JP2010204015A - Laser radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser radar device with detection accuracy enhanced on a measured distance to a detected body without causing the upsizing of the device. <P>SOLUTION: When a light introduction part 75 exists on an optical axis of laser light L0, part of the laser light L0 is guided by an optical fiber 74 to outgo to a photodiode 20. Further, a distance correcting value Xc is calculated according to a light guiding time T and a distance Xf in a light guiding direction, the guiding time T being between when laser light L0 is generated in a laser diode 10 and when part of the laser light L0 is guided by the optical fiber 74 and detected by the photodiode 20. A measured distance X is corrected based on the correcting value Xc. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser radar device.

  Conventionally, as a technique related to a laser radar apparatus, a laser distance measuring apparatus shown in Patent Document 1 below is known. This laser distance measuring device irradiates light to a reference object provided in the device and is calculated based on the arrival time of reflected light from the reference object, and a preset distance to the reference object Are compared to detect a distance measurement error, and the measurement distance is corrected based on the distance measurement error.

Japanese Patent Laid-Open No. 10-0200356

  However, in the configuration shown in Patent Document 1, it is necessary to increase the distance from the irradiation unit or the light receiving unit to the reference object in order to increase the detection accuracy of the distance measurement error. For this reason, it is necessary to enlarge the apparatus, and there is a problem in that miniaturization and weight reduction of the apparatus are hindered. Further, when downsizing the apparatus, there is a problem that the distance to the reference object cannot be made sufficiently long and the detection accuracy of the distance measurement error cannot be sufficiently increased.

  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 that can improve the detection accuracy of a measurement distance to a detection object without causing an increase in size of the device. There is to do.

  In order to achieve the above object, in the laser radar device according to claim 1, when the laser light is generated from the laser light generating means for generating laser light and the laser light generating means, 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, and directing the laser light to the space by the deflecting means. A rotation deflection means for deflecting the reflected light toward the light detection means, a drive means for driving the rotation deflection means, and the generation of the laser light by the laser light generation means. Distance measuring means for measuring the distance to the detection object based on the time until the reflected light reflected by the detection object is detected by the light detection means. A light guide member that guides a part of the laser light from the laser light generation means and emits the light to the light detection means, and generates the laser light from the laser light generation means. Correction value calculation means for calculating a distance correction value according to a light guide time and a light guide direction distance of the light guide member until a part of light is guided by the light guide member and detected by the light detection means. And distance correction means for correcting the distance to the detected object detected by the distance measurement means based on the distance correction value calculated by the correction value calculation means.

  According to a second aspect of the present invention, in the laser radar device according to the first aspect, the light guide member is an optical fiber.

  According to a third aspect of the present invention, in the laser radar device according to the first or second aspect, the light guide member is arranged in a spiral shape.

  According to a fourth aspect of the present invention, in the laser radar device according to any one of the first to third aspects, the light guide member is configured such that a part of the laser light deflected by the deflecting unit is in a light guide direction. The light guide member is guided at one end and emitted from the other end in the light guide direction toward the light detection means.

  According to a fifth aspect of the present invention, in the laser radar device according to any one of the first to third aspects, a part of the laser beam deflected by the deflection unit is guided in a light guide direction. The light is guided into the light guide member at one end and emitted from the other end in the light guide direction toward the deflecting unit and deflected toward the light detecting unit by the deflecting unit. It is characterized by that.

  According to a sixth aspect of the present invention, in the laser radar device according to any one of the first to third aspects, the light guide member is configured such that a part of the laser light deflected by the deflecting unit is in a light guide direction. The light is guided into the light guide member at one end and reflected by a reflecting portion provided at the other end in the light guide direction, and guided in the reverse direction in the light guide member, and is one end in the light guide direction. The light is emitted toward the deflecting unit and is deflected toward the light detecting unit by the deflecting unit.

  A seventh aspect of the present invention is the laser radar device according to any one of the first to fourth aspects, wherein the inner diameter of the laser detecting device is tapered toward the light detecting means on the light receiving side of the light detecting means. A first cover is provided, and the light guide member emits a part of the laser beam toward an inner peripheral surface of the first cover.

  According to an eighth aspect of the present invention, in the laser radar device according to any one of the first to fourth aspects, on the light receiving side of the light detection means, the inner diameter is reduced stepwise toward the light detection means. A second cover is provided, and the light guide member emits a part of the laser beam toward an inner peripheral surface of the second cover.

  A ninth aspect of the present invention is the laser radar device according to any one of the first to eighth aspects, wherein the light reception waveform of the emitted light from the light guide member detected by the light detection means detects the light reception state. A time difference between a time when the light reception waveform is equal to or greater than a predetermined threshold and a time when the light reception waveform is equal to or less than the predetermined threshold, and the light guide time and the light guide direction detected according to the light reception waveform A map creation unit that creates a correction map by obtaining a relationship with the distance correction value calculated according to the distance for each received light waveform whose light reception sensitivity has been changed, and the distance correction unit includes the distance correction unit Based on the distance correction value set according to the correction map from the time difference in the light reception waveform of the reflected light received by the light detection means, the distance to the detection object detected by the measurement means. to correct And wherein the door.

  A tenth aspect of the present invention is the laser radar device according to the ninth aspect, comprising a plurality of the light guide members each having a different light transmittance, wherein the map creation means is configured to detect each of the light detection means. The correction map is created by obtaining the relationship between the time difference and the distance correction value in the light reception waveform of the light emitted from the light guide member for each light reception waveform whose light reception sensitivity is changed.

  According to an eleventh aspect of the present invention, in the laser radar device according to the ninth or tenth aspect of the present invention, the map creating means receives the received light waveform corresponding to a range in which the distance correction value changes in accordance with a change in the time difference. The sensitivity is changed.

  In the first aspect of the invention, a part of the laser light from the laser light generating means is guided by the light guide member and emitted to the light detecting means. Further, the correction value calculating means guides the light guide time from the generation of the laser light by the laser light generating means until a part of the laser light is guided by the light guide member and detected by the light detecting means, and the light guide. A distance correction value is calculated according to the light guide direction distance of the member. Then, the distance correction unit corrects the distance to the detected object detected by the distance measurement unit based on the distance correction value calculated by the correction value calculation unit.

As a result, a part of the laser light is guided in the light guide member and reliably emitted to the light detection means, and, for example, the light guide member is arranged in a curved manner at a plurality of locations in the apparatus. Since the light guide direction distance of the light guide member becomes longer, the detection accuracy of the distance correction value can be increased.
Therefore, it is possible to increase the detection accuracy of the measurement distance to the detection object without increasing the size of the apparatus.

  In the invention of claim 2, since an optical fiber is adopted as the light guide member, it is easy to bend and arrange in the apparatus, and light guided into the light guide member is reliably detected by light. Can be emitted.

  In the invention of claim 3, since the light guide member is arranged in a spiral shape, the space occupied by the light guide member in the device is reduced, and the light guide member having a long light guide direction distance is provided. An increase in the size of the apparatus can be suppressed.

  In the invention of claim 4, a part of the laser beam deflected by the deflecting means by the light guide member is guided into the light guide member at one end portion in the light guide direction and the other end in the light guide direction. The light is emitted from the unit toward the light detection means.

  When one end of the light guide direction is arranged between the laser light generating means and the deflecting means, and a part of the laser light from the laser light generating means is guided into the light guide member through the one end of the light guide direction Regardless of the rotational position of the deflection means, one end of the light guide direction always affects the laser beam directed to the detection object.

  Therefore, by guiding a part of the laser beam deflected by the deflecting means into the light guide member via the one end portion in the light guide direction, one end of the light guide direction is provided only when the deflecting means is located at a predetermined rotational position. Since the portion affects the laser light directed toward the detection object, the influence on the laser light due to the provision of the one end portion in the light guide direction can be suppressed.

  In the invention of claim 5, a part of the laser beam deflected by the deflecting means by the light guide member is guided into the light guide member at one end portion in the light guide direction and the other end in the light guide direction. The light is emitted from the portion toward the deflecting means and is deflected toward the light detecting means by the deflecting means.

  Even in this case, the light guide direction one end and the light guide direction other end affect the laser beam toward the detection object only when the deflecting means is located at the predetermined rotation position. The influence on the laser beam due to the provision of the other end in the direction can be suppressed.

  In the invention of claim 6, a part of the laser light deflected by the deflecting means by the light guide member is guided into the light guide member at one end portion in the light guide direction and the other end in the light guide direction. The light is reflected by a reflecting portion provided in the light guide portion, guided in the reverse direction in the light guide member, emitted from one end portion in the light guide direction toward the deflecting means, and deflected toward the light detecting means by the deflecting means. The

  Even in this case, only when the deflecting means is located at the predetermined rotation position, the one end portion in the light guide direction affects the laser light directed toward the detection object. Can be suppressed. In particular, since a part of the laser light is guided at one end portion in the light guide direction and emitted from the light guide member, a part of the laser light is transmitted from the other end portion in the light guide direction as in the invention of claim 5. Compared with the case where it emits toward the deflecting means, it is possible to eliminate the influence of the other end portion in the light guide direction on the laser beam toward the detection object.

  In the invention of claim 7, the first cover whose inner diameter is tapered toward the light detecting means is provided on the light receiving side of the light detecting means. And a light guide member radiate | emits a part of laser beam toward the internal peripheral surface of a 1st cover.

  The laser light emitted from the laser light generating means is set to a very high light intensity in order to receive reflected light from a detection object far away from the apparatus. For this reason, even when only a part of the laser beam is received by the light detection means via the light guide member, the light reception waveform output from the light detection means is saturated due to the high light intensity. In some cases, the accurate light guide time cannot be detected.

  Therefore, by reflecting the light emitted from the light guide member on the inner peripheral surface of the first cover and receiving only a part of the light by the light detection means, the light detection means Since the intensity of the received light is suppressed, it is possible to suppress the saturation of the received light waveform output from the light detection means according to this light.

  According to the eighth aspect of the present invention, the second cover whose inner diameter is reduced stepwise toward the light detecting means is provided on the light receiving side of the light detecting means. And a light guide member radiate | emits a part of laser beam toward the internal peripheral surface of a 2nd cover.

  Even in this case, similarly to the seventh aspect of the invention, the light emitted from the light guide member is reflected by the inner peripheral surface of the second cover, and only a part thereof is received by the light detecting means. Therefore, since the intensity of the light received by the light detection unit is suppressed, saturation of the light reception waveform output from the light detection unit according to this light can be suppressed. In particular, the laser light from the detection object via the deflecting means is also reflected by the inner peripheral surface of the second cover and only a part thereof is received by the light detecting means. Can be suppressed.

  According to the ninth aspect of the present invention, the time when the received light waveform of the light emitted from the light guide member detected by the light detecting means becomes equal to or greater than a predetermined threshold by the map creating means and the received light waveform falls below the predetermined threshold. The relationship between the time difference between the time and the distance correction value calculated according to the light guide time detected according to the light reception waveform and the light guide direction distance for each light reception waveform with the light reception sensitivity changed. Thus, a correction map is created. The distance correction means converts the distance to the detection object detected by the distance measurement means to a distance correction value set according to the correction map from the time difference in the light reception waveform of the reflected light received by the light detection means. Correct based on.

  When the light intensity of the reflected light received by the light detection means is high, the light reception waveform output from the light detection means is saturated, and an accurate distance correction value cannot be calculated. Therefore, when the received light waveform is saturated, the time difference becomes longer, so this time difference and a distance correction value corresponding to the time difference are created in advance as a correction map, and the distance to the detected object is corrected from the time difference. Correction is performed based on a distance correction value set according to the map. As a result, even when the light reception waveform is saturated, the distance correction value is set based on the correction map that takes into account the saturation state of the light reception waveform, so that the detection accuracy of the distance correction value is increased, and the measurement distance to the detected object is increased. Detection accuracy can be increased.

  In the invention of claim 10, a plurality of light guide members having different light transmittances are provided. Then, the map creation means obtains the relationship between the time difference and the distance correction value in the light reception waveform of the emitted light from each light guide member detected by the light detection means for each light reception waveform whose light reception sensitivity has been changed, Create a correction map.

  In the case where only one light guide member is provided, a set of time difference and distance correction value is calculated every time the deflecting means rotates once, so that the accuracy of the distance correction value using the correction map is increased. Therefore, a plurality of sets of time differences and distance correction values are required, and it takes time to create a correction map.

  Therefore, by providing a plurality of light guide members having different light transmittances, a time difference and a distance correction value for the number of light guide members are calculated each time the deflecting unit rotates once. The time for creation can be shortened.

  In the invention of claim 11, since the light receiving sensitivity of the light receiving waveform is changed corresponding to the range in which the distance correction value changes according to the change in time difference, the map creating means is not saturated with the light receiving waveform. Since the time difference and distance correction value in the range where the correction value does not change according to the time difference change are not calculated, the calculation of the time difference and distance correction value unnecessary for creating the correction map is eliminated, The time for creating a map can be reduced.

1 is a cross-sectional view schematically illustrating a laser radar device 1 according to a first embodiment. It is an expanded sectional view which shows the condensing part 70 of FIG. It is an expanded sectional view which shows the light introduction part 75 of FIG. It is sectional drawing which shows the AA cross section of FIG. It is a block diagram which shows the electrical structure regarding the distance measurement process of the control circuit 80 of FIG. It is a flowchart which illustrates the distance measurement process in the 1st embodiment. It is a waveform diagram showing the relationship of the luminous signals S ₁ and the light receiving signal S _2. It is an expanded sectional view showing condensing part 70a of the 1st modification concerning this 1st embodiment. It is sectional drawing which shows the principal part of the laser radar apparatus 1 which concerns on this 2nd Embodiment. It is a flowchart which illustrates the distance measurement process in the 2nd embodiment. FIG. 11 is a part of a flowchart illustrating a subroutine for correction map creation processing in FIG. 10; FIG. FIG. 11 is a part of a flowchart illustrating a subroutine for correction map creation processing in FIG. 10; FIG. It is a wave form diagram showing an example of the state of the 2nd light reception waveform Sb when propagation light L4 guided by each optical fiber 91-94 is received. It is a wave form diagram showing an example of the state of the 2nd light reception waveform Sb when propagation light L4 guided by each optical fiber 91-94 is received. 5 is a correction map showing a relationship between a correction time difference ΔT and a distance correction value Xc.

[First Embodiment]
Hereinafter, a laser radar device according to a first embodiment of 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 80 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 emits pulsed laser light (laser light L0) when supplied with a pulse current from the laser driving circuit 81 under the control of the control circuit 80. It is.

  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 80. 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 the first 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 of the concave mirror 41 is output to the control circuit 80. 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.

  A condensing unit 70 is disposed between the mirror 30 and the photodiode 20. As shown in FIG. 2, the condensing unit 70 includes a condensing lens 71, a lens holder 72 for holding the condensing lens 71, and a cover 73.

  The cover 73 is disposed on the light receiving side (the condensing lens 71 side) of the photodiode 20 and is formed so that the inner diameter is tapered toward the photodiode 20. Thereby, the cover 73 plays a role of preventing the photodiode 20 from receiving light different from the reflected light L3 collected by the condenser lens 71. The cover 73 corresponds to an example of a “first cover” recited in the claims. Further, the cover 73 and the lens holder 72 may be integrally formed.

  In the first 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 80, and the like are housed in the case 3, and dust and impact protection is achieved. It has been. 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 has an annular shape centered on the optical axis of the laser light L0 incident on the concave mirror 41, and is configured to extend approximately 360 °. The light guide 4 is closed to form a glass plate or the like. A transparent plate 5 made of is arranged to prevent dust.

  The transparent plate 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. That is, 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 transparent plate 5, it is difficult to become noise light.

  As shown in FIG. 1, the case 3 is provided with an optical fiber 74 that has a longer overall length by being spirally arranged. The optical fiber 74 corresponds to an example of a “light guide member”, and the transmittance thereof is sufficiently lower than that in air.

  As shown in FIG. 3, the one end 74 a of the optical fiber 74 is able to guide a part of the laser light L 0 incident on the light introducing portion 75 to the light introducing portion 75 so as to be able to guide the propagation light L 4 into the optical fiber 74. It is attached. As shown in FIGS. 1 and 4, the light introducing portion 75 is disposed on the optical axis of the laser light L0 deflected by the concave mirror 41 located at a predetermined rotational position and in the vicinity of the light guiding portion 4. Yes.

  The light introducing portion 75 includes a half mirror 75 a, and the half mirror 75 a reflects a part (for example, 5%) of the laser light L 0 toward the one end portion 74 a of the optical fiber 74, whereby the optical fiber 74. And the remaining part of the laser beam L0 is transmitted.

  Thereby, the light intensity of the propagation light L4 guided into the optical fiber 74 is suppressed to be sufficiently smaller than the light intensity of the laser light L0. The light introducing unit 75 is not disposed on the optical axis of the laser light L0, but is disposed within the range of the directivity angle of the laser light L0 deflected by the concave mirror 41 so as to emit a part of the laser light L0. The light may be guided to the fiber 74.

  Further, as shown in FIG. 2, the other end 74 b of the optical fiber 74 is a cover that emits the propagating light L4 propagated (guided) in the optical fiber 74 toward the inner peripheral surface 73 a of the cover 73. 73 is attached.

  The light guide direction distance Xf, which is the distance from when the light from the laser diode 10 is deflected by the concave mirror 41 to the optical fiber 74 and received by the photodiode 20, is the total length of the optical fiber 74. It is assumed that the data is preset and stored in the memory of the control circuit 80 or the like.

  The control circuit 80 is composed of, for example, a microcomputer, a memory (ROM, RAM, EEPROM, etc.), etc., and has a function of executing a distance measurement process for measuring the distance to the detected object by a predetermined computer program. . As shown in FIG. 5, the control circuit 80 executes the computer program stored in its internal memory, thereby performing a timing signal generation unit 82, a pulse generation unit 83, an amplification circuit 84, and a distance calculation. It functions as a distance measuring means comprising the unit 85 and the distance correction value calculating unit 86.

  When the timing signal generation unit 82 generates a light emission trigger corresponding to the angle signal from the rotation angle sensor 52 at a predetermined timing (for example, 360 times at 360 °) and outputs it to the pulse generation unit 83, the pulse generation unit 83 Then, a light emission signal having a predetermined pulse width corresponding to the light emission trigger is output to the laser driving circuit 81. The laser drive circuit 81 drives the laser diode 10 according to the light emission signal from the pulse generator 83, so that the laser light L0 is emitted from the laser diode 10 at a predetermined light emission timing.

  The light reception signal output from the photodiode 20 is input to the amplification circuit 84 and amplified by a predetermined gain, and then output to the distance calculation unit 85. The distance calculation unit 85 calculates a time difference, which is a time from the emission of the laser light L0 to the reception of the reflected light L3, according to the synchronization signal from the timing signal generation unit 82, and the measurement distance X calculated from this time difference. Is corrected by the distance correction value Xc set by the distance correction value calculation unit 86.

  The distance correction value calculation unit 86 calculates the light guide time T that is the time from the emission of the laser light L0 to the reception of the propagation light L4 according to the synchronization signal from the timing signal generation unit 82, and the light guide time. A distance correction value Xc is calculated based on T and the light guide direction distance Xf.

  Next, a specific flow of the distance measurement process in the control circuit 80 of the laser radar device 1 according to the first embodiment will be described with reference to the flowchart of FIG. In the following distance measurement 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 80.

First, in step S101, a laser emission process is performed. In this process, a light emission signal S ₁ having a predetermined pulse width corresponding to the light emission trigger generated by the timing signal generator 82 is output from the pulse generator 83 to the laser drive circuit 81. Accordingly, the laser drive circuit 81 is driven and controlled, and pulse laser light (laser light L0) at a time interval corresponding to the predetermined pulse width is output from the laser diode 10. 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 L3 by the detection object, the reflected light L3 is collected by the concave mirror 41 and reflected toward the photodiode 20 via the mirror 30. Thus, the laser light receiving process, the light receiving signal S ₂ corresponding to the received light such as reflected light L3 from the photodiode 20 is inputted is amplified in the distance calculation unit 85 and the distance correction value calculating unit 86 by the amplifier circuit 84.

Then, in step S105, it is determined whether or not the second light reception waveform Sb exists in the region α. When the reflected light L3 from the detection object is received by the photodiode 20, the light receiving signal S ₂ to be input at step S103, and thus to include received waveform corresponding to the received light of as described above reflected light L3 . On the other hand, if the concave mirror 41 the light introducing section 75 on the optical axis of the laser beam L0 to be deflected by the concave mirror 41 to be positioned at a predetermined rotational position exists, the received signal S _2, the first light receiving waveform Sa And the second received light waveform Sb. The first light receiving waveform Sa is received by the photodiode 20 through the concave mirror 41 and the mirror 30 without a part of the laser light L0 reflected by the surface of the light introducing portion 75 being guided through the optical fiber 74. This is a waveform generated as a result. The second received light waveform Sb is received by the photodiode 20 as a part of the laser light L0 reflected by the half mirror 75a of the light introducing section 75 is guided as the propagation light L4 through the optical fiber 74. This is a waveform generated by In addition, when the reflected light L3 from the detection object is received by the photodiode 20 when the light introducing portion 75 exists on the optical axis of the laser light L0, a third light receiving waveform different from the both light receiving waveforms Sa and Sb. There will be included in the light receiving signal S _2. In step S105, based on the angle signal from the rotation angle sensor 52, whether or not the concave mirror 41 is located at a predetermined rotation position (a rotation position where the light introducing portion 75 exists on the optical axis of the laser light L0). You may make it determine.

Since the length of the position and the optical fiber 74 of the light introducing section 75 is constant, the first light receiving waveform Sa and the second light receiving waveform Sb is always present in a certain region in the light receiving signal S _2. Therefore, as shown in FIG. 7, by setting the area where the second light receiving waveform Sb can always present as the region alpha, if there is a second receiver frequency in the region alpha in the light receiving signal S _2, the light receiving the first light receiving waveform Sa and the second light receiving waveform Sb to be included is determined in the signal S _2. Thereby, the reflected light L3 from the detection object and the propagation light L4 guided through the optical fiber 74 can be distinguished.

In step S105 described above, if the second light reception waveform Sb does not exist in the region α, it is determined No, and in step S111, the distance correction value Xc is not updated by the distance correction value update processing described later. A distance calculation process is performed by the calculation unit 85. In this process, the time and the light receiving signal S ₂ is greater than or equal to a predetermined threshold S _t for detecting a light receiving state according to the received light such as reflected light L3 from the photodiode 20 when outputting a laser beam L0 by the laser diode 10 The time difference from the time until is reached is calculated. Then, the measurement distance X is calculated by multiplying the time difference by the speed of light or the like. The control circuit 80 and the distance calculation unit 85 that execute Step S111 correspond to an example of “distance measuring unit” described in the claims.

  Next, distance correction processing is performed in step S113. In this process, the measurement distance X is corrected by subtracting the distance correction value Xc already stored in the memory from the measurement distance X calculated in step S111. Then, the processing from step S101 is repeated. If the distance correction value Xc is not stored in the memory by the process in step S109 described later, the measurement distance X is corrected by setting the distance correction value Xc = 0 (zero). In addition, the control circuit 80 and the distance calculation unit 85 that execute Step S113 correspond to an example of “distance correction unit” described in the claims.

On the other hand, if it is determined that the light introducing unit 75 exists on the optical axis of the laser beam L0 and the second received light waveform exists in the region α (Yes in S105), in step S107, the distance correction value calculating unit 86. Thus, a light guide time calculation process is performed. In this process, in the light receiving signal S ₂ which is input in step S103, time when outputting the laser beam L0 by the laser diode 10, the time at the second receiver frequency Sb until equal to or greater than the threshold value S _t The light guide time T is calculated as the time difference between

  Specifically, when the light introducing portion 75 exists on the optical axis of the laser light L0, a part of the laser light L0 reflected by the half mirror 75a of the light introducing portion 75 is the propagation light L4, and the optical fiber 74. The light is guided through the other end 74 b and emitted from the other end 74 b into the cover 73. As shown in FIG. 2, when the propagation light L4 is emitted so as to diffuse toward the inner peripheral surface 73a of the cover 73, only a part reflected by the inner peripheral surface 73a is received by the photodiode 20. The other part is reflected outward through the condenser lens 71. Thereby, the intensity of light received by the photodiode 20 is suppressed as compared with the case where the propagating light L4 is directly received.

  When the light guide time calculation process is performed in step S107 as described above, the distance correction value update process is performed in step S109. In this process, the distance correction value Xc is calculated by subtracting the light guide direction distance Xf stored in advance in the memory from the correction reference distance obtained by multiplying the light guide time T calculated as described above by the speed of light. Then, the distance correction value Xc stored in the memory is updated according to the calculation result. The control circuit 80 and the distance correction value calculation unit 86 that execute step S109 correspond to an example of “correction value calculation means” described in the claims.

  By correcting the measurement distance X in step S113 based on the updated distance correction value Xc in this way, the correction considering the influence of disturbance, for example, the influence of the delay in the signal of the circuit system due to the influence of the ambient temperature. Thus, the detection accuracy of the measurement distance X can be improved.

  As described above, in the laser radar device 1 according to the first embodiment, when the light introducing portion 75 exists on the optical axis of the laser light L0 by the optical fiber 74, a part of the laser light L0 is generated. The light is guided and emitted to the photodiode 20. Depending on the light guide time T and the light guide direction distance Xf from the generation of the laser light L0 in the laser diode 10 until a part of the laser light L0 is guided by the optical fiber 74 and detected by the photodiode 20. Thus, the distance correction value Xc is calculated. Then, the measurement distance X calculated in step S111 is corrected based on the distance correction value Xc.

As a result, a part of the laser light L0 is guided through the optical fiber 74 and reliably emitted to the photodiode 20, and the optical fiber 74 is arranged in a spiral shape to include the entire length of the optical fiber 74. Since the light guide direction distance Xf becomes longer, the detection accuracy of the distance correction value Xc can be increased.
Therefore, the detection accuracy of the measurement distance X to the detection object can be increased without causing an increase in the size of the apparatus.

  In particular, the optical fiber 74 can be easily bent and disposed in the case 3, and light guided into the optical fiber 74 can be reliably emitted to the photodiode 20. Furthermore, since the optical fiber 74 is arranged in a spiral shape, the space occupied by the optical fiber 74 in the case 3 is reduced, and the large size of the apparatus is obtained by arranging the optical fiber 74 having a long light guide direction distance Xf. Can be suppressed.

  In the laser radar apparatus 1 according to the first embodiment, a part of the laser light L0 deflected by the concave mirror 41 is guided into the optical fiber 74 by the one end 74a by the optical fiber 74. In addition, the light is emitted toward the photodiode 20 from the other end 74b.

  Thereby, since the one end portion 74a and the light introducing portion 75 affect the laser light L0 directed to the detection object only when the concave mirror 41 is located at a predetermined rotational position, the laser light by providing the one end portion 74a and the light introducing portion 75 is provided. The influence on L0 can be suppressed.

  Furthermore, in the laser radar device 1 according to the first embodiment, a cover 73 whose inner diameter is tapered toward the photodiode 20 is provided on the light receiving side of the photodiode 20. The other end 74 b of the optical fiber 74 emits the propagation light L 4 toward the inner peripheral surface 73 a of the cover 73.

As a result, the propagation light L4 emitted from the other end 74b of the optical fiber 74 is reflected by the inner peripheral surface 73a of the cover 73 and only a part thereof is received by the photodiode 20. since the intensity of the propagation light L4 to be received is suppressed Te, it is possible to suppress the saturation of the second light receiving waveform Sb in the light receiving signal S ₂ output from the photodiode 20 in response to the light.

  As a first modification according to the first embodiment, as shown in FIG. 8, a condensing unit 70 a having a cover 76 may be employed instead of the condensing unit 70 having the cover 73 described above. The cover 76 is disposed on the light receiving side (the condensing lens 71 side) of the photodiode 20 and is formed so that the inner diameter thereof decreases in a stepped manner toward the photodiode 20. The other end 74 b of the optical fiber 74 is attached to the lens holder 72 so as to emit the propagation light L 4 toward the inner peripheral surface 76 a of the cover 76 via the condenser lens 71.

Even in this case, similarly to the first embodiment, the propagation light L4 emitted from the other end 74b of the optical fiber 74 is reflected by the inner peripheral surface 76a of the cover 76, and only a part thereof is a photodiode. to be received by 20, since the intensity of the propagating light L4 is received by the photodiode 20 is suppressed, the second light receiving waveform Sb in the light receiving signal S ₂ output from the photodiode 20 in response to the light Can be suppressed. In particular, the reflected light L3 from the detection object via the concave mirror 41 is also reflected by the inner peripheral surface 76a of the cover 76 and only a part thereof is received by the photodiode 20, so that the received light waveform is also measured during distance measurement. Can be suppressed. The cover 76 corresponds to an example of a “second cover” recited in the claims. Further, the cover 76 and the lens holder 72 may be integrally formed.

  As a second modification according to the first embodiment, one end 74 a and the other end 74 b of the optical fiber 74 may be arranged on the optical axis of the laser light L 0 deflected by the concave mirror 41. For this reason, a part of the laser light L0 deflected by the concave mirror 41 by the optical fiber 74 is guided as propagating light L4 into the optical fiber 74 by the one end 74a, and from the other end 74b to the concave mirror. The light is emitted toward 41 and deflected toward the photodiode 20 by the concave mirror 41.

  Even in this case, only when the concave mirror 41 is located at a predetermined rotational position, the one end portion 74a, the light introducing portion 75, and the other end portion 74b affect the laser light L0 toward the detection object. The influence on the laser beam L0 due to the introduction part 75 and the other end part 74b can be suppressed. In particular, since it is not necessary to attach the other end 74 b of the optical fiber 74 to the light collecting unit 70, the space around the photodiode 20 is effectively used as compared with the case where the other end 74 b is attached to the light collecting unit 70. be able to.

  Further, as a third modification according to the first embodiment, the other end portion 74b of the optical fiber 74 is not attached to the condensing portion 70, and a reflection portion is provided at the other end portion 74b, and the reflection portion provides an optical fiber. The propagating light L4 guided in the direction toward the other end 74b in 74 may be reflected in the reverse direction (direction toward the one end 74a).

  For this reason, a part of the laser light L0 deflected by the concave mirror 41 is guided by the optical fiber 74 as the propagation light L4 into the optical fiber 74 at one end 74a and provided at the other end 74b. The light is reflected by the reflecting portion, guided in the opposite direction through the optical fiber 74, emitted from the one end 74 a toward the concave mirror 41, and deflected toward the photodiode 20 by the concave mirror 41.

  Even in this case, only when the concave mirror 41 is located at a predetermined rotational position, the one end 74a affects the laser light L0 directed toward the detection object, so that the laser light L0 is provided by providing the one end 74a and the light introducing portion 75. The influence of can be suppressed. In particular, since a part of the laser light L0 is guided at the one end 74a and emitted from the optical fiber 74, a part of the laser light L0 is changed as in the second modification according to the first embodiment. Compared with the case where the light is emitted from the end 74b toward the concave mirror 41, the influence of the other end 74b on the laser beam L0 directed to the detection object can be eliminated.

[Second Embodiment]
Next, a laser radar device according to a second embodiment of the present invention will be described with reference to FIGS.
In the laser radar device 1 according to the second embodiment, four optical fibers 91 to 94 are employed instead of the optical fiber 74, and the distance measurement process described above is replaced with the flowchart shown in FIG. 12 is different from the laser radar apparatus according to the first embodiment in that the calculation process is performed based on the flowchart shown in FIG. Therefore, substantially the same components as those of the laser radar apparatus of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The optical fibers 91 to 94 have different light transmittances. For example, the optical fibers 91, 92, 93, and 94 have transmittances of 0.1, 0.2, 0.3, and 0.4, respectively. Is set to For this reason, even when the laser light L0 having the same light intensity is guided, the light intensity of the propagation light L4 emitted from each of the optical fibers 91 to 94 is different.

  As shown in FIG. 9, one end of each of the optical fibers 91 to 94 is attached to a light introduction part 75, and each light introduction part 75 is deflected by a concave mirror 41 positioned at a predetermined rotational position. They are arranged on the optical axis of the laser beam L0, at equal intervals in the circumferential direction, and in the vicinity of the light guide 4 respectively. The other end portions of the optical fibers 91 to 94 are attached to the cover 73 so as to be emitted toward the inner peripheral surface 73 a of the cover 73. Moreover, the light guide direction distance Xf in each optical fiber 91-94 is set equal by setting the full length of each optical fiber 91-94 equally. FIG. 9 is a cross-sectional view corresponding to the AA cross section of FIG.

By the way, when the light intensity of the reflected light L3 received by the photodiode 20 is high, the light reception waveform output from the photodiode 20 is saturated, and an accurate distance correction value Xc cannot be calculated. Therefore, when the receiving wave is saturated, since the time difference between the time when time and the light receiving waveform when the receiver frequency is equal to or greater than the predetermined threshold S _t is equal to or less than a predetermined threshold S _t is longer In the second embodiment, the time difference and the distance correction value Xc corresponding to the time difference are created in advance as a correction map, which will be described later, by executing a correction map creation process.

Hereinafter, a specific flow of the distance measurement process in the control circuit 80 of the laser radar device 1 according to the second embodiment will be described with reference to the flowcharts of FIGS.
First, in step S300 of FIG. 10, a correction map creating process subroutine is executed. This correction map creation process is performed immediately after the start of the distance measurement process, and the correction time difference ΔT, which will be described later, is associated with the distance correction value Xc without measuring the distance to the detected object. Create a map. Then, the measurement distance X to the detected object is corrected based on the distance correction value Xc set according to the correction map from the time difference. The control circuit 80 that executes step S300 corresponds to an example of a “map creating unit” recited in the claims.

  In the correction map creating process subroutine, as shown in FIG. 11, first, in step S301, a laser output intensity setting process is performed. In this process, the laser drive circuit 81 is controlled so that the light intensity of the laser light L0 output from the laser diode 10 is increased stepwise. Thereby, the light receiving sensitivity of the light receiving waveform received by the photodiode 20 can be increased stepwise. Note that immediately after the start, the light intensity of the laser light L0 is set to a predetermined low level.

Next, laser light emission processing is performed in step S303, and the laser light L0 is output from the laser diode 10 with the light intensity set in step S301. Then, the laser light receiving process is performed in step S305, it acquires the received signal S ₂ output from the photodiode 20.

Then, in step S307, it is determined whether or not the second light reception waveform Sb exists in the region α. Second light receiving waveform Sb of the light receiving signal S ₂ from the propagation light L4 is guided to one of the optical fibers 91-94 is received by the photodiode 20 for the concave mirror 41 is located at the predetermined rotational position If it exists in the region α, it is determined Yes in step S307. If the second light reception waveform Sb does not exist in the region α (No in S307), the processing from step S303 is repeated.

Subsequently, in step S309, a correction time difference calculation process is performed. In this process, the time and when the second light receiving waveform Sb is equal to or higher than the predetermined threshold S _t, the correction time difference is a time difference between the time when the second light receiving waveform Sb is equal to or less than a predetermined threshold S _t ΔT is calculated.

In step S311, distance correction value calculation processing is performed. In this process, in the light receiving signal S _2, the time and the time of outputting a laser beam L0 by the laser diode 10, the time and the light receiving waveform when in the second light receiving waveform Sb becomes more above a predetermined threshold S _t wherein calculating a time difference between the time corresponding to the average value of the time when less than or equal to a certain threshold S _t. Then, the distance correction value Xc is calculated by subtracting the light guide direction distance Xf stored in advance in the memory from the correction reference distance obtained by multiplying the time difference by the speed of light. For example, the distance correction value Xc is calculated based on the time difference between the time when the laser light L0 is output by the laser diode 10 and the time until the second light receiving waveform Sb is _{equal to} or greater than the threshold value St. Also good.

  Subsequently, storage processing is performed in step S313, and when the correction time difference ΔT and the distance correction value Xc calculated as described above are stored in a memory or the like, the angle signal from the rotation angle sensor 52 is converted into an angle signal in step S315. Based on this, it is determined whether or not the concave mirror 41 has made one round, and the processing from step S303 is repeated with the light intensity set in step S301 until the concave mirror 41 makes one round.

  When the concave mirror 41 makes a round (Yes in S315), it is determined in step S317 whether or not the distance correction value Xc has increased. The distance correction value Xc is constant regardless of the transmittance of each of the optical fibers 91 to 94 unless the second received light waveform Sb is saturated when the influence of the ambient temperature or the like is equal. That is, since the distance correction value Xc increases when the second light reception waveform Sb is saturated, the saturation state of the second light reception waveform Sb can be determined by the increase in the distance correction value Xc.

Specifically, as shown in FIG. 13, when the second light waveform of the light receiving signal _{S 2} corresponding to each of the optical fibers 91 to 94 and _{Sb 1, Sb 2, Sb 3} , Sb 4, the transmittance is different Therefore, the light receiving sensitivity of Sb ₁ is small and the light receiving sensitivity of Sb ₄ is large. Then, Sb ₁ , Sb ₂ , and Sb ₃ that are not saturated with respect to the light guide direction distance Xf that is a true value are calculated to have the same distance correction value Xc as Xc ₁ shown in FIG. On the other hand, for Sb ₄ that is saturated because it exceeds the predetermined value Sm (see FIG. 13), the distance correction value Xc is calculated larger than other second light receiving waveforms as shown in Xc ₂ of FIG. The Rukoto.

In step S317 described above, the distance correction value Xc does not increase as compared with the other second light receiving waveforms because the second light receiving waveforms Sb ₁ , Sb ₂ , and Sb ₃ shown in FIG. 13 are not saturated. In the case (No in S317), the light intensity of the laser light L0 is increased by a predetermined amount in Step S301, and the processing from Step S303 is performed.

On the other hand, as the second light receiving waveform Sb ₄ shown in FIG. 13, the distance correction value Xc as compared to the other second light wave is increased (Yes in S317), the laser output intensity adjustment at step S319 of FIG. 12 Processing is done. In this process, the second light receiving waveforms Sb ₁ and Sb ₂ are based on the transmittance of the optical fiber through which the propagation light L4 received when the distance correction value Xc increases and the light intensity of the laser light L0. , Sb ₃ and Sb ₄ are adjusted so that the light intensity of the laser light L0 output from the laser diode 10 is saturated. The point at which the distance correction value Xc starts to increase as described above is defined as the circuit saturation start point at which the second received light waveform Sb is saturated.

  Then, in the state where the light intensity of the laser beam L0 is adjusted as described above, the laser emission process and the laser beam reception process are performed in steps S321 and S323 in the same manner as in steps S303 and S305, and the determination in step S325 is Yes. As in steps S309 to S313, correction time difference calculation processing, distance correction value calculation processing, and storage processing are performed in steps S327 to S331.

  Specifically, as shown in FIG. 14, in each saturated second light receiving waveform Sb, the distance correction value Xc is calculated so as to increase as the transmittance increases.

  Subsequently, in step S333, it is determined whether or not the concave mirror 41 has made one round as in step S315. The process from step S321 is repeated with the light intensity set in step S319 until the concave mirror 41 makes one round. It is. When the concave mirror 41 goes around (Yes in S333), it is determined in step S335 whether or not the distance correction value Xc is stored in a predetermined number memory or the like, and the distance correction value Xc is stored in the predetermined number memory or the like. If not (No in S335), the light intensity of the laser beam L0 at the current stage is increased by a predetermined amount in Step S337, and the processing from Step S321 is repeated. By such repeated processing from step S321, a large number of correction time differences ΔT and distance correction values Xc in the saturated second received light waveform Sb are stored in a memory or the like.

  When the distance correction value Xc is stored in a predetermined number of memories or the like, it is determined Yes in step S335, and correction map creation processing is performed in step S339. In this process, a correction map shown in FIG. 15 is created based on the plurality of correction time differences ΔT and distance correction values Xc stored in steps S313 and S331.

As can be seen from FIG. 15, in the range where the correction time difference ΔT is small, the distance correction value Xc is constant without saturation of the second light reception waveform Sb, so that the correction time difference ΔT and the second light reception waveform Sb are not saturated. There is little significance in obtaining the distance correction value Xc. For example, in each of the second received light waveforms shown in FIG. 13, the distance correction value Xc of Sb ₁ , Sb ₂ , Sb ₃ is equal to Xc ₁ and only the distance correction value Xc of Sb ₄ is different (marked with ○ in FIG. 15). reference).

  On the other hand, by detecting a circuit saturation start point (see FIG. 15) at which the second received light waveform Sb is saturated and acquiring a large correction time difference ΔT and distance correction value Xc in a range exceeding the circuit saturation start point, The correction accuracy by the correction map can be improved and the time for creating the correction map can be shortened. For example, in each of the second light receiving waveforms shown in FIG. 14, the distance correction value Xc is calculated so as to increase as the transmittance increases (see Δ in FIG. 15).

When the correction map is generated as described above and the correction map generation subroutine is completed, laser light emission processing is performed in step S201 of FIG. 10 and the laser light L0 having a normal light intensity is output from the laser diode 10. . Then, the laser light receiving process is performed at step S203, it acquires the received signal S ₂ output from the photodiode 20 in response to reception of the reflected light L3.

Subsequently, correction time difference calculating process at step S205 is performed, similarly to the step S309, the correction time difference ΔT in the light receiving signal S ₂ of the signal waveform corresponding to the received light of the reflected light L3 is calculated. Next, distance calculation processing is performed in step S207, and the time when the laser light L0 is output by the laser diode 10 and the time when the reflected light L3 is received by the photodiode 20 are the same as in step S111. The measurement distance X is calculated by multiplying the time difference by the speed of light or the like.

  In step S209, distance correction processing is performed. In this process, the distance correction value Xc is set based on the correction map created in step S300 from the correction time difference ΔT calculated in step S205, and the distance correction value Xc is calculated from the measurement distance X calculated in step S207. The measurement distance X is corrected by subtraction. Then, the processing from step S201 is repeated. Note that after the process in step S209, for example, the correction map creation process may be performed again in step S300 after a predetermined time has elapsed.

  As described above, in the laser radar device 1 according to the second embodiment, each correction time difference ΔT in the received light waveform of the propagation light L4 from each optical fiber 91 to 94 detected by the photodiode 20, and A relationship with the distance correction value Xc detected according to the light reception waveform of the propagation light L4 is obtained for each light reception waveform in which the light intensity of the laser light L0 is changed, and a correction map is created. Then, the measurement distance X is corrected based on the distance correction value Xc set according to the correction map from the correction time difference ΔT in the received light waveform of the reflected light L3 received by the photodiode 20.

  Thereby, even when the light reception waveform of the light reception signal output from the photodiode 20 is saturated by receiving the reflected light L3, the distance correction value Xc is set based on the correction map that takes into account the saturation state of the light reception waveform. Therefore, the detection accuracy of the distance correction value Xc is increased, and the detection accuracy of the measurement distance to the detection object can be increased.

  Further, in the laser radar device 1 according to the second embodiment, since four optical fibers 91 to 94 having different light transmittances are provided, compared with the case where only one optical fiber is provided. Thus, every time the concave mirror 41 makes one rotation, the correction time difference ΔT and the distance correction value Xc for the number of optical fibers are calculated, so the time for creating the correction map can be shortened.

  Further, in the laser radar device 1 according to the second embodiment, the range in which the distance correction value Xc increases according to the increase in the correction time difference ΔT based on the determination of Yes in step S317 (a range exceeding the circuit saturation start point). In step S319, the light intensity of the laser beam L0 is adjusted, so that the light reception waveform is not saturated. Since the number of times of calculating ΔT and the distance correction value Xc is reduced, the time for creating the correction map by reducing the number of times of calculation of the correction time difference ΔT and the distance correction value Xc that are unnecessary for creating the correction map. Can be shortened.

The present invention is not limited to the above embodiments, and may be embodied as follows. Even in this case, the same operations and effects as those of the above embodiments can be obtained.
(1) In the said 1st Embodiment, it may replace with the optical fiber 74 and may employ | adopt light guide members, such as a cable which can guide light. In addition, the optical fiber 74 is not limited to be disposed in a spiral shape, and may be disposed in the case 3 by reducing the space occupied in the case 3 by, for example, bending a plurality of places. The same applies to the second embodiment.

(2) In the second embodiment, when the distance correction value Xc is stored in a predetermined number of memories or the like in step S335, the correction map is not limited to creating a correction map. The correction map may be created by determining Yes in step S335 after a predetermined time has elapsed from the start of the creation processing subroutine.

(3) In the second embodiment, the light reception sensitivity of the light reception waveform received by the photodiode 20 is not changed by adjusting the light intensity of the laser light L0 output from the laser diode 10, but for example, The light receiving sensitivity of the light receiving waveform may be changed by adjusting the sensitivity of the photodiode 20.

(4) In the second embodiment, the case 3 is not limited to providing four optical fibers, and two or three optical fibers may be provided, or five or more optical fibers may be provided.

(5) In step S317 of the second embodiment, the distance correction value Xc changes in consideration of the reference position with respect to the second light reception waveform Sb, without being limited to determining whether or not the distance correction value Xc has increased. It may be determined whether or not (or a sudden change) has occurred.

DESCRIPTION OF SYMBOLS 1 ... Laser radar apparatus 3 ... Case 10 ... Laser diode (laser light generation means)
20 ... Photodiode (light detection means)
40... Turning deflection mechanism (turning deflection means)
41. Concave mirror (deflection means)
50. Motor (driving means)
52 ... Rotation angle sensor 70, 70a ... Condenser 73 ... Cover (first cover)
73a, 76a ... inner peripheral surface 74, 91-94 ... optical fiber (light guide member)
74a ... one end 74b ... the other end 75 ... light introduction part 75a ... half mirror 76 ... cover (second cover)
80... Control circuit (distance measuring means, correction value calculating means, distance correcting means, map creating means)
L0 ... laser light L3 ... reflected light L4 ... propagating light S 1 _... emission signal S 2 _... light receiving signal Sb ... second receiver frequency X ... measuring distance Xc ... distance correction value Xf ... light guiding direction distance T ... light time [Delta] T ... Correction time difference

Claims (11)

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;
A deflection unit configured to be rotatable about a predetermined central axis is provided. The laser beam is deflected toward the space by the deflection unit, and the reflected light is deflected toward the light detection unit. Dynamic deflection means;
Drive means for driving the rotation deflection means;
The distance to the detection object is measured based on the 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. Distance measuring means;
A laser radar device comprising:
A light guide member that guides a part of the laser light from the laser light generation means and emits the light to the light detection means;
From the generation of the laser light by the laser light generation means until a part of the laser light is guided by the light guide member and detected by the light detection means, and the light guide direction of the light guide member Correction value calculating means for calculating a distance correction value according to the distance;
Distance correcting means for correcting the distance to the detected object detected by the distance measuring means based on the distance correction value calculated by the correction value calculating means;
A laser radar device comprising:   The laser radar device according to claim 1, wherein the light guide member is an optical fiber.   The laser radar device according to claim 1, wherein the light guide member is disposed in a spiral shape.   In the light guide member, a part of the laser beam deflected by the deflecting unit is guided into the light guide member at one end portion in the light guide direction and the light is detected from the other end portion in the light guide direction. The laser radar device according to any one of claims 1 to 3, wherein the laser radar device is configured to emit light toward the means.   In the light guide member, a part of the laser beam deflected by the deflecting unit is guided into the light guide member at one end portion in the light guide direction and from the other end portion in the light guide direction. The laser radar device according to claim 1, wherein the laser radar device is configured to be emitted toward the light source and deflected toward the light detection unit by the deflection unit.   In the light guide member, a part of the laser beam deflected by the deflecting unit is guided into the light guide member at one end portion in the light guide direction and is provided at the other end portion in the light guide direction. So that the light is reflected in the light guide member in the reverse direction, emitted from one end of the light guide direction toward the deflecting means, and deflected toward the light detecting means by the deflecting means. The laser radar device according to claim 1, wherein the laser radar device is configured as follows. On the light receiving side of the light detection means, a first cover whose inner diameter is tapered toward the light detection means is provided,
5. The laser radar device according to claim 1, wherein the light guide member emits a part of the laser light toward an inner peripheral surface of the first cover. 6. On the light receiving side of the light detection means, a second cover whose inner diameter is reduced stepwise toward the light detection means is provided.
5. The laser radar device according to claim 1, wherein the light guide member emits part of the laser light toward an inner peripheral surface of the second cover. 6. When the light reception waveform of the light emitted from the light guide member detected by the light detection means is equal to or greater than a predetermined threshold for detecting the light reception state and when the light reception waveform is equal to or less than the predetermined threshold The relationship between the time difference between the time and the distance correction value calculated according to the light guide time detected according to the light reception waveform and the distance in the light guide direction is a light reception waveform in which the light reception sensitivity is changed. A map creation means for creating a correction map is obtained for each,
The distance correction means sets the distance to the detection object detected by the distance measurement means according to the correction map from the time difference in the light reception waveform of the reflected light received by the light detection means. The laser radar device according to claim 1, wherein correction is performed based on the distance correction value. A plurality of the light guide members having different light transmittances,
The map creating means determines the relationship between the time difference and the distance correction value in the light reception waveform of the light emitted from each light guide member detected by the light detection means for each light reception waveform whose light reception sensitivity is changed. The laser radar device according to claim 9, wherein the correction map is created by obtaining the correction map.   11. The laser radar according to claim 9, wherein the map creating unit changes a light receiving sensitivity of the light receiving waveform in accordance with a range in which the distance correction value changes in accordance with a change in the time difference. apparatus.

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