WO2024090116A1

WO2024090116A1 - Data processing device, optical sensor, data processing method, and data processing program

Info

Publication number: WO2024090116A1
Application number: PCT/JP2023/035322
Authority: WO
Inventors: 浩上杉
Original assignee: 株式会社デンソー
Priority date: 2022-10-28
Filing date: 2023-09-28
Publication date: 2024-05-02
Also published as: JP2024064554A

Abstract

A processor of this data processing device is configured to acquire detection data. The detection data includes distance measurement data including physical information relating to a light reception peak in reflected light received in response to emitted light emitted at a distance measurement luminous intensity, which is the luminous intensity in a distance measurement frame. The detection data includes comparative data including physical information relating to a light reception peak in reflected light with respect to emitted light emitted at a comparative luminous intensity different from the distance measurement luminous intensity, in a comparison frame different from the distance measurement frame. The processor is configured to exclude, from the distance measurement data, a light reception peak for which a normal condition is not satisfied, the normal condition being that between the distance measurement data and the comparative data, the difference in intensity ratio between the luminous intensity and the light reception intensity at the light reception peak is within an allowable intensity range, and the difference in light reception timing at the light reception peak is within an allowable time range.

Description

Data processing device, optical sensor, data processing method, and data processing program

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Patent Application No. 2022-173227 filed in Japan on October 28, 2022, and the contents of the original application are incorporated by reference in their entirety.

This disclosure relates to data processing technology that processes detection data generated by an optical sensor.

Patent document 1 discloses a LiDAR (Light Detection and Ranging/Laser Imaging Detection and Ranging) device. This device changes the illumination intensity of an emitted pulsed beam of light based on the intensity of the measured return pulse. Specifically, the device sets the illumination intensity so that the intensity of the return pulse falls within the linear range of an AD converter.

Specific Publication No. 2021-510417

Incidentally, optical sensors such as the LiDAR device of Patent Document 1 may receive light emitted from a light source such as another optical sensor as crosstalk light. In this case, there is a risk that the crosstalk light may be mistaken for light reflected by the target from the light emitted by the optical sensor itself.

An object of the present disclosure is to provide a data processing device capable of suppressing false detections. Another object of the present disclosure is to provide an optical sensor capable of suppressing false detections. Yet another object of the present disclosure is to provide a data processing method capable of suppressing false detections. Yet another object of the present disclosure is to provide a data processing program capable of suppressing false detections.

The technical means of the present disclosure for solving the problems will be explained below. Note that the reference characters in parentheses in the claims indicate the corresponding relationship with the specific means described in the embodiments described in detail later, and do not limit the technical scope of the present disclosure.

A first aspect of the present disclosure is a data processing device having a processor, which processes detection data generated by an optical sensor that detects a target by receiving reflected light that is reflected by a target from an irradiated light on a detection area,
The processor
acquiring detection data including distance measurement data including physical information regarding a light reception peak in a reflected light received in response to irradiation light irradiated at a distance measurement light emission intensity, which is an emission intensity in a distance measurement frame; and comparison data including physical information regarding a light reception peak in a reflected light in response to irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
Excluding from the distance measurement data, a light reception peak that does not satisfy a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak is within an allowable intensity range and a difference in a light reception timing at the light reception peak is within an allowable time range between the distance measurement data and the comparison data;
The apparatus is configured to execute the following steps:

A second aspect of the present disclosure is an optical sensor that detects a target by receiving reflected light that is reflected by the target and is irradiated onto a detection area,
A light-emitting unit that emits irradiation light;
A light receiving unit that receives reflected light;
A control unit for acquiring detection data from the light receiving unit;
Equipped with
The control unit
an acquisition unit that acquires detection data including distance measurement data including physical information on a light reception peak in a reflected light received in response to irradiation light irradiated at a distance measurement light emission intensity, which is an emission intensity in a distance measurement frame, and comparison data including physical information on a light reception peak in a reflected light received in response to irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
an exclusion unit that excludes from the distance measurement data a light reception peak that does not satisfy a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak is within a permissible intensity range and a difference in light reception timing at the light reception peak is within a permissible time range, between the distance measurement data and the comparison data;
has.

A third aspect of the present disclosure is a data processing method executed by a processor to process detection data generated by an optical sensor that detects a target by receiving reflected light that is reflected by a target from an irradiated light onto a detection area, the data processing method comprising:
acquiring detection data including distance measurement data including physical information regarding a light reception peak in a reflected light received in response to irradiation light irradiated at a distance measurement light emission intensity, which is an emission intensity in a distance measurement frame; and comparison data including physical information regarding a light reception peak in a reflected light in response to irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
Excluding from the distance measurement data, a light reception peak that does not satisfy a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak is within an allowable intensity range and a difference in a light reception timing at the light reception peak is within an allowable time range between the distance measurement data and the comparison data;
including.

A fourth aspect of the present disclosure is a data processing program stored in a storage medium for processing detection data generated by an optical sensor that detects a target by receiving light reflected by the target from an irradiated light on a detection area, the data processing program including instructions to be executed by a processor,
The command is,
acquiring detection data including distance measurement data including physical information regarding a light reception peak in a reflected light received in response to irradiation light irradiated at a distance measurement light emission intensity, which is an emission intensity in a distance measurement frame; and comparison data including physical information regarding a light reception peak in a reflected light in response to irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
Excluding from the distance measurement data, a light reception peak that does not satisfy a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak is within an allowable intensity range and a difference in a light reception timing at the light reception peak is within an allowable time range between the distance measurement data and the comparison data;
including.

According to the first to fourth aspects, light reception peaks that do not meet the normal conditions in detection data with different light emission intensities are excluded from the distance measurement data. Since the light reception intensity of crosstalk light from other light sources does not depend on the light emission intensity of the optical sensor and the light reception timing can change significantly, light reception peaks that do not meet the normal conditions can be attributed to crosstalk light. This makes it possible to suppress erroneous detections.

FIG. 1 is a block diagram showing an overall configuration of a first embodiment. 1 is a schematic diagram showing a driving environment of an autonomous guided vehicle to which an optical sensor according to a first embodiment is applied; FIG. 2 is a block diagram showing a functional configuration of a control unit according to the first embodiment. 4 is a flowchart showing a data processing flow according to the first embodiment. FIG. 2 is a diagram conceptually showing generation of a distance image from each frame. 13 is a diagram conceptually showing light receiving and emitting processing of a distance measurement frame in one scanning line. FIG. 13A and 13B are diagrams conceptually illustrating light receiving and emitting processes in a comparison frame. 11 is a graph showing an example of background light data when crosstalk light is incident. 11 is a table showing an example of a pattern of comparative luminescence intensities. 13 is a table showing specific numerical examples for each pattern.

Below, several embodiments of the present disclosure will be described with reference to the drawings. Note that in each embodiment, corresponding components are given the same reference numerals, and duplicated descriptions may be omitted. Furthermore, when only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the other portions of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

First Embodiment
The optical sensor 1 of the first embodiment shown in Fig. 1 is mounted on an autonomous transport vehicle 2 shown in Fig. 2. From a viewpoint centered on the autonomous transport vehicle 2, the autonomous transport vehicle 2 can also be said to be an ego-vehicle. The autonomous transport vehicle 2 is an autonomous travel robot capable of autonomous travel in any direction, including forward, backward, left and right. The autonomous transport vehicle 2 is a vehicle that autonomously travels in a facility such as a warehouse to transport an object. The autonomous transport vehicle 2 is, for example, a forklift capable of autonomous travel. The optical sensor 1 detects a target T, such as an object to be transported, within a travel area.

The optical sensor 1 is a so-called LiDAR that detects the target T by receiving the reflected light Br of the irradiated light Bi reflected by the target T. The optical sensor 1 can detect the distance from the optical sensor 1 to the target T according to the time of flight (Time Of Flight) from when the irradiated light Bi is irradiated to when it is received as the reflected light Br. The optical sensor 1 is composed of a light emitting unit 10, a scanning unit 20, a light receiving unit 30, and a control unit 100.

The light-emitting unit 10 includes a plurality of semiconductor elements, such as laser diodes, that emit directional laser light. The light-emitting unit 10 applies a current to the semiconductor elements in response to a control signal from the control unit 100, thereby irradiating light toward the outside of the autonomous transport vehicle 2 in the form of an intermittent pulse beam. In the light-emitting unit 10, each semiconductor element can irradiate irradiation light Bi corresponding to each pixel in each scanning line L, for example, in response to the reflection angle of the scanning unit 20 described below. The light-emitting unit 10 can irradiate laser light in an oscillating LD (Laser Diode) mode by applying a current in a range larger than the boundary current value to the semiconductor elements. The light-emitting unit 10 can irradiate LED light in a non-oscillating LED (Light Emitting Diode) mode by applying a current in a range smaller than the boundary current value to the semiconductor elements. In this embodiment, the LED mode is not executed.

The scanning unit 20 includes a reflector that reflects the beam emitted from the light emitting unit 10 to the emission surface of the optical sensor 1, and an actuator. The actuator controls the reflection angle of the reflector, thereby scanning the laser light. The scanning direction may be either horizontal or vertical. The scanning unit 20 may also scan the beam by controlling the attitude angle of the housing of the optical sensor 1 itself.

The light receiving unit 30 includes a light receiving lens, a light receiving element unit, and a light receiving circuit. The light receiving lens focuses the light, including the reflected light Br, incident from the outside world onto the light receiving element unit. The light receiving element unit is composed of a plurality of light receiving elements, such as a SPAD (Single Photon Avalanche Diode), that are highly sensitive to light. The light receiving element unit is exposed to light incident from a detection area A, determined by the angle of view of the light receiving unit 30, within the outside world of the light receiving unit 30. The light receiving elements constituting the light receiving element unit are arranged in a two-dimensional array, for example. A set of a plurality of adjacent light receiving elements constitutes a pixel for detecting the reflected light Br. For each of a plurality of scanning lines L corresponding to the reflection angle of the irradiated light Bi by the scanning unit 20, an electrical signal corresponding to the intensity of the light received at each pixel (received light intensity) is output. The electrical signal is output to the light receiving circuit.

The light receiving circuit acquires an electrical signal from the light receiving element unit for each of the background light detection period Pe and the distance measurement period Pr, which are defined in each detection frame. Specifically, during the background light detection period Pe, during which the light receiving element unit is exposed to light while the light emission unit 10 is stopped from intermittently emitting light, an object point in the detection area becomes a reflection point of the background light. As a result, background light, which is light from the outside world reflected by the reflection point, enters the light receiving unit 30 through the incident surface. At this time, the light receiving circuit scans multiple pixels of the light receiving element unit to sense the surrounding light. Here, the setting block 110 in particular can acquire background light data by converting the luminance value acquired for each pixel according to the intensity of the sensed background light into data as each pixel value. The background light data can also be called external light data or ambient light data. The background light detection period Pe is an example of an "illumination stop period". The background light data is an example of "stop data".

On the other hand, during the distance measurement period Pr in which the light receiving unit 30 is exposed to light emitted from the light emitting unit 10, an object point in the detection area becomes a reflection point of the laser light. As a result, the laser light reflected at the reflection point enters the light receiving unit 30 through the incident surface. At this time, the light receiving circuit senses the reflected light Br by scanning multiple pixels of the light receiving element unit.

The light receiving circuit integrates the received light intensity scanned at each pixel for each received light frequency, thereby acquiring the relationship between the flight time of the irradiated light Bi until reception and the received light intensity for each pixel, as shown in Figures 6 and 7. Specifically, the light receiving circuit can acquire histogram information in which the received light intensity is integrated for each predetermined time bin, or waveform information based on the received light intensity for each time bin in the histogram. At this time, the light receiving circuit can eliminate background light during the distance measurement period Pr as noise according to the background light data acquired during the background light detection period Pe, and acquire data on the received light intensity of the reflected light Br for the irradiated light Bi. In addition, the light receiving circuit can acquire the distance to the reflecting object according to the flight time by converting the flight time at the peak of the received light intensity for each pixel into the distance from the optical sensor 1 to the target T.

The autonomous transport vehicle 2 may be equipped with an external sensor other than the optical sensor 1. The external sensor other than the optical sensor 1 may be at least one type of sensor, such as a camera, a millimeter wave radar, or a sonar.

The control unit 100 is connected to the light emitting unit 10, the scanning unit 20, and the light receiving unit 30 via at least one of the following: a LAN (Local Area Network) line, a wire harness, an internal bus, and a wireless communication line. The control unit 100 is configured to include, for example, at least one dedicated computer.

The dedicated computer constituting the control unit 100 may be a sensor ECU that controls the optical sensor 1. The dedicated computer constituting the control unit 100 may be a planning ECU (Electronic Control Unit) that plans a target trajectory along which the autonomous transport vehicle 2 travels. The dedicated computer constituting the control unit 100 may be a trajectory control ECU that causes the actual trajectory to follow the target trajectory of the autonomous transport vehicle 2. The dedicated computer constituting the control unit 100 may be an actuator ECU that controls each electric actuator of the autonomous transport vehicle 2, etc.

The dedicated computer constituting the control unit 100 may be a locator ECU that estimates the self-state quantity of the autonomous transport vehicle 2. The dedicated computer constituting the control unit 100 may be a computer other than the autonomous transport vehicle 2 that constitutes, for example, an external center or a mobile terminal capable of communicating with the autonomous transport vehicle 2.

The dedicated computer constituting the control unit 100 has at least one memory 101 and one processor 102. The memory 101 is at least one type of non-transitory tangible storage medium, such as a semiconductor memory, a magnetic medium, or an optical medium, that non-temporarily stores computer-readable programs and data. Here, storage may be accumulation in which data is retained even when the autonomous transport vehicle 2 is turned off, or temporary storage in which data is erased when the autonomous transport vehicle 2 is turned off. The processor 102 includes at least one type of core, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a RISC (Reduced Instruction Set Computer)-CPU, a DFP (Data Flow Processor), or a GSP (Graph Streaming Processor).

In the control unit 100, the processor 102 executes a plurality of instructions contained in a data processing program stored in the memory 101 in order to process the detection data generated by the optical sensor 1. In this way, the control unit 100 constructs a plurality of functional blocks for controlling the autonomous guided vehicle 2. The multiple functional blocks constructed in the control unit 100 include a setting block 110, an acquisition block 120, and an output block 130, as shown in FIG. 3. The control unit 100 is an example of a "data processing device".

The data processing method in which the control unit 100 processes the detection data generated by the optical sensor 1 by cooperation of these

blocks

110, 120, and 130 is executed according to the data processing flow shown in FIG. 4. This processing flow is executed repeatedly while the optical sensor 1 is running. Note that each "S" in this processing flow represents multiple steps executed by multiple commands included in the data processing program.

First, in S10, the acquisition block 120 acquires background light data for the background light detection period Pe for each individual pixel on one scanning line L in the ranging frame Fr. Specifically, the acquisition block 120 acquires the background light data as information including the integrated received light intensity obtained by integrating the received light intensity over the background light detection period Pe during which the irradiation of the irradiation light Bi is stopped. For example, as shown in FIG. 7, the acquisition block 120 acquires the integrated received light intensity for each predetermined time in the background light detection period Pe as background light data.

In the next step S20, the setting block 110 executes light emission control to emit irradiation light Bi from the light-emitting unit 10 during the distance measurement period Pr following the background light detection period Pe. In the distance measurement frame Fr, the setting block 110 emits irradiation light Bi at a distance measurement light emission intensity Iia, which is a predetermined constant light emission intensity.

In S30, the acquisition block 120 acquires distance measurement data Dr during the distance measurement period Pr from the light receiving unit 30 for each individual pixel on the scan line L. The distance measurement data Dr includes physical information related to the light reception peaks in the reflected light Br when the irradiated light Bi is reflected by the target T. For example, as shown in FIG. 5, the distance measurement data Dr includes at least the light reception time La and light reception intensity Ira of each peak as physical information of the light reception peaks. The background light data acquired in S10 and the distance measurement data Dr acquired in this step become information included in the detection data in the distance measurement frame Fr.

In addition to the reflected light Br, the light receiving unit 30 may receive light irradiated from an external light source 3 as crosstalk light Bc. The external light source 3 may be, for example, another optical sensor mounted on another autonomous vehicle (hereinafter, other vehicle) 4. In this case, the distance measurement data Dr may include a light receiving peak resulting from the reflected light Br and a light receiving peak resulting from the crosstalk light Bc.

Next, in S40, the acquisition block 120 determines whether or not acquisition of detection data has been completed for all scan lines L. If it is determined that acquisition of detection data for all scan lines L has not been completed, the flow returns to S10. This causes acquisition of detection data for each pixel for the next scan line L to be performed.

On the other hand, if it is determined that detection data acquisition has been completed for all scan lines L, the flow proceeds to S50. In S50, the acquisition block 120 acquires background light data for the background light detection period Pe for each pixel of one scan line L in the comparison frame Fc. The background light data includes the integrated received light intensity, for example, similar to the ranging frame Fr.

In the next step S60, the setting block 110 executes light emission control during the distance measurement period Pr following the background light detection period Pe. In the comparison frame Fc, the setting block 110 irradiates the irradiation light Bi at a comparative light emission intensity Iib corresponding to the light reception intensity (crosstalk light reception intensity) of the crosstalk light Bc for each pixel and the light reception intensity of the peak light reception in the distance measurement data Dr in the distance measurement frame Fr.

To go into more detail about the crosstalk light receiving intensity, the setting block 110 first estimates whether crosstalk light Bc is incident from the background light data. Specifically, the setting block 110 determines that crosstalk light Bc is incident when the time-varying width of the light receiving intensity in the background light data is outside the allowable range. For example, as shown in FIG. 7, the setting block 110 performs the determination by using the difference Vd of the integrated light receiving intensity for each time as the time-varying width of the light receiving intensity. Here, the allowable range is a numerical range in which the difference Vd is equal to or less than a threshold value.

Since the irradiation light Bi is not emitted during the background light detection period Pe, if the crosstalk light Bc is not incident, the integrated received light intensity will increase linearly. On the other hand, if crosstalk light Bc is incident from an external light source 3 that periodically and instantaneously emits light, such as another optical sensor, the integrated received light intensity will increase nonlinearly before and after the incidence, as shown in FIG. 8. In other words, the setting block 110 determines whether the increase in the integrated received light intensity is linear or nonlinear based on the difference Vd. The background light data used in this step may be that acquired in the distance measurement frame Fr or that acquired in the comparison frame Fc. Alternatively, the determination results for the background light data of each frame Fr, Fc may be integrated.

When the difference Vd falls outside the allowable range, the setting block 110 determines that crosstalk light Bc is incident and estimates the magnitude of the crosstalk received light intensity from the magnitude of the difference Vd. The larger the difference Vd, the larger the crosstalk received light intensity that the setting block 110 estimates. The setting block 110 may estimate the crosstalk received light intensity from, for example, predetermined relationship information between the difference Vd and the crosstalk received light intensity. Alternatively, the setting block 110 may use the difference Vd as it is as a parameter indicating the crosstalk received light intensity.

To describe in detail the light receiving intensity of the light receiving peak, the setting block 110 acquires the light receiving intensity of the light receiving peak included in the attention distance range as the peak light receiving intensity. The attention distance range is a distance range set according to the distance measurement scene by the optical sensor 1. For example, in the case of this embodiment, when the autonomous transport vehicle 2 is traveling indoors, a distance range relatively close to the optical sensor 1 is set as the attention distance range. Also, when the autonomous transport vehicle 2 is traveling outdoors, a distance range farther than when indoors is set as the attention distance range. When multiple light receiving peaks are detected within the attention distance range, the setting block 110 may calculate the average light receiving intensity of the multiple light receiving peaks. Note that since the distance to the target T correlates with the flight time, i.e., the light receiving timing, the setting block 110 may specify an attention time range corresponding to the attention distance range.

The setting block 110 determines the relative magnitude of the comparative light emission intensity Iib to the ranging light emission intensity Iia based on the above crosstalk light reception intensity and the peak light reception intensity in the ranging data Dr in the ranging frame Fr. For example, the setting block 110 irradiates the corresponding pixel with the comparative light emission intensity Iib of a magnitude determined by the combination pattern shown in Figures 9 and 10.

9 and 10, the crosstalk light receiving intensity and the peak light receiving intensity are classified into three levels, high, medium, and low, and the comparative emission intensity Iib is determined by combining these levels. As shown in the numerical example of FIG. 10, when the peak light receiving intensity is low and medium, the comparative emission intensity Iib is set high relative to the distance measurement emission intensity Iia. That is, the comparative emission intensity Iib is increased so that the light receiving peak within the attention distance range detected in the distance measurement frame Fr does not disappear. On the other hand, when the peak light receiving intensity is high, the comparative emission intensity Iib is set low relative to the distance measurement emission intensity Iia. That is, the comparative emission intensity Iib is decreased so that the light receiving peak within the attention distance range detected in the distance measurement frame Fr does not become saturated. Then, the specific magnitude of the comparative emission intensity Iib is determined so that the light receiving intensity of the reflected light Br in the comparison frame Fc differs from the light receiving intensity of the crosstalk light according to the correspondence relationship between each peak light receiving intensity and the crosstalk light receiving intensity.

In S70, the acquisition block 120 acquires comparison data Dc including physical information related to the light reception peaks in the reflected light Br for the irradiated light Bi irradiated at the comparative emission intensity Iib set in the previous step. The comparison data Dc includes at least the light reception time La and light reception intensity Ira of each peak, similar to the distance measurement data Dr. The background light data acquired in S50 and the comparison data Dc acquired in this step become the information included in the detection data in the comparison frame Fc.

In S80, the output block 130 determines whether the normal condition is satisfied between the distance measurement data Dr and the comparison data Dc for each pixel. The normal condition is that the difference in the intensity ratio between the emission intensity and the light reception intensity at the light reception peak is within the allowable intensity range, and the difference in the light reception timing for the light reception peak is within the allowable time range. Here, the allowable intensity range is the range in which the intensity ratio is equal to or smaller than the threshold value. Also, the allowable time range is the range in which the difference in the light reception timing is equal to or smaller than the threshold value. The allowable time range may be set to a smaller range as the traveling speed of the autonomous guided vehicle 2 is slower. When there are multiple light reception peaks, the output block 130 determines whether the normal condition is satisfied for all light reception peaks. The output block 130 may identify the light reception peak of the comparison data Dc corresponding to a specific light reception peak in the distance measurement data Dr as the light reception peak with the smallest difference in light reception timing from the specific light reception peak.

For example, the light receiving intensity of a particular light receiving peak in the distance measurement data Dr is Ira, the light receiving timing is Ta, and the light receiving intensity of the corresponding light receiving peak in the comparison data Dc is Irb, and the light receiving timing is Tb. When the normal condition is satisfied for the particular light receiving peak, the relationships in the following formulas (1) and (2) are satisfied.
(Equation 1)
|Ira-(Iia/Iib)Irb|≦Ei ... (1)
(Equation 2)
|Ta-Tb|≦Et ... (2)

Note that Ei in formula (1) is the threshold value of the intensity ratio. Et in formula (2) is the threshold value of the difference in light reception timing. Formulas (1) and (2) respectively have the allowable intensity range and allowable time range below the threshold, but as described above, at least one of them may be a range below the threshold. A light reception peak that satisfies the relationship of formula (1), i.e., a light reception peak where the difference in the intensity ratio is within the allowable intensity range, has a light reception intensity in each frame Fr, Fc that correlates with the emission intensity. In other words, there is a relatively high possibility that the light reception peak is derived from the reflected light Br of the irradiated light Bi. Furthermore, there is a relatively high possibility that a light reception peak that satisfies the relationship of formula (2), i.e., a light reception peak where the difference in the light reception timing is within the allowable time range, is derived from the reflected light Br from the same target T. Therefore, a light reception peak for which the normal condition is satisfied is a light reception peak that can be estimated to be derived from the reflected light Br from the same target T.

If it is determined in S80 that the normal condition is met for all light reception peaks of each pixel in one scan line L, the output block 130 adopts the distance measurement data Dr as normal data in which all light reception peaks are derived from reflected light Br.

On the other hand, if it is determined in S80 that there is a light reception peak for which the normal condition is not met, the flow proceeds to S100. For example, the light reception peak with the latest light reception timing in Figures 6 and 7 is a light reception peak for which the difference in intensity ratio falls outside the allowable intensity range and the light reception intensity in each frame Fr, Fc is not correlated with the emission intensity. In S100, the output block 130 generates excluded data by excluding such light reception peaks for which the normal condition is not met from the distance measurement data Dr that contains such light reception peaks as light reception peaks resulting from crosstalk light Bc.

In the next step S110, the output block 130 determines whether the determination of whether the normal conditions are satisfied has been completed for all scan lines L. If it is determined that the determination of whether the normal conditions are satisfied has not been completed, the flow returns to S50. On the other hand, if it is determined in S110 that the determination of whether the normal conditions are satisfied has been completed, the flow proceeds to S120. In S120, the output block 130 generates a distance image by synthesizing the distance measurement data Dr or the excluded data for each pixel for which the normal conditions are satisfied across all scan lines L.

The setting block 110, acquisition block 120, and output block 130 can also be referred to as a setting section, an acquisition section, and an output section, respectively. The output block 130 can also be referred to as an exclusion section.

According to the first embodiment described above, light reception peaks for which the normal conditions are not met in detection data with different light emission intensities are excluded from the distance measurement data. Since the light reception intensity of crosstalk light from other light sources does not depend on the light emission intensity of the optical sensor and the light reception timing can change significantly, light reception peaks for which the normal conditions are not met can be attributed to crosstalk light. Therefore, it is possible to suppress erroneous detection.

Furthermore, according to the first embodiment, the magnitude of the comparative light emission intensity Iib relative to the distance measurement light emission intensity Iia is set. Therefore, a more appropriate comparative light emission intensity Iib can be set for determining whether the normal condition for the light reception peak is satisfied.

Furthermore, according to the first embodiment, when the time-varying width of the received light intensity in the background light data falls outside the allowable range, the magnitude of the comparative emission intensity Iib is set according to the time-varying width. Therefore, the received light intensity of the crosstalk light Bc from the external light source 3 can be estimated from the background light data. Therefore, a more appropriate comparative emission intensity Iib can be set.

In addition, according to the first embodiment, the relative magnitude of the comparative emission intensity Iib is set according to the light receiving intensity of the light receiving peak in the distance measurement data Dr in the distance measurement frame Fr preceding the comparison frame Fc. Therefore, a more appropriate comparative emission intensity Iib for determining whether the normal condition is met for the light receiving peak can be set according to the light receiving intensity of the light receiving peak in the distance measurement frame Fr. Furthermore, in the first embodiment, the relative magnitude of the comparative emission intensity Iib is set according to the light receiving intensity of the light receiving peak included in the attention distance range. Therefore, a more appropriate comparative emission intensity Iib for determining whether the normal condition is met can be set for light receiving peaks in a distance range that requires high attention.

Furthermore, according to the first embodiment, the detection data generated by the optical sensor 1 mounted on the autonomous transport vehicle 2 that transports the transported object as the target T is processed. Such vehicles can have a relatively slow running speed compared to general vehicles that travel on public roads. The slower the running speed of the moving body on which the optical sensor 1 is mounted, the smaller the time difference between the light reception timing in the ranging frame Fr at the light reception peak and the light reception timing in the comparison frame Fc can be. Therefore, the data processing method can be executed by the optical sensor 1 mounted on a moving body that is more suitable for the data processing method in the first embodiment.

Other Embodiments
Although several embodiments have been described above, the present disclosure should not be construed as being limited to those embodiments, and can be applied to various embodiments and combinations within the scope not departing from the gist of the present disclosure.

In a modified example, the optical sensor 1 may be mounted on a vehicle traveling on a public road. In this case, the optical sensor 1 may execute the above-described data processing method within a speed range in which the traveling speed of the vehicle is equal to or less than a threshold value.

In a modified example, the comparison frame Fc corresponding to the ranging frame Fr may be a frame preceding the ranging frame Fr. In this case, the setting block 110 may set the relative magnitude of the comparison light emission intensity Iib to the ranging light emission intensity Iia by directly setting the magnitude of the ranging light emission intensity Iia.

In a modified example, the dedicated computer constituting the control unit 100 may have at least one of a digital circuit and an analog circuit as a processor. Here, the digital circuit is at least one of the following types: ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), SOC (System on a Chip), PGA (Programmable Gate Array), and CPLD (Complex Programmable Logic Device). Such a digital circuit may also have a memory that stores a program.

In addition to the forms described so far, the above-mentioned embodiments and modified examples may be implemented in the form of a processing circuit (e.g., a processing ECU, etc.) or a semiconductor device (e.g., a semiconductor chip, etc.) as a control device that is configured to be mountable on the autonomous transport vehicle 2 and has at least one processor and one memory.

(Additional Note)
This specification discloses the following technical ideas and combinations thereof.

(Technical Concept 1)
A data processing device having a processor (102) for processing detection data generated by an optical sensor (1) that detects a target (T) by receiving reflected light (Br) of irradiation light (Bi) onto a detection area (A), the data processing device comprising:
The processor,
acquiring the detection data including: distance measurement data including physical information regarding a light reception peak in the reflected light received in response to the irradiation light irradiated at a distance measurement light emission intensity that is an emission intensity in a distance measurement frame; and comparison data including the physical information regarding the light reception peak in the reflected light in response to the irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
excluding, from the distance measurement data, the light reception peak for which a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak falls within an allowable intensity range and a difference in light reception timing at the light reception peak falls within an allowable time range is not satisfied between the distance measurement data and the comparison data;
23. A data processing apparatus configured to:

(Technical Concept 2)
The data processing device according to Technical Idea 1, further configured to set a relative magnitude of the comparative emission intensity with respect to the distance measurement emission intensity.

(Technical Concept 3)
The acquiring of the detection data includes:
acquiring stop data including the received light intensity during a period when irradiation of the irradiation light is stopped;
Setting the relative magnitude of the comparative emission intensity includes:
The data processing device according to Technical Idea 2 includes, when a time-varying width of the received light intensity in the stop data falls outside an allowable range, setting a magnitude of the comparative light emission intensity in accordance with the time-varying width.

(Technical Concept 4)
Setting the relative magnitude of the comparative emission intensity includes:
A data processing device according to Technical Idea 2 or Technical Idea 3, which includes setting the relative magnitude of the comparative emission intensity according to the received light intensity of the received light peak in the distance measurement data in the distance measurement frame preceding the comparison frame.

(Technical Concept 5)
Setting the relative magnitude of the comparative emission intensity includes:
The data processing device according to Technical Idea 4, further comprising setting a relative magnitude of the comparative emission intensity in accordance with the received light intensity of the received light peak included within a distance range of interest.

(Technical Concept 6)
A data processing device according to any one of Technical Ideas 1 to 5, which processes the detection data generated by the optical sensor mounted on a transport vehicle that transports the transported object as the target.

In addition, the above technical ideas 1 to 6 may be realized in the form of an optical sensor 1, a method, and a program.

Claims

A data processing device having a processor (102) for processing detection data generated by an optical sensor (1) that detects a target (T) by receiving reflected light (Br) of irradiation light (Bi) onto a detection area (A), the data processing device comprising:
The processor,
acquiring the detection data including: distance measurement data including physical information regarding a light reception peak in the reflected light received in response to the irradiation light irradiated at a distance measurement light emission intensity that is an emission intensity in a distance measurement frame; and comparison data including the physical information regarding the light reception peak in the reflected light in response to the irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
excluding, from the distance measurement data, the light reception peak for which a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak falls within an allowable intensity range and a difference in light reception timing at the light reception peak falls within an allowable time range is not satisfied between the distance measurement data and the comparison data;
23. A data processing apparatus configured to:
The data processing device according to claim 1, further configured to set the relative magnitude of the comparison emission intensity to the ranging emission intensity.
The acquiring of the detection data includes:
acquiring stop data including the received light intensity during a period when irradiation of the irradiation light is stopped;
Setting the relative magnitude of the comparative emission intensity includes:
3. The data processing device according to claim 2, further comprising: when a time-varying width of the received light intensity in the stop data falls outside an allowable range, setting a magnitude of the comparative light emission intensity in accordance with the time-varying width.
Setting the relative magnitude of the comparative emission intensity includes:
3. The data processing apparatus according to claim 2, further comprising setting a relative magnitude of the comparative emission intensity in accordance with the received light intensity of the peak of received light in the distance measurement data in the distance measurement frame preceding the comparison frame.
Setting the relative magnitude of the comparative emission intensity includes:
5. The data processing apparatus according to claim 4, further comprising setting a relative magnitude of the comparative emission intensity in accordance with the received light intensity of the received light peak included within a distance range of interest.
The data processing device according to claim 1, which processes the detection data generated by the optical sensor mounted on the transport vehicle (2) that transports the target object.
An optical sensor that detects a target by receiving reflected light (Br) of irradiation light (Bi) onto a detection area (A) that is reflected by the target (T),
A light-emitting unit (10) that irradiates the irradiation light;
a light receiving unit (30) for receiving the reflected light;
A control unit (100) for acquiring detection data from the light receiving unit;
Equipped with
The control unit
an acquisition unit (120) that acquires the detection data including distance measurement data including physical information regarding a light reception peak in the reflected light received for the irradiation light irradiated at a distance measurement light emission intensity that is an emission intensity in a distance measurement frame, and comparison data including the physical information regarding the light reception peak in the reflected light for the irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
an exclusion unit (130) that excludes from the distance measurement data a light reception peak for which a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak falls within an allowable intensity range and a difference in light reception timing at the light reception peak falls within an allowable time range is not satisfied between the distance measurement data and the comparison data;
An optical sensor having
A data processing method executed by a processor (102) for processing detection data generated by an optical sensor (1) that detects a target (T) by receiving reflected light (Br) of irradiation light (Bi) onto a detection area (A), comprising:
acquiring the detection data including: distance measurement data including physical information regarding a light reception peak in the reflected light received in response to the irradiation light irradiated at a distance measurement light emission intensity that is an emission intensity in a distance measurement frame; and comparison data including the physical information regarding the light reception peak in the reflected light in response to the irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
excluding, from the distance measurement data, the light reception peak for which a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak falls within an allowable intensity range and a difference in light reception timing at the light reception peak falls within an allowable time range is not satisfied between the distance measurement data and the comparison data;
Data processing methods, including:
A data processing program stored in a storage medium (101) for processing detection data generated by an optical sensor (1) that detects a target (T) by receiving reflected light (Br) of irradiation light (Bi) onto a detection area (A), the data processing program including instructions to be executed by a processor (102),
The instruction:
acquiring the detection data including: distance measurement data including physical information regarding a light reception peak in the reflected light received in response to the irradiation light irradiated at a distance measurement light emission intensity that is an emission intensity in a distance measurement frame; and comparison data including the physical information regarding the light reception peak in the reflected light in response to the irradiation light irradiated at a comparative light emission intensity different from the distance measurement light emission intensity in a comparison frame different from the distance measurement frame;
excluding, from the distance measurement data, the light reception peak for which a normal condition that a difference in an intensity ratio between the emission intensity and the light reception intensity at the light reception peak falls within an allowable intensity range and a difference in light reception timing at the light reception peak falls within an allowable time range is not satisfied between the distance measurement data and the comparison data;
A data processing program including: