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Nov 13, 2008, 04:29 AM
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Test flight #1 disaster


That didn't go so well. Throttle control isn't fast enough for rate damping to work at all. It's a complete, unflyable, quad disaster. The Suppo ESC's either don't have the response time or don't have enough throttle steps. That's what U get for being sucked into super low prices.

There's much less vibration in the quadrotor than the unirotor. With virtually no noise in the IMU, U don't have the drift anomalies that plagued us & U can probably use the accelerometer for some velocity estimation.

Not surprising that with all these advantages, Mikrocopter has solved most of the problems of autonomous VTOL in the last year & you'd now be hard pressed to bother with all we did when U can just buy a Mikrocopter. They're hauling in some serious dough with those parts.

Mikrocopter does it all on an 8 bit Atmel. It needs no Kalman filters, quaternions, ground based computing, crazy communication schemes, neural networks, or anything. Just straight gyro integration on all 3 axes, using integer math. Unfortunately the source code is in German & it depends on some crazy fixed point optimizations, so your hacking mileage may vary.

If the dynamic forces are low enough, a very high accelerometer blend & slow yaw rate can eliminate the need for a quaternion attitude estimate. High wind still might give U problems. Suspect quaternions & Kalmans will come to Mikrocopter soon enough, which is the biggest reason to still bother with VicaCopter: experimentation.

Switching to Mikrocopter now would take building their main board to the letter, building their ESC's & forgetting about touching the source code. That would be pretty heavy using protoboards & pretty expensive using their prefab boards.

So there's plenty of power to get the quad off the ground & it sounds just like a swarm of yellowjackets. Theoretically real yellowjackets R attracted to the sound of an enemy swarm of yellowjackets.

Using 9x6 props because that's all anyone had locally. Can't buy anything online until the typical crash needs R known or those Suppo ESC's are definitely disqualified.
Last edited by Jack Crossfire; Nov 13, 2008 at 04:37 AM.
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Nov 14, 2008, 12:29 AM
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Jack,

I have had better luck with the castle creations escs. They sent me some special firmware that allowed me to ramp up the slew rate on the throttle responce. Made for a flyable quad rotor with brushless motors. Still about 1 frame of lag. I improved that a bit by feeding the escs with 100 hz, instead of 50. The engineer at castle said they can handle about 100 hz. The easy solution is brushed motors and direct pwm.

Anyways, good luck.

Reed


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