Hello! hope you are doing fine.
Ive recently finish building a rather powerful set of force feedback pedals based on real GA Twin pedals.
Also im about to finish the Yoke as well.
It consists of BLDC motors and controllers for each axis. This is all controlled via some code and interacts with the flight simulator which is X-Plane
At the moment ive written some code that interacts with the flight simulator, and basically changes the forces on the controls based on speed. The faster you are going the stiffer they get.
Im happy with the result, is much better than the more common ‘spring’ loaded setup.
However i would like to improve it. They are always straight , and that is not realistic in my opinion.
these are the 3 basic parameters i can modify:
1) position of the axis, aka move the axis to a desired position
2) Position Gain, aka how much it will resist to changes in position from the desired position. the higher this value the higher the force will be to center it back
3) velocity gain. aka how much it will resist to changes in velocity, this would be something similar to ‘viscosity’ (aka moving your hand in water versus air)
Im looking for advise on the behaviour of the controls, and how the world/events affect them. (mostly GA, single/twin prop piston and turboprop)
for example
> on some planes on the ground the elevator will move all the way forward due to the weight of the elevator. When you pick up speed the elevator will center itself.
> on some light planes wind gusts will move the ailerons on the gound
> on single engine airplanes on takeoff when you apply full power the right rudder seems to be much stiffer than the left one
> on twin engine airplanes with one failed engine one pedal seems to be much stiffer than the other one.
> when you taxi over grass/bumps the pedals will move according to those bumps
Im looking for ANY advise on these kind of effects, and some guidance of the behaviour of the controls. Ideally coming from real world flight experience
I will try to program these into my code to for a more realistic experience.
Thanks a lot!!!
My (ex) company did exactly this as one of the product lines, however only for high-end simulators. PM me, and I can set up for you to talk to an engineer there to give you some pointers. I need to check whether the current owners would be OK to provide you with information but I’m pretty sure they won’t see a problem. One important pointer would be to use force as your primary input parameter. Pilots don’t fly their aircraft by placing a the primary controls in a certain position, they use their feel..
A bit of history which may be interesting to you, starting decades ago..
We found out that airline pilots complained that the aircraft controls of Full Flight Simulators did not feel enough similarity to the aircraft, and that this actually lead to ‘negative training’. Two inventions remedied the situation:
-using force as the primary control loop input rather than position
-using frictionless (hydrostatic) actuators to mimic the forces on the controls.
We started marketing this product along with the service to adapt it to the specific characteristics of the customer’s aircraft. Later, as in so many sectors of the industry, the advent of digital computers, software and electric rather than hydraulic drives transformed the product into a small and easy to maintain package. As you may know, the hydraulic pump room of a FFS is a mess. When we then started to market electric motion platforms many people thanked us on their knees 
I guess by now the company must have sold close to 2.000 of such Control Force Loading Systems, and the price for each such a system goes for way into the 6-digits, even did a 7-digit one I recall. So this is really not at all meant for the hobbyist..
Just to prevent you start thinking we were rip-off artists, here’s what a typical project entailed:
-analyse the electro-mechanical configuration of all aircraft controls (pilot controls to aerosurface) that needed to be simulated (from the AMM)
-do ground measurements on the aircraft (static and dynamic, with a specially developed measurement kit)
-model all components of the control system of the aircraft
-liaise with the sim manufacturer as to where to mount the actuators, and design and build linkages to the control columns if needed
-couple the system with the simulator host computer
-final acceptance testing (part of the level D certification of the simulator), including control force measurements with the aforementioned measurement kit
As you may imagine, the main purpose of training simulators is to simulate malfunctions. So there’s where these professional kits need to excel. Imagine loss of hydraulics (heavy controls) or a broken cable (no force at all!), or jammed controls on the pilot side (procedure: disconnect pilot and co-pilot controls so that co-pilot can steer the aircraft). Talking about loss of controls, we had quite some fun simulating the numerous failure modes of the A-10 Warthog, which is designed to keep on flying even if half of the aircraft is missing
We did this for airliner simulators, but also for helicopter (and car) sims. In the end the military became the biggest market, and the ability to provide a package of with electrical motion (and later G-seat/G-suit sim equipment) became a real asset. We also supplied quite a few systems to research labs, where we would sell them a tool kit for them to build their own aircraft controls configurations in their sim.
We had lots of fun, and made quite a few bucks along the way, nothing wrong with that combination.
aart wrote:
We had lots of fun, and made quite a few bucks along the way, nothing wrong with that combination.
Amen to that, the Holy Grail!
Thanks for your answer!! ive sent you a PM
Ive checked the notes of my motor controller, and i can set up ‘torque’ as well. The controller has may operation modes, and its very powerful
thanks.
