JP5251858B2 - Laser radar equipment - Google Patents

Description

  The present invention relates to a laser radar device.

  2. Description of the Related Art Conventionally, as a technique related to a laser radar apparatus that detects a distance and an azimuth to a detection object using a laser beam, a laser beam scanning distance measuring apparatus shown in Patent Document 1 below is known. This laser beam scanning type distance measuring device is a regular reflection laser in which, when a laser beam transmitted from a laser beam scanning unit is transmitted in a predetermined scanning angle direction, this laser beam is regularly reflected by a translucent window. A light detection element is provided at a position where light can be detected. When the transmission direction of the laser beam transmitted from the laser beam scanning unit is other than the predetermined scanning angle, if the intensity of the laser beam detected by the photodetection element rises above a predetermined intensity, the translucency It is determined that there is dirt on the window.

Japanese Patent Laid-Open No. 05-223937

  However, in the configuration shown in Patent Document 1, since it is necessary to separately prepare a light receiving means such as a light detection element in order to detect foreign matter attached to the window portion, not only the control becomes complicated, but also the cost is reduced. Miniaturization is difficult. In particular, when the reflected light is received in a relatively short time, it cannot be determined whether the reflected light is due to reflection from a detection object at a near point or from foreign matter adhering to the window. There's a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a laser radar device capable of improving the detection accuracy of a detection object.

  In order to achieve the above object, in the laser radar device according to claim 1, when the laser beam is generated from the laser beam generator and the laser beam generator, A light detecting means for detecting the reflected light reflected by the detection object; and a deflecting means configured to be rotatable about a predetermined central axis. A turning deflection means for deflecting the reflected light transmitted through the window portion toward the light detection means, a driving means for driving the turning deflection means, and the laser. The distance to the detection object is measured based on the detection time from the generation of the laser light by the light generation means until the reflected light reflected by the detection object is detected by the light detection means. A distance measuring means, wherein the distance measuring means is an area of the laser light that is irradiated on the window portion with a foreign matter that adheres to the window portion and suppresses transmission of the laser light. If the amount of reflected light reflected by the foreign object and the detection time are taken as the foreign object reflected light amount and the foreign object reflection time, the detection time corresponds to the foreign object reflection time. Of the reflected light detected at the time when it is detected, the reflected light whose light amount is not less than the first threshold value set lower than the foreign substance reflected light amount and less than the second threshold value set higher than the foreign substance reflected light amount is invalidated And the distance to the detection object is measured based on the detection time of the reflected light whose light quantity is equal to or greater than the second threshold value.

  According to a second aspect of the present invention, in the laser radar device according to the first aspect, the distance measuring means is a third threshold value set lower than the first threshold value in the reflected light having a detection time longer than the foreign object reflection time. The distance to the detection object is measured based on the above.

  According to a third aspect of the present invention, in the laser radar device according to the first or second aspect, the amount of the reflected light detected by the light detection means at a time corresponding to the foreign object reflection time is the first light amount. When it becomes more than 1 threshold value, it has a reporting means which reports adhesion of the foreign matter.

  According to the first aspect of the present invention, when the foreign matter that adheres to the window portion and suppresses the transmission of the laser light adheres larger than the area of the laser light irradiated to the window portion, the reflected light reflected by the foreign matter. The amount of light and the detection time are taken as the amount of foreign object reflection and the time of foreign object reflection. Of the reflected light detected by the light detection means at a time corresponding to the foreign object reflection time, the amount of light is not less than a first threshold set lower than the foreign object reflection light amount, The reflected light that is less than the second threshold value set to be high is invalidated, and the distance to the detection object is measured based on the detection time of the reflected light whose light amount is equal to or more than the second threshold value.

  The reflected light detected at the time corresponding to the foreign object reflection time is either a reflection from a detection object at a near point or a reflection from a foreign substance adhering to the window. The amount of reflected light from a foreign object increases as the foreign object increases, and the amount of reflected light becomes constant when the foreign object becomes larger than the area of the laser light that is irradiated onto the window. It becomes. In general, since the detection object has a higher reflectance than a foreign object adhering to the window, the amount of reflected light from the detection object at the near point is higher than the reflected light from the foreign object.

Therefore, if the amount of reflected light detected at the time corresponding to the foreign object reflection time is equal to or greater than the first threshold and less than the second threshold, it is determined that the reflected light is due to reflection from the foreign matter, In the case where the threshold value is 2 or more, it can be determined that the reflected light is due to reflection from the detection object. Thereby, by invalidating the detection of the reflected light determined to be due to the reflection from the foreign object, it is possible to eliminate the erroneous detection due to the adhesion of the foreign object and to reliably detect the detection object at the near point.
Therefore, even when foreign matter or the like adheres to the window portion, detection of reflected light from the foreign matter can be disabled and detection accuracy of the detected object can be increased.

  In the invention of claim 2, for the reflected light having a detection time longer than the foreign object reflection time, the distance to the detection object is measured by the distance measuring means based on the third threshold set lower than the first threshold.

  Reflected light detected in a detection time longer than the foreign object reflection time is due to reflection from a far-point detection object, not from foreign matter, so there is no need to consider reflection from foreign matter. The threshold for detecting reflected light can be reduced. Therefore, in the detection time longer than the foreign object reflection time, by detecting the reflected light based on the third threshold value, even the reflected light having a light amount lower than the foreign object reflected light amount is detected, thereby further improving the detection accuracy. it can.

  According to a third aspect of the present invention, there is provided an informing means for informing the adhesion of a foreign substance when the amount of reflected light detected at a detection time corresponding to the foreign substance reflection time is equal to or greater than a first threshold value. When the foreign matter adhering to the window increases, the amount of reflected light from the foreign matter becomes equal to or greater than the first threshold value. For this reason, when the amount of reflected light to be detected is equal to or greater than the first threshold value, the user can be urged to remove the foreign matter by notifying the attachment of the foreign matter by the notifying means.

1 is a cross-sectional view schematically illustrating a laser radar device according to an embodiment. It is an expanded sectional view which illustrates the state of the foreign material adhering to a window part. It is a wave form diagram which shows the relationship between the magnitude | size of the foreign material adhering to a window part, and the light reception signal according to the reflected light from the foreign material. It is a flowchart which illustrates the flow of the detection process in a control circuit. It is a wave form diagram which shows the light reception signal according to the reflected light from the far-end detection object. It is a wave form diagram which shows the light reception signal according to the reflected light from the detection object of a near point. It is a wave form diagram which shows the state with which the light reception signal by the reflected light from a foreign material and the light reception signal by the reflected light from the detection object of a near point overlapped. It is a wave form diagram which shows the light reception signal according to the reflected light from the foreign material adhering to a window part. It is a wave form diagram which shows the light reception signal in which a part of laser beam which permeate | transmitted the foreign material was reflected by the detection object, and was received as reflected light.

Hereinafter, an embodiment of a laser radar device according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the laser radar device 1 includes a laser diode 10, a photodiode 20 that receives reflected light L3 from a detection object, and a control circuit 70 that controls the laser diode 10 and the photodiode 20. It is configured as a device that detects the distance and direction to a detection object. The laser diode 10 corresponds to an example of “laser light generation means”, and is supplied with a pulse current from a laser drive circuit (not shown) under the control of the control circuit 70 to project pulsed laser light (laser light L0). To do.

  The photodiode 20 corresponds to an example of “light detection means”, and when the laser light L0 is generated from the laser diode 10, the laser light L0 detects the reflected light L3 reflected by the detection object and receives the light. The signal is converted into a signal and output to the control circuit 70. In addition, about the reflected light from a detection object, the thing of a predetermined area | region is taken in, and in the example of FIG. 1, the reflected light of the area | region between two lines shown with the code | symbol L3 is taken in. .

  A lens 60 and a mirror 30 are provided on the optical axis of the laser beam L0. The lens 60 is configured as a collimating lens, and converts the laser light L0 from the laser diode 10 into parallel light.

  The mirror 30 realizes the transmission of the laser light L0 from the laser diode 10 and the reflection of the reflected light L3 from the detection object side. Specifically, it has a reflection surface 31 that is inclined at a predetermined angle with respect to the optical axis of the laser beam L0, and a through path 32 that intersects the reflection surface 31. In this configuration, the optical axis of the laser light L0 and the optical axis of the reflected light L3 are made to coincide with each other, and the mirror 30 is arranged on the common optical axis and allows the laser light L0 to pass through the through path 32. On the other hand, the reflection surface 31 reflects the reflected light L3 toward the photodiode 20.

  As described above, the lens 60 for converting the laser light L0 into parallel light is provided on the optical path of the laser light L0 from the laser diode 10 to the through path 32. The lens 60 is connected to the through path 32. It is preferable to generate parallel light that allows almost all of the light to pass through. Conversely, when paying attention to the through path 32, the through path 32 may be sized to pass almost all of the laser light L 0 that has been converted into parallel light by the lens 60.

  A rotation deflection mechanism 40 is provided on the optical axis of the laser light L0 that passes through the mirror 30. The rotation deflection mechanism 40 is disposed so as to be rotatable about a central axis extending in the optical axis direction of the laser light L0, and the laser beam L0 is emitted by a concave mirror 41 whose focal position is set on the central axis. The light is reflected toward the space and the reflected light L3 is deflected toward the mirror. The rotation deflection mechanism 40 and the concave mirror 41 correspond to an example of “rotation deflection means” and “deflection means” recited in the claims.

  Further, a motor 50 that rotationally drives the rotation deflection mechanism 40 is provided. The motor 50 corresponds to an example of “driving means”, and is configured to rotate and drive a rotatable concave mirror 41 connected to the shaft 42 by rotating the shaft 42. Here, the motor 50 is constituted by a step motor. Various step motors can be used. If a step motor having a small angle for each step is used, precise rotation is possible. Further, driving means other than the step motor may be used as the motor 50. For example, a servo motor or the like may be used, or a pulsed laser beam may be output in synchronism with the timing when the concave mirror 41 faces the direction in which the distance measurement is desired, and a desired direction can be detected. Good. In this embodiment, as shown in FIG. 1, a rotation angle sensor 52 that detects the rotation angle of the shaft 42 of the motor 50, that is, the rotation angle of the concave mirror 41, is provided. An angle signal corresponding to the rotation angle 41 is output to the control circuit 70. As the rotation angle sensor 52, various types such as a rotary encoder that can detect the rotation angle of the shaft 42 can be used, and the type of the motor 50 to be detected is not particularly limited. Applicable to various types.

  In the present embodiment, the laser diode 10, the photodiode 20, the mirror 30, the lens 60, the rotation deflection mechanism 40, the motor 50, the control circuit 70, and the like are housed in the case 3, and dust and shock protection are achieved. Yes. Around the concave mirror 41 in the case 3, a light guide portion 4 is formed so as to allow the laser light L 0 and the reflected light L 3 to pass therethrough so as to surround the concave mirror 41. The light guide 4 is formed in an annular shape centering on the optical axis of the laser light L0 incident on the concave mirror 41, and is formed over approximately 360 °. The window part 5 which consists of a permeable glass plate etc. is arranged, and dust prevention is achieved.

  The window portion 5 is configured to be inclined over the entire circumference with respect to a virtual plane orthogonal to the optical axis of the laser beam L0 entering the concave mirror 41. In other words, the plate surface is inclined with respect to the laser beam L0 from the concave mirror 41 toward the space. Therefore, even if the laser beam L0 traveling from the concave mirror 41 toward the space is reflected by the window portion 5, it is difficult to become noise light.

  The control circuit 70 is composed of, for example, a microcomputer and a memory (ROM, RAM, EEPROM, etc.), and detects the distance and direction to the detection object by controlling the laser diode 10 and the photodiode 20 described above. It has a function to execute the detection process to be executed by a predetermined computer program.

  A lamp 71 is connected to the control circuit 70 so as to be controllable. The lamp 71 emits light in response to a notification signal from the control circuit 70, thereby functioning as a notification means for visually informing that effect when a foreign substance D described later is detected. Instead of the lamp 71, for example, a buzzer or the like may be employed as the notification means.

Next, detection processing in the control circuit 70 of the laser radar device 1 according to the present embodiment will be described.
In this detection process, as illustrated in FIG. 2, the threshold for detecting reflected light is changed in order to invalidate the detection of reflected light from foreign matter D such as dirt attached to the window 5.

First, the principle of the main detection process for invalidating the detection of reflected light from the foreign matter D will be described.
As illustrated in FIG. 2, when the foreign matter D adheres to the window portion 5 so as to suppress the transmission of the laser light L0 from the concave mirror 41, a part of the laser light L0 is reflected in the case 3 as reflected light. In this case, as illustrated by the solid line in FIG. 3, a light reception signal corresponding to the reflected light detected in a relatively short detection time from the output of the laser light L0 is output from the photodiode 20. When this detection time is defined as a foreign object reflection time Ts, the amount of reflected light detected at the foreign object reflection time Ts increases as the adhered foreign substance D increases (see the wavy line in FIG. 3). When the foreign matter D becomes larger than the area of the laser light L0 applied to the window 5, the amount of reflected light detected because the amount of reflection becomes constant (hereinafter also referred to as foreign matter reflected light amount Ls). )

  The reflected light detected at the time corresponding to the foreign object reflection time Ts after the irradiation with the laser beam L0 is due to reflection from the foreign substance D adhering to the window part 5 as described above, or close to the window part 5. This is either due to reflection from the detected object at the point. In general, since the detection object has a higher reflectance than the foreign object D adhering to the window portion 5, the amount of reflected light from the detection object at the near point is higher than the amount of reflected light from the foreign object D. Therefore, in this embodiment, in order to invalidate the detection of the reflected light from the foreign substance D and to enable the detection of the reflected light from the detection object, a predetermined threshold value compared with the light reception signal from the photodiode 20 is detected. Change according to time.

  Hereinafter, a specific flow of the detection process will be described with reference to the flowchart of FIG. In the following detection processing, it is assumed that the concave mirror 41 is rotating at a constant speed by the rotation of the motor 50 that is driven and controlled by the control circuit 70. Further, it is assumed that the foreign object reflection time Ts and the foreign object reflection light amount Ls are measured in advance for each measurement direction and stored in the memory or the like of the control circuit 70, respectively.

  First, in step S101, a laser emission process is performed. In this process, a light emission signal having a predetermined pulse width corresponding to the light emission trigger generated by the timing signal generator is output to the laser drive circuit. As a result, the laser driving circuit controls the driving, and the laser diode 10 outputs a pulsed laser beam (laser beam L0) at a time interval corresponding to the predetermined pulse width. The laser light L0 is projected as diffused light having a certain spread angle, and is converted into parallel light by passing through the lens 60. The laser light L0 that has passed through the lens 60 passes through the through path 32 formed in the mirror 30, enters the concave mirror 41, is reflected as parallel light by the concave mirror 41, and is irradiated toward the space.

  Next, in step S103, a laser light receiving process is performed. When the laser light L0 is reflected as reflected light by the detection object or the like, the reflected light is collected by the concave mirror 41 and reflected toward the photodiode 20 via the mirror 30. Thus, in the laser light receiving process, a light reception signal corresponding to the reception of the reflected light is input from the photodiode 20 to the control circuit 70.

  Subsequently, in step S105, the amplitude A of the light reception signal from the photodiode 20 is set to a threshold value (hereinafter also referred to as a far point detection threshold Af) that is set to be a predetermined amount smaller than a value corresponding to the foreign matter reflected light amount Ls in the measurement direction. It is determined whether or not it is above. Here, if the amplitude A of the received light signal is less than the far point detection threshold Af (No in S105), it is determined that the reflected light is not received, and the processing from step S101 is repeated. The far point detection threshold Af is set smaller than a foreign object detection threshold Ad described later in order to increase the detection accuracy by making it possible to detect the reflected light from the farther point detection object. When the amplitude A of the received light signal becomes equal to or greater than the far point detection threshold Af, it is determined as Yes in step S105 because the reflected light is received.

  Next, in step S107, it is determined whether or not the time from the output of the laser light L0 until the reflected light is received as described above (hereinafter also referred to as detection time T) is within a predetermined time range ΔT. The Note that the predetermined time range ΔT is a time that can correspond to the foreign object reflection time Ts in order to determine whether or not the received light signal is due to reflection from the foreign object D. It is set to have a predetermined time width.

  Here, as illustrated in FIG. 5, when the detection time T when the amplitude A of the received light signal is not less than the far point detection threshold Af is not within the predetermined time range ΔT, that is, a predetermined time than the foreign object reflection time Ts. In the case where it is longer than this, it is determined that this reflected light is due to reflection from the far-point detection object and not due to reflection from the foreign matter D. In this case, it is determined No in step S107, the far point distance measurement process is performed in step S109, and the distance to the detected object is measured based on the detection time T detected according to the far point detection threshold Af. Is done. Information on the distance measured in this way is output to an external device (not shown) together with information about the rotation angle of the shaft 42, that is, the direction of the detected object, by the output processing in step S111. The control circuit 70 that executes Step S109 and Step S115 described later can correspond to an example of “distance measuring means” described in the claims.

  On the other hand, if the detection time T is within the predetermined time range ΔT (Yes in S107), in step S113, the amplitude A of the received light signal is greater than the value corresponding to the foreign matter reflected light amount Ls in the measurement direction. A determination is made as to whether or not the value is greater than or equal to a threshold (hereinafter referred to as a near point detection threshold An) that is set to be a large amount. Here, as illustrated in FIG. 6, when the amplitude A of the received light signal is equal to or greater than the near point detection threshold An, the amount of reflected light from the foreign matter D does not exceed the amount of reflected foreign matter Ls. It is determined that this is due to reflection from the detection object at the near point and not due to reflection from the foreign matter D. In this case, Yes is determined in step S113, the near point distance measurement process is performed in step S115, and the distance to the detected object is measured based on the detection time detected according to the near point detection threshold value An. The The distance measured in this manner is output in step S111 and output to an external device or the like.

  Thus, for example, as illustrated in FIG. 7, even when the light reception signal by the reflected light from the foreign object D and the light reception signal by the reflected light from the detection object at the near point overlap, it corresponds to the foreign matter reflected light amount Ls. Since the reflected light is detected based on the near point detection threshold value An set larger than the value to be detected, the reflected light from the near point detection object can be detected.

  On the other hand, if the amplitude A of the received light signal is not equal to or greater than the near point detection threshold An in step S113 (No in S113), the amplitude A is a value corresponding to the foreign matter reflected light amount Ls in the measurement direction in step S117. It is determined whether or not it is equal to or greater than a threshold value (hereinafter referred to as a foreign object detection threshold value Ad) set to be a predetermined amount smaller than the threshold value. As described above, the foreign object detection threshold Ad is set to be larger than the far point detection threshold Af, and when the amplitude A of the received light signal is greater than or equal to the foreign object detection threshold Ad as illustrated in FIG. It is determined that this is due to reflection from the light source, and it is determined Yes in step S117.

  When it is determined that the reflected light is from the foreign matter D in this way, a notification process is performed in step S119, and a notification signal is output to the lamp 71. Thereby, the lamp 71 emits light in a predetermined state, so that it is notified that the foreign matter D is attached to the window portion 5, and the detection of the reflected light is invalidated.

  In step S121, it is determined whether or not the light reception signal from which the reflected light from the foreign object D is detected includes a signal corresponding to the reception of the reflected light from the detected object as described above. That is, it is determined whether or not a part of the laser beam L0 that has passed through the foreign matter D is reflected by the detection object and received as reflected light. As illustrated in FIG. In the case where the detection time T when becomes more than the far point detection threshold Af is on the far point side from the predetermined time range ΔT, it is determined as Yes in step S121. In step S109, the distance to the detection object is measured for the far-side light reception signal. Thereby, even if the foreign substance D adheres to the window part 5, the distance to the far-off detection object can be measured.

  On the other hand, when the amplitude A of the received light signal is not equal to or greater than the foreign object detection threshold Ad in step S117 (No in S117), the notification process is not performed because the reflected light from the foreign object D is not large enough to be notified. Thus, the detection of the reflected light is invalidated, and the processing after step S121 is performed.

  As described above, in the laser radar device 1 according to the present embodiment, among the reflected light detected by the photodiode 20 that the detection time T is within the predetermined time range ΔT, the received light signal corresponding to the light amount is detected. Reflected light whose amplitude A is greater than or equal to the foreign object detection threshold Ad set lower than the foreign object reflected light amount Ls and less than the near point detection threshold An set higher than the foreign object reflected light amount Ls is invalidated, and the amplitude A is detected as a near point. The distance to the detection object is measured based on the detection time T of the reflected light that is equal to or greater than the threshold value An.

As a result, the detection of the reflected light determined to be due to the reflection from the foreign matter D is invalidated, thereby eliminating the false detection due to the adhesion of the foreign matter D and reliably detecting the detection object at the near point. it can.
Therefore, even when foreign matter D or the like adheres to the window portion 5, detection of the reflected light from the foreign matter D can be disabled and the detection accuracy of the detected object can be increased.

  Further, in the laser radar device 1 according to the present embodiment, the reflected light of the detection time not within the predetermined time range ΔT, that is, the reflected light of the detection time longer than the foreign object reflection time Ts is lower than the foreign object detection threshold Ad. Based on the set far point detection threshold Af, the distance to the detected object is measured.

  Thereby, in the detection time longer than the foreign object reflection time by a predetermined time or more, the reflected light is detected based on the far point detection threshold Af, so that even the reflected light having a light quantity lower than the foreign object reflected light quantity Ls is detected. The accuracy can be further increased.

  Furthermore, in the laser radar device 1 according to the present embodiment, when the amplitude A of the received light signal corresponding to the amount of reflected light detected at the detection time T corresponding to the foreign object reflection time Ts is equal to or greater than the foreign object detection threshold Ad. A lamp 71 is provided as a notification means for notifying the adhesion of the foreign matter D. Thereby, when the amplitude A of the received light signal is equal to or larger than the foreign object detection threshold Ad, the user can be prompted to remove the foreign object D by notifying the attachment of the foreign object D by the lamp 71.

In addition, this invention is not limited to the said embodiment, You may actualize as follows, and even in that case, an effect | action and effect equivalent to the said embodiment are acquired.
(1) In step S107, the detection time T is not limited to determining whether or not the detection time T is within the predetermined time range ΔT, but is the time threshold set to be equivalent to the foreign object reflection time Ts or less? It may be determined whether or not. In this case, the case where the detection time T is equal to or less than the time threshold corresponds to the case where the detection time T is within the predetermined time range ΔT.

(2) By eliminating step S117, the reflected light having the detection time T within the predetermined time range ΔT and the amplitude A of the received light signal is not less than the far point detection threshold Af and less than the near point detection threshold An is received. In all cases, the notification process may be performed in step S119. Thereby, the adhesion | attachment can be alert | reported also with the smaller foreign material D. FIG.

DESCRIPTION OF SYMBOLS 1 ... Laser radar apparatus 3 ... Case 5 ... Window part 10 ... Laser diode (laser beam generation means)
20 ... Photodiode (light detection means)
40... Turning deflection mechanism (turning deflection means)
50. Motor (driving means)
70 ... Control circuit (distance measuring means)
71: Lamp (notification means)
Ad: Foreign object detection threshold (first threshold)
Af ... Far point detection threshold (third threshold)
An: Near-point detection threshold (second threshold)
D ... Foreign matter Ls ... Foreign matter reflected light amount T ... Detection time Ts ... Foreign matter reflection time

Claims (3)

Laser light generating means for generating laser light;
A light detecting means for detecting reflected light reflected by a detection object when the laser light is generated from the laser light generating means;
The reflected light includes a deflecting unit configured to be rotatable about a predetermined central axis, deflects the laser light toward the space through the window by the deflecting unit, and transmits the reflected light through the window. Rotating deflection means for deflecting the light toward the light detection means;
Drive means for driving the rotation deflection means;
The distance to the detection object is determined based on the detection time from the generation of the laser light by the laser light generation means until the reflected light reflected by the detection object is detected by the light detection means. A distance measuring means for measuring;
A laser radar device comprising:
The distance measuring means includes
When a foreign matter that adheres to the window portion and suppresses the transmission of the laser light adheres larger than the area of the laser light irradiated to the window portion, the amount of reflected light reflected by the foreign matter and the detection When the time is taken as the amount of foreign object reflection and the time of foreign object reflection,
Of the reflected light detected by the light detection means at a time corresponding to the foreign object reflection time, the amount of the reflected light is not less than a first threshold set lower than the foreign object reflected light amount, and the foreign object reflected light amount. The reflected light that is less than the second threshold set higher is invalidated, and the distance to the detection object is measured based on the detection time of the reflected light that is greater than or equal to the second threshold. Laser radar device.   The distance measuring unit measures a distance to the detection object based on a third threshold value set lower than the first threshold value for reflected light having a detection time longer than the foreign object reflection time. Item 2. The laser radar device according to Item 1.   And a notification means for notifying the adhesion of the foreign matter when the amount of the reflected light detected by the light detection means at a time corresponding to the detection time corresponding to the foreign matter reflection time is equal to or greater than the first threshold value. The laser radar device according to claim 1 or 2, characterized in that:

Images