An explicit model-matching approach to lateral-axis autopilot design

The application of a linear multivariable control law design methodology to an autopilot design for large transport aircraft is described. The design method is an explicit model-matching approach, whereby compensator parameters are tuned via a least-squares optimization approach to minimize the error between the desired and the actual closed-loop frequency responses. This method incorporates some recent theoretical advances, including controller parameterization and plant factorization, and has been implemented within the ISICLE software package, a MATLAB-based control design toolbox. A desirable feature of the ISICLE design software is the capability to constrain the compensator dynamic order and structure, issues motivated by the necessity for low complexity implementations in order to simplify gain scheduling and limit protection.<>