Device for cleaning an optical sensor, and associated driver assistance system and cleaning method

1. A device for cleaning an optical sensor, comprising:

a nozzle for dispensing a cleaning liquid, wherein the cleaning liquid dispensing nozzle is a drip dispensing nozzle and is configured to deposit the cleaning liquid on the optical sensor in individual drops; and

a spray element configured to spray compressed airflow over the optical sensor, the spray element being an additional element relative to the nozzle,

wherein the device is equipped in a motor vehicle.

2. The device for cleaning an optical sensor according to claim 1 , further comprising a support for the cleaning liquid dispensing nozzle, said support being arranged in a fixed manner relative to the cleaning device.

3. The device for cleaning an optical sensor according to claim 2 , wherein the cleaning liquid dispensing nozzle is mounted movable in the support between:

a rest position in which the dispensing nozzle is configured to be retracted relative to an optical element of the optical sensor, and

an active position in which the dispensing nozzle is configured to be located above the optical element of the optical sensor so as to deposit said at least one drop of cleaning liquid on the optical element by gravity.

4. The device according to claim 1 , wherein the cleaning device comprises a metering pump configured to supply the dispensing nozzle with cleaning liquid in order to deposit a predefined volume of cleaning liquid on the optical sensor in drips.

5. The device for cleaning an optical sensor according to claim 1 , wherein the spray element is movable between:

a stowed position in which the spray element is configured to be positioned outside the field of view of the optical sensor, and

at least one cleaning position in which the spray element is configured to be positioned in front of the optical sensor.

6. The device for cleaning an optical sensor according to claim 5 , wherein the spray element comprises a nozzle for spraying a compressed air flow over the optical element when the spray element is in a cleaning position.

7. The device for cleaning an optical sensor according to claim 5 , wherein the cleaning device comprises a drive mechanism configured to move the spray element between the stowed position and said at least one cleaning position.

8. The device according to claim 5 , wherein the spray element is movable in rotation between the stowed position and said at least one cleaning position.

9. A driver assistance system comprising at least one cleaning device according to claim 1 ; at least one optical sensor; and at least one electronic control unit configured to control the cleaning device.

10. The driver assistance system according to claim 9 , wherein the electronic control unit is configured to control the drive mechanism, so to move the spray element between the stowed position and said at least one cleaning position.

11. The driver assistance system according to claim 9 , wherein the electronic control unit is configured to trigger the spraying of the compressed air flow over the optical element when the spray element is in a cleaning position and to stop said spraying of the compressed air flow when the spray element is in the stowed position.

12. The driver assistance system according to claim 11 , wherein the electronic control unit is configured to control the pressure at which the compressed air flow is sprayed over the optical element of the optical sensor.

13. The driver assistance system according to claim 1 , wherein the electronic control unit is configured to control the volume of cleaning liquid drawn by the metering pump and deposited in drips on the optical element of the optical sensor.