intervals at the reference position. Has been. Accordingly, the rotation angle position of the deflection optical system 4 can be grasped from the reference position based on the pulse width of the pulse output from the scanning angle detector 15 as the deflection optical system 4 rotates.

  A prism 16 as a distance correction reference optical system is provided at the center of the non-scanning angle region, and a reference distance for correction is obtained based on reflected light detected by the light receiving unit 5 through the prism 16. It is done.

  A control board 17 including a signal processing circuit 20 that drives the apparatus and calculates the distance to the object T is housed in the bottom of the casing 2.

  As shown in FIG. 2, the signal processing circuit 20 includes a driving circuit 3b for driving the light emitting element 3a, an amplifying circuit 5b for amplifying a reflected signal obtained by photoelectrically converting the reflected light by the light receiving element 5a, a motor control circuit 21, A / D conversion unit 22, signal processing unit 23, and system control unit 24 are provided. The signal processing unit 23 and the system control unit 24 constitute a signal processing device according to the present invention.

  The system control unit 24 is provided with a microcomputer that operates based on a predetermined control program, and the microcomputer controls the signal processing unit 23, the motor control circuit 21, and the like.

  The system control unit 24 detects the scanning angle, that is, the irradiation direction of the measurement light, based on the encoder pulse input from the scanning angle detection unit 15, and the measurement light is periodically emitted by the deflection optical system 4 at a predetermined constant speed. The motor control circuit 21 is controlled so that the measurement target space is scanned.

  Then, a distance input from the signal processing unit 23, measurement information such as a scanning angle detected via the scanning angle detection unit 15, or an obstacle detection signal indicating that an obstacle exists in the monitoring target area, Output to an external device connected via the interface.

  The signal processing device is housed inside the casing 2 and is configured integrally with the scanning distance measuring device 1, and is installed outside the casing 2 and configured separately from the scanning distance measuring device 1. It may be. In the latter case, the signal processing device is connected to the control board 17 inside the casing 2 on which the A / D conversion unit 22 and the like are mounted via a signal line or via a wireless communication unit.

  In synchronization with the encoder pulse input from the scanning angle detector 15, the infrared semiconductor laser 3a is pulse-driven by the drive pulse signal S1 output from the signal processor 23 to the drive circuit 3b, and the measurement target space is pulsed. Measurement light S2 is irradiated.

  The measurement light S2 is irradiated onto the object T, the reflected light S3 from the object T is photoelectrically converted by the avalanche photodiode 5a, and the reflected signal S4 amplified by the amplifier circuit 5b is converted into the A / D converter 22. Is input.

The digital reflection signal A / D converted by the A / D conversion unit 22 is input to the signal processing unit 23, and the signal processing unit 23 obtains the time difference Δt between the drive pulse signal S1 and the reflection signal. Thus, a temporary distance D1 to the measurement object T is calculated.
D1 = Δt · C / 2 (where C is the speed of light)

  Here, the time difference Δt refers to the delay time of the reflected light with respect to the measurement light. In the above example, the irradiation timing of the measurement light is substituted with the rising timing of the drive pulse signal S1, but a photoelectric sensor that detects the measurement light is used. It may be used to detect the rising timing of the measurement light itself.

On the other hand, when the encoder pulse input from the scanning angle detector 15 indicates the reference position, the measurement light is applied to the prism 16, and the time difference Δt ′ based on the reflected light S3 from the prism 16 detected by the avalanche photodiode 5a. Is calculated based on the following equation.
D2 = Δt ′ · C / 2 (where C is the speed of light)

  A distance D to the object to be measured is calculated by D1-D2. The reference distance D2 absorbs variations in characteristics of the infrared semiconductor laser 3a, the drive circuit 3b, the avalanche photodiode 5a, and the like incorporated in the scanning distance measuring device 1, and variations in measurement distance due to differences in optical systems. A correction value for calculating an accurate distance to the object to be measured.

  By the way, when a comparator for comparing with a predetermined threshold voltage is provided in order to detect the rising timing of the reflected signal S4, the rising waveform slope varies depending on the signal intensity even for the reflected signal S4 generated at the same timing. In addition, the output timing from the comparator may fluctuate and the rising timing of the reflected signal S4 may not be detected accurately.

  Therefore, the signal processing unit 23 first differentiates the reflected signal S4, calculates the centroid position of the positive region of the primary differential reflected signal with reference to the rising timing of the primary differentiated reflected signal, and reflects the time corresponding to the centroid position. The detection time of the light S3 is obtained.

The first to third aspects of the signal processing apparatus according to the present invention will be described below.
First, the first aspect will be described in detail.

  As shown in FIG. 3, the signal processing unit 23 is composed of an integrated circuit such as an ASIC having a gate array for signal processing, a digital signal processor, and a plurality of registers serving as a data storage unit for various operations. Has been.

  By these integrated circuits, the distance calculation unit 230 that calculates the distance D to the object to be measured, and the monitoring object detection that detects the monitoring object that becomes an obstacle based on the distance information calculated by the distance calculation unit 230 and the like. Each functional block of the unit 231 and a pulse signal generation unit 232 that generates a clock signal for driving the drive circuit 3b, the distance calculation unit 230, and the like is configured.

  The distance calculation unit 230 includes a distance measurement calculation unit 23a that calculates the above-described distances D1 and D2, a correction data storage unit 23c that stores the calculated correction distance D2, and a correction processing unit 23b that performs the above-described distance correction calculation. It is a functional block provided.

  The distance calculation unit 230 calculates a distance from the scanning distance measuring device 1 to an object existing in the monitoring target area for each predetermined scanning angle based on a predetermined correlation between the measurement light and the reflected light. This process is repeated at the scanning period of the measurement light. The predetermined correlation means a correlation between the delay time of the reflected light with respect to the measurement light and the distance in the TOF method, and a correlation between the phase difference of the reflected light with respect to the measurement light and the distance in the AM method.

  The monitoring object detection unit 231 includes a monitoring object area setting unit 23g, an area determination unit 23h, a group generation processing unit 23i, a monitoring object determination unit 23j, a scanning angle / distance storage unit 23d, and a group storage unit 23e. And a functional block including a minimum detection width setting unit 23f.

  The monitoring object detection unit 231 determines whether the reflected light from the object detected by the scanning distance measuring device 1 is noise light reflected from minute dust or insects other than the monitoring object, or within the monitoring object area. It is provided in order to determine whether or not the signal light is reflected from the entering or invading monitoring object and appropriately detect the monitoring object.

  The monitoring target area setting unit 23g includes a memory in which area data that defines the boundary of the monitoring target area to be monitored by the scanning distance measuring device 1 is stored. The area data is input from an external device such as a computer connected to the system control unit 24 and stored in advance in the memory via the system control unit 24.

  The scanning angle / distance storage unit 23d stores the scanning angle and distance of the object calculated by the distance calculation unit 230 for each scanning period. Whether the area determination unit 23h is a distance in which the distance of the object for each scanning period stored in the scanning angle / distance storage unit 23d is located inside the monitoring target area stored in the memory of the monitoring target area setting unit 23g. Only when it is located inside the monitoring target area, the distance and the scanning angle are handed over to the group generation processing unit 23i.

  The group generation processing unit 23i generates a group in which distance data existing in a plurality of scanning angle directions continuous along the scanning direction of the measurement light is combined, and assigns an identifier of the group to each distance data. The representative distance of the group is set, and those data are stored in the group storage unit 23e.

  The minimum detection width storage unit 23f stores the number of distance data indicating an object detection minimum width set in advance according to the distance from the scanning distance measuring device 1. The minimum object detection width is the size of the object along the scanning direction of the measurement light for determining whether the object is a monitoring object or noise, and the number of distance data indicating this is the scanning distance measurement The distance is set to be smaller as the distance from the device 1 is longer. The number of distance data indicating the minimum object detection width is input and stored in advance from an external device connected to the system control unit 24.

  The representative distance of a group is a value for specifying one of a plurality of minimum object detection widths stored in the minimum detection width storage unit 23f, and is either an average value or a median value of distance data included in the group. Alternatively, any value from the value to the maximum value of the distance data is set.

  The value indicating the minimum object detection width stored in the minimum detection width storage unit 23f may be angle data defined by the maximum scanning angle. Also in this case, the distance is set to be smaller as the distance from the scanning distance measuring device 1 is longer. In the following description, the case where the object detection minimum width is the number of distance data will be described. However, the same processing can be applied to angle data.

  When the group generation processing unit 23i performs the grouping process for each scanning cycle, the monitoring object determination unit 23j is activated. The monitoring object determining unit 23j reads the number indicating the minimum object detection width from the minimum detection width storage unit 23f according to the table distance of each group, and the number of distance data that is the object detection width of each group is the object detection. When the number of objects indicating the minimum width is equal to or greater than the number indicating the object detection width, it is determined that there is an object to be monitored, and the number of distance data that is the object detection width of each group is less than the number indicating the object detection minimum width. Is determined not to exist.

  When the monitoring object detection unit 231 detects the presence of the monitoring object, a signal to that effect is output to the system control unit 24, and the monitoring object detection signal in the on state is output from the system control unit 24 to the external device. Is output.

  When the monitoring object detection unit 231 detects that the monitoring object does not exist, a signal to that effect is output to the system control unit 24, and the monitoring object detection signal in the off state is output from the system control unit 24 to the external device. Is output. That is, the system control unit 24 serves as a signal output unit that outputs a monitoring object detection signal to the outside.

  When a monitoring object detection signal is input from the system control unit 24, the external device executes a predetermined process such as a stop control for safety of the device installed in the monitoring target area. .

  FIG. 4 shows a flowchart of monitoring object detection processing executed by the signal processing devices 23 and 24 described above. A distance calculation process for the object is executed by the distance calculation unit 230, and the value is stored in the scanning angle / distance storage unit 23d (S1). The area determination processing is executed by the area determination processing section 23h (S3), and the scanning angle / distance data in the monitoring target area is delivered to the group generation processing section 23i.

  The group generation processing unit 23i executes group generation processing (S3), the monitoring target object determination processing unit 23j executes monitoring target object determination processing (S4), and the system control unit 24 executes obstacle detection signal output processing. (S5).

  FIG. 5 shows a scanning cycle of 30 msec. From the scanning distance measuring device 1 toward the fan-shaped monitoring target area whose maximum distance is set to a value of 10 m. In this case, the measurement light is repeatedly scanned and the reflected light from the object with respect to the measurement light is detected at every scanning angle θ (= 0.25 °), thereby detecting a monitoring target as large as a human arm. An illustration is shown. In the figure, a hatched large ellipse is a monitoring object T, and a small black circle is a minute object that becomes noise.

  In this example, the width of the scanning angle θ of 0.25 ° is about 4.36 cm at a position 10 m away from the scanning distance measuring device 1. That is, when an object T is detected at a position of 10 m continuously at adjacent scanning angles, it can be determined that there is at least an object of a human arm.

  The upper part of FIG. 5 shows a state in which the measurement light is rotationally scanned counterclockwise from the scanning distance measuring device 1. Reference numerals 11, 21, 31,..., 101, and 111 indicate the scanning angle direction (also referred to as “step”).

  In the lower part of FIG. 5, a table of the scanning angle direction and the calculated distance is shown. In this example, the distance to the minute object (indicated by black circles in the figure) is calculated in the scanning angle directions 2l and 3l, the distance to the monitoring object T is calculated in the scanning angle directions 5l, 6l, 8l, and 9l, and the scanning angle The distance to another minute object (indicated by a black circle in the figure) is calculated in the direction 7l.

  In addition, when the distance calculated by the distance calculation unit 230 is not a monitoring target or when the distance is not calculated, the frame of the calculated distance is hatched. The numerical value in the frame is the maximum distance of the monitoring target area.

  In this example, the distance data is divided into two groups, group G1 and group G2, by the group generation processing unit 23i, and each distance data to which the identifier of the group G1 or group G2 is assigned and the representative distance are stored in the group storage unit 23e. Remembered. The representative distance is set to the maximum value of the distance data included in the group, the representative distance of the group G1 is set to 2.5 m, and the representative distance of the group G2 is set to 3.6 m.

  The minimum detection width storage unit 23f stores a minimum object detection width corresponding to the distance from the scanning distance measuring device 1. In this example, the value of the minimum object detection width is set to 3 when the distance from the scanning distance measuring device 1 is less than 3.0 m, and is set to 2 when the distance from the scanning distance measuring device 1 is 3.0 m or more. Has been.

  Since the number 2 of the distance data of the group G1 is smaller than the minimum object detection width 3 corresponding to the representative distance 2.5 m of the group G1, the monitoring object determining unit 23j does not detect the group G1 as a monitoring object. Judged as noise.

  Furthermore, since the number 5 of the distance data of the group G2 is larger than the minimum object detection width 2 corresponding to the representative distance 3.6 m of the group G2, the monitoring target determining unit 23j determines that the group G2 is the monitoring target. It is determined that

  As described above, in the signal processing devices 23 and 24, the distance data continuously calculated at the scanning angles continuous along the scanning direction is grouped regardless of the value, and therefore, another object behind is continuous. An inconvenient situation in which the sex is cut off by a small object in the vicinity does not occur.

  Note that the representative distance of the group for determining whether or not it is a monitoring object is set to any value from the average value or median value of a plurality of distance data in the group to the maximum value of the distance data. For example, it is possible to make a determination that attaches importance to an object located farther than an object located nearer to the scanning distance measuring device.

The second aspect of the signal processing apparatus of the present invention will be described below.
FIG. 6 shows a block diagram of the signal processing unit 23 of the second aspect. Compared with the signal processing unit 23 shown in FIG. 3, the group generation processing unit 23i has a different group generation reference, and includes a group integration processing unit 23k in addition to the group generation processing unit 23i.

  In the first aspect, in the group generation processing unit 23i, the distance data calculated by the distance calculation unit 230 is a value indicating the inside of the monitoring target area, and the distance data is continuously along the scanning direction of the measurement light. In the second aspect, the group is generated based on the value of each distance data. Configured to generate.

  This will be specifically described below. The group generation processing unit 23i has a plurality of scanning angle directions in which the distance data calculated by the distance calculating unit 230 is a value indicating the inside of the monitoring target area, and the distance data is continuous along the scanning direction of the measurement light. Are formed so as to generate a group of a plurality of distance data in which the difference between the distance data in the adjacent scanning angle directions is equal to or less than the first threshold.

  Then, the group generation processing unit 23i is configured to set any value from the average value or median value of the distance data included in the group to the maximum value of the distance data as the representative distance of the group. .

  The first threshold value is a threshold value that allows the object to be estimated as the same object, and is a value that is set in advance based on the uneven shape of the surface of the monitoring object. In this example, it is set to 0.2 m.

  As shown in FIG. 7, the group generation processing unit 23i divides the distance data into four groups of groups G1, G2, G3, and G4, and stores each distance data in which an identifier is assigned to each group and the representative distance as a group storage. Stored in the unit 23e. The representative distance is set to the maximum value of the distance data included in the group.

  Also in this example, the value of the minimum object detection width stored in the minimum detection width storage unit 23f is set to 3 when the distance from the scanning distance measuring device 1 is less than 3.0 m, and the distance from the scanning distance measuring device 1 is set. The distance is set to 2 at 3.0 m or more.

  In such a case, the monitoring object determination unit 23j cannot determine that any of the groups G1, G2, G3, and G4 has a monitoring object, and therefore outputs the determination result to the system control unit 24. Without starting up, the group integration processing unit 23k is activated.

  The group integration processing unit 23k generates one new group G (2 + 3) in which the groups G2 and G3 are grouped out of the three adjacent groups G2, G3, and G4, and is included in the new group G (2 + 3) The maximum value of the distance data to be set is set as the representative distance of the new group, and the determination by the monitoring object determination unit 23j is activated again.

  Since the number 3 of the distance data of the group G (2 + 3) is larger than the object detection minimum width 2 corresponding to the representative distance 3.6 m of the group G (2 + 3), the monitoring target determination unit 23j It is determined that (2 + 3) is the monitoring target.

  In the signal processing devices 23 and 24 according to the second aspect, some other object exists behind a small object as a noise source located in the vicinity when viewed from the scanning distance measuring device 1, and the other object behind the Even when the continuity is interrupted by a small object in the vicinity, another object behind can be determined as the monitoring target.

  When three or more groups are adjacent to each other in the scanning direction, the group integration processing unit 23k can appropriately adopt any one of the following modes to integrate the groups.

  Among the plurality of groups generated by the group generation processing unit 23i, when groups adjacent to a certain group exist on both sides along the scanning direction, the sum of the number of distance data constituting the two adjacent groups is the maximum. By integrating the groups to generate one new group, the presence or absence of the monitoring target can be properly determined on the safety side.

  That is, the group integration processing unit 23k preferably generates one new group by combining two adjacent groups with the maximum number of distance data.

  In the case shown in FIG. 8A, when the group G2 and the group G3 are integrated, the sum of the number of distance data becomes 4, which is larger than the sum 3 of the number of distance data when the group G3 and the group G4 are integrated. Then, the group G2 and the group G3 are integrated into a new group G (2 + 3). In addition, as shown in FIG. 7, even if it integrates with any adjacent group, if the sum of the number of distance data is equal, it should just integrate with any one group.

  In addition, when a plurality of groups are adjacent along the scanning direction, the group integration processing unit 23k combines a group with a short representative distance and a group with a long representative distance adjacent to the group with a short representative distance. It is preferable to generate a group.

  If the groups are integrated based on the group having a short representative distance as described above, the group located in the vicinity as viewed from the scanning distance measuring device 1 and the far-side group adjacent to the group are integrated into one new group. Therefore, the determination of the minimum object detection width for the far side group is appropriately performed.

  Further, the group integration processing unit 23k, when a group with a long representative distance is adjacent to both sides of a group with a short representative distance, determines the difference in the integrated reference distance obtained from the distance data of the group with a long representative distance located on both sides. When the threshold value is less than or equal to the second threshold, it is preferable to create a new group by combining the group with the shorter representative distance and the group with the longer representative distance on both sides.

  The integrated reference distance is a distance for determining the probability that two groups having long representative distances located on both sides are distances to the same object. As the integrated reference distance, any one of the distance data in the scanning angle direction closest to the group having a short representative distance, the representative distance, the average value of the distance data in the group, the median value, and the like can be adopted.

  The second threshold value is also a threshold value that can be estimated as the same object, and is a value that is set in advance based on the uneven shape of the surface of the monitoring object. The second threshold value is preferably set to a value larger than the first threshold value described above.

  When the difference between the integration reference distances of the groups with long representative distances on both sides is equal to or less than the second threshold, it is determined that the distance data belonging to these groups is the distance data for the same object, and these groups are integrated. Thus, the determination of the minimum object detection width for the far-side group is appropriately performed.

  FIG. 8B shows an example in which distance data in the scanning angle direction closest to the group having a short representative distance is adopted as the integrated reference distance. The integrated reference distance of group G2 is 3.3 m, the integrated reference distance of group G4 is 3.2 m, and the difference is 0.1 m.

  In this example, the second threshold is set to 0.3 m. Therefore, the groups G2, G3, and G4 are integrated into a new group G (2 + 3 + 4).

  FIG. 8C shows still another example. In this example, the groups G2, G3, G4, and G5 are adjacent along the scanning direction. The integrated reference distance of the group G2 is 2.5 m, the integrated reference distance of the group G3 is 3.3 m, and the integrated reference distance of the group G5 is 3.2 m. Since the difference between the integrated reference distances of the groups G3 and G5 is 0.1 m and the difference between the integrated reference distances of the groups G2 and G3 is 0.8 m, the groups G3 and G5 whose difference is equal to or less than the second threshold value 0.3 m. Are combined to generate a new group G (3 + 4 + 5).

The third aspect will be described below.
The third aspect is an aspect applied to a scanning distance measuring device that can calculate a plurality of distances in the same scanning angle direction by the distance calculation unit 230, such as the TOF method. The functional block configuration is based on FIG.

  The group generation processing unit 23i has a plurality of scanning angle directions in which the distance data calculated by the distance calculating unit 230 is a value indicating the inside of the monitoring target area, and the distance data is continuous along the scanning direction of the measurement light. Are formed so as to generate a group of a plurality of distance data in which the difference between the distance data in the adjacent scanning angle directions is equal to or less than the first threshold.

  Then, the group generation processing unit 23i sets any value from the average value or median value of the distance data included in the group to the maximum value of the distance data as the representative distance of the group, and the monitoring object determination unit 23j is activated.

  As shown in FIG. 9, when the light beam Lw of the measurement light output from the light projecting unit 3 is wider than the minute object O1, the measurement light is also irradiated to the object O2 farther than the minute object O1. Therefore, the reflected light from both the near and near objects O 1 and O 2 is detected by the light receiving unit 5.

  FIG. 8D shows a case where two distances are calculated in the same scanning angle direction 7 l by the distance calculation unit 230 corresponding to FIG. 9. That is, the distance calculation unit 230 calculates the distance 1.2 m corresponding to the object O1 in the scanning angle direction 71 and the distance 3.2 m corresponding to the object O2.

  For example, when the first threshold is set to 0.2 m, the group generation processing unit 23i generates three groups G1, G2, and G3. The group G2 is a group of distance data in which the difference between adjacent distance data in the scanning angle directions 5l to 9l is equal to or less than the first threshold.

  If a group is generated in this way, even if there is some other object O2 behind a small object O1 as a noise source located in the vicinity when viewed from the scanning distance measuring apparatus 1, there is another group behind the Since the continuity of the object O2 is not interrupted by a small object in the vicinity, another object O2 behind is generated as one group by the group generation processing unit 23i, and the monitoring object can be properly detected. become able to.

  When part of the reflected light from both near and near objects is superimposed, the reflected signal is separated before and after the second rise timing of the second derivative signal of the reflected signal, and the rise timing of each reflected signal is determined. The distance may be calculated as the detection timing of the reflected light.

  In any aspect described above, it is preferable to set the maximum value of the distance data included in the group as the representative distance of the group. If the maximum value of the distance data included in the group is set as the representative distance, irradiation of the measuring light to the object located on the far side of the scanning distance measuring device at a certain scanning angle is blocked by the minute object on the near side. In this case, it is possible to determine an appropriate object detection minimum width corresponding to the distance of an object located far away.

  Further, it is preferable that the minimum object detection width is set to become smaller as the representative distance becomes longer. Even for objects of the same size, the number of scanning angles detected continuously in the vicinity of the scanning distance measuring device is large, or the maximum scanning angle is large, and it is detected continuously in the distance of the scanning distance measuring device. The number of scanning angles to be reduced is small, or the maximum scanning angle is small. Therefore, if the minimum object detection width is reduced as the representative distance of the group becomes longer, it is determined whether or not an object existing at any distance from the perspective of the scanning distance measuring device is properly monitored. Can be judged.

  In the above-described embodiment, the scanning distance measuring device 1 has been described with respect to the configuration in which the measurement light is scanned one-dimensionally along the plane orthogonal to the fixed axis P by the deflection optical system 4. The present invention can also be applied to a scanning distance measuring device in which measurement light is scanned two-dimensionally and the distance to an object can be measured in three dimensions.

  For example, by incorporating a mechanism for swinging the axis P into the scanning distance measuring device 1 described above, a deflection optical system capable of two-dimensionally scanning the measurement light can be realized.

  It is also possible to simultaneously measure multiple scanning angles, such as a distance measuring device that scans the measurement light two-dimensionally on the XY plane, a distance measuring device that randomly scans two-dimensionally, and a trigonometric scan that uses two CCDs. The technical idea of the present invention can also be applied to a distance measuring device.

  Even when the measurement light is scanned two-dimensionally by adopting the first aspect described above, the distance data calculated by the distance calculation unit and indicating the inside of the monitoring target region is irrespective of the scanning direction of the measurement light. In addition, when a plurality of adjacent scanning angle directions exist, a group in which the plurality of distance data are collected may be generated.

  Monitoring is performed when the number of distance data included in the group or the object detection width defined by the maximum scanning angle is equal to or larger than the number indicating the minimum object detection width set in advance according to the representative distance or the scanning angle. What is necessary is just to determine with a target object existing. In this case, the minimum object detection width can be set as the number of distance data occupying a certain two-dimensional area.

  The above-described embodiments are examples of the signal processing device, the signal processing method, and the scanning distance measuring device of the scanning distance measuring device according to the present invention. The specific structure of the scanning distance measuring device and the specifics of the signal processing device. Needless to say, the specific procedure of software for realizing a simple circuit configuration and signal processing method can be changed and designed as appropriate within the scope of the effects of the present invention, and the technical scope of the present invention is limited to the above examples. Is not to be done.

1: Scanning distance measuring device 3: Projecting unit 5: Light receiving unit 4: Scanning unit 23: Signal processing unit (signal processing device)
23a: Distance measurement calculation unit 23b: Correction processing unit 23c: Correction data storage unit 23d: Scanning angle / distance storage unit 23e: Group storage unit 23f: Minimum detection width setting unit 23g: Monitoring target region setting unit 23h: Region determination processing unit 23i: Group generation processing unit 23j: Monitoring object determination unit 23k: Group integration processing unit 230: Distance calculation unit (signal processing device)
231: Monitoring object detection (signal processing device)

Claims (7)

A signal processing device of a scanning distance measuring device that scans measurement light toward a monitoring target region and detects reflected light from an object with respect to the measurement light at every predetermined scanning angle,
A distance calculation unit that calculates a distance from the scanning distance measuring device to the object based on a predetermined correlation between the measurement light and the reflected light for each predetermined scanning angle;
When distance data calculated by the distance calculation unit and indicating the monitoring target area exists in a plurality of adjacent scanning angle directions, a group in which the plurality of distance data is collected is included in the group. A group generation processing unit that sets any value from the average value or median value of the distance data to the maximum value of the distance data as the representative distance of the group;
The number of distance data included in the group generated by the group generation processing unit or the object detection width defined by the maximum scanning angle is equal to or greater than the number indicating the minimum object detection width preset according to the representative distance or scanning. A monitoring object determination unit that determines that a monitoring object exists when the angle is equal to or greater than an angle;
As a result of the determination by the monitoring object determination unit, when it is determined that the monitoring object exists, a signal output unit that outputs a monitoring object detection signal indicating that,
A signal processing device for a scanning distance measuring device. A signal processing device of a scanning distance measuring device that scans measurement light toward a monitoring target region and detects reflected light from an object with respect to the measurement light at every predetermined scanning angle,
A distance calculation unit that calculates a distance from the scanning distance measuring device to the object based on a predetermined correlation between the measurement light and the reflected light for each predetermined scanning angle;
When distance data calculated by the distance calculation unit and indicating the inside of the monitoring target area exists in a plurality of adjacent scanning angle directions, the difference between the distance data in the adjacent scanning angle directions is equal to or less than a first threshold value. Generate a group in which a plurality of distance data is collected, and generate a group in which any value from the average value or median value of the distance data included in the group to the maximum value of the distance data is set as the representative distance of the group A processing unit;
The number of distance data included in the group generated by the group generation processing unit or the object detection width defined by the maximum scanning angle is equal to or greater than the number indicating the minimum object detection width preset according to the representative distance or scanning. A monitoring object determination unit that determines that a monitoring object exists when the angle is equal to or greater than an angle;
As a result of the determination by the monitoring object determination unit for a plurality of adjacent groups, when it is determined that there is no monitoring object, a new group is created by combining the two adjacent groups, and the new A group integration processing unit that sets any value from the average value or median value of the distance data included in the group to the maximum value of the distance data as the representative distance of the new group;
As a result of determination by the monitoring object determination unit for the group generated by the group generation processing unit or the group integration processing unit, when it is determined that a monitoring object exists, a monitoring object detection signal indicating that is provided. A signal output section to output;
With
The group integration processing unit is a signal processing device of a scanning distance measuring device that generates two new adjacent groups by maximizing the number of distance data. Wherein the representative distance, the signal processing apparatus of a scanning type distance measuring apparatus according to claim 1 or 2, wherein the maximum value of the distance data contained in the group is set. Value indicating the object detection minimum width, the signal processing apparatus of a scanning type distance measuring apparatus according to any one of claims 1 to 3 is set to be smaller as the representative distance is longer. Scanning type distance measuring apparatus signal processing apparatus of a scanning type distance measuring device is incorporated according to any of claims 1 4. A scanning distance measuring device signal processing method that scans measurement light toward a monitoring target area and detects reflected light from an object with respect to the measurement light at each predetermined scanning angle,
A distance calculating step for calculating a distance from the scanning distance measuring device to the object based on a predetermined correlation between the measurement light and the reflected light for each predetermined scanning angle;
When distance data calculated in the distance calculation step and indicating the inside of the monitoring target area exists in a plurality of adjacent scanning angle directions, a group in which the plurality of distance data are collected is generated and included in the group A group generation processing step of setting any value from the average value or median value of the distance data to the maximum value of the distance data to the representative distance of the group;
The number of distance data included in the group generated in the group generation processing step or the object detection width defined by the maximum scanning angle is equal to or larger than the number indicating the minimum object detection width preset according to the representative distance or scanning. A monitoring object determination step for determining that the monitoring object exists when the angle is equal to or greater than the angle;
As a result of the determination of the monitoring object determination step, when it is determined that the monitoring object exists, a signal output step of outputting a monitoring object detection signal indicating that,
A signal processing method for a scanning distance measuring apparatus. A scanning distance measuring device signal processing method that scans measurement light toward a monitoring target area and detects reflected light from an object with respect to the measurement light at each predetermined scanning angle,
A distance calculating step for calculating a distance from the scanning distance measuring device to the object based on a predetermined correlation between the measurement light and the reflected light for each predetermined scanning angle;
When the distance data calculated in the distance calculation step and indicating the inside of the monitoring target area exists in a plurality of adjacent scanning angle directions, the difference between the distance data in the adjacent scanning angle directions is equal to or less than the first threshold value. Generate a group in which a plurality of distance data is collected, and generate a group in which any value from the average value or median value of the distance data included in the group to the maximum value of the distance data is set as the representative distance of the group Processing steps;
The number of distance data included in the group generated in the group generation processing step or the object detection width defined by the maximum scanning angle is equal to or larger than the number indicating the minimum object detection width preset according to the representative distance or scanning. A monitoring object determination step for determining that the monitoring object exists when the angle is equal to or greater than the angle;
As a result of the determination in the monitoring object determination step for a plurality of adjacent groups, when it is determined that there is no monitoring object, a new group is created by combining the two adjacent groups, and the new A group integration processing step of setting any value from the average value or median value of the distance data included in the group to the maximum value of the distance data as the representative distance of the new group;
When it is determined that the monitoring target exists as a result of the monitoring target determination step for the group generated in the group generation processing step or the group integration processing step, a monitoring target detection signal indicating that is present A signal output step to output;
With
The group integration processing step is a signal processing method for a scanning distance measuring apparatus that generates two new adjacent groups by maximizing the number of distance data.

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