in this paper, a nonlinear model of the underactuated six degrees of freedom (6 dof) quadrotor helicopter was derived based on the newton-euler formalism. a new nonlinear robust control strategy was proposed to solve the stabilizing and path following problems in presence of external disturbances and parametric uncertainties. the proposed control structure consist of a sliding mode control base...

this paper proposes a new method of gain scheduling control design for a nonlinear system which is described as linear parameter varying form. a performance measure based on linear matrix inequality is introduced. to consider stability and performance measures in design process, the h∞ loop-shaping method is used to design the local controllers, which can be described as state feedback observer...

A general method for constructing local Lie groups which are not contained in any global Lie group is described. These examples fail to satisfy the global associativity axiom which, by a theorem of Mal’cev, is necessary and sufficient for globalizability. Furthermore, we prove that every local Lie group can be characterized by such a covering construction, thereby generalizing Cartan’s global v...

This paper contributes a technique that expands the set of object invariants that one can reason about in modular verification. The technique uses history invariants, two-state invariants that describe the evolution of data values. The technique enables a flexible new way to specify and verify variations of the observer pattern, including iterators. The paper details history invariants and the ...