Control of Wing-Rock Motion of Slender Delta Wings

A theoretical analysis is conducted to determine the optimal control input for wing-rock suppression through a Hamiltonian formulation. The optimality equations are analyzed through Beecham-Titchener's averaging technique and numerically integrated by a backward-differentiation formulas method developed for implicit differential equations. The weighting factors in the cost function are shown to be related explicitly to the system output damping and frequency. A numerical model constructed for an 80-deg delta wing is solved to illustrate the results. It is shown that Beecham-Titchener's technique is accurate in determining the necessary control function to suppress wing rock. From the numerical results, it is also shown that an effective way to suppress wing rock is to control the roll rate. System sensitivity is investigated by determining variations in system output damping and frequency with aerodynamic model coefficients. The results show that higher sensitivity corresponds to lower system damping.