Integrated guidance and control path following and dynamic control allocation for a stratospheric airship with redundant control systems

Abstract

This paper proposes an integrated guidance and control path following and dynamic control allocation method based on constrained optimal quadratic programming for the stratospheric airship with redundant systems. The control system is divided into two levels. A novel planar geometric path following control method is presented as the high-level controller. The method consists of planar position tracking controller, velocity regulator, attitude and altitude stabilizations. The velocity regulator contributes to the directionality of path following and decreases the number of singularity points for the closed-loop system. The control input of the actuators for the low-level controller can be obtained by two principles, one is keeping the control input close to the desired steady-state value, and the other is minimizing the change between the current input and the preceding one as well as the one before. This approach considers both physical constraints and dynamic responses of actuators. When a fault occurs, it can change the weight coefficient of the actuator to ensure the fault is well distributed among the fault-free actuators without reconfiguring the high-level controller. Several simulations illustrate the feasibility of the control law and show advantages for practical application.