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Thesis - Leigh Moody.pdf - Bad Request - Cranfield University

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Appendix I / Utilities / Digital Filters<br />

_ _<br />

22.8.19 Angular Range Wrapping<br />

PI_WRAP takes an angle (X) and maps it onto the range [-π ,π].<br />

When in range,<br />

22.8.20 Rate Limiter<br />

y : = PI_WRAP<br />

ξ<br />

0<br />

22.8-13<br />

: =<br />

X<br />

( X )<br />

[ − π , π ] ⇒ ξ : = ξ − 2 ⋅ π ⋅ sign ( 1 , ξ )<br />

ξ k ∉<br />

k + 1<br />

[ − π , π ] ⇒ ξk<br />

1 : = ξk<br />

ξ k ∈<br />

+<br />

ξ<br />

k + 1<br />

∈<br />

[ − π π ] ⇒ y : = ξk<br />

1<br />

, +<br />

k<br />

Equation 22.8-91<br />

Equation 22.8-92<br />

k<br />

Equation 22.8-93<br />

Equation 22.8-94<br />

Equation 22.8-95<br />

RATE_LIMIT takes 50 inputs (X), their input rate limits (DXL), and time<br />

increment between updates (∆t), returning the rate-limited input and a flag<br />

indicating whether the input has been rate-limited.<br />

y<br />

: = RATE_LIMIT<br />

X<br />

i − Xi−1<br />

( X , DXL , ∆t<br />

, LIMIT , N ) ≡ ϕ ( X , X&<br />

)<br />

≤<br />

X&<br />

X : =<br />

L<br />

− 1<br />

⋅ ∆t<br />

⇒<br />

X<br />

0<br />

⎧<br />

⎪<br />

⎨<br />

⎪<br />

⎩<br />

y<br />

y<br />

: =<br />

: =<br />

X<br />

i<br />

LIMIT<br />

RL<br />

I<br />

L<br />

Equation 22.8-96<br />

Equation 22.8-97<br />

⎫<br />

⎪<br />

⎬<br />

⎪<br />

⎭<br />

Equation 22.8-98

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