Robust Attitude Control of Multibody Aircraft with Preview-Based Control Compensation

This paper investigates the robust attitude control for wingtip-connected multibody aircraft, using preview-based control compensation mechanism to address the issues of inherent wingtip couplings. A constrained multibody dynamics model is first derived to obtain the nonlinear and linearised formulations for multibody aircraft. The H \(_{\infty }\) control is employed to synthesize the pitch angle and forward velocity controller in the longitudinal channel, while the H \(_{\infty }\) preview control is employed to synthesize the roll angle and yaw rate controller in the lateral channel. The preview control scheme enables the usage of future reference commands as feedforward information to synthesize appropriate control compensation to reduce the impact of wingtip couplings between adjacent aircraft units. Simulation studies conducted based on the nonlinear model show that the preview-based H \(_{\infty }\) control system is able to achieve better control effectiveness and disturbance rejection performance, compared to the baseline regular H \(_{\infty }\) control system without preview. These demonstrate that the mechanism of control compensation can greatly benefit the flight control of multibody aircraft.