Hi all,
MatrixPilot quad_testing code begins to be funny to fly :)
In the video you can see a flight with the code at r1158. It is very stable and reliable. Controls are very smooth.
The quadrocopter is an Arducopter frame equipped with UavDevBoard4. No GPS, no other sensors are used at the moment. The only available mode is Fly By Wire for now.
Many thanks to Bill Premerlani and his fast implementing of his great research and development work on this subject.
Performances are growing up very quickly.
Best regards,
Ric
Comments
Hi Roy,
You are correct on your description of the controls we have right now. For roll and pitch, we are using the roll and pitch elements of the Z row of the direction cosine matrix. However, I am presently in the process of changing that, to use a more general approach. The pilot input will control a virtual quad inside the controller, and PID(DD) (meaning P, I, D, and second derivative) controls will drive the real quad to match the virtual quad. This will provide a framework to do pretty much anything anyone might want to do, including aerobatics.
There is a particularly elegant way to control the orientation of the real quad to match the orientation of the virtual quad, using direction cosine matrices. The orientations of both quads are represented by direction cosine matrices. The input to the PID controller is computed by multiplying the matrix representing the virtual quad by the transpose of the matrix representing the actual quad.
As to what modes we eventually support, that will depend on what the users ask for and what our test pilots are willing to test. Personally, I would not dare to try a pitch and roll rate mode, but if someone else is willing to test it, I am willing to implement it.
Best regards,
Bill
Hi Roy,
the video was shot in the pre-Alpine valleys of the South part of Switzerland.
Best regards,
Ric
Hi Roy,
I will answer your first question and leave the second one to Ric.
For throttle, the control is a straight pass-through, with accelerometer stabilization of vertical motion.
For roll and pitch, the control is fly-by-wire: the stick input is interpreted as commanded roll and pitch. The controls maintain the actual roll and pitch to be the commanded values.
For yaw, the control is yaw rate, stabilized: the yaw input is passed along to the motors, with yaw rate feedback.
The controls are a work in progress. I put the present version together simply so I could get my quad off the ground while I implement my control ideas, but it is performing much better than I hoped for. I expect that the performance will continue to improve as I implement the rest of my ideas.
Next on my list is to extend the fly-by-wire control to include yaw. The idea will be to implement a heading-hold function in the earth frame of reference, similar to a heli heading-hold gyro, except it will lock in the earth frame of reference rather than the body frame of reference.
Best regards,
Bill
Hi, thanks all !
Martint, I would like be there :)
Best regards,
Ric
Excellent, the UDB boards really are turning out to be the boards that can.
Hi Bill,
Yes, I still have the modified board, which I believe started as a UDB2 now that I think about it. It's still mounted on that blue foam wing plane that wasn't meant to last more than a couple weeks, under a significant coating of dust... I've got a couple other UDB boards, but I don't recall whether I converted them to the new gyros or not. I should certainly have the hardware covered, and of course frames are no issue :-)
Cheers,
Rusty
Hi Rusty,
Its good to hear from you again.
By the way, MatrixPilotQuad supports all versions of the UDB, including "Rusty's board":
#define RED_BOARD 1
#define GREEN_BOARD 2
#define UDB3_BOARD 3
#define RUSTYS_BOARD 4 // Red board with Rusty's IXZ-500_RAD2a patch board
#define UDB4_BOARD 5
Do you still have your "Rusty's board"?
Best regards,
Bill
Hey look, it's a UDB quad copter! Good to see some of the old familiar names again. What's really funny is that I was digging through my bag of UDB3 stuff the other day, which made me think to check SF to see if there was a new version. Sure enough, there was a UDB4. Even though I'm not flying any fixed wing, I couldn't resist ordering one, and now I see there's some work on the multi-rotor platform. Very cool! I had really great success with the UDB on fixed wing, and can't wait to see what it can do on multi-rotor.
Cheers,
Rusty
That is great, the UDBv4 just keeps getting better!
Keep up all the good work and all the best with the UDB quad autopilot!
Can't wait to see the finished code!
Many thanks!
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