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  1. [41]
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    تاريخ التسجيل: May 2006
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    وسام الشكر

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    لا افتيك في هذا يا صديقي ,,,, و لكن هناك نظام التعليم المفتوح الذي تطبقه جامعة القاهرة ,,,, ربما يمكنك ان تدرس هندسة الطيران ضمن هذا البرنامج,,,,, انصحك ان تعرج علي جامعة القاهرة و تستشير المختصين ,,,,
    و عموما بريدي الالكتروني علي ****** هو Engmbadr و اي خدمه

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  2. [42]
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    وسام الشكر

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    و بما انك يا صديقي رجل برمجه سأهدي لك هذا
    Rocket Guidance
    We came to the point where we needed to know about rocket guidance.
    The best two books we found on the subject are "Guided Weapon Control
    Systems" by Paul Garnell, 1980. (A good book, but out of print. See a
    college or university library. If they don't have it, get an inter-library
    loan.) And "Tactical & Strategic Missile Guidance", 1990 by Paul Zarchan.
    He has some FORTRAN programs that can be rewritten into BASIC, and the book
    is very readable. Chapter two is most applicable to small rockets. Chapter
    nine is also useful. It's helpful to read these two books together if
    possible. In a library these are found as: UG 1310.(author's initial) (35
    or 37) (year), Library of Congress system. Also good is the article
    "Sidewinder" in "Invention and Technology" magazine, Fall 1989, pp. 56-63.
    In the library you may also see "Radar Homing Guidance for Tactical
    Missiles" by James. Some pages were useful. "Automatic Control of
    Aircraft and Missiles" by Blakelock, is about autopilots. Very scholarly.
    The newest book we've found (1991) is "Modern Navig., Guid. and Control
    Processing" by Ching-Fang Lin, which is still in print.
    To help you appreciate rocket guidance, just imagine you're running
    at a right angle to get on a moving bus which has its door open. There
    are basically four methods of getting to the door. (1) You could simply
    run straight toward the door at all times as it moves. (2) You could run
    at a fixed course that depends on the your speed and some initial sightline
    angle. (3) You could lead by a changing angle that depends on your speed
    and the bus' angular speed. (proportional navigation) (4) You could run at
    some constant sighting angle to the door at all times (demand angle of
    sight). Some of these strategies work more efficiently than others, but
    might be impractical to implement in an amateur rocket.
    Sighting on the door, your sightline swings at some angular speed.
    Proportional navigation means that your running-path rotation rate is
    faster than the sightline rotation rate by some constant multiplier. So
    eventually your path will be "correct" and your sightline angle won't
    change. Now you are on a perfect intercept course. The higher the
    multiplier number, the faster you correct your path early in the flight
    and the less correction is needed later in the flight.
    This multiplier number is called the navigation constant. By the way,
    if it is 1, you're just running straight at the door. This choice is
    simple to implement, but it's a poor choice when you get close to the
    door, because the bus may go faster than you can run! And as you get very
    close, the bus may change speed or direction.
    Steering a rocket using proportional navigation depends on three factors.
    The sideways or lateral acceleration, called latax, given to the rocket
    must be the product of: (1) the navigation constant times (2) the closing
    velocity times (3) the target sightline rotation rate. Sounds simple
    enough. The difficulty comes from how you measure the last one, how you
    measure the rocket's true orientation and motion rates in space
    and how you implement the control motions.
    The multiplier number is always 1 or higher and the closing speed
    can't be zero if you want to have intercept, so let's look at the last
    factor. This is the one you want to have be zero, which means that
    you're on a collision course and you now need no further correction.
    Approaching impact, the target always appears to be at the SAME angle.
    Early ship captains knew that this was a sure sign a collision at sea
    was about happen, and which would ruin their whole day!
    An interesting curiosity regarding the perfect initial lead angle is
    that if your rocket has the same vertical speed as the target's constant
    horizontal speed during its entire flight and the target flies straight,
    you need only to launch at exactly as many degrees ahead of the target as
    the target is seen in degrees above the horizon at the instant of launch.
    If the navigation constant is 2, the sightline angle is always constant
    and the rocket will move in a circle. (The angle you use is dependent on
    closing speed.) The navigation constant ideally is 3, needing the least
    correction over the entire flight. In reality it varies from 2 to 5,
    depending on the motions of the target and the rocket. The navigation
    constant depends roughly on the area of the fins and the fin swing angle.
    This can be measured in a wind tunnel.
    The closing velocity is how fast the rocket and target come together.
    But if we're only hitting a towed kite or bunch of balloons, the closing
    velocity is the vertical velocity. You can find this speed using a BASIC
    rocket flight dynamics program, providing you know your individual rocket's
    true parameters. Or you can track it using a camera-theodolite.
    How do we account for the sightline swing? We don't. An operator
    watches a TV monitor and controls sightline angle. A concentric circle
    representing the chosen angle is marked on the screen. The operator is to
    keep the target on the circle (not centered) with it's flight direction
    passing thru the center of the screen. Automatic roll control is a must,
    by using the sun's position or a good model-helo gyro.
    Latax is produced by aerodynamic forces acting on control surfaces.
    This force increases with speed if fins are rigid. Twice the speed means
    four times the force! We could keep this force proportional to fin angle
    by keeping the speed constant. But a better way is by making the force
    independent of speed. You can do this simply by spring-loading the
    control surfaces, like the Sidewinder's. Measure the side force on the
    rocket in the wind tunnel. Choose the spring stiffness such that the
    servo angle is proportional to the latax force at different wind speeds.
    This way the same joystick motion gives the same control force.
    In the wind tunnel, the air speed is the "closing speed" in the case of
    flying up to hit a target. Getting technical, the control surfaces put a
    force on the rocket. This is ahead of the CG and even farther ahead of
    the CP. This torque accelerates the rotation like a weathervane around
    the CP, at a rate that depends on the torque divided by the moment of
    inertia. Whatever.
    The main thing is to have a stable rocket with sufficient control to
    do the job, found by some trial-and-error. Using a stable rocket, having
    a cooperative target, using roll hold and an operator looking at video
    from the rocket, we can do a creditable job of coming pretty close to the
    target.
    Included are some IBM BASICA (GW-BASIC) computer programs to display
    possible engagement trajectories. They show the path of the rocket going
    after a target flying along the top edge from right to left. Sightlines
    are drawn from the rocket to the target. These paths are not dynamically
    correct. But they can reveal some general ideas.
    PROPONAV begins with the rocket on the ground in line with target path.
    You input the initial launch point in reference to where the target enters
    the view, the angle from vertical rocket axis to the target at launch, the
    navigational ratio and the rocket's speed compared to the target's speed.
    The program stops if the target got away, the rocket goes off the display
    or the rocket went past the target. A small crossbar is drawn at the rocket
    location at the end of the engagement. The screen height and width are
    equal by pixel count but not geometrically. The program may end when the
    target & rocket are very close with a BASIC round-off error.
    SIGHTANG is a display of what path would occur if an operator or a
    fuzzy-logic system kept the target at the same leading angle to the rocket
    axis at all times. This is "demand angle of look". It seems to be the
    system most amenable to a simple autonomous system. The program assumes
    the launch direction is in line with the target flight path and that roll
    is held fixed. The height and width are equal by pixel count. There is a
    speed look-up data table in lines 20-50. You can find out from a BASIC
    dynamics program, a video theodolite or by telemetry how your actual rocket
    performs with a given motor. Divide the expected flight time up to the
    target's altitude into 160 segments. Take the true speed in each interval,
    multiply by 1.24 (for proper aspect ratio on the screen) and key this into
    the DATA lines. Delete line 430 RESTORE. That is there only if the speed
    is constant and line 26 is the single data entry.
    Real-world rockets are a marvel of complex ingenuity. Integrating gyros,
    rate gyros, accelerometers, resolvers (control mixers), rollerons,
    (gyroscopic/aerodynamic roll stabilizers), range radar, Doppler radar
    (speed-finding "police" radar) and filters (computers to modify several
    control-input signals into desired outputs). They measure the true space
    motions and angles of the rocket and target. They must control the rocket
    correctly. Priority one is that they must work, in all circumstances, with
    many sources of "noise" and with little human assistance.
    We don't have those pressures because we're going slow and "setting up"
    the target. We will conveniently ignore noise. Like the sun-eye roll
    control that is causing the rocket to roll back and forth. Imperfect
    joystick skill. The time lag in the servos. The wind blowing. The control
    fins fluttering. The target not cooperating. The actual motor you're using
    isn't the same as the average motor. The fins aren't exactly straight. The
    list goes on.
    Real rockets must account for all these conditions. When they get it
    right, they're called kinetic energy weapons or "hittiles" (as opposed to
    "missiles"). They hit, not miss and their kinetic energy does the damage.
    This is a source of wonderment to us.
    We tried SACLOS (semi-automatic-command-line-of-sight) control using a
    simple circuit, TV camera and a bright light on a radio-control car. It
    was a full-throw right-or-left-turn, no-neutral system and did not work
    well.
    A word about potential for misuse is appropriate. We have encountered
    a few individuals who fear technological changes as the end of the world,
    especially if it seems to them to be "dangerous". Perhaps they fear
    backlash by federal regulators. But you can't uninvent any of the crucial
    components that make our projects possible. The motive is not to use this
    rocket or this report to promote mayhem, but to help us understand guidance
    principles.

    Abbreviations:
    CG - center of gravity (balance point)
    CP - center of (aerodynamic) pressure
    latax - lateral acceleration
    PROPONAV BASIC program
    SIGHTANG BASIC program
    SACLOS Autonomous Guidance
    Rocket backpack flight back to home page
    .

    BASIC Proportional Navigation Program
    20 REM PROPONAV rocket intercept display, input launch angle
    25 KEY OFF
    30 SCREEN 2: REM set screen hi-res
    40 INPUT "Offset (+319 to -319, + is to right) ";O
    50 INPUT "Launch angle (degrees, up = 0, + is to right) ";L
    60 INPUT "Navigational Ratio (2 to 5) ";N
    70 INPUT "Rocket Speed Multiplier (1 = target speed) ";S
    80 CLS: REM clear screen
    81 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PR INT:REM print data out of
    path of engagement
    82 PRINT "Offset=";O
    84 PRINT "Angle =";L
    86 PRINT "N.R. =";N
    88 PRINT "Speed =";S
    90 L=-L
    100 S=S*4.84: REM set rocket/target speeds to screen aspect ratio
    110 DRAW "BM639,199": DRAW "M+1,0": REM draw framing dot lower right
    130 DRAW "BM0,199":DRAW "M+1,0":REM draw framing dot lower left
    135 DRAW "BM0,0": DRAW "R3": REM draw target at upper left of field
    140 REM loop to draw target positions
    145 DRAW "BR61":DRAW "R3":C=C+1:IF C<10 THEN 140
    150 C=0 :REM zero counter
    155 DRAW "BM319,199" :REM move to bottom of screen, center
    160 DRAW "BR=O;":REM offset launch point
    165 REM initialize variables
    170 X2=639:X1=631 :REM set up initial sightline shift (8 steps)
    185 Y1=199:Y2=199:REM set initial height
    187 DRAW "A1": REM vertical reference
    190 REM main program loop
    191 X4=POINT(0):REM locate rocket horizontal position before move
    192 Y2=POINT(1):REM locate rocket vertical position before move
    200 DRAW "TA=L;U=S;":REM turn angle L, move rocket
    201 X3=POINT(0):REM locate rocket horiz pos after move
    202 Y1=POINT(1):REM locate rocket vert pos after move
    210 IF Y1=0 THEN 350:REM stop if rocket above target
    211 IF Y1<0 THEN 350
    212 IF Y1>199 THEN 350:REM stop if rocket hit ground
    220 T2=ATN((X2-X4)/Y2):REM calculate sightline before move
    225 T1=ATN((X1-X3)/Y1):REM calculate sightline after move
    230 T=(T2-T1)*57.3:REM determine sightline rotation in degrees
    260 IF X1=-9 THEN 350: REM end if target safely off screen
    290 L=L+(T*N):REM rotate rocket
    295 IF T>9 THEN PRINT:PRINT"Round-Off Stop":PRINT:GOTO 350:REM avoid roundoff
    catastrophe
    300 X2=X2-8:X1=X1-8 :REM move target 8 steps
    309 C=C+1: REM bump loop counter
    310 IF C=8 THEN C=0 :DRAW "NM=X2;,0;":REM draw sightline
    340 GOTO 190
    350 END

    BASIC Sighting Angle Rocket Guidance Program

    10 REM SIGHTANG rocket intercept display, constant sightline angle, integ
    navig
    20 REM List speed lookup table from dynamics program here, 160
    22 REM values that represent 1/160 of expected flight in units of
    24 REM target speed times 1.24375, and remove line 360 RESTORE.
    26 DATA 2
    38 KEY OFF
    40 SCREEN 2: REM set screen hi-res
    50 INPUT "Offset (+319 to -319, + is to right)? ",O
    60 INPUT "Sightline Angle? ",E
    80 CLS: REM clear screen
    90 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PR INT:REM print data out of
    path of engagement
    100 PRINT "Offset=(+319 to -319, + is to right)? ";O
    110 PRINT "Sight Angle=(degrees, up = 0, + is to right)? ";E
    120 DRAW "BM639,199": DRAW "M+1,0": REM draw framing dot lower right
    130 DRAW "BM0,199":DRAW "M+1,0":REM draw framing dot lower left
    140 DRAW "BM0,0": DRAW "R3": REM draw target at upper left of field
    150 REM loop to draw target positions
    160 DRAW "BR61":DRAW "R3":C=C+1:IF C<10 THEN 150
    170 C=0 :REM zero counter
    180 DRAW "BM319,199" :REM move to bottom of screen, center
    190 DRAW "BR=O;":REM offset launch point
    200 REM initialize variables
    210 X2=639:REM set up initial target sightline
    220 X4=329+O: REM set initial launch point
    230 Y2=199:REM set initial height
    240 REM main program loop
    250 T=ATN((X2-X4)/Y2):REM find initial angle
    255 T=(T*57.3)
    260 READ S
    270 T=-(T-E):REM rotate rocket
    280 DRAW "TA=T;U=S;":REM turn angle L, move rocket
    284 X4=POINT(0):REM locate rocket horiz position
    286 Y2=POINT(1):REM locate rocket vertical position
    288 IF X4<=0 THEN 380
    290 IF Y2=0 THEN 380:REM stop if rocket above target
    300 IF Y2<0 THEN 380
    310 IF Y2>199 THEN 380:REM stop if rocket hit ground
    320 X2=X2-4 :REM move target 4 steps
    330 IF X2<0 THEN 380: REM end if target safely off screen
    340 C=C+1: REM bump loop counter
    350 IF C=16 THEN C=0 :DRAW "NM=X2;,0;":REM print sightlines
    360 RESTORE
    370 GOTO 240

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    لا اله الا الله محمد رسول الله
    تفضل , هنا تقرأ القرآن

  3. [43]
    م المصري
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    عضو شرف


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    وسام الشكر

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    تفضلوا هذا ,,,,,,,

    ارجو ان يعجبكم

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    الملفات المرفقة
    لا اله الا الله محمد رسول الله
    تفضل , هنا تقرأ القرآن

  4. [44]
    نايف علي
    نايف علي غير متواجد حالياً
    عضو فائق التميز
    الصورة الرمزية نايف علي


    تاريخ التسجيل: Sep 2006
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    السلام عليكم ورحمة الله وبركاته

    أشكرك أخي Aboayoy

    ولدي استفسار عن البطاريات المضادة للصواريخ مثل بطاريات باتريوت....فكرة بسية لو سمحت...:)

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    إذا اعتاد الفتى خوض المنايا ::: فأهون مايمر به الوحول

  5. [45]
    م المصري
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    عضو شرف


    تاريخ التسجيل: May 2006
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    وسام الشكر

     وسام كبار الشخصيات

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    الاخ العزيز hss :

    نظام الصواريخ الامريكي باتريوت ,,,,,

    من المعروف انه يوجد صواريخ مضاده للطائرات ,,,, و تتميز طبعا الصواريخ بقدرات اكبر من الطائرات من حيث السرعه و المناوره ,,,

    و لكن من الصعوبه بمكان ان تصمم صاروخا مضادا للصواريخ ,,,

    و كان في الماضي يعتبر ان اطلاق صاروخ نحو هدف معين ,,,,, معناه ان الصاروخ ماضي الي هدفه لا محاله ,,, الا لو تحطم الصاروخ من تلقاء نفسه

    و مع تزايد خطوره الصواريخ "الباليستيه" المستخدمه في الضرب المساحي "المدن و الاخري و الاهداف الارضيه" ,,,,, اتجهت الولايات المتحده الي تطوير نظام صاروخ مضاد للصواريخ الباليستيه

    و تعتمد فكرة هذا النظام علي الاكتشاف المبكر جدا للصاروخ المهاجم و من ثم الرد عليه بدفعة صواريخ من 5 الي 10 صواريخ ,,,, تقابل الصاروخ المهاجم في مرحلة reentry مباشره فتقضي علي الصاروخ و تفجره في الجو

    و كان اول اختبار لهذه المنظومه المتطوره جدا ,,,كان ابان حرب الخليج عندما اطلقت العراق بقيادة الرئيس الراحل صدام حسين دفعات من صواريخ سكود الروسيه و المطوره عراقيا علي اسرائيل ,,,, و مع ذلك نجحت بعض الصواريخ العراقيه في السقوط علي اسرائيل

    كما مني النظام بهزيمه ثقيله عندما سقط صاروخ عراقي علي قاعده امريكيه بالسعوديه و دمرها تماما رغم اطلاق 11 صاروخ باتريوت علي هذا الصاروخ العراقي

    و بعد هذه التجربه اتضح عدم دقة هذه الصواريخ كما يحتاج نظام الانذار المبكر الي تعديلات و قد خضعت هذه المنظومه الي سلسله تطويرات جذريه حتي الان ,,,, و يذكر ان البطاريات باتريوت المنتشره حول العالم الان هي من الجيل المطور ,,,, كما يلاحظ ان تكلفة تدمير صاروخ واحد تصل الي حوالي 50 مليون دولار مما يجعل هذا النظام مكلفا لأقصي درجه

    و ننوه علي ان اسرائيل تنتج نظاما مماثلا و متطور جدا يسمي آرو و لم يتم اختباره عمليا ,,,, لكن تجارب التصنيع اثبتت تفوقا فائقا

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    لا اله الا الله محمد رسول الله
    تفضل , هنا تقرأ القرآن

  6. [46]
    ghost
    ghost غير متواجد حالياً
    عضو


    تاريخ التسجيل: Aug 2006
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    اخى Aboayoy لقد سجلتك عندى ولم اجدك
    ارجو ان تقبلنى عندك وهذا يا--------هو ghostair2000
    وجزاك الله خيرآ

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  7. [47]
    ghost
    ghost غير متواجد حالياً
    عضو


    تاريخ التسجيل: Aug 2006
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    اخىAboayoy ادعوك لمشاهده هذا الموضوع
    http://www.arab-eng.org/vb/showthread.php?t=40250

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  8. [48]
    م المصري
    م المصري غير متواجد حالياً
    عضو شرف


    تاريخ التسجيل: May 2006
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    وسام الشكر

     وسام كبار الشخصيات

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    الصديق العزيز ghost ,,,,
    شرف لي ان تسجلني عندك ,,, و لكن اين سجلتني و لم تجدني ,,؟؟
    و انا اعتز بصداقتك؟؟

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    لا اله الا الله محمد رسول الله
    تفضل , هنا تقرأ القرآن

  9. [49]
    م/ مصطفي
    م/ مصطفي غير متواجد حالياً
    عضو شرف
    الصورة الرمزية م/ مصطفي


    تاريخ التسجيل: Apr 2006
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    وسام الشكر

     وسام كبار الشخصيات

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    بـارك اللــه فيكــم اخواني " ghost & Aboayoy " :)

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    عـوده مره أخري الي هذا الملتقي الاكثر من رائع :)

  10. [50]
    ghost
    ghost غير متواجد حالياً
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    السلام عليكم اخى Aboayoy
    هذا *****ى الخاص وانا موجود الان اون لاين
    ghostair2000 على ياهو
    منتظرك اخى

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