Roboto was built as a test platform for IR dection programming. Roboto does, however, have an bumper setup
that is capable of decting close to 100% of objects. Any ways as mentioned before Roboto is designed for IR dection. IR dection works by having the RCX send out an continous IR beam and then using a light sensor to detect its bounce back. However, ambient lighting has traditionaly been a problem, and the fact that not all objects will be detected is also a problem. Roboto's program attempts to solve these problems. First problem is the ambient lighting level, if its too bright then the IR dection will not work. To over come this problem, Roboto is programed to only use IR when the ambient lighting is level is low enough. This is checked before every message sent so as not to mess up. If the ambient lighting is to bright, then the bumpers will be used. However, the moment ambient lighting levels drop low enough, Roboto switches right back to IR dection. This results in an almost full proof setup. However, there is still the second problem which results in objects being missed, due to being off to the side or for what ever reason just not being detected. To overcome this problem, Roboto's bumpers are setup so that they still work while IR detection is being used. This way if IR misses an object, the bumpers should detect it. Overall Roboto was a great success, especially for only being my second IR detection bot. There are a couple problems though, one is that the IR detection at times is much to sensitive. I have had it detect objects a foot or more away, generally these objects are white and fairly reflective. Also, sometimes it seems to detect "ghost" objects, I think these result from reflections off the floor or from the IR beams bouncing off the bumpers it tended to work better if I took the bumpers off. However, the main problem is that certain light bulbs emit a light that seems to mess up the IR detection. It seems to be the newer "spiral" bulbs. The older "globe" bulbs don't cause any problems. Any ways, in most cases Robot works fine and has a smooth transition between IR dection and bumper dection. Also, Roboto backs up a random amount of time between 1s and 3s in all cases. And if the bumpers hit an object Robot turns the direction away from the obsticle for a random amount of time between 1s and 3s, however, if the IR detection detects the object then Robot will randomly decide to turn left or right. One more thing, the code is written in the RCX2.0 language.
I have allways wanted to build a robot that could actually see the world. However, with Legos the main three ways are using the vision command camera, IR detection or a homemade sensor. I decided to play around with IR. The result is Roboto, I had a lot of fun, and I'm planning on building a better version in the future. If you go here: Roboto you can view larger pictures of this invention, just click on the sliding pictures on the page.