CAMERA FOR A VEHICLE VISION SYSTEM

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a camera for a vision system of a motor vehicle. More particularly the invention relates to a camera with an active illumination comprising a single current-carrier line supply source.BACKGROUND OF THE INVENTION

[0002] Cameras comprising a current-carrier line supply source are generally used in motor vehicle, wherein data to control the camera and the power supply of the camera are carried by a coaxial cable connected to the camera. When light source are integrated inside the camera, control of the light source and power supply of the light source are remotely arranged from the camera such that extra wires connected to the camera, in addition with the coaxial cable, are necessary.

[0003] Such extra connections of the camera relative to the light source are necessary to prevent disturbance of the power supply of the imager integrated circuit of the camera and failures on the signals data of the camera that may result from the inrush current of the light source, and from conducted emissivity over power supply of the light source.

[0004] However, the extra connections are not a suitable solution as increasing the size of the camera and increasing the complexity of the electrical harness of the motor vehicle.

[0005] It is therefore important to propose a new solution to solve these problems.

[0006] In this regard, document US 2016 / 072991 Al discloses an illumination apparatus with integrated power and secondary illumination provisions. US 2016 / 198151A1 discloses a device for monitoring the functioning of a camera including a light source array. US 2018 / 109755A1 discloses a vehicle camera with an illumination unit using power over coax.

[0007] KR 2011 0127804A discloses a camera wherein an energy storage component provides an input voltage to an illumination unit.

[0008] JP 2018 018782A discloses a LED strobe light with a constant current source feeding an energy storage component and providing input voltage to an illumination unit.SUMMARY OF THE INVENTION

[0009] According to one embodiment, the invention relates to a camera for a motor vehicle configured to communicate with an electronic control unit (ECU) of the motor vehicle according to the appended claims 1-7 and comprising: an imager integrated circuit configured to capture images from the motor vehicle inside or outside environment; an illumination unit in electrical communication with the imager integrated circuit (22), said illumination unit (28) comprising at least one light source component, the illumination unit being configured to illuminate the inside / outside environment of the motor vehicle; a first mixer / splitter interface unit in electrical communication with the imager integrated circuit; a camera bidirectional signal port in electrical communication with the first mixer / splitter interface unit, said camera bidirectional signal port being configured to be electrically connected with an external power supply signal carrying data control signal for the imager integrated circuit; said first mixer / splitter interface unit being: configured to split the data control signal from the external power supply signal and to provide the split data control signal to the imager integrated circuit, configured to provide images data from the imager integrated circuit mixed with the external power supply signal to the camera bidirectional signal port.

[0010] Further, the first mixer / splitter interface unit is in electrical communication with the illumination unit and comprises: a first voltage regulator element to provide a first input voltage from the split external power supply signal to the imager integrated circuit, and a second voltage regulator element to provide a second input voltage, distinct from the first input voltage, from the split external power supply signal to the illumination unit.

[0011] The second voltage regulator element comprises a constant current source and an energy storage component configured to be fed by the constant current source, said energy storage component being configured to provide the second input voltage to the illumination unit.

[0012] The illumination unit comprises a light source failure detection component configured to diagnose a short circuit and / or open circuit of the light source component to get light source component diagnostic data, said light source failure detection component being configured to provide the light source component diagnostic data to the imager integrated circuit, and said first mixer / splitter interface unit being configured to provide the light source component diagnostic data mixed with the split external power supply signal from the imager integrated circuit to the camera bidirectional signal port.

[0013] The first mixer / splitter interface unit may comprise a first power over coaxial (PoC) filter element in electrical communication with the camera bidirectional signal port, said first PoC filter element being configured to split the data control signal from the external power supply signal and to provide the split data control signal to the imager integrated circuit. The first voltage regulator element and the second voltage regulator element are preferably comprised in the first mixer / splitter interface unit and are both in electrical communication with the first PoC filter element.

[0014] The first PoC filter element may be further configured to mix the images data with the external power supply signal.

[0015] The illumination unit may comprise a light source driver configured to control the illumination of the light source component. The light source component may be an infrared light source component. The light source driver may be configured to provide a pulsed power signal to the light source component such that the light source component provides a pulsed illumination.

[0016] The imager integrated circuit may comprise a trigger pin in electrical communication with the illumination unit, the imager integrated circuit being configured to trigger the illumination unit.

[0017] According to one embodiment of the invention, a vision system for a motor vehicle according to the appended claim 8 that comprises the camera as described above. The vision system further comprises an ECU comprising: an ECU bidirectional signal port, a second mixer / splitter interface unit in electrical communication with the ECU bidirectional signal port, the external power supply signal in electrical communication with the second mixer / splitter interface unit, a microcontroller configured to provide the data control signal to the second mixer / splitter interface unit.

[0018] The vision system further comprises a coaxial cable connected at one extremity end to the ECU bidirectional signal port, and at the second extremity end to the camera bidirectional signal port. The second mixer / splitter interface unit is configured to provide the data control signal mixed with the external power supply signal to the ECU bidirectional signal port such that the coaxial cable is configured to electrically carrying the external power supply signal mixed with the data control signal. The second mixer / splitter interface unit is configured to receive the images data mixed with the external power supply signal carried by the coaxial cable; and to split the images data from the external power supply in order to provide the images data to the microcontroller.BRIEF DESCRIPTION OF THE DRAWING

[0019] Other features, objects and advantages of the invention will become apparent from reading the detailed description that follows, and the attached drawing, given by way of example and in which: Figure 1 is a schematic diagram of a vision system of a motor vehicle according to one embodiment of the invention. DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENTS

[0020] According to figure 1, a vision system 10 for a motor vehicle 12 is shown. The vision system 10 can be used either for the external vision of the motor vehicle 10 such as for lanes monitoring system, for road signs monitoring system, as for the internal vision of the motor vehicle 12 such as for driver monitoring system. The vision system 10 may be also either used for automated vehicles i.e. driverless vehicles, than for manual vehicles wherein a driver controls the motor vehicle 12. The vision system 10 may be also used for advanced driver-assistance systems of a motor vehicle 12.

[0021] Even if not represented, it makes clear that the vision system 10 may be connected with some devices of the motor vehicle 12 such as braking system, steering wheel system, warning systems and others...

[0022] According to the invention, the vision system 10 comprises a camera 14 configured to monitor the outside of the motor vehicle 12 or the body compartment of the motor vehicle 12. The vision system 10 further comprises an electronic control unit (ECU) 16 configured to control the camera 14 and to process images captured by the camera 14. The vision system 10 further comprises only a one wire connection 19 between the ECU 16 and the camera 14. More particularly, the camera 14 has only a one wire connection 19 that has to carry the power supply 15 of the camera 14 and the signals data 17, exchanged between the camera 14 and the ECU 16, such as data control 31 sent from the ECU 16 to the camera 14 and images data 33 or video data sent from the camera 14 to the ECU 16. More particularly, the signals data 17 are carried by the power supply 15 signal such that the one wire connection 19 is a current-carrier line supply source.

[0023] The one wire connection 19 is part of a coaxial cable 18 connected at one extremity end to the ECU 16 and at the second extremity end to the camera 14. The camera 14, the ECU 16 and the coaxial cable 18 are grounded to a common electrical ground 21 that may be the body of the motor vehicle 12. Generally, the vision system 10 is supplied by a voltage source 20 that may be a battery of the motor vehicle 12. The voltage source 20 is generally directly connected to the ECU 16 such that the ECU 16 is configured to provide the power supply 15 of the camera 14.

[0024] The camera 14 that is configured to communicate with the ECU 16 comprises an imager integrated circuit 22 configured to capture the images from the motor vehicle 12 inside or outside environment. The imager integrated circuit 22 receives images from the field of view 26 of the lens 24 of the camera 14.

[0025] The camera 14 further comprises an illumination unit 28 comprising at least one light source component 30, the illumination unit 28 being configured to illuminate the inside / outside environment of the motor vehicle 12 monitored by the camera 14.

[0026] One particular aspect of the invention is that the power supply 15 signal of the camera 14 carried by the one wire connection 19 is used for supplying the imager integrated circuit 22 and the illumination unit 28. The power supply 15 of the camera 14 is a single power supply 15 for the camera 14.

[0027] Preferably, the illumination unit 28 comprises a plurality of infrared light-emitting diodes such that the light is not visible by a driver or a passenger of the motor vehicle 12. The infrared light source component 30 is especially used when the camera 14 illuminates the face of the driver in order to not blind the driver.

[0028] As shown in figure 1, in order to get control and / or diagnostic of the light source component, the illumination unit 28 comprises a light source driver 32. According to one embodiment, to save energy from the vision system 10, and more particularly to the illumination unit 28, the light source driver 32 provides a pulsed power supply signal to the light source component 30, as for example, with a 50% duty cycle such that current consumption over the light source component 30 is divided by two. Providing a pulsed power supply signal to the light source component 30 results in a pulsed illumination of the field of view 26 of the camera 14.

[0029] According to one embodiment, the imager integrated circuit 22 is in electrical communication with the illumination unit 28. More particularly, the imager integrated circuit 22 is able to provide a trigger signal to the illumination unit 28 such that the illumination of the field of view is synchronized with the capture of the images by the imager integrated circuit 22. In addition, the light source driver 32 comprises a light source failure detection component able to diagnose a short circuit of the light source component 30, i.e. an over current consumption of the light source component 30. The light source failure detection component is further able to diagnose an open circuit of the light source component 30, i.e. a detection of a zero current consumption of the light source component 30 after the trigger signal of the imager integrated circuit 22.

[0030] According to the invention, the camera 14 comprises a first mixer / splitter interface unit 34 in electrical communication with the imager integrated circuit 22 and in electrical communication with the illumination unit 28. The first mixer / splitter interface unit 34 is in electrical communication with the one wire connection 19 by a camera bidirectional signal port 36. The camera bidirectional signal port 36 is connected to the coaxial cable 18 such that the camera bidirectional signal port 36 is configured to provide the power supply 15 of the camera 14 and the data control 31 signal from the ECU 16 to the first mixer / splitter interface unit 34. According to figure 1, the power supply 15 of the camera 14 is a power supply 15 external from the camera 14, said power supply 15 being provided by the ECU 16. More generally, the power supply 15 of the camera 14 may be any external power supply 15 wherein the power supply 15 signal is carrying the signals data 17 exchanged between the camera 14 and the ECU 16.

[0031] The first mixer / splitter interface unit 34 is configured to split the data control 31 signal from the power supply 15 of the camera 14 and to provide the split data control 31 signal to the imager integrated circuit 22. The first mixer / splitter interface unit 34 is further configured to provide the images data 33 from the imager integrated circuit 22 mixed with the power supply 15 signal of the camera 14 to the camera bidirectional signal port 36. The first mixer / splitter interface unit 34 is further configured to provide diagnostic data 29 of the light source component 30 from the imager integrated circuit 22 mixed with the split power supply 15 signal to the camera bidirectional signal port 36.

[0032] In addition, the first mixer / splitter interface unit 34 is configured to distribute the power supply 15 of the camera 14 to the imager integrated circuit 22 and to the illumination unit 28. Accordingly, the first mixer / splitter interface unit 34 is configured to provide a first input voltage 23 from the split power supply 25 of the camera 14, i.e. split from the data control 31 signal, to the imager integrated circuit 22, and to provide a second input voltage 27, distinct from the first input voltage 23, from the split power supply 25 of the camera 14 to the illumination unit 28.

[0033] The first input voltage 23 and the second input voltage 27 are distinct in the sense of the invention such that they are electrically isolated from each other in order to prevent disturbances on the first input voltage 23 coming from the second input voltage 27, wherein, the second input voltage may causes conductive electromagnetic disturbances and drop of current respectively due to pulsed power supply signal of the light source component 30 and due to inrush current of the light source component 30.

[0034] As non-limitative example, the first mixer / splitter interface unit 34 comprises a first voltage regulator element 40 configured to provide the first input voltage 23 to the imager integrated circuit 22 from the split power supply 25. Generally, the first voltage regulator element 40 is a buck or a boost voltage conversion device that provides the necessary stabilized voltage for the imager integrated circuit 22. In addition, in order to protect the first input voltage against the effect of the light source power supply, the first mixer / splitter interface unit 34 comprises a second voltage regulator element 42 configured to provide the second input voltage 27 to the illumination unit 28 from the split power supply 25. More particularly, the second voltage regulator element 42 comprises a constant current source 44 and an energy storage component 46 configured to be fed by the constant current source 44, said energy storage component 46 being configured to provide the second input voltage to the illumination unit 28. The energy storage component 46 may be a capacitor element designed to provide additional energy to the light source component 30 during inrush current phase of the light source component 30. In other words, the energy storage component 46 is advantageously able to provide, in a single pulse, more energy than can be instantaneously obtained from the power supply through the coaxial cable 18. Thanks to this energy storage component 46, a large amount of energy can be stored therein, before being released for supplying the light source driver 32 of the illumination unit 28. As a result, a significant pulsed current can be supplied to the light source 30 to generate a high brightness pulsed light. Thus, the light source 30 component becomes especially efficient, given that it can provide high illumination despite the limited power supplied through the coaxial cable 18. In this regard, it should be also noticed that any coaxial cable designed to carry both data signal and power supply cannot provide high pulsed energy because current pulses would disrupt the data communications.

[0035] The first mixer / splitter interface unit 34 comprises a first power over coaxial (PoC) filter element 48 in electrical communication with the camera bidirectional signal port 36, said first PoC filter element 48 being configured to split the data control 31 signal from the power supply 15 signal and to provide the split data control 31 signal to the imager integrated circuit 22. The first PoC filter element 48 is further configured to mix the images data 33 with the power supply 15 signal. The first PoC filter element 48 is further configured to provide the diagnostic data 29 from the imager integrated circuit 22 mixed with the power supply 15 signal of the camera 14 to the camera bidirectional signal port 36.

[0036] The first PoC filter element 48 is further configured to provide the split power supply 25 signal from the power supply 15 carrying the signals data 17 to the first voltage regulator 40 and to the second voltage regulator 42.

[0037] According to one embodiment of the invention, and to figure 1, the ECU 16 comprises the complementary electronic components for establishing a current-carrier communication with the camera 14 through the coaxial cable 18. Accordingly, the ECU 16 comprises an ECU bidirectional signal port 50 and a second mixer / splitter interface unit 52 in electrical communication with the ECU bidirectional signal port 50. The ECU 16 comprises the power supply 15 for the camera 14. The power supply 15 is provided by a third voltage regulator 54 of the ECU 16 electrically connected to the voltage source 20. More particularly, the third voltage regulator 54 is configured to provide an internal power supply 56 of the ECU 16, said internal power supply 56 being electrically connected to the second mixer / splitter interface unit 52.

[0038] The ECU 16 further comprises a microcontroller 58 configured to exchange the signals data 17 with the second mixer / splitter interface unit 52. Accordingly, the second mixer / splitter interface unit 52 is configured to provide the data control 31 signal mixed with the internal power supply 56 to the ECU bidirectional signal port 50 such that the ECU is configured to provide the power supply 15 of the camera 14 carrying the data control signal 31. The second mixer / splitter interface unit 52 is configured to receive the images data 33 mixed with the power supply 15 signal carried by one wire connection 19 and to split the images data 33 from the power supply 15 in order to provide the images data 33 to the microcontroller 58. Diagnostic data 29 of the light source component 30 are also split from the power supply 15 by the second mixer / splitter interface unit 52 such that the second mixer / splitter interface unit 52 is configured to provide the diagnostic data 29 to the microcontroller 58 of the ECU 16. To support the defined current-carrier communication between the ECU 16 and the camera, the coaxial cable 18 is connected at one extremity end to the ECU bidirectional signal port 50, and at the second extremity end to the camera bidirectional signal port 36.

Claims

1. Camera (14) for a motor vehicle (12) configured to communicate with an electronic control unit (ECU) (16) of the motor vehicle (12) comprising: an imager integrated circuit (22) configured to capture images from the motor vehicle (12) inside or outside environment; an illumination unit (28) in electrical communication with the imager integrated circuit (22), said illumination unit (28) comprising at least one light source component (30), the illumination unit (28) being configured to illuminate the inside / outside environment of the motor vehicle (12); a first mixer / splitter interface unit (34) in electrical communication with the imager integrated circuit (22); a camera bidirectional signal port (36) in electrical communication with the first mixer / splitter interface unit (34), said camera bidirectional signal port (36) being configured to be electrically connected with an external power supply (15) signal carrying data control (31) signal for the imager integrated circuit (22); said first mixer / splitter interface unit (34) being: - configured to split the data control (31) signal from the external power supply (15) signal and to provide the split data control (31) signal to the imager integrated circuit (22); - configured to provide images data (33) from the imager integrated circuit (22) mixed with the external power supply (15) signal to the camera bidirectional signal port (36); and - in electrical communication with the illumination unit (28); said first mixer / splitter interface unit (34) comprising: - a first voltage regulator (40) element to provide a first input voltage (23) from the split external power supply (15) signal to the imager integrated circuit (22), and - a second voltage regulator (42) element to provide a second input voltage (27), distinct from the first input voltage (23), from the split external power supply (15) signal to the illumination unit (28); wherein: the second voltage regulator element (42) comprises a constant current source (44) and an energy storage component (46) configured to be fed by the constant current source (44), said energy storage component (46) being configured to provide the second input voltage (27) to the illumination unit (28), the illumination unit (28) comprises a light source failure detection component configured to diagnose a short circuit and / or open circuit of the light source component (30) to get light source component (30) diagnostic data (29), said light source failure detection component being configured to provide the light source component (30) diagnostic data (29) to the imager integrated circuit (22), and said first mixer / splitter interface unit (34) being configured to provide the light source component (30) diagnostic data (29) mixed with the split external power supply (15) signal from the imager integrated circuit (22) to the camera bidirectional signal port (36).

2. Camera (14) according to the preceding claim characterized in that the first mixer / splitter interface unit (34) comprises: a first power over coaxial (PoC) filter element (48) in electrical communication with the camera bidirectional signal port (36), said first PoC filter element (48) being configured to split the data control (31) signal from the external power supply (15) signal and to provide the split data control (31) signal to the imager integrated circuit (22); and the first voltage regulator (40) element and the second voltage regulator (42) element which are both in electrical communication with the first PoC filter element (48).

3. Camera (14) according to claim 2 characterized in that the first PoC filter element (48) is further configured to mix the images data (33) with the external power supply (15) signal.

4. Camera (14) according to any one of the preceding claims characterized in that the illumination unit (28) comprises a light source driver (32) configured to control the illumination of the light source component (30).

5. Camera (14) according to claim 4 characterized in that the light source component is an infrared light source component (30).

6. Camera (14) according to any one of the claims 4 or 5 characterized in that the light source driver (32) is configured to provide a pulsed power signal to the light source component (30) such that the light source component (30) provides a pulsed illumination.

7. Camera (14) according to any one of the preceding claims characterized in that the imager integrated circuit (22) comprises a trigger pin in electrical communication with the illumination unit (28), the imager integrated circuit (22) being configured to trigger the illumination unit (28).

8. Vision system (10) for a motor vehicle (12) comprising the camera (14) of any one of the preceding claims, characterized in that the vision system (10) comprises an ECU (16) comprises an ECU bidirectional signal port (50), a second mixer / splitter interface unit (52) in electrical communication with the ECU bidirectional signal port (50), the external power supply (15) signal in electrical communication with the second mixer / splitter interface unit (52); a microcontroller (58) configured to provide the data control (31) signal to the second mixer / splitter interface unit (52); a coaxial cable (18) connected at one extremity end to the ECU bidirectional signal port (50), and at the second extremity end to the camera bidirectional signal port (36); the second mixer / splitter interface unit (52) being configured to provide the data control (31) signal mixed with the external power supply (15) signal to the ECU bidirectional signal port (50) such that the coaxial cable (18) is configured to electrically carrying the external power supply (15) signal mixed with the data control (31) signal; the second mixer / splitter interface unit (52) being configured to receive the images data (33) mixed with the external power supply (15) signal carried by the coaxial cable (18); and to split the images data (33) from the external power supply (15) in order to provide the images data (33) to the microcontroller (58).