THCS Generalized Airplane Control System Design

The Total Energy Control System (TECS) was developed in the early eighties to overcome well known safety/design deficiencies of traditional Single Input/Single output (SISO) based Flight Guidance and Control (FG&C) systems. TECS uses generalized Multi Input/Multi Output (MIMO) based airplane control strategies to functionally integrate all desired automatic and augmented manual control modes and achieve consistently high performance for airplane maneuvering in the vertical plane. This paper documents further insights gained over the past years on TECS design details for achieving precision control decoupling, integration of augmented manual control modes, embedded envelope protection functions and innerloop design using airplane dynamic model inversion. Additionally, non-linear design aspects are discussed, including thrust limiting, energy management, maneuver rate limiting and mode logic.