Sensor system, vehicle control method, and vehicle

Abstract

A sensor system (20) to be mounted on a vehicle (1) that can travel in an automated driving mode, the system comprising: a sensor (6) that obtains information about the outside of the vehicle (1); an anomaly determination unit (21) that determines, on the basis of a detection result of the sensor (6), if an anomaly caused by a scratch or smudge is generated; and a vehicle speed-limit setting unit (22) that outputs, to the vehicle (1), a first maximum vehicle speed signal indicating a first maximum vehicle speed in the automated driving mode, on the basis of a determination result of the anomaly determination unit (21).

Description

[Technical Field]

[0001] The present invention relates to a sensor system, a vehicle control method, and a vehicle. [Background technology]

[0002] A cleaner system equipped with a cleaner is known from Patent Document 1 and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication WO2019 / 172159 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, when dirt adheres to the sensor, a cleaner is activated to attempt to remove the dirt, and if the dirt still does not come off, the system switches from autonomous driving mode to manual driving mode. However, this configuration prevents the vehicle from driving in autonomous driving mode if even a small amount of dirt cannot be removed, and it is expected that situations in which autonomous driving mode is not possible will frequently occur. In other words, it is expected that there will be situations in which the sensor's original detection sensitivity is not achieved, such as when sensing is not impaired over short distances, but this does not interfere with the execution of autonomous driving mode at low speeds. By taking such situations into consideration, we realized that there is room to further extend the distance that can be driven in autonomous driving mode.

[0005] Therefore, the present invention provides a sensor system, a vehicle control method, and a vehicle that can ensure a long distance traveled in autonomous driving mode. [Means for solving the problem]

[0006] A sensor system according to one aspect of the present invention includes: A sensor system mounted on a vehicle capable of running in an autonomous driving mode. a sensor for acquiring information about the outside of the vehicle; an abnormality determination unit that determines whether an abnormality caused by a scratch or dirt has occurred based on the detection result of the sensor; A sensor system having a vehicle speed limit setting unit that outputs a first maximum vehicle speed signal indicating a first maximum vehicle speed in the autonomous driving mode to the vehicle depending on the judgment result of the abnormality judgment unit.

[0007] If mud or other factors cause abnormalities in the sensor detection results, making it impossible to ensure the reliability of the external sensor, the vehicle control unit may find it difficult to execute the autonomous driving mode. However, if the sensor detection results are not completely reliable but still provide reasonable detection results, it may be difficult to execute the autonomous driving mode at normal speeds, but it may be possible to execute the autonomous driving mode at speeds slower than normal. Therefore, in the present invention, when the abnormality determination unit determines that mud or other factors have caused an abnormality in the sensor detection results, the vehicle speed limit setting unit outputs a maximum vehicle speed signal to the vehicle control unit, thereby enabling the vehicle control unit to execute the autonomous driving mode at a speed below the first maximum vehicle speed. This allows the vehicle to travel a longer distance in autonomous driving mode.

[0008] A vehicle control method according to one aspect of the present invention includes: A method for controlling a vehicle capable of running in an autonomous driving mode using a sensor system including a sensor that acquires information about the outside of the vehicle and an abnormality determination unit that determines whether an abnormality due to a scratch or dirt has occurred in a detection result of the sensor, A first maximum vehicle speed in the autonomous driving mode is set according to a determination result of the abnormality determination unit.

[0009] If mud or other factors cause abnormalities in the sensor detection results, making it impossible to ensure the reliability of the external sensors, the vehicle control unit will find it difficult to execute the autonomous driving mode. However, if the sensor detection results are not completely reliable but still provide reasonable detection results, it may be difficult to execute the autonomous driving mode at normal speeds, but it may be possible to execute the autonomous driving mode at speeds slower than normal. Therefore, in the present invention, when the abnormality determination unit determines that an abnormality has occurred in the sensor detection results due to mud or other factors, the maximum vehicle speed in the autonomous driving mode is set according to the determination result of the abnormality determination unit. This allows the vehicle to travel a long distance in the autonomous driving mode.

[0010] A vehicle according to one aspect of the present invention includes: An autonomously driven vehicle, an autonomous driving execution unit that drives the vehicle in an autonomous driving mode; a sensor for acquiring information about the outside of the vehicle; an abnormality determination unit that determines whether an abnormality caused by a scratch or dirt has occurred in the detection result of the sensor; The vehicle speed limit setting unit generates a first maximum vehicle speed signal indicating a first maximum vehicle speed in the autonomous driving mode in accordance with a determination result of the abnormality determination unit.

[0011] If mud or other factors cause abnormalities in the sensor detection results, making it impossible to ensure the reliability of the external sensor, the vehicle control unit may find it difficult to execute the autonomous driving mode. However, if the sensor detection results are not completely reliable but still provide reasonable detection results, it may be difficult to execute the autonomous driving mode at normal speeds, but it may be possible to execute the autonomous driving mode at speeds slower than normal. Therefore, in the present invention, when the abnormality determination unit determines that mud or other factors have caused an abnormality in the sensor detection results, the vehicle speed limit setting unit outputs a maximum vehicle speed signal to the vehicle control unit, thereby enabling the vehicle control unit to execute the autonomous driving mode at a speed below the first maximum vehicle speed. This allows the vehicle to travel a longer distance in autonomous driving mode. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a system block diagram of a vehicle. [Figure 2] FIG. [Figure 3] This shows an image captured by the camera under normal conditions. [Figure 4] The image captured by the camera when an abnormality occurs is shown. [Figure 5] 10 is a flowchart of a process executed by a vehicle speed limit setting unit. [Figure 6] 10 is a flowchart of a method according to a modified example of the present invention, which is executed by a vehicle speed limit setting unit. [Figure 7] FIG. 10 is a system block diagram of a vehicle according to a first modified example of the present invention. [Figure 8] FIG. 10 is a system block diagram of a vehicle according to a second modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the sake of convenience, the description of components having the same reference numerals as those already described in the description of the embodiments will be omitted. Furthermore, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0014] Furthermore, in the description of this embodiment, for the sake of convenience, the terms "left-right direction," "front-rear direction," and "up-down direction" will be referred to as appropriate. These directions are relative directions set for the vehicle. Here, the "up-down direction" is a direction that includes the "upward direction" and the "downward direction." The "front-rear direction" is a direction that includes the "forward direction" and the "rearward direction." The "left-right direction" is a direction that includes the "leftward direction" and the "rightward direction."

[0015] First, a vehicle system 2 of a vehicle 1 will be described with reference to Fig. 1. The vehicle 1 is equipped with a vehicle system 2. In the first embodiment, the vehicle 1 is an automobile that can run in an autonomous driving mode. Fig. 1 is a system block diagram of a vehicle 1. As shown in Fig. 1, a vehicle system 2 includes a vehicle control unit 3, an internal sensor 5, lamps 7, an HMI (Human Machine Interface) 8, a GPS (Global Positioning System) 9, a wireless communication unit 10, and a map information storage unit 11. Furthermore, the vehicle system 2 includes a steering actuator 12, a steering device 13, a brake actuator 14, a brake device 15, an accelerator actuator 16, and an accelerator device 17.

[0016] The vehicle control unit 3 is configured with an electronic control unit (ECU). The vehicle control unit 3 is configured with a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory) in which various vehicle control programs are stored, and a RAM (Random Access Memory) in which various vehicle control data are temporarily stored. The processor is configured to load a program specified from the various vehicle control programs stored in the ROM onto the RAM and execute various processes in cooperation with the RAM. The vehicle control unit 3 is configured to control the running of the vehicle 1.

[0017] The internal sensor 5 is a sensor capable of acquiring information about the vehicle itself. The internal sensor 5 is, for example, at least one of an acceleration sensor, a speed (vehicle speed) sensor, a wheel speed sensor, and a gyro sensor. The internal sensor 5 is configured to acquire information about the vehicle itself, including the traveling state of the vehicle 1, and output the information to the vehicle control unit 3. The internal sensor 5 may include a seating sensor that detects whether the driver is sitting in the driver's seat, a face direction sensor that detects the direction of the driver's face, a human presence sensor that detects whether there is a person in the vehicle, and the like.

[0018] The lamps 7 are at least one of headlamps or position lamps provided at the front of the vehicle 1, rear combination lamps provided at the rear of the vehicle 1, turn signal lamps provided at the front or sides of the vehicle, and various other lamps that inform pedestrians and drivers of other vehicles of the vehicle's situation.

[0019] The HMI 8 is composed of an input unit that accepts input operations from the driver and an output unit that outputs driving information, etc. to the driver. The input unit includes a steering wheel, an accelerator pedal, a brake pedal, a driving mode changeover switch that changes the driving mode of the vehicle 1, etc. The output unit is a display that displays various driving information.

[0020] The GPS 9 is configured to acquire current position information of the vehicle 1 and output the acquired current position information to the vehicle control unit 3. The wireless communication unit 10 is configured to receive driving information of other vehicles around the vehicle 1 from the other vehicles and transmit driving information of the vehicle 1 to the other vehicles (vehicle-to-vehicle communication). The wireless communication unit 10 is also configured to receive infrastructure information from infrastructure facilities such as traffic lights and marker lights and transmit driving information of the vehicle 1 to the infrastructure facilities (road-to-vehicle communication). The map information storage unit 11 is an external storage device such as a hard disk drive that stores map information, and is configured to output the map information to the vehicle control unit 3.

[0021] When the vehicle 1 is traveling in the autonomous driving mode, the vehicle control unit 3 automatically generates at least one of a steering control signal, an accelerator control signal, and a brake control signal based on traveling state information, surrounding environment information, current position information, map information, etc. The steering actuator 12 is configured to receive the steering control signal from the vehicle control unit 3 and control the steering device 13 based on the received steering control signal. The brake actuator 14 is configured to receive the brake control signal from the vehicle control unit 3 and control the brake device 15 based on the received brake control signal. The accelerator actuator 16 is configured to receive the accelerator control signal from the vehicle control unit 3 and control the accelerator device 17 based on the received accelerator control signal. In this way, in the autonomous driving mode, the traveling of the vehicle 1 is automatically controlled by the vehicle system 2.

[0022] On the other hand, when the vehicle 1 is driven in the manual driving mode, the vehicle control unit 3 generates a steering control signal, an accelerator control signal, and a brake control signal in accordance with the driver's manual operation of the accelerator pedal, the brake pedal, and the steering wheel. In this way, in the manual driving mode, the steering control signal, the accelerator control signal, and the brake control signal are generated by the driver's manual operation, so that the driving of the vehicle 1 is controlled by the driver.

[0023] Next, the driving modes of the vehicle 1 will be described. The driving modes include an autonomous driving mode and a manual driving mode. The autonomous driving modes include a fully autonomous driving mode, an advanced driving assistance mode, and a driving assistance mode. In the fully autonomous driving mode, the vehicle system 2 automatically performs all driving control, including steering control, braking control, and accelerator control, and the driver is not in a state where he or she can drive the vehicle 1. In the advanced driving assistance mode, the vehicle system 2 automatically performs all driving control, including steering control, braking control, and accelerator control, and the driver is in a state where he or she can drive the vehicle 1 but does not drive the vehicle 1. In the driving assistance mode, the vehicle system 2 automatically performs some driving control, including steering control, braking control, and accelerator control, and the driver drives the vehicle 1 with the driving assistance of the vehicle system 2. On the other hand, in the manual driving mode, the vehicle system 2 does not automatically perform driving control, and the driver drives the vehicle 1 without the driving assistance of the vehicle system 2.

[0024] The driving mode of the vehicle 1 may also be switched by operating a driving mode selector switch. In this case, the vehicle control unit 3 switches the driving mode of the vehicle 1 among four driving modes (fully automated driving mode, advanced driving assistance mode, driving assistance mode, and manual driving mode) in response to the driver's operation of the driving mode selector switch. The driving mode of the vehicle 1 may also be automatically switched based on information about drivable sections where autonomous vehicles are allowed to drive and prohibited sections where autonomous vehicles are prohibited from driving, or information about external weather conditions. In this case, the vehicle control unit 3 switches the driving mode of the vehicle 1 based on this information. Furthermore, the driving mode of the vehicle 1 may also be automatically switched using a seating sensor, a face direction sensor, or the like, which are internal sensors 5. In this case, the vehicle control unit 3 switches the driving mode of the vehicle 1 based on output signals from the seating sensor and the face direction sensor.

[0025] 1, the vehicle system 2 further includes a sensor system 20. The sensor system 20 includes an external sensor 6 (sensor), an abnormality determination unit 21, a vehicle speed limit setting unit 22, a driving mode acquisition unit 23, a cleaner 24, and a cleaner control unit 25.

[0026] The external sensor 6 is a sensor capable of acquiring information about the outside of the vehicle 1. The external sensor 6 is, for example, at least one of a camera, a radar, a LiDAR, a gating camera, etc. The external sensor 6 is configured to acquire information about the outside of the vehicle 1, including the surrounding environment of the vehicle 1 (other vehicles, pedestrians, road shapes, traffic signs, obstacles, etc.), and output the information to the vehicle control unit 3. Alternatively, the external sensor 6 may include a weather sensor that detects weather conditions, an illuminance sensor that detects the illuminance of the surrounding environment of the vehicle 1, etc. The external sensor 6 is configured to acquire information about at least one of the areas in front of, beside, and behind the vehicle 1.

[0027] The camera is a camera including an imaging element 31 such as a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor). The camera may be a camera that detects visible light, an infrared camera that detects infrared light, or a gating camera (range gate camera). The radar may be a millimeter wave radar, a microwave radar, or the like. LiDAR is an abbreviation for Light Detection and Ranging or Laser Imaging Detection and Ranging. LiDAR is a sensor that generally emits invisible light in front of it and acquires information such as the distance to an object, the shape of the object, the material of the object, and the color of the object based on the emitted light and the returned light. In the following description, the present embodiment will be described by taking a camera as an example of the external sensor 6.

[0028] The driving mode acquisition unit 23 acquires an autonomous driving signal indicating that the vehicle 1 is driving in the autonomous driving mode from the vehicle control unit 3. In other words, when the vehicle 1 is driving in the autonomous driving mode, the driving mode acquisition unit 23 acquires the autonomous driving signal from the vehicle control unit 3.

[0029] The cleaner 24 is a device that sprays a cleaning medium such as air or water onto mud and dust adhering to the external sensor 6 to clean the area detected by the external sensor 6, or a device that operates a wiper to clean the area detected by the external sensor 6. The cleaner control unit 25 controls the operation of this cleaner 24 based on a command from the vehicle speed limit setting unit 22.

[0030] Fig. 2 is a cross-sectional view of camera 6. As shown in Fig. 2, camera 6 includes an image sensor 31, a substrate 32 on which image sensor 31 is mounted, an inner lens 33 that focuses external light onto image sensor 31, an outer cover 34, and a housing 35. Outer cover 34 is a transparent member, and forms an enclosed space together with housing 35. Image sensor 31, substrate 32, and inner lens 33 are housed within this enclosed space.

[0031] The abnormality determination unit 21 determines, based on the detection result of the external sensor 6, that an abnormality caused by a scratch or dirt has occurred. Specifically, dirt, dust, leaves, insects, and the like may adhere to the outer cover 34. Scratches and cracks may occur on the outer cover 34 due to contact with obstacles or flying stones, or due to deterioration over time. Cracks may also occur in the inner lens 33 due to deterioration over time. Clouding may occur on the inner surface of the inner lens 33, or water droplets may adhere to the inner surface. Deformation may occur inside the inner lens 33 due to temperature changes or stress, and this deformation may affect polarization, reducing the output of the linearly polarized laser light. Light incident on the imaging element 31 from the outside passes through the outer cover 34 and the inner lens 33. If the outer cover 34 or the inner lens 33 is scratched or dirty, the detection results of the camera 6 will be abnormal.

[0032] Fig. 3 shows an image captured by the camera 6 under normal conditions, when there are no scratches or dust on the outer cover 34 or inner lens 33. Fig. 4 shows an image captured by the camera 6 under abnormal conditions, when mud has adhered to the outer cover 34. Note that for convenience of drawing, the pixels 41 are drawn much coarser in Figs. 3 and 4 than they actually are.

[0033] As shown in FIGS. 3 and 4 , in this embodiment, the camera 6 forms an image 40 consisting of a plurality of pixels 41. The camera 6 decomposes a predetermined area within the angle of view of the camera 6 of the vehicle 1 into arbitrary infinitesimal elements, and collects information such as the wavelength (color) of light arriving from each infinitesimal element and the intensity of the light at that wavelength using each corresponding image sensor 31. The information about the infinitesimal element acquired by one image sensor 31 is output as a pixel 41. For example, the pixel 41 includes information such as luminance and color according to the brightness and wavelength of light acquired by the image sensor 31. The camera generates an image 40 by integrating the pixels 41 output by each image sensor 31, and outputs the generated image 40 to the vehicle control unit 3.

[0034] Normally, while the vehicle 1 is traveling, the situation ahead of the vehicle 1 changes, and the information about the light incident on the camera 6 should change continuously. However, for example, if mud adheres to the outer cover 34, the mud blocks the light that would normally be incident on a specific image sensor 31. Therefore, even while the vehicle 1 is traveling, the information about the minute element output by the specific image sensor 31 does not change, and no change occurs in the pixel 41 corresponding to the minute element. In FIG. 4, a pixel with an abnormality in the detection result is indicated by the symbol D. Therefore, the abnormality determination unit 21 determines whether or not an abnormality has occurred in the detection result of the minute element based on whether or not the change in the information about the minute element is equal to or less than a predetermined threshold value over a predetermined time while the vehicle 1 is traveling. In this example, if the change in the information about the minute element (change in pixel) is equal to or less than the predetermined threshold value over a predetermined time while the vehicle 1 is traveling, the abnormality determination unit 21 determines that an abnormality has occurred in the detection result of the minute element.

[0035] The abnormality determination unit 21 does not determine abnormalities in the external sensor 6 that are caused by abnormalities in the electrical circuits that constitute the external sensor 6. The abnormality determination unit 21 herein determines abnormalities in the external sensor 6 that are caused by scratches, cracks, dust, mud, sand, water, insects, leaves, etc. adhering to optical members that constitute the external sensor 6, such as the outer cover 34 and inner lens 33.

[0036] The same applies when the external sensor 6 is a LiDAR. A LiDAR also breaks down a predetermined area within the field of view outside the vehicle 1 into arbitrary infinitesimal elements, irradiates each infinitesimal element with a laser, and collects information such as the reflection intensity, frequency, and return time (TOF (time of flight)) of the reflected wave. The LiDAR includes a transmitter that emits a laser, a receiver that receives the laser reflected off an object in front of the LiDAR, and a housing and outer cover that accommodate the transmitter and receiver. If the outer cover becomes soiled with mud, dust, or scratches, the information obtained from a specific infinitesimal area will not change even while the vehicle 1 is traveling. Therefore, the abnormality determination unit 21 determines that an abnormality has occurred in the detection result of the infinitesimal element if the change in the information obtained from the infinitesimal element over a predetermined time period is below a predetermined threshold, even while the vehicle 1 is traveling.

[0037] The same applies when the external sensor 6 is a millimeter-wave radar. A millimeter-wave radar also breaks down a predetermined area within the field of view outside the vehicle 1 into arbitrary infinitesimal elements, irradiates each infinitesimal element with millimeter waves, and collects information such as the reflection intensity, frequency, and time of return (TOF) of the reflected waves. The millimeter-wave radar includes a transmitter that emits millimeter waves, a receiver that receives millimeter waves reflected from objects in front of the millimeter-wave radar, and a housing and outer cover that accommodate the transmitter and receiver. If the outer cover becomes dirty with mud, dust, or scratches, the information obtained from a specific infinitesimal area will not change even while the vehicle 1 is moving. Therefore, the abnormality determination unit 21 determines that an abnormality has occurred in the detection result of the infinitesimal element if the change in the information obtained from the infinitesimal element over a predetermined period of time is below a predetermined threshold, even while the vehicle 1 is moving.

[0038] The vehicle speed limit setting unit 22 outputs a first maximum vehicle speed signal indicating a first maximum vehicle speed V1 in the autonomous driving mode to the vehicle control unit 3 of the vehicle 1 in accordance with the determination result of the abnormality determination unit 21. More specifically, the vehicle speed limit setting unit 22 executes the processing shown in Fig. 5. Fig. 5 is a flowchart of the processing executed by the vehicle speed limit setting unit 22.

[0039] 5, first, the vehicle speed limit setting unit 22 determines whether or not it has acquired an autonomous driving signal from the vehicle control unit 3 (step S01). If the vehicle speed limit setting unit 22 has not acquired an autonomous driving signal (step S01: No), the vehicle speed limit setting unit 22 ends the process.

[0040] If the vehicle speed limit setting unit 22 has acquired an autonomous driving signal (step S01: Yes), it determines whether the index S is equal to or greater than a first predetermined value T1 (step S02). The index S is an index that represents the proportion of the sum Sd of infinitesimal elements whose detection results have been determined to be abnormal by the abnormality determination unit 21 to the total number Smax of all infinitesimal elements that make up a predetermined area, when Sd is the sum of the infinitesimal elements. For example, the index S can be expressed as S = Sd / Smax, or S = Smax / Sd. In the following description, the index S = Sd / Smax.

[0041] For example, assume that the image generated by camera 6 is composed of 10 million pixels. In this case, Smax is 10 million. Also, assume that the sum Sd of the infinitesimal elements whose detection results are determined to be abnormal by abnormality determination unit 21 is 250,000. Also, assume that first predetermined value T1 is set to 0.15. In this case, vehicle speed limit setting unit 22 calculates index S = Sd / Smax = 250,000 / 10 million = 0.25. In this case, vehicle speed limit setting unit 22 determines that index S: 0.25 is equal to or greater than first predetermined value T1: 0.15 (step S02: Yes), and proceeds to step S03. On the other hand, if the index S is less than the first predetermined value T1 (step S02: No), the process ends.

[0042] In step S03, the vehicle speed limit setting unit 22 determines whether the calculated index S is equal to or greater than a second predetermined value T2, which is greater than a first predetermined value T1. Here, it is assumed that the second predetermined value T2 is set to 0.35. If the calculated index S is 0.25, the vehicle speed limit setting unit 22 determines that the index S is not equal to or greater than the second predetermined value T2 (step S03: No), outputs a first maximum vehicle speed signal indicating a first maximum vehicle speed V1 in the autonomous driving mode to the vehicle control unit 3 (step S04), and ends the processing. Here, the first maximum vehicle speed V1 in the autonomous driving mode is the maximum speed of the vehicle 1 that is set when the vehicle 1 travels in the autonomous driving mode. For example, the vehicle speed limit setting unit 22 can output a first maximum vehicle speed signal indicating 20 km / h as the maximum vehicle speed.

[0043] As described above, according to the sensor system 20 of this embodiment, a first maximum vehicle speed signal indicating the first maximum vehicle speed V1 in the autonomous driving mode is output to the vehicle 1 in accordance with the determination result of the abnormality determination unit 21. The vehicle control unit 3 executes the autonomous driving mode based on the output of an external sensor 6, such as a camera. If the detection results of the external sensor 6 become abnormal due to mud or other factors, making the reliability of the external sensor 6 unreliable, the vehicle control unit 3 finds it difficult to execute the autonomous driving mode. However, if the detection results of the external sensor 6 are not completely reliable but still provide reasonable detection results, the vehicle control unit 3 may be able to execute the autonomous driving mode at a speed slower than the normal speed, even if it is difficult to execute the autonomous driving mode at the normal speed. Therefore, in this embodiment, if the abnormality determination unit 21 determines that the detection results of the external sensor 6 are abnormal due to mud or other factors, the vehicle speed limit setting unit 22 outputs a maximum vehicle speed to the vehicle control unit 3, and the vehicle control unit 3 executes the autonomous driving mode at a speed equal to or lower than the first maximum vehicle speed V1. This allows the vehicle 1 to travel a longer distance in the autonomous driving mode.

[0044] In the sensor system 20 according to this embodiment, the external sensor 6 has a transmitter that emits a signal and / or a receiver that receives a signal. When the abnormality determination unit 21 determines that an abnormality has occurred on the surface of the receiver and / or transmitter due to scratches or dirt and the abnormality area is larger than a threshold, the vehicle speed limit setting unit 22 is configured to output a first maximum vehicle speed signal.

[0045] Returning to the flowchart of Figure 5, if it is determined in step S03 that the index S is equal to or greater than the second predetermined value T2 (step S03: Yes), the vehicle speed limit setting unit 22 further determines whether the index S is equal to or greater than a third predetermined value T3 that is greater than the second predetermined value T2 (step S05).

[0046] If it is determined that the index S is equal to or greater than the second predetermined value T2 and less than the third predetermined value T3 (step S05: No), the vehicle speed limit setting unit 22 outputs a second maximum vehicle speed signal indicating a second maximum vehicle speed V2 in the autonomous driving mode to the vehicle control unit 3 (step S06), and ends the processing. Here, the second maximum vehicle speed V2 is a value smaller than the first maximum vehicle speed V1.

[0047] When the index S is equal to or greater than the second predetermined value T2, which is greater than the first predetermined value T1, this indicates that there are more microelements with abnormalities in the detection results than when the index S is equal to or greater than the first predetermined value T1 but less than the second predetermined value T2. This indicates that the camera 6 is heavily soiled. Therefore, in step S06, the vehicle speed limit setting unit 22 outputs a second maximum vehicle speed signal indicating a second maximum vehicle speed V2, which is smaller than the first maximum vehicle speed V1, to the vehicle control unit 3. In this way, when the index S is equal to or greater than the second predetermined value T2 but less than the third predetermined value T3, indicating that the reliability of the external sensor 6 is reduced compared to when the index S is equal to or greater than the first predetermined value T1 but less than the second predetermined value T2, the vehicle control unit 3 executes the autonomous driving mode at a lower speed, thereby preventing any disruption to the execution of the autonomous driving mode. By gradually lowering the maximum vehicle speed in accordance with the increase in the number of microelements with abnormalities in the detection results, an extremely low maximum vehicle speed is not suddenly set when the number of microelements with abnormalities in the detection results exceeds a predetermined value. This improves convenience for users, such as the owner and driver of the vehicle 1.

[0048] If it is determined in step S05 that the index S is equal to or greater than the third predetermined value T3 (step S05: Yes), the vehicle speed limit setting unit 22 cancels the destination currently set in the vehicle control unit 3, sets a predetermined destination, and ends the process. The predetermined destination may be, for example, a vehicle repair shop, a car dealership, the user's home, or the like. The predetermined destination may be set by the provider of the sensor system 20, the provider of the vehicle 1 (car manufacturer), or the vehicle user.

[0049] When the index S is equal to or greater than the third predetermined value T3, which is greater than the first predetermined value T1 and the second predetermined value T2, this indicates that there are a significantly greater number of minute elements causing abnormalities in the detection results than when the index S is less than the third predetermined value T3. In other words, this indicates that the degree of dirt on the camera 6 is quite large. Therefore, in step S07, the vehicle speed limit setting unit 22 moves the vehicle 1 to a predetermined destination to have the external sensor 6 inspected.

[0050] In step S07, the vehicle speed limit setting unit 22 may be configured to output a signal to stop the vehicle in addition to causing the vehicle control unit 3 to set a predetermined destination. If the reliability of the detection results of the external sensor 6 has significantly decreased, the vehicle may be stopped and the external sensor 6 may be inspected on the spot, or an inspection technician may be called.

[0051] In the above-described embodiment, the index S is compared with the first predetermined value T1, and then with the second predetermined value T2 and the third predetermined value T3. However, the vehicle speed limit setting unit 22 may be configured to compare the index S only with the first predetermined value T1. The vehicle speed limit setting unit 22 may be configured to compare the index S with the first predetermined value T1 and the second predetermined value T2. Alternatively, the vehicle speed limit setting unit 22 may be configured to compare the index S with the first predetermined value T1 and the third predetermined value T3. In addition, although the example in which the third predetermined value T3 is greater than the second predetermined value T2 has been described, the third predetermined value T3 may be a value smaller than the second predetermined value T2.

[0052] In addition, the embodiment has been described in which the index is calculated as S = Sd / Smax, and the index S increases as the number of minute elements with abnormalities in the detection results increases. Alternatively, the index may be calculated as S = Smax / Sd. In this case, the first predetermined value T1, the second predetermined value T2, and the third predetermined value T3 described above are smaller in this order.

[0053] Furthermore, the vehicle speed limit setting unit 22 may be configured to execute the processing shown in Fig. 6. Fig. 6 is a flowchart of a method according to a modified example of the present invention, executed by the vehicle speed limit setting unit 22. As shown in Fig. 6, the vehicle speed limit setting unit 22 determines whether or not it has acquired an autonomous driving signal from the vehicle control unit 3 (step S11), and further determines whether or not the index S is equal to or greater than a first predetermined value T1 (step S12). These steps S11 and S12 are similar to steps S01 and S02 described above, and therefore will not be described again.

[0054] If it is determined in step S12 that the index S is equal to or greater than the first predetermined value T1 (step S12: Yes), the vehicle speed limit setting unit 22 outputs the first maximum vehicle speed V1 to the vehicle control unit 3 (step S13), and further outputs an activation signal to the cleaner control unit 25 to activate the cleaner 24 (step S14). The cleaner may be activated only once or multiple times.

[0055] When the vehicle speed limit setting unit 22 receives a signal indicating that the operation of the cleaner 24 has been completed (step S15), it again receives the number of minute elements in the detection results that are abnormal from the abnormality determination unit 21, calculates the index S, and determines whether the index S is greater than or equal to the first predetermined value T1 (step S16).

[0056] If it is determined that the index S has fallen below the first predetermined value T1 after the cleaner 24 has been activated (step S16: No), the vehicle speed limit setting unit 22 outputs a cancellation signal to the vehicle control unit 3 to cancel the setting of the first maximum vehicle speed V1 (step S16). In other words, if the mud and dust adhering to the outer cover 34 has been removed by the activation of the cleaner 24, it is no longer necessary to limit the maximum vehicle speed in the autonomous driving mode, so the cancellation signal is output to the vehicle control unit 3, and the vehicle control unit 3 can execute the autonomous driving mode without limiting the maximum vehicle speed.

[0057] On the other hand, if it is determined that the index S remains equal to or greater than the first predetermined value T1 even after the cleaner 24 has been activated (step S16: Yes), the vehicle speed limit setting unit 22 cancels the destination currently set in the vehicle control unit 3, sets a predetermined destination, and ends the process. In other words, if the number of minute elements showing abnormalities in the detection results does not decrease even after the cleaner 24 has been activated, it is assumed that scratches or cracks have occurred in the outer cover 34 or the inner lens 33. Therefore, in this embodiment, if it is determined that the index S remains equal to or greater than the first predetermined value T1 even after the cleaner 24 has been activated, the vehicle 1 can be moved to a repair shop or the like for inspection.

[0058] In the above-described embodiment, the sensor system 20 has a vehicle speed limit setting unit 22 and an abnormality determination unit 21, and the vehicle speed limit setting unit 22 of the sensor system 20 outputs a maximum vehicle speed signal, etc. to the vehicle control unit 3, but the present invention is not limited to this example.

[0059] Fig. 7 is a system block diagram of a vehicle 1A according to a first modified example of the present invention. As shown in Fig. 7, the vehicle 1A has a vehicle system 2A and a sensor system 20A. The vehicle system 2A has a vehicle control unit 3 and a vehicle speed limit setting unit 22A. The sensor system 20A has an external sensor 6, an abnormality determination unit 21, a cleaner 24, and a cleaner control unit 25. In this case, the abnormality determination unit 21 of the sensor system 20A may be configured to output the number of minute elements having an abnormality in the detection results to the vehicle system 2A, and the vehicle speed limit setting unit 22A of the vehicle system 2A may calculate an index S and compare it with a predetermined value.

[0060] Alternatively, the present invention may be configured as shown in Fig. 8. Fig. 8 is a system block diagram of a vehicle 1B according to a second modified example of the present invention. As shown in Fig. 8, vehicle 1B has a vehicle system 2B and a sensor system 20B. Vehicle system 2B has a vehicle speed limit setting unit 22B and an abnormality determination unit 21B. Sensor system 20B has an external sensor 6, a cleaner 24, and a cleaner control unit 25. In this case, the output of external sensor 6 of sensor system 20B may be output to vehicle system 2B, abnormality determination unit 21 of vehicle system 2B may calculate the number of infinitesimal elements in which an abnormality has occurred in the detection results, and vehicle speed limit setting unit 22B of vehicle system 2B may calculate index S and compare it with a predetermined value.

[0061] As shown in FIG. 7 and FIG. 8, the first maximum vehicle speed in the autonomous driving mode may be set by the vehicle, rather than the sensor system, in accordance with the determination result of the abnormality determination unit. In other words, the present invention can also be expressed as a control method for a vehicle capable of running in autonomous driving mode, using a sensor system 20 including a sensor that acquires information outside the vehicle and an abnormality judgment unit 21 that judges whether an abnormality caused by a scratch or dirt has occurred in the detection result of the sensor, and in which a first maximum vehicle speed in autonomous driving mode is set according to the judgment result of the abnormality judgment unit 21. Alternatively, the present invention can be expressed as a vehicle capable of autonomous driving, having an autonomous driving execution unit that drives the vehicle in autonomous driving mode, a sensor that acquires information outside the vehicle, an abnormality judgment unit 21 that judges whether an abnormality caused by a scratch or dirt has occurred in the detection results of the sensor, and a vehicle speed limit setting unit 22 that generates a first maximum vehicle speed signal that indicates a first maximum vehicle speed in autonomous driving mode according to the judgment result of the abnormality judgment unit 21.

[0062] <Various Modifications> Although the embodiments of the present invention have been described above, it goes without saying that the technical scope of the present invention should not be construed as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents.

[0063] In the present embodiment, the vehicle driving modes are described as including the fully automated driving mode, the advanced driving assistance mode, the driving assistance mode, and the manual driving mode. However, the vehicle driving modes should not be limited to these four modes. The vehicle driving modes may include at least one of these four modes. For example, the vehicle driving modes may be executable in only one of the four modes.

[0064] Furthermore, the classification and display format of the vehicle's driving modes may be changed as appropriate in accordance with the laws, regulations, or rules related to autonomous driving in each country. Similarly, the definitions of "fully autonomous driving mode," "advanced driving assistance mode," and "driving assistance mode" described in the description of this embodiment are merely examples, and these definitions may be changed as appropriate in accordance with the laws, regulations, or rules related to autonomous driving in each country.

[0065] Although the embodiments of the present invention have been described above, it goes without saying that the technical scope of the present invention should not be construed as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents.

[0066] This application is based on a Japanese patent application (Patent Application No. 2021-008956) filed on January 22, 2021, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0067] According to the present invention, a sensor system, a vehicle control method, and a vehicle are provided that can ensure a long distance traveled in autonomous driving mode. [Explanation of symbols]

[0068] Vehicles 1, 1A, 1B 2, 2A, 2B vehicle system 3 Vehicle control unit 5 Internal Sensor 6 External sensors (cameras) 7 Lamp 10. Wireless Communication Unit 11 Map information storage unit 12 Steering actuator 13 Steering device 14 Brake actuator 15 Brake equipment 16 Accelerator actuator 17 Accelerator 20, 20A, 20B Sensor System 21,21B Abnormality judgment section 22, 22A, 22B Vehicle speed limit setting section 23 Operation mode acquisition unit 24 Cleaner 25 Cleaner control unit 31 Image sensor 32 PCB 33 Inner Lens 34 Outer cover 35 Housing 40 images 41 pixels

Claims

1. A sensor system mounted on a vehicle capable of running in an autonomous driving mode. a sensor for acquiring information about the outside of the vehicle; an abnormality determination unit that determines whether an abnormality caused by a scratch or dirt has occurred based on the detection result of the sensor; a vehicle speed limit setting unit that outputs a first maximum vehicle speed signal indicating a first maximum vehicle speed in the autonomous driving mode to the vehicle in accordance with a determination result of the abnormality determination unit, The sensor divides a predetermined area outside the vehicle into arbitrary infinitesimal elements, and acquires information about the predetermined area by collecting information about each of the infinitesimal elements; the abnormality determination unit is capable of determining whether or not an abnormality has occurred in the detection result for each of the infinitesimal elements, the vehicle speed limit setting unit outputs the first maximum vehicle speed signal when an index S representing a ratio of the sum Sd of the infinitesimal elements determined by the abnormality determination unit to be abnormal in the detection result to a total number Smax of all infinitesimal elements forming the predetermined region becomes equal to or greater than a first predetermined value T1; the vehicle speed limit setting unit outputs a second maximum vehicle speed signal indicating a second maximum vehicle speed lower than the first maximum vehicle speed to the vehicle when the index S becomes equal to or greater than a second predetermined value T2 which is greater than the first predetermined value T1; Sensor system.

2. The sensor has a transmitter that emits a signal and / or a receiver that receives a signal, 2. The sensor system of claim 1, wherein the vehicle speed limit setting unit outputs the first maximum vehicle speed signal when the abnormality area determined by the abnormality determination unit to be an abnormality caused by scratches or dirt on the surface of the receiving unit and / or the transmitting unit is greater than a threshold value.

3. a driving mode acquisition unit that acquires an autonomous driving signal indicating that the vehicle is driving in an autonomous driving mode; The sensor system of claim 1, wherein the vehicle speed limit setting unit outputs the first maximum vehicle speed signal when the driving mode acquisition unit acquires the autonomous driving signal and the index S becomes equal to or greater than the first predetermined value T1.

4. The sensor system of claim 1, wherein the vehicle speed limit setting unit causes a user to set a location or an automobile repair shop that has been preset by the user when the index S becomes equal to or greater than a third predetermined value T3 that is greater than the first predetermined value T1.

5. a cleaner capable of cleaning the sensor; a cleaner control unit that controls the cleaner, the cleaner control unit operates the cleaner when the index S becomes equal to or greater than the first predetermined value T1; 2. The sensor system according to claim 1, wherein the vehicle speed limit setting unit outputs a cancellation signal to cancel the setting of the first maximum vehicle speed when the indicator S becomes less than the first predetermined value T1 after the cleaner is operated.

6. 6. The sensor system of claim 5, wherein the vehicle speed limit setting unit outputs to the vehicle a second maximum vehicle speed signal indicating a second maximum vehicle speed lower than the first maximum vehicle speed, or a stop signal to stop the vehicle, if the indicator S does not become the first predetermined value T1 after the cleaner is operated.

7. The sensor system of claim 5, wherein the vehicle speed limit setting unit sets a location or an automobile repair shop previously set by a user as the destination of the vehicle if the index S does not become equal to or less than the first predetermined value T1 after the cleaner is operated.

8. a cleaner capable of cleaning the sensor; a cleaner control unit that controls the cleaner, the cleaner control unit operates the cleaner when the index S becomes equal to or greater than the first predetermined value T1; 2. The sensor system of claim 1, wherein the vehicle speed limit setting unit outputs to the vehicle a second maximum vehicle speed signal indicating a second maximum vehicle speed lower than the first maximum vehicle speed, or a stop signal to stop the vehicle, if the indicator S does not become less than the first predetermined value T1 after the cleaner is operated.

9. a cleaner capable of cleaning the sensor; a cleaner control unit that controls the cleaner, the cleaner control unit operates the cleaner when the index S becomes equal to or greater than the first predetermined value T1; The sensor system of claim 1, wherein the vehicle speed limit setting unit sets a location or an automobile repair shop previously set by a user as the destination of the vehicle if the indicator S does not become less than the first predetermined value T1 after the cleaner is operated.

10. A method for controlling a vehicle capable of running in an autonomous driving mode using a sensor system including a sensor that acquires information about the outside of the vehicle and an abnormality determination unit that determines whether an abnormality due to a scratch or dirt has occurred in a detection result of the sensor, A first maximum vehicle speed in the autonomous driving mode is set according to a determination result of the abnormality determination unit, a predetermined area outside the vehicle is divided into arbitrary infinitesimal elements, and information on each of the infinitesimal elements is collected by the sensor to obtain information on the predetermined area; The abnormality determination unit determines whether or not an abnormality occurs in the detection result for each of the infinitesimal elements, When a sum of the infinitesimal elements determined by the abnormality determination unit to have an abnormality in the detection result is Sd, and an index S representing the proportion of the sum Sd to a total number Smax of all infinitesimal elements forming the predetermined region becomes equal to or greater than a first predetermined value T1, a first maximum vehicle speed signal indicating the first maximum vehicle speed is output by the vehicle speed limit setting unit, When the indicator S becomes equal to or greater than a second predetermined value T2 that is greater than the first predetermined value T1, the vehicle speed limit setting unit outputs a second maximum vehicle speed signal that indicates a second maximum vehicle speed that is smaller than the first maximum vehicle speed to the vehicle. How to control the vehicle.

11. An autonomously driven vehicle, an autonomous driving execution unit that drives the vehicle in an autonomous driving mode; a sensor for acquiring information about the outside of the vehicle; an abnormality determination unit that determines whether an abnormality caused by a scratch or dirt has occurred in the detection result of the sensor; a vehicle speed limit setting unit that generates a first maximum vehicle speed signal indicating a first maximum vehicle speed in an autonomous driving mode in accordance with a determination result of the abnormality determination unit, The sensor divides a predetermined area outside the vehicle into arbitrary infinitesimal elements, and acquires information about the predetermined area by collecting information about each of the infinitesimal elements; the abnormality determination unit is capable of determining whether or not an abnormality has occurred in the detection result for each of the infinitesimal elements, the vehicle speed limit setting unit outputs the first maximum vehicle speed signal when an index S representing a ratio of the sum Sd of the infinitesimal elements determined by the abnormality determination unit to be abnormal in the detection result to a total number Smax of all infinitesimal elements forming the predetermined region becomes equal to or greater than a first predetermined value T1; the vehicle speed limit setting unit outputs a second maximum vehicle speed signal indicating a second maximum vehicle speed lower than the first maximum vehicle speed to the vehicle when the index S becomes equal to or greater than a second predetermined value T2 which is greater than the first predetermined value T1; vehicle.

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