Attitude Stabilization Control of a Quadrotor UAV by Using Backstepping Approach

<table>The response of the unit quaternion <svg height="11.65" id="M196" style="vertical-align:-2.79825pt" version="1.1" viewbox="0 0 9.5749998 11.65" width="9.5749998" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,8.1)"><path d="M536 -181v-24h-267v24q48 7 60 24q13 16 13 67v132q-44 -56 -123 -56t-132 63q-53 65 -53 170q0 108 61 181t161 73q38 0 66 -12t66 -44l77 55h16v-595q0 -30 10 -40.5t45 -17.5zM342 98v256q0 41 -18.5 64t-48.5 23q-45 0 -70 -52t-25 -153q0 -96 24.5 -146t68.5 -50
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</svg> in the presence of external disturbances.</table>

Mathematical Problems in Engineering

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Figure 6

Figure 6: Attitude Stabilization Control of a Quadrotor UAV by Using Backstepping Approach 