Abstract: In view of coupling and uncertain characteristics of nonlinear control system for bank-to-turn(BTT) low-speed cruise vehicles, a robust backstepping controller is designed to follow the control command. The dynamic model of cruise vehicles is transformed into a block form which is suitable for backstepping algorithm. The block form is assumed to be composed of a nominal model and uncertain terms. The uncertain terms are derived and described by using the Leibniz rule in infinitesimal calculus. On this basis, the basic form of the control law is derived by exploiting backstepping algorithm. The modification of robust function, i.e., a new symbolic function, is conducted to compensate the unmatched uncertainties. Lyapunov redesign technique is introduced to control the matched uncertainties. Comparative simulation cases are implemented to validate the improved robust backstepping algorithm. The results indicate that the presented control response can quickly track the commands of angle of attack, sideslip angle and bank angle, which shows the strong robustness of the system. Key

Key words: cruisevehicle, bank-to-turn, robustbacksteppingalgorithm, unmatcheduncertainterm