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Chapter 6 / Missile Guidance
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6.1 Missile Guidance Simulator
Figure 6-1 shows how the previous simulators combine to support the
Missile Guidance software that contains a generic missile model,
conventional guidance laws, and a trajectory optimiser. This is the final
simulator embedded in the software infrastructure described in §8. For
security and commercial reasons the MBDA missile models are strictly
segregated and only the generic missile is described in this document, The
generic missile is activated if (MS_TYPE := 0).
•
Modules D_MISSILE and I_MISSILE perform initialisation and model
characterisation. The Target simulator is activated first within the
integration loop controlled by DX_CONTROL. The remaining reference
data listed in §22.2 are provided at 4 kHz, implemented so as to be robust
prior to launch, and whilst the missile is slowly rotating in the launcher.
After launch STOP_MONITOR and C_APPROACH monitor the program
termination and impact conditions described in §22.2.1. If SCREEN is set to
1, a progress report is written to the screen at 10 Hz containing:
Simulation time
• Target range
• Missile time-to-go ( post launch only )
• Missile to target LOS range ( post launch only)
• Missile speed ( post launch only)
The missile functions are stimulated by the reference or estimated data listed
in §22.2 depending on the active sensors, target tracking and missile state
observer controls. This data is provided at a rate commensurate with the
fastest element in the missile control system, in this case 400 Hz. When the
observers are active the state errors and covariances are analysed by
CV_CONTROL and CV_STATS, as described in §22.12. At launch
MS_CONTROL is activated comprising the launcher and missile models and
their linear and angular dynamics. The missile models are computed on the
initial integrator pass when INDEXI is 1 at the clock rates shown.
6.2 Missile Airframe
MS_AIRFRAME selects the airframe model, in this case MS_AF_0 which is
is active from launch at time (tL) to the end of the boost phase lasting
(tB := 4s), after which the airframe parameters remain constant. The generic
missile diameter (dm) used to determining the drag force is 0.18 m. During
boost the propellant mass reduces linearly with time,
[ t , t + t ] ⇒ m : = 80 − 35 ( t t )
t ∈
⋅
L
L
B
6-3
m
B
Equation 6.2-1