SST Longitudinal Control System Design and Design Processes Hardened Stability Augmentation Design

摘要

The SST configuration and performance trades that resulted in balancing the longitudinal axis of the airplane to be aerodynamically unstable in subsonic flight are briefly described. To ensure safety, an extremely reliable stability augmentation system called a 'hard SAS' (HSAS) was developed. The following aspects of the SST longitudinal control systems design are discussed: (1) the design philosophy and criteria used to achieve the extreme reliability requirements, (2) the impact of the unstable airframe on the control law synthesis and controls mechanization requirements, (3) the control system mechanization development, and (4) problems encountered and solutions developed in designing a quadruple-redundant control system to meet the very demanding control requirements. (Author)