Research On Distributed Cooperative Control Technoloyg Of Morphing Wings

The design of conventional fixed wing aircraft is constrained by the conflicting requirements ofmultiple objectives. The development of new smart materials together with the always present needfor better aircraft performance is increasingly prompting designers towards the concept of morphingwing. Morphing wing aircraft are flight vehicles that change their shape to effect both a change in themission of the aircraft and to perform flight control without the use of conventional control surfacesor seams. Aircraft constructed with morphing wing technology promise the distinct advantages ofbeing able to fly multiple types of missions, to perform radically new manoeuvres not possible withconventional control surfaces, to be more fuel efficient, and to provide a reduced radar signature. Anarray of government agencies, universities and companies in the United States and Europe arespending an increasing amount of resources on research projects that will revolutionize the costs ofbuilding and operating aircraft in the near future.First, a morphing wing using distributed intelligent actuator systems was modeled. A skin iscovered on electromechanical actuators whose movement deforms the airfoil. Based on this morphingwing model and performance requirements of the morphing wing, a local cost function was definedfor each agent to coordinate the dynamic behaviors between the agents. After redescribing thetopological structure of information exchange in the local cost function using graph theory, wedecoupled the morphing wing system and proposed a distributed cooperative control scheme. Thecontrol scheme could drive the airfoil to reach the expected shape and maintain the airfoil smoothduring the deformation.Then the conditions for convergence to consensus of morphing wing system with sampledcommunication was analyzed. According to a reformulation of Nyquist criterion and systemdecoupling method, the diagrammatic sufficient and necessary conditions for holding the systemstable were obtained. By using these conditions and Chebyshev polynomials, we derived thealgorithm of stability region of distributed cooperative Controllers. The morphing wing systems withunknown time-delays were also investigated. According to Lyapunov-Krasovskii stability theorem,the robust stability of morphing systems was guaranteed by solving a set of linear matrix inequalities.The conditions for convergence to consensus of morphing wing systems was analyzed under suchsituations as the unstable network, the agent failure, etc. By using the convexity of the closed-loopcharacteristic polynomials, argument principle and the proposed diagrammatic stability criterion, thesufficient and necessary conditions for holding the system robust stable with any topological connectivity were obtained. A robust stability criterion was given using the convexity of the linearmatrix inequality and an algorithm was proposed to design the controllers using the conecomplementary linearization method.Morphing wing systems with input and skin constraints were investigated. According to theKarush-Kuhn-Tucker sufficient and necessary conditions, positively invariant set principle and theLyapunov function, an ellipsoidal set was constructed. Once the initial state is in the set, the agentmeets the input constraints. To deal with the effect of the skin, a dynamical model of an agent wasmodeled, the distributed cooperative control law was improved and the stability of morphing wingsystems was analyzed using Lyapunov-Krasovskii functional.Finally, we developed an experimental platform of morphing wing control systems which consistedof the cabinet, the intelligent actuator module, the network module and the upper computer module,together with the distributed cooperative control software of the morphing wing systems including thesampled control program and the upper computer program. Simulation examples of the morphingwing system using Matlab and experiments on the experimental platform were carried out. The resultsverify the validity of the distributed cooperative control scheme.