GB2469738A

GB2469738A - Vehicle windscreen-mounted wireless camera for detecting road traffic signs

Info

Publication number: GB2469738A
Application number: GB1006609A
Authority: GB
Inventors: Henryk Bury
Original assignee: Bury Sp zoo
Current assignee: Bury Sp zoo
Priority date: 2009-04-23
Filing date: 2010-04-21
Publication date: 2010-10-27
Also published as: GB201006609D0; AU2010201545A1; DE102009018515A1; IL205213A0

Abstract

Vehicle-mounted image capture device, such as a camera, that identifies, evaluates and classifies image elements, such as road signs, and wirelessly transmits a signal indicative of the image element to a receiver that matches the signal to a memory-stored library symbol which is displayed on a screen. The image processor may detect road traffic signs such as maximum speed limit signs. A GPS module may allow the vehicle's instantaneous speed to be determined from satellite position data and this speed may be compared with the detected road speed limit and an optical and audible warning signal may be initiated if the speed limit is exceeded. The camera may have first-in first-out (FIFO) memory which stores video images over a time period and overwrites them continuously with new images. The camera may be mounted in a bi-partite housing and pivoted depending on the angle of inclination of the vehicle's windscreen. The display may be part of a mobile telephone hands-free kit. The processor may also detect pedestrians and act as a road safety device.

Description

Camera device for use in a motor vehicle The invention relates to a camera device for use in a motor vehicle having a passenger compartment, with a housing for holding a camera sensor, which housing can be mounted with an orientation with respect to the road being travelled by the motor vehicle which is suitable for viewing through a windscreen, with evaluation electronics for image elements which are captured by the camera sensor, and with a display device for reproducing symbols which are stored in a memory, which can be selectively displayed on the display device and which correspond to the image elements which are captured by the camera sensor and are provided for display.

Such a camera device is known from EP 1 383 098 B1. The housing here is mounted with the camera sensor as an attachment on the dashboard of the motor vehicle. The arrangement is used to recognize road signs. The display device, which is configured for reproducing the symbols corresponding to the recognized road signs by virtue of the fact that it is provided with a library of possible road signs stored in a memory, is located in a central console. The display device is permanently stored in the motor vehicle and is connected to the motor vehicle's tachometer in order to compare the maximum permissible speed with the instantaneous speed at which the vehicle is travelling. Since the housing with the camera sensor has to be connected to the display device via a cable which is not visibly attached, the only possibility for positioning the camera is to arrange it directly on the upper side of the dashboard of the motor vehicle, as a result of which optimal positioning of the camera is problematic.

Furthermore, the camera housing has to be small in design so that it is not felt to have a disruptive effect on the view of the road either for the driver or the front seat passenger.

The camera can be more favourably positioned on the rear side of the interior rear view mirror of the motor vehicle. However, cabling of the display device is very complex here and has to be effected with a screened video cable to avoid disruption through radiation of interference signals into the transmission path to the evaluation device in the display device.

The present invention is based on the object of permitting better positioning of the camera and retrofitting of the camera device without the costly cabling.

In order to solve this problem, a camera device of the type mentioned at the beginning is characterized according to the invention in that the evaluation electronics are also arranged in the housing and are connected to an raterface for the wre1ess transmsson of signals which identify the evaluated image elements, and in that the display device is positioned spatially separated from the housing and is provided with a receiver for the signals which are transmitted in a wireless fashion, and with the memory for the stored symbo]s.

The camera device according to the invention therefore permits the camera sensor to be mounted in the direct vicinity of the windscreen at a location at which the housing which holds the camera sensor does not impede the vehicle occupants' view of the road. Such a location is situated, for example, at the upper edge of the windscreen, preferably behind the interior rear view mirror of the motor vehicle, which is known to be arranged in the middle of the width and in the upper region of the windscreen. The display device can be arranged at a suitable point in the passenger compartment of the motor vehicle in the driver's viewing angle, wherein cable routing is not required since the information from the camera sensor is transmitted in a wireless fashion. The wireless transmission becomes possible by virtue of the fact that according to the invention the image elements which are recorded by the camera sensor are not transmitted to the display device since a considerable transmission speed, which cannot in practice be implemented with economical devices, would have to be made possible for this. Instead, according to the invention the evaluation electronics for the image elements which are captured by the camera sensor and which are to be displayed are arranged in the housing on the camera sensor itself. The transmission to the display device therefore merely has to contain an encoded signal which characterizes the type of the image element captured by the camera sensor and can therefore be called by the display device from the memory of the stored symbols. All short-range transmission methods such as, for example, those according to the Bluetooth standard are suitable for the wireless transmission of the signal which characterizes the captured image element.

In one preferred embodiment of the invention, the housing is embodied with a transparent bearing face which can be attached to the inner side of a windscreen of the motor vehicle, wherein the bearing face is preferably attached by bonding. In this context, the problem arises that the inclination of the windscreen is vehicle-specific and therefore depends on the type of the vehicle and on the respective vehicle model.

Sporty vehicles which are designed to aerodynamic criteria have in this context a windscreen which has a very oblique position with respect to the vertical, while utility vehicles such as buses, minibuses, delivery vans etc. tend to be equipped with steep windscreens.

In order to solve this problem, the camera sensor can be arranged within the housing in such a way that it can pivot in relation to the bearing face so that it is always oriented in a suitable way with respect to the road in front of the vehicle even given different inclinations of the windscreen. The pivoting can take place here through a plurality of latched positions, so that a predefined latched position, which ensures the optimum orientation of the camera sensor, is set as a function of the inclination of the windscreen.

In another solution to the problem, the housing is embodied in at least two parts with an attachment part which has the bearing face, and a camera part which supports the camera sensor, wherein the camera part can be detachably connected to the attachment part in a fixed relative position, and the attachment part is embocLied ra a vefric1e-specilc manner with respect to the orientation of its bearing face such that the camera sensor is oriented suitably after the connection of the camera part to the attachment part. In this case, a specific attachment part is used for the respective vehicle type, which attachment part is provided on the windscreen, preferab]y by means of a bonded connection in the shape of a frame. Adapting the inclination of the bearing face to the inclination of the windscreen ensures that the section of the attachment part to which the camera part is preferably attached by latching on has the suitable orientation which ensures that the camera sensor is suitably oriented after the mounting of the camera part on the attachment part. The prescribed embodiments of the housing of the camera sensor are clearly also advantageous if no inventive wireless transmission of signals which have already been evaluated to the display device takes place but rather signals of the camera sensor are fed in an evaluated or even non-evaluated form to the display device by means of a cable, in which case the camera sensor can then also be supplied with power via the cable.

The camera sensor which is provided according to the invention can be made available for a further use in that a video image memory, which, as an FIFO memory, stores video images over a predefined time period and continuously overwrites them with new video images, is connected to the camera sensor in the housing. This ensures, that, for example, the video images which are recorded by the camera sensor in the last thirty minutes are stored in the memory, which may be significant in terms of clarifying the origins of a traffic accident, for example. If the recording is required, the further recording by the camera sensor has to end. For this purpose, it is possible to switch off the recording of new video images by means of a switch, wherein the switch can be activated manually or controlled by means of a sensor. In this context, in particular a crash sensor, such as is used for the triggering of air bags, is possible as the sensor.

In one preferred embodiment of the invention, the display device has an attachment device for retro-fitting in the passenger compartment of the motor vehicle. This attachment device may be, for example, an attachment foot which can be bonded on in the region of the dashboard and onto which the display device can be latched. In addition, an attachment foot which can be bonded onto a glass pane is possible, wherein the bonded connection can be made with a suitable region of the windscreen or a fixed part of a side window of the motor vehicle. In addition, the attachment of the attachment foot to, in particular, a glass pane can be carried out by means of a suction cup, allowing the bonded connection to be dispensed with.

In a further preferred embodiment of the invention, the camera device also comprises a satellite position-determining module and a reception antenna for said module. If, in one preferred embodiment of the invention, road signs are recognized with the camera sensor, the relative, precise, permanent determination of position of the motor vehicle which is possible with the position data can assist the recognition of the road signs by virtue of the fact that permanently installed road signs are stored in a memory of the display device for certain positions, that is to say for certain sections of a road, and they permit a display of a symbol on the display device even if visual capturing of the road sign by the camera sensor has been disrupted or entirely prevented, for example by a lorry which has overtaken at this point and obstructs the view of the road sign. The satellite positioning module, which can be formed by a GPS mouse, is preferably arranged on or Ira the housing of the camera sensor. In this context, information about road signs or the like which is stored in a memory interacts with the satellite positioning module in order to carry out a plausibility check of a road sign which has been recognized (with a certain degree of uncertainty), or, if the road sign has not been recognized, to substitute the stored information, if appropriate with a corresponding message, for the process of recognition of a road sign.

During the process of recognition of a road sign, the capturing of maximum permissible speeds which are displayed by the road signs is in the foreground. In this case, the display device can contain an evaluation device for determining the instantaneous speed of the motor vehicle from the received satellite position data, so that the instantaneous speed of the motor vehicle can be compared with the recognized maximum permissible speed in a comparison device. If the maximum permissible speed is exceeded by the detected instantaneous speed or exceeded by a predefined amount, an optical and/or acoustic warning signal is preferably output by the display device in order to remind the driver to keep to a speed which is adapted to the maximum permissible speed.

The camera arrangement according to the invention can also be used for recognizing pedestrians which are located in front of the motor vehicle in the direction of travel, and for outputting a corresponding warning.

It is preferred here that the recognition of the pedestrians be correlated with a process of determination of the speed on the basis of the satellite position data in order, for example, to suppress a warning about pedestrians when a vehicle is stationary. Furthermore, by evaluating the size of the recognized pedestrians, it is possible to relate an estimation of the distance of the pedestrians from the motor vehicle to a determined speed of the motor vehicle, in order to permit a reliable warning of danger.

The invention will be explained in more detail below on the basis of exemplary embodiments which are illustrated in the drawing, in which: Figures 1 a to c show the mounting of a housing according to a first embodiment of the invention on a windscreen of a motor vehicle, Figure 2 shows variants of the design of the housing, composed of an attachment part and a camera part, for various inclinations of the windscreen using vehicle-specific attachment parts, Figure 3 is a schematic illustration of a display device according to the invention which is at the same time a display device for a telephone hands-free device of the motor vehicle, Figures 4 a to c show a section through a housing for a camera sensor, mounted on a windscreen which has a large slope, a view of an adjustment device for the angle of the camera sensor within the housing and a view of the housing from the front, Figures 5 a and b show a section through the housing according to Figure 4, the latter being mounted on a steep windscreen, as well as a view of the adjustment device for the camera sensor, Figure 6 is a schematic illustration of the use of the camera device according to the invention for recognizing road signs.

Figure la) is a schematic, perspective view of a passenger compartment of a motor vehicle with a windscreen 1, an interior rear view mirror 2, which is attached to the windscreen, and a central console 3 with a multimedia device 4, wherein the central console projects into the region of a dashboard 5.

As is shown clearly by Figure la) an attachment part 6 of a two-part housing 7 (Figure lc)) is provided with a flexible attachment plate 8 for bonding attachment to the windscreen 1 in the region of the interior rear view mirror 2. For this purpose, the attachment plate 8 has an outer circumferential edge which is formed by a bonding strip 9 and forms an enclosed bonding frame with which the attachment plate 8 can be bonded to the windscreen 1 at its upper edge, as is clarified by Figures lb) and lc) Above the windscreen there is a car roof 10 in which customary passenger compartment lights 11 and associated switches 12 are attached.

Figure lc) shows that the attachment part 6 bears with a planar, transparent bearing face 13 against the windscreen 1. The attachment part 6 has an open design towards the side facing away from the windscreen 1 and can be supplemented, with respect to the housing 7, by a camera part 14 which can be detachably connected to the attachment part 6. The camera part 14 has in its interior a camera sensor 15 and circuit boards 16, 17, 18 on which camera electronics, evaluation electronics, a satellite navigation antenna and a satellite navigation module are arranged.

Figure 2 shows variants of attachment parts 6 which are designed in a vehicle-specific manner for different inclinations of the windscreens 1 on various vehicles.

For example, Figure 2a) illustrates a windscreen 1 with a steep incline for a sporty motor vehicle, Figure 2b) illustrates a windscreen 1 with a shallow incline for a touring saloon, and Figure 2c) illustrates a relatively steep windscreen 1 for an estate car. Accordingly, attachment parts 6, 6', 6'' are provided whose bearing faces 13 have correspondingly adapted inclinations.

Moreover, the attachment parts 6, 6', 6'' form annular receptacles 19 into which a lens 20 of the camera sensor 15 can be inserted and is held with an orientation which is suitable for observing the road in front of the motor vehicle. Moreover, the attachment part 6, 6', 6'' is provided with housing projections 22 which are directed rearwards and have an outwardly directed, circumferential annular bead 23 by means of -10 -which a housing projection 24 can be snapped on with an annular groove 25 of the camera part 14 which is open towards the inside, so as to form the entire housing 7.

The housing 7 is preferably attached to the windscreen 1 without a cable connection and with an autonomous power supply (battery) and contains evaluation electronics with which objects which are to be identified and which have been recorded by the camera sensor 15 are recognized. The evaluation electronics therefore detect whether and, if appropriate, which objects to be detected have been received by the camera sensor 15 and generate a corresponding recognition signal which can be transmitted with a transmitter arranged in the housing 7 to a display device in a wireless fashion.

Figure 3 shows an exemplary embodiment of a display device 26 for which a display of a telephone hands-free device is used. The display device 26 contains a display 27, preferably a liquid crystal display, on which telephone data, such as telephone directories, telephone numbers of received or dialled subscribers etc., can be displayed, by virtue of the integration into the telephone hands-free device. The display device 26 can be attached to a holder 28 which can be mounted in the motor vehicle and can be bonded, for example with a foot 29, onto the dashboard 5 in the passenger compartment of the motor vehicle. The mounting means 28 forms an electrical connection to the display device 26 via a contact arrangement 30, and can be connected via a cable 31 to a base unit 32, permanently installed in the car in such a way that it cannot be seen from the passenger compartment, of the hands-free device. In addition, a microphone 33 which is mounted at a suitable location in the passenger compartment and a loudspeaker cable 34 which leads to a loudspeaker (not illustrated) can be connected to the -11 -base unit 32. A further cable 35, which can be connected to the base unit 32, forms a connection to the vehicle electronics and transmits, for example, a mute-switching signal for a car radio if the reproduction of the radio station is to be interrupted due to a telephone call. In addition, the connection to an ignition signal is produced so that the base unit 32 of the hands-free device can detect whether or not the motor vehicle's ignition is switched on.

In addition to these functions as a display device 26, within a hands-free device the display device 26 according to the invention is also provided with a receiver for the signals which are transmitted in a wireless fashion by the camera unit in the housing 7.

Furthermore, the display device contains a memory (not illustrated) from which symbols for the representation on the display 27 of the display device 26 can be retrieved by means of the signals which are transmitted in a wireless fashion. This makes it possible to transmit, from the camera sensor to the display device 26, information relating to image contents which have been recorded by the camera sensor, without having to transmit huge quantities of data for video signals.

Figures 4 and 5 illustrate a further embodiment of a housing 7' for the camera sensor 15. The housing 7' is closed off from the windscreen 1 with the transparent bearing face 13, which is adjoined by a housing wall 36 which has a triangular vertical section. The housing 7' forms a circumferential edge 37, by which it can be bonded in a frame-like fashion to the windscreen 1.

Approximately in the region of the tip of the triangular housing wall 36, the camera sensor 15 is mounted with a sensor housing 38 in such a way that it can rotate about a rotational axis 39 which extends horizontally and in parallel with the windscreen 1. A locking mechanism in the form of an opposing toothing -12 -system 40 is arranged between the sensor housing 38 and the rotational axis 39 and forms, with a scale 41 which is connected to the sensor housing 38 and a pointer 42 which is connected to the rotational axis 39, a display for a rotational angle of the sensor housing 38 in relation to the rotational axis 39.

In Figure 4, the housing 7' is bonded to a windscreen with an extreme slope, so that the camera sensor 15 with its sensor housing 38 is pivoted far in the downward direction, as is shown in the enlarged illustration of the locking device 40 in Figure 4b.

In contrast, the housing 7' in the illustration in Figure 5 is bonded onto a very steep windscreen 1, SO that the sensor housing 38 has been pivoted far in the upward direction, in order to permit suitable horizontal orientation of the camera sensor 15. The pivoting position can be read off on the locking device 40, as indicated in Figure Sb) In the embodiment of the housing 7' and of the arrangement of the camera sensor 15 in a pivotable sensor housing 38 within the housing 7', as illustrated in Figures 4 and 5, a use for different angles of inclination of the windscreen 1 is possible because the camera sensor can be pivoted with the locking device 40 about the rotational axis 39 and into the suitable orientation.

In the embodiment illustrated in Figures 4 and 5, the housing 7' is therefore not configured in a vehicle-specific way in structural terms as is the case in the first embodiment with the vehicle-specific attachment parts 6, 6', 6'' Figure 6 symbolizes the function of the camera sensor for the recognition of road signs 41. The video images -13 -of the camera sensor 15 are evaluated in the evaluation device which is present in the housing 7, 7' so that it is detected that a road sign 41 which indicates a maximum speed of, in this case, "70" has been recognized. The evaluation device therefore generates a corresponding, encoded signal which is transmitted in a wireless fashion from the housing 7, 7' to the display device 26. In the display device 26, the received, encoded signal is used to retrieve a symbol from a memory which is represented on the display 27 of the display device 26 as a road sign indicating the maximum speed "70", so that the driver of the motor vehicle is informed as to which road sign has been recognized at a particular time.

Furthermore, if a satellite navigation device is provided in the display device 26, the display device 26 can calculate the instantaneous speed of the motor vehicle from the satellite position data and compare said speed with the maximum permissible speed detected on the basis of the recognized road signs 41.

By means of the display device 26 or by means of the connection of the display device 26 to the base unit 32, it is possible to transmit and reproduce an acoustic signal via the loudspeaker cable 34 and/or an optical signal can appear on the display 27 of the display device 26. Of course, other signal generators are also possible, with which signal generators the driver's attention is drawn to the fact that he is exceeding the maximum permissible speed, if appropriate by a predefined speed interval.

The camera arrangement according to the invention can also have, in the housing 7, 7', a memory device with which the signals of the camera sensor 15 are stored in an annular form in accordance with the memory capacity which is present, so that the last camera images for a specific interval are stored and can be used, for -14 -example, for clarifying the origins of an accident. In the case of an accident, the further storage should be stopped. This can be carried out in a manual fashion or under sensor control, for example by means of a crash sensor.

Claims

-15 -Patent claims 1. Camera device for use in a motor vehicle having a passenger compartment, with a housing (7, 7') for holding a camera sensor (15), which housing (7, 7') can be mounted with an orientation with respect to the road being travelled by the motor vehicle which is suitable for viewing through a windscreen (1), with evaluation electronics for image elements which are captured by the camera sensor (15), and with a display device (26) for reproducing symbols which are stored in a memory, which can be selectively displayed on the display device (26) and which correspond to the image elements which are captured by the camera sensor (15) and are provided for display, characterized in that the evaluation electronics are also arranged in the housing (7, 7') and are connected to an interface for the wireless transmission of signals which identify the evaluated image elements, arid Ira that the display device (26) is positioned spatially separated from the housing (7, 7') and is provided with a receiver for the signals which are transmitted in a wireless fashion, and with the memory for the stored symbols.
2. Camera device according to Claim 1, characterized in that the housing (7, 7') is embodied with a transparent bearing face (13) which can be attached to the inner side of the windscreen (1) of the motor vehicle.
3. Camera device according to Claim 1 or 2, characterized in that the camera sensor (15) is arranged within the housing (7, 7') in such a way that it can pivot in relation to the bearing face (13)
4. Camera device according to Claim 3, characterized in that the camera sensor (15) can be pivoted through a plurality of latched positions.-16 -
5. Camera device according to Claim 1 or 2, characterized in that the housing (7) is embodied in at least two parts with an attachment part (6, 6', 6'') which has the bearing face (13), and a camera part (14) which supports the camera sensor (15), in that the camera part (14) can be connected to the attachment part (6, 6', 6'') in a fixed relative position, and in that the attachment part (6, 6', 6'') is embodied in a vehicle-specific manner with respect to the orientation of its bearing face (13) such that the camera sensor (15) is oriented suitably after the connection of the camera part (14) to the attachment part (6, 6', 6'').
6. Camera device according to Claim 5, characterized in that the camera part (14) can be connected to the attachment part (6, 6', 6'') in a latching fashion.
7. Camera device according to one of Claims 1 to 6, characterized in that a video image memory, which, as an FIFO memory, stores video images over a predefined time period and continuously overwrites them with new video images, is connected to the camera sensor (15) in the housing (7, 7')
8. Camera device according to Claim 7, characterized in that the recording of new video images can be switched off by means of a switch.
9. Camera device according to Claim 8, characterized in that the switch can be activated manually.
10. Camera device according to Claim 8, characterized in that the switch can be controlled by a crash sensor.-17 -
11. Camera device according to one of Claims 1 to 10, characterized in that the display device (26) is a display of a telephone hands-free device.
12. Camera device according to one of Claims 1 to 11, characterized in that the display device (26) has an attachment device (28) for retrofitting in the passenger compartment of the motor vehicle.
13. Camera device according to one of Claims 1 to 12, characterized in that it comprises a satellite position-determining module and a reception antenna for said module.
14. Camera device according to Claim 13, characterized in that it also has an evaluation device for determining an instantaneous speed from the received satellite position data.
15. Camera device according to one of Claims 1 to 14, characterized in that the evaluation electronics which are connected to the camera sensor (15) are designed at least to recognize road signs (41), in particular those for displaying a maximum permitted speed.
16. Camera device according to Claims 14 and 15, characterized in that the display device (26) also has a comparison device for comparing the determined instantaneous speed with the recognized, maximum permissible speed.
17. Camera device according to one of Claims 1 to 16, characterized in that the evaluation electronics which are connected to the camera sensor (15) are designed to recognize pedestrians in front of the motor vehicle.
18. Camera device according to one of Claims 1 to 17, characterized in that the display device (26) is -18 -designed to trigger at least one optical and/or acoustic warning signal.