So proportional navigation depends on keeping the angular acceleration of the missiles flight path proportional to the angular rate of the line of sight angle of the target, and thus the missile ideally only takes acceleration commands. The trouble I had for the longest time was how do I make a missile hold a certain angle (in this case pitch angle) using acceleration commands.
As for the science of lofting it is exactly as I described in the description. Let me know what else I can clarify.
@Warwolf182 basically you are going to go to your plane and make the variable menu have the exact same things as the variable menu of the pod when you first download it. So copy the name (left side of the variable box) and the expression (right side of the box) from the pod, then go to your plane, and copy in the name and the expression.
Simpleplanes gives you the very very basic to work with and there’s not a lot of shortcuts to working from only the foundation. Take a look at my codes (I highly suggest any missile but this one) and see if you can make sense of it and implement it on your own missile.
@Object775blyat You have to open Overload on the part and its gonna be part of the engine's XML properties. You add it to the same page as the power multiplier and exhaust color override.
@Object775blyat In the engine properties your gonna add a new property called "throttleResponse" and set that to whatever. The higher the number the faster the engine spools up.
@QuesoAirlines So the reason it did that is not necessarily because you clicked it, but you double clicked to open the modify menu. The degree range on the rotator is precisely 1 degrees, and if you open the default part editor (the menu that comes on on the left side of the screen) the game won't be able to process that I only want it to turn 1 degree and so it makes the range 0 degrees, which is free spin.
To properly fix that you should've opened fine tuner and change the range back to 1 degree and speed back to 1.
@kismit Well done on the success of your build. We may have talked about this before already but my offer to mount funky trees weapons to your build instead of default missiles still stands; you know where to find me.
@CACHA That highly depends on how the rest of your plane is built. You could potentially turn whatever you want to measure onto it's butt and measure the drag force when the entire belly of the plane is headed into the wing (aoa of 90 degrees) and the correlation of aoa and drag force should be roughly linear.
To answer your question better,
Funky Trees is essentially a coding language unique to SimplePlanes and essential to programming your plane to do more than the bare, default, minimum.
A Funky Trees MIssile is essentially re-inventing the wheel in terms of practicality, since the in game default missiles are a lot more easily customizable, consistent, and easy to use. However, there is joy for the small number of us to take advantage of the game's physics engine to test our engineering abilities.
@Magma1358 Hi,
Essentially, there's two parts in creating a funky trees missile: making a stable and good performing missile, and then making an auto pilot that tracks a target. I would recommend starting with the first task, then researching how to do the latter. Please see some of my other posts where I explain more in depth in the comments.
@SuperSuperTheSylph Good work on the missile, however I have a couple feedback based on my own experience with FT missile
1. The symmetrical airfoil wings stall past 13 degrees of aoa, so there's usually no point in deflecting the fins past like 10 degrees; this will almost always give you the best maneuverability
2. The guidance is very rudimentary and tbh very inaccurate. I would recommend you to look into the kinematic equation in radial coordinates, aka what automatic turrets also use for lead/aim. If you want to take it one step further, I recommend you to look up proportional guidance in the context of missile guidance design.
That being said, this is a big step for you and I remember taking steps like these 2 years ago.
@Quercon and yes i have considered using coordinate transfers but those are extremely tedious to code and is simply not worth it for this type of build. Perhaps it would be worth it for future ballistic missile builds though.
@Quercon PID is a very simple and flexible tool and how to calibrate it depends on your understanding of what the I and D term does. The I term is used if you have consistent undershoot that can not be corrected with P over time, and D is used for dampening oscillations and preventing overshoots. What i used in this missile specifically is called proportional guidance, and it guides by controlling the angular acceleration of the missile , and so it oscillates a lot, thus i have a D term. Feel free to go into the code and mess with it to see what i’m talking abt.
@waylaymythz someone already beat me to it. I think someone made an ultimate countermeasure to all missiles in game and it was posted like a month ago. It works well against my missiles to and I recommend u checking it out.
@UltravioletBlood a lot of trial and error. Make sure both the bomb and the fuselage section you intend for it to smash into have collision enabled, and it's just a matter of finding how far the bomb needs to be from the fuselage, how fast/far the piston needs to extend to squeeze the bomb to make it blow up, etc.
@llDeadboyll It depends but generally, there's always a way around it. Although it is always better to take the extra time to cover all of your bases.
If it is a conventional plane then an autopilot can totally ignore angle of attack/slip values. If it is something PSM capable (intentional or not) then you definitely need to take care of AOA and make sure you don't stall yourself when you don't want to.
@llDeadboyll Assuming you are asking me if it is possible to make a missile autopilot without taking into account of Angle Of Attack and Angle Of Slip; Yes, I do it without those values all the time, especially for multi-firing or aircraft mounted missiles since a flight computer that's not set as the primary cockpit does not return values of angle of attack/slip and calculating them is a hassle and adds more variables that you have to transfer and more points for failure/inconsistency.
@ThomasRoderick no this finding is indeed based on wetted area of an object, because i tested this with only fuselage blocks. In addition, wings do not change the drag value the game displays to you. This is pure parasite drag. The total parasite drag must be found and added up with the wing profile drag and induced drag, then be non-dimensionalised by dividing it with dynamic pressure and wing area, giving you the overall drag coefficient of the aircraft.
Looking back I also realized that the game seems to already take into account the wetted area of objects when it spits you the drag value, since in all my testing, even with different geometries, the value of 0.0010145 was consistent.
Thus the in game drag value is not the drag coefficient, rather the Drag coefficient times wetted area. The proper drag force experienced by your aircraft can still be calculated with the original equation in post.
@ThomasRoderick mk i thought abt it a little more
You are right in that the Drag is proportional to wetted area. Then the parasite drag force felt by the whole aircraft equation should be
‘D=ACd0.5rhov^2’
You are also right in the Cd is indeed dimensionless, so units on both side of the question must cancel out. The only way that would happen is if the equation is arranged as above (Force cancels Force, remember that the right side of the equation is basically dynamic pressure times area = force)
@ThomasRoderick The Coefficient of drag is indeed proportional to the wetted area of the plane. D in my equation is the drag Force felt by the airplane, which increases with airspeed
@Graingy
1. Drag coefficient is a non-dimensionalized coefficient to measure and compare drag. Aka it is independent of speed/altitude and thus u can directly compare this value between planes and designs
2. To my knowledge air density is modeled using an ideal standard day scenario and yes it decreases as u get higher in altitude
3. Yes air density affects jet engine performance heavily in simpleplanes. However I am not sure about how it affects prop engines.
4. Yes u would multiply the drag scale of the wing.
5. I don’t know what kind of scale would be realistic for the wing just yet cause i haven’t tested that. In addition drag produced by the wing IRL is heavily dependent on it’s shape and may differ wildly even at the same surface area.
6. Yes u can search it up in reference to an existing aircraft. You would want to search up Parasite drag coefficient and the symbol you should be looking for is Cd0. Then use the formula/relations above to find the in game drag value u should be shooting for.
Ladies and Gentlemen, I am very aware of the difficulties of using the targeting computer on mobile, specifically that the knobs are really hard to grab hold of. I do not have a solution for this other than to recommend you to play it on PC. This will be accounted for for my next project. I apologize for the inconvenience.
I sincerely appreciate all of your support despite the technical difficulties.
@llDeadboyll I suppose it was from a lack of understanding of how Ballistic missiles work and my general bias against anything to do with space at the time. I’ve since read some technical books and grew an interest in Ballistic Missiles, so I started to learn how they work and I started to tinker… and here we are 3 months later
@TritonAerospace sure
So proportional navigation depends on keeping the angular acceleration of the missiles flight path proportional to the angular rate of the line of sight angle of the target, and thus the missile ideally only takes acceleration commands. The trouble I had for the longest time was how do I make a missile hold a certain angle (in this case pitch angle) using acceleration commands.
As for the science of lofting it is exactly as I described in the description. Let me know what else I can clarify.
@TritonAerospace expand on that…
@AtlasMilitaryIndustries yes it’ll be alright. Ur always free to use anything so long as u credit me.
@Warwolf182 basically you are going to go to your plane and make the variable menu have the exact same things as the variable menu of the pod when you first download it. So copy the name (left side of the variable box) and the expression (right side of the box) from the pod, then go to your plane, and copy in the name and the expression.
@Rb2h lmao there isn’t
Simpleplanes gives you the very very basic to work with and there’s not a lot of shortcuts to working from only the foundation. Take a look at my codes (I highly suggest any missile but this one) and see if you can make sense of it and implement it on your own missile.
+1@JJmaca please reference my other posts on how to attach ft missiles to your plane. Its not as simple as drag and drop.
@Object775blyat whatever you want. 1 is default value and 2 would mean it spools up twice as fast and so on.
@Object775blyat You have to open Overload on the part and its gonna be part of the engine's XML properties. You add it to the same page as the power multiplier and exhaust color override.
@Object775blyat In the engine properties your gonna add a new property called "throttleResponse" and set that to whatever. The higher the number the faster the engine spools up.
Goated game of all time
+1@Thatmililitaryguy u must’ve accidentally not copied the entire variable expression. Try copying it again
@Thatmililitaryguy What do u mean by variable stack?
@kpfpz70m933 ya use it however u want
@QuesoAirlines or just dont double click the part and open its editor menu at all when moving it to avoid this problem
@QuesoAirlines So the reason it did that is not necessarily because you clicked it, but you double clicked to open the modify menu. The degree range on the rotator is precisely 1 degrees, and if you open the default part editor (the menu that comes on on the left side of the screen) the game won't be able to process that I only want it to turn 1 degree and so it makes the range 0 degrees, which is free spin.
To properly fix that you should've opened fine tuner and change the range back to 1 degree and speed back to 1.
@Yourlocalhuman no
@kismit Well done on the success of your build. We may have talked about this before already but my offer to mount funky trees weapons to your build instead of default missiles still stands; you know where to find me.
@CACHA That highly depends on how the rest of your plane is built. You could potentially turn whatever you want to measure onto it's butt and measure the drag force when the entire belly of the plane is headed into the wing (aoa of 90 degrees) and the correlation of aoa and drag force should be roughly linear.
@ThomasRoderick yes
+1To answer your question better,
Funky Trees is essentially a coding language unique to SimplePlanes and essential to programming your plane to do more than the bare, default, minimum.
A Funky Trees MIssile is essentially re-inventing the wheel in terms of practicality, since the in game default missiles are a lot more easily customizable, consistent, and easy to use. However, there is joy for the small number of us to take advantage of the game's physics engine to test our engineering abilities.
@Magma1358 Hi,
+1Essentially, there's two parts in creating a funky trees missile: making a stable and good performing missile, and then making an auto pilot that tracks a target. I would recommend starting with the first task, then researching how to do the latter. Please see some of my other posts where I explain more in depth in the comments.
@RicardoACE you have a discord?
@SuperSuperTheSylph oh my bad lol
+1@SuperSuperTheSylph Good work on the missile, however I have a couple feedback based on my own experience with FT missile
1. The symmetrical airfoil wings stall past 13 degrees of aoa, so there's usually no point in deflecting the fins past like 10 degrees; this will almost always give you the best maneuverability
2. The guidance is very rudimentary and tbh very inaccurate. I would recommend you to look into the kinematic equation in radial coordinates, aka what automatic turrets also use for lead/aim. If you want to take it one step further, I recommend you to look up proportional guidance in the context of missile guidance design.
That being said, this is a big step for you and I remember taking steps like these 2 years ago.
pretty much on track to making ur very own FT missiles
+2@waylaymythz Ofc
+1@Unitedareospace21 Ok what do u need it to do
@Unitedareospace21 Alright what would u like help with on it
@Quercon and yes i have considered using coordinate transfers but those are extremely tedious to code and is simply not worth it for this type of build. Perhaps it would be worth it for future ballistic missile builds though.
@Quercon PID is a very simple and flexible tool and how to calibrate it depends on your understanding of what the I and D term does. The I term is used if you have consistent undershoot that can not be corrected with P over time, and D is used for dampening oscillations and preventing overshoots. What i used in this missile specifically is called proportional guidance, and it guides by controlling the angular acceleration of the missile , and so it oscillates a lot, thus i have a D term. Feel free to go into the code and mess with it to see what i’m talking abt.
@Monarchii Very nice flying heli. Would I have permission to turn this into another AI Heli?
@Unitedareospace21 Upload whatever you are trying to work on as unlisted and gimme the link. We can talk in the comments there.
@Unitedareospace21 Yes. Reach out to me on discord @kuatta4
@Unitedareospace21 What specifically would you like help on?
@waylaymythz someone already beat me to it. I think someone made an ultimate countermeasure to all missiles in game and it was posted like a month ago. It works well against my missiles to and I recommend u checking it out.
+1@UltravioletBlood a lot of trial and error. Make sure both the bomb and the fuselage section you intend for it to smash into have collision enabled, and it's just a matter of finding how far the bomb needs to be from the fuselage, how fast/far the piston needs to extend to squeeze the bomb to make it blow up, etc.
+1@MosquitowithaMachineGun Weather mod by MisterT. You can use one of the lower cloud settings in combination with Simpleplane's default sky box.
+3@llDeadboyll It depends but generally, there's always a way around it. Although it is always better to take the extra time to cover all of your bases.
If it is a conventional plane then an autopilot can totally ignore angle of attack/slip values. If it is something PSM capable (intentional or not) then you definitely need to take care of AOA and make sure you don't stall yourself when you don't want to.
@llDeadboyll Assuming you are asking me if it is possible to make a missile autopilot without taking into account of Angle Of Attack and Angle Of Slip; Yes, I do it without those values all the time, especially for multi-firing or aircraft mounted missiles since a flight computer that's not set as the primary cockpit does not return values of angle of attack/slip and calculating them is a hassle and adds more variables that you have to transfer and more points for failure/inconsistency.
@KmanSP Surface to Air Missile
@Monarchii Where is it?
@ThomasRoderick no this finding is indeed based on wetted area of an object, because i tested this with only fuselage blocks. In addition, wings do not change the drag value the game displays to you. This is pure parasite drag. The total parasite drag must be found and added up with the wing profile drag and induced drag, then be non-dimensionalised by dividing it with dynamic pressure and wing area, giving you the overall drag coefficient of the aircraft.
+1@XEPOH It in fact, to some degree, does; it’s how physics work.
What kind of satisfactory result r u looking for?
+1Looking back I also realized that the game seems to already take into account the wetted area of objects when it spits you the drag value, since in all my testing, even with different geometries, the value of 0.0010145 was consistent.
Thus the in game drag value is not the drag coefficient, rather the Drag coefficient times wetted area. The proper drag force experienced by your aircraft can still be calculated with the original equation in post.
@ThomasRoderick mk i thought abt it a little more
You are right in that the Drag is proportional to wetted area. Then the parasite drag force felt by the whole aircraft equation should be
‘D=ACd0.5rhov^2’
You are also right in the Cd is indeed dimensionless, so units on both side of the question must cancel out. The only way that would happen is if the equation is arranged as above (Force cancels Force, remember that the right side of the equation is basically dynamic pressure times area = force)
@Ashdenpaw1 This was a known problem, as stated in the description.
+1@ThomasRoderick The Coefficient of drag is indeed proportional to the wetted area of the plane. D in my equation is the drag Force felt by the airplane, which increases with airspeed
@Graingy
1. Drag coefficient is a non-dimensionalized coefficient to measure and compare drag. Aka it is independent of speed/altitude and thus u can directly compare this value between planes and designs
2. To my knowledge air density is modeled using an ideal standard day scenario and yes it decreases as u get higher in altitude
3. Yes air density affects jet engine performance heavily in simpleplanes. However I am not sure about how it affects prop engines.
4. Yes u would multiply the drag scale of the wing.
5. I don’t know what kind of scale would be realistic for the wing just yet cause i haven’t tested that. In addition drag produced by the wing IRL is heavily dependent on it’s shape and may differ wildly even at the same surface area.
6. Yes u can search it up in reference to an existing aircraft. You would want to search up Parasite drag coefficient and the symbol you should be looking for is Cd0. Then use the formula/relations above to find the in game drag value u should be shooting for.
Ladies and Gentlemen, I am very aware of the difficulties of using the targeting computer on mobile, specifically that the knobs are really hard to grab hold of. I do not have a solution for this other than to recommend you to play it on PC. This will be accounted for for my next project. I apologize for the inconvenience.
I sincerely appreciate all of your support despite the technical difficulties.
@llDeadboyll I suppose it was from a lack of understanding of how Ballistic missiles work and my general bias against anything to do with space at the time. I’ve since read some technical books and grew an interest in Ballistic Missiles, so I started to learn how they work and I started to tinker… and here we are 3 months later