Automatic controller for powered retractable sun visor
A system and method for controlling a vehicle sun visor that uses commonly existing onboard sensors and systems to provide all necessary inputs. The method uses GPS and solar almanac data to determine the location of the sun relative to the vehicle, driver side view mirror angle data to determine the position of the driver's eyes within the vehicle, and an existing outside light metering device to determine whether the sun is actually shining on the vehicle, and uses this information to calculate the optimum position of the sun visor. If a forward-looking camera is available on the vehicle, camera images can be used to improve the estimate of the sun position relative to the vehicle.
1. A method for automatically controlling a vehicle sun blocker, said method comprising:
determining the position of the sun relative to the vehicle, including using solar position information from a Global Positioning System receiver and a solar almanac database and solar position information from a forward-looking camera onboard the vehicle in a Kalman filtering routine to determine the position of the sun relative to the vehicle;
estimating the position of eyes of a vehicle driver, including using an angular position of a driver side view mirror; and
deploying the sun blocker in a position between the sun and the driver's eyes.
2. The method according to claim 1 further comprising measuring the intensity of sun light on the vehicle, determining whether the vehicle is in a sunny location or a shaded location, and deploying the sun blocker only if the vehicle is in a sunny location.
3. The method according to claim 1 wherein estimating the position of the vehicle driver's eyes includes using images from a driver-viewing camera.
4. The method according to claim 1 further comprising allowing the vehicle driver to manually override the position of the sun blocker.
5. The method according the claim 1 further comprising using information from a previous driver imposed sun blocker position to update the position of the sun blocker.
6. A system for automatically controlling a sun blocker for a vehicle, said system comprising:
a solar position estimator which uses input from a Global Positioning System receiver and a solar almanac database and input from a forward-looking camera in a Kalman filtering algorithm for estimating the position of the sun relative to the vehicle;
a driver's eye position estimator which uses input from a driver side view mirror position encoder for estimating the position of eyes of a driver within the vehicle;
a shade detection module for determining whether the vehicle is currently in a sunny location or a shaded location;
a controller for determining a location to position the sun blocker in response to inputs from the solar position estimator, the driver's eye position estimator, and the shade detection module; and
an actuator for positioning the sun blocker as determined by the controller.
7. The system according to claim 6 further comprising a learning module, said learning module using information about a driver imposed sun blocker position to revise the location to position the sun blocker as determined by the controller.
8. The system according to claim 6 wherein the sun blocker is a mechanical sun visor.
9. The system according to claim 6 wherein the sun blocker is an electro-chromic glass shading system.
10. A system for automatically controlling a vehicle sun blocker, said system comprising:
a solar position estimator which uses Global Positioning System data and a solar almanac database to determine the position of the sun relative to the vehicle;
a driver's eye position estimator which uses data from a driver side view mirror position encoder to estimate the location of a driver's eyes;
a shade detection module which uses solar irradiation intensity data to determine whether the vehicle is in a sunny location or a shaded location;
a controller for determining a location to position the sun blocker in response to inputs from the solar position estimator, the driver's eye position estimator, and the shade detection module;
an actuator for positioning the sun blocker as determined by the controller; and
a learning module, said learning module using information about a driver imposed sun blocker position to revise the location to position the sun blocker as determined by the controller.
11. The system according to claim 10 wherein the solar position estimator uses additional input from a forward-looking camera and uses the Global Positioning System data, the solar almanac database, and the input from a forward-looking camera in a Kalman filtering algorithm to determine the solar position.