Robust integrated autopilot/autothrottle design using constrained parameter optimization

A multivariable control design method based on constrained parameter optimization was applied to the design of a multiloop aircraft flight control system. Specifically, the design method is applied to the following: (1) direct synthesis of a multivariable 'inner-loop' feedback control system based on total energy control principles; (2) synthesis of speed/altitude-hold designs as 'outer-loop' feedback/feedforward control systems around the above inner loop; and (3) direct synthesis of a combined 'inner-loop' and 'outer-loop' multivariable control system. The design procedure offers a direct and structured approach for the determination of a set of controller gains that meet design specifications in closed-loop stability, command tracking performance, disturbance rejection, and limits on control activities. The presented approach may be applied to a broader class of multiloop flight control systems. Direct tradeoffs between many real design goals are rendered systematic by this method following careful problem formulation of the design objectives and constraints. Performance characteristics of the optimization design were improved over the current autopilot design on the B737-100 Transport Research Vehicle (TSRV) at the landing approach and cruise flight conditions; particularly in the areas of closed-loop damping, command responses, and control activity in the presence of turbulence

Performance Evaluation of PID Controller for an Automobile Cruise Control System using Ant Lion Optimizer

This paper considers the design and performance evaluation of PID controller for an automobile cruise control system (ACCS). A linearized model of the cruise control system has been studied as per the dominant characteristics in closed loop system. The design problem is recast into an optimization problem which is solved using Ant Lion Optimization (ALO). The transient performance of proposed ACCS i.e., settling time, rise time, maximum overshot, peak time and steady state error are investigated by step input response and root locus analysis. To show the efficacy of the proposed algorithm over a state space method, classical PID, fuzzy logic, genetic algorithm, a comparison study is presented by using MATLAB/SIMULINK. Furthermore, the robustness of the system is evaluated by using bode analysis, sensitivity, complimentary sensitivity and controller sensitivity. The results indicate that the designed ALO based PID controller for ACCS achieves better performance than other recent methods reported in the literature.This paper considers the design and performance evaluation of PID controller for an automobile cruise control system (ACCS). A linearized model of the cruise control system has been studied as per the dominant characteristics in closed loop system. The design problem is recast into an optimization problem which is solved using Ant Lion Optimization (ALO). The transient performance of proposed ACCS i.e., settling time, rise time, maximum overshot, peak time and steady state error are investigated by step input response and root locus analysis. To show the efficacy of the proposed algorithm over a state space method, classical PID, fuzzy logic, genetic algorithm, a comparison study is presented by using MATLAB/SIMULINK. Furthermore, the robustness of the system is evaluated by using bode analysis, sensitivity, complimentary sensitivity and controller sensitivity. The results indicate that the designed ALO based PID controller for ACCS achieves better performance than other recent methods reported in the literature

Decoupled controllers for power systems

Imperial Users onl

Observer theory and control system design

Imperial Users onl

Multi-objective LQR with Optimum Weight Selection to Design FOPID Controllers for Delayed Fractional Order Processes

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.An optimal trade-off design for fractional order (FO)-PID controller is proposed in this paper with a Linear Quadratic Regulator (LQR) based technique using two conflicting time domain control objectives. The deviation of the state trajectories and control signal are automatically enforced by the LQR. A class of delayed FO systems with single non-integer order element has been controlled here which exhibit both sluggish and oscillatory open loop responses. The FO time delay processes are controlled within a multi-objective optimization (MOO) formulation of LQR based FOPID design. The time delays in the FO models are handled by two analytical formulations of designing optimal quadratic regulator for delayed systems. A comparison is made between the two approaches of LQR design for the stabilization of time-delay systems in the context of FOPID controller tuning. The MOO control design methodology yields the Pareto optimal trade-off solutions between the tracking performance for unit set-point change and total variation (TV) of the control signal. Numerical simulations are provided to compare the merits of the two delay handling techniques in the multi-objective LQR-FOPID design, while also showing the capability of load disturbance suppression using these optimal controllers. Tuning rules are then formed for the optimal LQR-FOPID controller knobs, using the median of the non-dominated Pareto solution to handle delays FO processes

Application of modern control and nonlinear estimation techniques

Control and nonlinear estimation techniques applied to optimal guidance of low thrust spacecraft, planetary soft landings, and feedback systems desig

Robust decentralized control of power systems through excitation systems and thyristor controlled series capacitors

The objective of this work is robust decentralized control of power systems through excitation systems and Thyristor Controlled Series Capacitors (TCSC). Hence the dissertation consists of two parts. In the first part an algorithm for the design of nonlinear decentralized excitation control is developed based on a feedback linearization technique. Feedback linearization technique is applied in excitation control of each generator to obtain an interconnected system where subsystems have linear system matrices and interconnections are represented by nonlinear terms. Different ways of achieving decentralization are investigated: (1) linear robust control combined with observer decoupled state space; (2) disturbance accommodation control. While linear robust control guarantees the subsystem\u27s stability when the interconnection terms are bounded within certain values, disturbance accommodation control is based on linear models of the interconnection terms. Nonlinear simulations are performed on a three-machine nine-bus power system. The simulation results demonstrate the effectiveness of the proposed methodologies.;In the second part, indices for control signal selection and mode effectiveness and interaction are developed. They are applied in Thyristor Controlled Series Capacitor damping control, which is to improve inter-area oscillation damping over a range of operating conditions, for evaluating local signals.;Two case studies are performed to explain and demonstrate the effectiveness of the proposed methodologies. The first power system is the two-area four-machine inter-area oscillation benchmark system. The second is the western U.S. power system (WSCC).;The uncertainty shown in the case studies in this dissertation are variations of load conditions. It can also be variations of topologies. The damping controller proposed in this dissertation is to use local measurement as input signals. Local measurements can be obtained by phasor measurement units (PMU). The feasibility of these control schemes using PMU should be investigated using discrete control techniques. Meanwhile, the measurement errors, control signal delays are not considered in this dissertation. Further work can take above factors into consideration. (Abstract shortened by UMI.)