Distance measurement device

Abstract

To provide a distance measurement device which has high resistance to contamination in a path of light or an electromagnetic wave for distance measurement and capable of maintaining distance measurement accuracy even when obstacles exist in the path of the light or the electromagnetic wave for distance measurement.SOLUTION: A distance measurement device includes: a light emission unit that emits outgoing light; a light reception unit that receives reflected light being the outgoing light reflected by a measurement target; a housing that stores the light emission unit and the light reception unit, forms an opening provided on an optical path of the outgoing light, and has an opening end part that is formed along an inner surface of a light-transmissive member of a movable body and has a shape along the inner surface of the light-transmissive member; and a deflection plate that covers the opening at the opening end part and includes a deflection section that deflects the outgoing light. The light emission unit emits first outgoing light in a first direction and second outgoing light in a second direction. The deflection section includes a first deflection section that deflects the first outgoing light. A first irradiation area which is irradiated with the first outgoing light deflected by the first deflection section and a second irradiation area which is irradiated with the second outgoing light at least partially overlap with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a distance measuring device. [Background technology]

[0002] Distance measuring devices that use light or electromagnetic waves to measure the distance to an object have been used in the past. For example, Patent Document 1 discloses a radar device that uses a dielectric lens to switch the emission direction of a radar beam to perform detection in a plurality of different areas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-145399 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in the case of a distance measuring device that uses light or electromagnetic waves to measure the distance to an object, a light-transmitting material such as a light-transmitting resin is provided in the area through which the light or electromagnetic waves for distance measuring pass in order to protect the device. If such a part through which the light or electromagnetic waves pass becomes dirty, the accuracy of distance measurement may decrease or distance measurement may become difficult.

[0005] In addition, if a distance measuring device is installed inside a moving body such as an automobile and distance measuring of the outside world is performed, for example, through the windshield, the distance measuring accuracy may decrease or distance measuring may become difficult when the wipers are operating.

[0006] The present invention has been made in view of the above-mentioned points, and has an object to provide a distance measuring device that is highly resistant to contamination on the path of light or electromagnetic waves used for distance measurement, and that can maintain distance measurement accuracy even when an obstacle is present on the path of light or electromagnetic waves used for distance measurement. [Means for solving the problem]

[0007] The invention described in claim 1 is a distance measuring device comprising: a light emitting unit that emits emitted light; a light receiving unit that receives reflected light, which is the emitted light reflected by an object to be measured; a housing that houses the light emitting unit and the light receiving unit, forms an opening on the optical path of the emitted light, and has an opening end that is formed along an inner surface of a light-transmitting member of a moving body and has a shape that follows the inner surface of the light-transmitting member; and a deflection plate that covers the opening at the opening end and has a deflection unit that deflects the emitted light, wherein the light emitting unit emits a first emitted light in a first direction and emits a second emitted light in a second direction, the deflection unit has a first deflection unit that deflects the first emitted light, and a first illumination area onto which the first emitted light deflected by the first deflection unit and a second illumination area onto which the second emitted light is irradiated at least partially overlap each other. [Brief description of the drawings]

[0008] [Figure 1] 1 is a top view of an automobile equipped with a distance measuring device according to a first embodiment. [Diagram 2] 1 is a cross-sectional view of a distance measuring device according to a first embodiment. [Diagram 3] 1 is a side view of an automobile equipped with a distance measuring device according to a first embodiment. [Figure 4] FIG. 2 is a functional block diagram of a controller of the distance measuring device according to the first embodiment. [Diagram 5] FIG. 4 is a diagram showing an operation control routine of the distance measuring device according to the first embodiment. [Figure 6] FIG. 11 is a cross-sectional view of a distance measuring device according to a modified example. [Figure 7] FIG. 11 is a top view of an automobile equipped with a distance measuring device according to a second embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a distance measuring device according to a second embodiment. [Figure 9] FIG. 11 is a side view of an automobile equipped with a distance measuring device according to a second embodiment. [Figure 10] FIG. 11 is a functional block diagram of a controller of a distance measuring device according to a second embodiment. [Figure 11] FIG. 11 is a diagram showing an operation control routine of the distance measuring device according to the second embodiment. [Figure 12] FIG. 11 is a cross-sectional view of a distance measuring device according to a modified example. [Figure 13] FIG. 13 is a top view of an automobile equipped with a distance measuring device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a distance measuring device is mounted on an automobile as an example of a moving object. EXAMPLES

[0010] [Configuration of distance measuring device] 1 is a top view of an automobile M equipped with a distance measuring device 10 according to the first embodiment. In the first embodiment, a case will be described in which the distance measuring device 10 is attached to the front bumper of the automobile M. In the following description, the front-rear direction of the automobile M is defined as the X direction, the left-right direction, i.e., the width direction, as the Y direction, and the up-down direction as the Z direction.

[0011] The distance measuring device 10 is a laser distance measuring device that measures distance by emitting a laser beam and receiving light reflected by an object. The distance measuring device 10 is mounted in the center of the front end of the automobile M. In other words, the distance measuring device 10 is attached so as to overlap with a center line AX along the front-rear direction of the automobile M when viewed from the top-down direction. The distance measuring device 10 is configured to be able to emit a laser beam toward an irradiation area LR in front of the automobile M. FIG. 1 shows, as an example, a case where the irradiation area LR is an area that is line-symmetrical with respect to the center line AX when viewed from above the automobile M.

[0012] Fig. 2 is a cross-sectional view of the distance measuring device 10 taken along a plane including the central axis AX and the Z axis in Fig. 1. The housing 11 has a rectangular cylindrical tube portion 11A that extends in the front-rear direction of the automobile M, i.e., has a tube axis along the X axis, and a rectangular bottom portion 11B that closes one of the openings of the tube portion 11A. In other words, the housing 11 is a box in which an opening portion 11C is formed.

[0013] A laser emitting / receiving device 13 is provided in the center of the inner surface 11S of the bottom 11B of the housing 11 as a light emitting unit capable of emitting a pulsed laser in a variable direction toward the opening 11C. The laser emitting / receiving device 13 has, for example, a laser element (not shown) that emits laser light and a MEMS mirror (not shown) that reflects the laser light in a variable direction. In addition, the laser emitting / receiving device 13 as a light receiving unit has a light receiving element (not shown) that can receive and detect reflected light of the emitted laser light reflected by an object. For example, the laser emitting / receiving device 13 is a so-called laser LiDER device.

[0014] The laser emitting and receiving device 13 can emit a first emitted light EL1 to a first emitting region ER1 in a first directional range as seen from the laser emitting and receiving device 13. The laser emitting and receiving device 13 can also emit a second emitted light EL2 to a second emitting region ER2 in a second directional range as seen from the laser emitting and receiving device 13. In other words, the laser emitting and receiving device 13 can emit the first emitted light EL1 in a first direction in the first directional range, and can emit the second emitted light EL2 in a second direction in the second directional range. The laser emitting and receiving device 13 can scan a pulsed laser toward the first emitting region ER1 and the second emitting region ER2.

[0015] The scanning mode of the pulsed laser may be, for example, raster scanning or Lissajous scanning. That is, the entire first emission region ER1 and the entire second emission region ER2 may be sequentially scanned by raster scanning. Also, the entire first emission region ER1 and the entire second emission region ER2 may be scanned at once by Lissajous scanning.

[0016] The protective plate 15 is a light-transmitting member such as a plate-shaped resin or glass material provided to cover the opening 11C. The light-transmitting member used for the protective plate 15 is a member that transmits light having the wavelengths of the emitted light EL1 and EL2 emitted by the laser emission and reception device 13.

[0017] The light emitted from the laser emission and reception device 13 passes through the protective plate 15 and goes out from the distance measuring device 10 to the outside. The reflected light received by the laser emission and reception device 13 passes through the protective plate 15 and reaches the laser emission and reception device 13 from the outside. The protective plate 15 has a function of preventing foreign matter from entering the distance measuring device 10 while transmitting the light emitted from the laser emission and reception device 13 and the light reflected to the laser emission and reception device 13. A removal device for removing foreign matter attached to the surface 15S of the protective plate 15 may be provided. For example, a wiper device (not shown) operable along the surface 15S of the protective plate 15 may be provided.

[0018] In Example 1, the protective plate 15 is described as being flat, but the protective plate 15 may be dome-shaped, for example, having a convex shape facing the outside of the housing 11, i.e., a convex shape facing the emission direction of the emitted light EL1 and EL2 from the laser emission / reception device 13.

[0019] The deflection plate 17 is a light-transmitting member made of a plate-shaped resin or glass material provided between the protective plate 15 and the laser emission / reception device 13 inside the housing 11. The light-transmitting member used for the deflection plate is a member that transmits light of the wavelengths of the emitted light EL1 and EL2 emitted by the laser emission / reception device 13. That is, the light emitted from the laser emission / reception device 13 passes through the deflection plate 17 and the protective plate 15 in this order and exits from the distance measuring device 10 to the outside. The reflected light received by the laser emission / reception device 13 passes through the protective plate 15 and the deflection plate 17 in this order and reaches the laser emission / reception device 13 from the outside.

[0020] A first deflection section 17A is formed in a portion of the deflection plate 17 through which the first outgoing light EL1 passes. The first deflection section 17A is a portion that has the function of a transmissive deflection element that transmits the first outgoing light EL1 and deflects it downward. The first deflection section 17A may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0021] A second deflection section 17B is formed in a portion of the deflection plate 17 through which the second output light EL2 passes. The second deflection section 17B is a portion that has the function of a transmissive deflection element that transmits the second output light EL2 while deflecting it upward. The second deflection section 17B may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0022] The first outgoing light EL1 is deflected downward when passing through the first deflection unit 17A, and becomes the first irradiation light LL1 that is irradiated to the first irradiation region LR1. In other words, the first irradiation region LR1 is an area that is irradiated with the first outgoing light EL1 deflected by the first deflection unit 17A.

[0023] The second output light EL2 is deflected downward when passing through the second deflection unit 17B, and becomes the second irradiation light LL2 that is irradiated to the second irradiation region LR2. In other words, the second irradiation region LR2 is an area that is irradiated with the second output light EL2 deflected by the second deflection unit 17B.

[0024] As described above, the first deflection portion 17A and the second deflection portion 17B are each formed in a predetermined region of the deflection plate 17. In other words, the first deflection portion 17A and the second deflection portion 17B are held by the deflection plate 17, and the deflection plate 17 serves as a holding member for the first deflection portion 17A and the second deflection portion 17B.

[0025] The first deflection section 17A and the second deflection section 17B do not have to be built into the deflection plate 17. In other words, the first deflection section 17A and the second deflection section 17B may be formed separately from the deflection plate 17, and the deflection plate 17 may hold the first deflection section 17A and the second deflection section 17B which are separate from each other.

[0026] 2, holes may be formed in the deflection plate 17 at the positions where the first deflection unit 17A and the second deflection unit 17B are present, and members forming the deflection units 17A and 17B may be fitted into the holes so that the deflection plate 17 holds them. Also, the members forming the deflection units 17A and 17B may be fixed to the surface of the deflection plate 17 by adhesion or the like, so that the deflection plate 17 holds the deflection units 17A and 17B.

[0027] In addition, the portions of the deflection plate 17 other than the first deflection portion 17A and the second deflection portion 17B may not be transparent because the emitted light beams EL1 and EL2 do not reach them. In addition, the first deflection portion 17A and the second deflection portion 17B may not be formed in the deflection plate 17, but may be held on the optical path of the first emitted light beam and the optical path of the second emitted light beam, respectively. Therefore, the first deflection portion 17A and the second deflection portion 17B may be formed of separate members, and may be held by another holding member fixed to the housing 11, instead of being held by the deflection plate 17.

[0028] 2, the center line CX1 of the first irradiation area LR1 and the center line CX2 of the second irradiation area LR2 are parallel to each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are a group of light rays that are irradiated in the same direction.

[0029] Moreover, the first irradiation light LL1 and the second irradiation light LL2 are irradiated to the outside through different parts of the protective plate 15. That is, when passing through the protective plate 15, the first irradiation light LL1 and the second irradiation light LL2 pass through different paths.

[0030] Fig. 3 is a side view of an automobile M equipped with a distance measuring device 10. Fig. 3 shows an enlarged view of the front end portion of the automobile M. In Fig. 3, the first irradiation light LL1 is shown by a two-dot chain line, and the second irradiation light LL2 is shown by a dashed line.

[0031] As shown in Fig. 3, the first irradiation light LL1 and the second irradiation light LL2 are irradiated to areas that are slightly shifted but substantially overlap each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are irradiated to substantially the same area. In other words, the first irradiation area LR1 and the second irradiation area LR2 at least partially overlap each other.

[0032] As described above with reference to Fig. 2, the irradiated light beams LL1 and LL2 are emitted from the aperture 11C (see Fig. 2) of the distance measuring device via different paths through different parts of the protective plate 15, but from a macroscopic perspective, they are irradiated onto substantially the same area, although there is a slight shift. In other words, the emitted light beams EL1 and EL2 emitted in two different directional ranges become the irradiated light beams LL1 and LL2 that are irradiated onto substantially the same area.

[0033] The distance measuring device 10 has a configuration in which the irradiated lights LL1 and LL2 exit the distance measuring device 10 via different paths, specifically by passing through different parts of the protective plate 15, while being irradiated onto substantially the same area outside the distance measuring device 10. In other words, the distance measuring device 10 has a redundant configuration in which a single laser emitting / receiving device 13 generates multiple irradiated lights that are irradiated onto the same area, and the distance measuring device 10 is capable of measuring the distance to the same area using these multiple irradiated lights.

[0034] Therefore, even if the protective plate 15 of the distance measuring device 10 is partially soiled, accurate distance measurement is possible. Specifically, even if the portion through which one of the irradiated lights LL1 and LL2 passes is soiled, accurate distance measurement is possible by using the other irradiated light.

[0035] [Controller configuration] 4 is a diagram showing the configuration of a controller 20 that controls the light emission of the laser emission and reception device 13 of the distance measuring device 10 and is responsible for the distance measuring function. The controller 20 may be provided, for example, separately from the laser emission and reception device 13 and connected to the laser emission and reception device 13 so as to be able to communicate with it. The controller 20 may also be provided, for example, within the laser emission and reception device 13. In the following description, an example will be described in which the controller 20 is provided separately from the laser emission and reception device 13.

[0036] The controller 20 is a device in which a large-capacity storage device 23, a control unit 25, and an input / output unit 27 cooperate with each other via a system bus 21, for example.

[0037] The large-capacity storage device 23 is configured, for example, with a hard disk device, a solid state drive (SSD), a flash memory, etc., and stores various programs such as an operating system and software for terminals. Note that the various programs may be obtained, for example, from other server devices, etc., via a network, or may be recorded on a recording medium and read via various drive devices.

[0038] In other words, the various programs stored in the large-capacity storage device 23 (including programs for executing processes for controlling the laser emission / reception device 13 and for ranging, as described below) can be transmitted via a network, and can also be recorded on a computer-readable recording medium and transferred.

[0039] The control unit 25 is configured with a CPU (Central Processing Unit) 25A, a ROM (Read Only Memory) 25B, a RAM (Random Access Memory) 25C, etc., and functions as a computer. The CPU 25A reads out and executes various programs stored in the ROM 25B and the large-capacity storage device 23 to realize various functions.

[0040] The input / output unit 27 is a functional part that communicates information with the laser emitting / receiving device 13. The input / output unit 27 can transmit a control signal for controlling the operation of the laser emitting / receiving device 13 to the laser emitting / receiving device 13. The input / output unit 27 can also receive from the laser emitting / receiving device 13 a light receiving signal that is a signal received when the laser emitting / receiving device 13 receives reflected light.

[0041] Based on the received signals, the control unit 25 can calculate the distance between the object that reflected the irradiated lights LL1 and LL2 and the distance measuring device 10 or the automobile M. For example, the control unit 25 can calculate the distance using a Time Of Flight (TOF) method or a phase difference method.

[0042] The input / output unit 27 may be capable of communicating with other devices. For example, the input / output unit 27 may be capable of receiving information on whether a distance measurement operation is currently required from an external device. The control unit 25 may generate a control signal for controlling the laser emitting / receiving device 13 in response to the information on whether a distance measurement operation is required, and transmit the control signal to the laser emitting / receiving device 13 via the input / output unit 27.

[0043] For example, the distance measuring device 10 may be provided with a removal device such as a wiper capable of removing foreign matter adhering to the surface 15S of the protective plate 15. That is, the distance measuring device 10 may be provided with a removal means for removing obstacles on the optical paths of the first irradiation light and the second irradiation light. In this case, the input / output unit 27 may be capable of communicating information with the removal device.

[0044] For example, when the control unit 25 detects the presence of a foreign object on the surface 15S of the protective plate 15, it may be capable of generating a control signal that causes the removal device to perform the operation of removing the foreign object, and transmitting the control signal to the removal device via the input / output unit 27.

[0045] The detection of a foreign object on the surface 15S of the protective plate 15 may be performed based on a light receiving signal, which is a signal received when the reflected light is received by the laser emitting / receiving device 13. For example, when distance measurement processing is performed based on the light receiving signal, if an object is detected at a distance equal to or greater than a threshold, it may be determined that a foreign object is present on the surface 15S of the protective plate 15.

[0046] [Distance measurement control routine] A distance measurement operation control routine executed by the control unit 25 in order to realize the redundant distance measurement operation of the distance measuring device 10 of the first embodiment will be described below.

[0047] 5 is a flow diagram of an operation control routine R1, which is an example of a distance measurement operation control routine. For example, the operation control routine R1 is started when power is supplied to the distance measuring device 10, and is executed repeatedly. The operation control routine R1 may be started when the ACC power of the automobile in which the distance measuring device 10 is mounted is turned on.

[0048] In the operation control routine R1, distance measurement is normally performed using both the irradiated light beams LL1 and LL2. If a foreign object adheres to the surface 15S of the protective plate 15 during distance measurement using both the irradiated light beams LL1 and LL2, distance measurement using the irradiated light beams that pass through the area where the foreign object adheres is stopped. In other words, distance measurement is continued using only the irradiated light beams that do not have a foreign object on their path.

[0049] When the operation control routine R1 is started, the control unit 25 first determines in step S11 whether or not a distance measurement operation is required in the automobile M. This determination may be made, for example, based on whether or not the automobile M is in an automatic driving state. Specifically, information on whether the automobile M is currently under automatic driving control or manual driving control may be obtained, and if the automobile M is under automatic driving control, it may be determined that a distance measurement operation is required.

[0050] In addition, the determination as to whether or not a distance measurement operation is required may be made by determining whether or not a distance measurement start operation has been performed by a passenger in the automobile M. In addition, the determination as to whether or not a distance measurement operation is required may be made based on the traveling speed of the automobile M or the current traveling position of the automobile M.

[0051] In step S11, if it is determined that the distance measurement operation is not required (step S11: NO), the operation control routine R1 is executed again from the beginning. In step S11, if it is determined that the distance measurement operation is required (step S11: YES), the control unit 25 starts distance measurement in a normal scanning mode in which the laser emitting / receiving device 13 emits the emitted light beams EL1 and EL2 to perform scanning (step S12). In this normal scanning mode, raster scanning may be performed to alternately scan the irradiation areas LR1 and LR2 with the emitted light beams LL1 and LL2. That is, the control unit 25 causes the laser emitting / receiving device 13 as a light emitting unit to emit the first emitted light beam EL and the second emitted light beam EL2.

[0052] After executing step S12, the control unit 25 judges in step S13 again whether or not a distance measurement operation is required in the automobile M. This judgment can be made in the same manner as the judgment in step S111 described above. If it is judged in step S13 that a distance measurement operation is not required (step S13: NO), the control unit 25 causes the laser emission / reception device 13 to stop emitting the emitted lights EL1 and EL2, and the distance measurement operation ends (step S14). After the end of step S14, the operation control routine R1 is executed again from the beginning.

[0053] When it is determined in step S13 that the distance measurement operation is still required (step S13: YES), the control unit 25 determines whether or not a foreign object is present on the surface 15S of the protection plate 15 on the path of the irradiated light LL1 and LL2 (step S15). This determination can be made by detecting the foreign object based on the light receiving signal from the laser emitting / receiving device 13. Specifically, for example, in distance measurement using either the irradiated light LL1 or LL2, it may be determined that a foreign object is present on the surface 15S of the protection plate 15 when an object is detected at a distance closer than a predetermined threshold.

[0054] If it is determined in step S15 that no foreign object is present (step S15: NO), the control unit 25 executes step S13 again to determine whether the distance measurement operation is still required.

[0055] In step S15, if it is determined that a foreign object is present (step S15: YES), the control unit 25 stops distance measurement using the irradiation light LL1 and LL2 whose path includes the area where the foreign object is present, and transitions to a single scan mode, which is a mode in which distance measurement is performed only using irradiation light that does not have a foreign object present on its path (step S16).

[0056] In the single scanning mode, only either the emitted light EL1 or EL2 may be emitted to the laser emitting / receiving device 13. In other words, only the emitted light to be used for distance measurement among the irradiation lights LL1 and LL2 may be emitted to the laser emitting / receiving device 13. In addition, in the single scanning mode, both the emitted lights EL1 and EL2 may be emitted to the laser emitting / receiving device 13, and only the reflected light of either the irradiation lights LL1 or LL2 may be used for distance measurement.

[0057] After step S16 is executed, the control unit 25 judges in step S17 whether or not a distance measurement operation is required again in the automobile M. This judgment can be performed in the same manner as the judgment in step S11 described above. If it is judged in step S17 that a distance measurement operation is not required (step S17: NO), the control unit 25 causes the laser emission / reception device 13 to stop emitting the emitted light beams EL1 and EL2, and the distance measurement operation ends (step S14). After step S14 ends, the operation control routine R1 is executed again from the beginning.

[0058] If it is determined in step S17 that the distance measurement operation is still required (step S17: YES), the control unit 25 determines whether or not the foreign object detected in the above step S15 remains (step S18). This determination can be made by detecting the foreign object based on the light reception signal from the laser emission / reception device 13. Specifically, for example, when distance measurement is attempted using irradiation light that is not used in the single scanning mode and an object is detected at a distance closer than a predetermined threshold, it may be determined that a foreign object remains on the surface 15S of the protective plate 15.

[0059] In step S18, if it is determined that a foreign substance remains (step S18: YES), the control unit 25 executes step S17 again, that is, the distance measurement in the single scan mode is continued.

[0060] In step S18, if it is determined that no foreign matter remains (step S18: NO), the control unit 25 returns to the normal scanning mode in which distance measurement is performed using both the irradiation lights LL1 and LL2, and continues distance measurement (step S19).

[0061] In addition, if the distance measuring device 10 is equipped with a removal device, such as a wiper, capable of removing foreign matter adhering to the surface 15S of the protective plate 15, a removal operation to remove the foreign matter may be performed during distance measuring in single scan mode.

[0062] As described above, the distance measuring device 10 has a configuration in which the illumination lights LL1 and LL2 generated by the emission lights EL1 and EL2 from one laser emission / reception device 13 exit the distance measuring device 10 via different paths, specifically, by passing through different parts of the protective plate 15, and are illuminated onto approximately the same area outside the distance measuring device 10. In other words, the distance measuring device 10 has a redundant configuration that allows the same area to be measured with the illumination lights LL1 and LL2.

[0063] In the distance measuring device 10 having the above configuration, when the operation control routine R1 is executed, accurate distance measurement can be continued even if the protective plate 15 of the distance measuring device 10 is partially soiled. Specifically, even if the portion through which one of the irradiated lights LL1 and LL2 passes is soiled, accurate distance measurement can be continued by measuring the distance using the other irradiated light.

[0064] In the above description, the deflection plate 17 is formed with two deflection portions, 17A and 17B, but the deflection portion may be one. For example, as shown in Fig. 6, only the deflection portion 17A may be formed and only ER1 may be deflected. In this case, if the output light EL1 is deflected so that the center lines CX1 and CX2 of the illumination lights LL1 and LL2 that have passed through the deflection plate 17 are parallel to each other, the illumination lights LL1 and LL2 will be irradiated onto substantially the same area, as in the distance measuring device described above. EXAMPLES

[0065] Second Embodiment A distance measuring device 30 according to a second embodiment of the present invention will now be described.

[0066] [Configuration of distance measuring device] 7 is a top view of an automobile M equipped with a distance measuring device 30 according to Example 2. In Example 2, a case will be described in which the distance measuring device 30 is attached to the inside of the windshield FG of the automobile M. In the following description, the front-rear direction of the automobile M is defined as the X direction, the left-right direction, i.e., the width direction, as the Y direction, and the up-down direction as the Z direction.

[0067] Similar to the distance measuring device 10 of the first embodiment, the distance measuring device 30 is a laser distance measuring device that emits a laser beam and receives the reflected light of the emitted laser beam reflected by an object to measure distance. The distance measuring device 30 is mounted in the center part of the inside of the windshield FG of the automobile M. In other words, the distance measuring device 30 is attached so as to overlap with the center line AX along the front-rear direction of the automobile M when viewed from the top-bottom direction.

[0068] The distance measuring device 30 is configured to be able to emit laser light toward an irradiation area LR in front of the automobile M. In Fig. 7, as an example, the irradiation area LR is shown as an area that is line-symmetrical with respect to the center line AX when viewed from above the automobile M.

[0069] Fig. 8 is a cross-sectional view of the distance measuring device 30 taken along a plane including the central axis AX and the Z axis in Fig. 7. The automobile M is provided with a wiper device WP capable of removing foreign matter on the outer surface OS of the windshield FG.

[0070] The housing 31 has a rectangular cylindrical tube portion 31A that extends in the vertical direction of the automobile M, i.e., has a cylindrical axis in the direction along the Z axis, and a rectangular bottom portion 31B that closes one of the openings of the tube portion 11A. In other words, the housing 31 is a box body in which an opening 31C is formed.

[0071] Opening edge 31E as an opening edge forming opening 31C of housing 31 has a shape that conforms to inner surface IS of windshield FG. That is, opening edge 31E has a shape that slopes downward toward the front of automobile M. In the embodiment, opening edge 31E is covered by windshield FG.

[0072] A laser emitting / receiving device 33 capable of emitting a pulsed laser in a variable direction toward the opening 31C is provided in the center of the inner surface S31 of the bottom 31B of the housing 31. The laser emitting / receiving device 33 is a device similar to the laser emitting / receiving device 13 of the first embodiment, and has, for example, a laser element that emits a laser beam and a MEMS mirror that reflects the laser beam in a variable direction. In addition, the laser emitting / receiving device 33 as a light receiving unit has a light receiving element that can receive and detect reflected light of the emitted laser beam reflected by an object. For example, the laser emitting / receiving device 33 is a so-called laser LiDER device.

[0073] The laser emitting and receiving device 33 can emit a first emitted light EL1 to a first emitting region ER1 in a first directional range as seen from the laser emitting and receiving device 33. The laser emitting and receiving device 33 can also emit a second emitted light EL2 to a second emitting region ER2 in a second directional range as seen from the laser emitting and receiving device 33. The laser emitting and receiving device 33 can scan a pulsed laser toward the first emitting region ER1 and the second emitting region ER2.

[0074] The scanning mode of the pulsed laser may be, for example, raster scanning or Lissajous scanning. That is, the entire first emission region ER1 and the entire second emission region ER2 may be sequentially scanned by raster scanning. Also, the entire first emission region ER1 and the entire second emission region ER2 may be scanned together by Lissajous scanning.

[0075] The deflection plate 35 is a light-transmitting member made of a plate-shaped resin or glass material provided at the open end 31E of the housing 31. The light-transmitting member used for the deflection plate is a member that transmits the emitted light beams EL1 and EL2 emitted by the laser emission and reception device 33. That is, the light emitted from the laser emission and reception device 33 passes through the deflection plate 35 and goes out from the distance measuring device 30 to the outside. Also, the reflected light received by the laser emission and reception device 33 passes through the deflection plate 35 and reaches the laser emission and reception device 33 from the outside.

[0076] A first deflection section 35A is formed in a portion of the deflection plate 35 through which the first outgoing light EL1 passes. The first deflection section 35A is a portion that has the function of a transmissive deflection element that transmits the first outgoing light EL1 and deflects it forward. The first deflection section 35A may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0077] A second deflection section 35B is formed in a portion of the deflection plate 35 through which the second output light EL2 passes. The second deflection section 35B is a portion that has the function of a transmissive deflection element that transmits the second output light EL2 while deflecting it forward. The second deflection section 35B may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0078] The first output light EL1 is deflected forward when passing through the first deflection unit 35A, and becomes the first irradiation light LL1 that is irradiated to the first irradiation region LR1. The second output light EL2 is deflected forward when passing through the second deflection unit 35B, and becomes the second irradiation light LL2 that is irradiated to the second irradiation region LR2.

[0079] 8, the center line CX1 of the first irradiation area LR1 and the center line CX2 of the second irradiation area LR2 are parallel to each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are a group of light rays that are irradiated in the same direction.

[0080] Moreover, the first irradiation light LL1 and the second irradiation light LL2 are irradiated to the outside through different parts of the windshield FG, that is, the first irradiation light LL1 and the second irradiation light LL2 pass through different paths when passing through the windshield FG.

[0081] Fig. 9 is a side view of an automobile M equipped with a distance measuring device 30. Fig. 9 shows an enlarged view of the front part including the windshield FG of the automobile M. In Fig. 9, the first irradiation light LL1 is shown by a two-dot chain line, and the second irradiation light LL2 is shown by a dashed line.

[0082] 9, the first irradiation light LL1 and the second irradiation light LL2 are irradiated onto regions that are slightly offset but substantially overlap each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are irradiated onto substantially the same region.

[0083] As described above with reference to Fig. 8, the illuminating lights LL1 and LL2 are emitted from the aperture 11C (see Fig. 2) of the distance measuring device through different parts of the windshield FG via different paths, but from a macroscopic perspective, they are irradiated onto almost the same area, although there is a slight shift between them. In other words, the emitted lights EL1 and EL2 emitted in two different directional ranges become the illuminating lights LL1 and LL2 that are irradiated onto almost the same area.

[0084] The distance measuring device 30 has a configuration in which the irradiated lights LL1 and LL2 exit the distance measuring device 30 via different paths, specifically, by passing through different parts of the windshield FG, and are irradiated onto substantially the same area outside the distance measuring device 30. In other words, the distance measuring device 30 has a redundant configuration that can measure the distance to the same area with the irradiated lights LL1 and LL2. Therefore, even if the windshield FG of the distance measuring device 30 is partially soiled, accurate distance measurement is possible. Specifically, even if the part through which one of the irradiated lights LL1 or LL2 passes is soiled, accurate distance measurement is possible by measuring the distance using the other irradiated light.

[0085] The distance measuring device 30 has an opening end 31E shaped to fit the inner surface IS of the windshield FG. This allows the distance measuring device to be installed compactly, for example, on the dashboard and in close contact with or very close to the windshield FG. The distance measuring device may be installed partially or completely buried in the dashboard, i.e., embedded in the dashboard.

[0086] The opening end 31E of the distance measuring device 30 may be in close contact with the inner surface IS of the windshield FG. The opening end 31E of the distance measuring device 30 may be spaced apart from the inner surface IS of the windshield FG. When the opening end 31E and the inner surface IS of the windshield FG are spaced apart, a sealant may be filled in the space.

[0087] [Controller configuration] 10 is a diagram showing the configuration of a controller 40 that controls the light emission of the laser emission and reception device 33 of the distance measuring device 30 and is responsible for the distance measuring function. The controller 40 may be provided, for example, separately from the laser emission and reception device 33 and connected to the laser emission and reception device 33 so as to be able to communicate with it. The controller 40 may also be provided, for example, within the laser emission and reception device 33. In the following description, an example will be described in which the controller 40 is provided separately from the laser emission and reception device 33.

[0088] The controller 40 may be communicably connected to a wiper driving unit WPA that drives the wiper WP. Specifically, the wiper device may be driven by a signal from the controller 40. The controller 40 may be capable of detecting whether the wiper device is operating.

[0089] The controller 40 is a device in which a large-capacity storage device 43, a control unit 45, and an input / output unit 47 cooperate with each other via a system bus 41, for example.

[0090] The large-capacity storage device 43 is configured, for example, with a hard disk device, a solid state drive (SSD), a flash memory, etc., and stores various programs such as an operating system and software for terminals. Note that the various programs may be obtained, for example, from other server devices, etc., via a network, or may be recorded on a recording medium and read via various drive devices.

[0091] In other words, the various programs stored in the large-capacity storage device 43 (including programs for controlling the laser emission / reception device 33 and executing processing for distance measurement, as described below) can be transmitted via a network, and can also be recorded on a computer-readable recording medium and transferred.

[0092] The control unit 45 is configured with a CPU (Central Processing Unit) 45A, a ROM (Read Only Memory) 45B, a RAM (Random Access Memory) 45C, etc., and functions as a computer. The CPU 45A reads out and executes various programs stored in the ROM 45B and the large-capacity storage device 43 to realize various functions.

[0093] The input / output unit 47 is a functional part that communicates information with the laser emitting and receiving device 33. The input / output unit 47 can transmit a control signal for controlling the operation of the laser emitting and receiving device 33 to the laser emitting and receiving device 33. The input / output unit 47 can also receive from the laser emitting and receiving device 33 a light receiving signal that is a signal received when the laser emitting and receiving device 33 receives reflected light.

[0094] Based on the received signals, the control unit 45 can calculate the distance between the object that reflected the irradiated lights LL1 and LL2 and the distance measuring device 30 or the automobile M. For example, the control unit 45 can calculate the distance using a Time Of Flight (TOF) method or a phase difference method.

[0095] The input / output unit 47 may be capable of communicating with other devices. For example, the input / output unit 47 may be capable of receiving information on whether a distance measurement operation is currently required from an external device. The control unit 45 may generate a control signal for controlling the laser emission / reception device 33 in response to the information on whether a distance measurement operation is required, and transmit the control signal to the laser emission / reception device 33 via the input / output unit 47.

[0096] In addition, the input / output unit 47 may be capable of communicating information with the wiper driving unit WPA, which is a driving unit of the wiper WP as a removal device. For example, when the control unit 45 detects the presence of a foreign object on the outer surface OS of the windshield FG, the control unit 45 may be capable of generating a control signal for causing the removal device to perform an operation to remove the foreign object, and transmitting the control signal to the wiper driving unit WPA via the input / output unit 47.

[0097] The detection of a foreign object on the outer surface OS of the windshield FG may be performed based on a light receiving signal, which is a signal received when reflected light is received by the laser emitting / receiving device 33. For example, when distance measurement processing is performed based on the light receiving signal, if an object is detected at a distance equal to or greater than a threshold, it may be determined that a foreign object is present on the outer surface OS of the windshield FG.

[0098] [Distance measurement control routine] A distance measurement operation control routine executed by the control unit 45 in order to realize a redundant and accurate distance measurement operation of the distance measuring device 30 of the first embodiment will be described below.

[0099] 11 is a flow diagram of an operation control routine R2, which is an example of a distance measurement operation control routine. For example, the operation control routine R2 is started and repeatedly executed when power is supplied to the distance measurement device 30. The operation control routine R2 may be started when the ACC power of the automobile in which the distance measurement device 30 is mounted is turned on.

[0100] In the operation control routine R2, distance measurement is normally performed using both the irradiation lights LL1 and LL2. If the wiper WP operates during distance measurement using both the irradiation lights LL1 and LL2, distance measurement using the irradiation light that passes through the area where the wiper WP is passing among the irradiation lights LL1 and LL2 is stopped. In other words, distance measurement is continued using only the irradiation light that does not have the wiper WP on its path.

[0101] When the operation control routine R2 is started, the control unit 45 first determines in step S21 whether or not a distance measurement operation is required in the automobile M. This determination may be made, for example, based on whether or not the automobile M is in an automatic driving state. Specifically, information on whether the automobile M is currently under automatic driving control or manual driving control may be obtained, and if the automobile M is under automatic driving control, it may be determined that a distance measurement operation is required.

[0102] In addition, the determination as to whether or not a distance measurement operation is required may be made by determining whether or not a distance measurement start operation has been performed by a passenger in the automobile M. In addition, the determination as to whether or not a distance measurement operation is required may be made based on the traveling speed of the automobile M or the current traveling position of the automobile M.

[0103] In step S21, if it is determined that the distance measurement operation is not required (step S21: NO), the operation control routine R1 is executed again from the beginning. In step S21, if it is determined that the distance measurement operation is required (step S21: YES), the control unit 45 starts distance measurement in a normal scanning mode in which the laser emission / reception device 33 emits the emission lights EL1 and EL2 to perform scanning (step S22). In this normal scanning mode, raster scanning may be performed to alternately scan the irradiation areas LR1 and LR2 with the irradiation lights LL1 and LL2.

[0104] After executing step S22, the control unit 45 judges in step S23 again whether or not a distance measurement operation is required in the automobile M. This judgment can be made in the same manner as the judgment in step S21 described above. If it is judged in step S23 that a distance measurement operation is not required (step S23: NO), the control unit 45 causes the laser emission / reception device 33 to stop emitting the emitted lights EL1 and EL2, and the distance measurement operation ends (step S24). After the end of step S24, the operation control routine R1 is executed again from the beginning.

[0105] When it is determined in step S23 that the distance measurement operation is still required (step S23: YES), the control unit 45 determines whether the wiper WP is operating or not (step S25). This determination can be made by detecting the wiper based on the light receiving signal from the laser emitting / receiving device 33. Specifically, for example, in distance measurement using either the irradiated light LL1 or LL2, when an object is detected at a distance closer than a predetermined threshold, it may be determined that the wiper WP is operating.

[0106] As described above, since the wiper driving unit WPA and the controller 40 are communicatively connected, it may be determined whether the wiper WP is operating based on a signal from the wiper driving unit WPA.

[0107] If it is determined in step S25 that the wiper WP is not operating (step S25: NO), the control unit 45 executes step S13 again to determine whether the distance measurement operation is still required.

[0108] In step S25, if it is determined that the wiper WP is operating (step S25: YES), the control unit 45 stops measuring the distance using the irradiation light LL1 and LL2 whose path includes the area through which the wiper is passing, and transitions to a wiper scanning mode, which is a mode in which measuring the distance is performed only using irradiation light that does not have any foreign objects on its path (step S26).

[0109] In the wiper scanning mode, the laser emitting / receiving device 33 may be caused to emit only one of the emitted light EL1 or EL2 depending on the current position of the wiper WP. That is, of the emitted light LL1 and LL2, only the emitted light to be used for distance measurement may be emitted to the laser emitting / receiving device 33. In addition, in the wiper scanning mode, both the emitted light EL1 and EL2 may be emitted to the laser emitting / receiving device 33, and only the reflected light of the emitted light LL1 and LL2 on whose path the wiper WP does not exist may be used for distance measurement.

[0110] After step S26 is executed, the control unit 45 judges in step S27 again whether or not a distance measurement operation is required in the automobile M. This judgment can be made in the same manner as the judgment in step S21 described above. If it is judged in step S27 that a distance measurement operation is not required (step S27: NO), the control unit 45 causes the laser emission / reception device 33 to stop emitting the emitted lights EL1 and EL2, and the distance measurement operation ends (step S24). After step S24 ends, the operation control routine R2 is executed again from the beginning.

[0111] If it is determined in step S27 that the distance measurement operation is still required (step S27: YES), the control unit 45 determines whether the wiper WP is still operating (step S28). This determination can be made in the same manner as the determination in step S25.

[0112] In step S28, when it is determined that the wiper WP is still in operation (step S28: YES), the control unit 45 executes step S27 again, that is, the distance measurement in the wiper scanning mode is continued.

[0113] In step S28, if it is determined that the operation of the wiper WP has stopped (step S28: NO), the control unit 45 returns to the normal scanning mode in which distance measurement is performed using both the irradiation lights LL1 and LL2, and continues distance measurement (step S29).

[0114] As described above, the distance measuring device 30 has a configuration in which the irradiated lights LL1 and LL2 exit the distance measuring device 30 via different paths, specifically, by passing through different parts of the windshield FG, while being irradiated onto substantially the same area outside the distance measuring device 30. In other words, the distance measuring device 30 has a redundant configuration in which the irradiated lights LL1 and LL2 can measure the distance to the same area.

[0115] When the operation control routine R2 is executed in the distance measuring device 30 having the above configuration, accurate distance measurement can be continued even when the wiper WP is operating on the automobile M. Specifically, even if the wiper WP is present in a portion through which one of the irradiated lights LL1 and LL2 passes, accurate distance measurement can be continued by measuring the distance using the other irradiated light.

[0116] In the above description, the front glass FG and the deflector 35 are formed separately, but the deflector 35 may be formed integrally with the front glass FG. For example, as shown in Fig. 12, the deflector 37 can be omitted by forming the deflectors 35A and 35B integrally in the front glass FG.

[0117] In addition, the control unit 45 of the distance measuring device 30 of the second embodiment may execute a routine similar to the operation control routine R1 of the first embodiment. In that case, for example, the wiper WP may be operated after step S15 to actively remove foreign matter.

[0118] [Variations] In the above embodiment, the deflection units 17A, 17B, 35A, and 35B are described as being capable of deflecting the emitted light beams EL1 and EL2 in a fixed direction. However, either or both of the deflection units 17A and 17B and either or both of the deflection units 35A and 35B may be variable deflection units having a function of deflecting the emitted light beams EL1 and EL2 in a variable direction. For example, the variable deflection units may be made of liquid crystal alignment control elements.

[0119] Fig. 13 is a top view of an automobile M equipped with a distance measuring device 10 in which the deflection unit 17B is a variable deflection unit in Example 1. Fig. 13 shows a case where the deflection direction of the deflection unit 17B is changed from the state in Fig. 1, that is, from the center line AX of the irradiation light in the Y direction.

[0120] For example, in the first embodiment, by making the deflection unit 17B a variable deflection unit, the emitted light EL2 may be deflected in the width direction of the automobile M, i.e., in the Y direction, according to the road conditions, and the irradiation light LL2 may be irradiated onto an area different from the irradiation light LL1. For example, when operating according to the above-mentioned operation control routine R1, in the normal scanning mode in which the irradiation lights LL1 and LL2 are redundantly usable for distance measurement without any problem, the deflection direction of the irradiation light LL2 may be changed to enable distance measurement of a plurality of areas.

[0121] The determination as to whether the irradiation light LL1 and the irradiation light LL2 are to be irradiated to different regions may be made based on, for example, a situation ahead of the automobile M that is prepared in advance or obtained by the distance measuring devices 10 and 30. The determination as to whether the irradiation light LL1 and the irradiation light LL2 are to be irradiated to different regions may be made based on, for example, map data.

[0122] In the above-described embodiment, the case where the emitted light EL1 and EL2 are deflected by the deflection units 17A, 17B, 35A, and 35B having a function of a transmissive deflection element has been described. However, the emitted light EL1 and EL2 may be deflected by a deflection unit having a function of a reflective deflection element and irradiated as the irradiation light LL1 and the irradiation light LL2.

[0123] The various configurations in the above-described embodiment are merely examples and can be appropriately selected depending on the application. [Explanation of symbols]

[0124] 10 Ranging device 11, 31 Case 11C,31C opening 13, 33 Laser emission / reception device 15 Protective plate 17, 35 deflection plate 17A, 35A First deflection section 17B, ​​35B Second deflection section 31E Open end WP Wiper

Claims

1. A light emitting portion that emits an output light; a light receiving unit that receives reflected light, which is the emitted light reflected by a distance measurement target; a housing that houses the light emitting unit and the light receiving unit, that forms an opening on an optical path of the emitted light, and that has an opening end that is formed along an inner surface of a light transmitting member of a moving body and has a shape that follows the inner surface of the light transmitting member; a deflection plate including a deflection portion that covers the opening at an end of the opening and deflects the emitted light; having the light emitting portion emits a first emitted light in a first direction and emits a second emitted light in a second direction; the deflection unit includes a first deflection unit that deflects the first emitted light, A distance measuring device, characterized in that a first illumination area onto which the first outgoing light deflected by the first deflection unit is irradiated and a second illumination area onto which the second outgoing light is irradiated at least partially overlap each other.

2. 2. The distance measuring device according to claim 1, wherein when the housing is placed on the movable body, the opening is covered by the light-transmitting member of the movable body, and the light-transmitting member and the deflection plate are formed integrally.

3. a second deflection unit that deflects the second emitted light, 3. The distance measuring device according to claim 2, wherein the second illumination area is an area illuminated with the second emitted light having passed through the second deflection section.

4. 4. The distance measuring device according to claim 3, further comprising a holding member for holding the first deflection unit or the second deflection unit.

5. A distance measuring device as described in any one of claims 1 to 4, characterized in that when an obstacle is present on the optical path of one of the first emitted light and the second emitted light, the light emitting section emits only the light contained in the other emitted light.

6. 6. The distance measuring device according to claim 1, further comprising a removing unit for removing an obstacle on an optical path of the first outgoing light and the second outgoing light.

7. the light receiving unit receives the first emitted light and the second emitted light reflected by the object to be measured, 7. A distance measuring device according to claim 1, wherein the light emitting section changes the emission mode of the first emitted light and the second emitted light depending on a reception result of the reflected first emitted light and the second emitted light.

8. the light emitting unit has a laser light source that emits the first emitted light and the second emitted light, 8. The distance measuring device according to claim 1, wherein the light emitting portion emits the first emitted light in a scanning manner in the first direction and emits the second emitted light in a scanning manner in a second direction.

9. 9. The distance measuring device according to claim 1, wherein the first deflection section is capable of deflecting the first emitted light in a variable direction.

Images