Patent Application
20170210304
The invention refers to an integrated on board vehicle vision and cleaning system comprising an image sensor unit, a cleaning fluid source, a cleaning fluid circuit, a cleaning fluid pump and at least one cleaning fluid nozzle.
Modern vehicles, and particularly automobiles, mostly so-called SUV's are provided with external view cameras to enhance the driver's vision and to improve safety. Moreover, these cars are often equipped with sensors, which detect approaching and passing cars from behind, which are not visible to the driver in the rear mirrors due to the blind angle, and are not covered by the rear view mirrors.
In the prior art, rear view cameras are often integrated into the rear bumper, the hatch or luggage compartment door of the vehicle nearby the license plate. Due to that position at the car body, camera lenses or protective lens covers, or generally speaking, the sensor coverage are exposed to the vehicle's surroundings and dirt and debris, mud, salt spray etc. accumulate on the lens, or a lens cover or a sensor cover during operation of the vehicle. Particularly, if cameras and/or sensors are integrated in the rear bumper or in the hatch of the vehicle, they are particularly exposed to dirt and mud spray.
Therefore, it is generally known to provide external washing systems for cleaning lenses and sensors.
For example, WO 2012/138455 A1 discloses an external lens washing system for a rear view camera.
Prior art related to such lens washing systems may for example also be taken from WO 01/68425 A1, WO 02/072274 A1, and DE 10 2010 022 163 A1.
Various cleaning concepts have been proposed in the art, either in order to prevent build-up of dirt and debris on the camera lens or to achieve an enhanced cleaning result. As also droplets from residual cleaning fluid on the camera lens deteriorates the external view, for example WO 02/072274A1 proposes fluid and air nozzle assemblies, which are capable of propelling streams of a cleaning fluid and an air mixture onto a vehicle vision device, visible indicator or sensor in order to address this issue. These nozzle assemblies are mounted on a vehicle adjacent to the vehicle vision device and are positioned such that liquid from one type of nozzle and air jets from another type of nozzle intersect prior to impinging upon the vehicle vision device in order to form a spray mixture that cleans the exposed surface of the vehicle's vision device.
Generally, in the prior art it has not been considered that also build-up of dirt and debris, mud, salt spray etc. on the nozzles might be an issue, since the nozzles might get clogged. Another issue with such arrangement of nozzles is that in order to achieve a proper cleaning effect, the nozzles have to be arranged pretty close to the lens cover or to the lens dome. This is not only because of the cleaning effect, but also due to the desire to provide integrated systems, i.e. the camera system and the cleaning system in one assembly.
Yet another issue with such systems is that the external viewing angle should be as wide as even possible. Such wide angle rear view system advantageously also covers at least a part of the rear bumper such that a parking distance indication may be easily provided to the driver. The demand for such wide angle lens systems and for nozzles being placed very close to the lens or lens cover is to some extend conflicting as with rear view cameras it might happen that the nozzles are also covered by the viewing angle of the sensor unit. If a visible image is displayed on a screen within the passenger compartment, the nozzles might be optically distracting.
It is thus an object of the present invention to provide an integrated on board vehicle vision and cleaning system, which overcomes the above-referred draw-backs.
These and other objects are achieved by an integrated on board vehicle vision and cleaning system according to claim 1.
Advantageous embodiments and variations of the inventive concept may be taken from the dependent claims.
In accordance with the present invention an integrated on board vehicle vision and cleaning system is provided, the system comprising:
In other words, the invention aims to maintain a clear vision of the sensor unit by moving the sensor unit below the vehicle's external surface, then cleaning it with fluid by the use of at least one nozzle, thereby removing any built-up of dirt/debris obstructing the user's view, and then moving the sensor unit back in an elevated position above the vehicle's external surface.
The system has also been designed to clear any build up of frost on the camera during cold conditions.
If the sensor unit includes a dome-shaped lens cover, the peripheral rim of the image sensor housing may flush with a vehicle's external surface in the first position, while the dome projects above the vehicle's external surface.
According to that concept of the invention, the nozzle or several nozzles are generally arranged in a concealed fashion, so that the nozzle or the nozzles are not exposed in the first position of the image sensor housing.
A sensor unit in the sense of the present application may be for example an external view camera or just a sensor for detecting approaching and passing cars or even for creating a lane departure warning signal.
A sensor unit in the sense of the present application also may be designed as an external view camera as well as a sensor at the same time to generate a lane departure warning to the driver or to detect objects approaching the vehicle, which are normally not visible in the rear view mirrors.
A sensor unit according to the present invention may be an imaging device using solid state technologies, for instance CMOS or CCD Pixel Sensor Technology in combination with for instance a video monitor display for automotive navigation systems. The image sensor unit may comprise a camera lens system with at least one lens surface or cover surface.
A fluid nozzle within the sense of the present application may be a fluidic oscillator, a pencil jet nozzle or the like. The fluid nozzle may have an adjustable eyeball nozzle body.
A fluid nozzle in the sense of the present application may also be an air nozzle, which may also be any type of nozzle through which an air jet, preferably a pencil jet may be ejected.
A cleaning fluid in the sense of the instant application may be a liquid as well as gas or air. A cleaning fluid pump according to the invention may be a conventional type fluid pump, particularly a conventional type impeller pump with one or several impeller wheels. The fluid pump may have one or more fluid exit ports and at least one fluid entry port receiving a liquid cleaning fluid from a cleaning fluid source. In the event air or gas is to be propelled onto the sensor unit, the cleaning fluid pump may be designed as a piston pump.
In the event the cleaning fluid pump is designed as a conventional type impeller pump for a liquid cleaning fluid, the cleaning fluid pump may be either designed as a dual pump with a switchable sense of rotation or a mono pump with only one sense of rotation.
Particularly, a cleaning fluid pump with a switchable sense of rotation may deliver liquid cleaning fluid to different nozzle systems in dependence of the sense of rotation actually chosen.
A cleaning fluid circuit in the sense of the current application may include a cleaning fluid conduit or cleaning fluid hoses as well as connectors, and valves, i.e. check valves and/or pressure-retaining valves.
A cleaning fluid circuit in the sense of the present application does not necessarily have to be a closed circuit. A person skilled in the art will appreciate that the term “cleaning fluid circuit” includes also only a single cleaning fluid conduit from the cleaning fluid pump to a fluid nozzle. A cleaning fluid circuit must not necessarily be and normally is not a closed loop.
The image sensor housing generally may be moved from the first position into the second position by an electric actuator. This actuator may be designed as a so-called gear motor or as a solenoid actuator.
In one advantageous embodiment according to the invention, the image sensor housing is hydraulically retracted below the vehicle's external surface from the first position into said second position. It is particularly advantageous if such movement from the first position into the second position is achieved by the hydraulic force of the cleaning fluid.
In one aspect of the invention, the image sensor housing and the casing engage each other such that they define a sealed fluid chamber, and in that the fluid chamber communicates with the cleaning fluid circuit, so that the cleaning fluid may be provided under pressure to the fluid chamber.
For example, the bottom of the fluid chamber may be formed by a part of the image sensor housing so that the cleaning fluid pressure forces the image sensor housing into the second retracted position.
One advantageous embodiment of the vehicle vision and cleaning system according to the current application is characterized in that the image sensor housing is biased in the first position by the biasing force of a spring element, and in that the image sensor housing is being forced into the second position by the pressure of the cleaning fluid entering the cleaning fluid chamber.
Preferably, the cleaning fluid chamber and said nozzle are hydraulically connected in parallel to the cleaning fluid pump.
The fluid pressure delivered by the cleaning fluid pump may be in the order of 2 to 5 bar, more preferably about 3 bar depending on the pressure consumption of the nozzle, or an arrangement of several nozzles.
In order to achieve a sequential operation of the hydraulically actuated motion of the image sensor housing and the propulsion of cleaning fluid to the fluid nozzle, the system may comprise one or more pressure retaining valves. For example if one nozzle is provided, the system comprises a pressure retaining valve upstream said nozzle, so that cleaning fluid is only delivered to the nozzle if the pressure built-up in the cleaning fluid chamber raises above a give value, which should be the case if the image sensor housing reaches its second position.
Preferably, the moving pressure in the cleaning fluid chamber, the pressure within the fluid chamber effecting a movement of the image sensor housing, is lower than the moving pressure of a valve body in said pressure retaining valve. Alternatively, the system may be designed such that said cleaning fluid chamber and said nozzle are hydraulically connected in series, that is to say in line, and in that cleaning fluid is discharged from said nozzle only when said image sensor housing reaches said second position.
In this event, said fluid nozzle may be covered by said image sensor housing itself in the first position, and said fluid nozzle may be uncovered and released by the image sensor housing itself in the second position.
For example, said nozzle may be formed by a nozzle duct which is integrated in the casing or which is part of the casing, the duct communicating with said fluid chamber by a bypass channel, which is closed in said first position of the image sensor housing, and which is open in said second position of said image sensor housing. The bypass channel may be hermetically closed by the image sensor housing itself in the first position.
The image sensor housing and/or casing may be provided with one or more sealing elements, for instance in the form of elastomeric sealing rings.
Generally, the image sensor housing may have a cylindrical cross-section. In that event, the casing also has a cylindrical cross-section, so that the image sensor housing defines a piston, whereas the casing defines the corresponding cylinder.
The image sensor housing may be designed as a cylindrical piston with an open bottom facing away from the external vehicle body surface. In that event the fluid chamber may be designed as an annular chamber formed by an annular space between the cylindrical casing and the image sensor housing.
Alternatively, the image sensor housing may include a piston rod and a piston surface, the later advantageously forming the bottom of the cleaning fluid chamber.
In one advantageous embodiment of the integrated on board vision and cleaning system according to the invention, the fluid nozzle (one or more fluid nozzles) is integrated in a connector for a cleaning fluid conduit, the connector being inserted in a opening of the casing or the connector being integral with the casing.
“Integrated” in that sense does not necessarily mean that the fluid nozzle and the connector are in one piece. The fluid nozzle may be for example designed as an eyeball snap-fitted into a corresponding compartment of the connector. The connector may be in the form of a fitting with a fir-tree profile.
Generally, the integrated on board vision and cleaning system according to the current application may be vehicle-mounted such that a lens dome or a dome-shaped lens cover faces slightly downwardly in the mounting position, so that surplus cleaning fluid may automatically be drained by gravity. As already mentioned, the system may also include at least one air nozzle in order to blow away surplus cleaning fluid.
Alternatively, or additionally, the system may include additional draining means for draining surplus cleaning fluid eventually collecting on the image sensor housing.
The system preferably includes at least two cleaning fluid nozzles arranged equally spaced apart at the periphery of the casing. The fluid nozzles are preferably facing or aiming radially inward into the inside of the casing.
As already mentioned, the image sensor housing may include a lens dome covering or even constituting a wide angle lens of the image sensor unit. The angle of view might be between 90° and 180°. A skilled person in the art will appreciate that the angle of view which as actually being displayed on the video monitor display inside the car in the end depends on the aspect ratio of the monitor display.
The invention hereinafter will be described by way of example with reference to the accompanying drawings in which:
Turning now to
Hereinafter the vehicle vision device including a sensor unit 6 for the sake of simplicity is referred to as the rear view camera 5.
The rear view camera 5 is mounted in an opening 7 of a vehicle body 8. The vehicle body 8 may be part of a bumper of a passenger car or of a hatch of a passenger car. The vehicle body 8 has an external vehicle body surface 9, which is exposed to ambient atmosphere.
To be more specific, the system includes an image sensor housing 10 being arranged in a vehicle body mounted casing 11. The image sensor housing 10 houses the image sensor unit 6 for instance comprising a CCD or CMOS Sensor and an optical system, for example a lens.
The image sensor housing 10 includes a translucent lens dome 13 facing outwardly, i.e. defining the sensor or camera coverage.
The image sensor unit 6 may be arranged within the image sensor housing 10 in a sealed fashion. The image sensor housing 10 itself is water-proof. Reference numeral 14 designates the wire to and from the image sensor unit 6, the wire 14 connecting the image sensor unit 6 to on board electronics of the passenger car.
The image sensor housing 10 according to the embodiment as shown in
In the embodiment as shown in
As this is shown in
Moreover, in the cleaning fluid conduit 4 upstream of the fluid nozzles 16, there are arranged two pressure retaining valves 18 including a valve body 19, which can be lifted from associated valve seat 20 by the pressure of the cleaning fluid, which is actually in the embodiment as described a cleaning liquid. The valve body 19 is held in the valve seat 20, for example by a spring, which is not shown.
Again, turning to
In the position shown in
Again, the piston rod 25 is sealed in the lead-through 26 by another O-ring seal 27. The seals, of course, could be any type of seal.
The function of the integrated on board vehicle vision and cleaning system according to the first embodiment as shown in
The cleaning fluid pump 1 which delivers at a fluid exit port 28 a liquid cleaning fluid with a pressure of 3 to 5 bar pumps the cleaning fluid from the cleaning fluid source into the cleaning fluid conduit 4 towards the fluid nozzles 16 and towards the fluid chamber 17 at the same time. The system preferably operates between 2 to 5 bar, but could operate below 2 or above 5 bar. The pressure retaining valves 18 at that time are closed. The pressure retaining valves 18 will open at a fluid pressure of about 1.5 to 2.5 bar. Optimum valve opening pressure is 1 to 2 bar, but could be below 1 bar or above 2 bar.
The spring constant of the coil spring 21 is chosen such that pressurizing in the fluid chamber 17 by a static pressure of the cleaning fluid of about 0.5 to 1.5 bar, preferably 0.8 bar will be sufficient to move the image sensor housing 10 against the biasing force of the coil spring 21 into the position as shown in
b show a second embodiment of the integrated on board vehicle vision and cleaning system according to the present invention. Same parts are denoted by the same reference numerals.
For the sake of simplicity, hereinafter it will be referred only to the differences between the two embodiments.
First of all, the casing 11 has only two connectors 15a, 15c, since the fluid nozzles 16 are integrated into the casing and may be simply provided as slots 29 in the casing 11. The casing 11 may have an annular space forming a liquid distribution chamber opening into several slots 29. Alternatively, only one slot may be present. The connectors could either be integrated or assembled as separate parts.
Moreover, the image sensor housing 10 is designed as an open-ended cylinder forming with the casing 11 an annular space defining the fluid chamber 17. The annular space is sealed by two axially opposing sealing rings 30, each sealing ring 30 having two flexible sealing legs 31. The sealing rings 30 have a kind of V-profile and are arranged such that the open sides of the profile are facing each other with the result that the fluid entering the fluid chamber will force the sealing legs 31 against an inner cylindrical wall of the casing 11, thus, providing proper sealing. The V-type seal could also be replaced by other types of seals including O-rings. V-type is the preferred seal.
It is to be understood that in all of the embodiments shown herein the casing 11 and the image sensor housing 10 are cylindrical parts, even though they may have another geometry.
The advantage of the solution shown in the second embodiment vis-à-vis the solution shown in the first embodiment is that the image sensor unit 6 may be inserted from the open end of the image sensor housing 10 into the later, i.e. from the side facing away from the external vehicle body surface 9.
In both embodiments the wire 14 connecting the image sensor unit 6 is not shown. For guiding the wire to the onboard electronics, there is a lead-through 32 in the closure cap 23.
For the sake of simplicity, in
At the beginning of the cleaning cycle again the image sensor housing 10 is in the position as shown in
As cleaning fluid enters the fluid chamber via the connector 15c opening into the fluid chamber 17, the image sensor housing 10 moves into the retracted position (second position) as shown in
Once the cleaning fluid pump 1 is deactivated, the image sensor casing moves back into the position as shown in
A person skilled in the art will appreciate that in the inwardly facing wall of the annular space 33, several slots at equal distance at the circumference of the cylinder defined by the casing 11 may be provided.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2014 010 495.8 | Jul 2014 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/064879 | 6/30/2015 | WO | 00 |
