Design of a total energy control autopilot using constrained parameter optimization

Abstract

The application of a multivariable control design method based on constrained parameter optimization to the design of a multiloop aircraft flight control system is described. Specifically, the design method is applied to the direct synthesis of a multivariable inner-loop feedback control system based on total energy control principles. The design procedure offers a structured approach for the determination of a set of controller gains that meet design specifications in closed-loop stability, command tracking performance, disturbance rejection, and limits on control activities. The presented approach may be applied to a broader class of multiloop flight control systems. Direct tradeoffs between many real design goals are rendered systematic by this method following proper formulation of the design objectives and constraints. Performance characteristics of the optimized design have been improved over the current autopilot design on the B737-100 Transport Systems Research Vehicle at the landing approach and cruise conditions, particularly in the areas of closed-loop damping and control activity in the presence of turbulence.