21-01-2012, 05:12 PM
A FORCE MEASUREMENT SYSTEM FOR MISSILE GUIDANCE CONTROL USING JET VANES
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INTRODUCTION
The effectiveness of jet vane guidance control
can be determined by measuring the forces
and moments on the jet vanes during operation.
The force components can then be used to determine
the steering effect on the motor missile configuration.
For this paper, the problem of developing
a force measurement system to determine forces and
moments on the jet vanes immersed in the exhaust
stream of the first stage motor of the Scout
missile is analyzed. In addition to providing a
continuous measurement of aerodynamic forces and
moments, the system was required to ensure a constant
depth of vane immersion in the exhaust gases
during vane rotation.
Description of Selected Balance
The multi-component internal strain-gagebalances
used are of the floating-frame type,
Figure 2. The primary frame consists of an inner
shell (sting) which is secured to the model inner
support case through six load sensing elements.
The inner case is supported within the model
outer case by roller bearings.
Structural Support Members
In a redundant system, as all multi-component
force measurement systems are, it follows that
interaction can be minimized by reducing interrelated
deflections. In an ideal system which
completely eliminates interactions, the load elements
are infinitely rigid in the direction of
principle loads and completely compliant to end
rotations and transverse deflections.
