WO2019029804A1

WO2019029804A1 - Vehicle camera system comprising an integrated lens cleaning mechanism, vehicle and method for automatically cleaning a camera lens of a vehicle camera system

Info

Publication number: WO2019029804A1
Application number: PCT/EP2017/070227
Authority: WO
Inventors: Nicolas Berne
Original assignee: Volvo Lastvagnar Ab
Priority date: 2017-08-09
Filing date: 2017-08-09
Publication date: 2019-02-14

Abstract

The invention concerns a vehicle camera system (2), comprising a camera (6) comprising a camera lens (60), a camera housing (4) receiving the camera (6), and an integrated lens cleaning mechanism, including a hinged element (8) on the camera housing (4), comprising at least one, preferably several fluid spray nozzles (80) for spraying a cleaning fluid on the camera lens (60), and a holding means for holding the hinged element in a predetermined position.

Description

Vehicle camera system comprising an integrated lens cleaning mechanism, vehicle and method for automatically cleaning a camera lens of a vehicle camera system The present invention concerns a vehicle camera system.

In the automotive advanced camera solutions provide safety systems such as forward collision warning, following distance indication and lane departure warning. These functions are realized with a forward-looking camera mounted for example below the front windshield of the vehicle.

Also, side cameras may be used in the blind spot information systems or in replacement of the outside mirrors and more and more vehicles include a back-up assist system with a rearview camera. In addition, autonomous vehicles include many cameras.

Given the importance of such functions, the cameras must be kept free of soiling in order to provide reliable information.

To this end, the cameras should be cleaned regularly, especially the forward-looking camera. The cameras may be cleaned manually by the driver using a dry or damp cloth. However, there is a risk that the driver forgets to clean the camera. Also, the camera lens can be difficult to reach. For example, some of the vehicle cameras are very high relative to the ground and are not accessible without special equipment (step ladder).

Therefore, there exist automatic systems for cleaning the camera lens on a regular basis. Typically, JP 2016 008 005 discloses a camera lens cleaning system for a rearview camera. This system includes a fixedly attached air nozzle for injecting compressed air towards the camera lens. A specificity of this system is that compressed air is produced by the rotation of a rear wiper device which is driven by an electric motor. One drawback of using a fixed nozzle is that it renders impossible to clean the full surface of the lens.

It is also known to equip the vehicle with telescopic nozzles, that are basically the same than that used for cleaning the vehicle headlights, but much smaller. However, these systems do not provide satisfaction, in particular in terms of cleaning performance.

The aim of the present invention is to propose a new vehicle camera system that remedies the abovementioned drawbacks.

To this end, the invention concerns a vehicle camera system according to claim 1 . Thanks to the invention, during the cleaning process, the nozzle(s) rotate(s) around the surface of the camera lens. This enables optimizing the cleaning performances as the whole surface of the camera lens can be cleaned.

Further advantageous features of the vehicle camera system are defined in claims 2 to 7. The invention also concerns a vehicle according to claim 8. Advantageous features of the vehicle are specified in claims 9 and 10.

The invention also concerns a method according to claim 1 1 . Preferably, the method includes the features of claim 12.

The invention will be better understood from reading the following description, given solely by way of two non-limiting examples and with reference to the appended drawings, which are schematic depictions, in which:

- figure 1 is a front view of vehicle, in particular a heavy-duty vehicle, comprising a camera system according to the invention;

- figure 2 is a perspective view of the camera system of figure 1 , represented alone,

- figure 3 is a perspective view analog to that of figure 2, wherein the camera system is in a cleaning configuration,

- figure 4 is a scheme of a first embodiment of the camera system according to the invention; and

- figure 5 is a scheme of a second embodiment of the camera system according to the invention.

Figure 1 represents a vehicle 1 which is, in the example, a heavy-duty vehicle, in particular a truck. However, the invention is applicable to light-duty vehicles and to any other heavy-duty vehicles, such as buses or construction vehicles.

The vehicle 1 includes a camera system 2. The camera system 2 is preferably mounted independently on the vehicle 1 , meaning that the camera system 2 may be considered as a spare part.

As shown on figure 2, the camera system 2 includes a camera 6 comprising a camera lens 60, a camera housing 4 receiving the camera 6 and an integrated lens cleaning mechanism.

In the example, the camera 6 is a forward-looking camera that is mounted below the front windshield of the vehicle 1 . However, any other emplacement may be suitable. Typically, the camera 6 may be part of a safety system, such as a forward collision warning system, a following distance indication system and/or a lane departure warning system. Alternatively, the camera 6 may be a rearview camera or a side camera replacing an outside mirror.

As shown on figure 2, the integrated lens cleaning mechanism includes a hinged element 8 on the camera housing 4, comprising at least one, preferably several fluid spray nozzles 80. These fluid spray nozzles 80 include nozzles 80.1 , particularly visible on figure 4 or 5, for spraying a cleaning fluid on the camera lens 60, and a holding means for holding the hinged element 8 in a predetermined position (represented on figure 2). Typically, the predetermined position is the position of the hinged element 8 outside cleaning sequences, i.e. the position of the hinged element 8 when the vehicle 1 is moving for instance. In the predetermined position, the hinged element 8 is preferably in abutment against the camera housing 4.

The cleaning fluid may be water or any other fluid. The vehicle 1 includes a cleaning fluid supply 14, such as a tank, for supplying the fluid spray nozzle(s) 80.1 with cleaning fluid. A pump (not represented) is used for pumping the cleaning fluid from the cleaning fluid supply 14 to the hinged element 8. The pump is optional in the configuration where the cleaning fluid supply 14 is arranged above the vehicle camera 6. Indeed, in this last example, the cleaning fluid may flow from the cleaning fluid supply 14 to the hinged element under gravity only. The flow of cleaning fluid between the cleaning fluid supply 14 and the hinged element 8 may be controlled by a valve (not represented).

Advantageously, the nozzles 80 also comprise at least one, preferably several air nozzles 80.2, particularly visible on figure 4 or 5, for blowing compressed air on the camera lens 60. Accordingly, the vehicle 1 includes a compressed air supply 12 for supplying compressed air to the air nozzle(s) 80.2. Blowing compressed air following water spraying enables removing and/or drying liquid droplets that may remain on the camera lens surface after the spraying, in order to avoid deteriorating the reliability of the provided information.

Typically, the hinged element 8 defines a cleaning fluid channel 15 and a separate compressed air channel 13.

In the example, the air nozzles 80.2 and/or the fluid spray nozzles 80.1 are evenly distributed.

Preferably, the hinged element 8 is in the form of an arch, i.e. of semi-circular shape. The holding means is represented on figures 4 and 5 only. In the embodiment of figure 4, the holding means is an electric motor 10 that is used for pivoting the hinged element 8 from the predetermined position to an end of travel position, represented on figure 3. In the example, the angular stroke between the predetermined position and the end of travel position is about 100°. However, the angular stroke may be different from 100°, for example equal to 180°. In the alternative embodiment of figure 5, the holding means a torsion spring 1 1 that is able to return the hinged element 8 to the predetermined position, following cleaning fluid spraying.

As shown on figure 2, the camera lens 60 has an optical axis X60, which is defined as a line along which light may propagate through the camera lens without being deviated. The optical axis X60 intersects with a center of curvature of the lens 60. Advantageously, a rotation axis Y8 of the hinged element 8 is perpendicularly intersecting the optical axis X60 of the camera lens 60. Accordingly, the angle between the cleaning fluid jets (and the air jet(s) if any) and the camera lens surface remains unchanged during the cleaning process. In particular, the cleaning fluid jets (and the air jet(s) if any) remain perpendicular to the camera lens surface. This ensures that the whole surface of the camera lens 60 is uniformly and efficiently cleaned. Such advantage cannot be obtained with prior art cleaning systems, such as telescopic nozzles.

Typically, the cleaning sequences can be performed when the vehicle 1 is parked. During a cleaning sequence, cleaning fluid is sprayed, through the nozzles 80.1 , onto the camera lens 60 while the hinged element 8 is moved between the predetermined position and the end of travel position.

Preferably, compressed air is blown, through the nozzles 80.2, onto the camera lens 60 while the hinged element 8 is moved back to the predetermined position, i.e. from the end of travel position to the predetermined position.

In the embodiment of figure 4, the electric motor 10 drives the hinged element 8 in rotation between the predetermined position and the end of travel position, and reciprocally.

However, in the particular example of figure 5, the hinged element 8 automatically moves, under gravity, from the predetermined position to the end of travel position when the cleaning fluid and/or the compressed air is injected inside the channel(s) 13 and/or 15 of the hinged element 8.

This means that the displacement of the hinged element 8 between the predetermined position and the end of travel position may be pneumatically and/or hydraulically controlled.

More precisely, the injection of cleaning fluid inside the hinged element channel(s) 13 and/or 15 adds weight to the hinged element 8, in a way that the gravity force applying on the hinged element 8 produces a lever effect that causes the hinged element 8 to pivot (See arrow F1 on figure 2) from the predetermined position to the end of travel position. In particular, the momentum resulting from lever effect overcomes the momentum of the torsion spring 1 1 . During the travel of the hinged element 8 between the predetermined position and the end of travel position, the torsion spring compresses and stores mechanical energy.

When the hinged element 8 reaches the end of travel position, cleaning fluid spraying is stopped and leaves room for compressed air blowing, making the hinged element 8 lighter. Accordingly, the hinged element 8 moves back into the predetermined position under the action of the torsion spring 1 1 , i.e. under the effect of the momentum applied by the torsion spring (See arrow F2 on figure 3). In particular, the torsion spring 1 1 restitutes the mechanical energy stored during the travel of the hinged element 8 between the predetermined position and the end of travel position.

In a non-represented alternative embodiment, the vehicle 2 is an autonomous vehicle.

In another non-represented alternative embodiment, the hinged element 8 is of semi-rectangular shape or of any other suitable shape.

The features of the two described embodiments and of non-represented alternative embodiments may be combined together in order to generate new embodiments of the invention.

Claims

1 . Vehicle camera system (2), comprising :

- a camera (6) comprising a camera lens (60),

- a camera housing (4) receiving the camera (6), and

- an integrated lens cleaning mechanism,

characterized in that the integrated lens cleaning mechanism includes:

- a hinged element (8) on the camera housing (4), comprising at least one, preferably several fluid spray nozzles (80.1 ) for spraying a cleaning fluid on the camera lens (60), and

a holding means (10, 1 1 ) for holding the hinged element in a predetermined position (figure 2).

2. Vehicle camera system according to claim 1 , characterized in that the hinged element (8) comprises at least one, preferably several air nozzles (80.2) for blowing compressed air on the camera lens (60).

3. Vehicle camera system according to claim 1 or 2, characterized in that the air nozzles (80.2) and/or the fluid spray nozzles (80.1 ) are evenly distributed.

4. Vehicle camera system according to any previous claim, characterized in that a rotation axis (Y8) of the hinged element (8) is perpendicularly intersecting an optical axis (X60) of the camera lens (60).

5. Vehicle camera system according to any previous claim, characterized in that the hinged element (8) is in the form of an arch.

6. Vehicle camera system according to any previous claim, characterized in that the holding means is an electric motor (10) or a torsion spring (1 1 ).

7. Vehicle camera system according to previous claim, characterized in that the holding means (10, 1 1 ) is able to return the hinged element (8) to the predetermined position, following cleaning fluid spraying.

8. Vehicle (1 ), comprising a camera system (2) according to any previous claim and a cleaning fluid supply (14) for supplying the fluid spray nozzle(s) (80.1 ) with cleaning fluid.

9. Vehicle according to previous claim, characterized in that the camera system is according to claim 2 and in that the vehicle includes a compressed air supply for supplying compressed air to the air nozzle(s).

10. Vehicle according to claim 8 or 9, characterized in that the vehicle is a heavy- duty vehicle, such as a truck.

1 1 . Method for automatically cleaning a camera lens (60) of a vehicle camera system (2) according to any one of the claims 1 to 7, the method including steps consisting in:

a) moving the hinged element (8) between the predetermined position and an end of travel position,

b) spraying the cleaning fluid while the hinged element (8) is moved between the predetermined position and the end of travel position.

12. Method according to previous claim, characterized in that the method further includes steps consisting in:

c) moving the hinged element (8) back to the predetermined position, and d) blowing compressed air while the hinged element (8) is moved between the end of travel position and the predetermined position.