Distance measuring device

Abstract

The present invention provides a distance measuring device that is highly resistant to contamination in the path of light or electromagnetic waves used for distance measurement, and a distance measuring device that can maintain distance measurement accuracy even when obstacles are present in the path of light or electromagnetic waves used for distance measurement. [Solution] The distance measuring device of the present invention comprises a light emitting unit that emits emitted light, a light receiving unit that receives reflected light which is emitted light reflected by a distance measuring object, a housing that houses the light emitting unit and the light receiving unit and has an opening end that forms an opening provided on the optical path of the emitted light, and a deflection plate equipped with 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, and the deflection unit has a first deflection unit that deflects the first emitted light, and the first illumination area irradiated by the first emitted light deflected by the first deflection unit and the second illumination area irradiated by the second emitted light overlap each other in at least a part.

Description

Technical Field

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

Background Art

[0002] Conventionally, distance measuring devices that measure the distance to an object using light or electromagnetic waves have been used. For example, Patent Document 1 discloses a radar device that switches the emission direction of a radar beam by a dielectric lens and performs detection in a plurality of different regions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in the case of a distance measuring device that measures the distance to an object using light or electromagnetic waves, a light-transmissive member such as a light-transmissive resin for device protection is provided in the region through which the light or electromagnetic waves for distance measurement pass. If such a portion through which light or electromagnetic waves pass becomes contaminated, the accuracy of distance measurement may decrease or distance measurement may become difficult.

[0005] Further, when the distance measuring device is installed in a room of a moving body such as an automobile and distance measurement of the outside world is performed through, for example, a windshield, the accuracy of distance measurement may decrease or distance measurement may become difficult during the operation of the wiper.

[0006] The present invention has been made in view of the above points, and an object thereof is to provide a distance measuring device having high resistance to contamination in the path of light or electromagnetic waves for distance measurement, for example. Another object of the present invention is to provide a distance measuring device capable of maintaining the distance measurement accuracy even when an obstacle exists in the path of light or electromagnetic waves for distance measurement, for example. [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 emitted light reflected by a distance measuring object; a housing that houses the light emitting unit and the light receiving unit and has an opening end that forms an opening provided on the optical path of the emitted light; and a deflection plate equipped with 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, and the deflection unit has a first deflection unit that deflects the first emitted light, and at least a portion of the first illumination area irradiated by the first emitted light deflected by the first deflection unit and the second illumination area irradiated by the second emitted light overlap each other. [Brief explanation of the drawing]

[0008] [Figure 1] This is a top view of an automobile equipped with a distance measuring device according to Example 1. [Figure 2] This is a cross-sectional view of the distance measuring device according to Example 1. [Figure 3] This is a side view of an automobile equipped with a distance measuring device according to Example 1. [Figure 4] This is a functional block diagram of the controller for the distance measuring device according to Example 1. [Figure 5] This figure shows the operation control routine of the distance measuring device according to Example 1. [Figure 6] This is a cross-sectional view of a modified rangefinder. [Figure 7] This is a top view of a vehicle equipped with a distance measuring device according to Example 2. [Figure 8] This is a cross-sectional view of the distance measuring device according to Example 2. [Figure 9] This is a side view of an automobile equipped with a rangefinder according to Example 2. [Figure 10] This is a functional block diagram of the controller for the distance measuring device according to Example 2. [Figure 11] This figure shows the operation control routine of the distance measuring device according to Example 2. [Figure 12]This is a cross-sectional view of a modified rangefinder. [Figure 13] This is a top view of a vehicle equipped with a modified rangefinder. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below. In the following description, the case in which the range measuring device is mounted on an automobile, which is an example of a mobile body, will be explained. [Examples]

[0010] [Configuration of the rangefinder] Figure 1 is a top view of a vehicle M equipped with a distance measuring device 10 according to Embodiment 1. Embodiment 1 describes the case where the distance measuring device 10 is attached to the front bumper portion of the vehicle M. In the following description, the front-rear direction of the vehicle M is the X direction, the left-right direction (i.e., the width direction) is the Y direction, and the up-down direction is the Z direction.

[0011] The distance measuring device 10 is a laser distance measuring device that emits laser light and receives reflected light from an object to measure distance. The distance measuring device 10 is mounted on the central part of the front end of the automobile M. In other words, the distance measuring device 10 is mounted so as to coincide 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 emit laser light toward the illumination area LR in front of the automobile M. In Figure 1, as an example, the case in which the illumination area LR is a region that is symmetrical with respect to the center line AX when viewed from above the automobile M is shown.

[0012] Figure 2 is a cross-sectional view of the distance measuring device 10 in a plane containing the center line AX and the Z axis of Figure 1. The housing 11 has a rectangular cylindrical portion 11A that extends in the front-rear direction of the automobile M, i.e., has a cylindrical axis in the direction 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-shaped body with an opening 11C formed therein.

[0013] At the center of the inner surface 11S of the bottom 11B of the housing 11, a laser emission and reception device 13 as a light emission unit capable of variably emitting a pulsed laser toward the opening 11C is provided. The laser emission and reception 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. Further, the laser emission and reception device 13 as a light reception unit has a light reception element (not shown) that can receive and detect the reflected light obtained by reflecting the emitted laser light by an object. For example, the laser emission and reception device 13 is a so-called laser LiDER device.

[0014] The laser emission and reception device 13 can emit a first emission light EL1 to a first emission region ER1 within a first direction range as viewed from the laser emission and reception device 13. Further, the laser emission and reception device 13 can emit a second emission light EL2 to a second emission region ER2 within a second direction range as viewed from the laser emission and reception device 13. In other words, the laser emission and reception device 13 can emit the first emission light EL1 in a first direction within the first direction range, and can emit the second emission light EL2 in a second direction within the second direction range. The laser emission and reception device 13 can scan the pulsed laser toward the first emission region ER1 and the second emission region ER2.

[0015] Note that 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. Further, the entire first emission region ER1 and the entire second emission region ER2 may be scanned at once by Lissajous scanning.

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

[0017] The emitted light from the laser emission / receiving 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 / receiving device 13 also passes through the protective plate 15 and reaches the laser emission / receiving device 13 from the outside. The protective plate 15 has the function of preventing foreign matter from entering the distance measuring device 10 while allowing the emitted light from the laser emission / receiving device 13 and the reflected light to the laser emission / receiving device 13 to pass through. 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 shape that is convex toward the outside of the housing 11, that is, convex toward the direction of emission of the emitted light EL1 and EL2 from the laser emission and receiving device 13.

[0019] The deflection plate 17 is a translucent material made of a plate-shaped resin or glass material, placed between the protective plate 15 inside the housing 11 and the laser emission / receiving device 13. The translucent material used for the deflection plate is a material that transmits light of wavelengths EL1 and EL2 emitted by the laser emission / receiving device 13. That is, the light emitted from the laser emission / receiving device 13 passes through the deflection plate 17 and then the protective plate 15 in that order before exiting the rangefinder 10 to the outside. Also, the reflected light received by the laser emission / receiving device 13 passes through the protective plate 15 and then the deflection plate 17 in that order before reaching the laser emission / receiving device 13 from the outside.

[0020] A first deflection portion 17A is formed in the portion of the deflection plate 17 through which the first emitted light EL1 is transmitted. The first deflection portion 17A functions as a transmissive deflection element that deflects the first emitted light EL1 downward while transmitting it. The first deflection portion 17A may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0021] A second deflection portion 17B is formed in the portion of the deflection plate 17 through which the second emitted light EL2 is transmitted. The second deflection portion 17B functions as a transmissive deflection element that deflects the second emitted light EL2 upward while transmitting it. The second deflection portion 17B may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0022] The first emitted light EL1 is deflected downward as it passes through the first deflection unit 17A, becoming the first irradiation light LL1 that irradiates the first irradiation area LR1. In other words, the first irradiation area LR1 is the area irradiated by the first emitted light EL1 that has been deflected by the first deflection unit 17A.

[0023] Furthermore, the second emitted light EL2 is deflected downward as it passes through the second deflection unit 17B, becoming the second illumination light LL2 that irradiates the second illumination region LR2. In other words, the second illumination region LR2 is the region irradiated by the second emitted light EL2 that has been deflected by the second deflection unit 17B.

[0024] As described above, a first deflection portion 17A and a second deflection portion 17B are 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] Furthermore, the first deflection section 17A and the second deflection section 17B do not necessarily have to be incorporated 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 these separate first deflection section 17A and second deflection section 17B.

[0026] In this case, holes may be formed in the deflection plate 17 at the locations where the first deflection portion 17A and the second deflection portion 17B are located in Figure 2, and the members forming the deflection portions 17A and 17B may be fitted into these holes so that the deflection plate 17 can hold them. Alternatively, the members forming the deflection portions 17A and 17B may be fixed to the surface of the deflection plate 17 by adhesive or other means, so that the deflection plate 17 can hold the deflection portions 17A and 17B.

[0027] Furthermore, the parts of the deflection plate 17 other than the first deflection portion 17A and the second deflection portion 17B do not need to be translucent, as the emitted light EL1 and EL2 do not reach them. Also, the first deflection portion 17A and the second deflection portion 17B do not need to be formed within the deflection plate 17, but may be held on the optical path of the first emitted light and the optical path of the second emitted light, respectively. Therefore, the first deflection portion 17A and the second deflection portion 17B may be formed from separate members and held by other holding members fixed to the housing 11, rather than being held by the deflection plate 17.

[0028] In the cross-section shown in Figure 2, the center line CX1 of the first irradiation region LR1 and the center line CX2 of the second irradiation region LR2 are parallel to each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are groups of light rays irradiated in the same direction.

[0029] Furthermore, the first irradiation light LL1 and the second irradiation light LL2 are irradiated to the outside through a different part of the protective plate 15. In other words, when passing through the protective plate 15, the first irradiation light LL1 and the second irradiation light LL2 pass through different paths.

[0030] Figure 3 is a side view of the automobile M equipped with the rangefinder 10. In Figure 3, the front portion of the automobile M is shown in an enlarged view. In Figure 3, the first illumination light LL1 is shown by a dashed line, and the second illumination light LL2 is shown by a dashed line.

[0031] As shown in Figure 3, the first irradiation light LL1 and the second irradiation light LL2 irradiate a region that is slightly offset but almost overlapping. In other words, the first irradiation light LL1 and the second irradiation light LL2 irradiate almost the same region. To put it another way, the first irradiation region LR1 and the second irradiation region LR2 overlap each other in at least part.

[0032] As described above with respect to Figure 2, the irradiated light LL1 and LL2 exit from the aperture 11C of the rangefinder (see Figure 2) through different parts of the protective plate 15 and take different paths. However, macroscopically, they irradiate almost the same area, albeit slightly offset. In other words, the emitted light EL1 and EL2, which are emitted in two different directional ranges, become the irradiated light LL1 and LL2 that irradiate almost the same area.

[0033] In the distance measuring device 10, the irradiated light LL1 and LL2 are emitted from the distance measuring device 10 via different paths, specifically passing through different parts of the protective plate 15, while irradiating approximately the same area outside the distance measuring device 10. In other words, the distance measuring device 10 has a redundant configuration in which multiple irradiated lights are generated by one laser emission / receiving device 13 and irradiate the same area, and these multiple irradiated lights enable distance measurement to be taken in the same area.

[0034] Therefore, even if the protective plate 15 of the distance measuring device 10 is partially contaminated, accurate distance measurement is still possible. Specifically, even if the portion through which either the illuminating light LL1 or LL2 passes is contaminated, accurate distance measurement is still possible by using the other illuminating light.

[0035] [Controller Configuration] Figure 4 shows the configuration of the controller 20, which is responsible for controlling the light emission of the laser emission receiver 13 of the distance measuring device 10 and for the distance measuring function. The controller 20 may be provided separately from the laser emission receiver 13 and be connected to the laser emission receiver 13 for communication purposes. Alternatively, the controller 20 may be provided within the laser emission receiver 13. In the following description, the case in which the controller 20 is provided separately from the laser emission receiver 13 will be described as an example.

[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 via a system bus 21, for example.

[0037] The large-capacity storage device 23 is composed of, for example, a hard disk drive, an SSD (solid state drive), flash memory, etc., and stores various programs such as the operating system and terminal software. These programs may be retrieved from, for example, other server devices via a network, or they 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 emission and receiving device 13 and for performing distance measurement, as described later) 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 composed of a CPU (Central Processing Unit) 25A, ROM (Read Only Memory) 25B, 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 mass storage device 23 to realize various functions.

[0040] The input / output unit 27 is a functional part that communicates information with the laser emission / receiving device 13. The input / output unit 27 can transmit control signals to the laser emission / receiving device 13 to control its operation. The input / output unit 27 can also receive received signals from the laser emission / receiving device 13, which are signals that occur when the laser emission / receiving device 13 receives reflected light.

[0041] The control unit 25 can calculate the distance between the object reflecting the irradiated light LL1 and LL2 and the distance measuring device 10 or the automobile M based on the received signal. For example, the control unit 25 can calculate this distance using the TOF (Time of Flight) method or the phase difference method.

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

[0043] Furthermore, the distance measuring device 10 may be equipped with a removal device, such as a wiper, capable of removing foreign matter adhering to the surface 15S of the protective plate 15. In other words, the distance measuring device 10 may be equipped with a removal means for removing obstacles in the optical paths of the first and second irradiation beams. In that case, the input / output unit 27 may be able to communicate with the removal device.

[0044] For example, the control unit 25 may, when it detects the presence of foreign matter on the surface 15S of the protective plate 15, generate a control signal to cause the removal device to perform an operation to remove the foreign matter, and transmit the control signal to the removal device via the input / output unit 27.

[0045] Detection of foreign matter on the surface 15S of the protective plate 15 may be performed based on a received signal, which is a signal obtained when the laser emission / receiving device 13 receives reflected light. For example, if distance measurement processing is performed based on the received signal, and an object close to the user is detected at a distance greater than a threshold, it may be determined that a foreign matter is present on the surface 15S of the protective plate 15.

[0046] [Distance measurement operation control routine] The following describes the distance measurement operation control routine executed in the control unit 25 to realize redundant distance measurement operations of the distance measuring device 10 in Example 1.

[0047] Figure 5 is a flowchart of an operation control routine R1, which is an example of a distance measurement operation control routine. For example, operation control routine R1 is started when power is supplied to the distance measuring device 10 and is executed repeatedly. Operation control routine R1 may also be started when the ACC power of the vehicle on 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 the illuminating light LL1 and LL2. If foreign matter adheres to the surface 15S of the protective plate 15 while distance measurement is being performed using both illuminating light LL1 and LL2, the distance measurement using the illuminating light that passes through the area where the foreign matter is attached is stopped. In other words, distance measurement continues using only the illuminating light that does not have foreign matter in its 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 for the vehicle M. This determination may be made, for example, by determining whether or not the vehicle M is in an automatic driving state. Specifically, information may be obtained on whether the vehicle M is currently under automatic driving control or manual driving control, and it may be determined that a distance measurement operation is required if it is under automatic driving control.

[0050] Furthermore, the determination of whether or not a range measurement operation is required may be made by determining whether or not the occupant of the vehicle M has initiated the range measurement operation. Alternatively, the determination of whether or not a range measurement operation is required may be made based on the vehicle M's speed or its current position.

[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 normal scanning mode, instructing the laser emission / receiving device 13 to emit emission lights EL1 and EL2 and perform scanning (step S12). In this normal scanning mode, raster scanning may be performed to alternately scan the irradiation areas LR1 and LR2 with irradiation lights LL1 and LL2. That is, the control unit 25 causes the laser emission / receiving device 13, which acts as a light emission unit, to emit the first emission light EL and the second emission light EL2.

[0052] After step S12 is completed, in step S13, the control unit 25 determines whether or not a distance measurement operation is required again in the vehicle M. This determination may be made in the same way as the determination in step S111. If it is determined in step S13 that a distance measurement operation is not required (step S13: NO), the control unit 25 instructs the laser emission / receiving device 13 to stop emitting the emitted light EL1 and EL2, and the distance measurement operation ends (step S14). After step S14 is completed, the operation control routine R1 is executed again from the beginning.

[0053] In step S13, if it is determined that a distance measurement operation is still required (step S13: YES), the control unit 25 determines whether or not there is foreign matter on the surface 15S of the protective plate 15 along the path of the irradiated light LL1 and LL2 (step S15). This determination can be made by detecting the foreign matter based on the received signal from the laser emission receiver 13. Specifically, for example, in distance measurement using either the irradiated light LL1 or LL2, if an object closer than a predetermined threshold is detected, it may be determined that there is foreign matter on the surface 15S of the protective 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] In step S15, if it is determined that a foreign object is present (step S15: YES), the control unit 25 stops measuring the distance using the irradiation light LL1 and LL2 that includes the region where the foreign object is present in its path, and switches to single-scan mode, which is a mode in which the distance is measured using only the irradiation light that does not contain a foreign object in its path (step S16).

[0056] In this single-scan mode, the laser output / receiving device 13 may emit only either the output light EL1 or EL2. That is, of the illumination lights LL1 and LL2, only the output light used for distance measurement may be emitted to the laser output / receiving device 13. Alternatively, in single-scan mode, the laser output / receiving device 13 may emit both the output light EL1 and EL2, and only the reflected light of either the illumination light LL1 or LL2 may be used for distance measurement.

[0057] After step S16 is executed, in step S17, the control unit 25 determines whether or not a distance measurement operation is required again in the vehicle M. This determination may be made in the same way as the determination in step S11. If it is determined in step S17 that a distance measurement operation is not required (step S17: NO), the control unit 25 instructs the laser emission / receiving device 13 to stop emitting the emitted light EL1 and EL2, and the distance measurement operation ends (step S14). After the completion of step S14, the operation control routine R1 is executed again from the beginning.

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

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

[0060] If it is determined in step S18 that no foreign matter remains (step S18: NO), the control unit 25 returns to the normal scanning mode, which uses both the irradiated light LL1 and LL2 to measure the distance, and continues measuring the distance (step S19).

[0061] Furthermore, 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, the removal operation to remove such 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 irradiation lights LL1 and LL2 generated by the emitted lights EL1 and EL2 from one laser emission / receiving device 13 are emitted from the distance measuring device 10 via different paths, specifically passing through different parts of the protective plate 15, and irradiating substantially 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 using the irradiation 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 contaminated. Specifically, even if the portion through which one of the illumination light LL1 or LL2 is transmitted is contaminated, accurate distance measurement can be continued by using the other illumination light.

[0064] In the above explanation, the case in which two deflection sections, 17A and 17B, are formed on the deflection plate 17 was described as an example, but there may be only one deflection section. For example, as shown in Figure 6, only the deflection section 17A may be formed so that only ER1 is deflected. In this case as well, if the emitted light EL1 is deflected so that the centerlines CX1 and CX2 of the irradiated light LL1 and LL2 that have passed through the deflection plate 17 become parallel, the irradiated light LL1 and LL2 will irradiate approximately the same area, similar to the distance measuring device described above. [Examples]

[0065] The distance measuring device 30 of Embodiment 2 of the present invention will be described below.

[0066] [Configuration of the rangefinder] Figure 7 is a top view of a vehicle M equipped with the rangefinder 30 according to Embodiment 2. Embodiment 2 describes the case in which the rangefinder 30 is mounted inside the windshield FG of the vehicle M. In the following description, the front-rear direction of the vehicle M is the X direction, the left-right direction (i.e., the width direction) is the Y direction, and the up-down direction is the Z direction.

[0067] Similar to the distance measuring device 10 in Example 1, the distance measuring device 30 is a laser distance measuring device that emits laser light and receives reflected light from an object to measure distance. The distance measuring device 30 is mounted in the central part of the inside of the windshield FG of the automobile M. In other words, the distance measuring device 30 is mounted so as to coincide with the center line AX along the front-to-rear direction of the automobile M when viewed from above.

[0068] The distance measuring device 30 is configured to emit laser light toward the illumination area LR in front of the automobile M. Figure 7 shows, as an example, the case where the illumination area LR is a region that is symmetrical with respect to the center line AX when viewed from above the automobile M.

[0069] Figure 8 is a cross-sectional view of the distance measuring device 30 in a plane containing the center line AX and the Z axis of Figure 7. The automobile M is equipped 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 vertically in the 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 cylindrical portion 11A. In other words, the housing 31 is a box-shaped body with an opening 31C formed therein.

[0071] The opening end 31E, which forms the opening 31C of the housing 31, has a shape that conforms to the inner surface IS of the windshield FG. That is, the opening end 31E has a sloping shape that slopes downward as it goes towards the front of the automobile M. In this embodiment, the opening end 31E is covered by the windshield FG.

[0072] A laser emission and receiving device 33 is provided in the center of the inner surface S31 of the bottom 31B of the housing 31, capable of directionally emitting a pulsed laser toward the opening 31C. The laser emission and receiving device 33 is similar to the laser emission and receiving device 13 of Embodiment 1, and for example, has a laser element that emits laser light and a MEMS mirror that reflects the laser light in a directional manner. The laser emission and receiving device 33, as a light receiving unit, has a light receiving element capable of receiving and detecting reflected light that has been reflected by an object from the emitted laser light. For example, the laser emission and receiving device 33 is a so-called laser LiDER device.

[0073] The laser emission / receiving device 33 is capable of emitting a first emission beam EL1 into a first emission region ER1 that is within a first directional range as viewed from the laser emission / receiving device 33. The laser emission / receiving device 33 is also capable of emitting a second emission beam EL2 into a second emission region ER2 that is within a second directional range as viewed from the laser emission / receiving device 33. The laser emission / receiving device 33 is capable of scanning the pulsed laser toward the first emission region ER1 and the second emission region ER2.

[0074] The scanning method for 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 using raster scanning. Alternatively, the entire first emission region ER1 and the entire second emission region ER2 may be scanned together using Lissajous scanning.

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

[0076] A first deflection portion 35A is formed in the portion of the deflection plate 35 through which the first emitted light EL1 is transmitted. The first deflection portion 35A functions as a transmissive deflection element that deflects the first emitted light EL1 forward while transmitting it. The first deflection portion 35A may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0077] A second deflection portion 35B is formed in the portion of the deflection plate 35 through which the second emitted light EL2 is transmitted. The second deflection portion 35B functions as a transmissive deflection element that deflects the second emitted light EL2 forward while transmitting it. The second deflection portion 35B may be, for example, a diffraction grating, a Fresnel lens, a hologram, or a dielectric lens.

[0078] The first emitted light EL1 is deflected forward as it passes through the first deflection section 35A, becoming the first illumination light LL1 that irradiates the first illumination area LR1. Similarly, the second emitted light EL2 is deflected forward as it passes through the second deflection section 35B, becoming the second illumination light LL2 that irradiates the second illumination area LR2.

[0079] In the cross-section shown in Figure 8, the center line CX1 of the first irradiation region LR1 and the center line CX2 of the second irradiation region LR2 are parallel to each other. That is, the first irradiation light LL1 and the second irradiation light LL2 are groups of light rays irradiated in the same direction.

[0080] Furthermore, the first irradiating light LL1 and the second irradiating light LL2 are emitted to the outside through different parts of the windshield FG. In other words, when passing through the windshield FG, the first irradiating light LL1 and the second irradiating light LL2 pass through different paths.

[0081] Figure 9 is a side view of automobile M equipped with a rangefinder 30. In Figure 9, the front area of ​​automobile M, including the windshield FG, is shown in an enlarged view. In Figure 9, the first illumination light LL1 is shown by a dashed line, and the second illumination light LL2 is shown by a dashed line.

[0082] As shown in Figure 9, the first irradiation light LL1 and the second irradiation light LL2 irradiate a region that is slightly offset but almost overlapping. In other words, the first irradiation light LL1 and the second irradiation light LL2 irradiate almost the same region.

[0083] As described above with respect to Figure 8, the irradiated light LL1 and LL2 exit from the aperture 11C of the rangefinder (see Figure 2) through different parts of the windshield FG and via different paths. However, macroscopically, they illuminate almost the same area, albeit slightly offset. In other words, the emitted light EL1 and EL2, which are emitted in two different directional ranges, become the irradiated light LL1 and LL2 that illuminate almost the same area.

[0084] In the distance measuring device 30, the emitted light LL1 and LL2 travel through different paths from the distance measuring device 30, specifically passing through different parts of the windshield FG, while still illuminating approximately the same area outside the distance measuring device 30. In other words, the distance measuring device 30 has a redundant configuration that allows the same area to be measured using emitted light LL1 and LL2. Therefore, even if the windshield FG of the distance measuring device 30 is partially soiled, accurate distance measurement is still possible. Specifically, even if the area through which either emitted light LL1 or LL2 passes is soiled, accurate distance measurement is still possible by using the emitted light from the other source.

[0085] Furthermore, the distance measuring device 30 has an open end 31E that conforms to the inner surface IS of the windshield FG. This makes it possible to compactly install the distance measuring device, for example, on the dashboard and in close contact with or very close to the windshield FG. The distance measuring device may also be partially or completely embedded in the dashboard, i.e., it may be embedded 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 sealing material may be filled into that portion.

[0087] [Controller Configuration] Figure 10 shows the configuration of the controller 40, which is responsible for controlling the light emission of the laser emission receiver 33 of the distance measuring device 30 and for the distance measuring function. The controller 40 may be provided separately from the laser emission receiver 33 and be connected to the laser emission receiver 33 for communication purposes. Alternatively, the controller 40 may be provided within the laser emission receiver 33. In the following description, the case in which the controller 40 is provided separately from the laser emission receiver 33 will be described as an example.

[0088] Furthermore, the controller 40 may be connected to the wiper drive unit WPA that drives the wiper WP in a communicative manner. Specifically, the wiper device may be driven by a signal from the controller 40. Also, the controller 40 may be able to detect whether or not 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 via a system bus 41, for example.

[0090] The large-capacity storage device 43 is composed of, for example, a hard disk drive, an SSD (solid state drive), flash memory, etc., and stores various programs such as the operating system and terminal software. These programs may be obtained, for example, from other server devices via a network, or they 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 and receiving device 33 and for performing distance measurement, as described later) 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 composed of 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 mass storage device 43 to realize various functions.

[0093] The input / output unit 47 is a functional part that communicates information with the laser emission / receiving device 33. The input / output unit 47 can transmit control signals to the laser emission / receiving device 33 to control the operation of the laser emission / receiving device 33. In addition, the input / output unit 47 can receive a reception signal from the laser emission / receiving device 33, which is a signal that occurs when the laser emission / receiving device 33 receives reflected light.

[0094] The control unit 45 can calculate the distance between the object reflecting the irradiated light LL1 and LL2 and the distance measuring device 30 or the automobile M based on the received signal. For example, the control unit 45 can calculate this distance using the TOF (Time of Flight) method or the phase difference method.

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

[0096] Furthermore, the input / output unit 47 may be able to communicate with the wiper drive unit WPA, which is the drive unit of the wiper WP as a removal device. For example, when the control unit 45 detects the presence of foreign matter on the outer surface OS of the windshield FG, it may generate a control signal to cause the removal device to perform a removal operation for the foreign matter, and transmit the control signal to the wiper drive unit WPA via the input / output unit 47.

[0097] Detection of foreign objects on the outer surface OS of the windshield FG may be performed based on a received signal, which is a signal obtained when the laser emission / receiving device 33 receives reflected light. For example, if distance measurement processing is performed based on the received signal and an object close at a distance greater than a threshold is detected, it may be determined that a foreign object is present on the outer surface OS of the windshield FG.

[0098] [Distance measurement operation control routine] The following describes the distance measurement operation control routine executed in the control unit 45 to achieve redundant and accurate distance measurement operation of the distance measuring device 30 in Example 1.

[0099] Figure 11 is a flowchart of an operation control routine R2, which is an example of a distance measurement operation control routine. For example, operation control routine R2 is started when power is supplied to the distance measuring device 30 and is executed repeatedly. Operation control routine R2 may also be started when the ACC power of the vehicle on 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 illumination light LL1 and LL2. If the wiper WP operates while distance measurement is being performed using both illumination light LL1 and LL2, the distance measurement using the illumination light that passes through the area where the wiper WP is passing is stopped. In other words, distance measurement continues using only the illumination light that does not have the wiper WP in 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 for the vehicle M. This determination may be made, for example, by determining whether or not the vehicle M is in an automatic driving state. Specifically, the control unit 45 may obtain information on whether the vehicle M is currently under automatic driving control or manual driving control, and determine that a distance measurement operation is required if it is under automatic driving control.

[0102] Furthermore, the determination of whether or not a range measurement operation is required may be made by determining whether or not the occupant of the vehicle M has initiated the range measurement operation. Alternatively, the determination of whether or not a range measurement operation is required may be made based on the vehicle M's speed or its current position.

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

[0104] After step S22 is completed, in step S23, the control unit 45 determines whether or not a distance measurement operation is required again in the vehicle M. This determination may be made in the same way as the determination in step S21. If it is determined in step S23 that a distance measurement operation is not required (step S23: NO), the control unit 45 instructs the laser emission / receiving device 33 to stop emitting the emitted light EL1 and EL2, and the distance measurement operation ends (step S24). After step S24 is completed, the operation control routine R1 is executed again from the beginning.

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

[0106] As mentioned above, the wiper drive unit WPA and the controller 40 are connected in a communicative manner, so it is also possible to determine whether or not the wiper WP is operating based on the signal from the wiper drive 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 that includes the area through which the wiper is passing, and switches to wiper scanning mode, which is a mode in which distance is measured using only the irradiation light that does not have any foreign objects in its path (step S26).

[0109] In this wiper scanning mode, the laser emission / receiving device 33 may emit only either the emission light EL1 or EL2 depending on the current position of the wiper WP. That is, of the illumination lights LL1 and LL2, only the emission light used for distance measurement may be emitted to the laser emission / receiving device 33. Alternatively, in the wiper scanning mode, both emission lights EL1 and EL2 may be emitted to the laser emission / receiving device 33, and only the reflected light of the illumination lights LL1 and LL2 that do not have a wiper WP in their path may be used for distance measurement.

[0110] After step S26 is executed, in step S27, the control unit 45 determines whether or not a distance measurement operation is required again in the vehicle M. This determination may be made in the same way as the determination in step S21. If it is determined in step S27 that a distance measurement operation is not required (step S27: NO), the control unit 45 instructs the laser emission / receiving device 33 to stop emitting the emitted light EL1 and EL2, and the distance measurement operation ends (step S24). After the completion of step S24, the operation control routine R2 is executed again from the beginning.

[0111] If it is determined in step S27 that a 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 may 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 using the wiper scanning mode is continued.

[0113] In step S28, if it is determined that the wiper WP has stopped operating (step S28: NO), the control unit 45 returns to the normal scanning mode, which uses both the illuminating light LL1 and LL2 for distance measurement, and continues the distance measurement (step S29).

[0114] As described above, the distance measuring device 30 has a configuration in which the irradiated light LL1 and LL2 travel through different paths from the distance measuring device 30, specifically passing through different parts of the windshield FG, and irradiating substantially the same area outside the distance measuring device 30. In other words, the distance measuring device 30 has a redundant configuration that allows the same area to be measured using the irradiated light LL1 and LL2.

[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 wiper WP is operating in the automobile M. Specifically, even if the wiper WP is present in the area through which either the irradiated light LL1 or LL2 passes, accurate distance measurement can be continued by using the irradiated light of the other.

[0116] In the above explanation, the case in which the windshield FG and the deflection plate 35 are formed separately was used as an example, but the deflection plate 35 may be formed integrally with the windshield FG. For example, as shown in Figure 12, by integrally manufacturing the deflection sections 35A and 35B within the windshield FG, it becomes possible to omit the deflection plate 37.

[0117] Furthermore, the control unit 45 of the distance measuring device 30 in Example 2 may execute a routine similar to the operation control routine R1 in Example 1. In that case, for example, the wiper WP may be operated after step S15 to actively remove foreign matter.

[0118] [Differentiation] In the above embodiment, the case described was one in which the deflection sections 17A, 17B, 35A, and 35B can deflect the emitted light EL1 and EL2 in a fixed direction. However, any or both of the deflection sections 17A and 17B, or any or both of the deflection sections 35A and 35B, may be variable deflection sections having the function of deflecting the emitted light EL1 and EL2 in a variable direction. For example, the variable deflection section may consist of a liquid crystal alignment control element.

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

[0120] For example, in Embodiment 1, by making the deflection unit 17B a variable deflection unit, the emitted light EL2 may be deflected in the width direction, i.e., the Y direction, according to the road conditions, so that the emitted light LL2 is irradiated to a different region than the emitted light LL1. For example, when operating as in the operation control routine R1 described above, in the normal scanning mode, when the emitted lights LL1 and LL2 are in a redundant state where they can be used for distance measurement without problems, the deflection direction of the emitted light LL2 may be changed to enable distance measurement in multiple regions.

[0121] The determination of whether to illuminate different areas with illumination light LL1 and illumination light LL2 may be made, for example, based on the conditions in front of the vehicle M, which may be prepared in advance or obtained by the distance measuring devices 10 and 30. The determination of whether to illuminate different areas with illumination light LL1 and illumination light LL2 may also be made, for example, based on map data.

[0122] In the above-described embodiment, the case in which the emitted light EL1 and EL2 are deflected by deflection sections 17A, 17B, 35A, and 35B, which function as transmissive deflection elements, was explained. However, the emitted light EL1 and EL2 may also be deflected by a deflection section that functions as a reflective deflection element and irradiated as the irradiated light LL1 and irradiated light LL2.

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

[0124] 10 Ranging device 11, 31 cabinets 11C,31C opening 13, 33 Laser emission and receiving 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 section that emits light, A light receiving unit that receives the 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 and has an opening end that forms an opening provided on the optical path of the emitted light, A deflection plate having a deflection section that deflects the emitted light, It has, The light emitting unit emits a first light in a first direction and a second light in a second direction. The deflection unit has a first deflection unit that deflects the first emitted light, A distance measuring device characterized in that a first illumination region irradiated with the first emitted light deflected by the first deflection unit and a second illumination region irradiated with the second emitted light overlap each other in at least a portion.

2. The distance measuring device according to claim 1, characterized in that the housing is formed along the inner surface of the light-transmitting member of the moving body.

3. The distance measuring device according to claim 2, characterized in that when the housing is placed on the moving body, the opening is covered by the light-transmitting member of the moving body, and the light-transmitting member and the deflection plate are integrally formed.

4. The distance measuring device according to claim 1, characterized in that the deflection plate covers the opening at the opening end.

5. It has a second deflection part that deflects the second emitted light, The distance measuring device according to any one of claims 1 to 4, characterized in that the second irradiation area is an area irradiated by the second emitted light that has passed through the second deflection section.

6. The distance measuring device according to claim 5, characterized in that it includes a holding member for holding the first deflection portion or the second deflection portion.

7. The distance measuring device according to any one of claims 1 to 6, characterized in that, if an obstacle exists in 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.

8. The distance measuring device according to any one of claims 1 to 7, characterized in that it has a removal means for removing obstacles in the optical paths of the first emitted light and the second emitted light.

9. The light receiving unit receives the first emitted light and the second emitted light reflected by the distance measuring object, The distance measuring device according to any one of claims 1 to 8, characterized in that the light emitting unit changes the emission mode of the first emitted light and the second emitted light according to the light reception results of the reflected first emitted light and the second emitted light.

10. The light-emitting unit has a laser light source that emits the first emitted light and the second emitted light. The distance measuring device according to any one of claims 1 to 9, characterized in that the light emitting unit emits light in a manner that scans the first emitted light in the first direction and emits light in a manner that scans the second emitted light in the second direction.

11. The distance measuring device according to any one of claims 1 to 10, characterized in that the first deflection unit is capable of deflecting the first emitted light in a directionally variable manner.

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