Laser radar device

Abstract

To provide a laser radar device capable of accurately detecting a deposit.SOLUTION: A laser radar device includes a transmission unit 30 in which a plurality of transmission arrays 31 are arranged side by side, a reception unit 40 in which a plurality of reception arrays 41 are arranged side by side, a housing 10 having an irradiation window 11 through which a transmission wave and a reflected wave are transmitted, a light projection and reception control unit 50 that controls operations of the transmission unit and the reception unit, a signal processing unit 60 that outputs a reception signal, and an attached matter determination unit 80 that determines whether or not an attached matter is attached to the irradiation window. The light projection / reception control part can be switched between a normal mode for detecting an object and an extraneous matter detection mode for detecting extraneous matter, and includes a phase control part 51 for changing transmission intensity by controlling a phase of a transmission wave and changing reception sensitivity by controlling a phase of a reflected wave. In the extraneous-matter detecting mode, the phase controller reduces at least one of the transmission intensity and the reception sensitivity so as to make the detection distance smaller than that in the normal mode.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a laser radar device. [Background technology]

[0002] Conventionally, there is known an object recognition device that recognizes an object in front of a vehicle by emitting a transmission wave in front of the vehicle and detecting the reflected wave (see, for example, Patent Document 1). This object recognition device detects an attachment that may cause a decrease in recognition ability by determining that dirt or the like is attached to the transmitting and receiving surface of the laser light if the time from emitting the transmission wave to receiving the reflected wave is shorter than a predetermined measurement time and the intensity of the reflected wave is equal to or greater than a predetermined intensity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-010094 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the determination method described in Patent Document 1, if an object in the vicinity ahead of the vehicle has a high reflectivity, it is difficult to distinguish between a wave reflected from the object and a wave reflected from an attachment attached to the transmitting / receiving surface. For this reason, if the determination method described in Patent Document 1 is used in a laser radar device that detects objects, there is a risk that an object present in the vicinity of the laser radar device will be mistakenly determined to be an attachment attached to the transmitting / receiving surface, making it difficult to accurately detect the attachment. This fact was discovered through extensive research by the inventors.

[0005] In view of the above, an object of the present disclosure is to provide a laser radar device that can detect attached matter with high accuracy. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, A laser radar device for detecting an object a transmitting section (30) in which a plurality of transmitting arrays (31) for transmitting transmission waves are arranged side by side in a first direction; a receiving section (40) in which a plurality of receiving arrays (41) for receiving reflected waves are arranged side by side in a second direction; a housing (10) that houses a transmitting unit and a receiving unit and has an irradiation window (11) that transmits transmitted waves and reflected waves; a light emitting / receiving control unit (50) for controlling the operation of the transmitting unit and the receiving unit; a signal processing unit (60) that outputs a reception signal according to the intensity of the reflected wave received by the receiving unit; an adhering matter determination unit (80) that determines whether or not an adhering matter is adhering to the irradiation window based on the received signal, The light emission and reception control unit is capable of switching the operation modes of the transmission unit and the reception unit between a normal mode for detecting an object and an object detection mode for detecting an object adhering to the irradiation window, and has a phase control unit (51) that changes the transmission intensity of the transmission wave when transmitted by the transmission unit by controlling the phase of each of the transmission waves transmitted by the multiple transmission arrays, and changes the reception sensitivity when the reception unit receives the reflected wave by controlling the phase of each of the reflected waves received by the multiple reception arrays; In the object detection mode, the phase control unit reduces at least one of the transmission intensity and the reception sensitivity, thereby making the detection distance, at which an object can be detected, shorter than the detection distance in the normal mode.

[0007] By making the detection distance in the object detection mode shorter than the detection distance in the normal mode, it becomes difficult to detect an object located farther from the irradiation window in the object detection mode. Therefore, in the object detection mode, it is possible to suppress erroneous determination of an object as an object, and therefore it is possible to detect an object with high accuracy.

[0008] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a laser radar device according to a first embodiment. [Figure 2] FIG. 2 is an explanatory diagram for explaining a light projecting unit according to the first embodiment. [Figure 3] FIG. 2 is an explanatory diagram for explaining a light receiving section according to the first embodiment. [Figure 4] 10A and 10B are diagrams illustrating an example of a light projection range, a light projection distance, a light reception range, and a light reception distance when the diameter of a light projection beam and the diameter of a light reception beam are small. [Figure 5] 10A and 10B are diagrams illustrating an example of a light projection range, a light projection distance, a light receiving range, and a light receiving distance when the diameter of a light projecting beam and the diameter of a light receiving beam are large. [Figure 6] 10A and 10B are explanatory diagrams for explaining the light projection intensity and light receiving sensitivity for each azimuth direction that change depending on the diameter of the light projection beam and the diameter of the light receiving beam. [Figure 7] 10A and 10B are explanatory diagrams for explaining the relationship between the light projection phase and the diameter of the light projection beam, and the relationship between the light reception phase and the diameter of the light reception beam. [Figure 8] 4 is a flowchart showing a control process executed by the laser radar device according to the first embodiment in an object detection mode. [Figure 9] FIG. 10 is an explanatory diagram for explaining the operation of the laser radar device according to the second embodiment. [Figure 10] 10 is a flowchart showing a control process executed by the laser radar device according to the second embodiment in an object detection mode. [Figure 11] FIG. 10 is an explanatory diagram for explaining the operation of the laser radar device according to the third embodiment. [Figure 12] 10 is a flowchart showing a control process executed by a laser radar device according to a third embodiment in an object detection mode. [Figure 13]10A and 10B are explanatory diagrams for explaining changes in the light projection phase difference and changes in the light reception phase difference in an object detection mode executed by the laser radar device according to the third embodiment. [Figure 14] 10A and 10B are explanatory diagrams for explaining how the light projection intensity and light receiving sensitivity change as the light projection phase difference and the light receiving phase difference change. [Figure 15] 10 is a flowchart showing a position detection process executed by a laser radar device according to a third embodiment. [Figure 16] 10 is a flowchart showing a control process executed by a laser radar device according to a fourth embodiment in an object detection mode. [Figure 17] FIG. 10 is an explanatory diagram for explaining the operation of the laser radar device according to the fourth embodiment. [Figure 18] 10 is a flowchart showing a candidate position detection process executed by a laser radar device according to a fourth embodiment. [Figure 19] 10 is a flowchart showing a position identification process executed by a laser radar device according to a fourth embodiment. [Figure 20] FIG. 2 is a diagram illustrating an example of a processed signal output by the laser radar device. [Figure 21] 10 is a flowchart showing a position identification process executed by a laser radar device according to a fifth embodiment. [Figure 22] 13 is a flowchart showing a control process executed by a laser radar device according to a sixth embodiment in an object detection mode. [Figure 23] FIG. 10 is an explanatory diagram for explaining the operation of the laser radar device according to the sixth embodiment. [Figure 24] FIG. 10 is an explanatory diagram for explaining a detection range when the irradiation window is viewed from the front of the irradiation window. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, even if not specifically stated, as long as there is no particular problem with the combination.

[0011] (First embodiment) This embodiment will be described with reference to Figs. 1 to 8. In this embodiment, an example will be described in which a laser radar device 1 according to the present disclosure is applied to a vehicle. As shown in Fig. 1, the laser radar device 1 is a device that transmits a transmission wave toward an object T, such as another vehicle or a stationary object present in the vicinity of the vehicle, and receives a reflected wave reflected by the object T, thereby acquiring information about the object T, such as the distance to the object T, the position of the object T, and the shape of the object T. Hereinafter, a vehicle equipped with the laser radar device 1 according to this embodiment will be referred to as the host vehicle.

[0012] The laser radar device 1 of this embodiment is called a LiDAR (Light Detection and Ranging) device that emits light as a transmission wave and receives reflected light as a reception wave, and is used for driving assistance. The laser radar device 1 is used to measure the distance and relative speed between the vehicle and a preceding vehicle, for example, to perform adaptive cruise control (i.e., ACC) or an automatic braking system.

[0013] The laser radar device 1 is attached, for example, to the inside of the bumper on the front side in the traveling direction of the host vehicle. The laser radar device 1 transmits irradiated light toward the front of the host vehicle and receives light reflected by an object T located in front of the host vehicle, thereby acquiring information about the object T present around the host vehicle.

[0014] The laser radar device 1 can use a TOF (Time of Flight) method to determine the distance and position of the object T. Alternatively, the laser radar device 1 may use an FMCW (Frequency Modulated Continuous Wave) method or an FCM (Modulation Chirp-Fast) method to determine the distance and position of the object T.

[0015] In this case, the laser radar device 1 is configured to transmit irradiated light toward the space outside the vehicle and receive reflected light in a frequency band corresponding to the irradiated light. That is, the laser radar device 1 irradiates irradiated light within a predetermined frequency band toward the external space and receives reflected light within the frequency band from the external space. Note that the frequency band of the radiated light transmitted by the laser radar device 1 is not limited to a frequency band corresponding to millimeter waves, and may be a frequency band other than millimeter waves. In this embodiment, an example will be described in which the laser radar device 1 is configured as a LiDAR that irradiates irradiated light in the millimeter wave band.

[0016] As shown in FIG. 1 , the laser radar device 1 includes a housing 10, a light source 20, a light projecting unit 30, a light receiving unit 40, a light projecting / receiving control unit 50, a signal processing unit 60, a distance measurement calculation unit 70, and an object detection unit 80. The housing 10 is a case that houses the light source 20, the light projecting unit 30, the light receiving unit 40, the light projecting / receiving control unit 50, the signal processing unit 60, the distance measurement calculation unit 70, and the object detection unit 80. The housing 10 includes an emission window 11 that transmits emitted light and reflected light. The emission window 11 is made of a translucent material, such as a transparent resin panel or glass. The light source 20 is an optical device that emits laser light. For example, a semiconductor laser diode can be used as the light source 20.

[0017] The light projecting unit 30 is a transmitting antenna that functions as a transmitter that projects light. The light projecting unit 30 is configured with an optical phased array antenna having multiple transmitting arrays 31 shown in FIG. 2 and optical waveguides (not shown) to which the multiple transmitting arrays 31 are connected. In the light projecting unit 30, each of the multiple transmitting arrays 31 projects light. For example, 12 of the multiple transmitting arrays 31 are arranged in a line along the X direction D1, which is a predetermined direction.

[0018] The multiple transmitting arrays 31 are arranged in the X direction D1 at intervals of half the wavelength of the transmitting wave, i.e., 0.5λ. In FIG. 2, only one representative transmitting array 31 among the multiple transmitting arrays 31 is labeled with a reference numeral, and the other reference numerals are omitted. The number of transmitting arrays 31 is not limited to the above, and the number arranged in the X direction D1 may be a number other than 12 and can be changed as appropriate. Furthermore, the light projecting unit 30 may be arranged in a two-dimensional matrix shape, with multiple transmitting arrays 31 arranged in the X direction D1 as well as in a direction perpendicular to the X direction D1. The X direction D1 corresponds to a first direction in which the transmitting arrays 31 are arranged.

[0019] The light-projecting unit 30 emits illumination light in a direction intersecting the direction in which the multiple transmitting arrays 31 are arranged. For example, as shown in FIG. 2, when the multiple transmitting arrays 31 are arranged in an X direction D1, the illumination light is emitted in a Y direction D2 perpendicular to the X direction D1 or in a Z direction D3 perpendicular to the X direction D1 and the Y direction D2. The light-projecting unit 30 can adjust the direction and beam diameter of the illumination light emitted by the light-projecting unit 30 according to the phase difference between the lights emitted by the multiple transmitting arrays 31. The light-projecting unit 30 can adjust the projection intensity of the illumination light and the distance of the illumination light by changing the beam diameter of the illumination light. The projection intensity corresponds to the transmission intensity of the transmission wave, which is the illumination light. Note that in FIG. 4 and other figures, for ease of understanding, the light-projecting unit 30 and the light-receiving unit 40 are shown as a single unit called a light-projecting and receiving unit 90, and components other than the light-projecting and receiving unit 90 are omitted.

[0020] 4 and other figures, the transmission direction of the light emitted by the light-projecting unit 30 is referred to as the light-projection beam angle θ1, the beam diameter of the light emitted by the light-projecting unit 30 is referred to as the light-projection beam diameter φ1, and the distance of the light emitted by the light-projecting unit 30 is referred to as the light-projection distance L1. The light-projection distance L1 becomes shorter as the light-projection beam diameter φ1 is adjusted to be larger depending on the phase difference between the lights emitted by each of the multiple transmitting arrays 31, and becomes longer as the light-projection beam diameter φ1 is adjusted to be smaller.

[0021] The light receiving unit 40 is a receiving antenna that functions as a receiver that receives light that is emitted from the light projecting unit 30 and reflected by the object T. The light receiving unit 40 is composed of an optical phased array antenna having multiple receiving arrays 41 shown in FIG. 3 and an optical waveguide (not shown) to which the multiple receiving arrays 41 are connected. In the light receiving unit 40, each of the multiple receiving arrays 41 receives reflected light. The multiple receiving arrays 41 have, for example, the same configuration as the receiving array 41. Specifically, as shown in FIG. 3, the multiple receiving arrays 41 of this embodiment are arranged in a row of 12 along the X direction D1.

[0022] The multiple receiving arrays 41 are arranged in the X direction D1 at intervals of half the wavelength of the transmission wave, i.e., 0.5λ. In FIG. 3, only one representative receiving array 41 among the multiple receiving arrays 41 is labeled with a reference numeral, and the other reference numerals are omitted. The configuration of the receiving array 41 is not limited to the above and may be different from that of the transmitting array 31 and can be modified as appropriate. That is, the number of receiving arrays 41 arranged in the X direction D1 may be different from 12. Furthermore, the light receiving unit 40 may be arranged in a two-dimensional matrix, with multiple receiving arrays 41 arranged in the X direction D1 as well as in a direction perpendicular to the X direction D1. The X direction D1 corresponds to the second direction in which the receiving arrays 41 are arranged.

[0023] The light receiving unit 40 receives reflected light from a direction intersecting the direction in which the multiple receiving arrays 41 are arranged. For example, when the multiple receiving arrays 41 are arranged in the X direction D1, the light receiving unit 40 receives reflected light from the Y direction D2, which is perpendicular to the X direction D1, or the Z direction D3, which is perpendicular to the X direction D1 and the Y direction D2. The light receiving unit 40 can adjust the direction and beam diameter of the reflected light received according to the phase difference between the light received by each of the multiple receiving arrays 41. The light receiving unit 40 can adjust the light receiving range R2 and the distance over which the reflected light can be received by changing the beam diameter of the reflected light received.

[0024] Hereinafter, as shown in Figure 4 etc., the receiving direction of reflected light received by the light receiving unit 40 may be referred to as the received light beam angle θ2, the beam diameter of the reflected light may be referred to as the received light beam diameter φ2, and the distance over which the reflected light can be received may be referred to as the light receiving distance L2. The light receiving distance L2 becomes shorter as the received light beam diameter φ2 is adjusted to be larger depending on the phase difference of the light received by each of the multiple receiving arrays 41, and becomes longer as the received light beam diameter φ2 is adjusted to be smaller. The light receiving unit 40 outputs a light receiving signal to the signal processing unit 60 according to the intensity of the reflected light received by each receiving array 41.

[0025] The light projecting / receiving control unit 50 controls the operation of the light projecting unit 30 and the light receiving unit 40. As will be described later, the light projecting / receiving control unit 50 can switch the operation mode of the light projecting unit 30 and the light receiving unit 40 between a normal mode for detecting an object T and an object detection mode for detecting an object A adhering to the irradiation window 11.

[0026] 1, the light projecting and receiving control unit 50 also has a phase control unit 51. The phase control unit 51 includes a phase shifter that adjusts the phase of light emitted by each of the multiple transmitting arrays 31 of the light projecting unit 30 and the phase of light received by each of the multiple receiving arrays 41 of the light receiving unit 40. The phase control unit 51 includes a control circuit that shifts the light projecting phase, which is the phase of light emitted by each of the transmitting arrays 31, and shifts the light receiving phase, which is the phase of light received by each of the receiving arrays 41.

[0027] The phase control unit 51 adjusts the light projection phase to electronically control the light projection beam angle θ1, light projection beam diameter φ1, light projection distance L1, and light projection intensity. The phase control unit 51 also adjusts the light reception phase to electronically control the light reception beam angle θ2, light reception beam diameter φ2, light reception distance L2, and light reception sensitivity. The light projection phase and light reception phase adjusted by the phase control unit 51 will be described in detail later.

[0028] The signal processing unit 60 is a signal processing circuit that performs signal processing such as amplification, FFT, and filtering on the light-receiving signal received from the light-receiving unit 40. The signal processing unit 60 and the distance measurement calculation unit 70 and object-detection unit 80 described below may be implemented by a microcomputer equipped with a CPU, nonvolatile memory such as flash memory, and volatile memory such as RAM. In this case, the signal processing unit 60, distance measurement calculation unit 70, and object-detection unit 80 perform various processes described below by the CPU executing programs stored in the nonvolatile memory and using the volatile memory as a working area. Alternatively, the signal processing unit 60, distance measurement calculation unit 70, and object-detection unit 80 may be dedicated circuits configured to perform various processes described below. The signal processing unit 60 performs various signal processing on the light-receiving signal and outputs processed signals to the distance measurement calculation unit 70 and object-detection unit 80. The processed signals correspond to received signals corresponding to the intensity of reflected light received by the light-receiving unit 40.

[0029] The distance measurement calculation unit 70 calculates the distance to the object T, the speed of the object T, etc. based on the processed signal acquired from the signal processing unit 60. The distance measurement calculation unit 70 calculates the distance to the object T, the speed of the object T, etc. based on the difference between the frequency of the light emitted by the light projecting unit 30 and the frequency of the reflected light received by the light receiving unit 40, for example, by the FMCW method.

[0030] The object determining unit 80 determines whether or not an object A is attached to the irradiation window 11 based on the processed signal obtained from the signal processing unit 60. The processed signal is a signal obtained by performing various signal processing on a light receiving signal corresponding to the intensity of reflected light. Therefore, the object determining unit 80 determines whether or not an object A is attached to the irradiation window 11 based on the intensity of reflected light. A specific determination method will be described later.

[0031] Next, the reason why the phase control unit 51 controls the light projection phase and the light reception phase will be described with reference to Figures 4 to 7. The phase control unit 51 controls the light projection phase of multiple transmitting arrays 31 lined up along the X direction D1, thereby adjusting the light projection beam angle θ1, the light projection beam diameter φ1, and the light projection distance L1. Furthermore, the phase control unit 51 controls the light reception phase of multiple receiving arrays 41 lined up along the X direction D1, thereby controlling the light reception beam angle θ2, the light reception beam diameter φ2, and the light reception distance L2.

[0032] Here, the dashed lines in Fig. 4 indicate the projection range R1 of the irradiated light when the projection beam diameter φ1 is set to be small, and the light receiving range R2 when the reception beam diameter φ2 is set to be small. The dashed lines in Fig. 5 indicate the projection range R1 of the irradiated light when the projection beam diameter φ1 is set to be large, and the light receiving range R2 when the reception beam diameter φ2 is set to be large. The projection range R1 is based on the projection beam diameter φ1, projection beam angle θ1, and projection distance L1. The reception range R2 is based on the reception beam diameter φ2, reception beam angle θ2, and reception distance L2.

[0033] 4 and 5 indicate the projected beam diameter φ1, the received beam diameter φ2, the projected beam angle θ1, and the received beam angle θ2. The projected beam angle θ1 is the angle formed by a line passing through the center of the projected beam diameter φ1 and a line along the Z direction D3. The received beam angle θ2 is the angle formed by a line passing through the center of the received beam diameter φ2 and a line along the Z direction D3.

[0034] The dashed lines in Fig. 4 show the light projection intensity when the light projection phase is controlled so that the light projection beam diameter φ1 is reduced, and the light receiving sensitivity when the light receiving phase is controlled so that the light receiving beam diameter φ2 is reduced. The dashed lines in Fig. 5 show the light projection intensity when the light projection phase is controlled so that the light projection beam diameter φ1 is increased, and the light receiving sensitivity when the light receiving phase is controlled so that the light receiving beam diameter φ2 is increased. The receiving sensitivity is the receiving sensitivity when the light receiving unit 40 receives a reflected wave, which is reflected light.

[0035] If the light projection phase is controlled so that the light projection beam diameter φ1 becomes smaller, the light projection intensity in a predetermined direction becomes larger, and the light projection intensity in directions other than the predetermined direction becomes significantly smaller than the light projection intensity in the predetermined direction, as shown by the solid line in Fig. 6. In contrast, if the light projection phase is controlled so that the light projection beam diameter φ1 becomes larger, the light projection intensity in all irradiated directions becomes roughly equal, and the difference in light projection intensity between directions becomes smaller, as shown by the dashed line in Fig. 6.

[0036] In other words, when the light projection phase is controlled so that the light projection beam diameter φ1 becomes smaller, the light projection distance L1 at a predetermined light projection beam angle θ1 becomes longer and the light projection intensity becomes greater. On the other hand, the light projection distance L1 in directions other than the predetermined light projection beam angle θ1 becomes shorter and the light projection intensity becomes smaller.

[0037] Furthermore, if the light projection phase is controlled so that the light projection beam diameter φ1 increases, the light projection beam angle θ1 will not be fixed in a predetermined direction, the light projection distance L1 in all directions will become shorter, and the light projection intensity will become smaller. Therefore, if the light projection phase is controlled so that the light projection beam diameter φ1 increases, the ranging distance, which is the detectable distance when the laser radar device 1 detects the distance to the object T, will be limited, and the detection accuracy when the laser radar device 1 detects the speed of the object T will decrease.

[0038] Furthermore, when the light-receiving phase is controlled so that the light-receiving beam diameter φ2 is reduced, the light-receiving sensitivity in a predetermined direction increases, and the light-receiving sensitivity in directions other than the predetermined direction becomes significantly smaller than the light-receiving sensitivity in the predetermined direction, as shown by the solid line in Fig. 6. In contrast, when the light-receiving phase is controlled so that the light-receiving beam diameter φ2 increases, the light-receiving sensitivity in all directions in which reflected light is received becomes roughly equal, and the difference in light-receiving sensitivity between directions becomes smaller, as shown by the dashed line in Fig. 6.

[0039] In other words, when the light-receiving phase is controlled so that the light-receiving beam diameter φ2 becomes smaller, the light-receiving distance L2 at a predetermined light-receiving beam angle θ2 becomes longer and the light-receiving sensitivity becomes higher. On the other hand, the light-receiving distance L2 in directions other than the predetermined light-receiving beam angle θ2 becomes shorter and the light-receiving sensitivity becomes lower.

[0040] Furthermore, if the light-receiving phase is controlled so that the light-receiving beam diameter φ2 increases, the light-receiving beam angle θ2 will not be fixed in a predetermined direction, the light-receiving distance L2 in all directions will be shorter, and the light-receiving sensitivity will be reduced. Therefore, if the light-receiving phase is controlled so that the light-receiving beam diameter φ2 increases, the ranging distance when the laser radar device 1 detects the distance to the object T will be limited, and the detection accuracy when the laser radar device 1 detects the speed of the object T will be reduced.

[0041] Therefore, in order to improve the accuracy of detecting the speed while ensuring the detectable distance of the laser radar device 1, it is desirable that the phase control unit 51 controls the light projection phase so as to reduce the light projection beam diameter φ1 and the light reception phase so as to reduce the light reception beam diameter φ2. It is also desirable to detect an object T ahead of the vehicle by changing the light projection beam angle θ1 and the light reception beam angle θ2 while maintaining the light projection beam diameter φ1 and the light reception beam diameter φ2 in a small state.

[0042] Here, the relationship between the light projection phase and the light projection beam diameter φ1 and the relationship between the light reception phase and the light reception beam diameter φ2 will be described with reference to FIG.

[0043] In the multiple transmitting arrays 31 arranged along the X direction D1, the difference in the light projection phase between adjacent transmitting arrays 31 is assumed to be equal, as shown by the solid line in FIG. 7. In this case, the light projection beam diameter φ1 can be reduced, as shown by the solid line in FIG. 4. In other words, as shown in the graph in FIG. 7, when an imaginary line passing through the light projection phase values ​​of adjacent transmitting arrays 31 is linear, the light projection beam diameter φ1 can be reduced. Here, the direction in which the multiple transmitting arrays 31 are arranged along the X direction D1 is defined as the transmitting array arrangement direction. When the light projection phase value increases or decreases proportionally to the transmitting array arrangement direction, the light projection beam diameter φ1 can be reduced.

[0044] In contrast, suppose that, among the multiple transmitting arrays 31 arranged along the X direction D1, the difference in the light projection phase between adjacent transmitting arrays 31 is unequal, as shown by the dashed line in Fig. 7. In other words, suppose that there is variation in the difference in the light projection phase between the transmitting arrays 31 arranged in the direction in which the transmitting arrays are arranged. In this case, the projected beam diameter φ1 becomes larger, as shown by the dashed line in Fig. 5.

[0045] 7, when the difference between the light projection phases of adjacent transmitting arrays 31 increases and decreases irregularly, causing the virtual line connecting the light projection phase values ​​to be non-linear, the light projection beam diameter φ1 increases. In other words, when the light projection phase values ​​change randomly with respect to the arrangement direction of the transmitting arrays, causing the slope of the virtual line connecting the light projection phase values ​​to change irregularly with respect to the arrangement direction of the transmitting arrays, the light projection beam diameter φ1 increases.

[0046] Furthermore, among the multiple receiving arrays 41 arranged along the X direction D1, the difference in the light receiving phase between adjacent receiving arrays 41 is assumed to be equal, as shown by the solid line in FIG. 7. In this case, the light receiving beam diameter φ2 can be reduced, as shown by the solid line in FIG. 4. As shown in the graph in FIG. 7, if an imaginary line passing through the light receiving phase values ​​of adjacent receiving arrays 41 is linear, the light receiving beam diameter φ2 can be reduced. Here, the direction in which the multiple receiving arrays 41 are arranged along the X direction D1 is referred to as the receiving array arrangement direction. If the light receiving phase value increases or decreases proportionally to the receiving array arrangement direction, the light receiving beam diameter φ2 can be reduced.

[0047] In contrast, suppose that, among the multiple receiving arrays 41 lined up along the X direction D1, the difference in the light receiving phase between adjacent receiving arrays 41 is unequal, as shown by the dashed line in Fig. 7. In other words, suppose that there is variation in the difference in the light receiving phase between the receiving arrays 41 lined up in the receiving array arrangement direction. In this case, the diameter φ2 of the receiving light beam becomes larger, as shown by the dashed line in Fig. 5.

[0048] 7, when the difference between the light receiving phases of adjacent receiving arrays 41 increases or decreases irregularly, causing the imaginary line connecting the light receiving phase values ​​to not be linear, the diameter φ2 of the light receiving beam increases. In other words, when the light receiving phase values ​​change randomly with respect to the arrangement direction of the receiving arrays, causing the slope of the imaginary line connecting the light receiving phase values ​​to change irregularly with respect to the arrangement direction of the receiving arrays, the diameter φ2 of the light receiving beam increases.

[0049] Hereinafter, as shown in FIG. 7, the difference in the light projection phase between adjacent transmitting arrays 31 is referred to as the light projection phase difference Δω1. There is a correlation between the light projection phase difference Δω1 between adjacent transmitting arrays 31 arranged in the X direction D1 and the light projection beam diameter φ1. Specifically, the more constant or close to constant the light projection phase difference Δω1 is, the smaller the light projection beam diameter φ1 can be. In other words, when the difference between the light projection phase differences Δω1 in the arrangement direction of the transmitting arrays is zero or closer to zero, the light projection beam diameter φ1 can be made smaller. Furthermore, when the imaginary line passing through the values ​​of the light projection phases of the transmitting arrays 31 is linear or has a shape close to a straight line, the light projection beam diameter φ1 can be made smaller.

[0050] On the other hand, the greater the variation in the light projection phase difference Δω1 and the more irregularly the light projection phase difference Δω1 changes, the larger the light projection beam diameter φ1. In other words, the greater the difference between adjacent light projection phase differences Δω1, the larger the light projection beam diameter φ1. Furthermore, there is a correlation between the slope of the imaginary line passing through the light projection phase values, the slope of the approximation line for the light projection phase values, and the light projection beam angle θ1. Specifically, the larger the absolute values ​​of the slope of the imaginary line passing through the light projection phase values ​​and the slope of the approximation line for the light projection phase values, the larger the light projection beam angle θ1. Furthermore, the smaller the absolute values ​​of the slope of the imaginary line passing through the light projection phase values ​​and the slope of the approximation line for the light projection phase values, the smaller the light projection beam angle θ1.

[0051] The difference in the light receiving phase between adjacent receiving arrays 41 is defined as the light receiving phase difference Δω2. There is a correlation between the difference in the light receiving phase difference Δω2 between adjacent receiving arrays 41 arranged in the X direction D1 and the light receiving beam diameter φ2. Specifically, the more constant or close to constant the difference in the light receiving phase difference Δω2 is, the smaller the light receiving beam diameter φ2 can be. In other words, when the difference in the light receiving phase difference Δω2 in the arrangement direction of the receiving arrays is zero or close to zero, the light receiving beam diameter φ2 can be made smaller. Furthermore, when the imaginary line passing through the light receiving phase values ​​of the receiving arrays 41 is linear or has a shape close to a straight line, the light receiving beam diameter φ2 can be made smaller.

[0052] On the other hand, the greater the variation in the received light phase difference Δω2 and the more irregularly the difference in the received light phase difference Δω2 changes, the larger the received light beam diameter φ2. In other words, the greater the difference between adjacent received light phase differences Δω2, the larger the received light beam diameter φ2.

[0053] Furthermore, there is a correlation between the slope of the virtual line passing through the received phase value, the slope of the approximation line for the received phase value, and the received beam angle θ2. Specifically, the larger the absolute value of the slope of the virtual line passing through the received phase value and the slope of the approximation line for the received phase value, the larger the received beam angle θ2. And the smaller the absolute value of the slope of the virtual line passing through the received phase value and the slope of the approximation line for the received phase value, the smaller the received beam angle θ2.

[0054] When detecting an object T ahead of the vehicle, the laser radar device 1 desirably controls the light projection phase to reduce the light projection beam diameter φ1 and the light reception phase to reduce the light reception beam diameter φ2, in order to improve the speed detection accuracy while ensuring the distance measurement. The laser radar device 1 desirably scans the area ahead of the vehicle by varying the light projection beam angle θ1 and the light reception beam angle θ2 within a predetermined range while keeping the light projection beam diameter φ1 and the light reception beam diameter φ2 small. Therefore, when detecting an object T, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 and the light reception phases of the multiple receiving arrays 41 so that the difference between the light projection phase difference Δω1 and the light reception phase difference Δω2 approaches a constant value.

[0055] However, there is a possibility that an attachment A as shown in Fig. 1 may adhere to the irradiation window 11 of the housing 10, which may hinder the laser radar device 1 from detecting an object T. For example, if dirt that prevents the transmission of the irradiated light and reflected light adheres to the irradiation window 11, the dirt may prevent the irradiated light and reflected light from passing through the irradiation window 11. Furthermore, if water, snow, or the like adheres to the irradiation window 11, the water or snow may scatter the irradiated light and reflected light.

[0056] Therefore, if an object A adheres to the irradiation window 11, it will cause a decrease in the distance measurement distance and a decrease in detection accuracy. Therefore, the laser radar device 1 of this embodiment is capable of detecting an object A adhered to the irradiation window 11. Specifically, the laser radar device 1 is capable of switching its operation mode between a normal mode for detecting an object T and an object detection mode for detecting an object A adhered to the irradiation window 11.

[0057] The light-projecting and light-receiving control unit 50 of this embodiment executes the normal mode when detecting an object T ahead of the vehicle. In the normal mode, as described above, the phase control unit 51 controls the light-projecting phases of the multiple transmitting arrays 31 and the light-receiving phases of the multiple receiving arrays 41 so that the differences between all the light-projecting phase differences Δω1 and the differences between all the light-receiving phase differences Δω2 approach a constant value. The light-projecting unit 30 then causes each of the multiple transmitting arrays 31 to emit light based on the light-projecting phase set by the phase control unit 51. The light emitted from the light-projecting unit 30 passes through the irradiation window 11 and is irradiated toward the object T present ahead of the host vehicle.

[0058] In the light receiving unit 40, each of the multiple receiving arrays 41 receives reflected light based on the light receiving phase set by the phase control unit 51. When an object T is present ahead of the vehicle, each of the receiving arrays 41 in the light receiving unit 40 receives reflected light reflected by the object T and outputs a light receiving signal corresponding to the intensity of the received reflected light to the signal processing unit 60. The signal processing unit 60 performs various signal processing on the light receiving signal and outputs a processed signal to the distance measurement calculation unit 70.

[0059] The distance measurement calculation unit 70 calculates the distance to the object T, the speed of the object T, etc. based on the difference between the frequency of the light emitted by the light projecting unit 30 and the frequency of the reflected light received by the light receiving unit 40. The distance measurement calculation unit 70 outputs information such as the calculated distance to the object T and the speed of the object T to a vehicle control device (not shown) that controls adaptive cruise control and an automatic braking system.

[0060] Furthermore, the phase control unit 51 keeps all light projection phase differences Δω1 constant while varying the light projection phase difference Δω1 to change the light projection beam angle θ1. Furthermore, while keeping all light reception phase differences Δω2 constant, the phase control unit 51 changes the light reception phase difference Δω2 to change the light reception beam angle θ2. In this way, the laser radar device 1 changes the direction of the light emitted from the light projector 30 and the direction of the reflected light received by the light receiver 40 to scan within a predetermined scanning range.

[0061] As described above, in normal mode, the laser radar device 1 emits light ahead of the vehicle and receives reflected light from the object T present within the scanning range to determine the distance to the object T, the speed of the object T, etc. The information determined by the laser radar device 1, such as the distance to the object T and the speed of the object T, is used for driving the vehicle.

[0062] On the other hand, when detecting an object A adhering to the irradiation window 11, the laser radar device 1 executes the object detection mode by executing the control process shown in Fig. 8. In the object detection mode, as in the normal mode, the light-projecting unit 30 emits irradiation light based on the light-projecting phase set by the phase control unit 51, and the light-receiving unit 40 receives reflected light based on the light-receiving phase set by the phase control unit 51, thereby scanning a predetermined scanning range. However, the light-projecting phase and light-receiving phase set by the phase control unit 51 in the object detection mode are different from those in the normal mode. Also, in the object detection mode, the object determination unit 80 determines whether or not an object A is attached to the irradiation window 11 based on a processed signal obtained from the signal processing unit 60.

[0063] When the object detection mode is executed, the laser radar device 1 repeatedly emits irradiation light from the light projecting unit 30 and outputs a light reception signal to the signal processing unit 60 every time the light receiving unit 40 receives reflected light. In addition, the signal processing unit 60 outputs a processing signal to the object determining unit 80 every time it receives a light reception signal. In addition, the laser radar device 1 executes the control process shown in FIG. 8.

[0064] The laser radar device 1 may repeatedly execute the control process shown in FIG. 8. The laser radar device 1 may alternate between the normal mode and the object detection mode. Alternatively, the laser radar device 1 may execute the object detection mode when the driver performs an operation requesting the object detection mode. The laser radar device 1 may be able to execute the object detection mode while the vehicle is traveling, or may be able to execute the object detection mode while the vehicle is stopped. The object detection mode executed by the laser radar device 1 will be described with reference to FIG. 8.

[0065] First, in step S10, the phase control unit 51 increases the variation in the light-projection phase difference Δω1 compared to the normal mode, thereby increasing the difference between adjacent light-projection phase differences Δω1. Furthermore, the phase control unit 51 increases the variation in the light-reception phase difference Δω2 compared to the normal mode, thereby increasing the difference between adjacent light-reception phase differences Δω2. Specifically, when detecting an attachment A, the phase control unit 51 controls the light-projection phases of the multiple transmitting arrays 31 so that the slope of the virtual line connecting the values ​​of the light-projection phases changes significantly, as shown in FIG. 7. Furthermore, when detecting an attachment A, the phase control unit 51 controls the light-reception phases of the multiple receiving arrays 41 so that the slope of the virtual line connecting the values ​​of the light-reception phases changes significantly.

[0066] As a result, in the object detection mode, the light projection beam diameter φ1 is larger than the light projection beam diameter φ1 in the normal mode, and the light reception beam diameter φ2 is larger than the light reception beam diameter φ2 in the normal mode. As a result, in the object detection mode, the light projection distance L1 is shorter than the light projection distance L1 in the normal mode, and the light projection intensity is smaller than the light projection intensity in the normal mode. Also, in the object detection mode, the light reception distance L2 is shorter than the light reception distance L2 in the normal mode, and the light reception sensitivity is smaller than the light reception sensitivity in the normal mode.

[0067] However, in the object detection mode, the cross-sectional area perpendicular to a line extending along the light projection beam angle θ1 in the light projection range R1 is larger than the cross-sectional area perpendicular to a line extending along the light projection beam angle θ1 in the light projection range R1 in the normal mode. Also, in the adhesion detection mode, the cross-sectional area perpendicular to a line extending along the light reception beam angle θ2 in the light reception range R2 is larger than the cross-sectional area perpendicular to a line extending along the light reception beam angle θ2 in the light reception range R2 in the normal mode.

[0068] In this embodiment, as shown in FIG. 5, the phase control unit 51 controls the light-projecting phases of the multiple transmitting arrays 31 and the light-receiving phases of the multiple receiving arrays 41 so that the light-projecting range R1 and the light-receiving range R2 can cover substantially the entire area of ​​the irradiation window 11. Furthermore, in this embodiment, the phase control unit 51 controls the light-projecting phases of the multiple transmitting arrays 31 so that the light-projecting distance L1 is slightly longer than the distance from the light-projecting unit 30 to the irradiation window 11. Furthermore, the phase control unit 51 controls the light-receiving phases of the multiple receiving arrays 41 so that the light-receiving distance L2 is slightly longer than the distance from the light-receiving unit 40 to the irradiation window 11. As a result, the measuring distance in the object detection mode is shorter than the measuring distance in the normal mode, as shown in FIG. 1. Hereinafter, the overlapping ranges of the light-projecting range R1 and the light-receiving range R2 are referred to as the detection range RA.

[0069] In the light-projecting unit 30, each of the multiple transmitting arrays 31 emits irradiation light toward the irradiation window 11 based on the light-projecting phase set by the phase control unit 51. In addition, in the light-receiving unit 40, each of the multiple receiving arrays 41 receives reflected light based on the light-receiving phase set by the phase control unit 51, and outputs a light-receiving signal corresponding to the intensity of the received reflected light to the signal processing unit 60. The signal processing unit 60 performs various signal processing on the light-receiving signal and outputs a processed signal to the object determination unit 80. When an object A is attached to the irradiation window 11, the light-receiving unit 40 outputs a light-receiving signal corresponding to the intensity of the light reflected from the object A to the signal processing unit 60.

[0070] By controlling the light projection phases of the multiple transmitting arrays 31 and the light reception phases of the multiple receiving arrays 41 in this manner, the laser radar device 1 can receive the light reflected by the object A when the object A is attached to the irradiation window 11. Furthermore, in the object detection mode, the laser radar device 1 has difficulty receiving the light reflected by an object T located farther away than the irradiation window 11.

[0071] Next, in step S11, the object determination unit 80 determines whether the peak of the processed signal received from the signal processing unit 60 is equal to or greater than the determination threshold. If the object determination unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S100. On the other hand, if the object determination unit 80 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S200. The determination threshold is a predetermined threshold value that is set in advance to determine whether or not an object A is attached to the irradiation window 11, and can be obtained, for example, by conducting an experiment in advance in which reflected light is received with an object A attached to the irradiation window 11.

[0072] In step S100, the object determination unit 80 determines that object A is attached to the irradiation window 11, outputs the determination result to the vehicle control device, and ends the object detection mode process. When the vehicle control device receives the determination result indicating that object A is attached to the irradiation window 11 from the laser radar device 1, the vehicle control device performs vehicle control corresponding to the state in which object A is attached to the irradiation window 11. For example, the vehicle control device stops operation of the adaptive cruise control or the automatic braking system. Alternatively, if the vehicle is equipped with a removal device that removes object A attached to the irradiation window 11 using water pressure or the like, the vehicle control device may activate the removal device to remove object A.

[0073] In response to this, in step S200, the object determining unit 80 determines that the object A is not attached to the irradiation window 11, and ends the processing of the object detection mode.

[0074] As described above, the laser radar device 1 of this embodiment includes a light-projecting unit 30 in which a plurality of transmitting arrays 31 that emit irradiated light as a transmission wave are arranged side by side in the X-direction D1. The laser radar device 1 also includes a light-receiving unit 40 in which a plurality of receiving arrays 41 that receive reflected light as a reflected wave are arranged side by side in the X-direction D1. The laser radar device 1 also includes a housing 10 that houses the light-projecting unit 30 and the light-receiving unit 40 and has an irradiation window 11 that transmits the irradiated light and the reflected light, and a light-projecting / light-receiving control unit 50 that controls the operation of the light-projecting unit 30 and the light-receiving unit 40. The laser radar device 1 also includes a signal processing unit 60 that outputs a processed signal corresponding to the intensity of the reflected light received by the light-receiving unit 40, and an object determination unit 80 that determines whether or not an object A is attached to the irradiation window 11 based on the processed signal. The light-emitting / receiving control unit 50 switches the operation modes of the light-emitting unit 30 and the light-receiving unit 40 between a normal mode for detecting an object T and an object detection mode for detecting an object A adhering to the emission window 11. The light-emitting / receiving control unit 50 also has a phase control unit 51 that controls the phase of each of the emitted lights transmitted by the multiple transmitting arrays 31 to change the light-emitting intensity of the emitted light when transmitted by the light-emitting unit 30, and controls the phase of each of the reflected lights received by the multiple receiving arrays 41 to change the light-receiving sensitivity when the light-receiving unit 40 receives the reflected light. By changing the light-emitting intensity and light-receiving sensitivity, the phase control unit 51 makes the detection distance in the object detection mode shorter than the detection distance in the normal mode.

[0075] According to this, by making the detection distance in the object detection mode shorter than the detection distance in the normal mode, it becomes difficult to detect an object T located farther away from the irradiation window 11 in the object detection mode. Therefore, in the object detection mode, it is possible to suppress erroneous determination that the object T is detected as an object A, and therefore it is possible to detect the object A with high accuracy.

[0076] Furthermore, according to the above embodiment, the following effects can be obtained.

[0077] (1) In the above embodiment, the phase control unit 51 increases the variation in the light-projection phase difference Δω1 and the variation in the light-reception phase difference Δω2 in the object detection mode compared to the normal mode, thereby decreasing the detection distance in the object detection mode compared to the detection distance in the normal mode.

[0078] The light projecting unit 30 of this embodiment is configured with an optical phased array antenna having a plurality of transmitting arrays 31 and optical waveguides (not shown) to which the plurality of transmitting arrays 31 are connected. The light projecting unit 30 configured with an optical phased array controls the phase of light emitted by each of the plurality of transmitting arrays 31 to adjust the projection beam angle θ1 and the projection intensity.

[0079] The light receiving unit 40 of this embodiment is configured with an optical phased array antenna having multiple receiving arrays 41 and optical waveguides (not shown) to which the multiple receiving arrays 41 are connected. The light receiving unit 40 configured with an optical phased array controls the phase of the light received by each of the multiple receiving arrays 41 to adjust the receiving beam angle θ2 and the light projection intensity.

[0080] For this reason, when the laser radar device 1 employs the light-projecting unit 30 configured as an optical phased array and the light-receiving unit 40 configured as an optical phased array, a phase control unit 51 is required to control the phase of the emitted light and the reflected light. In this embodiment, the phase control unit 51 controls the variation in the light-projecting phase difference Δω1 and the variation in the light-receiving phase difference Δω2, thereby making it possible to make the detection distance in the object detection mode shorter than the detection distance in the normal mode. Therefore, the laser radar device 1 of this embodiment can adjust the detection distance without providing a separate light source for changing the detection distance or an adjustment mechanism for adjusting the detection distance.

[0081] (Second embodiment) Next, a second embodiment will be described with reference to Figures 9 and 10. In this embodiment, the projected beam diameter φ1 and the received beam diameter φ2 when the object detection mode is executed are different from those in the first embodiment, and part of the processing executed by the laser radar device 1 in the object detection mode is different from that in the first embodiment. Other than this, the second embodiment is the same as the first embodiment. Therefore, in this embodiment, the differences from the first embodiment will be mainly described, and a description of the same parts as in the first embodiment may be omitted.

[0082] 9, the phase control unit 51 of this embodiment reduces the light projection beam diameter φ1 and the light reception beam diameter φ2 when the object detection mode is executed compared to the first embodiment. Specifically, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 and the light reception phases of the multiple receiving arrays 41, respectively, to control the light projection beam diameter φ1 and the light reception beam diameter φ2 so that the light projection range R1 and the light reception range R2 can cover part of the irradiation window 11.

[0083] Furthermore, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 and the light reception phases of the multiple receiving arrays 41 so that the light reception beam diameter φ2 is smaller than the light projection beam diameter φ1. In other words, the phase control unit 51 controls the multiple light projection phases and light reception phases so that the light reception distance L2 at a predetermined light projection beam angle θ1 is longer than the light projection distance L1 at the predetermined light projection beam angle θ1, and so that the light reception sensitivity is greater than the light projection intensity. As a result, in this embodiment, the detection range RA where the light projection range R1 and the light reception range R2 overlap is limited.

[0084] In this embodiment, the light projection phase is controlled so that the light projection distance L1 is slightly longer than the distance from the light projector 30 to the irradiation window 11. In Fig. 9, the dashed dotted line indicates the projection range R1 of the irradiation light, and the dashed two dotted line indicates the light receiving range R2.

[0085] A specific object detection mode executed by the laser radar device 1 of this embodiment will be described with reference to Fig. 10. Note that the processes of steps S11, S100, and S200 shown in Fig. 10 are similar to the processes of steps S11, S100, and S200 shown and described in Fig. 8, and therefore detailed description thereof will be omitted.

[0086] First, in step S10, the phase control unit 51 controls each of the light projection phase and the light reception phase so that the light reception beam diameter φ2 is smaller than the light projection beam diameter φ1 while increasing the variation in the light projection phase difference Δω1 and the variation in the light reception phase difference Δω2 compared to the normal mode. Specifically, the phase control unit 51 controls each of the light projection phases of the multiple transmitting arrays 31 so that the light projection range R1 at a predetermined light projection beam angle θ1 covers a part of the irradiation window 11 and the light projection distance L1 is slightly longer than the distance from the light projector 30 to the irradiation window 11. Then, the phase control unit 51 controls each of the light projection phases of the multiple transmitting arrays 31 so that the light projection range R1 includes the upper end of the irradiation window 11.

[0087] Furthermore, the phase control unit 51 controls the light receiving phases of the multiple receiving arrays 41 so that the light receiving beam angle θ2 is the same as the light projection beam angle θ1 and the light receiving distance L2 is longer than the light projection distance L1. By controlling the light projection phase and the light receiving phase in this manner, when an object A is attached to the irradiation window 11 within the light projection range R1, the laser radar device 1 can receive the light reflected by the object A. Furthermore, in the object detection mode, the laser radar device 1 has difficulty receiving the light reflected by an object T located farther away than the irradiation window 11.

[0088] Then, in step S11, the object-determining unit 80 determines whether the peak of the processed signal received from the signal processing unit 60 is equal to or greater than the determination threshold. Specifically, if the object-determining unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S100. On the other hand, if the object-determining unit 80 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S20.

[0089] In step S20, while maintaining the state in which the light projection phase differences Δω1 vary, the phase control unit 51 changes the magnitude of each of the light projection phase differences Δω1 to change the light projection beam angle θ1 downward, as shown in Fig. 9. Specifically, while maintaining the size of the light projection beam diameter φ1, the phase control unit 51 changes the light projection beam angle θ1 so that part of the changed light projection range R1 overlaps part of the pre-change light projection range R1. Furthermore, while maintaining the state in which the light reception phase differences Δω2 vary, the phase control unit 51 changes the magnitude of each of the light reception phase differences Δω2 to change the received light beam angle θ2 to the same angle as the light projection beam angle θ1.

[0090] As described above, there is a correlation between the slope of the approximation line relative to the value of the projection phase and the projection beam angle θ1. Also, there is a correlation between the slope of the approximation line relative to the value of the reception phase and the reception beam angle θ2. While maintaining the variation in the projection phase difference Δω1, the phase control unit 51 changes the projection beam angle θ1 by changing the projection phases of each of the multiple transmitting arrays 31 so that the slope of the approximation line relative to the value of the projection phase changes. Also, the phase control unit 51 changes the projection beam angle θ1 while maintaining the projection beam diameter φ1.

[0091] Furthermore, while maintaining the state in which there is variation in the light-receiving phase difference Δω2, the phase control unit 51 changes the light-receiving phase of each of the multiple receiving arrays 41 to change the slope of the approximation line relative to the value of the light-receiving phase, thereby changing the light-receiving beam angle θ2. The phase control unit 51 also changes the light-receiving beam angle θ2 while maintaining the light-receiving beam diameter φ2. Then, in step S20, the phase control unit 51 also controls the light-receiving phase so that the light-receiving beam angle θ2 is the same as the light-projecting beam angle θ1.

[0092] Then, in step S21, the object-detecting unit 80 determines whether the peak of the processed signal received from the signal processing unit 60 is equal to or greater than the determination threshold, similar to the process in step S11. That is, the object-detecting unit 80 determines whether the peak of the processed signal obtained from the signal processing unit 60 after changing the projecting beam angle θ1 and the receiving beam angle θ2 is equal to or greater than the determination threshold. If the object-detecting unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to the process in step S100. On the other hand, if the object-detecting unit 80 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to the process in step S22.

[0093] In step S22, the object-detecting unit 80 determines whether or not the entire predetermined scanning range has been scanned. For example, if the scanning range is set in advance to cover the entire area of ​​the irradiation window 11, the object-detecting unit 80 determines whether or not the processes of steps S20 and S21 have been performed on the entire area of ​​the irradiation window 11 by changing the projecting beam angle θ1 and the receiving beam angle θ2.

[0094] The object determination unit 80 repeats the processes of steps S20 to S22 until it determines that the peak of the processed signal is equal to or greater than the determination threshold, or until the processes of steps S20 and S21 have been executed for the entire range of the irradiation window 11. As a result, when the laser radar device 1 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, it scans the entire range of the irradiation window 11 by gradually changing the projection beam angle θ1 and the reception beam angle θ2. Furthermore, in the laser radar device 1, when an object A is attached to the irradiation window 11, the light receiving unit 40 receives reflected light reflected by the object A. Then, in the laser radar device 1, the signal processing unit 60 outputs a processing signal to the object determination unit 80 every time the light receiving unit 40 receives reflected light.

[0095] If it is determined that the peak of the processed signal is equal to or greater than the determination threshold, then in step S100, the object determination unit 80 determines that object A is attached to the irradiation window 11, outputs the determination result to the vehicle control device, and ends the object detection mode process. On the other hand, if it is determined in step S22 that the entire predetermined scanning range has been scanned, then the object determination unit 80 proceeds to step S200. Then, in step S200, the object determination unit 80 determines that object A is not attached to the irradiation window 11, and ends the object detection mode process.

[0096] As described above, the phase control unit 51 of this embodiment changes the light projection beam diameter φ1 in addition to the light projection intensity by controlling the variation in the light projection phase difference Δω1, and changes the light reception beam diameter φ2 in addition to the light reception sensitivity by controlling the variation in the light reception phase difference Δω2. The phase control unit 51 makes the light projection beam diameter φ1 in the object detection mode larger than the light reception beam diameter φ2 in the object detection mode.

[0097] According to this, in the object detection mode, the light projection distance L1 is limited, making it difficult for multiple reflections to occur between the light projection unit 30 and the irradiation window 11. Furthermore, in the object detection mode, the light reception range R2 is limited, making it easier for the light reception unit 40 to receive reflected light from an object A attached to the irradiation window 11.

[0098] (Third embodiment) Next, a third embodiment will be described with reference to Figures 11 to 15. The diameter φ1 of the light projecting beam and the diameter φ2 of the light receiving beam when the object detection mode is executed are different from those of the first embodiment, and part of the processing executed by the laser radar device 1 in the object detection mode is the same as that of the first embodiment. Other than this, the third embodiment is the same as the first embodiment. Therefore, in this embodiment, the differences from the first embodiment will be mainly described, and a description of the same parts as the first embodiment may be omitted.

[0099] 11, when executing the object detection mode, the phase control unit 51 of this embodiment gradually reduces the projecting beam diameter φ1 and the receiving beam diameter φ2 over time. Specifically, the phase control unit 51 controls the light projecting phases of the multiple transmitting arrays 31 and the light receiving phases of the multiple receiving arrays 41 to control the projecting beam diameter φ1 and the receiving beam diameter φ2 so that the detection range RA gradually decreases. The phase control unit 51 of this embodiment reduces the projecting beam diameter φ1 and the receiving beam diameter φ2 in three stages over time.

[0100] A specific object detection mode executed by the laser radar device 1 of this embodiment will be described with reference to Fig. 12. Note that the processes of steps S10, S11, S100, and S200 shown in Fig. 12 are similar to the processes of steps S10, S11, S100, and S200 shown in Fig. 8 and described, and therefore detailed description thereof will be omitted.

[0101] First, in step S10, as shown in FIG. 7, the phase control unit 51 increases the variation in the light projection phase difference Δω1 and the variation in the light reception phase difference Δω2 compared to the normal mode. Then, as shown in FIG. 11, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 so that the light projection range R1 can cover substantially the entire area of ​​the irradiation window 11 and the light projection beam angle θ1 is substantially horizontal. The phase control unit 51 also controls the light reception phases of the multiple receiving arrays 41 so that the light reception range R2 can cover substantially the entire area of ​​the irradiation window 11 and the light reception beam angle θ2 is substantially horizontal. The phase control unit 51 also controls the light projection phases of the multiple transmitting arrays 31 and the light reception phases of the multiple receiving arrays 41 so that the light projection range R1 and the light reception range R2 are substantially equal to each other and the light projection beam diameter φ1 and the light reception beam diameter φ2 are substantially equal to each other.

[0102] Furthermore, in this embodiment, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 so that the light projection distance L1 is slightly longer than the distance from the light projector 30 to the irradiation window 11. The phase control unit 51 also controls the light reception phases of the multiple receiving arrays 41 so that the light reception distance L2 is slightly longer than the distance from the light receiver 40 to the irradiation window 11. Hereinafter, among the processes performed in the object detection mode, the process performed by controlling the light projection phase and the light reception phase so that the detection range RA can cover substantially the entire area of ​​the irradiation window 11 will also be referred to as the first detection mode. In the first detection mode shown in FIG. 11, the detection range RA is indicated by a dashed line.

[0103] Subsequently, in step S11, the object determination unit 80 determines whether the peak of the processed signal is equal to or greater than the determination threshold. If the object determination unit 80 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, the process proceeds to step S200. In step S200, the object determination unit 80 determines that no object A is attached to the irradiation window 11, and ends the process of the object detection mode. On the other hand, if the object determination unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, the process proceeds to step S30. The processes from step S30 onwards are executed when the object determination unit 80 determines that object A is attached to the irradiation window 11 in the first detection mode.

[0104] In step S30, while maintaining the state in which the light-projection phase difference Δω1 varies, the phase control unit 51 reduces the variation to be less than the variation in the light-projection phase difference Δω1 in the first detection mode, as shown by the solid line in Fig. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light-projection phase difference Δω1 to be less than the magnitude of the light-projection phase difference Δω1 in the first detection mode, thereby reducing the degree of variation in the difference in the light-projection phase difference Δω1 to be less than in the first detection mode. Then, as shown in Fig. 11, the phase control unit 51 reduces the light-projection beam diameter φ1 to be less than the light-projection beam diameter φ1 set in the first detection mode.

[0105] Furthermore, while maintaining the variation in the light-receiving phase difference Δω2, the phase control unit 51 reduces the variation as shown by the solid line in Fig. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light-receiving phase difference Δω2 to be smaller than the magnitude of the light-receiving phase difference Δω2 in the first detection mode, thereby reducing the degree of variation in the light-receiving phase difference Δω2 compared to the first detection mode. Then, as shown in Fig. 11, the phase control unit 51 reduces the light-receiving beam diameter φ2 to be smaller than the light-receiving beam diameter φ2 set in the first detection mode.

[0106] By reducing the variation in the light projection phase difference Δω1 and thereby reducing the light projection beam diameter φ1, the cross-sectional area perpendicular to the line extending along the light projection beam angle θ1 in the light projection range R1 becomes smaller, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the light projection phases of the multiple transmitting arrays 31 so that the light projection range R1 includes the upper end of the irradiation window 11.

[0107] Furthermore, by reducing the variation in the light-receiving phase difference Δω2 and thereby reducing the received beam diameter φ2, the cross-sectional area perpendicular to the line extending along the received beam angle θ2 in the light-receiving range R2 becomes smaller, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the light-receiving phase so that the received beam angle θ2 is the same as the projected beam angle θ1. This allows the laser radar device 1 to irradiate light at a predetermined projected beam angle θ1 and receive reflected light from a received beam angle θ2 that is the same as the projected beam angle θ1, as shown in Fig. 11.

[0108] Hereinafter, among the processes executed in the object detection mode, the process executed by reducing the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 to make the light projection beam diameter φ1 and the light reception beam diameter φ2 one step smaller than those in the first detection mode will also be referred to as the second detection mode. In the second detection mode shown in FIG. 11, the dashed line indicates the detection range RA. In addition, in FIG. 13, the solid line indicates the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 in the second detection mode. In addition, in FIG. 14, the solid line indicates the light projection intensity and the light reception sensitivity in the second detection mode.

[0109] Then, in step S31, the object-determining unit 80 performs a position detection process shown in FIG. 15 to detect an attachment position indicating the position where the object A is attached. Specifically, as shown in FIG. 15, in step S310, the object-determining unit 80 determines whether the peak of the processed signal acquired from the signal processing unit 60 after reducing the light projecting beam diameter φ1 and the light receiving beam diameter φ2 in step S30 is equal to or greater than a determination threshold. If the object-determining unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S311. If the object-determining unit 80 does not determine that the peak of the processed signal is equal to or greater than the determination threshold, it proceeds to step S312. The determination threshold used in step S310 may be the same as or different from the determination threshold used in step S11.

[0110] In step S311, the object determination unit 80 determines that object A is present within the detection range RA set in step S30, and detects the position of object A. The position of object A detected in step S311 is a portion within the detection range RA where a light projection range R1, determined by the light projection beam angle θ1 and the light projection beam diameter φ1 on the irradiation window 11, overlaps with a light reception range R2, determined by the light reception beam angle θ2 and the light reception beam diameter φ2. The position of object A includes a range of a predetermined size set by the light projection range R1 and the light reception range R2. In contrast, in step S312, the object determination unit 80 determines that object A is not present within the detection range RA set in step S30.

[0111] In this way, the detection range RA can be limited by reducing the variation in the light projection phase difference Δω1 to reduce the light projection beam diameter φ1 and by reducing the variation in the light reception phase difference Δω2 to reduce the light reception beam diameter φ2 compared to the first detection mode. Then, when a substance A is attached to the irradiation window 11, the position of the substance A can be detected based on the limited detection range RA.

[0112] 12, in step S32, the phase control unit 51 determines whether or not the entire range within the predetermined scanning range has been scanned. That is, the phase control unit 51 determines whether or not the position detection process of step S31 has been executed for the entire predetermined scanning range.

[0113] For example, when the scanning range is set in advance to the entire range of the irradiation window 11, the phase control unit 51 determines whether or not the position detection process has been executed for the entire range of the irradiation window 11. When the phase control unit 51 determines that the position detection process has been executed for the entire range of the irradiation window 11, the process proceeds to step S34, and when the phase control unit 51 does not determine that the position detection process has been executed for the entire range of the irradiation window 11, the process proceeds to step S33.

[0114] In step S33, while maintaining the second detection mode, the phase control unit 51 changes the magnitude of each of the light projection phase difference Δω1 and the light reception phase difference Δω2 to change the light projection beam angle θ1 and the light reception beam angle θ2 downward, as shown in Fig. 11. Specifically, the phase control unit 51 changes each of the light projection phases so as to change the slope of the approximation line relative to the value of the light projection phase, thereby changing the light projection beam angle θ1 while maintaining the size of the light projection beam diameter φ1. When changing the light projection beam angle θ1, the phase control unit 51 controls the light projection phase so that part of the light projection range R1 after the change is included in the light projection range R1 before the change.

[0115] Furthermore, the phase control unit 51 changes the light-receiving phase so as to change the slope of the approximation line relative to the value of the light-receiving phase, thereby changing the light-receiving beam angle θ2 while maintaining the size of the light-receiving beam diameter φ2. When changing the light-receiving beam angle θ2, the phase control unit 51 controls the light-receiving phase so that part of the light-receiving range R2 after the change is included in the light-receiving range R2 before the change. Furthermore, the phase control unit 51 controls the light-receiving phase so that the light-receiving beam angle θ2 is the same angle as the light-projecting beam angle θ1. Then, in step S31, the object determination unit 80 performs the position detection process again. The object determination unit 80 determines whether or not an object A is present within the detection range RA set in step S33.

[0116] The laser radar device 1 repeats the processes of steps S31 to S33 until the position detection process is performed for the entire range of the irradiation window 11. As a result, the laser radar device 1 gradually changes the light projection beam angle θ1 and the light reception beam angle θ2 in the second detection mode to scan the entire range of the irradiation window 11, and the object determination unit 80 performs the position detection process for the entire range of the irradiation window 11.

[0117] Furthermore, if it is determined in step S32 that the position detection process has been performed for the entire range of the irradiation window 11, the phase control unit 51 determines in step S34 whether or not a predetermined all-detection mode in the object detection mode has been performed. In this embodiment, the light projecting beam diameter φ1 and the light receiving beam diameter φ2 are set to be reduced by three stages in the object detection mode, and the operation mode can be changed from the first detection mode to the second detection mode, a third detection mode (described later), and a fourth detection mode (described later). Therefore, the object determination unit 80 in this embodiment determines in step S34 whether or not these all-detection modes have been performed.

[0118] If the phase control unit 51 determines that the predetermined full detection mode has been executed, the process proceeds to step S100. On the other hand, if the phase control unit 51 does not determine that the predetermined full detection mode has been executed, the process returns to step S30.

[0119] Returning to the processing of step S30, the phase control unit 51 maintains the state in which there is variation in the light projection phase difference Δω1, and reduces the variation further than in the second detection mode, as indicated by the dashed-dotted line in Fig. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light projection phase difference Δω1 to be smaller than the magnitude of the light projection phase difference Δω1 in the second detection mode, thereby reducing the degree of variation in the difference in the light projection phase difference Δω1 to be smaller than in the second detection mode. Then, as shown in Fig. 11, the phase control unit 51 reduces the light projection beam diameter φ1 to be smaller than the light projection beam diameter φ1 set in the second detection mode.

[0120] Furthermore, while maintaining the state in which there is variation in the light-receiving phase difference Δω2, the phase control unit 51 further reduces the variation compared to the second detection mode, as shown by the dashed line in Fig. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light-receiving phase difference Δω2 to be smaller than the magnitude of the light-receiving phase difference Δω2 in the second detection mode, thereby reducing the degree of variation in the light-receiving phase difference Δω2 compared to the second detection mode. Then, as shown in Fig. 11, the phase control unit 51 reduces the light-receiving beam diameter φ2 set in the second detection mode.

[0121] By reducing the projection beam diameter φ1, the cross-sectional area perpendicular to the line extending along the projection beam angle θ1 in the projection range R1 is reduced, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the projection phases of the multiple transmitting arrays 31 so that the projection range R1 includes the upper end of the irradiation window 11.

[0122] Furthermore, by reducing the received beam diameter φ2, the cross-sectional area perpendicular to a line extending along the received beam angle θ2 in the light-receiving range R2 is reduced, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the received beam phase so that the received beam angle θ2 is the same as the projected beam angle θ1. This enables the laser radar device 1 to irradiate light at a predetermined projected beam angle θ1 and receive reflected light from a received beam angle θ2 that is the same as the projected beam angle θ1, as shown by the dashed dotted line in Fig. 14.

[0123] Hereinafter, among the processes executed in the object detection mode, the process executed by reducing the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 to make the light projection beam diameter φ1 and the light reception beam diameter φ2 one step smaller than those in the second detection mode will also be referred to as the third detection mode. In the third detection mode shown in FIG. 11, the dashed line indicates the detection range RA. In FIG. 13, the dashed-dotted line indicates the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 in the third detection mode. In FIG. 14, the dashed-dotted line indicates the light projection intensity and the light reception sensitivity in the third detection mode.

[0124] Then, by repeatedly executing steps S31 to S33, the object determining unit 80 of the laser radar device 1 executes position detection processing for the entire range of the irradiation window 11 based on the variations in the light-projection phase difference Δω1 and the light-reception phase difference Δω2 in the third detection mode. Specifically, while maintaining the third detection mode, the phase control unit 51 changes the magnitudes of the light-projection phase difference Δω1 and the light-reception phase difference Δω2, thereby shifting the light-projection beam angle θ1 and the light-reception beam angle θ2 downward as shown in FIG. 11 . The phase control unit 51 controls the light-projection phase so that part of the light-projection range R1 after the change is included within the light-projection range R1 before the change. Furthermore, the phase control unit 51 controls the light-reception phase so that part of the light-reception range R2 after the change is included within the light-reception range R2 before the change.

[0125] Furthermore, the phase control unit 51 controls the light receiving phase so that the light receiving beam angle θ2 is the same as the light projecting beam angle θ1. As a result, the object determining unit 80 scans the entire range of the irradiation window 11 with finer angle changes than in the second detection mode. The laser radar device 1 repeats the processes of steps S31 to S34 until the processes of the entire detection mode are completed.

[0126] Furthermore, by performing the position detection process of step S31 based on the third detection mode, the projected light beam diameter φ1 and the received light beam diameter φ2 are smaller when the position detection process is performed compared to when the position detection process is performed based on the second detection mode. This reduces the respective detection ranges RA when the position detection process is repeatedly performed. Therefore, the detection accuracy of the adhesion position detected in the position detection process performed in the third detection mode can be improved compared to the detection accuracy of the adhesion position detected in the position detection process performed in the second detection mode.

[0127] Furthermore, if the processing in the full detection mode has not ended after the processing in steps S30 to S33 has been performed in the third detection mode, the process returns to step S30. Then, the phase control unit 51 further reduces the variation in the light-projection phase difference Δω1, as indicated by the two-dot chain line in FIG. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light-projection phase difference Δω1 to be smaller than the magnitude of the light-projection phase difference Δω1 in the third detection mode, thereby reducing the degree of variation in the light-projection phase difference Δω1 to be smaller than in the third detection mode. Then, as shown in FIG. 11, the phase control unit 51 reduces the light-projection beam diameter φ1 to be smaller than the light-projection beam diameter φ1 set in the third detection mode.

[0128] Furthermore, the phase control unit 51 further reduces the variation in the light-receiving phase difference Δω2 compared to the third detection mode, as indicated by the two-dot chain line in Fig. 13. Specifically, the phase control unit 51 reduces the magnitude of a portion of the light-receiving phase difference Δω2 to be smaller than the magnitude of the light-receiving phase difference Δω2 in the third detection mode, thereby reducing the degree of variation in the light-receiving phase difference Δω2 compared to the third detection mode. Then, the phase control unit 51 reduces the light-receiving beam diameter φ2 set in the third detection mode, as shown in Fig. 11.

[0129] By reducing the projection beam diameter φ1, the cross-sectional area perpendicular to the line extending along the projection beam angle θ1 in the projection range R1 is reduced, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the projection phases of the multiple transmitting arrays 31 so that the projection range R1 includes the upper end of the irradiation window 11.

[0130] Furthermore, by reducing the received beam diameter φ2, the cross-sectional area perpendicular to a line extending along the received beam angle θ2 in the light-receiving range R2 becomes smaller, as shown in Fig. 11. Furthermore, the phase control unit 51 controls the received light phase so that the received beam angle θ2 is the same as the projected beam angle θ1. This allows the laser radar device 1 to irradiate light at a predetermined projected beam angle θ1 and receive reflected light from a received beam angle θ2 that is the same as the projected beam angle θ1, as shown in Fig. 11.

[0131] Hereinafter, among the processes executed in the object detection mode, the process executed by reducing the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 to make the light projection beam diameter φ1 and the light reception beam diameter φ2 one step smaller than those in the third detection mode will also be referred to as the fourth detection mode. In the fourth detection mode shown in FIG. 11, the dashed line indicates the detection range RA. In addition, in FIG. 13, the two-dot chain line indicates the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 in the fourth detection mode. In addition, in FIG. 14, the two-dot chain line indicates the light projection intensity and the light reception sensitivity in the fourth detection mode.

[0132] In this embodiment, the phase control unit 51 sets the light projection phase difference Δω1 in the fourth detection mode to a constant value, similar to that in the normal mode, and sets the light reception phase difference Δω2 in the fourth detection mode to a constant value, similar to that in the normal mode. However, the light projection phase difference Δω1 and the light reception phase difference Δω2 in the fourth detection mode may vary in magnitude as long as they are smaller than those in the third detection mode.

[0133] Then, by repeatedly executing steps S31 to S33, the object determining unit 80 of the laser radar device 1 executes position detection processing for the entire range of the irradiation window 11 based on the light-projection phase difference Δω1 and the light-reception phase difference Δω2 in the fourth detection mode. Specifically, while maintaining the fourth detection mode, the phase control unit 51 changes the magnitudes of the light-projection phase difference Δω1 and the light-reception phase difference Δω2 to change the light-projection beam angle θ1 and the light-reception beam angle θ2 downward as shown in FIG. 11 . The phase control unit 51 controls the light-projection phase so that part of the light-projection range R1 after the change is included within the light-projection range R1 before the change. Furthermore, the phase control unit 51 controls the light-reception phase so that part of the light-reception range R2 after the change is included within the light-reception range R2 before the change.

[0134] Furthermore, the phase control unit 51 controls the light receiving phase so that the light receiving beam angle θ2 is the same as the light projecting beam angle θ1. As a result, the object determining unit 80 scans the entire range of the irradiation window 11 with finer angle changes than in the third detection mode. The laser radar device 1 repeats the processes of steps S31 to S34 until the process of the fourth detection mode is completed.

[0135] Furthermore, by performing the position detection process of step S31 based on the fourth detection mode, the projected light beam diameter φ1 and the received light beam diameter φ2 are smaller when the position detection process is performed compared to when the position detection process is performed based on the third detection mode. This reduces the respective detection ranges RA when the position detection process is repeatedly performed. Therefore, the detection accuracy of the adhesion position detected in the position detection process performed in the fourth detection mode can be further improved compared to the accuracy of the adhesion position detected in the position detection process performed in the third detection mode.

[0136] In this way, the phase control unit 51 of this embodiment gradually reduces the projection beam diameter φ1 and the reception beam diameter φ2 each time the entire range of the irradiation window 11 is scanned. When an object A is attached to the irradiation window 11, the laser radar device 1 receives the reflected light from the object A multiple times in the object detection mode by having the light receiving unit 40 receive the reflected light from the object A in each detection mode. Then, in the laser radar device 1, each time the light receiving unit 40 receives reflected light, the signal processing unit 60 performs various signal processing on the received light signal according to the intensity of the reflected light, and outputs the processed signal to the object determination unit 80. Therefore, the object determination unit 80 detects the position of the object each time the laser radar device 1 scans the entire range of the irradiation window 11.

[0137] Furthermore, if it is determined in step S34 that the processing in the full detection mode has been executed, in step S100, the object determination unit 80 determines that an object A is attached to the irradiation window 11 and outputs the determination result to the vehicle control device. The object determination unit 80 also outputs information on the detected attachment position to the vehicle control device. Then, the processing in the object detection mode ends.

[0138] When the vehicle control device receives from the laser radar device 1 a determination result indicating that object A is attached to the irradiation window 11 and information on the attachment position, the vehicle control device performs vehicle control corresponding to the state in which object A is attached to the irradiation window 11. For example, if the vehicle is equipped with a removal device that removes object A attached to the irradiation window 11 using water pressure or the like, the vehicle control device may operate the removal device at the detected position to reliably remove the attached object A. Furthermore, if object A cannot be removed, the vehicle control device may invalidate information about object T obtained in the normal mode that is obtained based on reflected light received from the direction corresponding to the detection position at which it was determined that object A is attached.

[0139] As described above, the phase control unit 51 of this embodiment changes the projection beam diameter φ1 and projection beam angle θ1 in addition to the projection intensity by controlling the variation in the projection phase difference Δω1. The phase control unit 51 also changes the reception beam diameter φ2 and reception beam angle θ2 in addition to the light-receiving sensitivity by controlling the variation in the reception phase difference Δω2. When scanning is performed within a predetermined scanning range in the object detection mode, the phase control unit 51 changes the projection beam angle θ1 and reception beam angle θ2, and gradually reduces the projection beam diameter φ1 and reception beam diameter φ2 with each scan. The object determination unit 80 detects the position of an object A adhering to the irradiation window 11 with each scan.

[0140] This allows the detection range RA to be gradually reduced by reducing the light projection beam diameter φ1 and the light reception beam diameter φ2 with each scanning, thereby improving the accuracy of the adhesion position identified by the object determination unit 80 with each scanning. Furthermore, in the laser radar device 1 applied to a vehicle, by identifying the position of the adhesion A, it is possible to, for example, operate a removal device for the adhesion A at the identified position to remove the adhesion A attached to the irradiation window 11. Furthermore, if the adhesion A cannot be removed, the information about the object T obtained in the normal mode based on reflected light from the direction corresponding to the detection position of the adhesion A can be invalidated, thereby suppressing the influence of the adhesion A attached to the irradiation window 11.

[0141] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIGS. 16 to 20. In this embodiment, a part of the processing that the laser radar device 1 executes in the object detection mode is different from that in the third embodiment. The rest is the same as in the third embodiment. Therefore, in this embodiment, the parts that are different from the third embodiment will be mainly described, and the description of the parts that are the same as in the third embodiment may be omitted.

[0142] A specific object detection mode executed by the laser radar device 1 of this embodiment will be described with reference to Fig. 16. The laser radar device 1 of this embodiment executes the object detection mode shown in Fig. 16 when, for example, an object T is present around the host vehicle and the distance between the host vehicle and the object T changes over time due to the host vehicle traveling, as shown in Fig. 17. Note that the processes of steps S10, S11, S30, S32, S33, S100, and S200 shown in Fig. 16 are similar to the processes of S10, S11, S30, S32, S33, S100, and S200 shown and described in Fig. 12, and therefore detailed description thereof will be omitted.

[0143] The laser radar device 1 of this embodiment executes the process of step S30 or step S33, and then executes the process of step S35. In step S35, the object-determining unit 80 executes the candidate position detection process shown in Fig. 18 for detecting the candidate position of the object A. Specifically, as shown in Fig. 18, in step S350, the object-determining unit 80 determines whether the peak of the processed signal acquired from the signal processing unit 60 after reducing the projected beam diameter φ1 and the received beam diameter φ2 in step S30 or step S33 is equal to or greater than the determination threshold.

[0144] If the object-determining unit 80 determines that the peak of the processed signal is equal to or greater than the determination threshold, the process proceeds to step S351, and if it does not determine that the peak of the processed signal is equal to or greater than the determination threshold, the process proceeds to step S352. The determination threshold used in step S350 may be the same as or different from the determination threshold used in step S11.

[0145] If it is determined that the peak of the processed signal is equal to or greater than the determination threshold, then in step S351 the object determination unit 80 determines that there is a possibility that object A is present within the detection range RA set in step S30 or step S33. If it is determined in step S351 that there is a possibility that object A is present, then the object determination unit 80 stores information about the position where object A may be present as a candidate position for object A.

[0146] The candidate position of the object A detected in step S351 is a portion within the detection range RA where the light projection range R1 and the light reception range R2 on the irradiation window 11 overlap, and includes a range of a predetermined size set by the light projection range R1 and the light reception range R2. On the other hand, if it is not determined that the peak of the processed signal is equal to or greater than the determination threshold, in step S352 the object determination unit 80 determines that the object A is not present within the detection range RA set in step S30 or step S33.

[0147] 16, in step S32, the phase control unit 51 determines whether scanning has been performed on the entire predetermined scanning range. That is, the phase control unit 51 determines whether the object determination unit 80 has performed the candidate position detection process of step S35 on the entire predetermined scanning range.

[0148] For example, when the scanning range is set in advance to the entire range of the irradiation window 11, the phase control unit 51 determines whether or not the candidate position detection process has been executed for the entire range of the irradiation window 11. When the phase control unit 51 determines that the candidate position detection process has been executed for the entire range of the irradiation window 11, the process proceeds to step S40, and when the phase control unit 51 does not determine that the candidate position detection process has been executed for the entire range of the irradiation window 11, the process proceeds to step S33.

[0149] The phase control unit 51 repeats the processes of steps S32, S33, and S35 until the candidate position detection process has been performed for the entire range of the irradiation window 11. As a result, the laser radar device 1 gradually changes the projecting beam angle θ1 and the receiving beam angle θ2 while maintaining the respective sizes of the projecting beam diameter φ1 and the receiving beam diameter φ2, thereby scanning the entire range of the irradiation window 11. The object determination unit 80 then performs the candidate position detection process for the entire range of the irradiation window 11, and detects the candidate position of the object A.

[0150] If it is determined in step S32 that the candidate position detection process has been performed for the entire range of the irradiation window 11, then in step S40, the phase control unit 51 determines whether scanning of the entire scanning range has been performed a predetermined number of times. Hereinafter, scanning a predetermined number of times is referred to as a scanning cycle.

[0151] If the phase control unit 51 determines that a scanning cycle has been executed, the process proceeds to step S42; if it does not determine that a scanning cycle has been executed, the process proceeds to step S41. The number of scans is set to a number necessary to identify the adhesion position in the position identification process described below that is executed in step S42. In this embodiment, the predetermined number of scans is set to, for example, three. However, the number of scans is not limited to three, and may be set to a number other than three as long as the adhesion position can be identified in the position identification process.

[0152] In step S41, the phase control unit 51 returns the light projection beam angle θ1 and the light reception beam angle θ2 to the angles set in step S30 in order to again execute the candidate position detection process for the entire range of the irradiation window 11. Specifically, the phase control unit 51 controls the light projection phase difference Δω1 and the light reception phase difference Δω2 so that the light projection range R1 and the light reception range R2 each include the upper end of the irradiation window 11. Furthermore, the phase control unit 51 maintains the light projection beam diameter φ1 and the light reception beam diameter φ2 in the second detection mode, and changes the light projection beam angle θ1 and the light reception beam angle θ2 while maintaining the light projection intensity and light reception sensitivity in the second detection mode.

[0153] Then, by repeatedly executing steps S32, S33, and S35, the object determination unit 80 executes the candidate position detection process for the entire range of the irradiation window 11 and again detects the candidate position of the object A. In other words, the object determination unit 80 executes a scanning cycle in which the entire range of the irradiation window 11 is scanned the number of times by changing the projecting beam angle θ1 and the receiving beam angle θ2 without changing the projecting beam diameter φ1 and the receiving beam diameter φ2.

[0154] The laser radar device 1 repeatedly executes the processes of steps S32, S33, S35, S40, and S41 until a scanning cycle is executed. As a result, in the laser radar device 1, the light receiving unit 40 receives reflected light from the object A every time scanning is executed, and the signal processing unit 60 outputs a processed signal to the object determination unit 80. Therefore, in the second detection mode, the laser radar device 1 acquires processed signals from the signal processing unit 60 the number of scans. Then, information on candidate positions of the object A detected by executing scanning of the entire range of the irradiation window 11 the number of scans is stored in the object determination unit 80 for the number of scans or more.

[0155] Then, in step S42, the object determination unit 80 performs a position identification process shown in Fig. 19 for identifying an attachment position based on the stored information on the candidate positions of the object A that have appeared multiple times or more. Specifically, as shown in Fig. 19, in step S420, the object determination unit 80 determines whether or not the number of identical candidate positions among the stored candidate positions of the object A that have appeared multiple times or more is equal to or greater than a predetermined determination number. If the object determination unit 80 determines that the number of identical candidate positions is equal to or greater than the predetermined determination number, the process proceeds to step S421, and if it does not determine that the number of identical candidate positions is equal to or greater than the predetermined determination number, the process proceeds to step S422.

[0156] If it is determined that the number of identical candidate positions is equal to or greater than the predetermined determination number, in step S421, the object determination unit 80 identifies the candidate positions of the object A that are equal to or greater than the determination number as positions where the object A is attached. On the other hand, if the number of identical candidate positions is less than the predetermined determination number, in step S422, the object determination unit 80 determines that the object A is not attached to the detected candidate positions. The predetermined determination number is set based on the number of scans, which is the number of scans performed on the entire range of the irradiation window 11. The predetermined determination number may be set to the same number as the number of scans, or may be set to a number smaller than the number of scans, such as 2 / 3 of the number of scans. The closer the determination number is to the number of scans, the more accurately the object A can be detected. In this embodiment, the predetermined determination number is set to the same number as the number of scans.

[0157] The reason why the laser radar device 1 of this embodiment performs scanning of the entire range of the irradiation window 11 the number of scans and identifies the position of the attachment A based on whether the number of identical candidate positions is equal to or greater than a predetermined judgment number will be explained with reference to Figures 17 and 20.

[0158] 17, when an object A is attached to the irradiation window 11, the laser radar device 1 receives reflected light from the object A in the object detection mode. When the laser radar device 1 determines that a processed signal corresponding to the intensity of the reflected light from the object A is equal to or greater than the determination threshold, it identifies the attachment position based on the reflected light corresponding to the processed signal equal to or greater than the determination threshold.

[0159] 17, if an object T is present near the irradiation window 11, there is a risk that the reflected light from the object T may be received by making the light projection distance L1 and the light reception distance L2 longer than the distance to the irradiation window 11. In this case, if the processed signal corresponding to the intensity of the reflected light from the object T is equal to or greater than the determination threshold, the laser radar device 1 may erroneously determine that the position of the object T is an attachment position.

[0160] Here, Fig. 20 shows an example of a processed signal output by the laser radar device 1 when an object T is present near the irradiation window 11 while the vehicle is traveling. The three processed signals in Fig. 20 are assumed signals when the laser radar device 1 outputs a processed signal three times while the vehicle is traveling. Specifically, of the three processed signals shown in Fig. 20, the processed signal indicated by the solid line indicates the processed signal that is output earliest out of the three times, the dashed dotted line indicates the processed signal that is output next, and the dashed two dotted line indicates the processed signal that is output last.

[0161] When an attachment A is attached to the irradiation window 11 and an object T is present near the irradiation window 11, each of the three processed signals may include two peaks, as shown in Fig. 20. This is because the laser radar device 1 receives reflected light that includes reflected light from the attachment A and reflected light from the object T. In the example shown in Fig. 20, the peak on the side closer to the laser radar device 1 indicates a peak based on reflected light from the attachment A, and the peak on the side farther from the laser radar device 1 indicates a peak based on reflected light from the object T.

[0162] When the vehicle is traveling, the distance and direction from the laser radar device 1 to the object T change over time. Therefore, as shown in Fig. 20, the shape of each of the three processed signals changes in the position and size of the peak on the side farther away from the laser radar device 1 depending on the elapsed time. That is, as the distance and direction from the laser radar device 1 to the object T change, the shape of the peak portion of the processed signal based on the reflected light from the object T changes relatively significantly. Also, as shown in Fig. 20, the three processed signals include signals in which the peak based on the reflected light from the object T exceeds the determination threshold and signals in which it does not exceed the determination threshold.

[0163] In contrast, the shapes of the three processed signals are such that the position and magnitude of the peak on the side closer to the laser radar device 1 are substantially constant. In other words, the shapes of the peaks based on the light reflected from the object A in the processed signals hardly change. Therefore, as shown in Fig. 20, the peaks based on the light reflected from the object A in all three processed signals exceed the determination threshold.

[0164] Therefore, when a scanning cycle is performed in which the entire range of the irradiation window 11 is scanned a number of times, even if the candidate position detection process detects the position of the object T as a candidate position of the attachment A, the number of candidate positions detected based on the position of the object T will be less than the number of scans. In contrast, if the candidate position detected by the candidate position detection process is a position based on the attachment A, the number of candidate positions detected will be the same as or approximately the same as the number of scans.

[0165] As described above, the laser radar device 1 of this embodiment executes a scanning cycle in which scanning is performed on the entire range of the irradiation window 11 for the number of scans, and identifies, among the candidate positions of the object A that have been scanned for the stored number of scans or more, the candidate positions for which the number of identical positions is equal to or greater than a predetermined determination number, as the positions of the object A. By identifying the object position in this manner, the accuracy of the object position identified in the position detection process can be further improved.

[0166] If it is determined in step S34 that the processing in the full detection mode has been executed, then in step S100, the object determination unit 80 determines that an object A is attached to the irradiation window 11 and outputs the determination result to the vehicle control device. The object determination unit 80 also outputs information on the identified attachment position to the vehicle control device. Then, the processing in the object detection mode ends.

[0167] As described above, the phase control unit 51 of this embodiment can change the projection beam angle θ1 in addition to the light projection intensity by controlling the variation in the projection phase difference Δω1, and can change the receiving beam angle θ2 in addition to the light receiving sensitivity by controlling the variation in the receiving phase difference Δω2. In the object detection mode, when scanning to detect an object A for each predetermined scanning range is performed a predetermined number of times, the phase control unit 51 changes the projection beam angle θ1 and the receiving beam angle θ2 while maintaining the projection intensity and the light receiving sensitivity. When scanning is performed a predetermined number of times and multiple processing signals are acquired from the signal processing unit 60, the object determination unit 80 detects multiple candidate positions based on the acquired processing signals, and if the number of candidate positions that indicate the same position is equal to or greater than a predetermined number of determinations, the object determination unit 80 identifies the candidate position with the predetermined number or more determinations as the object adhesion position.

[0168] The reason why the object determination unit 80 makes such a determination is that, as described above, if an object T is present near the irradiation window 11, the light receiving unit 40 may receive light reflected from the object T. When receiving light reflected from the object T, the object determination unit 80 may erroneously determine the position of the object T as an attachment position. However, by having the object determination unit 80 determine the attachment position as in this embodiment, it is possible to prevent the position of the object T from being erroneously determined as an attachment position, and further improve the accuracy of the attachment position identified in the attachment detection mode.

[0169] (Fifth embodiment) Next, a fifth embodiment will be described with reference to FIG. 21. In this embodiment, a part of the position identification process executed by the laser radar device 1 in the object detection mode is different from that in the fourth embodiment. The rest is the same as in the fourth embodiment. Therefore, in this embodiment, the differences from the fourth embodiment will be mainly described, and a description of the same parts as in the fourth embodiment may be omitted.

[0170] The position identification process executed by the laser radar device 1 of this embodiment will be described with reference to Fig. 21. In step S42 shown in the fourth embodiment, the object determination unit 80 of this embodiment performs the position identification process shown in Fig. 21 to identify the attachment position based on the stored information on the candidate positions of the object A for multiple occurrences.

[0171] 21, in step S425, the object determination unit 80 determines whether or not the average value of the peaks of multiple processed signals indicating the same candidate position among the stored multiple or more candidate positions of object A is equal to or greater than the determination threshold. If the object determination unit 80 determines that the average value of the peaks of multiple processed signals indicating the same candidate position is equal to or greater than the determination threshold, the process proceeds to step S421, and if it does not determine that the average value of the peaks of multiple processed signals indicating the same candidate position is equal to or greater than the determination threshold, the process proceeds to step S422.

[0172] If the average value of the peaks of multiple processed signals indicating the same candidate position is equal to or greater than the judgment threshold, in step S421, the object determination unit 80 identifies the candidate position of object A whose average value of the peaks is equal to or greater than the judgment threshold as an attachment position where object A is attached. On the other hand, if the average value of the peaks is smaller than the judgment threshold, in step S422, the object determination unit 80 determines that object A is not attached to the detected candidate position.

[0173] The reason why the position of the object A is identified as a candidate position of the object A for which the average value of the peaks is equal to or greater than the determination threshold will be explained below.

[0174] As explained in the fourth embodiment, when an object T is present near the irradiation window 11, there is a risk of receiving reflected light from the object T by making the light projection distance L1 and the light reception distance L2 longer than the distance to the irradiation window 11. When receiving reflected light from the object T, as shown in Fig. 20, the processed signal may include two peaks: one based on reflected light from an attached matter A and the other based on reflected light from the object T. Therefore, when the processed signal corresponding to the intensity of reflected light from the object T is equal to or greater than the determination threshold, the laser radar device 1 may erroneously determine that the position of the object T is an attachment position.

[0175] However, when the vehicle is traveling, the position and magnitude of the peak in the processed signal based on the reflected light from the object T changes as the distance and direction from the laser radar device 1 to the object T change over time. In contrast, the position and magnitude of the peak in the processed signal based on the reflected light hardly change.

[0176] Therefore, when a scanning cycle is executed in which the entire range of the irradiation window 11 is scanned a certain number of times, even if the candidate position detection process receives a processed signal multiple times in which the peak based on the reflected light from the object T exceeds the decision threshold, the average value of those multiple peaks will be significantly lower than before averaging. As a result, it is expected that the average value of the peaks based on the reflected light from the object T will be smaller than the decision threshold.

[0177] On the other hand, if the processed signal is a signal based on the light reflected from object A, when the processed signal is received multiple times with peaks based on the light reflected from object A exceeding the judgment threshold, it is expected that each of the multiple peaks will be equal to or greater than the judgment threshold. Therefore, the average value of the multiple peaks based on the light reflected from object A will be equal to or greater than the judgment threshold.

[0178] As described above, the laser radar device 1 of this embodiment executes a scanning cycle, and if the average value of the peaks of multiple processed signals indicating the same candidate position is equal to or greater than the judgment threshold, the laser radar device 1 identifies the candidate position as the position of the object A. Identifying the attachment position in this manner can further improve the accuracy of the attachment position identified in the position detection process.

[0179] As described above, the phase control unit 51 of this embodiment can change the projection beam angle θ1 in addition to the light projection intensity by controlling the variation in the projection phase difference Δω1, and can change the receiving beam angle θ2 in addition to the light receiving sensitivity by controlling the variation in the receiving phase difference Δω2. In the object detection mode, when a predetermined number of scans are performed to detect object A within each predetermined scanning range, the phase control unit 51 changes the projection beam angle θ1 and the receiving beam angle θ2 while maintaining the projection intensity and the light receiving sensitivity. After the predetermined number of scans are performed and multiple processed signals are acquired from the signal processing unit 60, the object determination unit 80 detects multiple candidate positions based on the acquired processed signals. If the average value of the peaks of multiple processed signals corresponding to the same candidate positions is equal to or greater than a predetermined determination threshold, the object determination unit 80 identifies the candidate position detected based on the multiple processed signals whose average peak value is equal to or greater than the predetermined determination threshold as the object adhesion position.

[0180] The reason why the object determination unit 80 makes such a determination is that, as described above, if an object T is present near the irradiation window 11, the light receiving unit 40 may receive light reflected from the object T. When receiving light reflected from the object T, the object determination unit 80 may erroneously determine the position of the object T as an attachment position. However, by having the object determination unit 80 determine the attachment position as in this embodiment, it is possible to prevent the position of the object T from being erroneously determined as an attachment position, and further improve the accuracy of the attachment position identified in the attachment detection mode.

[0181] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIGS. 22 to 24. In this embodiment, a part of the processing executed by the laser radar device 1 in the object detection mode differs from that in the fourth embodiment. Specifically, the processing after the variation in the light projection phase difference Δω1 and the variation in the light reception phase difference Δω2 are set to the second detection mode and the position identification processing is executed differs from that in the fourth embodiment. The rest of the processing is the same as that in the fourth embodiment. Therefore, in this embodiment, the parts that are different from the fourth embodiment will be mainly described, and the description of the parts that are the same as those in the fourth embodiment may be omitted.

[0182] A specific object detection mode executed by the laser radar device 1 of this embodiment will be described with reference to Figures 22 to 24. Note that the processing of steps S10, S11, S30, S32 to S35, S40 to S42, S100, and S200 shown in Figure 22 is similar to the processing of steps S10, S11, S30, S32 to S35, S40 to S42, S100, and S200 shown in Figure 16 and described, and therefore detailed description thereof will be omitted.

[0183] In this embodiment, the phase control unit 51 sets the variation in the light projection phase difference Δω1 and the variation in the light reception phase difference Δω2 to the first detection mode in step S10, and irradiates the irradiation light onto substantially the entire range of the irradiation window 11, as shown in Figures 23 and 24. Then, in step S11, the object determination unit 80 determines whether or not an object A is attached to the irradiation window 11 based on whether or not the peak of the processed signal is equal to or greater than the determination threshold.

[0184] If it is determined that an object A is attached to the irradiation window 11, the laser radar device 1 first sets the projected beam diameter φ1 and the received beam diameter φ2 to the second detection mode in step S30. Then, the laser radar device 1 executes steps S35, S32, and S33.

[0185] 23 and 24, the laser radar device 1 performs the candidate position detection process for the entire range of the irradiation window 11 in the second detection mode while gradually changing the light projection beam angle θ1 and the light reception beam angle θ2 in the vertical and horizontal directions. The laser radar device 1 then performs the processes of steps S40 and S41 to perform a scanning cycle and perform the candidate position detection process for the entire range of the irradiation window 11. Then, in step S42, the object determination unit 80 performs a position identification process to identify the approximate position where the object A is attached. The object identification process is performed for each detection range RA set in the second detection mode.

[0186] 23 and 24, in this embodiment, an example will be described in which two attachment positions A are identified in the second detection mode when two attachment positions A are attached to different positions on the irradiation window 11. Hereinafter, one of the two attachment positions A will be referred to as a first attachment A1 and the other as a second attachment A2.

[0187] After the process of step S42, in step S50, the phase control unit 51 reduces the variations in the light projection phase difference Δω1 and the light reception phase difference Δω2 and executes the third detection mode. That is, the phase control unit 51 reduces the light projection beam diameter φ1 to be smaller than the light projection beam diameter φ1 set in the second detection mode, so that the cross-sectional area of ​​the light projection range R1 perpendicular to a line extending along the light projection beam angle θ1 is smaller than the light projection range R1 set in the second detection mode. Also, the phase control unit 51 reduces the light reception beam diameter φ2 to be smaller than the light reception beam diameter φ2 set in the second detection mode, so that the cross-sectional area of ​​the light reception range R2 perpendicular to a line extending along the light reception beam angle θ2 is smaller than the light reception range R2 set in the second detection mode. That is, the phase control unit 51 reduces the detection range RA to be smaller than the detection range RA in the second detection mode.

[0188] In the following step S51, the phase control unit 51 changes the light projecting beam angle θ1 and the light receiving beam angle θ2 so that the detection range RA is included in the range of adhesion positions identified in the second detection mode. Then, in step S52, the object determination unit 80 executes the candidate position detection process again. That is, the object determination unit 80 executes the candidate position detection process for each detection range RA set in the third detection mode. Then, the object determination unit 80 determines whether or not there is a possibility that an object A is present within the detection range RA set in step S51, which is narrower than the detection range RA set in the second detection mode, among the approximate adhesion positions identified in the second detection mode.

[0189] If the peak of the processed signal is equal to or greater than the determination threshold, the object determination unit 80 determines that there is a possibility that an object A exists within the detection range RA set in step S51, and stores the position as a candidate position for the object A. On the other hand, if the peak of the processed signal is not equal to or greater than the determination threshold, the object determination unit 80 determines that an object A does not exist within the detection range RA set in step S51.

[0190] Then, in step S53, the phase control unit 51 determines whether or not the entire range of attachment positions identified in the second detection mode has been scanned. For example, as in this embodiment, it is assumed that two attachment positions are identified in the second detection mode. In this case, the phase control unit 51 determines whether or not the candidate position detection process has been executed in the third detection mode for each of these two attachment positions. If it is determined that the entire range of the identified attachment positions has been scanned, the process proceeds to step S55. If it is not determined that the entire range of the identified attachment positions has been scanned, the process proceeds to step S54.

[0191] In step S54, the phase control unit 51 changes the magnitude of the light projection phase difference Δω1 and the light reception phase difference Δω2 to change the light projection beam angle θ1 and the light reception beam angle θ2 within the range of the attachment position identified in the second detection mode. The phase control unit 51 changes the light projection beam angle θ1 and the light reception beam angle θ2 while maintaining the light projection beam diameter φ1 and the light reception beam diameter φ2 and maintaining the light projection intensity and light reception sensitivity in the second detection mode.

[0192] When performing a scanning cycle in the third detection mode, the phase control unit 51 controls the light projection phase difference Δω1 and the light reception phase difference Δω2 in this manner to change the light projection beam angle θ1 and the light reception beam angle θ2. This allows the phase control unit 51 to include the adhesion position identified by the object determination unit 80 in the scanning cycle executed in the second detection mode in the scanning range of the scanning cycle performed in the third detection mode.

[0193] The object determining unit 80 then repeats the processes of steps S52 to S54 until the candidate position detection process in the third detection mode is performed for the entire range of the object adhesion positions identified in the second detection mode. As a result, the laser radar device 1 changes the light projection beam angle θ1 and the light reception beam angle θ2 in the vertical and horizontal directions to scan the entire range of the object adhesion positions identified in the second detection mode, thereby performing the candidate position detection process in the third detection mode for the entire range.

[0194] In this embodiment, a first object A1 and a second object A2 are attached to the irradiation window 11, and two attachment positions are identified in the second detection mode. Therefore, the laser radar device 1 repeats the processes of steps S52 to S54 separately for only the attachment position identified in the second detection mode as the attachment position where the first object A1 is attached and the attachment position identified as the attachment position where the second object A2 is attached. Therefore, the scanning range in the third detection mode can be made smaller than when the candidate position detection process is performed for the entire range of the irradiation window 11, as in the first detection mode and the second detection mode. Then, the object determination unit 80 detects candidate positions in a range narrower than in the second detection mode.

[0195] If it is determined in step S53 that the entire range of adhesion positions identified in the second detection mode has been scanned, then in step S55, the phase control unit 51 determines whether scanning in the third detection mode has been performed the specified number of scans, as in step S40. That is, the phase control unit 51 determines whether a scanning cycle has been performed in the third detection mode.

[0196] If the phase control unit 51 determines that scanning in the third detection mode has been performed the number of scans, it proceeds to processing of step S57, and if it does not determine that scanning in the third detection mode has been performed the number of scans, it proceeds to processing of step S56.

[0197] In step S56, the phase control unit 51 returns the projecting beam angle θ1 and the receiving beam angle θ2 to the angles set in step S51 in order to again execute the candidate position detection process in the third detection mode for the entire range of attachment positions identified in the second detection mode. That is, the phase control unit 51 changes the projecting beam angle θ1 and the receiving beam angle θ2 so that the detection range RA is included in the range of attachment positions identified in the second detection mode.

[0198] Then, by repeatedly executing steps S52 to S54, the object determination unit 80 executes the candidate position detection process in the third detection mode for the entire range of attachment positions identified in the second detection mode, and again detects candidate positions of the object A. The object determination unit 80 changes the projecting beam angle θ1 and the receiving beam angle θ2 in the vertical and horizontal directions without changing the projecting beam diameter φ1 and the receiving beam diameter φ2, and executes the candidate position detection process in the third detection mode for the number of scans. As a result, information on the candidate positions of the object A detected in the third detection mode is stored in the object determination unit 80 for the number of scans or more.

[0199] Then, in step S57, the object determination unit 80 performs a position identification process similar to step S42 based on information about the candidate positions of object A detected multiple times or more in the third detection mode. That is, the object determination unit 80 identifies, among the stored candidate positions of object A detected multiple times or more, the candidate positions of object A that have been detected multiple times or more, and that have the number of determinations or more, as the object positions in the third detection mode. On the other hand, if the number of the same candidate positions is less than the predetermined number of determinations, the object determination unit 80 determines that object A is not attached to the candidate positions identified in the second detection mode.

[0200] Next, the phase control unit 51 determines whether or not a predetermined all-detection mode in the object detection mode has been executed. Specifically, it determines whether or not the first detection mode, the second detection mode, the third detection mode, and the fourth detection mode have been executed. If the phase control unit 51 determines that the predetermined all-detection mode has been executed, it proceeds to the processing of step S100. On the other hand, if the phase control unit 51 does not determine that the predetermined all-detection mode has been executed, it returns to the processing of step S50. In this embodiment, if the fourth detection mode has not been executed after the third detection mode has been executed, it returns to the processing of step S50.

[0201] In step S50, the phase control unit 51 sets the variation in the light projection phase difference Δω1 and the variation in the light reception phase difference Δω2 to the fourth detection mode. That is, the phase control unit 51 makes the light projection beam diameter φ1 smaller than the light projection beam diameter φ1 set in the third detection mode, so that the cross-sectional area perpendicular to a line extending along the light projection beam angle θ1 in the light projection range R1 is smaller than that in the third detection mode. Also, the phase control unit 51 makes the light reception beam diameter φ2 smaller than the light reception beam diameter φ2 set in the third detection mode, so that the cross-sectional area perpendicular to a line extending along the light reception beam angle θ2 in the light reception range R2 is smaller than that in the third detection mode. That is, the phase control unit 51 makes the detection range RA smaller than the detection range RA in the third detection mode.

[0202] In the next step S51, the phase control unit 51 changes the light projecting beam angle θ1 and the light receiving beam angle θ2 so that the detection range RA is included in the range of adhesion positions identified in the third detection mode. Then, in step S52, the object determination unit 80 executes the candidate position detection process again. That is, the object determination unit 80 executes the candidate position detection process in the fourth detection mode and determines whether or not there is a possibility that an object A exists within the detection range RA, which is set in step S51 and is narrower than the third detection mode, among the adhesion positions identified in the third detection mode.

[0203] Then, the laser radar device 1 repeatedly executes steps S52 to S54 in the fourth detection mode, similar to the processing in the third detection mode. Specifically, the phase control unit 51 changes the magnitude of the light projection phase difference Δω1 and the light reception phase difference Δω2 to change the light projection beam angle θ1 and the light reception beam angle θ2. The phase control unit 51 changes the light projection beam angle θ1 and the light reception beam angle θ2 while maintaining the light projection beam diameter φ1 and the light reception beam diameter φ2, so that the changed detection range RA falls within the range of the attachment position identified in the third detection mode. In other words, the phase control unit 51 changes the light projection beam angle θ1 and the light reception beam angle θ2 while maintaining the light projection intensity and the light reception sensitivity, so that the changed detection range RA falls within the range of the attachment position identified in the third detection mode.

[0204] When performing a scanning cycle in the fourth detection mode, the phase control unit 51 controls the light projection phase difference Δω1 and the light reception phase difference Δω2 in this manner to change the light projection beam angle θ1 and the light reception beam angle θ2. This allows the phase control unit 51 to include the adhesion position identified by the object determination unit 80 in the scanning cycle executed in the third detection mode in the scanning range of the scanning cycle performed in the fourth detection mode. Furthermore, the phase control unit 51 can gradually reduce the light projection beam diameter φ1 and the light reception beam diameter φ2 with each scanning cycle, and can change the light projection beam angle θ1 and the light reception beam angle θ2 so that the predetermined scanning range for each scanning cycle gradually decreases.

[0205] The laser radar device 1 changes the projection beam angle θ1 and the reception beam angle θ2 in the vertical and horizontal directions to scan the entire range of the adhesion positions identified in the third detection mode, thereby executing the candidate position detection process in the fourth detection mode for the entire range. The laser radar device 1 also repeats the processes of steps S52 to S54 separately for the adhesion positions identified in the third detection mode as having the first adhesion A1 and for the adhesion positions identified in the third detection mode as having the second adhesion A2. This allows the candidate position detection process in the fourth detection mode to have a smaller scanning range than when the candidate position detection process is executed in the third detection mode. The adhesion determining unit 80 then detects candidate positions in a narrower range than in the third detection mode.

[0206] If it is determined in step S53 that the entire range of adhesion positions identified in the third detection mode has been scanned, then in step S55 the phase control unit 51 determines whether scanning in the fourth detection mode has been performed the number of scans. That is, the phase control unit 51 determines whether a scanning cycle in the fourth detection mode has been performed. If the phase control unit 51 determines that scanning in the fourth detection mode has been performed the number of scans, it proceeds to processing in step S57, and if it does not determine that scanning in the fourth detection mode has been performed the number of scans, it proceeds to processing in step S56.

[0207] The laser radar device 1 repeatedly executes the processes of steps S52 to S56 until scanning in the fourth detection mode has been executed the number of scans. The object determination unit 80 performs the candidate position detection process in the fourth detection mode the number of scans by changing the projecting beam angle θ1 and the receiving beam angle θ2 in the vertical and horizontal directions without changing the projecting beam diameter φ1 and the receiving beam diameter φ2. As a result, information on the candidate position of the object A detected in the fourth detection mode is stored in the object determination unit 80 for the number of scans or more.

[0208] Then, in step S57, the object determination unit 80 performs a position identification process based on information about the candidate positions of object A detected multiple times or more in the fourth detection mode. That is, the object determination unit 80 identifies, among the stored candidate positions of object A detected multiple times or more, the candidate positions of object A that have been identified as the number of determinations or more as the object positions in the fourth detection mode. On the other hand, if the number of identical candidate positions is less than the predetermined number of determinations, the object determination unit 80 determines that object A is not attached to the candidate positions identified in the third detection mode.

[0209] If it is determined in step S34 that the processing in the full detection mode has been executed, then in step S100, the object determination unit 80 determines that an object A is attached to the irradiation window 11 and outputs the determination result to the vehicle control device. The object determination unit 80 also outputs information on the identified attachment position to the vehicle control device. Then, the processing in the object detection mode ends.

[0210] As described above, the phase control unit 51 of this embodiment can change the projection beam diameter φ1 by controlling the variation in the projection phase difference Δω1, and can change the reception beam diameter φ2 by controlling the variation in the reception phase difference Δω2. In the object detection mode, the phase control unit 51 gradually reduces the projection beam diameter φ1 and the reception beam diameter φ2 for each scanning cycle. Furthermore, the phase control unit 51 changes the projection beam angle θ1 and the reception beam angle θ2 for each scanning cycle so that the adhesion position identified by the object determination unit 80 for each scanning cycle is included in a predetermined scanning range for each scanning cycle, and so that the predetermined scanning range for each scanning cycle gradually decreases.

[0211] According to this, when scanning is repeated a certain number of times, the scanning range when scanning is performed can be limited, and therefore the time required for each scanning can be shortened.

[0212] (Modification of the sixth embodiment) In the sixth embodiment described above, an example has been described in which the object-determining unit 80 executes the same position specifying process as in the fourth embodiment in steps S42 and S57 to specify the location where the object A is attached, but the present invention is not limited to this. Specifically, as in the fourth embodiment, an example has been described in which the object-determining unit 80 specifies, as the attachment location, a candidate location of the object A that has been detected multiple times or more than the number of times determined, from among the candidate locations of the object A that have been detected multiple times or more. However, the present invention is not limited to this.

[0213] For example, in steps S42 and S57, the object determining unit 80 may identify the object having the object A by executing a position specifying process similar to that of the fifth embodiment. Specifically, when the average value of the peaks of a plurality of processed signals indicating the same candidate position among the stored candidate positions of the object A for a plurality of times or more is equal to or greater than a determination threshold, the object determining unit 80 may identify the candidate position as the object having the object A.

[0214] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0215] In the above embodiment, an example has been described in which the phase control unit 51 changes the light projection intensity and the light receiving sensitivity to make the detection distance in the object detection mode shorter than the detection distance in the normal mode, but this is not limiting. For example, the phase control unit 51 may change only one of the light projection intensity and the light receiving sensitivity to make the detection distance in the object detection mode shorter than the detection distance in the normal mode.

[0216] In the above embodiment, an example has been described in which the phase control unit 51 reduces the detection distance in the object detection mode compared to the detection distance in the normal mode by increasing the variation in the light-projection phase difference Δω1 and the variation in the light-reception phase difference Δω2 in the object detection mode compared to the normal mode, but this is not limiting. For example, the phase control unit 51 may reduce the detection distance in the object detection mode compared to the detection distance in the normal mode by increasing only one of the variation in the light-projection phase difference Δω1 and the variation in the light-reception phase difference Δω2 in the object detection mode compared to the normal mode.

[0217] In the above-described embodiment, an example in which the laser radar device 1 is applied to a vehicle has been described, but the present disclosure is not limited to this. The laser radar device 1 of the present disclosure may be installed in equipment other than a vehicle and configured to detect various objects T present around the various equipment in which the laser radar device 1 is installed.

[0218] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0219] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0220] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are fundamentally limited to specific shapes, positional relationships, etc.

[0221] The phase control unit 51 and the method thereof of the present disclosure may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. The phase control unit 51 and the method thereof of the present disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. The phase control unit 51 and the method thereof of the present disclosure may be implemented by one or more special-purpose computers configured by a combination of a processor and memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. [Explanation of symbols]

[0222] 10. Cabinet 11 Irradiation window 30 Transmitter 31 Transmitting Array 40 Receiving unit 41 Receiving Array 50 Light emission and reception control section 51 Phase control section 80 Adhesion detection unit

Claims

1. A laser radar device for detecting an object, a transmitting section (30) in which a plurality of transmitting arrays (31) for transmitting transmission waves are arranged side by side in a first direction; a receiving section (40) in which a plurality of receiving arrays (41) for receiving reflected waves are arranged side by side in a second direction; a housing (10) that houses the transmitting unit and the receiving unit and has an irradiation window (11) that transmits the transmitted wave and the reflected wave; a light emitting / receiving control unit (50) for controlling the operation of the transmitting unit and the receiving unit; a signal processing unit (60) that outputs a received signal according to the intensity of the reflected wave received by the receiving unit; an adhering matter determination unit (80) that determines whether or not an adhering matter is adhering to the irradiation window based on the received signal, The light emission and reception control unit is capable of switching the operation modes of the transmission unit and the reception unit between a normal mode for detecting the object and an object detection mode for detecting the object adhering to the irradiation window, and has a phase control unit (51) that changes the transmission intensity of the transmission wave when transmitted by the transmission unit by controlling the phase of each of the transmission waves transmitted by the multiple transmission arrays, and changes the reception sensitivity when the reception unit receives the reflected wave by controlling the phase of each of the reflected waves received by the multiple reception arrays, The phase control unit reduces at least one of the transmission intensity and the reception sensitivity in the object detection mode, thereby making the detection distance, which is the distance at which the object can be detected, shorter than the detection distance in the normal mode.

2. 2. The laser radar device according to claim 1, wherein the phase control unit, when defining a difference in phase between transmissions by adjacent transmitting arrays among the plurality of transmitting arrays aligned in the first direction as a light-projection phase difference and a difference in phase between the reflected waves received by adjacent receiving arrays among the plurality of receiving arrays aligned in the second direction as a light-receiving phase difference, increases at least one of the variations in the light-projection phase differences in the first direction and the variations in the light-receiving phase differences in the second direction in the object detection mode compared to the normal mode, thereby making the detection distance in the object detection mode smaller than the detection distance in the normal mode.

3. 3. The laser radar device according to claim 2, wherein the phase control unit controls the variation in the light projection phase difference to change the beam diameter of the transmitted wave in addition to the transmission intensity, and controls the variation in the light reception phase difference to change the beam diameter of the received wave when receiving the reflected wave in addition to the reception sensitivity, and makes the beam diameter of the transmitted wave in the object detection mode larger than the beam diameter of the received wave in the object detection mode.

4. the phase control unit controls the variation in the light projection phase difference to change the beam diameter of the transmitted wave and the transmission direction of the transmitted wave in addition to the transmission intensity, and controls the variation in the light reception phase difference to change the beam diameter of the received wave and the reception direction of the received wave when the received wave is received as the reflected wave in addition to the reception sensitivity, and in the object detection mode, when a scan is performed to detect the object within each predetermined scanning range, the phase control unit changes the transmission direction and the reception direction and gradually reduces the beam diameter of the transmitted wave and the beam diameter of the received wave for each scan, The laser radar device according to claim 2 , wherein the object determining unit detects an attachment position, which is a position of the object attached to the irradiation window, every time the scanning is performed.

5. the phase control unit is capable of changing the transmission direction of the transmission wave in addition to the transmission intensity by controlling the variation in the light projection phase difference, and changing the reception direction of the reflected wave in addition to the reception sensitivity by controlling the variation in the light reception phase difference, and in the object detection mode, when scanning for detecting the object for each predetermined scanning range is performed a predetermined number of times, the phase control unit changes the transmission direction and the reception direction while maintaining the transmission intensity and the reception sensitivity, 3. The laser radar device according to claim 2, wherein, when the scanning is performed the predetermined number of times and the plurality of reception signals are acquired from the signal processing unit, the adhesion determination unit detects a plurality of candidate positions of the adhesion position, which is the position of the adhesion position attached to the irradiation window, based on the plurality of acquired reception signals, and, when the number of candidate positions indicating the same position among the plurality of detected candidate positions is equal to or greater than a predetermined determination number, identifies the candidate positions with the number equal to or greater than the predetermined determination number as the adhesion position.

6. the phase control unit is capable of changing the transmission direction of the transmission wave in addition to the transmission intensity by controlling the variation in the light projection phase difference, and changing the reception direction of the reflected wave in addition to the reception sensitivity by controlling the variation in the light reception phase difference, and in the object detection mode, when scanning for detecting the object for each predetermined scanning range is performed a predetermined number of times, the phase control unit changes the transmission direction and the reception direction while maintaining the transmission intensity and the reception sensitivity, 3. The laser radar device according to claim 2, wherein, when the scanning is performed the predetermined number of times and the plurality of reception signals are acquired from the signal processing unit, the adhesion determination unit detects a plurality of candidate adhesion positions, which are positions of the adhesion on the irradiation window, based on the acquired plurality of reception signals, and, when an average value of peaks of a plurality of reception signals corresponding to each of the plurality of candidate adhesion positions indicating the same position among the detected plurality of candidate adhesion positions is equal to or greater than a predetermined determination threshold, identifies the candidate adhesion position detected based on the plurality of reception signals whose average peak value is equal to or greater than the predetermined determination threshold as the adhesion position.

7. the adhesion determination unit identifies the adhesion position for each scan cycle in which the scan is performed the predetermined number of times, 7. The laser radar device according to claim 5, wherein the phase control unit is capable of changing the beam diameter of the transmitted wave by controlling the variation in the light projection phase difference and of changing the beam diameter of the received wave when receiving the reflected wave by controlling the variation in the light reception phase difference, and in the object detection mode, gradually reduces the beam diameter of the transmitted wave and the beam diameter of the received wave for each scanning cycle and changes the transmission direction and the reception direction for each scanning cycle so that the object position identified by the object determination unit for each scanning cycle is included in the predetermined scanning range for each scanning cycle and the predetermined scanning range for each scanning cycle gradually reduces.

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