Distance measuring apparatus

Abstract

To provide a distance measuring device having high resistance to contamination in a path of light or electromagnetic waves for distance measurement, and to provide a distance measuring device capable of maintaining distance measurement accuracy even when an obstacle exists on the path of light or electromagnetic waves for distance measurement.SOLUTION: A light emitting unit that emits emission light, a light receiving unit that receives reflected light reflected by a distance measurement target, and an opening that houses the light emitting unit and the light receiving unit and is provided on an optical path of the emission light, A housing having an opening end portion that is formed along an inner surface of the light transmitting member of the moving body and has a shape along the inner surface of the light transmitting member, and a deflection plate that covers an opening at the opening end portion and includes a deflection unit that deflects emission light, in which the light emission unit emits first emission light in a first direction and emits second emission light in a second direction, the deflector includes a first deflector configured to deflect the first outgoing light, and a first irradiation region irradiated with the first outgoing light deflected by the first deflector and a second irradiation region irradiated with the second outgoing light deflected by the first deflector at least partially overlap 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 measure the distance to an object using light or electromagnetic waves have been used for some time. 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 multiple different areas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-145399 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 member such as a light-transmitting resin is provided to protect the device in the area through which the light or electromagnetic waves for distance measurement pass. 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] Furthermore, if a distance measuring device is installed inside a moving body such as a car and distance measurement of the outside world is performed, for example, through the windshield, the distance measurement accuracy may decrease or distance measurement 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 the 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 the 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 first emitted light in a first direction and emits second emitted light in a second direction, the deflection unit has a first deflection unit that deflects the first emitted light, and the first illumination area irradiated with the first emitted light deflected by the first deflection unit and the second illumination area irradiated with the second emitted light at least partially overlap each other. [Brief explanation 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. [Figure 2] FIG. 1 is a cross-sectional view of a distance measuring device according to a first embodiment. [Figure 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. [Figure 5] FIG. 3 is a diagram illustrating an operation control routine of the distance measuring device according to the first embodiment. [Figure 6] FIG. 10 is a cross-sectional view of a distance measuring device according to a modified example. [Figure 7] FIG. 10 is a top view of an automobile equipped with a distance measuring device according to a second embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a distance measuring device according to a second embodiment. [Figure 9] FIG. 10 is a side view of an automobile equipped with a distance measuring device according to a second embodiment. [Figure 10] FIG. 10 is a functional block diagram of a controller of a distance measuring device according to a second embodiment. [Figure 11] FIG. 10 is a diagram illustrating an operation control routine of the distance measuring device according to the second embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a distance measuring device according to a modified example. [Figure 13] FIG. 10 is a top view of a vehicle equipped with a distance measuring device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] [Configuration of distance measuring device] 1 is a top view of an automobile M equipped with a distance measuring device 10 according to a 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-to-rear direction of the automobile M is defined as the X direction, the left-to-right direction, i.e., the width direction, as the Y direction, and the up-to-down direction as the Z direction.

[0011] The distance measuring device 10 is a laser distance measuring device that measures distance by emitting laser light and receiving light that is 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 the center line AX along the front-to-rear direction of the automobile M when viewed from above. The distance measuring device 10 is configured to be able to emit laser light 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] 2 is a cross-sectional view of the distance measuring device 10 taken along a plane including the center line AX and the Z axis in FIG. 1. The housing 11 has a rectangular cylindrical portion 11A that extends in the longitudinal direction of the automobile M, i.e., has a cylindrical axis that runs along the X axis, and a rectangular bottom portion 11B that closes one of the openings of the cylindrical portion 11A. In other words, the housing 11 is a box-like body in which an opening 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 beam 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. The laser emitting / receiving device 13 also has, as a light receiving unit, 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 emission receiving device 13 is capable of emitting a first emitted light EL1 to a first emission region ER1 that is in a first directional range as seen from the laser emission receiving device 13. The laser emission receiving device 13 is also capable of emitting a second emitted light EL2 to a second emission region ER2 that is in a second directional range as seen from the laser emission receiving device 13. In other words, the laser emission receiving device 13 is capable of emitting the first emitted light EL1 in a first direction within the first directional range, and emitting the second emitted light EL2 in a second direction within the second directional range. The laser emission receiving device 13 is capable of scanning a pulsed laser toward the first emission region ER1 and the second emission 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 scanned sequentially by raster scanning. Alternatively, the entire first emission region ER1 and the entire second emission region ER2 may be scanned simultaneously by Lissajous scanning.

[0016] The protective plate 15 is a plate-shaped light-transmitting member such as a 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 of 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 exits 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 the 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 by the laser emission and reception device 13. A removal device for removing foreign matter adhering to the surface 15S of the protective plate 15 may be provided. For example, a wiper device (not shown) that can operate 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 also 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-like resin or glass material that is provided between the protection plate 15 and the laser emission and 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 and reception device 13. That is, the light emitted from the laser emission and reception device 13 passes through the deflection plate 17 and the protection plate 15 in this order before leaving the distance measuring device 10 and exiting the device. The reflected light received by the laser emission and reception device 13 passes through the protection plate 15 and the deflection plate 17 in this order before reaching the laser emission and 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 output light EL1 passes. The first deflection section 17A functions as a transmissive deflection element that transmits the first output 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 functions as 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 output light EL1 is deflected downward when passing through the first deflection unit 17A, and becomes the first irradiation light LL1 that is irradiated onto the first irradiation region LR1. In other words, the first irradiation region LR1 is an area that is irradiated with the first output light EL1 deflected by the first deflection unit 17A.

[0023] Furthermore, 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 onto 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 unit 17A and the second deflection unit 17B do not have to be built into the deflection plate 17. That is, the first deflection unit 17A and the second deflection unit 17B may be formed separately from the deflection plate 17, and the deflection plate 17 may hold these separate first deflection unit 17A and second deflection unit 17B.

[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 to hold them on the deflection plate 17. Alternatively, the members forming the deflection units 17A and 17B may be fixed to the surface of the deflection plate 17 by adhesive or the like, so that the deflection plate 17 holds the deflection units 17A and 17B.

[0027] Note that portions of deflection plate 17 other than first deflection unit 17A and second deflection unit 17B do not need to be light-transmitting because the emitted light beams EL1 and EL2 do not reach them. Also, first deflection unit 17A and second deflection unit 17B do not need to be formed within deflection plate 17, but only need to be held on the optical path of the first emitted light beam and the optical path of the second emitted light beam, respectively. Therefore, first deflection unit 17A and second deflection unit 17B may be formed from separate members, and may be held by other holding members fixed to housing 11, rather than by 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] Furthermore, 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 irradiated light LL1 is indicated by a two-dot chain line, and the second irradiated light LL2 is indicated by a dashed line.

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

[0032] As described above with reference to Figure 2, the irradiated light beams LL1 and LL2 are emitted from the aperture 11C (see Figure 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 approximately the same area, albeit with a slight deviation. In other words, the emitted light beams EL1 and EL2, which are emitted in two different directional ranges, become the irradiated light beams LL1 and LL2 that are irradiated onto approximately the same area.

[0033] The distance measuring device 10 has a configuration in which the irradiated light beams LL1 and LL2 exit the distance measuring device 10 via different paths, specifically by passing through different parts of the protective plate 15, and are 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 light beams that are irradiated onto the same area, and the distance to the same area can be measured using these multiple irradiated light beams.

[0034] Therefore, accurate distance measurement can be performed 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 light LL1 or LL2 passes is soiled, accurate distance measurement can be performed 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 performs distance measurement functions. 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. Alternatively, the controller 20 may be provided, for example, within the laser emission and reception device 13. In the following explanation, 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 mass storage device 23 is configured by, for example, a hard disk drive, a solid state drive (SSD), a flash memory, etc., and stores various programs such as an operating system and terminal software. Note that the various programs may be obtained, for example, from another server device or the like 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 controlling the laser emitting / receiving device 13 described below and executing processing for distance measurement) 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 and executes various programs stored in the ROM 25B and the large-capacity storage device 23, thereby realizing various functions.

[0040] The input / output unit 27 is a functional part that communicates information with the laser emission and reception device 13. The input / output unit 27 can transmit to the laser emission and reception device 13 a control signal that controls the operation of the laser emission and reception device 13. The input / output unit 27 can also receive from the laser emission and reception device 13 a light reception signal that is a signal received when the laser emission and reception 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 also be capable of communicating with other devices. For example, the input / output unit 27 may be capable of receiving information from an external device as to whether a distance measurement operation is currently required. The control unit 25 may generate a control signal for controlling the laser emission and reception device 13 in accordance with the information as to whether a distance measurement operation is required, and transmit the control signal to the laser emission and reception 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 that can remove 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 that removes 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 to cause 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 reflected light is received by the laser emitting / receiving device 13. For example, when distance measurement processing is performed using 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 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 also be started when the ACC power supply of the automobile in which the distance measuring device 10 is installed is turned on.

[0048] In the operation control routine R1, distance measurement is normally performed using both 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 irradiated light beams LL1 and LL2, distance measurement using the irradiated light beams LL1 and LL2 that pass through the area where the foreign object adheres is stopped. In other words, distance measurement continues using only the irradiated light beams that do not have a foreign object in their irradiation path.

[0049] When the operation control routine R1 is started, the control unit 25 first determines in step S11 whether a distance measurement operation is required in the automobile M. This determination may be made, for example, based on whether 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] Furthermore, the determination as to whether a distance measurement operation is required may be made by determining whether a distance measurement start operation has been performed by a passenger in the automobile M. Furthermore, the determination as to whether 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] If it is determined in step S11 that a distance measurement operation is not required (step S11: NO), the operation control routine R1 is executed again from the beginning. If it is determined in step S11 that a 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, which serves 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 determines again in step S13 whether a distance measurement operation is required for the automobile M. This determination can be made in the same manner as the determination in step S111 above. If it is determined 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 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.

[0053] If 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 along the paths of the irradiated light LL1 and LL2 (step S15). This determination can be made by detecting the foreign object based on the light reception signal from the laser emitting and receiving device 13. Specifically, for example, when an object is detected at a distance closer than a predetermined threshold 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.

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

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

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

[0057] After step S16 is executed, the control unit 25 determines again in step S17 whether or not a distance measurement operation is required for the automobile M. This determination can be made in the same manner as the determination in step S11 above. If it is determined 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 matter detected in step S15 remains (step S18). This determination can be made by detecting the foreign matter based on the light reception signal from the laser light emitting and receiving device 13. Specifically, for example, distance measurement may be attempted using irradiation light that is not being used in the single scan mode, and when an object is detected at a distance closer than a predetermined threshold, it may be determined that a foreign matter remains on the surface 15S of the protective plate 15.

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

[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 that can remove 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 measurement in single scan mode.

[0062] As described above, the distance measuring device 10 has a configuration in which the irradiated lights LL1 and LL2 generated by the emitted lights EL1 and EL2 from one laser emitting / receiving device 13 leave the distance measuring device 10 via different paths, specifically, by passing through different parts of the protective plate 15, and are irradiated onto approximately the same area outside the distance measuring device 10. In other words, the distance measuring device 10 has a redundant configuration in which the irradiated lights LL1 and LL2 can measure the distance to the same area.

[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 light beams LL1 and LL2 passes is soiled, accurate distance measurement can be continued by measuring the distance using the other irradiated light beam.

[0064] In the above description, an example has been given in which two deflection sections, 17A and 17B, are formed on the deflection plate 17, but the number of deflection sections may be one. For example, as shown in Fig. 6, only deflection section 17A may be formed, and only ER1 may be deflected. In this case, too, 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, the illumination lights LL1 and LL2 will be irradiated onto approximately the same area, as in the distance measuring device described above. [Example]

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

[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-to-rear direction of the automobile M is defined as the X direction, the left-to-right direction, i.e., the width direction, as the Y direction, and the up-to-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 laser light and receives light reflected by an object to measure distance. The distance measuring device 30 is mounted in the center 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 center line AX and the Z axis in Fig. 7. The automobile M is provided with a wiper device WP capable of removing foreign matter from the outer surface OS of the windshield FG.

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

[0071] Opening edge 31E, which is the opening end that forms opening 31C of housing 31, has a shape that follows the inner surface IS of windshield FG. That is, opening edge 31E has a shape that slopes downward as it approaches 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 beam 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 Example 1, and includes, for example, a laser element that emits laser light and a MEMS mirror that reflects the laser light in a variable direction. The laser emitting / receiving device 33 also includes, as a light receiving unit, a light receiving element that receives and detects reflected light of the emitted laser light reflected by an object. For example, the laser emitting / receiving device 33 is a so-called laser LiDER device.

[0073] The laser emission receiving device 33 can emit a first emission light EL1 to a first emission region ER1 that is in a first directional range as seen from the laser emission receiving device 33. The laser emission receiving device 33 can also emit a second emission light EL2 to a second emission region ER2 that is in a second directional range as seen from the laser emission receiving device 33. The laser emission receiving device 33 can scan a pulsed laser toward the first emission region ER1 and the second emission 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 scanned sequentially by raster scanning. Alternatively, the entire first emission region ER1 and the entire second emission region ER2 may be scanned simultaneously by Lissajous scanning.

[0075] The deflection plate 35 is a light-transmitting member made of a plate-like resin or glass material and 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 exits the distance measuring device 30 to the outside. Furthermore, 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 output light EL1 passes. The first deflection section 35A functions as a transmissive deflection element that transmits the first output light EL1 while deflecting 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 functions as 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 onto 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 onto 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 rays that are irradiated in the same direction.

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

[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 portion of the automobile M, including the windshield FG. In Fig. 9, the first irradiated light LL1 is indicated by a two-dot chain line, and the second irradiated light LL2 is indicated 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, i.e., 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 Figure 8, the irradiated light beams LL1 and LL2 are emitted from the aperture 11C (see Figure 2) of the distance measuring device via different paths through different parts of the windshield FG, but from a macroscopic perspective, they are irradiated onto approximately the same area, albeit slightly offset from each other. In other words, the emitted light beams EL1 and EL2, which are emitted in two different directional ranges, become the irradiated light beams LL1 and LL2 that are irradiated onto approximately the same area.

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

[0085] Furthermore, the open end 31E of the distance measuring device 30 has a shape that conforms to 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 also be installed by partially or completely submerging it in the dashboard, i.e., buried in the dashboard.

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

[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 performs the distance measurement 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. Alternatively, the controller 40 may be provided, for example, within the laser emission and reception device 33. In the following explanation, 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 also be communicably connected to a wiper driving unit WPA that drives the wipers WP. Specifically, the wiper devices may be driven by signals from the controller 40. The controller 40 may also be capable of detecting whether the wiper devices are 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 mass storage device 43 is configured by, for example, a hard disk drive, a solid state drive (SSD), a flash memory, etc., and stores various programs such as an operating system and terminal software. Note that the various programs may be obtained, for example, from another server device or the like 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 emitting / receiving device 33 described below and executing processing for distance measurement) 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 and executes various programs stored in the ROM 45B and the large-capacity storage device 43, thereby realizing various functions.

[0093] The input / output unit 47 is a functional part that communicates information with the laser emission and reception device 33. The input / output unit 47 can transmit a control signal to the laser emission and reception device 33 to control the operation of the laser emission and reception device 33. The input / output unit 47 can also receive a light reception signal from the laser emission and reception device 33, which is a signal sent when the laser emission and reception 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 also be capable of communicating with other devices. For example, the input / output unit 47 may be capable of receiving information from an external device as to whether a distance measurement operation is currently required. The control unit 45 may generate a control signal for controlling the laser emission and reception device 33 in accordance with the information as to whether a distance measurement operation is required, and transmit the control signal to the laser emission and reception device 33 via the input / output unit 47.

[0096] Furthermore, the input / output unit 47 may be capable of communicating information with a wiper driving unit WPA, which is a driving unit for the wiper WP serving 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 light emitting / receiving device 33. For example, when distance measurement processing is performed using 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 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 measuring device 30. The operation control routine R2 may also be started when the ACC power supply of the automobile in which the distance measuring device 30 is installed is turned on.

[0100] In the operation control routine R2, distance measurement is normally performed using both the irradiated light beams LL1 and LL2. If the wiper WP operates during distance measurement using both the irradiated light beams LL1 and LL2, distance measurement using the irradiated light beams LL1 and LL2 that pass through the area where the wiper WP is passing is stopped. In other words, distance measurement continues using only the irradiated light beams that are not in the path of the irradiated light beam.

[0101] When the operation control routine R2 is started, the control unit 45 first determines in step S21 whether a distance measurement operation is required in the automobile M. This determination may be made, for example, based on whether 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] Furthermore, the determination as to whether a distance measurement operation is required may be made by determining whether a distance measurement start operation has been performed by a passenger in the automobile M. Furthermore, the determination as to whether 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 a 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 a distance measurement operation is required (step S21: YES), the control unit 45 starts distance measurement in a normal scanning mode in which the laser emitting and receiving device 33 emits the emitted light beams 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 light beams LL1 and LL2.

[0104] After executing step S22, the control unit 45 determines again in step S23 whether a distance measurement operation is required for the automobile M. This determination can be made in the same manner as the determination in step S21 above. If it is determined 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 light EL1 and EL2, and the distance measurement operation ends (step S24). After step S24 ends, the operation control routine R1 is executed again from the beginning.

[0105] If 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 (step S25). This determination can be made by detecting the wiper based on the light reception signal from the laser light emitting / receiving device 33. Specifically, for example, in distance measurement using either the irradiated light LL1 or LL2, it may be determined that the wiper WP is operating when an object is detected at a distance closer than a predetermined threshold.

[0106] As described above, the wiper driving unit WPA and the controller 40 are connected so as to be able to communicate with each other, and therefore, it may be determined whether the wiper WP is operating or not 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 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 this wiper scanning mode, the laser emission and reception device 33 may be configured to emit only one of the emitted beams EL1 and EL2 depending on the current position of the wiper WP. That is, of the emitted beams LL1 and LL2, only the emitted beam to be used for distance measurement may be emitted to the laser emission and reception device 33. Also, in the wiper scanning mode, the laser emission and reception device 33 may be configured to emit both the emitted beams EL1 and EL2, and only the reflected beam of the emitted beams LL1 and LL2 that is not on the path of the wiper WP may be used for distance measurement.

[0110] After step S26 is executed, the control unit 45 determines again in step S27 whether or not a distance measurement operation is required for the automobile M. This determination can be made in the same manner as the determination in step S21 above. If it is determined 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 light beams 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] If it is determined in step S28 that the wiper WP is still operating (step S28: YES), the control unit 45 executes step S27 again, that is, distance measurement in the wiper scanning mode continues.

[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 light beams 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 approximately 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 light beams LL1 and LL2 can measure the distance to the same area.

[0115] In the distance measuring device 30 having the above configuration, when the operation control routine R2 is executed, accurate distance measurement can be continued even when the wipers WP are operating on the automobile M. Specifically, even if the wipers WP are present in an area 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 case where the windshield FG and the deflector 35 are formed separately has been described as an example, but the deflector 35 may be formed integrally with the windshield FG. For example, as shown in Fig. 12, by integrally forming the deflectors 35A and 35B within the windshield FG, it is possible to omit the deflector 37.

[0117] Furthermore, 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 this 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 capable of deflecting the emitted light beams EL1 and EL2 in a variable direction. For example, the variable deflection units may be liquid crystal alignment control elements.

[0119] Fig. 13 is a top view of an automobile M equipped with the 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 irradiation light center line AX to the Y direction.

[0120] For example, in the first embodiment, by using a variable deflection unit as the deflection unit 17B, the emitted light EL2 may be deflected in the width direction of the automobile M, i.e., in the Y direction, depending on the road conditions, so that the irradiation light LL2 is irradiated onto an area different from that for the irradiation light LL1. For example, when operating according to the above-described operation control routine R1, in the normal scanning mode, which is a redundant state in which the irradiation lights LL1 and LL2 can be used for distance measurement without any problems, the deflection direction of the irradiation light LL2 may be changed to enable distance measurement of multiple areas.

[0121] The determination of whether to irradiate the illumination light LL1 and the illumination light LL2 onto different areas may be made based on, for example, a situation ahead of the automobile M that has been prepared in advance or that is obtained by the distance measuring devices 10 and 30. The determination of whether to irradiate the illumination light LL1 and the illumination light LL2 onto different areas may be made based on, for example, map data.

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

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

[0124] 10 Ranging device 11, 31 cabinet 11C,31C opening 13, 33 Laser emission and 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 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, 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; and the light emitting unit emits a first emitted light in a first direction and 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. a second deflection unit that deflects the second emitted light, 2. The distance measuring device according to claim 1, wherein the second illumination area is an area illuminated by the second emitted light that has passed through the second deflection unit.

3. 3. The distance measuring device according to claim 2, further comprising a holding member for holding the first deflection unit or the second deflection unit.

4. A distance measuring device as described in any one of claims 1 to 3, characterized in that 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 deflector are formed integrally.

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 unit emits only the light contained in the other emitted light.

6. 6. A distance measuring device according to claim 1, further comprising a removal unit for removing an obstacle on the optical path of said first emitted light and said second emitted 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 unit changes the emission modes of the first emitted light and the second emitted light depending on the reception results 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 unit emits the first emitted light in a scanning manner in the first direction and emits the second emitted light in a scanning manner in the second direction.

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

Images