Device for protecting an optical sensor and driving aid system comprising an optical sensor

1. A driving aid system for a motor vehicle, the driving aid system comprising:

an optical sensor,

a device for protecting the optical sensor, the device being fixed to the optical sensor and comprising:

a transparent optical element having a symmetry of revolution and mounted rotatably around an axis of rotation, the optical element being configured to be arranged upstream of the optical sensor so that the axis of rotation of the optical element coincides with the optical axis of the optical sensor;

an actuator coupled to the optical element for making the optical element rotate, to enable soiling to be removed by a centrifugal effect, and

an electronic control unit configured to activate the actuator in order to make the optical element rotate,

wherein the protection device comprises a capacitive proximity sensor connected to the electronic control unit and configured to detect the approach of another object in the proximity of the optical element, and to enable the electronic control unit to command the automatic stopping of the actuator, in order to halt the rotation of the optical element when another object approaches.

2. The driving aid system as claimed in claim 1 , wherein the actuator comprises an electric motor for driving the optical element.

3. The driving aid system as claimed in claim 2 , wherein said electric motor is configured to make the optical element rotate at a speed of between 7000 and 15000 r.p.m.

4. The driving aid system as claimed in claim 1 , wherein the actuator is coupled to the optical element by coupling means selected from the group consisting of: a belt, gearing, a resilient drive cylinder, and a roller.

5. The driving aid system as claimed in claim 1 , wherein the optical element has an outer surface having at least one of the properties selected from the group consisting of: hydrophobic, photocatalytic, superhydrophobic, oleophobic, hydrophilic, and superhydrophilic.

6. The driving aid system as claimed in claim 1 , wherein the optical element is formed by an outer lens of the objective lens of the optical sensor.

7. The driving aid system as claimed in claim 1 , wherein the optical element is separate from the objective lens of the optical sensor.

8. The driving aid system as claimed in claim 7 , wherein the optical element is connected to a fixing frame configured to receive the optical sensor.

9. The driving aid system as claimed in claim 1 , wherein the optical element is flat.

10. The driving aid system as claimed in claim 1 , wherein the optical element is convex.

11. The driving aid system as claimed in claim 1 , further comprising at least one nozzle for projecting a fluid onto the optical element.

12. The driving aid system as claimed in claim 1 , further comprising at least one bearing configured to enable the optical element rotate relative to the optical sensor.

13. The driving aid system as claimed in claim 1 , wherein the electronic control unit is configured to control the actuator so as to adapt the rotation speed of the optical element according to the speed of movement of the motor vehicle.

14. The driving aid system as claimed in claim 13 , wherein the actuator is configured to reduce the rotation speed of the optical element when the speed of the vehicle increases.

15. The driving aid system as claimed in claim 1 , wherein the electronic control unit is configured to actuate the projection of at least one fluid onto the optical element when the optical sensor detects the presence of soiling in its field of view.

16. The driving aid system as claimed in claim 15 , wherein the electronic control unit is configured to actuate the projection of two different fluids, such as cleaning liquid and compressed air, consecutively.