Nonlinear Tracking Control Using a Robust Differential-Algebraic Approach.

This dissertation presents the development and application of an inherently robust nonlinear trajectory tracking control design methodology which is based on linearization along a nominal trajectory. The problem of trajectory tracking is reduced to two separate control problems. The first is to compute the nominal control signal that is needed to place a nonlinear system on a desired trajectory. The second problem is one of stabilizing the nominal trajectory. The primary development of this work is the development of practical methods for designing error regulators for Linear Time Varying systems, which allows for the application of trajectory linearization to time varying trajectories for nonlinear systems. This development is based on a new Differential Algebraic Spectral Theory. The problem of robust tracking for nonlinear systems with parametric uncertainty is studied in relation to the Linear Time Varying spectrum. The control method presented herein constitutes a rather general control strategy for nonlinear dynamic systems. Design and simulation case studies for some challenging nonlinear tracking problems are considered. These control problems include: two academic problems, a pitch autopilot design for a skid-to-turn missile, a two link robot controller, a four degree of freedom roll-yaw autopilot, and a complete six degree of freedom Bank-to-turn planar missile autopilot. The simulation results for these designs show significant improvements in performance and robustness compared to other current control strategies

A Novel Approach to Imaging using a Dual Field-of-View Sensor

Most modern aircraft, such as missile systems and unmanned aerial vehicles have limited size, weight, power and cost (SWaP-C) capability. As the defence budget for military forces such as the UK and US continue to shrink, the emphasis on SWaP-C continues to strengthen. Military forces require smart weapons capable of precision strike, with a priority on safety. System manufacturers understand these requirements and limitations, and in response, develop miniaturised systems and components and also aim to consolidate these, into a single miniaturised solution. The growth of remotely operated aircraft, offers an ever present need for better, cheaper imaging systems. In general, sensors and seekers tend to be the biggest contribution to the cost and weight of an aircraft. Often, multiple imaging systems are needed dependent on the operational requirements. In this thesis, a novel dual field-of-view imaging system/seeker is proposed, which uses a single imaging sensor to superimpose both a wide field-of-view and a narrow field-of-view image of the same scene, co-boresighted. This allows multiple operational requirements to function simultaneously. The wide field-of-view allows for continuous monitoring and surveillance of an area, whilst the narrow field-of-view enables target detection, identification and tracking capabilities. Secondly, this thesis proposes a novel image separation technique to facilitate the separation of the superimposed imagery, using only the geometric relationship between the two different field-of-views. The separation technique is then extended to operate over sequential frames (i.e. video), and to function with fixed cameras that exhibit (un)desired camera motions, such as vibrations or "jitter". The image quality of the separation technique is broadly analysed over a range of images with varying image characteristics and properties. A novel image quality metric (IQM) was also proposed in this thesis, and was used to analyse the image quality of the recovered images, and its performance compared to already available IQMs. Finally, the separation technique is enhanced to operate with motion cameras, which exhibit motions such as pan, tilt, zoom and rotate etc. The separation technique, in most cases, was found to provide image recovery, comparable to current image enhancement techniques, and moreover, found to be far more robust to errors in registration, compared to current techniques. Initial hardware designs for the dual field-of-view imaging system, designed in conjunction with Prof. Andy Harvey from the University of Glasgow and Dr. James Babbington from Qioptiq Ltd., a lens design and manufacturing company, has also been presented

Aeronautical engineering: A continuing bibliography with indexes (supplement 251)

This bibliography lists 526 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical Engineering: A special bibliography with indexes, supplement 67, February 1976

This bibliography lists 341 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1976

Management: A continuing bibliography with indexes

This biliography lists 919 reports, articles, and other documents introduced into the NASA scientific and technical information system in 1981

Aeronautical Engineering: A continuing bibliography with indexes (supplement 207)

This bibliography lists 484 reports, articles and other documents introduced into the NASA scientific and technical information system in November 1986

Aeronautical engineering: A continuing bibliography with indexes (supplement 271)

This bibliography lists 666 reports, articles, and other documents introduced into the NASA scientific and technical information system in October, 1991. Subject coverage includes design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Aeronautical Engineering: A special bibliography with indexes, supplement 87

This bibliography lists 368 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1977

Sliding Mode Control

The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area

Technology 2003: The Fourth National Technology Transfer Conference and Exposition, volume 2

Proceedings from symposia of the Technology 2003 Conference and Exposition, Dec. 7-9, 1993, Anaheim, CA, are presented. Volume 2 features papers on artificial intelligence, CAD&E, computer hardware, computer software, information management, photonics, robotics, test and measurement, video and imaging, and virtual reality/simulation