Using Response Curves for Controllers in X-Plane 11

okay hey austin meyer coming at you from mike's playhouse x-force pc mike is here with me i am here he is here okay so mike here's the deal a customer of mine uh he emails me about every six months or so saying austin the vertical speed in the cessna 172 is too sensitive and then he shows me videos if i'm kind of doing this on the yoke and the vertical speed in the 170 going around and when i saw this you know anybody would look at this and say oh well the vertical speed indicator is too sensitive i know there's something else going on here okay so the first thing is i looked at this video and i looked at the vertical speed and i measured that feet per minute you know right there off the gauge it's a thousand feet per minute let's say you know he wrapped up to a thousand feet per minute and held it there for three seconds what he said is the vertical speed's too sensitive the altitude is not you know agreeing with the vertical speed if if he goes up to a thousand feet per minute first for six seconds six seconds is a tenth of a minute so boom you see you did the math you can do the math i can't do that exactly so if he goes wrong for three seconds how much should the altitude change if he goes up to a thousand people for three seconds 50 yeah exactly so you can do the math so he sent me this video it's like awesome there's too much vertical speed it's not agreeing with the altitude and so i did that math i was like well hold on how many feet per minute you know a thousand feet per minute for three seconds wait a minute the altitude changed by exactly 50 feet you know we kind of went whoa to a thousand feet per minute for six seconds the altitude changed by exactly hundred feet the vertical speed indicator is working perfectly and i i already knew it was obviously so why is he complaining why is he saying the vertical speed is wrong i mathematically prove that it is perfectly hooked to the l you know to the altitude it ain't wrong so why is it going up and down like this what's what's the real problem here well my guess is when he's flying in a real 172 he puts in a certain amount of input in the real 172 and then when he gets into the simulator that same amount of inputs giving him a different amount of vertical speed change okay so how do you measure this input that you're talking about okay so you're you're red-hot but here's what's really going on he's not putting in the same input in the sense the simulator in the real airplane here's why when you're in the real airplane the resolution of that joystick is basically infinity right it's infinite resolution and as soon as you pull back even one or two percent you know one or two percent pull back on that yoke you start to get a little bit of a g you know and you don't keep pulling back and so you're always operating in the airplane at low speed excuse me at high speed at cruise speed with very small deflections and somebody might respond to the video oh i moved the yoke all the way in the 172. you know well maybe at minimum controllable airspeed or something but at cruz speed it's very very small yoke deflections you know in the order of a few percent because as soon as you start to deflect it and that g load comes down it's just natural to not keep pulling back i mean you'd have to be drunk or something you see but in the real air in the simulator in the simulator does is that what happens no you have to wait for your eyes to see the horizon move and it down which doesn't happen immediately you feel it before you see it yeah you feel in the real airplane before you see it in the simulator you got limited resolution on the joystick limited resolution you know on out the window and you're not going to see anything until it's already happened and so um i checked once i checked the mouth on the vertical speed i saw it was fine then my question was well what's this guy doing wrong with the joystick and i told him what i told you and uh and then i said i make it and he said well how do i do that exactly i said all right i'm gonna make a youtube video to explain it and see here goes what we want to do and we'll go and do this in in the other room in a moment is we want to set up a joystick response curve where if this is your input or how much you've deflected the joystick this is your output how much the elevator actually moves but i'll tell you what a reasonable default might be a straight line yeah 100 output here and just just to help just a little bit you know i can even say so basically if you pull back halfway you're getting a 50 elevator exactly and if you pull back 10 of the way yeah and ten percent elevator right because remember this is an aw this is kind of an old complaint of x plane right it's too sensitive that's the way it's always phrased what could a line look like to solve this problem to solve the problem that's what you want to solve on a saggy line saggy exactly this is a case where saggy is good okay a saggy line so here's what happens if your input is 50 what's your output yeah maybe like 20. exactly yeah put in 50 get out 20. put in a hundred you still get 100. yeah yeah but when you this this is your cruise you know your crew's elevator input well what is realistic are you compensating for his his lack of uh feel in his rear end when you do this so this is kind of making it not realistic in a way technically technically it's making it not realistic because you're not deflecting uh you're not getting as much response for a given stick deflection but here's a problem but it's also not realistic to not feel it in your butt exactly so we're compensating the lack of g-load which really gets your whole body i mean the g-load your whole body i mean your your cheeks everything the whole your whole body feels the acceleration and your body also feels the aircraft pitch up you feel that in the inner ear right so your inner ear is feeling the pitch up your body is feeling the g load the yoke has kind of a large deflection and a large resistance if you were to pull the oak all the way back at cruise speed in a cessna 172 which you should not do because you might over g the airplane and break the wings off and that would be a fatal accident but if you were to the force would be really really large um i bet you anything this guy's uh joystick it doesn't move as far as the yoke in a real skyhawk and it doesn't have the same resistance that a real skyhawk has in cruise so he's got a yoke where he's probably he's almost certainly deflecting it too much due to the yolk being smaller with a smaller control travel he doesn't have as much resistance so he's deflecting it farther he doesn't have his inner ear feeling the rotation of the airplane he doesn't have his whole body feeling the g-load and so lacking all this feedback what does he do he pulls the yoke back too far the airplane zooms up as a response and then what does he say the vertical speed indicator is too sensitive he's reporting what he sees because he's missing all this stuff that you're just not going to get in a simulator you know one thing that could be a good exercise to do if you're someone that's going between the real plane and the simulator is take a tape measure and fully deflect that yoke on that elevator axis in the plane and measure it see what your travel is right and then compare it to the travel on your actual device on your desk at home and and it's probably about half it's less and when you see it's less let's say that you get to the point that you're like oh crap my joystick and home only travels 50 percent the distance the the real airplane set your curve so that in in the cruise region you're only getting 50 percent of your reflection say a 50 input is a 25 output okay so here we are in the flight sim room and we're using what is this a yoko yoke mike yes okay um i gotta say my first blush is that the travel on this yolk is probably not that different from a cessna 172. it's longer than most okay yeah but the um the resistance feels like a 172 at maybe 45 knots or something you know half of cruise speed in other words in the cessna 172 and cruz just me much more resistance to the yoke and pitch up at cruise speed first of all have you ever seen this control sensitivity button down in joystick settings i have but i usually don't touch it okay probably most customers don't touch it fair enough so i'm gonna hit the control sensitivity button and you're zoomed in on it now the camera okay so let's take a look at the control sensitivity so we had we had asked what the default is the default is clearly fifty percent and by the way um each axis has a control sensitivity right correct patrol and yaw and so this button is just below each axis there's a little maybe you ought to do that one more time to show where that came from okay sure i'll do it again control sensitivity for any joystick you go here to control sensitivity i'm wiggling the mouse around down at the bottom there okay okay control sensitivity now look there's a little comment down at the bottom look when i am at control response at zero percent that's fully linear no find grain controls near center in other words a zero percent uh adjustment right this is the adjustment from linear when we're at a zero percent adjustment this is fully linear this is that graph that we started off with which is just a straight line right and then what you can do is say you know what i want to bring in some more sagginess you know sagginess of the line as you drag it notice how the comments change now at 100 it says maximum fine grained control near controls center so think of this as like the droopiness of the line now that said as we were going through this before you started the camera rolling i decided this is vague and annoying and it sucks and i'm going to delete it because it's garbage and so what we're going to do for the next generation of x-plane which i'm coding right now and very very close to showing to people we're not going to have this vague numerical interface that makes almost no sense to anyone it'll all be graphical and i'm going to code that probably later on today because it's just so obvious how inadequate this is however i'm still going to explain it on the youtube for people that are still flying x-plane 11 which won't be that much longer but for people who are still flying x11 while they're watching this uh they can they can see this and i won't explain the interface as it is so what we're going to do is we're going to start by putting this at fully linear so in other words if this yoke is deflected 25 the elevator will deflect 25 okay so this is just we're going to set this to full linear now now we're going to go so did you just make it more sensitive yes see i would think that would make it less sensitive when you go down to zero it's counteracting it's counter-intuitive okay i'm deleting the interface because it's counter-intuitive i'm gonna replace it with something that's visual and we're gonna replace it with something that tyler started and i don't quite like the way tyler implement tyler being guided to the user interface um tyler did something here that's way better than what i did he's got a visual response curve but i don't like the shape of his curves at all wow that sounds bad out of context but i don't like the shape of those joystick curves and so i'm going to improve uh them for next generation but um let's go ahead and look at something we can at least see ah does this look familiar after looking at our whiteboard now this this is where we can actually see where we're getting now when i look at this i see a curve that i absolutely hate right it's not smooth it's got an inflection point it comes up then it kind of goes down again for like no comprehensible reason i mean everything about this curve is absolutely terrible it looks like um the the global warming graph yeah so yeah yeah this this is yeah and here's when they invented the model t right it's like that but um i would like to come up with a much more smooth curve and i i will do it so uh for now if we want it to be linear we're going to basically do this and if you really want to be fine-grained you could do something like this and then what this would do is it would say okay when you were up to 75 input you should only get maybe a 15 or 20 output you see and so this would give you a much more uh but that's probably a little extreme right maybe and then what you could also do how do you think that's going to work well a few percent joystick input will go you know no no no comparison to a real airplane so so now that you understand how that works um what we're going to do we're in the cessna 172 here i'm going to step out of the room you you sneak in and do a setting now what about the other thing this control sensitivity shouldn't that be been the middle for this test or uh i'll tell you well i figured it would be linear because that way we're putting a linear input into that curve so basically if you're going to use a response curve you should probably set control response all the way to the left otherwise you're having two effects at the same time the first is the non-linear that i programmed back in like x-plane one yeah this is bad you all like did the same thing twice right and then tyler's you know exponential response curve that sits on top of that so they're both applied and it's it's one multiplied by the other gotcha so a little little confusing i'm gonna make it better um over the next like few days like before anyone even uh gets uh the next x-plane update this will be done but it's in the next uh the next gen matrix plan update um okay so i'm gonna sneak out of the room you do something behind my back tell me when to come in and then i'm gonna fly them to see if i can tell you what the setting is okay how the airplane feels all right i'm not even gonna cut here um you don't have to all right i'm out here all right let's see what can we do to the response curve so i'm not going to say what i'm going to do i'm just going to do it all right so hopefully you've got that all right and then i'm going to put us in the air on a 10 nautical mile approach okay austin okay come in yep come on in i stood away over by the air conditioner so i couldn't hear you if you were saying anything either okay so i'm gonna i just put us in the air and i just messed with the elevator axis of course oh whoa look how sensitive it is in roll maybe i must roll instead oh my gosh well i'm just barely touching this thing and rolling look i must have changed pitch is about right so i think that you so what's funny is i meant to change pitch but i can clearly change and not only that but i mean talk about cheating i can see it okay i love i love what you did there oh and by the way uh mark the customer that said the vsi was too sensitive he was using a regular cessna 172 not a g1000 so um you know you're just have to look at this little uh tape here um or what we could do to really be fair to mark is switch to a regular cessna 170 it has a visible you know vsi so we really see it yeah so i'll tell you what let's let's cancel using the g1000 let's go to a regular cessna 172 so we have the same airplane mark has okay and let's try it again and you try and confuse me and you try and punk me again and but you might have to do something different this time right because now i'm learning your tricks all right all right so i don't austin should not be able to hear me but i'm gonna i'm gonna talk kind of quietly so what i'm gonna do is i'm gonna do the opposite on the uh the roll i'm gonna give him a really weak roll response and then i'm gonna for pitch i'm gonna just go crazy and give him crazy sensitive pitch so his pitch is going to be very very sensitive and his roll very very unsensitive all right so now i'm going to pause not now this this has done a cruise so i'm going to give this thing all the power it's got okay this is very sensitive all right so let's you set the camera to see both the vertical speed indicator and my yoke can you set that yeah sure uh hold on just a second all right we're we're way in there now okay hit the up arrow on the keyboard a little bit what's that up arrow on the keyboard a little bit oh sorry down arrow down arrow okay whatever it's called okay okay so first of all it looks like you managed to get me to almost no role you see so i'm cheating like crazy here right the way the way to really the way to really you know stress me out is do this right so well i'm zoomed in i'm not seeing the scenery now i'm zoomed way in on these okay just make sure you can see the yolk and the instruments that's what you got to see so what i'm seeing here is extreme sensitivity and pitch i'm only moving the yoke uh maybe an eighth of an inch maybe a quarter of an inch and through an eighth or a quarter of an inch of displacement i am getting you know over 2000 feet per minute now some people this one will say says the 172's can't climb at 2 000 feet per minute i have people tell me briefly yeah of course they can briefly build up on i mean heck a car will do way more than 2 000 feet per minute run it off a jump like the duke's a hazard i mean anything can do 2 000 feet a minute you know a tennis ball a baseball throw it but um if you are in a cessna 172 and you yank the nose up of course it'll do 2 000 feet per minute for a moment but you'll be losing speed obviously so you've obviously had an extremely sensitive pitch here because the the the airplane is all over the place with now let's just show you you've done almost nothing and roll and now we can do is sure we can go down actually i prefer to do it this way and now what we see is i'm do you see both yolks the real yo the virtual yoke as you can see you set almost no response in roll oh until right until you cross over at that one boom and then in pitch okay so this is like a perfect job of like the worst possible airplane okay so i i'm still i bet i could still land it but i'm not gonna bore everybody by trying to do or maybe i couldn't i don't know um so you correctly guessed i cranked the sensitivity of the pitch okay and dialed way back on the roll okay so this is awesome so now now what okay now what i'm gonna do is i'm gonna do this i'm gonna set this to pitch okay that's your pitch so that as you put in a lot of pitch input you only get a little bit of output you're not going to fall off a cliff like you were doing just a second ago i mean right you went to a certain point all of a sudden 90 degrees so here it is it's i if you get very little up up to 75 you're only getting like a one in four or one and five input and then above 75 percent it says yeah we got to get some work done and then in roll roll is not really collect connecting oh that's pitch you were just doing now roll doesn't really have a uh a g load associated with it nearly so much and you can see the horizon you can really say so you don't really need this so much in roll so yeah but if you're somebody that's going oh my roll is too sensitive then okay put a little dry jacket down and i'm gonna i'm gonna edit these curves to be much much more smooth and nice math um so all right now let's say done all right now let's now let's see how this thing flies so first of all all right can you see both the physical and the virtual yo uh no sorry let me uh go ahead and set the camera turn that out okay you can see both yep okay so notice that it's kind of subtle in near the center it doesn't quite track and then really near the end it suddenly brings in you can see that can't you see it tracks it but not strongly then it really comes in and then for pitch it doesn't really move too much but then right in you know right near the end it really comes in whoa look at that that is you see but it's not really a whole lot you know in the center i mean i think i feel like i've overdone it here yeah probably overdone that a little bit overdone it a little bit so then what we'll do is go back to joystick and we're going to pitch and uh we're going to say all right i i went a little overboard you see we do that all right so let's go ahead and i'm just going to kind of establish uh establish some flight here and then let's say i'm told to go ahead and climb at 500 feet per minute you see i'm kind of easing back on the yoke a bit yeah look at that you see that the vertical speed it does lag a little bit just like the real airplane right if you aim for 500 you're going to get a little more than 500 because it takes a little while to catch up and the real vertical speed indicator does that as well and then as the speed bleeds off i have to pitch up more and more to hold 500 feet per minute right as the speed bleeds off to hold that fiber i have to keep raising the nose so as you see there's no wildly varying vertical speed i'm just missing the target you're overshooting a little bit simply because the the lag of the system all right let's try it again let's go ahead and see if i can level off here and i'll let the speed kind of build up a little bit if it wants to okay and notice i want a 500 per minute climb you see now i put in a little bit of yolk i feel like you know it's like it's kind of like driving a car on the highway it's a little bit of yoke pressure but not a large deflection and again i i keep aiming for 500 but going to 700 because it takes a little while for that vsi to to catch up and then i just feel like holding 700 that is so weird i think it's just because i'm looking for a climb attitude let's try that again let's see if third time is a charm so i'm flying along level and now i'm just going to ease sort of like oh and then the trick is to kind of ease off a little bit as you approach right before you get there as you approach 500 kind of ease off so it's like the first bit of deflection is getting the nose rotating up and then once you got that nose rotating up you kind of ease off a little bit you know as you're approaching you target ease off the yoke a little bit to then hold 500. and as you can see uh when you do this you're not in a situation where the vsi is you know wildly going all over the place but i still feel like my yoke deflections they felt just a little bit small i felt like i just had to be a little too careful because it took me a few tries to get it right and since it took me a few tries to get it right i'm going ahead and return it to a little a little more non-linear you see so i'm making that adjustment all right let's trim this thing out and in a way we encounter this when we fly all the time because we're holding altitude in a way the way i fly basically never encounter it at all because the autopilot is flying for this phase of flight and i never look at vertical speed i never think in terms of vertical speed i fly i always think in terms of speed angle of attack you know it doesn't matter what the vertical speed is the question is do i have the right climb speed and whatever you know vertical speed it gives me it gives me it's a climb speed that i want to fly and in the descent i want to stay within my speed limit so for me the vertical speed is always just that thing that winds up being whatever it needs to be to make everything else happy i never try and fly vertical speed but we're doing it just for this experiment all right let's go for 500 foot per minute climb again ah you see and this time with that that little bit of extra you know sagginess dialed into the curve i just eased a little bit of back pressure the thing comes on up towards 500 feet per minute as i start to approach my desired climb rate i ease off the stick just a little bit to stop rotating the nose upwards and now to hold it i'm just gradually gradually gradually having to add a little more back pressure because as the speed comes down i need more and more angle of attack to hold and frankly climb angle as well to hold this 500 uh foot per minute climb so i think the flight model is behaving absolutely uh perfectly and when people say oh the vertical speed indicator is too sensitive or the airplane is too sensitive in pitch they just haven't figured out this whole uh non-linear uh and again the shorter the throw on your physical yoke the worst thing in your hand the worse the problem is that yoko has a very long uh elevator axis on it but if you're using let's say a logitech which is like right over here it has a very short uh elevator axis so it's going to be very sensitive and it's got that hard detent in the middle so all right let's do this the longer the better let's try one more thing let's let me try a quick landing and i'll just land on a road here to save everybody some time rather than looking for an airport let's try a quick landing and see how this thing feels uh for the landing where you actually do need um a significant amount of uh joystick playing in the field terrorize people on this road over here to the right and the whole airplane this non-linear joystick the whole airplane just feels heavier it doesn't feel you see you see how it's just stable it's just holding it's just holding its uh approach here it's just so stable it just feels like the whole airplane weighs uh more which is so much more stable just feels like an airplane now all right so then i'm kind of easing back see now i'm starting to feel a little back pressure just ignoring them yeah watch the car oh that feels just like a real plane oh that's beautiful you see and now i'm finally getting that joystick in but i should probably use a rudder shouldn't i now i'm finally getting that uh i should have put my feet on the rudder so i would not look like your feet are not on the rudder yeah my feet are actually on the pedals because i'm lazy but um see then maybe i can raise yeah and by the way we should mention people that think the rudder pedals are too sensitive the same thing yeah safety applies to rudder so yeah that felt just like landing a real airplane there so um i think i we've proven with math that the altitude tracks the uh vertical speed um where the the video that mark sent showed about a 50-foot change for doing a thousand foot per minute for three seconds and uh we've shown how this airplane can be made to feel just like a real airplane a little bit of a joystick adjustment uh our joystick you know response curve adjustment and um and i would say the response curve is different depending on what kind of controller you have the shorter the throw on the elevator axis the droopier it needs to be that curve needs to be because otherwise the small joystick deflections go woo wouldn't send you out to crazy g-load

Channel: Michael Brown

Views: 2,323

Rating: 5 out of 5

Keywords: X-Plane, XForcePC, Controller Setup

Id: u-YxxAUgsxg

Length: 27min 25sec (1645 seconds)

Published: Sun Sep 12 2021