Segway and input filtering

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[Kerry] is building a segway type vehicle for a senior project. Though it doesn’t appear to be done yet, there is some good work finished. As with any balancing bot, it relies heavily on input from a gyroscope, and at least in this case, an accelerometer. That data can be very messy. The sensitivity of the sensor means that people often end up with vibrating or drifting in their projects. [Kerry] has put some work into finding a method of smoothing that results in fast, accurate, but smooth reaction. You can see a video of some comparisons between methods after the break.

25 thoughts on “Segway and input filtering

  1. Someone from the US please download the video and reupload it to youtube (with apropriate credits) so that we can get around the nazi restrictions.

  2. Looks like there’s not really much in it. The left and right ones just look like low-pass filtered versions of the kalman output.

    Also, I hate it when people drag 30 second videos into 3 minutes so they can play their favourite music over it.

  3. Just so you guys know, that is not my video. I will be sure to make one of these as soon as I recieve my sensors. I posted this as an example for filtering. Thanks for everything though!

  4. Because the song is commercial, youtube has detected it, and puts a little “buy in itunes” ad on the youtube page. This doesn’t appear in embedding, so it doesn’t make a difference here, but the ad deal isn’t available in every country – I guess they have to make deals with each country’s respective royalty collection boards.

    If the video maker had simply not chosen that song, this wouldn’t be an issue…

  5. the video means absolutely nothing without the model and noise parameters used.

    also, what is the person trying to do? estimate the orientation of the board? or smoothen the orientation measurement?

    if the former, they would need ground truth to assess how well each filter does. Ground truch is hard to obtain in this case, though, so it may be better to implement the controller for the segway and simulate it with each filter to compare them.

    if the person just wants to smoothen the orientations, a simple low pass with the right parameters would do just fine — at a smaller computational cost.

  6. Video works for me on mainland EU, I see the adlink for itunes but you’ll never see itunes on my systems anyway so that’s wasted effort.

  7. A completely useless video that explains and demonstrates nothing.

    I wonder when we will get a good demo of it because wild changes like that is worthless. the only VALUABLE 6 seconds of the video are in the middle where you see the input going wonky and the filters stopping it, everything else was 100% useless.

  8. Will someone with actual knowledge of nonlinear feedback system design stop all this nonsense and just publish a working mathematical model already! This isn’t the kind of thing you can get working well by hacking with it. You need the proper theoretical foundation.

  9. As I had said before, this is my blog and I have yet to even purchase a Gyro or Accelerometer (Actually buying them tonight). I will be sure to post all of my models, software and non-musical videos when I get the chance.

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