00000nam 2200000zi 4500 9.884937 CaOODSP 20221107171010 m o d f cr cn||||||||| 200221s1976 onca ob f000 0 eng d CaOODSP eng rda CaOODSP Co24-442/1976E-PDF Hughes, P. C. (Peter Carlisle), 1940- author. Nonlinear attitude control of very flexible communication satellites / by P.C. Hughes, Tarek M. Abdel-Rahman. [Ottawa] : [Department of Communications], 1976. 1 online resource (ii, 36 pages, 23 unnumbered pages) : illustrations text txt rdacontent computer c rdamedia online resource cr rdacarrier "DSS contract 0SU5-0103." "July, 1976." Digitized edition from print [produced by Innovation, Science and Economic Development Canada]. Some pages rotated in this copy. Includes bibliographical references (pages 34-36). "The effect of structural flexibility on two nonlinear attitude control systems (namely, a pseudo-rate control system, and an integral-pulse-frequency control system) is investigated. The parameters of each modulator are chosen in accordance with standard design considerations to give an equivalent linearized rigid spacecraft response. The first unconstrained natural mode of vibration is used to represent the structural flexibility in the dynamic model of the spacecraft. A first order time lag is used to model the essential characteristic of the sensor. The state space region of interest is then defined, and the responses of both control systems are simulated on the NRC EAI 690 hybrid computer. A large number of initial conditions were studied. Simulation results show that in the case of the pseudo-rate controller, the state space region of acceptable performance shrinks seriously for many combinations of structural flexibility and sensor parameters. In contrast, no shrinkage at all occurred for the integral-pulse-frequency controller"--Summary, page 3. Issued also in print format. Artificial satellites Attitude control systems. Artificial satellites in telecommunication. Flexible structures. Satellites artificiels Systèmes de commande d'orientation. Satellites artificiels dans les télécommunications. Structures flexibles. Canada. Department of Communications. University of Toronto. Institute for Aerospace Studies. PDF 2.47 MB https://publications.gc.ca/collections/collection_2020/isde-ised/Co24/Co24-442-1976-eng.pdf