Motorized Joyrider

[TronicGr]

Hi kjg71,

I have posted detailed photos of the motor connections on my robotics forum:

Motor to pulley connection:
http://www.ptyxiouxos.net/greekbotic...ic.php?1070.50

Motor to racks connection:
http://www.ptyxiouxos.net/greekbotic...c.php?1070.100


The pitch motor is fixed on the bank cimbal as seen here:
http://www.ptyxiouxos.net/greekbotic...c.php?1070.120

The car wiper motors, I use, have worm gears and hold their position when they powered off no matter how force you apply to them. They are from old Nissan 85' model B-11.

No, the HB-25 just needs a standard servo pulse that sets the motors direction and speed. It should work fine with velleman. But you have to implement some short of proportional control code to position it on the desired angle since you must play with speed, not position like standard servo.


Are you making motion cockpit too? Any photos of it?

Regards, Thanos


PS. If clicking the above links doesn't work, copy the links and place then on a now iexplorer window .

[Jim NZ]

Hi Thanos,
Yes I got the code and thanks a lot for it. Had a quick look and it seems not too bad to get ones head around.
Will study it at the week-end and refer to the manual etc ,,, certainly looks promising. ,, especially the HB-25 units, didn't even know such a unit existed.

There are getting more and more possibilitys out there now with so many simmers getting into motion, it takes a wee bit to keep up with the play.

Great stuff !!! It all helps to keep the gray matter working !!!
Will get back in touch if I go down your interesting road.

Thanks again Thanos ... Jim

[kjg71]

Hi Thanos,
thanks for those links. That was exactly what I was looking for. I am using window motors and they do not have worm gears to hold so I may need to investigate the wipers. Another person used those a while back for a g-motion similator and they are gaining popularity.
Right now I am using EZIO and velleman I/O boards for simplicity.

I can use PWM in locked antiphase mode for a one-line speed control of motors up to 5 and 7 amp (6 and 20 amp) stall. Which is working fine but I like the versitility of the HB-25 and it is about half the price of my 7 amp (20 max) bridge and will do 35 amp max. wow!

Be interesting to see how this performs and if it takes a variable voltage. I question how to do reversal though, if the controller isn't set up to do things that way.

For $45 it's almost worth just getting one to see.
to help clarify I send 0-511 for off to full clockwise (511 is full and 256 is half speed) then 512-1023 for the same but in the other direction (Counterclockwise)...not sure how the HB-25 is going to handle that?.....if you have any comments on that, it would be welcomed.

currently:
For low amp motors I am using NMIH-0050
For med/high amp motors I am using D-rex controller
see new micros site under H-bridge catagory
http://www.newmicros.com/
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For med/high amp motors that do not need speed controll I am using a custom circuit with auto relays and a Current TTL DriverBoard. I should be able to make these for $12 each they can handle 30 amps and with full reversable - no speed controll though. this is for motors where their top speed is going as fast as they can and you don't need speed control or washout. example power seat chasis for heave or small bumps etc.
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working on polishing up my site more but I do have a year old video that turned out pretty good. Let me tweak some things and I'll post a link asap
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This whole project started as a way to add motion to movies so you would have "feeltracks" that would provide 2-5 degrees of freedom, but then it turned into a gaming system thing and then I am working on adding environmental effect as well.

As many already know here in the forum ...these projects can consume you.....but I am still trying to stay on-track (hard sometimes).

Right now I have yaw and pitch working (the easiest) and are wrapping up surge and heave...and then finally roll and g-motion (a slight variation of the roll module)
also are adding pedal attachments, yoke/wheel attachments and other things that are detouring me from getting the motion stuff done

Like many of you I am trying to create one of the first or (one of the now many) affordable motion systems.....I think it has been long overdue
The difference with mine is that I am really looking to enhance movies as well as non-sim flight and racing games (there are alot of good titles - even older ones out there)
The design, once I get a few things tweaked is quite simple compared to some of the elaborite cokpit ideas but I am gearing it to work with racing and space as well as flight sim/games and with motion there is somewhat of a weight trade-off too

I am looking at more of a flight/race chair with attachments for all the extra controls etc.....going after something that looks good in a living room (or at least acceptable

Currently, I only support game contoller control at the momement.
Was talking to Craig T. from I-vibe about some game data incorporation as well as incorporation of his i-vibe seat with the movie tracks, but things have been slow on that path.
Many thanks to the innovators like Jim, Roland, Craig W. and yourself (as well others, of course) for what has been done so far with motion!

I also have to tip my hat to tornado-blu (don't really know his real name) for his success (see his site below)
http://digilander.libero.it/tornadoblu5/index1.htm

I think everyone can agree that with what we have seen so far $500-$1500 full motion is on the way!
standby I'll post a link to my project soon.....just want to tweak a few things first.

Regards, Kyle

[wannabeaflyer]

Hi Thanos managed to get hold of a tutorial on basic stamp and wonder if it would be possible for you to send me a copy of the code so that i can see if i can get my head around your option ..Kinda like the idea of the modular approach your option offers as i tend to look at whats out there and see if its something that i can use... in my motion sim .... i already have aset of IOcards servo and Motor driver pcbs and wondered if i could use th HB-25 to allow me to control my motors Cheers got the data sheets on the HB-25 and Pic stamps so like jim will see if i can match things up

[AndyT]

ARRRgghhhhhh !!!
You beat me to it!
I'm re-building my pit into a joyrider with motion. I have 2 12v wheelchair motors to use for the drives and I plan on building the joyrider in such a way so that I can add yaw to it later much like what Jim has built.

One of these days I'm going to have some money AND time to work on it both at once....

Thats just beeeutiful man! I love it!

[TronicGr]

Hi Kyle,

>to help clarify I send 0-511 for off to full clockwise (511 is full and 256 is half speed) then 512-1023 for the same but in the other direction (Counterclockwise)...not sure how the HB-25 is going to handle that?.....if you have any comments on that, it would be welcomed.<

Wow! you have 1024 bits resolution on positioning?! I only use 8-bit resolution aka 256 points with 127 center. I don't know the programming of the microcontroller are you using but I think you could output a simple servo pulse within these values. For example to output a servo pulse in basic stamp2 I use the 8-bit variable input from computer along with an offset value that centers the servo: {8bit_input} + ({offset} - {8bit_input/2}) *where offset is 750 in BS2.

Likewise in your controller you have to find the center servo pulse that stops the motor and then add the input values. If nessasary you could scale down the resolution to fit the servo pulse within the 1ms - 2ms range. Its simple math. Keep in mind that the HB-25 works with setting its speed not its position, and feedback control is nessasary to actually position it. I've implemented such a feedback servo using proportional math to control the speed and its direction until it reaches the desired point and its speed gradually is set to zero. I could make it respond ever faster by increasing the proportionality constant but that stressed much the motor and the power supply requiring more than 15 amps in sudden moves.

I've also seen tornado-blue's motion sim before but I was already had made the joyrider. And on top of that I could not find and blacksmith capable of making the frames like in his design. I made mine in a room in my home with no special tools. All parts are just bolted toggether!

Anyway, looking forward for photos or vids of your setup!

Regards, Thanos




PS, Calvin, I already PM you my email to contact me.

[TronicGr]

I plan on building the joyrider in such a way so that I can add yaw to it later much like what Jim has built.

I would like to have it move in yaw direction too! For now I combined the yaw forces into the roll to simulate the inbalance of center of gravity if you perform a non-coordinated turn (see the turncoordination ball instrument).
Feels good but if the whole platform turned around like Jims, would be excellent!!

PS, Sorry AndyT!!

Cheers, Thanos

[kjg71]

Hi Thanos,

actually the one EZIO brand I/O board is 10 bit for pwm and 8 for all digital inputs and the Vellamen K8055 seems to be 8, but could not find the specs for vellemen pwm so I am assuming 8.

as mentioned I am only working with game controller control and as such are not requiring encoders for positioning as it is strictly a "follow the stick" deal....or button...throttle...whatever.

I have limiters and did have an optical centering sensor but they are just digital switches that keeps things in check (and from stopping the motor)

When I do eventually add encoders (and they will be needed for game data control or at least good data control) It can detect 1024 positions but I would say it's less sensative then that.

This is the same with pwm output. A speed of 66% does not seem much different then 70% to me. At 77% I can see the change. I think it has alot to do with the equiptment and stress on the motors/mechanics to.

What I have (on the EZIO board at least) is a constant pwm at 18Hz

see specs this might clear up things.

http://www.ezio.com/support/specifications.asp

I think I get what your saying...but when I send 256 (my half speed clockwise, it doesn't really stop at that position like a servo, it just continues.....so I have direction and speed but not positioning via the pwm line. Stopping is 511.

Now after reading your 2nd paragraph I think I see what you are getting at. You are describing taking the inputs of the encoders (if and when I add them) and calculating the position vs how far it needs to go (assumes speed never changes) to get to where the new position should be. Kind of turning a gearhead motor into a servo?

Kind of a high-end industrial servo but on a budget?

....so anyway it sound like speed and direction might work ok with HB-25 with pwm varible voltage line...but maybe I am still wrong?

here is a link the the vellemen board if interested

http://www.velleman.be/ot/en/product/view/?id=351346

There are a number of languages you could use with these boards but I am using lingo for the programming. This is more then likely a very non-familiar language to many here as it is a multimedia scripting language similar to basic I guess.

The whole project was to be motion movie tracks and timeline based triggered motion, so I am using lingo inside Macromedia director as it allows you to control scripts with game controllers, sound triggers and inputs from external sensors. The game controller efforts was taking it that extra experiemental mile.

I will not use this environment for "game data" control as I will need to use x-sim, a forum users solution or I-vibe to help with that.

I foresee pros and cons of both control methods but are trying to get all motion and mechanics ironed out before diving into the hardcore "game telemetry" stuff.

I'll try to get my site updated soon and send out a link.

Regards, Kyle

[TronicGr]

....so anyway it sound like speed and direction might work ok with HB-25 with pwm varible voltage line...but maybe I am still wrong?

here is a link the the vellemen board if interested

http://www.velleman.be/ot/en/product/view/?id=351346

Well I checked the velleman... You have to connect the HB-25 on a digital port and pulse it within the 1ms ~ 2ms range, with 1ms center that stops the motor rotating either direction. I suppose you can do this in programming. Don't use its analog ports cause they only output voltage, not frequency.

Yes, what I have implemented is a big servo! With basic stamp its tunning is very easy. I can adjust the reaction speed or the mount of ramping near the end stops, something simple servos can't do! Feels good in its motion too!

Cheers, Thanos

[TronicGr]

Hi Thanos managed to get hold of a tutorial on basic stamp and wonder if it would be possible for you to send me a copy of the code so that i can see if i can get my head around your option ..Kinda like the idea of the modular approach your option offers as i tend to look at whats out there and see if its something that i can use... in my motion sim .... i already have aset of IOcards servo and Motor driver pcbs and wondered if i could use th HB-25 to allow me to control my motors Cheers got the data sheets on the HB-25 and Pic stamps so like jim will see if i can match things up

Calvin, please check your PM...

Rgrds, Thanos