Even if there was, the ingame stat is “Max” g-load. The fact theyre using what they believe to be the “average” g-load as the max is immediately silly, particularly when weve seen them set fin aoa’s to adjust at what kinds of speeds the missile can actually reach those peak G loads…
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It’s difficult to confirm the effective control surface area between the two missiles, but there are vastly higher performance weapons of similar size and mass with rolling airframe control type. Mistral, for one, is in the same weight class but turns much harder.
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june 7th and nothing has changed
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It’s joever
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Considering what I just found, i doubt it. and it at very least refutes that the Igla and Stinger work the same way.
This is an excerpt from DMs with a few Techmods
Sources used are
The FIM-43’s Rolling Airframe Control Schema
https://patents.google.com/patent/US3010677A
The Improved Rolling Airframe Control Schema (directly references , and claims improvement over the above methods, as well as sharing characteristics of the FIM-92 airframe, not the RIM-116)
A Rolling airframe (with Dithering control surfaces) Autopilot implementation
(There is a 4th patent that deals with maintaining the Roll rate using the fixed surfaces, but until I get there its not yet directly relevant past a point, as a difference from counterparts)
The Three technical papers (for further reading at this point)
An Aerodynamic Analysis of a Spinning Missile with Dithering Canards
Control of Spinning Symmetric Airframes
AERODYNAMICS OF A ROLLING AIRFRAME MISSILE
I’ll address the issue(s) with the MANPADS article, of which a number or inaccuracies have been discovered. Of which I’ll run through things in a revised order to make more sense, and highlight the differences between the system’s (Redeye, Igla, Stinger) features as there are subtle, but critical to their performance and differences that the not mentioned.
Scope & Claims of the Article
In this, Figure 9.(specifically the Shaded area of “Fz”)and excerpts of US3010677. and the below Passage from the article are in good agreement. Though note with Figure 12., the fact that the Redeye (like the earlier Strela-2) lack a second set of pop-out surfaces, as found on the Igla (The Stinger has a similar system, but it’s a little more advanced)which influence the aerodynamic Center of Lift of the missile forward, closer to the center of mass, and so reduces the effective moment arm and resultant longitudinal inertia of the system making it more maneuverable than said system.
US3010677 exerpts
Consequently, the wings are extended for a portion of. each roll cycle; the center of the extension periods coincides with the desired direction of lift, and the width of the period is a function of the error signal magnitude. This wing extended time is called the lift sector. The desired-direction lift and quadrature lift which result are also shown in FIGURE 9.
( Note; Quadrature is used due to the rolling frame of reference, a synonym would be Orthogonal, Yaw or Axial in other reference frames)
Actually, the lift force generated by the wings is only a fraction of the required lift force. The remainder of the force is provided by the fuselage; Since body angle of attack lags behind wing force in time, the reference coil must be rotated through a lag angle with respect to the wings. This lag angle is such that the net lift force (wing plus body) is in the direction of the target.
The way the resulting force in the missile maneuver plane changes can be represented in a simplified form as a half-wave of a sine wave. The average resulting force in the maneuver plane over a half-period of rotation is equal to the integral of the change of the resultant force in the maneuver plane. Dividing it by the integral of the resulting force in the plane of the maneuver of a non-rolling airframe missile over the same time period, we obtain the ratio of maximum overload to the average overload over the rotation period.
Therefore, the average resulting force over half a rotation period for a missile with a single-channel control system in relay mode will be 63.66% compared to the same non-rotating missile performing a maneuver in the plane of the control surfaces. The ratio is also the same for the average available overload to the peak one when the rudders are in the maneuver plane.
If that’s how the Igla works, in a similar manner to the FIM-43 that’s fine model it as such, no issues there.
This is where the Article effectively entirely drops the ball and runs entirely on assumptions and conflates systems and features since they’re not outwardly obvious.
The points of order are that;
-
The stinger uses Variable Incidence (proportional) control surfaces, not of the Bang Bang type the Igla uses
-
The Stinger uses a Closed loop guidance method, which is capable of damping control responses and so fundamentally can account for reduced stability of a design.
Take any one of the excerpts below, its fairly obvious that the Stinger could not function if it was similarly equipt to the Igla with Bang-Bang control surfaces
US4037806 exerpts
prior to the invention set forth in the hereinafter cited co-opening application, control of a rolling missile was effected by utilizing fixed incidence, variable area canards or wings which were extended into the missile air stream at a certain point in the revolution of the missile, as described and claimed in U.S. Pat. # 3010677
~~
However, this invention provides an air vehicle such as a missile with a pair of fixed wings or canards and a pair of variable incidence control surfaces or canards which are continuously dithered or vibrated so as to provide instantaneous movement due to the elimination of the initial inertial force.
~~
In the servosystem of the present invention, missile wing incidence is controlled by a non-linear control servo loop and comprises a position servo having non linear switching elements in the forward loop. The wing position output follows control-servo command input voltages, which vary sinusoidally at the missile roll frequency for steady tracking rates. The servo error signal, which is the difference between the control servo command and the wing position feedback signals, is superimposed on a dither oscillator signal, causing the servo switching circuit to pulse modulate power to a torque motor. The torque motor integrates this incoming pulse-modulated signal so that the resultant wing deflection rate follows the servo error signal. Therefore, an object of this invention is to provide a control system for air vehicles. A further object of the invention is to provide a missile servocontrol system which utilizes variable incidence control surfaces.
~~
The seeker proportional navigation signals, processed by the missile control section, command control surface movements so that the missile trajectory becomes a collision course with the target. When a maneuver is called for, the angle of the variable-incidence control surfaces is changed as required for flight path correction.
~~
Connected with said dithering means whereby the incidence angle of the variable incidence control surfaces is selectively varied during that portion of the missile’s roll necessary to keep the missile on a target intercept course while continuously dithering said control surfaces course.
With a single-channel relay control of a rolling airframe missile, to create a control force in any direction of flight, the rudders are moved by the servomotor mechanism from one outermost position to another four times per revolution of the missile’s rotation. This rudder control scheme makes it possible to regulate the resulting overload and therefore ensure proportional guidance of the missile.
For other MANPADS systems, open sources indicate a higher overload such as 18, 20 and even 25g in the case of the Mistral 1 MANPADS. However, these MANPADS systems have only slight differences in the area of aerodynamic surfaces compared to the 9M39, so a multiple increase in average achievable overload compared to the 9M39 cannot be expected.
Let alone US4054254 which describes the requirement of an open loop control schema (no feedback loop in the guidance section), to use a more aerodynamic design with greater stability (Center of lift behind of center of mass), than that of a similar closed loop design. This is important due to the fact that a Stable design must first overcome the restoring forces inherently generated to achieve a given angle of attack, And that an Open loop configuration is inherently conservative due to not being able to account for other factors and so the design needs to take edge cases into account, where the performance can be optimized by using a Closed loop design.
It is observable that the FIM-92 uses a Closed loop schema, as the Feedback Network is a clearly listed element in Figure. 4, (Block diagram) of US4037806 ,as seen above)) though the example missile in US4054254 is that of a RIM-116 (same Contractor involved with both in the same timeframe).
Also noteworthy is that Figures. 6c & -d(see below for excerpts), do not agree with the modeling (“Fz” & “Fx”) and so should not be impacted by the averaging of performance limits , as asserted in the MANPADS article.
US4054254 excerpts
The systems utilized are designated open-loop in that they utilize a control demand that is not modified by feed-back
So now that It has been asserted to be erroneous, what do we do?
Simply reinstate the limits as per primary sources at about 18~22G as they were, when originally implemented; in 1.91.
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Oh people. You are making trouble here and wasting your life.
The snail has decided that the Stinger will pull 13g.
It doesn’t matter what is found in documents. It is interpreted to suit the snail.
End of story, nothing to add.
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Well if enough attention is drawn to it, they won’t be able to pretend it doesn’t exist and need to at least come up with a reason it shouldn’t apply.
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Well, now you need to pass it to Gaijin and see what they will do. Either via a bug report or for example Smin ping.
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I guess I could, it’s just that the bug report portal isn’t exactly the easiest to manipulate for something like this, with many excerpts, figures & sources.
and keeping the rest of the forums aware will be key so it can’t be buried.
Also obligatory;
Please check your DMs, its been a few days.
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Wow. That’s quite the write-up, and presented in a manner that’s (mostly) intelligible by laymen like me.
Best of luck with the report 👍
Oh, I’ve also got one for extending the lock-on range of the POST seeker (MIM-72G & FIM-92B and later variants including the yet to be implemented later ATAS) via the (Photo)contrast Lock-on range extension mechanic.
This would be based off the wording used in US4009393, repeatedly and specifically using the term contrast (relevant excerpts below), and the Block diagram(Figure .6), making it fairly obvious that both the IR and UV channels are used simultaneously; summed into a single output which is passed onto the Guidance and Control stages of the missile.
This is basically open and Shut in this case; and would be a reopening / extension of the following report;
https://community.gaijin.net/issues/p/warthunder/i/3Ktqrit8Rqfx
I’d accept that with the existing implementation it would lack the ability to automatically swap between guidance modes in flight, as a balancing decision, on the dev’s part.
Seeker patent and ATAS excerpts
The UV lens 104 should function in a narrow wave
length band in the near UV for best contrast results~~
The peak detectors measure the amplitude of the highest contrasting object within the field of view and the resulting peak levels are used to set the thresholds of the threshold detectors. The information from the threshold detectors is coupled to logic selector 148 which selects the proper mode for target tracking. The logic involved in the logic selector circuit is such that, if the signals from both the IR and UV channels are simultaneously present at its input, the IR signal will be preferred over the UV signal. However, should the IR signal vanish for a time longer than 0.25 second, the UV signal will be accepted.~~
As described, the target tracking seeker of the present invention includes both IR and UV seeker elements. Accordingly, where a target may not be irradiating sufficient infrared energy to be engaged by the missile operating in its normal IR mode, the target may be tracked by the UV mode. The missile electronics can select the mode offering the best tracking information and are capable of switching from one mode to the other. As a result, cold targets or head-on targets can be successfully tracked. Also, countermeasures against one mode will not normally affect the operation of the other mode. In addition, discrimination against multiple targets and decoys with improved range and with a higher degree of background rejection achieved. Targets which are clearly visible are detectable by a seeker operating in a visible UV mode regardless of IR target energy.The detected signal may be negative (a non-radiating target seen against a bright background) or positive (a radiating or reflecting target seen against a dark background). Preferably, the seeker will initially operate in the visual contrast mode until an adequate IR signal is available to home the missile. If a sufficiently IR radiating target is present, the seeker may select and receive in the IR mode.
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More chance of getting blood from a stone than gaijin doing anything positive for spaa players
I don’t think they would say no considering how many nations are stuck with the impacted missiles (Italy / Israel).
The Maneuverability report is Live.
Hit the character limit on the submission, lol.
https://community.gaijin.net/issues/p/warthunder/i/yUohrEMuQLna
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I’m at least going to assume that it was in good faith, just a lack of specific info at least in this case(for now).
The POST seeker report is up
https://community.gaijin.net/issues/p/warthunder/i/LbD7XSmoaAJc
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Hope this goes somewhere given the stinger is still abysmal, but given the past situations with the stingers I am not holding my breath.
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I hope so, too. Because the armament on the Type 93 failed spectacularly the other day when I was using it. Many launches on easy targets and the missiles either pissed off in a straight direction or just outright forgot how to lead properly.
Absolutely piss-poor state of affairs.
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The more people that know about both reports the more likely that something will get done, if it can be spread to as many Content Creators, Discord servers, reddit the better. Since more eyes will be on Gaijin’s response.
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Make sure to put it on the MANPAD thread too:
1 Like