Reconfigurable Controller Design Of Stratospheric Demonstrating Airship

The stratospheric airship is one of the kinds of near-space vehicles, whose lift is provided by the air buoyancy. As a new information platform, the stratospheric airship can be used for a long time earth observation and communication utilities for both military and civil area. The airship is equipped with both aerodynamic control surfaces and vectored thrusts, so it is possible to achieve reconfiguration by redundant configuration. Two control allocation methods are proposed for designing a reconfigurable controller. The paper is organized as follows:1. Firstly, control redundancy features of the airship are analyzed, the possible failures are classified, and the reconfigurable mechanism of the airship are studied, then an overall design of reconfigurable controller based on control allocation technique is given;2. A traditional control method is employed to design the upper controller, and then the attitude moment can be distributed among the actuators based on two control allocation methods, Dynamic Inverse and Sequential Quadratic Programming. When dynamic inverse method is used, a map from actuator state to efficiency weighted-matrix is established, and then the rapid reconfiguration can be achieved only by changing efficiency value. When in sequential quadratic programming approach, the composite performance index can be established and the control constraints can be taken into account, then an optimized allocation can be realized among these actuators.3. Finally, simulations are presented under normal and failure condition. Simulation results demonstrate that both of the two controllers all performance well in control and reconfiguration. A fast reconfiguration can be obtained in dynamic inverse method, but the choice of control variable is limited; and an optimized allocation can be realized in sequential quadratic programming method, but with large calculation.