GPS + Accelerometer + Kalman Filter --> radio controlled aircraft pose

<goyiarteva> 21 years ago

I want to build a pose (position and attitude) measurement/estimation unit for my radio controlled aircraft by using * A PIC or an AVR microcontroller or an Ipaq PDA * A GPS receiver with serial data output * 3 x ADXL ??? accelerometer (3 axis, X,Y,Z) * Kalman filter * Expert advice from robotics gurus on the news group

- Reading the GPS data from the seial port is not difficult

- Digitizing ADXL ??? accelerometer outputs from 3 sensor is not difficult either

- Using Kalman Filter to fuse GPS and ADXL outputs is NOT easy for me. (I'm trying to learn Kalman Filter)

- Can some one help me how to combine/fuse four input data; (GPS + accelerations on X,Y,Z axis) to estimate accuratelly the pose of the aircraft ?

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Shawn Brown 21 years ago

Here's a site with some info and links to tutorials. I'd like to learn how to apply them as well for the same application.

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Mitch Berkson 21 years ago

See:

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and

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Mitch

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Steve 21 years ago

You can get aircraft position with all that but you're going to need sensors detecting the rotations in each axis to get pitch/roll/yaw attitude. Think solid state gyros.

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<goyiarteva> 21 years ago

do you think 3 accelerometers are not enough for that?

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dave.harper 21 years ago

attitude.

Actually, I don't think he'd be able to get a good estimation of attitude based on those sensors. Position (alt, latitude, long) sure... but for attitude you'd need either low-drift gyros, a horizon sensor, or something similar.

Dave

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Steve 21 years ago

You need to detect the rotation of the vehicle to get attitude. Accels detect the translation of the vehicle.

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dave.harper 21 years ago

Accels

Yeah, or use a reference (or multiple references), like a magnetometer, a horizon sensor, or a sun sensor.

Dave

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Chris S. 21 years ago

No. Visit that Rotomotion link Mitch posted. You need to measure linear

*and* rotationally acceleration in 3D space.

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dave.harper 21 years ago

You can get attitude from gyros alone, although not full position. Regardless, (without a big budget) I don't think you'd be able to get prolonged, accurate attitude information unless you had a really fast processor and very low-drift gyros.

Dave

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