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Proximity Sensor selection questions for Propeller — Parallax Forums

Proximity Sensor selection questions for Propeller

TheGrueTheGrue Posts: 114
edited 2009-04-09 07:05 in Accessories
I am conceptualizing a design for a new robot based on the Propeller and the Motor Mount & Wheel Kit. The robot will be both an indoor and an outdoor bot that travels between buildings by navigating its way through a parking lot and on sidewalks. I am looking for ideas for sensors to detect objects and obstacles that could trap the Bot. I do not want to overload the bot with sensors but I have specific desires and a specific obstacle course in mind. I am not looking for help on navigation from point A to point B right now.

The bot will have to avoid driving off of raised sidewalks and curbs, follow the edge of a curb to a wheelchair ramp, cross a parking lot that may have cars or other obstacles, follow another curb and up another wheelchair ramp to the next building entrance. I was also thinking of having sensors in front of each wheel to avoid things like potholes or one of the many 90 degree T's in sidewalks that the wheels may drop into and get stuck. Also I thought that they could be used to detect if it is driving into rising water during bad weather. I am not needing water proof sensors, just water resistant and inexpensive if they get ruined by wet weather.

I have heard that PING))) and other ultrasonic sensors are not good to detect cliffs or stairs if pointed at angles like 45 degrees. I do not know the top speed of the Motor Mount Kit that Parallax offers but I would want to stop the bot before it went off a curb. I am intrigued by the LV-MaxSonar-WR1 for being long distance and weather resistant. Also it would be good to take indoor readings if I had one facing all four directions. It could be used to identify corridors and for indoor mapping. The down side to this sensor is that 0-12 inches is read as 12 inches. The up side is that it runs on 3-5V and has several types of outputs that would easily interface with the Propeller. I also see that the Sharp line of IR sensors are popular and I purchased two for testing (GP2D12 and GP2D120). I set them near each other to scope their outputs and found out that they interfered with each other when pointed in the same direction or looking at the same object. The up side is that they are cheap if they get toasted by the weather. The down side is that each runs on 5V and needs A/D conversion to get useful distance readings.

I am done rambling now and wish to hear lots of ideas...LOL

Comments

  • SRLMSRLM Posts: 5,045
    edited 2009-04-09 06:41
    Bumpers are always a good start. Simple implementation and virtually fool proof.
  • TheGrueTheGrue Posts: 114
    edited 2009-04-09 07:05
    True... But I think the boss would not take kindly to multiple scuff marks on the drywall of his new office buildings or his BMW...LOL
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