Sharp ir on angles

[Bubbles]

i have recently made a CAD of a robot i want to build however a friend has pointed out to me that the robots' 'nose' is slightly lower than its 'back' and the sharp ir is mounted perpendicular to some mounts connecting two parallel pieces of metal (these braces also being perpendicular to the metal) this is causing my sharp ir to point at the ground at an angle which isn't 180 so i was wondering if this would mean it wouldn't work because as i understand it the sharp ir works by reflecting ir light, but if my sensor isn't parallel to the ground would the light simply bounce off in another direction and not back at the sensor because of this?

[Soeren]

Hi,

The beam is not like a laser pointer, but more like a narrow flash light - take a look at it with a cell phone camera, it should be able to "see" the beam in a darkened room.
So, it depends how much off you are.

Why point it to ground though, isn't it intended for obstacle detection?

[Admin]

It will work, because what is important is how you process the data in software.

If it points at the ground, that will be its maximum range, so just ignore anything detected at that maximum range.

[Bubbles]

so the sensor will be able to pick up the reflected light even though it meets the ground at ~45⁰?

[Admin]

Why wouldn't it?

[hazzer123]

As long as the surface that the IR sensor is hitting isn't mirrored, then it will be able to detect it, even at smaller angles than 45^o.

Its like if you point a flashlight at a wall at an angle, you can still see where the light hits the wall.

[Bubbles]

yes i get that analogy but i just thought that the light had to come back to the sensor for it to be able to 'see' it

[paulstreats]

it does.

provided that the surface isnt mirrored, the light scatters off in every direction including the one it came from. If it didnt and you shone a torch at the ground at 45 degrees then you wouldnt be able to see it since your eyes only pick up light that travels into them