Looking at some cheap digital sensors yesterday. I am amazed at how cheap the things that were just a few decades ago ten of thousands of pounds. At BAE I was part of a project that was worth millions, yet now that same functionality is embedded in a little unit costing $50, alongside the built-in functions that the rest of the nav computer had!
So, with this part we can tell the orientation of a vehicle, using a 3 axis gyro. Using a real-time clock and an almanac, we can correlate the position of the sun to the position and orientation of the vehicle.
So far, so ‘easy’ – this would have been beyond even aerospace ability 30 years ago, and insanely expensive just a decade ago.
The huge rotating wheels used for a traditional gyro would have hurt the MPG in a small car! Today, the new MicroElectronic Mechanical Systems, or MEMS, are cheaper that the raw materials that made up the precision flywheels.
Anyway, point is, once you know where the sun is, you can move something or block something easily. So either add LCD to the windscreen and blank out where the sun is, or, more easily but less cool, move a small metal foil disc into the way of the sun.
Of course, another way would be a video camera pointing at the drivers face, keeping their eyes shaded using realtime feedback from a forward facing camera that would also ‘see’ the sun.