Abstract
Construction methodology is presented, by which optimal Controllers, Estimators and Compensators can be synthesized for nonlinear discrete time processes. The nonlinearities in both the process and the measurement equations are expanded into Taylor series in the state vector, holding an arbitrary, but consistent level of truncation. Then, both the state conditional probability evolution, and the associated Dynamic Programming Equation can be solved for off line, ahead of time, retaining the same truncation level as that of the process model. This yield non-anticipative control laws that are consistently optimal, i.e., are as close to the optimum as the state models are to the exact ones. In the perfect information case the present controllers are nonlinear feedback-feedforward laws. The feedback part consists of polynomials of the state. The feedforward part includes moments of the process dynamic noise and possible forcing functions. All the gains are known ahead of time. In the fully stochastic situation, algorithms are obtained for on line update of the state conditional probability distribution, as the compensator feeds back various moments of that distribution in real time with all the gains known ahead of time.
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References
Lukes, D. L., “Optimal regulation of nonlinear dynamical systems,”SIAM J. Control, Vol. 7, pp. 75–100. 1969.
Willemstein, A. P., “Optimal regulation of nonlinear dynamical systems on a finite interval,”SIAM J. Control and Optimization, Vol. 15, pp. 1050–1069, 1977.
Bryson, A. E. and Ho, U.-C.,Applied Optimal Control. New York: John Wiley & Sons, 1975.
Hermann, R. and Krener, A. J., “Nonlinear controllability and observability,”IEEE Trans. on Automatic Control, Vol. AC 22, pp. 728–740, 1977.
Fliess, M., “Lie Brackets and optimal nonlinear feebback regulation,”Proc. of the 9th IFAC World Congress, Budapest, Vol. 5, pp. 78–82, 1984.
Fliess, M. and Hazewinkel, M. (eds.),Algebraic Methods in Nonlinear Control Theory, D. Reidel: Dordrecht, 1986.
Beaman, J. J., “Non-linear quadratic Gaussian control,”International Journal of Control, Vol. 39, pp. 343–361, 1984.
Cox, H., “On the estimation of state variables and parameters for noisy dynamic systems,”IEEE Trans. on Automatic Control, Vol. 9, pp. 5–12, 1964.
Jazwinski, A. H.,Stochastic Processes and Filtering Theory, New York: Academic Press, 1970.
Blankenship, G. L., Lin, C.-H. and Marcus, S. I., “Asymptotic expansions and Lie algebras for some nonlinear filtering problems,”IEEE Trans. on Automatic Control, Vol. AC-28, 1983.
Tse, E. and Bar Shalom, Y., “Adaptive dual-control for stochastic nonlinear systems with free end time,”IEEE Trans. on Automatic Control, Vol. AC 20, pp. 670–675, 1975.
Casler, R. J., “Dual control guidance strategy for homing interceptors taking angle-only measurements,” it AIAA J. Guidance & Control, Vol. 1, pp. 63–70, 1978.
Speyer, J. L. and Hull, D. G., “Estimation enhancement by trajectory modulation for homing missiles,” {jtProc. of the American Control Conference}, Arlington, VA., pp. 978–984, 1982.
Bellman, R. E.,Adaptive Control Processes: A Guided Tour. Princeton, NJ: Princeton University Press, 1961.
Shefer, M.,Estimation and Control with Cubic Nonlinearities, Ph.D. Thesis, Standford, CA: Stanford University, 1983.
Shefer, M. and Breakwell, J. V., “Estimation and control with cubic nonlinearities,”Journal of Optimization Theory and Applications, Vol. 53, pp. 1–7, 1987.
Shefer, M. and Breakwell, J. V., “Perturbation guidance laws for perfect information interceptors with symmetrical nonlinearities,”AIAA Journal of Guidance, Control and Dynamics, Vol. 9, pp. 32–36, 1986.
Shefer, M. and Breakwell, J. V., “An opitmal nonlinear compensator,”Proc. of the 27th IEEE Conference on Decision and Control, Austin, Texas, pp. 466–468, 1988.
Shefer, M., “Discrete optimal tracking with prescribed disturbances,”AIAA Journal of Guidance, Control and Dynamics, Vol. 11, pp. 371, 1988.
Shefer, M., “The intrinsic approach to space robotic manipulators,”Proc. of the AIAA Guidance, Navigation and Control Conference, Portland, Oregon, 1990.
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Shefer, M., Breakwell, J.V. Optimal compensators for nonlinear analytic discrete time processes. Dynamics and Control 5, 37–54 (1995). https://doi.org/10.1007/BF01968534
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DOI: https://doi.org/10.1007/BF01968534