Analytical study of effects of autopilot operation on motions of a subsonic jet- transport airplane in severe turbulence
Autopilot control of subsonic jet transports in severe turbulence
Gilbert, W. P.↗
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A case study of the Apollo lunar module digital autopilot
Design criteria and constraints of Apollo lunar module digital autopilot
Cox, K. J.↗
Effects of varying levels of autopilot assistance and workload on pilot performance in the helicopter formation flight mode Final technical report, Dec. 1967 - Apr. 1968
Varying levels of autopilot assistance and workload effects on pilot performance in helicopter formation flight mode
Anderson, P. A.↗
Preliminary study of airplane-autopilot response to atmospheric turbulence
Preliminary study of airplane-autopilot response to atmospheric turbulence while operating in altitude-hold and attitude-hold modes
Oehman, W. I.↗
Apollo experience report: Guidance and control systems - Digital autopilot design development
The development of the Apollo digital autopilots (the primary attitude control systems that were used for all phases of the lunar landing mission) is summarized. This report includes design requirements, design constraints, and design philosophy. The development-process functions and the essential information flow paths are identified. Specific problem areas that existed during the development are included. A discussion is also presented on the benefits inherent in mechanizing attitude-controller logic and dynamic compensation in a digital computer.
Peters, W. H.↗
Pulse-width-modulated servo valve for autopilot system
Valve was developed for autopilot wing-lever system and is to be used in light, single-engine aircraft. Valve is controlled by electronic circuit which feeds pulse-width-modulated correction signals to two solenoids. Valve housing is cast from plastic, making it very economical to fabricate.
Garner, H. D.↗
Flight evaluation of a Mach 3 cruise longitudinal autopilot
At high Mach numbers (approximately 3) and altitudes greater than 70,000 feet, the original altitude and Mach hold modes of the YF-12 autopilot produced aircraft excursions that were erratic or divergent or both. Data analysis and simulator studies showed that static pressure port sensitivity to angle of attack had a detrimental effect on the performance of both altitude and Mach hold modes. Good altitude hold performance was obtained when a high-passed pitch rate feedback was added to compensate for angle-of-attack sensitivity and the altitude error and integral altitude gains were reduced. Good Mach hold performance was obtained with the removal of angle-of-attack sensitivity.
Gilyard, G. B.↗
CSM digital autopilot testing in support of ASTP experiments control requirements
Results are presented of CSM digital autopilot (DAP) testing. The testing was performed to demonstrate and evaluate control modes which are currently planned or could be considered for use in support of experiments on the ASTP mission. The testing was performed on the Lockheed Guidance, Navigation, and Control System Functional Simulator (GNCFS). This simulator, which was designed to test the Apollo and Skylab DAP control system, has been used extensively and is a proven tool for CSM DAP analysis.
Rue, D. L.↗
Results from flight and simulator studies of a Mach 3 cruise longitudinal autopilot
At Mach numbers of approximately 3.0 and altitudes greater than 21,300 meters, the original altitude and Mach hold modes of the YF-12 autopilot produced aircraft excursions that were erratic or divergent, or both. Flight data analysis and simulator studies showed that the sensitivity of the static pressure port to angle of attack had a detrimental effect on the performance of the altitude and Mach hold modes. Good altitude hold performance was obtained when a high passed pitch rate feedback was added to compensate for angle of attack sensitivity and the altitude error and integral altitude gains were reduced. Good Mach hold performance was obtained when the angle of attack sensitivity was removed; however, the ride qualities remained poor.
Gilyard, G. B.↗
Applications of the hybrid coordinate method to the TOPS autopilot
Preliminary results are presented from the application of the hybrid coordinate method to modeling TOPS (thermoelectric outer planet spacecraft) structural dynamics. Computer simulated responses of the vehicle are included which illustrate the interaction of relatively flexible appendages with an autopilot control system. Comparisons were made between simplified single-axis models of the control loop, with spacecraft flexibility represented by hinged rigid bodies, and a very detailed three-axis spacecraft model whose flexible portions are described by modal coordinates. While single-axis system, root loci provided reasonable qualitative indications of stability margins in this case, they were quantitatively optimistic when matched against responses of the detailed model.
Fleischer, G. E.↗
NASA TLA workload analysis support. Volume 3: FFD autopilot scenario validation data
The data used to validate a seven time line analysis of forward flight deck autopilot mode for the pilot and copilot for NASA B737 terminal configured vehicle are presented. Demand workloads are given in two forms: workload histograms and workload summaries (bar graphs). A report showing task length and task interaction is also presented.
Sundstrom, J. L.↗
Simple Magnetometer for Autopilots
Simple, low-cost magnetometer is suitable for heading-reference applications in autopilots and other directional control systems. Sensing element utilizes commercially available transformer core; and supporting electronics consist of one transistor, two readily-available integrated-circuit chips, and associated resistors and capacitors.
Garner, H. D.↗
The state of the art of general aviation autopilots
The study is based on the information obtained from a general literature search, product literature, and visitations and interviews with manufacturers, users, and service centers. State of the art autopilots are documented with respect to total systems, components, and functions. Recommendations concerning potential areas of further research are also presented.
See, M. J.↗
Analysis of several glidepath and speed control autopilot concepts for a powered lift STOL aircraft
Longitudinal performance and control utilization data are compared for several different automatic approach autopilot implementations in a powered lift STOL aircraft. As few as two, to as many as four laws reflecting both backside and frontside control techniques. The data are developed from analysis and simulation, but represent configurations which were demonstrated in flight. Transient response characteristics from initial glidepath offsets are presented, along with system operation in turbulence. In furnishing quantitative data in controlled levels of simulated turbulence, these results provide a useful supplement to various flight investigations (including those employing manual control) that involved a comparison of control techniques in this type of aircraft.
Hindson, W. S.↗
The digital autopilot for thrust vector control of the Shuttle Orbital maneuvering system
This paper describes the requirements for and the design, development and performance of the digital autopilots (DAPs) for thrust vector control, utilizing the orbital maneuvering system (OMS) of the Space Shuttle Orbiter. The hardware and software requirements which caused the design to assume its current form are described. Also, the design synthesis, which considered rigid body stability margins, bending and slosh stabilization, guidance loop compensation, off-nominal performance and hardware and software limitations is presented. The performance of the OMS control system is summarized utilizing flight data from the first three Space Transportation System (STS) flights.
Penchuk, A.↗
Design of a helicopter autopilot by means of linearizing transformations
An automatic flight control systems design methods for aircraft that have complex characteristics and operational requirements, such as the powered lift STOL and V/STOL configurations are discussed. The method is effective for a large class of dynamic systems that require multiaxis control and that have highly coupled nonlinearities, redundant controls, and complex multidimensional operational envelopes. The method exploits the possibility of linearizing the system over its operational envelope by transforming the state and control. The linear canonical forms used in the design are described, and necessary and sufficient conditions for linearizability are stated. The control logic has the structure of an exact model follower with linear decoupled model dynamics and possibly nonlinear plant dynamics. The design method is illustrated with an application to a helicopter autopilot design.
Meyer, G.↗
A flight test maneuver autopilot for a highly manueverable aircraft
A flight test maneuver autopilot (FTMAP) is currently being flown to increase the quality and quantity of the data obtained in the flight testing of the highly maneuverable aircraft technology (HiMAT) remotely piloted research vehicle (RPRV). The FTMAP resides in a ground-based digital computer and was designed to perform certain prescribed maneuvers precisely, while maintaining critical flight parameters within close tolerances. The FTMAP operates as a non-flight-critical outer loop controller and augments the vehicle primary flight control system. The inputs to the FTMAP consist of telemetry-downlinked aircraft sensor data. During FTMAP operation, the FTMAP computer replaces normal pilot inputs to the aircraft stick and throttle positions. The FTMAP maneuvers include straight-and-level flight, level accelerations and decelerations, pushover pullups, and windup turns. The pushover pullups can be executed holding throttle or Mach number fixed. The windup turns can be commanded by either normal acceleration or angle of attack. The operational procedures, control mode configuration, and initial simulation results are discussed.
Roncoli, R. B.↗
Development of control laws for a flight test maneuver autopilot for an F-15 aircraft
An autopilot can be used to provide precise control to meet the demanding requirements of flight research maneuvers with high-performance aircraft. The development of control laws within the context of flight test maneuver requirements is discussed. The control laws are developed using eigensystem assignment and command generator tracking. The eigenvalues and eigenvectors are chosen to provide the necessary handling qualities, while the command generator tracking enables the tracking of a specified state during the maneuver. The effectiveness of the control laws is illustrated by their application to an F-15 aircraft to ensure acceptable aircraft performance during a maneuver.
Alag, G. S.↗