Method and device for increasing the robustness of a vehicle headlight having a cylindrical prism
A method is provided for increasing the robustness of a vehicle headlight comprising a cylindrical prism that can rotate about a rotary axis in a plurality of rotary positions and comprising a Hall effect sensor by means of the output signals of which the rotary position of the cylindrical prism can be determined. According to the method, a check is made as to whether a defect of the Hall effect sensor is present. In the event of a defect of the Hall effect sensor, a stop is temporarily provided and the rotary position of the prism is verified by being blocked at the provided stop.
1. A method for increasing the robustness of a vehicle headlight having a cylindrical prism that is rotatable about a rotary axis using a first drive, and a Hall sensor that generates output signals for determining a rotary position of the cylindrical prism, the method comprising:
performing a check to identify a defect of the Hall sensor,
in response to identifying a defect of the Hall sensor:
automatically moving the prism to a predefined stop position in which a movement of the prism is blocked by a physical stop, and
automatically moving the prism from the predefined stop position to another predefined position.
2. The method of claim 1 , wherein automatically moving the prism from the predefined stop position to another predefined position comprises rotating the prism to a predefined rotary position relative to the stop position.
3. The method of claim 1 , wherein moving the prism to the predefined stop position includes moving the prism with a second drive.
4. The method of claim 3 , wherein the second drive provides an axial displacement of the prism.
5. The method of claim 1 , wherein moving the cylindrical prism to the predefined stop position includes an axial displacement and a subsequent rotation of the cylindrical prism.
6. The method of claim 5 , wherein the predefined stop position for the prism is provided at an end stop of the second drive.
7. The method of claim 6 , wherein the subsequent rotation of the cylindrical prism comprises rotating the prism until a stop element provided on the cylindrical prism contacts a stop counter element of the end stop.
8. The method of claim 1 , wherein the check to identify the defect of the Hall sensor is performed in connection with a reference run.
9. An apparatus for increasing the robustness of a vehicle headlight, comprising:
a cylindrical prism rotatable about a rotary axis to a plurality of rotary positions using a first drive, and
a Hall sensor that generates output signals for determining a rotary position of the cylindrical prism,
a control unit configured to:
perform a check to identify a defect of the Hall sensor is present, and
in response to identifying a defect of the Hall sensor:
automatically move the prism to a predefined stop position in which a movement of the prism is blocked by a physical stop, and
automatically move the prism from the predefined stop position to another predefined position.
10. The apparatus of claim 9 , comprising a second drive configured to move the prism toward the predefined stop position.
11. The apparatus of claim 9 , wherein automatically moving the prism from the predefined stop position to another predefined position comprises rotating the prism to a predefined rotary position relative to the stop position.
12. The apparatus of claim 10 , wherein the second drive provides an axial displacement of the prism.
13. The apparatus of claim 9 ,
wherein a stop element is provided at the cylindrical prism and a stop counter element is provided at an end stop of the motor-vehicle headlight, and
wherein moving the cylindrical prism to the predefined stop position includes an axial displacement, and a subsequent rotation of the cylindrical prism until a stop element provided on the cylindrical prism contacts a stop counter element of the end stop.