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guidance, flight mechanics and trajectory optimization

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are applied to Min (fl), the range of Min (f ) can be found for various<br />

admissible values of xl. This step can be thought of as the first stage<br />

of a three stage decision process, where the various choices for xl can<br />

be as many as desired within the limits 0=X, 4/O.<br />

Now that all the choices for the first decision have been investigated,<br />

the second decision must be considered. Again, care must be taken in the<br />

specification of the constraint equations. The optimal value function for<br />

the second decision is<br />

The constraints on 3 <strong>and</strong> x2 are chosen to be<br />

$=(-+2X; (2.2.26)<br />

X, + x2 = AZ OLAz g 10 (2.2.27)<br />

For each value of A2 that is to be investigated, there are many combinations<br />

of x, <strong>and</strong> x2 to be considered. More precisely, the number of combinations<br />

of "I <strong>and</strong> x2 to be considered is the same as the number of AlIs that are<br />

less than or equal to the A being considered, e.g., if Al was investigated<br />

for comb~a;i~~s5~u,'I A ;de&=tiedis 5 being considered, then the following<br />

A<br />

- %, - x2<br />

0 5<br />

5- 0<br />

The third decision does not require as much computation as the others in this<br />

case because of the original constraint equations.<br />

;“, + xz f z 3<br />

XL ZO<br />

Since the first<br />

%<strong>and</strong> +x<br />

"1 2'<br />

two decisions were investigated for many possible<br />

it is only necessary to consider<br />

values of<br />

= /o<br />

x, f x2 + x3 = IO<br />

because the various choices for will specify 5 + x2 = 10 - 3 <strong>and</strong> these<br />

possibilities have already been 3 ' vestigated.<br />

(2.2.28)<br />

The arithmetic solution will now be shown so that the previous discussion<br />

will be clear. For simplicity, only integers will be considered for the<br />

allowable values for xl, x2, <strong>and</strong> x3. A table can be constructed for the<br />

first decision as follows:<br />

36

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