A new design approach to achieve a minimum impulse limit cycle in the presence of significant measurement uncertaintiesA new design was developed for the Space Shuttle Transition Phase Digital Autopilot to reduce the impact of large measurement uncertainties in the rate signal during attitude control. The signal source, which was dictated by early computer constraints, is characterized by large quantization, noise, bias, and transport lag which produce a measurement uncertainty larger than the minimum impulse rate change. To ensure convergence to a minimum impulse limit cycle, the design employed bias and transport lag compensation and a switching logic with hysteresis, rate deadzone, and 'walking' switching line. The design background, the rate measurement uncertainties, and the design solution are documented.
Document ID
19820055437
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Martin, M. W. (Lockheed Engineering and Management Services Co. Houston, TX, United States)
Kubiak, E. T. (NASA Johnson Space Center Houston, TX, United States)