### Browsing by Author "Levine, William S."

Now showing 1 - 7 of 7

###### Results Per Page

###### Sort Options

Item Design of a Flight Controller for an F14 Aircraft Using the DELIGHT.Mary.Lin Optimization-Based CACSD System.(1985) Fan, Michael K-H.; Walrath, C.D.; Lee, C.; Tits, A.L.; Rimer, M.; Grant, R.; Levine, William S.; ISRItem Development of an Engine Idle Speed and Emission Controller(2005) Nagashima, Masaaki; Levine, William S.; ISRThis paper is focused on idling. An engine model is developed. The engine model includes an airflow dynamics model, a combustion model, a fuel injection model, and a catalytic converter model. These models will be used to compare controllers. The idle controller, air / fuel ratio controller, and the emission controller that Honda uses are installed. The measured data and simulated data are compared to evaluate the accuracy of the model. A linear model is developed by linearizing at nominal points. With this linear model, new controllers are developed and compared to the existing controllers.Item Digital Controller Design for the Pitch Axis of the F-14 Using an H_INFINTY Method.(1989) Levine, William S.; Yang, J.S.; ISRA H_INFINITY based control system design procedure is developed. The basic idea is to produce a controller in which the closed- loop system is designed, via H_INFINITY methods similar to those of Kwakemaak, to be robust with respect to both disturbance rejection and insensitivity to parameter variations. This design algorithm is then applied to design a pitch axis controller for a digitized model of the F -14 aircraft. In this two-degree-of- freedom structure, the controller is designed via our H_INFINITY method. The pre-compensator is used to shape the output response so as to cause the entire system to achieve the desired performance. The robustness of the angle-of-attack step response under large parameter variations is also examined.Item A Levinson-Type Algorithm for A Class of Non-Teoplitz Systems with Applications to Multichannel IIR Filtering(1992) Pan, J.; Levine, William S.; ISRA Levinson-type recursion for a class of non-Teoplitz systems of linear equations is demonstrated. A complete solution is expressed as a linear combination of a partial solution and three auxiliary solutions. The class of systems possesses a special structure in that the coefficient matrices can be partitioned into four block Teoplitz submatrices. The number of multiplications and additions required to compute an n- dimensional solution if O(n2). The recursion is then applied to multichannel IIR filtering. Specifically, a lattice structure is established for linear minimum mean square error predictors having independently and arbitrarily specified numbers of poles and zeros. Next the recursion is used to develop a fast time and order recursive algorithm for ARX system identification, producing parameter estimates of family of ARX models. The algorithm preserves consistency of the well-known recursive least-squares algorithm.Item Techniques for Designing Rotorcraft Control Systems, Final Report(1994) Yudilevitch, G.; Levine, William S.; ISROver the last two and a half years we have been demonstrating a new methodology for the design of rotorcraft flight control systems (FCS) to meet handling qualities requirements. This method is based on multicriterion optimization as implemented in the optimization package CONSOL-OPTCAD (C-O). This package has been developed at the Institute for Systems Research (ISR) at the University of Maryland at College Park. This design methodology has been applied to the design of a FCS for the UH-60A helicopter in hover having the ADOCS control structure. The controller parameters have been optimized to meet the ADS-33C specifications. Furthermore, using this approach, an optimal (minimum control energy) controller has been obtained and trade- off studies have been performed.Item Theoretical and Experimental Study of Order Estimation(1992) Pan, J.; Levine, William S.; ISRWe consider estimation of system order and parameters for ARX systems with martingale difference noise. The order estimation criterion used is the accumulated prediction error (or predictive least-square error) criterion which generates strongly consistent order estimates. High computational load and over- complex (when real data are processed) models are two glaring problems occurring in order estimation. We develop a fast and parallel algorithm for strongly consistent estimation of system order and parameters. This shows that order estimation by minimizing the APE cost function could be performed on-line. We also modify the APE criterion by adding a device for tradeoffs between model complexity and model accuracy. This modification helps to solve the over-complexity problem. Furthermore, we present a simulation study on order estimation to complement the theoretical analysis.Item Two Case Studies in Optimization-Based Computer-Aided Design of Control Systems.(1985) Fan, Michael K-H.; Walrath, C.D.; Tits, A.L.; Nye, W.T.; Rimer, M.; Grant, R.; Levine, William S.; ISRThere have been many approaches proposed for the computer-aided design of control systems. The co-authors of this paper include several strong proponents of a design methodology emphasizing designer's intuition, man-machine interaction and sophisticated optimization techniques. This methodology has been implemented by our group as part of the DELIGHT.Mary.Lin system, an offshoot of Berkeley's DELIGHT systems. A logical way to test this approach to computer-aided design is to apply DELIGHT.Mary.Lin to a number of real control system design problems and see how well it performs. This paper describes just such applications to two control problems supplied by industry. In both cases, the problems had been previously solved by other techniques. Thus, we are able to compare the solution obtained with DELIGHT.Mary.Lin to solutions that are acceptable in actual practice.