Image acquisition device and system for motor vehicles

Abstract

The present disclosure relates to an image acquisition device (10) for a motor vehicle, comprising: a connector (14), a first camera (11) arranged in a housing (15) so as to acquire images of a first zone (Z1) located on a first side of said housing, said first camera being configured to provide a first digital data stream / , a second camera (12) arranged in the housing so as to acquire images of a second zone (Z2) located on a second side of said housing, opposite the first side of said housing, said second camera being configured to provide a second digital data stream, a multiplexer circuit (13) arranged in the housing, configured to multiplex the first digital data stream and the second digital data stream so as to obtain a third digital data stream which is provided on the connector. Figure accompanying the abstract: Figure 1

Description

Title of the invention: Image acquisition device and system for motor vehicles Technical field

[0001] The present invention belongs to the field of image acquisition, and relates more particularly to an acquisition device and an image acquisition and processing system for motor vehicles. State of the art

[0002] Nowadays, motor vehicles are increasingly equipped with sensors, and in particular more and more cameras.

[0003] In particular, a motor vehicle may carry one or more cameras which observe towards the outside of the motor vehicle, used in particular to provide driving assistance functions (“Advanced Driver Assistance System”, AD AS, in the English literature). For example, it is known to place a camera in an upper part of the front windshield of said motor vehicle (generally substantially in the center of said windshield), directed towards the front of said motor vehicle, which may be used in particular by an advanced emergency braking system (“Advanced Emergency Braking System”, AEBS), by a lane keeping assistance system (“Lane Keeping Assist”, LKA) or lane departure warning system (“Lane Departure Warning”, LDW), by a traffic sign recognition system (“Traffic Sign Recognition”, TSR), etc.

[0004] A motor vehicle may also have one or more cameras which observe towards the interior of the motor vehicle. For example, it is known to place a camera in an upper part of the front windshield of said motor vehicle (generally substantially in the center of said windshield), directed towards the interior of said motor vehicle, which may be used in particular by a driver monitoring system (“Advanced Driver Distraction Warning”, ADDW), etc.

[0005] Thus, it may prove necessary to install separate cameras, used by different systems of the motor vehicle, in the upper part of the windshield of the motor vehicle, for example in the center of said windshield. The installation of separate cameras in the upper central part of the windshield can generate a significant amount of space which can reduce the driver's visibility, and which can also be accompanied by difficulties in passing the various cables necessary to operate and use these cameras.

[0006] Furthermore, there is also a general need to reduce the complexity and cost (of manufacturing and installation) of systems to be embedded in motor vehicles while maintaining the same level of functionality. Statement of the invention

[0007] The present invention aims to remedy all or part of the limitations of the solutions of the prior art, in particular those set out above.

[0008] To this end, there is proposed according to a first aspect an image acquisition device for a motor vehicle, comprising: - a connector, - a first camera arranged in a housing so as to acquire images of a first area located on a first side of said housing, said first camera being configured to provide a first digital data stream corresponding to images acquired by said first camera, - a second camera arranged in the housing so as to acquire images of a second area located on a second side of said housing, opposite the first side of said housing, said second camera being configured to provide a second digital data stream corresponding to images acquired by said second camera, - a multiplexer circuit arranged in the housing, connected to the first camera, to the second camera and to the connector, configured to multiplex the first digital data stream and the second digital data stream so as to obtain a third digital data stream which is provided on the connector.

[0009] Thus, it is proposed to place in the same housing a first camera and a second camera, which observe respective zones located on either side of the housing. By installing this housing in the upper part of the windshield of a motor vehicle, the first camera can therefore be directed towards the front of the motor vehicle (and be used for example by AD AS systems such as AEBS, LKA, LDW, TSR, etc.), while the second camera can be directed towards the interior of the motor vehicle (and be used for example by an ADDW system, etc.). The space requirement is therefore reduced since these two cameras are placed in the same housing where they were placed in separate housings in the solutions of the prior art.

[0010] Furthermore, thanks to the multiplexer circuit, the same connector is used to transmit the digital data streams provided by the first camera and by the second camera. The space requirement is therefore further reduced since a single connector can be used where two connectors were necessary in the solutions of the art. The wiring and installation of the box are also greatly facilitated compared to prior art solutions.

[0011] In particular embodiments, the image acquisition device may further comprise one or more of the following optional features, taken individually or in any technically possible combination.

[0012] In particular embodiments, the image acquisition device comprises an electrical distribution circuit configured to distribute electrical energy received by the connector to the first camera, the second camera and the multiplexer circuit.

[0013] Such arrangements make it possible to reduce the complexity, bulk and cost of the acquisition device compared to the solutions of the prior art, since the same connector is used to transmit the digital data streams and to receive the electrical energy necessary for the operation of the different equipment of said acquisition device.

[0014] In particular embodiments, the multiplexer circuit is configured to further perform a parallel / serial conversion.

[0015] In particular embodiments, the multiplexer circuit uses a serial communication protocol implemented on a low voltage differential signaling technology (“Low Voltage Differential Signaling” or LVDS in the English literature).

[0016] In particular embodiments, the digital data of the first stream and the second stream are raw data, transmitted via the connector to a processing circuit external to said image acquisition device.

[0017] Such arrangements make it possible to reduce the complexity, size and cost of the acquisition device compared to the solutions of the prior art. Indeed, since the digital data of the first stream and the second stream are raw data, it is not necessary to provide a complex image processing circuit inside the housing of the acquisition device. The bulk of the image processing can in fact be carried out in one or more remote processing circuits, for example integrated into a so-called high-performance computer (HPC), for example in a centralized architecture (the HPC being able to process digital data received from various equipment - cameras, actuators, sensors, etc. - of said motor vehicle).

[0018] According to a second aspect, there is provided an acquisition and processing system comprising an image acquisition device according to any one of the embodiments of the present disclosure and a computer external to said image acquisition device, the connector of said image acquisition device being connected to a connector of the computer, said computer comprising a demultiplexer circuit, configured to demultiplex the third digital data stream to obtain the first digital data stream and the second digital data stream, and at least one processing circuit configured to process the first digital data stream and the second digital data stream.

[0019] In particular embodiments, the image acquisition and processing system may further comprise one or more of the following optional features, taken individually or in any technically possible combination.

[0020] In particular embodiments, the demultiplexer circuit is configured to further perform a serial / parallel conversion.

[0021] In particular embodiments, the demultiplexer circuit uses a serial communication protocol implemented on LVDS technology.

[0022] According to a third aspect, there is provided a motor vehicle comprising an acquisition and processing system according to any one of the embodiments of the present disclosure.

[0023] In particular embodiments, the motor vehicle may further comprise one or more of the following optional features, taken individually or in all technically possible combinations.

[0024] In particular embodiments, the computer is also connected to other equipment of said motor vehicle.

[0025] In particular embodiments, the acquisition device is arranged at the front windshield of the motor vehicle with the first camera directed towards the front of said motor vehicle and the second camera directed towards the interior of said motor vehicle. Presentation of figures

[0026] The invention will be better understood on reading the following description, given by way of non-limiting example, and made with reference to the figures which represent: - [Fig.l] [Fig.l]: a schematic representation of an exemplary embodiment of an image acquisition device according to the present disclosure, - [Fig.2] [Fig.2]: a schematic representation of an example of arrangement of the acquisition device of [Fig.l] inside a motor vehicle, - [Fig.3] [Fig.3]: a schematic representation of an exemplary embodiment of an image acquisition and processing system according to the present disclosure.

[0027] In these figures, identical references from one figure to another designate identical or similar elements. For reasons of clarity, the elements shown are not to scale, unless otherwise indicated.

[0028] Furthermore, the order of steps shown in these figures is given solely as a non-limiting example of the present disclosure which may be applied with the same steps performed in a different order and / or with steps performed in parallel and / or jointly. Description of the embodiments

[0029] [Fig.l] schematically represents an exemplary embodiment of an image acquisition device 10 for a motor vehicle 20.

[0030] As illustrated by [Fig.l], the display device 10 comprises a housing 15 inside which are arranged a first camera 11 and a second camera 12 configured to observe the exterior of the housing 15. More particularly, the first camera 11 is configured to observe a first zone Z1 with respect to the housing 15, and the second camera 12 is configured to observe a second zone Z2 with respect to the housing 15, the first zone Z1 and the second zone Z2 being located on either side of the housing 15. In other words, the first zone Z1 and the second zone Z2 are located in different half-spaces with respect to said housing 15, not overlapping and separated by a virtual plane passing through said housing 15.

[0031] For example, the housing 15 comprises a first opening and a second opening, located on opposite faces of said housing 15. The first camera 11 comprises, for example, an optic located at said first opening, through which the first camera 11 observes the first zone Z1, and the second camera 12 comprises, for example, an optic located at said second opening, through which the first camera 11 observes the second zone Z2.

[0032] [Fig. 2] schematically represents an example of arrangement of the image acquisition device 10 in a motor vehicle 20. In this non-limiting example, the housing 15 of the acquisition device 10 is located in the upper part of the front windshield of the motor vehicle 20, for example in the center thereof (for example at the level of an interior rearview mirror) or in an upright of said front windshield. The housing 15 is arranged so that: - the first camera 11 is oriented towards the front of the motor vehicle 20, so that the first zone Z1 corresponds to an area located outside the motor vehicle 20, in front of the latter, - the second camera 12 is oriented towards the rear of the motor vehicle 20, so that the second zone Z2 corresponds to an area located inside the motor vehicle 20.

[0033] The first camera 11 and the second camera 12 preferably have different respective intrinsic and extrinsic optical parameters. For example, the second camera 12 may have a wider field of view than that of the first camera. 11. For example, the first camera 11 may have a field of view with a width of between 80° and 120°, while the second camera 12 may have a field of view with a width of between 140° and 180°. Alternatively or in addition, the second camera 12 may have a smaller maximum depth of field than that of the first camera 11. For example, the first camera 11 may have a maximum depth of field of the order of a few tens of meters to a few hundred meters (to see far ahead of the motor vehicle 20), while the second camera 12 may have a maximum depth of field of the order of a few meters (to see the passengers of the motor vehicle 20).

[0034] More generally, it is possible to consider other positions of the image acquisition device 10 making it possible to have the first camera 11 directed towards the outside of the motor vehicle 20 (for example towards the front thereof) and the second camera 12 directed towards the inside of said motor vehicle 20. The choice of a particular position of the acquisition device 10 in the motor vehicle 20 corresponds only to a non-limiting variant of implementation of the present disclosure. As indicated above, such arrangements make it possible to have in the same housing 15 cameras which can be used by different systems (for example by an AD AS system, such as AEBS, LKA, LDW, TSR, etc., for the first camera 11; for example by an ADDW system, etc., for the second camera 12).

[0035] The first camera 11 is configured to provide a first digital data stream corresponding to images of the first zone Z1. Similarly, the second camera 12 is configured to provide a second digital data stream corresponding to images of the second zone Z2.

[0036] As illustrated in [Fig. 1], the image acquisition device 10 also comprises a multiplexer circuit 13 arranged in the housing 15. The multiplexer circuit 13 comprises two input ports connected to the first camera 11 and to the second camera 12, respectively, and is configured to multiplex the first digital data stream (provided by the first camera 11) and the second digital data stream (provided by the second camera 12) so as to obtain a third digital data stream. The multiplexer circuit 13 comprises an output port connected to a connector 14 of the housing 15, via which the multiplexer circuit 13 transmits the third digital data stream to equipment external to the housing 15.

[0037] Generally speaking, any type of multiplexing making it possible to provide digital data streams from different input ports on the same output port can be implemented, and the choice of a particular type of multiplexing only corresponds to a non-limiting variant of implementation of the present disclosure. Such arrangements make it possible to reduce the number of connectors and cables required. to transmit the first stream and the second stream to external equipment. In preferred embodiments, the first stream and the second stream are time-division multiplexed. For example, the multiplexer circuit 13 may perform a parallel / serial conversion of the digital data received on the input ports, so that the transmission of the third stream of digital data to the equipment external to the housing 15 (via the connector 14) is a serial transmission. In preferred embodiments, this serial transmission uses low voltage differential signaling (LVDS) technology. Different serial communication protocols may be used based on LVDS technology, and the choice of a particular serial communication protocol is only a non-limiting variant of implementation of the present disclosure.For example, it is possible to use a serial communication protocol such as the GMSL protocol ("Gigabit Multimedia Serial Link"), or the FPD-Link protocol ("Fiat Panel Display Link"), etc.

[0038] In preferred embodiments, the power supply of the acquisition device 10 is provided via the cable connected to the connector 14. In other words, the same connector 14 and the same cable are used both to transmit (and possibly receive) digital data and to receive electrical energy to power in particular the first camera 11, the second camera 12 and the multiplexer circuit 13. In such embodiments, and as illustrated by [Fig. 1], the image acquisition device 10 further comprises an electrical distribution circuit 16. The electrical distribution circuit 16 is connected to the first camera 11, to the second camera 12, to the multiplexer circuit 13 and to the connector 14, and is configured to distribute electrical energy received via the connector 14 to the first camera 11, the second camera 12 and the multiplexer circuit 13.The electrical distribution circuit 16 may comprise, for example, in a conventional manner, electrical lines (tracks, cables, etc.), voltage adaptation circuits, etc.

[0039] In order to further reduce the quantity, complexity and bulk of the acquisition device 10, it is also possible, in certain exemplary embodiments, to limit the quantity of processing applied to the digital data provided by the first camera 11 and the second camera 12, and to carry out most of the processing to be applied (in particular for the needs of an AEBS, LKA, LDW, TSR system, etc., for the first camera 11, or of an ADDW system, etc., for the second camera 12) in a computer 31 external to the acquisition device 10. Thus, in these exemplary embodiments, the digital data of the first stream and of the second stream are for example raw data, transmitted, via the connector 14, to one or more processing circuits of a computer 31 external to the image acquisition device 10. The processing applied by the acquisition device 10 can then be limited to form processing strictly necessary to transmit the first stream and the second stream of digital data via the connector 14. These form processings (for example converting the digital data streams to GMSL format on LVDS) are for example carried out by the multiplexer circuit 13. More complex processings, in particular background processings aimed at analyzing the content of the images acquired by the first camera 11 and the second camera 12 to extract information therefrom (detection of traffic lane change, detection of traffic signs, obstacle detection, detection of driver drowsiness, etc.) can be carried out at the level of the remote computer 31.In such embodiments, the requirements in terms of computing capacity at the acquisition device 10 are therefore very limited, which makes it possible to reduce the complexity and the size of the components to be embedded in the housing 15 of said image acquisition device 10. The size can be reduced even more since the reduction in computing capacity is accompanied by a reduction in the requirements in terms of heat dissipation, so that it is possible to use less bulky heat dissipation means (radiator, etc.).

[0040] [Fig. 3] schematically represents an exemplary embodiment of a system 30 for acquiring and processing images for a motor vehicle 20.

[0041] As illustrated by [Fig. 3], the acquisition and processing system 30 comprises an image acquisition device 10 as described previously with reference to [Fig. 1]. For example, the acquisition device 10 is installed in the motor vehicle 20 in the position illustrated by [Fig. 2], that is to say in the upper part of the front windshield (for example in the center or in a pillar), with the first camera 11 directed towards the front of the motor vehicle 20 and the second camera 12 directed towards the interior of said motor vehicle.

[0042] As illustrated by [Fig. 3], the acquisition and processing system 30 further comprises a computer 31 external to the acquisition device 10, comprising a connector 314 connected to the connector 14 of the acquisition device 10 by wiring means 32. The wiring means 32 correspond for example to a coaxial cable or a twisted pair. Preferably, the wiring means between the acquisition device 10 and the computer 31 consist of a single coaxial cable or a single twisted pair. The computer 31 is also on board the motor vehicle 20.

[0043] As illustrated by [Fig. 3], the computer 31 comprises a demultiplexer circuit 310, configured to demultiplex the third digital data stream, i.e. to extract the first digital data stream and the second data stream digital multiplexed in the third stream received from the acquisition device 10. The demultiplexer circuit 310 can also perform, in certain examples, a serial / parallel conversion, in particular if the multiplexer circuit has performed a parallel / serial conversion.

[0044] In this exemplary embodiment, the computer 31 also comprises at least one processing circuit 311, 312 configured to process the first digital data stream and the second digital data stream. In the non-limiting example illustrated by [Fig. 3], the computer 31 comprises a first processing circuit 311, used to process the images received from the first camera 11, and a second processing circuit 312 used to process the images received from the second camera 12. The computer 31 may also comprise, in other exemplary embodiments, a different number of processing circuits. In particular, it is possible in certain exemplary embodiments to have a single processing circuit which processes both the images received from the first camera 11 and the images received from the second camera 12.

[0045] Each processing circuit 311, 312 comprises for example one or more processors (CPU, DSP, GPU, FPGA, ASIC, etc.) and one or more memories (magnetic hard disk, electronic memory, optical disk, etc.) in which is for example stored a computer program product, in the form of a set of program code instructions to be executed by the processor(s) to implement all or part of the processing to be carried out on the images received from the image acquisition device 10.

[0046] In certain examples, the computer 31 may be part of a centralized architecture, that is to say that it may also be connected to other equipment of the motor vehicle 20 (other cameras, actuators, sensors, etc.) to process the digital data received from this equipment and / or to control this equipment, etc. For example, the computer 31 is a high-performance computer (HPC).

[0047] More generally, it should be noted that the implementation and embodiment modes considered above have been described as non-limiting examples, and that other variants are consequently conceivable.

[0048] In particular, the acquisition and processing system 30 has been described by considering, in a non-limiting manner, a computer 31 embedded in the motor vehicle 20. However, nothing precludes, according to other examples, having a computer 31 entirely or partially remote from said motor vehicle. In particular, in certain exemplary embodiments, some of the processing to be applied to the images received from the acquisition device 10 may be carried out by a server remote from the motor vehicle 20, with which the computer 31 can exchange data via a wireless communication network.

Claims

Claims

1. Image acquisition device (10) for a motor vehicle (20), comprising: - a connector (14), - a first camera (11) arranged in a housing (15) so as to acquire images of a first zone (Z1) located on a first side of said housing, said first camera being configured to provide a first stream of digital data corresponding to images acquired by said first camera, - a second camera (12) arranged in the housing so as to acquire images of a second zone (Z2) located on a second side of said housing, opposite the first side of said housing, said second camera being configured to provide a second stream of digital data corresponding to images acquired by said second camera, - a multiplexer circuit (13) arranged in the housing, connected to the first camera, to the second camera and to the connector,configured to multiplex the first digital data stream and the second digital data stream to obtain a third digital data stream which is provided on the connector.,

2. An image acquisition device (10) according to claim 1, comprising an electrical distribution circuit (16) configured to distribute electrical energy received by the connector to the first camera, the second camera and the multiplexer circuit.

3. An image acquisition device (10) according to any preceding claim, wherein the multiplexer circuit is configured to further perform a parallel / serial conversion.

4. An image acquisition device (10) according to any preceding claim, wherein the multiplexer circuit uses a serial communication protocol implemented on low voltage differential signaling technology.

5. An image acquisition device (10) according to any preceding claim, wherein the digital data of the first stream and the second stream are raw data, transmitted via the connector to a processing circuit external to said image acquisition device.

6. Acquisition and processing system (30) comprising an image acquisition device (10) according to any one of the preceding claims and a computer (31) external to said image acquisition device, the connector of said image acquisition device being connected to a connector of the computer, said computer comprising a demultiplexer circuit (310), configured to demultiplex the third digital data stream so as to obtain the first digital data stream and the second digital data stream, and at least one processing circuit (311, 312) configured to process the first digital data stream and the second digital data stream.

7. The system (30) of claim 6, wherein the demultiplexer circuit is configured to further perform serial / parallel conversion.

8. The system of claim 6 or 7, wherein the demultiplexer circuit uses a serial communication protocol implemented on low voltage differential signaling technology.

9. Motor vehicle (20) comprising an acquisition and processing system (30) according to any one of claims 6 to 8.

10. Motor vehicle (20) according to claim 9, wherein the computer is also connected to other equipment of said motor vehicle.

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