Nuisance V1 - Next Steps

  • Tune - I need to tune the turn and speed algorithms to get rid of the oscillations caused by changing location or direction faster than the map updates can keep up.
    • By tuning several variables, I was able to get a nice smooth reaction to objects. The relevent variables were:
      • Max turn rate - slowing this down just a little kept it from oscillating
      • Max speed - by slowing the speed down just a little, I kept it from overrunning the sensor data. When it goes too fast, it will hit something before the sensors can register it on the map and the map interpretation functions can react to it. This is especially true of the IR rangefinders since they have a max useful distance of about 2 feet.
      • Scan rate and degrees per scan of the various sensors - by having few steps but doing them more quickly, I was able to get more timely data into the map. I had to be careful not to try to turn the sensor aiming servos faster than they are physically capable. If that happens, then the assume aim is not the same as the actual aim and the accurracy deteriorates.
  • Detect stairs - I have yet to find a good way to determine when it is about to plummet down the stairs or any other abrupt edge like that
  • Whisker switches - I plan to attach whisker switches in front and above the bumper to try to detect low and high objects that the sensors miss.
    • Adding these switches helped a lot for finding things that are soft or down low. The only problem is that they tend to get tangled in soft items like dog beds and blankets. When this happens, the robot jerks all over and can damage the switches.
  • 4WD - I am going to experiment with adding 2 more drive wheels and removing the Omniwheel. I suspect this will improve the ability to run over small things and deal with rough or soft terrain. But it will also likely hinder the turning performance on some surfaces where slip will not happen easily.
    • 4WD made a huge difference in the ability to deal with obsticles and soft terrain.
    • Turning performance did suffer some, but I was able to compensate by increasing the max turn rate in the tuning perameters.
  • Camera - Long term plans are to add a camera and experiment with computer vision

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