[Suggestion] Spring joystick control.

[Selliese]

If FFB doesn't swing, then why not make the spring stick as stable same as FFB (through virtual force), why should FFB and non-FFB have different gameplay?

[Victory205]

19 minutes ago, kablamoman said:

Here's what I'm talking about. The behavior is there at all speeds and weights, varying at bit of course with aerodynamic loading and moments of inertia, I'm sure, but all showing the oscillating stab.

 

Thank you, I watch the first couple of minutes and I’ll look at the rest of it a bit later.

Quickly. The F14 has a couple of bobweights, springs and an Eddy Current Damper between the control stick and the flight control surfaces, all modified by the SAS computers. The F-4 has a bellows that loosely performs the function of the ECD by increasing pitch forces at high G. There is a lot going on under the surface in the Tomcat that most aren’t familiar with to produce it’s handling characteristics.

Can you give us and idea of your real world flying experience for reference? What general types of aircraft and whether you’ve flow aerobatic maneuvers in the real world.

It’s Memorial Day here and I’m leaving to attend a ceremony for our fallen brethren.

Remember.

 

[Maksim Savelev]

Its not happening with FFB, I can confirm that

[Phantom12]

FFB will of course swing if you let it. Forces generated by an FFB stick are much weaker than the real airplane so its not difficult to hold in place.

Are we sure that the F-4 is not simply more prone to these sorts of oscillations than some of the other aircraft in DCS? If you take a Me 109 up to high altitude or load up the aft fuel tank in the Mustang etc they will bobble around alot more as well. Abruptly unloading tends to aggravate these things.

 

Re the little diamond: my interpretation of that has been that it represents the zero force position for the stick. Of course it will move forward as load factor increases due to the nose down force produced by the bobweights. Once you unload again it moves back to where it was.

Edited May 27, 2024 by Phantom12

[IronMike]

6 minutes ago, Phantom12 said:

Are we sure that the F-4 is not simply more prone to these sorts of oscillations than some of the other aircraft in DCS?

It definitely is, it is explicitly mentioned in the manuals, a lot.

[kablamoman]

5 hours ago, Victory205 said:

The F-4 has a bellows that loosely performs the function of the ECD by increasing pitch forces at high G

Correct me if I'm wrong, but the bellows side of the mechanism in the F-4 only provides stick downforce. It also helps sets the trim stab angle/stick position insomuch as it's the trim actuator modulating said input from the bellows.

The bobweight is what provides increasing stick weight at high G... But for the duration of the stick being pulled, relaxed, modulated, and then eventually brought back to the neutral trim position that we had trimmed by modulating the bellows force with the trim actuator -- the bob weight is being supported by the pilot's arm (helped a bit even, by the bellows' down-stick force). In essence, the bobweight is something to be felt only through the duration and modulation of loads by the pilot's arm -- it does not interact with the bellows except for when pressure is taken off the stick completely, at which point, it should be at 1g and back in balance if the pilot does it right and doesn't simply let the controls snap back.

After further flying I do not believe the bob weight forces -- when being generated by pilot control inputs -- should have any impact on the trim neutral point at all. Because there is no way for the sim to know if the pilot is applying the grip force to keep the stick in place, or if it's the springs and cam of our stick. We cannot simply assume the pilot has released their grip, and so this is where I think there is an error in modelling. It seems Heatblur, in the pursuit of conveying those forces, is taking "returning stick to neutral" to mean "progressively letting go of the stick entirely". You don't pull hard and then progressively let the stick slip out of your hands as you ease off -- you hold it there and bring it back to neutral with some grip/arm strength to support the weight of the stick throughout the motion until you're back to 1g. The imbalance between bellows and bobweight should be completely absorbed throughout the maneuver by the pilot's grip.

Modelling it "properly" in this way would indeed have unfortunate side effects for non-FFB users in that we have to assume the pilot is gripping the stick in place at all times -- it's the only valid assumption we can make without breaking things. For instance, you would no longer see the hands-off oscillation response when trimming, as you would in real life if you were flying with very light, fingertip pressure on the stick -- but that effect should be apparent and preserved for users with proper FFB. Instead, spring stick users would only visually experience a constant pitching moment, which they would then feel if they tried to oppose it against the force of their real-life springs without retrimming (still a great approximation). Likewise, the "dead stick" effects at low to nil airspeed would be appropriately overridden, but still be there for FFB users.

 

Quote

Can you give us and idea of your real world flying experience for reference? What general types of aircraft and whether you’ve flow aerobatic maneuvers in the real world.

I've been flying professionally for 15 years, I started instructing in small pistons (telling students to HOLD the controls tight when they're setting their go-around attitude even though the plane is pushing back), hand-bombed multi-engine turboprops up in the North for a few thousand hours and moved on to the corporate world where I've been flying my non-reversible (non-tactical) hydraulically actuated stab controls with artificial feel for the last 6 years. I enjoy spinning tail draggers in real life and on the World War Two servers in the sim 

I also enjoy star gazing and long walks on the beach.

Edited May 27, 2024 by kablamoman

[kablamoman]

5 hours ago, Victory205 said:

5 hours ago, Phantom12 said:

Are we sure that the F-4 is not simply more prone to these sorts of oscillations than some of the other aircraft in DCS? If you take a Me 109 up to high altitude or load up the aft fuel tank in the Mustang etc they will bobble around alot more as well. Abruptly unloading tends to aggravate these things.

 

Oscillations in that case have everything to do with aerodynamic damping, or the lack of it at low indicated and high true airspeeds (ie. high altitude), or basic stability issues (in the case of the mustang with a full fuselage tank).

In both of those modules, the player's stick retains direct control of the elevator deflection even in those scenarios and so you have a chance at properly damping them (but good luck).

Edited May 27, 2024 by kablamoman

[kablamoman]

1 hour ago, Phantom12 said:

This is great and probably the best counter argument to anything I've brought up. The problem is that when talking about control forces we start getting into fuzzy territory with regards to modelling it on a non-FFB stick. As mentioned, you can control the behavior with an FFB stick, but can't with a regular spring loaded one. This would mean our virtual pilot ends up being endowed with a comparative wet noodle for an arm.

Edited May 27, 2024 by kablamoman

[Baldrick33]

@kablamoman thanks for the video, I found that very constructive and adds to an intriguing topic along with the devs comments.

A bit of a deviation but I have a powerful enough force feedback steering wheel using an industrial motor that on its highest power can simulate a heavy crash that would do some damage if the driver didn’t remove his hands from the wheel. On realistic settings the wheel will move the hands. This feedback generally helps the driver understand the forces being applied like self aligning torque, so is typically seen as an advantage.

That said some don’t like the wheel moving for them and dial down the ffb or run non ffb wheels as it allows for greater precision, some of the fastest drivers use low or non ffb for competition.

I can’t imagine having the wheel movements forced upon an ffb user to counter being applied to a non ffb user, the virtual wheel would move independently of the physical one which would seem impossible to control accurately as it wouldn’t be just visual but steering inputs mismatch.

if I am understanding the points raised it is a similar issue here, beyond just the visual mismatch of sticks but actual inputs?

Edited May 27, 2024 by Baldrick33

[kablamoman]

18 minutes ago, Baldrick33 said:

I can’t imagine having the wheel movements forced upon an ffb user to counter being applied to a non ffb user, the virtual wheel would move independently of the physical one which would seem impossible to control accurately as it wouldn’t be just visual but steering inputs mismatch.

if I am understanding the points raised it is a similar issue here, beyond just the visual mismatch of sticks but actual inputs?

That is correct.

[FusRoPotato]

4 hours ago, kablamoman said:

This is great and probably the best counter argument to anything I've brought up. The problem is that when talking about control forces we start getting into fuzzy territory with regards to modelling it on a non-FFB stick. As mentioned, you can control the behavior with an FFB stick, but can't with a regular spring loaded one. This would mean our virtual pilot ends up being endowed with a comparative wet noodle for an arm.

 

This is the critical point here that I made earlier. When producing compensation for non-FFB users, the general outcome of control smoothness and accuracy should be similar or better than the outcome of users flying with FFB. Otherwise, you end up simply punishing a user for not having expensive hardware.

The strength and dampening effect from the arm of the virtual pilot needs to be able to hold the virtual stick firmly as would someone in the real aircraft, or in the sim with a correctly recreated FFB system. According to mil standards, the forces produced by that stick, including those by momentum of the weights, cannot exceed certain values to prevent control difficulties like this, and thus, the aircraft doesn't kick back very hard. What we should be feeling is approximately what we feel in DCS simulated with FFB, and we are able to hold the stick quite firmly in that case and the sim correctly represents that.

The problem is the weak pilot arm for non-FFB that cannot hold the stick as expected. The loose grip allows for a larger expression of the force feedback without the expected compensation.

Based on a little bit of data logging at various speeds showing consistent and smooth response frequencies at all deflections including center, I assume most all of this reaction is coming from reaction-torque about the bob weights. As you shove the stick forward, you are not just attacking the force of the weights, but also adding rotational kinetic energy. Bringing the stick to a stop while in motion thus requires extra torque. This is easy to feel and counter with and FFB stick but the non-FFB simulation lets it pass and this is what turns into the unwanted oscillations you see that you also can't easily counter. This is also why those oscillations occur at every position, not just center, but are likely exacerbated near center due to how most non-FFB sticks "snap" as they hit center. For people with extended sticks, this may be less apparent as the stick may often not be moving as fast, thus less kinetic energy stored before coming to a stop.

The drop in oscillation amplitude I'm seeing after turning on FFB drops around 90% ish, even though my accuracy to bring the stick to a perfect center with FFB is a little more difficult. That is a big difference. The fix for this problem is straight forward: Fly the aircraft in such a way you can enable and disable FFB, record the pitch response, Increased arm strength and dampening when FFB is disabled until it starts to match the results recorded with FFB on.

I grabbed stick position and recorded data with and without FFB enabled in the game settings. This can be done through export lua using the code
 

testfile = io.open("B:/Users/username/Saved Games/DCS.openbeta/Logs/FlightRecord.txt", "w")
if testfile then
	testfile:write("Log Start")
end

function LuaExportAfterNextFrame()
	local Controls = GetDevice(0)
	Controls:update_arguments()
	local pitchCommand = Controls:get_argument_value(2) -- was 3002
	local pitchmessage = string.format("%.4f\n",pitchCommand)
	testfile:write(pitchmessage)
end

function LuaExportStop()
  if testfile then
    testfile:close()
    testfile = nil
  end
end

And this is the compared result:

I start at 400 kts IAS conditions and simply pitch forward and back over and over. Notice how the squiggle at the end of each pitch command change is much smaller when using FFB. This is because I can fight the force response physically. Without FFB, I am not allowed to do it and the pitch oscillates.

Edited May 27, 2024 by FusRoPotato

[kablamoman]

2 hours ago, FusRoPotato said:

This is the critical point here that I made earlier. When producing compensation for non-FFB users, the general outcome of control smoothness and accuracy should be similar or better than the outcome of users flying with FFB. Otherwise, you end up simply punishing a user for not having expensive hardware.

The strength and dampening effect from the arm of the virtual pilot needs to be able to hold the virtual stick firmly as would someone in the real aircraft, or in the sim with a correctly recreated FFB system. According to mil standards, the forces produced by that stick, including those by momentum of the weights, cannot exceed certain values to prevent control difficulties like this, and thus, the aircraft doesn't kick back very hard. What we should be feeling is approximately what we feel in DCS simulated with FFB, and we are able to hold the stick quite firmly in that case and the sim correctly represents that.

The problem is the weak pilot arm for non-FFB that cannot hold the stick as expected. The loose grip allows for a larger expression of the force feedback without the expected compensation.

Based on a little bit of data logging at various speeds showing consistent and smooth response frequencies at all deflections including center, I assume most all of this reaction is coming from reaction-torque about the bob weights. As you shove the stick forward, you are not just attacking the force of the weights, but also adding rotational kinetic energy. Bringing the stick to a stop while in motion thus requires extra torque. This is easy to feel and counter with and FFB stick but the non-FFB simulation lets it pass and this is what turns into the unwanted oscillations you see that you also can't easily counter. This is also why those oscillations occur at every position, not just center, but are likely exacerbated near center due to how most non-FFB sticks "snap" as they hit center. For people with extended sticks, this may be less apparent as the stick may often not be moving as fast, thus less kinetic energy stored before coming to a stop.

The amplitude I'm seeing of the oscillation before and after FFB drops around 90% ish even though my accuracy to bring the stick to a perfect center with FFB is a little more difficult. That is a big difference. The fix for this problem is straight forward: Fly the aircraft in such a way you can enable and disable FFB, record the pitch response, Increased arm strength and dampening when FFB is disabled.

I grabbed stick position and recorded data with and without FFB enabled in the game settings. This can be done through export lua using the code
 

testfile = io.open("B:/Users/username/Saved Games/DCS.openbeta/Logs/FlightRecord.txt", "w")
if testfile then
	testfile:write("Log Start")
end

function LuaExportAfterNextFrame()
	local Controls = GetDevice(0)
	Controls:update_arguments()
	local pitchCommand = Controls:get_argument_value(2) -- was 3002
	local pitchmessage = string.format("%.4f\n",pitchCommand)
	testfile:write(pitchmessage)
end

function LuaExportStop()
  if testfile then
    testfile:close()
    testfile = nil
  end
end

And this is the compared result:

I start at 400 kts IAS conditions and simply pitch forward and back over and over. Notice how the squiggle at the end of each pitch command change is much smaller when using FFB. This is because I can fight the force response physically. Without FFB, I am not allowed to do it and the pitch oscillates.

 

My virtual hat is off to you, sir. Thanks.

I have also finally put my name down on the list for a VPforce Rhino 

Edited May 27, 2024 by kablamoman

[Maksim Savelev]

4 минуты назад, kablamoman сказал:

My virtual hat is off to you, sir. Thanks.

I have also finally put my name down on the list for a VPforce Rhino 

 

You should consider FFBeast - that's the best representation of FFB concept)

[kablamoman]

1 minute ago, Maksim Savelev said:

You should consider FFBeast - that's the best representation of FFB concept)

Hook a brother up!

I put my name down for the Rhino as it has mounting hardware for the monstertech chair I'm using and it's compatible with my VKB grip -- do you know if the FFBeast offers that?

[Maksim Savelev]

@FusRoPotato Thank you very much for the Great analysis!

8 минут назад, kablamoman сказал:

Hook a brother up!

I put my name down for the Rhino as it has mounting hardware for the monstertech chair I'm using and it's compatible with my VKB grip -- do you know if the FFBeast offers that?

It's Big, Heavy, and VERY powerful, but the downside of it it's floor based. It can be used with VPC or VKB grips

Edited May 27, 2024 by Maksim Savelev

[kablamoman]

10 minutes ago, Maksim Savelev said:

It's Big, Heavy, and VERY powerful, but the downside of it it's floor based. It can be used with VPC or VKB grips

Sounds awesome, but I don't think floor mounting will work for my current setup. I'll keep an eye on development, though!

[Phantom12]

@FusRoPotato Just to clarify did you actually use an FFB stick in this test or just turn the setting on and try it with a normal spring stick?

[CapnCoke]

1 hour ago, kablamoman said:

Sounds awesome, but I don't think floor mounting will work for my current setup. I'll keep an eye on development, though!

Seen a user reviewing the FFBeast with the F18, and he required two hands to do certain high aoa manuevers. Rhino peak torque is at 9 Nm while FFbeast is at 32 Nm so yeah it does need a solid mount.

[FusRoPotato]

2 hours ago, Phantom12 said:

@FusRoPotato Just to clarify did you actually use an FFB stick in this test or just turn the setting on and try it with a normal spring stick?

I couldn't figure out how to fly non-FFB stick with the FFB option enabled. The FLCS and trim wouldn't let me trim level flight and it became really difficult. Kept wanting to pull up really hard. I'm not sure yet what to do with that. At center, it was pulling up harder than what I pulled in the tests, so in order to replicate it, I have to hold the stick in 3 different forward positions, but it was very hard to hold it. Wobbling all over. However, I was getting the impression that the oscillations might not have been present. It felt like it was more direct. I just couldn't control or trim it.

Actually I have an idea, I'll try trimming it with the in-game curve profile... after my BBQ

Edited May 27, 2024 by FusRoPotato

[FusRoPotato]

3 hours ago, Phantom12 said:

@FusRoPotato Just to clarify did you actually use an FFB stick in this test or just turn the setting on and try it with a normal spring stick?

It worked. I set the curve in the options to 19 low and that brought my trim to roughly center. I then recorded it. However, flying like this is a little impractical because there is no way to trim when there is no trim force. The result was, zero oscillation. The virtual stick matched my non-FFB stick exactly. Eve though there is a little pike present at the end of every change in position, that was my fault physically trying to bring my stick to a sharp stop and over correcting.

 

Pitch Response non-FFB with FFB option enabled for F-4E release @ ~ 400kts ISA

Edited May 28, 2024 by FusRoPotato

[Maksim Savelev]

Thank you! That is exactly what we’re trying to say all the time. It should be zero oscillation. The only reason why this aircraft could be a subject of PIO is because it doesn’t have a «variable ratio» between stick and stabilator which along with the aft CGs and thus a high effectiveness of the stabilator makes it hard to precisely control it at a high IAS. Next gen of jets have eliminated this problem by implementing this stick to stabilator variable ratio based on speed. Of course, inertia of bob weights counts but I believe the major part of it will be damped out by the system itself and the rest will handle the pilot. I also believe that damping conditions are underestimated by HB, because even removing a viscous damper later on, to reduce the system resistance and thus increase speed of trimming, couldn’t be felt by pilots. But nevertheless the small one/two time (one/two period) osciillation or fluctuation is expected when position of the stick is changed, because pilot needs to readjust his pulling/pushing strength wile also dealing with the inertia. But  it will happen anyway, even you're using a simple spring joystick, you can see it from the latest FusRoPotato's graph. So no need  to  bother to fake it through the simulation of flight controls. 

It would be absolutely great if we can get the same opportunity as @FusRoPotatoshowed here, but with possibilities of old fashion trimming. As I’ve showed in my video, the range of required positions of stabilator required for the horizontal flight throughout the whole speed envelope is very narrow and basically ones trimmed you barely need to touch it again, might be just slightly for the comfort purposes when stabilized on speed in landing configuration 

Don’t get me wrong I’m talking about light spring loaded joystick. Real aircraft you will need to trim, because forces are not the same. But it applies almost for every aircraft 

Edited May 28, 2024 by Maksim Savelev

[Maksim Savelev]

10 часов назад, CapnCoke сказал:

Seen a user reviewing the FFBeast with the F18, and he required two hands to do certain high aoa manuevers. Rhino peak torque is at 9 Nm while FFbeast is at 32 Nm so yeah it does need a solid mount.

Well, not really. 32 as I understand is a weakest option. With the most powerful motor, slightly different gimbal, and arm of 45cm (length of stick + half length of grip) I’m getting max of about 55 lbs in a pitch channel.

Edited May 28, 2024 by Maksim Savelev

[Baldrick33]

14 hours ago, FusRoPotato said:

It worked. I set the curve in the options to 19 low and that brought my trim to roughly center. I then recorded it. However, flying like this is a little impractical because there is no way to trim when there is no trim force. The result was, zero oscillation. The virtual stick matched my non-FFB stick exactly. Eve though there is a little pike present at the end of every change in position, that was my fault physically trying to bring my stick to a sharp stop and over correcting.

 

I just tried taking off and landing both with FFB on and off (using a spring Virpil stick). No trimming.

Just watching the AOA needle I found it much easier to maintain an AOA within range with FFB on. With FFB off I would move the stick so the needle moves to the right place then the virtual stick would move so I was constantly chasing it. Comparing back to back there is quite an impact beyond just visual representation of the stick.

[Renko]

1 hour ago, Baldrick33 said:

I just tried taking off and landing both with FFB on and off (using a spring Virpil stick). No trimming.

Just watching the AOA needle I found it much easier to maintain an AOA within range with FFB on. With FFB off I would move the stick so the needle moves to the right place then the virtual stick would move so I was constantly chasing it. Comparing back to back there is quite an impact beyond just visual representation of the stick.

Maybe something weird is going on with DCS itself.
Because i tried the same thing with my Virpil, and it behaves the same. FFB on or off. In Misc. Option, and even with the FFB options on the F4 Special Menu

Also i dont see spikes seems smooth to me when moving the stick in pitch. But i dont have that meause tool, so its hard to tell 100%

[Baldrick33]

2 hours ago, Renko said:

Maybe something weird is going on with DCS itself.
Because i tried the same thing with my Virpil, and it behaves the same. FFB on or off. In Misc. Option, and even with the FFB options on the F4 Special Menu

Also i dont see spikes seems smooth to me when moving the stick in pitch. But i dont have that meause tool, so its hard to tell 100%

For me it is really easy to see. FFB on (in Misc) and the stick is centred on the runway, off and it is dropped forward. More subtly as you fly pitch forward and watch the virtual stick move on its own back (FFB off). With FFB on the virtual stick moves as per the physical stick.