Roll axis drive: what feels most realistic?
Hi Craig,
Good job on the website, lots of good info available there.
Keith is currently tweaking his portdrv utility, lot's of posibilities! so we're busy testing and tweaking the roll axis drive of the platform drive. Since I use software driven DA converters that drive the roll and pitch servo, there are lots of options to get the best results.
In my experiments I started with the roll angle movement derivative (roll drive based on New - Old value), and when I did tests with the Extra, it was maybe OK, (Red Bull Race effect) but for cessna's and bigger planes, you hardly have the jolt when starting a roll, but your head will give you this funny out of balance rotation feeling during the roll from 0 - 30 degrees. I found that when adding the actual roll signal to the drive, it simulated this feeling, but I needed to do something to get the back to center washout.
As far as I can tell, you and Jim are using the following system: When the readings new - old become > 1 you start to move the platform in (say positive) direction with a certain fixed speed. When new - old become < 1 you enable the back to center drive.
In my case I could make the platform speed dependend on the the value of new - old. To avoid overdrive when the platform drive seems to come close to the extremes, this positive roll drive has to gradually flatten out.
I tend to believe that this roll action does not need to be fast: Maybe the actual roll signal to the servo drive will do.
Then when new - old becomes 0 we start the washout back to center. I think the start of the washout has to have soft-start, so it is not a sudden motion back to center, and the washout movement has to be slow, (how slow?) as the occupant should not notice the washout.
Washout going completely back to zero? --> Actually in a steep turn (like a glider) I found that having the platform still slightly tilted to one side is helping you to get that "being in a turn" feeling (together with pitch up for back pressure)
Do you have any advice on the above? Roll speed, washout speed, start and stop of washout, combination effects, ect.
Thanks!
Roland
Motorized Joyrider motion cockpit builder
Hello to all, I'm building a motion cockpit based on the Joyrider design. Right now I'm in the process attaching the motors (car wiper motors).
Here is an early weight test video:
http://www.ptyxiouxos.net/greekbotic..._ride_mfs1.zip
I'm a beta tester of the Portdrvr (dll) by Keith Daniel and right now I'm testing its modifications to add some washout. This is the software I'm going to use to move my cockpit soon. Roland is with us on this too.
Here some interesting videos I took when tested the code with some small hobby servos:
http://www.ptyxiouxos.net/greekbotic...esna1_test.zip
http://www.ptyxiouxos.net/greekbotic...ftoff_test.zip
Regards, Thanos (Greece)