When I drive home, I open my garage door from my truck. I cannot see the garage door until I turn into my driveway. I want to know the range of my opener. How close can I get to knowing the farthest distance at which it will open in one drive down the road towards my house?
Assumptions for simplicity:
The door takes exactly 10 seconds to open or close fully. (And it closes at a uniform rate).
The road leading past the house is straight.
The distance from the road to the garage is negligibile.
I can click the opener as many times as I want.
If I click the opener while the door is closing, it begins opening and vice versa.
I can discern differences in the height of the door as small as 6 inches, meaning I can tell the difference between 1/2 and 1/3rd, but not between 1/5th and 1/6th. (These numbers are largely arbitrary – basically, I want a practical solution that doesn't involve measuring the final height of the door with lasers and levels)
Finally, I know how far away I am at any time. I know the opener doesn't work at 150 feet and does work at 50 feet. [Edit credit: joriki]
This is my first time posting here, so please let me know if there are any additional details I ought to add. Thanks!
Best Answer
You could drive at such a speed that you cover the first 10 feet in 5 seconds, the second 10 feet in 2.5 seconds, the third 10 feet in 1.25 seconds, etc. At each 10 foot mark press the remote. When you get to the garage, the height of the door will tell you when the remote first worked. You'll have your answer to withing 5 feet.
(This may require lasers, after all. And you might burn up in the atmosphere just as you arrive. But this is math, so practical considerations no matter.)