6-DOF Stewart Platform to be controlled in one month!!

Hello guys,
i am a huge fan of x-simulator software and i know this software for about 6 months or so and now i have decided to built a simulator for me too and this time it will be 6dof :clap:

I have already built a stewart platform with my own actuators having DC Motors from the power windows of the car. i,ll be posting the pics shortly.
i want to design the electronics for my self with the help of a friend.
now i want some serious help from this community to run it as i want to accomplish this task in just one month to exhibit in a local science fair.
i want to use MS flight simulator for the inputs, now can anybody help me how to calibrate this data in force profiler and what should be the first step to be done in Force profiler software. :
regards
Ali

Hi Ali,

Have you worked out the geometrical calculations for the platform?
It would be helpful if you described what you have so far.

Do you have motor drivers? Do you have any experience in electronics? Microcontrollers?

A month isn't going to be enough unless you have most of the design worked out.

Our platform has been manufactured according to the required geometry of the platform.
As far as Electronics is concerned we are building DC motor controller electronics using IRF450 Transistors as our DC motor runs on 4Amps and L298 cannot be used to drive such motor.

Here is the first image of my platform that i want to control with x-sim software



Any suggestions are more than welcome

if having problems with image check it out here

http://www.imgzzz.com/pic/1277147651

This is a nice and economical solution for aircraft. Good job so far!

Thanks a lot, Mr. Niels(Nima) will be helping us in the x-sim part!

I am looking forward to see some video footage.
Great job so far!
I hope the wiper-motors are strong enough to handle at least 1 person.

Regards

I hope so but our main concern is to just interface it with the software and run it in real time.
what electronics would you suggest for interfacing it with the computer.
As the motors are DC!

Tronicgr' AMC motion controller + Hbridge.

But 1 set is just capable of controlling 2 motors, so you'd need 3 sets of AMC and Hbridge.

Regards

it will not be available at ours side so can i have the diagram of the circuit so that i can built it by my self with all the components!
regards

The platform looks impressive for what it is, but I wouldn't put too much weight on it because of the motors.

If your friend can design the electronics in about two weeks, you might have a chance to make it to your science fare. It is going to get very expensive if you build 3x AMC + 3x dual H-bridge, and you still haven't solved the geometrical calculations.

Very cool project and I think it is time more people attempt the steward platform! Even if it is on a small scale, getting it working is already most of the work.

Interesting..... I've always wondered if 6 150mm SCN6's would be enough power for a floater design like this. I realize this might be expensive for this project, but it does sound like it might hold enough weight.

Thanks to all of you for taking interest in our project.
We are also working on the Mechanical model Built with Simmechanics which is already provided inside of Matlab. These days we are also trying to design the PID controller to do some Rapid prototyping using xPC Target toolbox.

For Matlab.....

What i am really exited to know that How should we have to convert The Force values generated by The PID controller to the calibrated PWM voltage signal to send it to the National Instruments DAQ card. Any one have info about it, Plz help us.

Finally @sirnoname
Thanks for your useful info but can you plz explain that why cant we use The standard Math Interface as i have seen some videos of Stewart Platform running completly on the standard software.
Regards
Ali

The standard math plugin takes a single effect, do whatever you need to do to make it work, then output this single axis to the output plugin.

With a steward platform it is a completely different story. One game effect (Pitch for ex) has to move ALL 6 OUTPUT AXIS. Further more, all of the other effects (Yaw, Long, Lat etc) will alter ALL 6 of the output axis. If your actuators are not in sync and not calibrated, they will work against each other and use excess power and possibly damage the whole platform.

I don't think you have seen this done with the Math plugin.

@Sironame
First of off all i am really thankful to you because of you Explanation
and
What i understand from your point is that Math plugin can produce effects only for one axis and for Stewart Platform we have to take care of all the three axis as they are all coupled in Stewart Platform like configueration..is that Right?

Additionally can you please help us with that math pluginn that how to write code As i am quite newbie in Programming!
and what if we just simulate effects in One axis, can we use the standard math plugin in that case?
Looking forward to your Reply!
Regards
Ali

There is a program for a servo arm actuated steward platform on the forum, but those geometrical calculations are totally different than what you have.

If you are good at geometry and algebra, you could come up with a formula and try to simulate it first. I don't think a lot of information is available on the internet because most of the companies using it will definitely not share it. Good luck!

Well there is plenty info on net. if you are good with matlab you can solve equation really simple. You use http://en.wikipedia.org/wiki/Transformation_matrix . If you want study here try this book, its huge, but lots of info. http://www.amazon.com/Advances-Robot-Ki ... 49404#noop

So there it is.

Anyone up for a good reading?