Road surface condition detection device and road surface condition notification device

Abstract

To solve the problem that, even though an attempt to roughly grasp the condition of a road surface in contact with tires of a vehicle by detecting the condition of a road surface on the sides of the vehicle is useful as it may be slippery when getting off the vehicle if the road surface on the sides of the vehicle is wet or frozen and requires caution, attempting to detect the road condition by irradiating the sides of the vehicle with light may be bothersome to a driver and people around the vehicle.SOLUTION: The road surface condition is detected by projecting an image of visible light onto a road surface below the side of a vehicle and receiving reflected light of the projected image.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a road surface condition detection device that detects the road surface condition on the side of a vehicle, and a road surface condition notification device that notifies the road surface condition on the side of the vehicle.

Background Art

[0002] Road surface conditions such as wetness, freezing, and unevenness of the road surface affect the running of vehicles. Patent Document 1 describes a system that irradiates the road surface in front of the vehicle with measurement light that forms an orientation pattern for detecting the road surface condition separately from the illumination light, and detects the road surface condition based on the measurement light received by the imaging device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The system of Patent Document 1 detects the road surface condition in front of the vehicle, but does not detect the road surface condition on the side of the vehicle. However, if the road surface on the side of the vehicle is wet or frozen, it is likely to be slippery when a person gets out of the vehicle, and caution may be required. Also, if the road surface condition on the side of the vehicle is detected, the road surface condition in contact with the tires of the vehicle can also be roughly grasped. Therefore, it is conceivable to irradiate light on the side of the vehicle and detect the road surface condition with a light receiving element such as an imaging device. However, irradiating light on the side of the vehicle may give a sense of discomfort to the driver and people around the vehicle. This sense of discomfort can be given whether the vehicle is running or stopped.

Means for Solving the Problems

[0005] The road surface detection device according to an embodiment of the present invention includes a light emitting device that projects an image onto the road surface at the lower side of the vehicle by visible light, an optical sensor provided on the side of the vehicle, and an ECU. The optical sensor receives the reflected light of the projected image and transmits it to the ECU. The ECU determines the road surface condition. When the vehicle is running, the visible light is switched to invisible light, the reflected light of the invisible light projected onto the road surface is received, and the ECU determines the road surface condition according to the light reception amount of the optical sensor.

Effects of the Invention

[0006] By receiving the projected visible light mark and detecting the road surface condition, it is possible to detect the road surface condition by projection that is less likely to give a sense of discomfort to the driver or people around the vehicle even when projected to the side of the vehicle. Also, by projecting the mark, it is possible to obtain a sense of luxury or the like along with the detection of the road surface condition.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

Examples

[0008] As shown in FIG. 1 when viewed from below, the vehicle 1 in Example 1 is provided with a small projector 21, a camera 22 which is an optical sensor, and an infrared LED 23 below the left and right door mirrors 2. As shown in FIG. 2, the left and right projectors 21, cameras 22, and infrared LEDs 23 are connected to the ECU 4. Also, the door knob sensor 5, speaker 6, and other ECU 7 of the front door are also connected to the ECU 4.

[0009] When the vehicle 1 stops and the door knob sensor 5 inside the vehicle is touched, an image 8 of a foot pattern is projected onto the road surface at the lower side of the vehicle 1 in visible light from the projector 21 on the touched side under the control of the ECU 4. Thereby, it is possible to convey to people outside that the occupant is getting out of the vehicle, and it does not give a sense of discomfort to people outside. FIG. 3 shows a situation where the driver in the right front seat touches the door knob to get out of the vehicle. When the occupant in the left front seat touches the door knob, the left projector 21 operates and projects the image 8 below the left door mirror 2.

[0010] The reflected light of the projected image 8 is received by the camera 22 and photographed. Then, the photographed video is sent to the ECU 4, and the road surface condition is determined. Thereby, it functions as a road surface condition detection device. When the ECU 4 determines that the road surface is wet, an audio signal is transmitted from the ECU 4 to the speaker 6, and an announcement saying "The road surface is wet. Please be careful not to slip." is played inside the vehicle. When it is determined that there is a puddle, an announcement saying "There is a puddle. Please be careful." is played inside the vehicle. Also, when it is determined that the road surface is frozen, an audio announcement saying "The road surface is frozen. Please be careful as it is slippery." is made. Thereby, it functions as a road surface condition notification device that prompts the passengers to be careful when getting out of the vehicle.

[0011] In this embodiment, infrared rays, which are invisible light, are irradiated during driving. When irradiating infrared rays, which are invisible light, there is no need to use an image. The ECU 4 is connected to another ECU 7. When a driving signal indicating that the vehicle 1 is in motion is sent from the other ECU 7, the ECU 4 stops the emission of visible light by the projector 21. Then, infrared rays are irradiated from the two infrared LEDs 23 onto the road surface below the door mirror 2. The reflected light of the irradiated infrared rays is received by the camera 22, photographed, and sent to the ECU 4. The ECU 4 determines the road surface condition from the video. Then, the determination result that the road surface is wet and the determination result that it is frozen are transmitted from the ECU 4 to the other ECU 7. Since the road surface where the tire contacts and the road surface below the door mirror 2 are close, the other ECU 7 can estimate the road surface condition where the tire contacts from the transmitted road surface condition. Thereby, it functions as a road surface condition notification device that prompts the driver to be careful of slipping. Also, the control of the four-wheel drive can be changed according to the estimated road surface condition.

[0012] Also, when it is determined that there is a step such as a curb near the lower part of the door mirror 2 while the vehicle 1 is moving forward, if the steering wheel is turned in the direction of the step, a warning is issued from the speaker 6. This can prevent the rear wheels from riding up onto the curb or the like. Also, when the vehicle 1 is moving backward and the steering wheel is turned, when a step is detected, the voice generated from the speaker 6 changes according to the proximity of the step. This can prevent the front wheels from rubbing against the curb when moving backward and aligning the vehicle width during parking.

Embodiment

[0013] In Embodiment 2, the projector 21 and the camera 22 are provided inside the door 9. As shown in FIG. 4, the projector 21 and the camera 22 are attached diagonally downward at the lower rear part inside the front seat door 9. Embodiment 2 has the system configuration shown in FIG. 2, similar to Embodiment 1.

[0014] In Embodiment 2, when the door 9 is opened, an image 8 is projected in visible light from the projector 21 of the opened door 9 onto the road surface at the lower side of the vehicle 1 under the control of the ECU 4. The projected image 8 has the functions of footwell lighting and display design. The reflected light of the projected image 8 is received and photographed by the camera 22. Then, the photographed video is sent to the ECU 4 to determine the road surface condition, and an announcement of the road surface condition is made in the same manner as in Embodiment 1. Note that in Embodiment 2, infrared irradiation or the like is not performed during the running of the vehicle 1.

[0015] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. Also, the above-described embodiments can be combined by diverting each other's technologies as long as there are no particular contradictions or problems in their purposes and configurations.

[0016] For example, in Embodiment 1, even during slow travel, the detection is switched to infrared rays which are invisible light while the vehicle is in motion. However, visible light may be projected during slow travel. Further, in the embodiment, the light emitting device and the camera are provided at the lower part of the door mirror or the lower inner part of the door, but they can be appropriately provided on the side of the vehicle.

[0017] The image may be a pattern or character indicating getting off the vehicle, etc., or may be a mark indicating the brand of the vehicle 1. Further, other design patterns or images may also be used. Further, instead of the camera, other optical sensors may be used to determine the road surface condition based on the amount of received light, etc.

Explanation of Signs

[0018] 1 Vehicle 2 Door mirror 21 Projector (light emitting device) 22 Camera (optical sensor) 23 Infrared LED (light emitting device) 3 Tire 4 ECU 5 Door knob sensor 6 Speaker 7 Other ECU 8 Image 9 Door

Claims

1. A light-emitting device that projects an image onto the road surface at the lower side of the vehicle by visible light, an optical sensor provided on the side of the vehicle, and an ECU are provided. The optical sensor receives the reflected light of the projected image and transmits it to the ECU. The ECU determines the road surface condition. While the vehicle is running, the visible light is switched to invisible light, and the reflected light of the invisible light projected onto the road surface is received. A road surface condition detection device in which the ECU determines the road surface condition according to the amount of light received by the optical sensor.

2. The road surface condition detection device according to claim 1, wherein the optical sensor is a camera provided on the side of the vehicle.

3. A road surface condition notification device comprising the road surface condition detection device according to claim 1 or 2, projecting the visible light when the vehicle stops, and prompting the occupant to pay attention when getting off the vehicle if the reflected light of the received visible light indicates wetness of the road surface condition.

4. A road surface condition notification device comprising the road surface condition detection device according to claim 1 or 2, and prompting the driver to pay attention to slipping if the reflected light of the invisible light received during the running of the vehicle indicates wetness of the road surface condition.

Images