Direct lean setting and bike physics... Help

[davidboda46]

Been following this discussion and decided to do some quick tests with my rig. At 75 DL the "standing the bike up wobbles" were pretty much completely gone. The problem is that the steering feels sluggish and unprecise, like you have an input lag, which is basically what less DL does if I understand it correctly. At 90 DL the wobbles where still almost non-existent, but still the delay feels weird. I guess when you've gotten used to the bike reacting exactly to your inputs it is pretty much impossible to have a good feeling with anything less than 100 DL.

Cheers,

David "Gonzo" Boda #46

[Vini]

i realize that it's not an easy mod (and probably unpractical / too expensive for the average user) but it's still nothing close to the complexity of a full bike rig on which you sit, which DD suggested is necessary for a "full sim system".
my comment was specifically about the ergonomics of the controller, which shouldn't change if you introduce a real steering axis.

max, i'd love to read some excerpts from those emails.
very much interested in the design principle you came up with!

[HornetMaX]

max, i'd love to read some excerpts from those emails.
very much interested in the design principle you came up with!

There's not much more than what I said: a bike frame that leans left/right as commanded by GPB (i.e. aligning the real frame to the virtual frame in GPB).
After that, the real frame has a steering head with handlebars. The head rotation angle is fed into GPB as steering angle (DSA).
On the steering axis there's a FFB device fed by GPB's FFB signal.

With that setup:
- You dictate the steering angle (handlebars angle) to GPB, which will convert it into a torque that tries to realize the angle you asked (so from that point of view, it's less pure than DST, in which there's no virtual rider at all).
- When GPB bike wobbles, your handlebars will wobble too. More generally, your handlebars will more or less do exactly what GPB handlebars do: they are kind of mutually tracking each other.
- When the GPB bikes leans, your frame leans (this is costly and can have some safety issues). This is optional, you could do without.

If you drop this (lean), then you have a system more or less as ddcc's one, but with a different principle: on the paper, it should be "closer to reality" (note the quotes), but until one builds it it's hard to tell if it will be any better.

I don't expect the tuning of all this to be particularly simple, but hardware-wise and in terms of interfaces, it's not too complex.

[Vini]

i would try to keep DD's original design because I think it's a brilliant way of having accurate lean angle while not requiring you to lean your body (on a movable bike chassis) because the handlebar is doing this movement for you.
meaning using a rotatable, cylindrical arm instead of the current fixed one, controlled by gears.

so if i understand it correctly you have kind of a "feedback loop" on the steering axis, correct?
you have a constant force output (either just because of the gyroscopic force simulation or because the rear is sliding, making the handlebar countersteer in one direction).
if you push against it in one direction, you have a specific resistance and the game can calculate what your input steering force was because it knows what the original force output was and what the new steering angle is.
then GPB does it's simulation thing with this input data and sends the new force output to the controller.

i wonder if delay between steering input and output could cause problems?

[doubledragoncc]

Vin you do HAVE to lean your body with my system. When the bike is lent over in say a right curve, my head is no longer in the center of my screen(for reference) it is at the outer right edge and lower down as I am leaning with the bars keeping my body as I would on a real bike. I do not sit just upright and ride, I have to lean as on a bike.

On my sit on systems even though they are static, due to the greater lean angle of the bars compared to a desktop system, I would be actually part off the seat to the right and have my left knee stopping me from falling of by being against the gas tank as basically on a real bike.

DD

[Vini]

ok even better.

you are automatically leaning your body which should change the pressure distribution on your seat. so if you find a reliable way to measure this pressure distribution, you should be able to use it as input for the in-game rider-lean.

oh and i was comparing the amount of required body movement of your system to one without the long arm, which makes the handlebar move "around you" instead of remaining in the same position. so the arm takes enough movement away from your body that the system is ergonomic. btw, is the arm length on your system adjustable?

[doubledragoncc]

What people dont realise as they have not tried it, is that if you have the bars moving as on a real bike, when you and are lent all the way over to one side, because you are not actually on the road riding and there are other forces at work, because you are lent to one and not actually moveing, your body wants to fall straight down to the ground and you will find yourself having to hold onto the bars in an un natural way and it causes you to put pressure on the bars in a way that would then just totally turn then in the opposite direction to the corner(counter-steering) BUT ALL the way which would kill you on the road!!!
This means you will lose that control over your input for steering because your whole body weight is going against the handlebar end!!! You now have NO control and have crashed!!! End game.

This is one aspect forgotten by a lot of people and it makes it harder to use the axis as it should.

And yes I tried it and ended up on the floor!!!

DD

[Vini]

that's why i would keep the arm (your general design), although adjusting it's length (and therefore the amount of left-to-right movement the handlebars are doing) could improve comfort for the individual user even further.

[doubledragoncc]

Not sure what you mean by ARM but we are OT again and H is gonna sabotage our bikes!!!

David explained it right about how the lower DL% helps wobbles but it is like riding in MotoGP or RIDE where I have to make an anti-dead-zone to have some sort of control over the bikes. This is why, although maybe wrong for other control systems increasing it would be a real help for systems like mine using full potentiometer rotation ranges.

Because I can change the gearing on all my axis I can also tune the throttle to respond better to maybe reduce wobble if need be due to too quick throttle response.

DD

[Vini]

Not sure what you mean by ARM

[doubledragoncc]

It took a long time to find the right length for my SPSS I will not change it!

Please understand Vin. I did not just come up with a simple idea and make one system. I have put £1000's into this and tried all different adjustments. This is years of work and experiments. If only I had the money for all the parts and materials that never get used again lol.

DD