Sensor system

Abstract

The sensor system of the present invention suppresses the influence of a light-transmitting cover that allows light for detecting information outside a vehicle to pass through on the detection of information. A light-emitting element (41) emits detection light (L1) to the outside of the vehicle. A light-receiving element (42) outputs a light-receiving signal (S1) based on reflected light (L2). A processor (20) detects information outside the vehicle based on the light-receiving signal (S1). The light-transmitting cover (12) forms a part of the outer surface of the vehicle and has a plurality of flat portions (12a) that allow the detection light (L1) to pass through. The processor (20) excludes a position corresponding to a boundary portion (12b) of adjacent plurality of flat portions (12a) from the detection object of information.

Description

Technical Field

[0001] The present invention relates to a sensor system mounted on a vehicle. Background Art

[0002] In order to realize the driving assistance technology of a vehicle, it is necessary to install a sensor for detecting information outside the vehicle on the vehicle body. As an example of such a sensor, a LiDAR (Light Detection and Ranging) sensor can be cited (for example, refer to Patent Document 1).

[0003] The LiDAR sensor includes a light emitting element and a light receiving element. The light emitting element emits detection light to the outside of the vehicle. The detection light is reflected by an object located outside the vehicle and enters the light receiving element as reflected light. The light receiving element outputs a signal based on the reflected light. Based on the signal, information outside the vehicle is detected.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-185769 Summary of the invention

[0007] Technical problem that the invention aims to solve

[0008] In order to protect the LiDAR sensor from stains and flying stones, the LiDAR sensor is covered with a light-transmitting cover forming a part of the outer surface of the vehicle. Therefore, the above-mentioned detection light is emitted to the outside of the vehicle through the light-transmitting cover. The light-transmitting cover bends the detection light. As a result, a difference occurs between a point located on the extension line of the detection light incident on the light-transmitting cover and a point reached by the detection light emitted from the light-transmitting cover. This difference affects the detection of information on the outside of the vehicle.

[0009] An object of the present invention is to suppress the influence of a light-transmitting cover that allows passage of light for detecting information outside a vehicle on detection of information.

[0010] Technical solutions to the problem

[0011] Regarding the first scheme for achieving the above-mentioned purpose, a sensor system mounted on a vehicle is characterized in that it comprises: a light-emitting element, which emits detection light to the outside of the vehicle; a light-receiving element, which outputs a signal based on reflected light; a processor, which detects information about the outside of the vehicle based on the signal; and a light-transmitting cover, which forms a part of the outer surface of the vehicle and has multiple flat portions that allow the detection light to pass through, and the processor excludes positions corresponding to boundary portions of adjacent multiple flat portions from the detection objects of the information.

[0012] According to this configuration, since deflection of the detection light when passing through the light-transmitting cover can be reduced and positions corresponding to the boundary portions whose behavior is unpredictable can be excluded from the targets of information detection, the influence of the light-transmitting cover on information detection can be suppressed.

[0013] The sensor system according to the first aspect can be configured as follows.

[0014] The surface of the light-transmitting cover at the boundary portion is subjected to an opacification treatment at least with respect to the wavelength of the detection light.

[0015] According to this configuration, since the detection light can be configured not to pass through the boundary portion, it is possible to prevent the occurrence of unexpected behavior of the detection light due to the passage of the light-transmitting cover.

[0016] Regarding a second solution for achieving the above-mentioned purpose, a sensor system mounted on a vehicle is characterized in that it comprises: a light-emitting element that emits detection light to the outside of the vehicle; a light-receiving element that outputs a signal based on reflected light; a processor that detects information about the outside of the vehicle based on the signal; and a light-transmitting cover that forms a part of the outer surface of the vehicle and has a plurality of flat portions that allow the detection light to pass through, wherein the surface of the light-transmitting cover at the boundary portions of adjacent flat portions is subjected to at least an opacification treatment with respect to the wavelength of the detection light.

[0017] According to this configuration, since the detection light can be configured not to pass through the boundary portion, it is possible to prevent the occurrence of unexpected behavior of the detection light accompanying the passage of the light-transmitting cover. In this case, the position corresponding to the boundary portion can be excluded from the object of information detection without performing special processing on the processor side. In addition, since the bending of the detection light when passing through the light-transmitting cover can be reduced, the influence of the light-transmitting cover on the detection of information can be suppressed.

[0018] The sensor system according to the second aspect can be configured as follows.

[0019] A surface of the light-transmitting cover at the boundary portion is curved.

[0020] The area excluded from the object of information detection is preferably set to a minimum. Therefore, the area of ​​the opaque portion is preferably set to a minimum. The surface of the light-transmitting cover at the boundary portion is formed as a curved surface, so that the area of ​​the opaque portion is minimized and it is easy to apply opacification treatment. In addition, the formability of the light-transmitting cover (the degree of ease of pulling out from the mold, etc.) is improved.

[0021] The sensor system according to the first and second aspects can be configured as follows.

[0022] The light emitting element and the light receiving element are part of any one of a LiDAR sensor unit and a TOF sensor unit.

[0023] In this specification, a "sensor unit" refers to a component unit that has a desired information detection function and can be distributed as an individual component.

[0024] In this specification, "driving assistance" refers to at least a partial control process of driving operations (steering wheel operation, acceleration, deceleration), monitoring of the driving environment, and backup of driving operations. In other words, it includes content ranging from partial driving assistance to fully autonomous driving, such as collision damage mitigation braking function and lane keeping assist function. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The configuration of a left front sensor device according to one embodiment is shown.

[0026] Figure 2 express Figure 1 The location of the left front sensor device in the vehicle.

[0027] Figure 3 Indicates that it contains Figure 1 The composition of the sensor system including the left front sensor device.

[0028] Figure 4 A light-transmitting cover according to a comparative example is shown.

[0029] Figure 5 express Figure 3 Another example of a light-transmissive cover for a sensor system.

[0030] Figure 6 express Figure 1 Other configuration examples of the left front sensor device.

[0031] Figure 7 express Figure 6 The left front sensor unit is working.

[0032] Explanation of symbols

[0033] 1: sensor system, 12: light-transmitting cover, 12a: flat portion, 12b: boundary portion, 12c: opaque portion, 12d: curved surface, 14: LiDAR sensor unit, 41: light-emitting element, 42: light-receiving element, 20: processor, 100: vehicle, L1: detected light, L2: reflected light, S1: light-receiving signal DETAILED DESCRIPTION

[0034] Hereinafter, an example of the embodiment will be described in detail with reference to the drawings. In each of the drawings used in the following description, the scale is appropriately changed so that each component is made into a recognizable size.

[0035] In the accompanying drawings, arrow F indicates the front of the illustrated structure. Arrow B indicates the rear of the illustrated structure. Arrow U indicates the top of the illustrated structure. Arrow D indicates the bottom of the illustrated structure. Arrow L indicates the left of the illustrated structure. Arrow R indicates the right of the illustrated structure. The "left" and "right" used in the following description represent left and right directions as viewed from the driver's seat.

[0036] Figure 1 FIG. 2 shows a configuration of a left front sensor device 10 according to an embodiment. The left front sensor device 10 is disposed at Figure 2 The left front portion LF of the vehicle 100 is shown. The left front portion LF is a region located on the left side of the center of the vehicle 100 in the left-right direction and on the front side of the center of the vehicle 100 in the front-rear direction.

[0037] like Figure 1 As shown, the left front sensor device 10 includes a housing 11 and a light-transmitting cover 12. The housing 11 and the light-transmitting cover 12 define a storage chamber 13. The light-transmitting cover 12 forms a part of the outer surface of the vehicle 100.

[0038] The left front sensor device 10 includes a LiDAR sensor unit 14 . The LiDAR sensor unit 14 is disposed in the storage chamber 13 .

[0039] like Figure 3 As shown, the LiDAR sensor unit 14 includes a light emitting element 41 and a light receiving element 42. The light transmitting cover 12 covers the light emitting element 41 and the light receiving element 42.

[0040] The light emitting element 41 is configured to emit the detection light L1 to the outside of the vehicle 100. For example, infrared light with a wavelength of 905 nm can be used as the detection light L1. As the light emitting element 41, a semiconductor light emitting element such as a laser diode or a light emitting diode can be used.

[0041] The LiDAR sensor unit 14 may be appropriately provided with an optical system (not shown) for irradiating the detection light L1 in a desired direction. The LiDAR sensor unit 14 may be provided with a scanning device (not shown) for changing the irradiation direction of the detection light L1 and scanning the detection area.

[0042] The light receiving element 42 is configured to output a light receiving signal S1 corresponding to the amount of incident light. A photodiode, a phototransistor, or a photoresistor can be used as the light receiving element 42. The LiDAR sensor unit 14 may include an amplifier circuit (not shown) for amplifying the light receiving signal S1.

[0043] The light emitting element 41, the light receiving element 42 and the light transmissive cover 12 constitute the sensor system 1. The sensor system 1 further includes a processor 20. The processor 20 outputs a control signal S0 to the light emitting element 41 at a desired timing to cause the light emitting element 41 to emit the detection light L1. The processor 20 receives a light receiving signal S1 outputted from the light receiving element 42.

[0044] The processor 20 detects information outside the vehicle 100 based on the light receiving signal S1 corresponding to the reflected light L2. For example, the processor 20 can obtain the distance to the object associated with the reflected light L2 based on the time from the timing of emitting the detection light L1 in a certain direction to the time when the reflected light L2 is detected. In addition, by associating and integrating such distance data with the detection position, it is possible to obtain information related to the shape of the object associated with the reflected light L2. In addition to or instead of this, it is also possible to obtain information related to the properties of the material, etc. of the object associated with the reflected light L2 based on the difference in the waveforms of the detection light L1 and the reflected light L2.

[0045] The light-transmitting cover 12 has a plurality of flat portions 12a. The processor 20 is configured to exclude positions corresponding to the boundary portions 12b between the plurality of adjacent flat portions 12a from the detection target of information.

[0046] Figure 4 (A) shows the light-transmitting cover 12A and the light-emitting element 41A involved in the comparative example. In this example, the light-transmitting cover 12A has an arc-shaped cross section. The light-transmitting cover 12A and the light-emitting element 41A are configured so that the light emission center (light source position, scanning center, etc.) of the detection light L0 emitted from the light-emitting element 41A coincides with the curvature center of the arc shape.

[0047] According to this arrangement, the detection light L0 emitted from the light emitting element 41A can pass through the light transmissive cover 12A without bending regardless of its direction. However, the shape of the light transmissive cover 12A and the positional relationship of the light emitting element 41 are major constraints in designing the sensor device.

[0048] Moreover, if Figure 4As shown in (B), when the emission center of the detection light L0 and the curvature center of the arc shape are not consistent, the detection light L0 is greatly bent due to the curved surface of the light-transmitting cover 12A. That is, not only does the positioning of the components require high accuracy, but also the accuracy of information detection is easily affected by vibration and positional deviation caused by aging.

[0049] On the other hand, Figure 3 In the illustrated embodiment, the detection light L1 emitted from the light emitting element 41 is allowed to pass through the flat portion 12 a of the light-transmitting cover 12 .

[0050] According to this configuration, the detection light L1 can be easily incident perpendicularly to the light-transmitting cover 12. In this case, the detection light L1 will not be bent when passing through the light-transmitting cover 12. For example, Figure 3 The detection light L1A shown is incident perpendicularly to the translucent cover 12. Even if the translucent cover 12 and the light emitting element 41 are relatively displaced in the left-right direction from this state, the state in which the detection light L1A is incident perpendicularly to the translucent cover 12 can be maintained.

[0051] Moreover, if Figure 3 As shown in FIG. 1B , even if the detection light L1B is incident obliquely on the flat portion 12a, Figure 4 Compared with the case where the detection light L1B is incident on the curved surface shown in (B), the amount of deflection of the detection light L1B is smaller.

[0052] However, since a plurality of flat portions 12a are provided to obtain such an advantageous effect, a boundary portion 12b is inevitably formed between the plurality of adjacent flat portions 12a. At the boundary portion 12b, the behavior of the detection light L1C accompanying the passage of the light-transmitting cover 12 is unpredictable. Therefore, the processor 20 is configured not to detect information based on the reflected light L2 generated by the detection light L1C emitted toward the boundary portion 12b.

[0053] For example, when scanning is performed in which the emission direction of the detection light L1 changes periodically, the positional relationship between the light emitting element 41 and the boundary portion 12b is known, so the processor 20 can know in advance at what timing the emitted detection light is emitted toward the boundary portion 12b. Therefore, the processor 20 can be configured not to perform information detection processing based on the light receiving signal S1 corresponding to the reflected light generated by the detection light L1C emitted at that timing.

[0054] Alternatively, when a plurality of light emitting elements 41 emit detection light L1 in various directions, the positional relationship between the light emitting element 41 and the boundary portion 12b is also known, so the processor 20 can know in advance from which direction the detection light emitted by the element 41 is emitted toward the boundary portion 12b. Therefore, the processor 20 can be configured not to perform information detection processing based on the detection signal S1 corresponding to the reflected light generated by the detection light L1C emitted from the light emitting element 41.

[0055] Since the deflection of the detection light L1 when passing through the light-transmitting cover 12 can be reduced and the position corresponding to the boundary portion 12 b whose behavior is unpredictable can be excluded from the target of information detection, the influence of the light-transmitting cover 12 on the detection of information can be suppressed.

[0056] Figure 5 (A) Figure 3 The boundary portion 12b of the light-transmitting cover 12 surrounded by the dashed line V in FIG. 1 is enlarged and shown. The surface of the light-transmitting cover 12 at the boundary portion 12b can be set as an opaque portion 12c, and the opaque portion 12c is subjected to an opacification treatment at least for the wavelength of the detection light L1. Examples of the opacification treatment include a treatment in which the surface is set to be frosted glass-like by forming fine concavo-convex portions, a treatment in which a coating is applied to the surface, and the like.

[0057] According to this configuration, since the detection light L1 can be configured not to pass through the boundary portion 12b, it is possible to prevent the occurrence of unexpected behavior of the detection light L1 accompanying the passage of the light-transmitting cover 12. In this case, the processor 20 side does not need to perform special processing, and the position corresponding to the boundary portion 12b can be excluded from the target of information detection.

[0058] Since the deflection of the detection light L1 when passing through the translucent cover 12 can be reduced and the position corresponding to the boundary portion 12b whose behavior is unpredictable can be excluded from the target of information detection, the influence of the translucent cover 12 on the detection of information can be suppressed.

[0059] like Figure 5 As shown in (B), the surface of the light-transmitting cover 12 at the boundary portion 12b may be formed as a curved surface 12d.

[0060] The area excluded from the object of information detection is preferably set to a minimum. Therefore, the area of ​​the opaque portion 12c is preferably set to a minimum. The surface of the light-transmitting cover 12 at the boundary portion 12b is formed as a curved surface 12d, so that the area of ​​the opaque portion 12c is minimized, and it is easy to apply opacification. In addition, the formability of the light-transmitting cover 12 (the degree of ease of extraction from the mold, etc.) is improved.

[0061] The functions of the processor 20 described above may be implemented using a general-purpose microprocessor that works in cooperation with a memory, or may be implemented using a dedicated integrated circuit such as a microcontroller, FPGA, or ASIC.

[0062] The processor 20 may be disposed at any position of the vehicle. The processor 20 may be provided as a part of a main ECU that is responsible for the central control processing of the vehicle, or may be provided as a part of a sub-ECU that exists between the main ECU and the LiDAR sensor unit 14 .

[0063] like Figure 1 As shown in the figure, the left front sensor device 10 may include a lamp unit 15. The lamp unit 15 is arranged in the storage chamber 13. The lamp unit 15 can irradiate visible light to the outside of the vehicle 100. As the lamp unit 15, a headlamp unit, a width lamp unit, a turn signal lamp unit, a fog lamp unit, etc. can be exemplified. Here, the "lamp unit" refers to a component unit that has a desired lighting function and can be distributed as an individual.

[0064] The light unit 15 is generally arranged at the four corners of the vehicle 100. The four corners are also positions where there are few obstacles when detecting information outside the vehicle 100. By configuring the LiDAR sensor unit 14 so as to have both the light unit 15 and the storage chamber 13, it is possible to efficiently detect information outside the vehicle 100.

[0065] The left front sensor device 10 may include a sensor bracket 43 and a lamp bracket 53. The sensor bracket 43 and the lamp bracket 53 are independent of each other. The LiDAR sensor unit 14 is supported by the sensor bracket 43. The lamp unit 15 is supported by the lamp bracket 53.

[0066] The left front sensor device 10 may include a sensor aiming mechanism 44 and a light aiming mechanism 54. The sensor aiming mechanism 44 is a mechanism for adjusting the detection reference direction of the LiDAR sensor unit 14. The light aiming mechanism 54 is a mechanism for adjusting the illumination reference direction of the light unit 15.

[0067] The sensor alignment mechanism 44 includes a first screw 441 and a second screw 442. The first screw 441 and the second screw 442 are provided so as to be operable from the outside of the housing 11.

[0068] When the first screw 441 is operated, the posture of the sensor bracket 43 changes in the left-right direction with the fulcrum not shown as the center. As a result, the detection reference direction of the LiDAR sensor unit 14 changes in the left-right direction. When the second screw 442 is operated, the posture of the sensor bracket 43 changes in the up-down direction with the fulcrum not shown as the center. As a result, the detection reference direction of the LiDAR sensor unit 14 changes in the up-down direction. The first screw 441 and the second screw 442 can be replaced by actuators that operate according to control signals from the outside.

[0069] The lamp aiming mechanism 54 includes a first screw 541 and a second screw 542. The first screw 541 and the second screw 542 are provided so as to be operable from the outside of the housing 11.

[0070] When the first screw 541 is operated, the posture of the lamp bracket 53 changes in the left-right direction with the fulcrum not shown as the center. As a result, the detection reference direction of the lamp unit 15 changes in the left-right direction. When the second screw 542 is operated, the posture of the lamp bracket 53 changes in the up-down direction with the fulcrum not shown as the center. As a result, the detection reference direction of the lamp unit 15 changes in the up-down direction. The first screw 541 and the second screw 542 can be replaced by actuators that work according to control signals from the outside.

[0071] Or, if Figure 6 As shown, the left front sensor device 10 may include a common bracket 16 . The LiDAR sensor unit 14 and the light unit 15 are supported by the bracket 16 .

[0072] In this case, the left front sensor device 10 may include a screw actuator 55. The screw actuator 55 may be controlled by the processor 20. Figure 7 As shown in (A), the screw actuator 55 changes the illumination reference direction of the lamp unit 15 in the left-right direction by rotating the bracket 16 around the rotation axis 16a.

[0073] The detection reference direction of the LiDAR sensor unit 14 supported by the common bracket 16 also changes in the same direction. Since the LiDAR sensor unit 14 has a relatively wide detectable range in the left-right direction, even if the detection reference direction changes, the influence on the detection of information is relatively small.

[0074] However, if the detection reference direction of the LiDAR sensor unit 14 needs to be precisely adjusted, Figure 6 As shown in FIG. 1 , the left front sensor device 10 may include a screw actuator 45. The screw actuator 45 may be controlled by the processor 20. The screw actuator 45 rotates the LiDAR sensor unit 14 around the rotation axis 16 b, thereby Figure 7As shown in FIG. 5B , the detection reference direction of the LiDAR sensor unit 14 is changed to the left and right direction. This can cancel out the influence of the screw actuator 55 on the rotation of the bracket 16 .

[0075] Since the range that the LiDAR sensor unit 14 can detect in the vertical direction is relatively small, the left front sensor device 10 preferably independently includes a leveling actuator 46 and a leveling actuator 56. The leveling actuator 46 changes the detection reference direction of the LiDAR sensor unit 14 in the vertical direction. The leveling actuator 56 changes the detection reference direction of the light unit 15 in the vertical direction.

[0076] The above-described embodiments are merely examples for facilitating understanding of the present invention, and the configurations of the above-described embodiments may be appropriately changed or improved without departing from the spirit of the present invention.

[0077] The LiDAR sensor unit 14 can also be replaced by a TOF (Time of Flight) camera unit. The TOF camera unit includes a light emitting element and a light receiving element. The detection light emitted from the light emitting element is reflected by an object located outside the vehicle, and is incident on the light receiving element as reflected light. Based on the time from the emission of the detection light from the light emitting element to the incidence of the reflected light on the light emitting element, the distance to the object is calculated. While scanning the detection light two-dimensionally, the calculated distance is associated with each pixel of the two-dimensional image acquired by the camera, so that information related to the shape of the object can be obtained.

[0078] exist Figure 2 The right front RF of the vehicle 100 shown may be equipped with Figure 1 The left front sensor device 10 shown is a right front sensor device with a bilaterally symmetrical structure. The right front portion RF is a region located to the right of the center in the left-right direction of the vehicle 100 and to the front of the center in the front-rear direction of the vehicle 100 .

[0079] The structure of the left front sensor device 10 is also applicable to the left rear sensor device. The left rear sensor device is mounted on Figure 2 The left rear portion LB of the vehicle 100 shown in the figure is located to the left of the left-right center of the vehicle 100 and to the rear of the front-rear center of the vehicle 100. The basic structure of the left rear sensor device can be symmetrical with the left front sensor device 10.

[0080] The structure of the left front sensor device 10 is also applicable to the right rear sensor device. The right rear sensor device is mounted on Figure 2The right rear portion RB of the vehicle 100 shown in the figure is an area located to the right of the left-right center of the vehicle 100 and to the rear of the front-rear center of the vehicle 100. The basic structure of the right rear sensor device can be bilaterally symmetrical with the above-mentioned left rear sensor device.

Claims

1. A sensor system mounted on a vehicle, characterized in that: have: a light emitting element that emits detection light to the outside of the vehicle; a light receiving element, wherein the detection light is reflected outside the vehicle to become reflected light, and the light receiving element outputs a signal based on the reflected light; a processor configured to detect information external to the vehicle based on the signal; as well as a light-transmitting cover forming a part of the outer surface of the vehicle and having a plurality of flat portions allowing the detection light to pass therethrough, The processor excludes a position corresponding to a boundary portion of the plurality of adjacent flat portions from a detection target of the information.

2. The sensor system of claim 1, wherein: The surface of the light-transmitting cover at the boundary portion is subjected to an opacifying treatment so as to be opaque at least with respect to the wavelength of the detection light.

3. The sensor system of claim 1, wherein: A surface of the light-transmitting cover at the boundary portion is curved.

4. The sensor system of claim 2, wherein: A surface of the light-transmitting cover at the boundary portion is curved.

5. A sensor system mounted on a vehicle, characterized in that: have: a light emitting element that emits detection light to the outside of the vehicle; a light receiving element, wherein the detection light is reflected outside the vehicle to become reflected light, and the light receiving element outputs a signal based on the reflected light; a processor configured to detect information external to the vehicle based on the signal; as well as a light-transmitting cover forming a part of the outer surface of the vehicle and having a plurality of flat portions allowing the detection light to pass therethrough, The surface of the light-transmitting cover at the boundary portion between the adjacent flat portions is subjected to at least an opacifying treatment to be opaque to the wavelength of the detection light.

6. The sensor system of claim 5, wherein: A surface of the light-transmitting cover at the boundary portion is curved.

7. The sensor system according to any one of claims 1 to 6, wherein: The light emitting element and the light receiving element are part of any one of a LiDAR sensor unit and a TOF camera unit.

8. The sensor system of claim 5, wherein: When performing scanning in which the emission direction of the detection light changes periodically, the processor is configured to perform information detection processing not based on the signal corresponding to the reflected light generated by the detection light emitted at a predetermined timing, utilizing the positional relationship between the light emitting element and the boundary portion.

9. The sensor system of claim 5, wherein: When the plurality of light-emitting elements emit the detection light in various directions, the processor is configured to perform information detection processing not based on the signal corresponding to the reflected light generated by the detection light emitted from the predetermined light-emitting element, utilizing the positional relationship between the light-emitting element and the boundary portion.

10. The sensor system of claim 7, wherein: The processor is arranged at any position of the vehicle. The processor is provided as a part of a main ECU that undertakes central control processing of the vehicle, or is provided as a part of a sub-ECU existing between the main ECU and the LiDAR sensor unit.

11. The sensor system of claim 7, wherein: A sensor alignment mechanism is also provided, and the sensor alignment mechanism is used to adjust the detection reference direction of the LiDAR sensor unit.

12. The sensor system of claim 11, wherein: The sensor alignment mechanism includes a first screw and a second screw, When the first screw is operated, the detection reference direction of the LiDAR sensor unit changes to the left and right direction. When the second screw is operated, the detection reference direction of the LiDAR sensor unit changes to the up-down direction.

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