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Unread 22-06-2013, 08:28
Gdeaver Gdeaver is offline
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Re: Real velocity Measurement Sensor

A camera and 2d optic flow algorithms will give you x and y. A optic mouse is an example of a sensor that uses optic flow to give this. The problem with mice sensors are the optics and the maximum velocity they can work at. Recently, some drone hobbyist have taken a good camera and interfaced it to a Cortex M4 Arm microcontroller. They also added a ST Micro gyro. There is not allot of feed back as to ground based applications and I believe it is best at greater than 12" off the floor. Different optics and some Lighting experimentation may yield a very good solution. Our team has been looking at auton navigation this summer. OpenCV has optic flow algorithms that could be used if these solutions are not fast and accurate enough. Goggle optic flow and check Wikipedia. A gyro and an accelerometer like the Invensense MPU-6050 will give a very good tilt compensated Yaw.
The other possibility is to use astral navigation. Every event has lights in the ceiling that are fixed like stars. Point a camera up at the ceiling. Using some filters a pixel matrix of dark and light (0 and 1) can be produced. Then run 2 d optic flow on that matrix. The lights are far enough away that some triangulation can also be done. Every event has different lights and it would have to be calibrated at each event. This stuff is hard else every one would be doing it.
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Unread 22-06-2013, 14:26
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Re: Real velocity Measurement Sensor

Velocity relative to what? Whatever your answer, that (thing) needs to be part of the solution.

Even the carpet can slip if you push hard enough.

If a contact solution isn't desired, then contactless means optical of some type, or maybe ultrasonic.

Astral navigation would work, but what a pain to do. It would have to adapt to the current lighting setup no matter where. I have a "Mint" floor cleaner, it uses something like that, but the pattern is fixed. (It sends an IR pattern to the ceiling, which the Mint uses for navigation). This is still optical though...
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Unread 24-06-2013, 12:03
purduephotog purduephotog is offline
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Re: Real velocity Measurement Sensor

Quote:
Originally Posted by Gdeaver View Post
A camera and 2d optic flow algorithms will give you x and y. A optic mouse is an example of a sensor that uses optic flow to give this. The problem with mice sensors are the optics and the maximum velocity they can work at. Recently, some drone hobbyist have taken a good camera and interfaced it to a Cortex M4 Arm microcontroller. They also added a ST Micro gyro. There is not allot of feed back as to ground based applications and I believe it is best at greater than 12" off the floor. Different optics and some Lighting experimentation may yield a very good solution. Our team has been looking at auton navigation this summer. OpenCV has optic flow algorithms that could be used if these solutions are not fast and accurate enough. Goggle optic flow and check Wikipedia. A gyro and an accelerometer like the Invensense MPU-6050 will give a very good tilt compensated Yaw.
The other possibility is to use astral navigation. Every event has lights in the ceiling that are fixed like stars. Point a camera up at the ceiling. Using some filters a pixel matrix of dark and light (0 and 1) can be produced. Then run 2 d optic flow on that matrix. The lights are far enough away that some triangulation can also be done. Every event has different lights and it would have to be calibrated at each event. This stuff is hard else every one would be doing it.
I'm dumbfounded.

I've worked with space based navigation and lever arms and planes and Kalman filters. .. and I have never, ever once considered looking up to navigate.

*bows*
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