The Shop > Electronics & IC Programing
Electronic stabilization systems. aircraft el al! Link Trainer.
PekkaNF:
There are many ways of implementing this kind of functionality and it depends a lot from mechanics how easy it is to get representative indication of attitude straight from the mechanics (or even from actuators). I know one application that went trough the whole cycle from cascaded servo control AND final position measurement to very rigid structure and using only measurements from servo to it's latest iteration of advanced servo and separate from feedback loop magnetic encoder distance measurement again. It all boiled down to a how rigid the structure is in relation to accuracy demand and how economical it is to make different systems to communicate with each others. Programming and interfaces are easily more expensive than transducers in low volume products.
Interfaces/signaling and programming is something that needs good though.
I do agree in principle on Steve's comment on using transducers. That would be in principle very straightforward engineering solution on gimbal system or when there is a rigid mechanics.....From contents I gathered that some thin wall steel (furniture) pipe and plywood might be involved.....that leads easily thoughts on flex/jerk and other inperfections in linkage and then measuring the attitude/acceleration of the platform might be actually most elegant solution after all.
I have no idea if a game controller could be hacked and used as a proof on concept. These simulators are foreign to me.
vtsteam:
I assume it will be rigid enough not to upset people, and plywood doesn't mean inordinate flexibility, simply depends on design. All kinds of rigid structures are designed in plywood. Including many famous aircraft, which in fact will be the kind of vehicle modeled. DeHavilland Mosquito and Spruce Goose are notable all ply examples, then there were PT boats, and more recently famous IOR racing boats like Golden Dazy, racing iceboats like the DN class, etc, etc..
You can smooth inputs in software as well as choosing an appropriate line rate encoder for the reasonable rate and extension movements needed. I don't think the museum will be simulating crashes or real speeds! The information fineness and rate are going to be very reasonable. There's really no inherent problem in using scales and encoders. I can think of plenty of difficulties in using model type gyros though. Hey a guy has already gone through this, right? And is still not there.
You will definitely need failsafe software in either case to limit movement rates, and have a safe automatic shutdown routines if sensors provide out of norm expected results, or fail. Movement rates and extents will need to be very limited, etc. But I'm sure you know all of this.
vtsteam:
The real thing:
John Hill:
All this interest in my scheme is very gratifying indeed!
PekkaNF The alternative gyro devices are very interesting although I will not make a meal of detailed research just yet, not until I have mentally come to grips with the first suggested device.
I take your point about deriving position from actuator signals (open or closed loop) but that does usually introduce the need to read absolute positioning at start up, depending on the type of actuator of course.
vtsteam, I have spent a few bux on those encoder devices already and they sure make construction of an anemometer a real breez but of course one must use an absolute one for direction and incremental for the speed, or at least that's the way I do it.
The attraction I see for a gyro (or like device) is that one little device can provide all the attitude information without the concern of running wires hither and yon and slip rings.
awemawson, I like the plastic dish and ball bearing idea and I am almost tempted to include one somewhere even if only for show!
Well yes, plywood, steel and recycled bed sheets will all be included in the build. There will also be a F&P washing machine motor, a drive shaft complete with Hook's joint from the junk yard and various curiously clever devices from the John Deere wrecker. Plus I now know why I have been storing a radar rotator from a ship's masthead all these years.
I assume that is Mr Link's patent drawing? What a wonder grew from simple beginnings!
Thanks for your interest, information and suggestions.
vtsteam:
--- Quote from: John Hill on May 13, 2022, 04:10:08 PM ---The attraction I see for a gyro (or like device) is that one little device can provide all the attitude information without the concern of running wires hither and yon and slip rings.
--- End quote ---
Heh, I just completed a DRO over bluetooth project. accomodates scales with absolute positioning also quadrature inputs, and even has battery backup for scale positions if the power goes out.
CNC doesn't use slip rings, but also wouldn't the encoders be at the gimbals and not in the trainer body?
Bluetooth serial xmitters HC-05 or HC-06 are like $5
There's an open source firmware sketch for Arduino for the above DRO project here:
http://rysium.com/projects/196-arduino-dro
and construction:
https://www.yuriystoys.com/p/arduino-basic-dro-controller.html
I don't know what the UK rules are re. model aircraft frequency telemetry of gyro data for an alternate use.
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