Reflective Spider Feet?

[Plepel]

Hello all! This is my first post, so bear with me.

My team was wondering, how reflective are the feet at the end of the spider legs? We had the cool idea that we could mount the camera and an LED to the end of out arm, and then have is search for a reflection of the LED, thus finding where the actual foot it. Would this be possible? The schematics say that they are made out of "bright aluminum", which would be reflective enough, but our members who went to the local kickoff said that the metal was a dull gray. Does anyone know?

Hmm.. the led might be illegal since it could effect other bots. But you could use the lights that they provide for your robot, the one that is either read or blue... Then again your bot might get messed up with the other bot's lights.

As for the reflectiveness of the spider leg, I am not sure.

[mtaman02]

Usually at local kickoffs (if this is your first local kickoff that you attended) they use the cheaper costing parts to make up a partial segment of the field since FIRST has not built enough fields for each local kickoff event. Not to mention not all events have the space to have a nice looking Field Layout. Which would explain why the metal was dull. The Metal will probably have a clean aluminum color to it for at least a few rounds before being scratched up by the robots. Why don't you try using the camera supplied in the kit and search for the Green Lights. Instead of looking for metal, since a large portion of the field is metal (Barriers, Walls & Goals - They mostly have the same color as well).

[Gdeaver]

Yes, that would work. The choice of frequency is the key.

[Al Skierkiewicz]

Originally Posted by Plepel

Hello all! This is my first post, so bear with me.

My team was wondering, how reflective are the feet at the end of the spider legs? We had the cool idea that we could mount the camera and an LED to the end of out arm, and then have is search for a reflection of the LED, thus finding where the actual foot it. Would this be possible? The schematics say that they are made out of "bright aluminum", which would be reflective enough, but our members who went to the local kickoff said that the metal was a dull gray. Does anyone know?

Plepel,
The bottom of the goal will be aluminum diamond plate. It is fairly reflective but will become scratched as robots interact and contact the surface. It is unlikely that your source LED will be considered to interact with other robots unless it is the same color as the goal lights. In any case, teams looking for the goal lighting should be looking up and not down at the floor. You will be subject to inspection on this component at each event. I hope you can make it work, I would like to see it.

[SuperBK]

What about using a sonar sensor to detect the plate on the rack? Would that be legal?
Brian

[Brandon Holley]

i was at kickoff in manchester, i saw the field, and the spider legs are exactly what they say they are, aluminum diamond plate. I would call it "shiny"...but basically if you pick up any piece of alumnium diamond plate and buff it with some kind of cotton you will get what the spider foot looks like.

[dtengineering]

We have done some experiments with IR sensors on diamond plate... perhaps a simple reflective sensor may not have the same problems, but with the Sharp IR rangefinders we have found them to have serious challenges when the diamond plate is at anything other than exactly 90 degrees... horizontally and vertically... to the sensor. This is, perhaps, as one might expect, but it was worth trying anyways. Diffuse (non-relfective) objects work great... but the shinyness of the diamond plate is a real pain in our application.

We are going to try some sonar rangefinders, and do have a few applications in mind for the IR, but make sure you test your device on aluminum diamond plate at the earliest opportunity.

Good luck,

Jason

[petek]

A couple of questions which pop in my head about the do-ablity of your idea:
How far away from the foot do you plan to be? (The farther away you get, the weaker any reflection of your light would be and the more interference you'd get)
Do you hope to detect the foot from an angle, or just perpendicular to it? (The more on-axis you are the better your chances will be)
Don't forget that there is a diamond plate skirt all the way around the bottom of the rack which might create a lot of reflection interference if you're looking at the lower spider feet, but it might also be a bigger target...

[AdamHeard]

Originally Posted by dtengineering

We have done some experiments with IR sensors on diamond plate... perhaps a simple reflective sensor may not have the same problems, but with the Sharp IR rangefinders we have found them to have serious challenges when the diamond plate is at anything other than exactly 90 degrees... horizontally and vertically... to the sensor. This is, perhaps, as one might expect, but it was worth trying anyways. Diffuse (non-relfective) objects work great... but the shinyness of the diamond plate is a real pain in our application.

We are going to try some sonar rangefinders, and do have a few applications in mind for the IR, but make sure you test your device on aluminum diamond plate at the earliest opportunity.

Good luck,

Jason

I suggest trying to find some VEX ultrasonics. They are cheap, already in a durable package and prewired (just need a female to female PWM cable, or the standard Y-splitters work too).

[JamesBrown]

Originally Posted by AdamHeard

I suggest trying to find some VEX ultrasonics. They are cheap, already in a durable package and prewired (just need a female to female PWM cable, or the standard Y-splitters work too).

The Vex Ultra sonic sensors definitly work, I have only tested it from about 2 feet to about 2 inches but they don't have much trouble with the diamond plate.

[AV_guy007]

one thing to note is the lights at regionals are very bright. they use stage lights to illuminate the field and the reflection from the lights may cause issues when trying to see the reflection of your LED