Space vehicles have become increasingly complex in recent years, and the number of missions has multiplied as a result of extending frontiers in the exploration of our planetary system and the universe beyond. The advancement of automatic control in aerospace reflects these developments. Key areas covered in these proceedings include: the size and complexity of spacecrafts and the increasingly stringent performance requirements to be fulfilled in a harsh and unpredictable environment; the merger of space vehicles and airplanes into space planes to launch and retrieve payloads by reusable winged vehicles; and the demand to increase space automation and autonomy to reduce human involvement as much as possible in manned, man-tended and unmanned missions. This volume covers not only the newly evolving key technologies but also the classical issues of guidance, navigation and control.
An important, successful area for control systems development is that of state-of-the-art aeronautical and space related technologies. Leading researchers and practitioners within this field have been given the opportunity to exchange ideas and discuss results at the IFAC symposia on automatic control in aerospace. The key research papers presented at the latest in the series have been put together in this publication to provide a detailed assessment of present and future developments of these control system technologies.
Satellites are used increasingly in telecommunications, scientific research, surveillance, and meteorology, and these satellites rely heavily on the effectiveness of complex onboard control systems. This 1997 book explains the basic theory of spacecraft dynamics and control and the practical aspects of controlling a satellite. The emphasis throughout is on analyzing and solving real-world engineering problems. For example, the author discusses orbital and rotational dynamics of spacecraft under a variety of environmental conditions, along with the realistic constraints imposed by available hardware. Among the topics covered are orbital dynamics, attitude dynamics, gravity gradient stabilization, single and dual spin stabilization, attitude maneuvers, attitude stabilization, and structural dynamics and liquid sloshing.
The study of nonlinear phenomena in aviation and aerospace includes developments in computer technology and the use of nonlinear mathematical models. Nonlinearities are a feature of aircraft dynamics and flight control systems and need to respond to achieve stability and performance. This multiauthor volume comprises selected papers from the confer
The advent of very compact, very powerful digital computers has made it possible to automate a great many processes that formerly required large, complex machinery. Digital computers have made possible revolutionary changes in industry, commerce, and transportation. This book, an expansion and revision of the author's earlier technical papers on this subject, describes the development of automation in aircraft and in the aviation system, its likely evolution in the future, and the effects that these technologies have had -- and will have -- on the human operators and managers of the system. It suggests concepts that may be able to enhance human-machine relationships in future systems. The author focuses on the ability of human operators to work cooperatively with the constellation of machines they command and control, because it is the interactions among these system elements that result in the system's success or failure, whether in aviation or elsewhere. Aviation automation has provided great social and technological benefits, but these benefits have not come without cost. In recent years, new problems in aircraft have emerged due to failures in the human-machine relationship. These incidents and accidents have motivated this inquiry into aviation automation. Similar problems in the air traffic management system are predicted as it becomes more fully automated. In particular, incidents and accidents have occurred which suggest that the principle problems with today's aviation automation are associated with its complexity, coupling, autonomy, and opacity. These problems are not unique to aviation; they exist in other highly dynamic domains as well. The author suggests that a different approach to automation -- called "human-centered automation" -- offers potential benefits for system performance by enabling a more cooperative human-machine relationship in the control and management of aircraft and air traffic.
The 1990s are proving to be a very exciting p&iod for high angular resolution astronomy. At radio wavelengths a combination of new array instruments and pow erful imaging algorithms have generated images of unprecedented resolution and quality. In the optical and infrared, the great technical difficulties associated with constructing separated-aperture interferometers have been largely overcome, and many new instruments are now operating or are being developed. As these pro grams start to produce observational results they will be able to draw extensively on the experience gained by the radio-interferometry community. Thus it seemed that the time was ripe for a meeting which would bring together workers from all wavelength ranges to discuss the details of the science and art of "Very High Angular Resolution Imaging" . While the main emphasis of Symposium No. 158 was on high resolution tech niques from the radio, mm-wave, infrared and optical bands, it also provided an opportunity for presentation of astronomical results from these techniques. As well as giving our colleagues from the Northern Hemisphere a break from midwinter, the location of the Symposium in Australia recognised the continuing development of astronomical interferometry in this country, especially the recent completion of the Australia Telescope radio array, and the progress toward com missioning of the Sydney University Stellar Interferometer. A number of the par ticipants visited these instruments during the post-symposium tour.
