Visual Odometry to Estimate Position without GPS??

Question

Hi all,Just wondering if anyone knows of alternatives to getting positioninformation without GPS? I have an indoor helicopter which I haveautonomously hovering, but it starts to drift because of drafts or theIMU is not perfectly positioned (i.e. it's not exactly parallel to theground). Double integrating accelerometer data is prone to erroraccumulation so that's not an option.The only thing I can think of doing (excluding indoor GPS) is to pointa camera down towards the ground and use some sort of visual odometryalgorithm. If anyone else has any other ideas, I'd appreciate it.If someone thinks visual odometry will work, I'd appreciate any adviceon the fastest way to successful implementation.Thanks in advance!-weg22

Sir Charles W. Shults III · Accepted Answer

You might have a good idea there. Look at the optical mouse on any computer. It uses a small cell count CCD camera chip. They typically have something like an 18x18 cell array. That sounds wimpy but look at this project link:

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I have a feeling that you could do something significant with this.

Cheers!

Sir Charles W. Shults III, K.B.B. Xenotech Research

321-206-1840

Pascal A. Brisset · Answer

Or you can buy a miniaturized commercial version here:

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was impressed that this idea went to market so quickly. It would be nice if we could modify these devices to do full-featured odometry (e.g. combine them with range sensors).

zwsdotcom · Answer

Directional ultrasonic rangefinders, with different frequencies?

Pogo · Answer

You might also find some interesting ideas, if nothing else, by Googling = on "localization robotics". I stumbled upon "localization" on the = Evolution Robotics website, and this group filled me in on what it = meant. Sounds like the same sorta thing you need. Here's the Evolution = link, just to get started: =

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Good luck ! JCDeen

Vilas Kumar Chitrakaran · Answer

If the indoor area you are flying in is rather small, you could place a planar visual target (with multiple easily detectable features) on the floor, and use something techniques like homography to obtain vehicle position and orientation. You might even be able to autonomously land a helicopter using this approach!.

Try the following papers for a good description. You don't have to implement the control approach presented in these papers if you don't need to. You can definitely do the visual position estimation part:

See PDF of my paper from:

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A good paper on helicopter control using ground visual targets: O. Shakernia, Y. Ma, T. J. Koo, and S. Sastry, ?Landing an Unmanned Air Vehicle: Vision Based Motion Estimation and Nonlinear Control,? Asian Journal of Control, Vol. 1, No. 3, pp. 128?145, 1999

Vilas

Fred* · Answer

"Sir Charles W. Shults III"  a écrit dans le message de news: kFP1h.2$    ...Thanks for this interesting link..Fred

Visual Odometry to Estimate Position without GPS??

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