Adaptive Dynamic Inversion Control of Linear Plants With Control Position Constraints

For a class of linear time-invariant systems with uncertain parameters, this paper proposes and develops a notion of the Domain of Control Authority to achieve stable adaptation in the presence of control position limits. The Domain of Control Authority defines the subspace in which the plant state can be driven in any arbitrary direction by bounded control. No restrictions are placed on the stability of the open-loop system. To address the problem of containing the state within the Domain of Control Authority, a switching control strategy with a direction consistent control constraint mechanism is developed for an unstable plant. This restricts the resultant direction of the rate of change of the state to be the same as the direction of the desired reference state. Stability proofs are provided, and controller performance is demonstrated with numerical examples of a two degree-of-freedom dynamic model and an F-16XL aircraft model.