System for self-aligning vehicle headlamps

• US 5,633,710 A
• Filed: 10/04/1995
• Issued: 05/27/1997
• Est. Priority Date: 10/04/1995
• Status: Expired due to Fees

• Current Assignee: EGS, Inc.
• Original Assignee: EGS, Inc.
• Inventors: Scherrer, Michael F., Kumra, Mohinder
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US08/539,053
• Time in Patent Office: 601 Days
• Field of Search: 356/139.06, 356/139.08, 356/121, 362/66, 362/71, 315/82, 315/83
• US Class Current: 356/139.08
• CPC Class Codes: B60Q 1/10 due to vehicle inclination, e.g. due to load distribution
• CPC Class Codes: B60Q 2300/132 Pitch
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01M 11/068 with part of the measurements done from inside the vehicle

Abstract

A system for self-aligning a headlamp of a vehicle, the system comprises at least one actuator which modifies an alignment of the headlamp in response to a control signal. An infrared light source is mounted to the headlamp to emit an infrared light beam toward a ground surface. An optical sensor system is oriented to sense a reflection of the infrared light beam from the ground surface. The optical sensor system has a plurality of optical sensors to sense a plurality of infrared light intensities from the reflection. A control circuit is operatively responsive to the optical sensor system to form the control signal for the at least one actuator. The control signal acts to modify the alignment of the headlamp so that the infrared light intensities satisfy at least one predetermined condition consistent with a desired alignment of the headlamp to thereby automatically align the headlamp to the desired alignment.

Claims

1. A system for self-aligning a headlamp of a vehicle, the system comprising:

at least one actuator which modifies an alignment of the headlamp in response to a control signal;

an infrared light source mounted to the headlamp to emit an infrared light beam toward a ground surface;

an optical sensor system oriented to sense a reflection of the infrared light beam from the ground surface, the optical sensor system having a plurality of optical sensors to sense a plurality of infrared light intensities from the reflection; and

a control circuit operatively responsive to the optical sensor system to form the control signal for the at least one actuator, wherein the control signal acts to modify the alignment of the headlamp so that the infrared light intensities satisfy at least one predetermined condition consistent with a desired alignment of the headlamp to thereby automatically align the headlamp to the desired alignment.

2. The system of claim 1 wherein the infrared light source includes an infrared light emitting diode mounted on a surface of a reflector of the headlamp, the infrared light emitting diode emitting the infrared light beam initially toward a top portion of the reflector, wherein the reflector redirects the infrared light beam down toward the ground surface.

3. The system of claim 1 wherein the infrared light source is modulated in accordance with a vehicle-specific signature to avoid interference from an external source of infrared radiation.

4. The system of claim 1 wherein the at least one predetermined condition includes a first condition based upon a comparison of infrared light intensities sensed by two of the plurality of optical sensors.

5. The system of claim 1 wherein the optical sensors includes a first optical sensor, a second optical sensor, a third optical sensor, and a fourth optical sensor spaced around a fifth optical sensor.

6. The system of claim 5 wherein the at least one predetermined condition includes a condition that the infrared light intensity sensed by the first optical sensor be substantially equal to the infrared light intensity sensed by the third optical sensor.

7. The system of claim 5 wherein the at least one predetermined condition includes a condition that the infrared light intensity sensed by the second optical sensor be less than or equal to the infrared light intensity sensed by the fourth optical sensor.

8. The system of claim 5 wherein the at least one predetermined condition includes a condition that the infrared light intensity sensed by the fifth optical sensor be greater than the infrared light intensities sensed by the first optical sensor, the second optical sensor, the third optical sensor, and the fourth optical sensor.

9. The system of claim 5 wherein the at least one predetermined condition includes a first condition that the infrared light intensity sensed by the first optical sensor be substantially equal to the infrared light intensity sensed by the third optical sensor, a second condition that the infrared light intensity sensed by the second optical sensor be less than or equal to the infrared light intensity sensed by the fourth optical sensor, and a third condition that the infrared light intensity sensed by the fifth optical sensor be greater than the infrared light intensities sensed by the first optical sensor, the second optical sensor, the third optical sensor, and the fourth optical sensor.

10. The system of claim 1 wherein the at least one actuator includes a first control motor which modifies a pitch of the headlamp and a second control motor which modifies a heading of the headlamp.

11. The system of claim 1 further comprising:

a second infrared light source located within the vehicle; and

a second actuator operatively responsive to the control circuit to modify an orientation of the optical sensor system;

wherein the control circuit commands the second actuator to perform the steps of rotating the optical sensor system toward the second infrared light source by a predetermined rotation, modifying the orientation of the optical sensor system so that the infrared light intensities satisfy at least one predetermined condition consistent with a desired orientation of the optical sensor system, and rotating the optical sensor system back to an operating orientation based on the predetermined rotation.

12. The system of claim 11 wherein the optical sensors includes a first optical sensor, a second optical sensor, a third optical sensor, and a fourth optical sensor spaced around a fifth optical sensor, and wherein the at least one predetermined condition consistent with the desired orientation includes a condition that the infrared light intensity sensed by the fifth optical sensor be greater than the infrared light intensities sensed by the first optical sensor, the second optical sensor, the third optical sensor, and the fourth optical sensor.

13. A system for self-aligning a headlamp of a vehicle, the system comprising:

at least one control motor which modifies an alignment of the headlamp in response to a control signal;

an infrared light emitting diode mounted on a surface of a reflector of the headlamp, the infrared light emitting diode emitting an infrared light beam toward a top portion of the reflector for redirection down toward a ground surface, the infrared light beam being modulated in accordance with a vehicle-specific signature;

an optical sensor system having a plurality of optical sensors oriented to sense a plurality of infrared light intensities from a reflection of the infrared light beam from the ground surface, the plurality of optical sensors including a first optical sensor, a second optical sensor, a third optical sensor, and a fourth optical sensor equally spaced around a fifth optical sensor; and

a control circuit operatively responsive to the optical sensor system to form the control signal for the at least one control motor, wherein the control signal acts to modify the alignment of the headlamp so that the infrared light intensities satisfy a plurality of predetermined conditions consistent with a desired alignment of the headlamp, the plurality of predetermined conditions including a first condition that the light intensity sensed by the first optical sensor be substantially equal to the light intensity sensed by the third optical sensor, a second condition that the light intensity sensed by the second optical sensor be less than or equal to the light intensity sensed by the fourth optical sensor, and a third condition that the light intensity sensed by the fifth optical sensor be greater than the light intensities sensed by the first optical sensor, the second optical sensor, the third optical sensor, and the fourth optical sensor.

14. A system for self-aligning a right headlamp and a left headlamp of a vehicle, the system comprising:

a first control motor which modifies a pitch of the right headlamp in response to a first control signal;

a second control motor which modifies a heading of the right headlamp in response to a second control signal;

a third control motor which modifies a pitch of the left headlamp in response to a third control signal;

a fourth control motor which modifies a heading of the left headlamp in response to a fourth control signal;

a first infrared light source mounted to the right headlamp to emit a first infrared light beam toward a ground surface;

a second infrared light source mounted to the left headlamp to emit a second infrared light beam toward the ground surface, wherein the first infrared light beam and the second infrared light beam intersect the ground surface at substantially the same location for a desired alignment of the right headlamp and the left headlamp;

a first optical sensor system oriented to sense a reflection of the first infrared light beam from the ground surface, the optical sensor system having a first plurality of optical sensors to sense a first plurality of infrared light intensities from the reflection;

a second optical sensor system oriented to sense a reflection of the first infrared light beam from the ground surface, the optical sensor system having a second plurality of optical sensors to sense a second plurality of infrared light intensities from the reflection; and

a control circuit operatively responsive to the first and second optical sensor systems to form the first, second, third, and fourth control signals for the first, second, third, and fourth control motors, wherein the control signals acts to modify the alignment of the headlamps so that the infrared light intensities satisfy at least one predetermined condition consistent with the desired alignment of the headlamp to thereby automatically align the headlamps to the desired alignment.

15. The system of claim 14 wherein the first plurality and the second plurality of optical sensors each includes a first optical sensor, a second optical sensor, a third optical sensor, and a fourth optical sensor spaced around a fifth optical sensor.

16. The system of claim 14 wherein the first optical sensor system is mounted to one side of the vehicle, and the second optical sensor system is mounted to another side of the vehicle.

17. The system of claim 14 wherein at least one of the first, second, third, and fourth control signals is dependent upon a difference in infrared light intensity between one of the first plurality of optical sensors and one of the second plurality of optical sensors.