Valery D. Yurkevich

Design of nonlinear control systems with the highest derivative in feedback

Regularly and Singularly Perturbed Systems Design Goal and Reference Model Methods of Control System Design Under Uncertainty Design of SISO Continuous-Time Control Systems Advanced Design of SISO Continuous-Time Control Systems Influence of Unmodeled Dynamics Realizability of Desired Output Behavior Design of MIMO Continuous-Time Control Systems Stabilization of Internal Dynamics Digital Controller Design Based on Pseudo-Continuous Approach Design of Discrete-Time Control Systems Design of Sampled-Data Control Systems Control of Distributed Parameter Systems.

DESIGN OF ANALOG AND DIGITAL AIRCRAFT FLIGHT CONTROLLERS BASED ON DYNAMIC CONTRACTION METHOD

In the paper the feasibility of the Dynamic Contraction Method for the design of the aircraft motion analog and digital controllers is studied. The control task is formulated as a tracing problem for Euler angles, where decoupled output transients are accomplished in spite of incomplete information about varying parameters of the system and external disturbances. A resulting output feedback continuous-time controller has a simple form of a combination of three low-order linear dynamical systems and a matrix whose entries depend nonlinearly on certain known process variables. The resulting continuous-time controller is then digitally redesigned. The pseudo - continuous - time model of a control loop with a pure time delay is used to calculate parameters of a digital controller.

PWM current controller design for multi-level DC-DC converter via singular perturbation technique

The problem of current regulation for a multilevel DC-DC converter is discussed. The paper addresses PI control with an additional low-pass filtering and a high-frequency pulse-width modulation (PWM) in control loop. The problem of controller design is reduced to the continuous-time controller design based on the Filippovs average model of the multi-level DC-DC converter. The design methodology of PI controller via singular perturbation technique is presented where two-time-scale motions are artificially induced in the closed-loop system. The method of singular perturbations is used throughout the paper. Numerical simulations are included.

PWM Controller Design based on Singular Perturbation Technique: A Case Study of Buck-Boost DC-DC Converter

Abstract The problem of DC voltage regulation for buck-boost DC-DC converter is discussed in presence of resistor load variations and voltage source variations as well. This paper addresses PI control with an additional low-pass filtering and a high-frequency pulse-width modulation (PWM) in control loop. The problem of controller design is reduced to the continuous-time controller design based on Filippovs average model of buck-boost DC-DC converter. The design methodology of cascaded PI controller via singular perturbation technique is used where two-time-scale motions are artificially induced in the closed-loop system. The method of singular perturbations is used throughout the paper. Numerical simulations for buck-boost DC-DC converter are presented.

PI and PID controller design for nonlinear systems in the presence of a time delay via singular perturbation technique

The paper treat a question of proportional-integral and proportional-integral-derivative (PM) controller design for nonlinear same in the presence of a time delay, plants parameter variations, and unknown external disturbances. The design of a universal controller, which is an extension of PI (PID) controller, I discussed as well The presented design methodology guarantees desired output transient performance indices by inducing of two-time-scale motions in the closed loop system. Stability conditions imposed on the fast and slow mode and sufficiently large mode separation rate between fast and slow modes can ensure that the full-order closed-loop nonlinear system achieves the desired properties in such a way that the output transient performances are desired and insensitive to external disturbances and plants parameter variations. The method of singular perturbations is used throughout the paper in order to got explicit expressions for evaluation of the controller parameters. Numerical examples with simulation results are presented.

Design of controller for buck-boost converter

The problem of output regulation with guaranteed transient performances for buck-boost converter with inverting topology is discussed. The fast dynamical controller with the relative highest derivative of output signal in feedback loop is used. Consequently, two-time-scale motions are induced in the closed-loop system. Stability conditions imposed on the fast and slow modes and sufficiently large mode separation rate can ensure that the full-order closed-loop system achieves the desired properties in such a way that the output transient performances are desired and insensitive to external disturbances and parameter variations in the system. The existence of stable limit cycle in the fast motion subsystem gives the robustness of the output transient performances in the presence of external disturbance and parameter uncertainty. The describing function method is used to analyze the existence and parameters of stable limit cycle.

Implementation of Single Feedback Control Loop for Constant Power Regulated Swash Plate Axial Piston Pumps

Abstract Variable displacement pumps are often used in both industrial applications and mobile hydraulic machinery. In such pumps, flow rate is dictated by the system requirements. Mathematical model has been previously developed to simulate the dynamic performance of the electrically controlled constant power regulated swash plate axial piston pump with conical cylinder blocks. The pump is currently equipped with a double negative feedback control loop with an inner control loop to control the position of proportional valve using PID controller. Consequently, the proportional valve distributes the control pressure across the two sides of a control piston that is mechanically attached to the pump swash plate in order to change the pump flow rate. The outer control loop is used to control the pump flow rate in accordance with the system pressure change in order to keep the constant power operation using PD controller. For the convenience of pump constant power operation, PD controller is tuned to keep limited power shocks on the pump drive motor during the transient periods. The selected PD parameters result in relatively reduced settling time. Consequently swash plate steady state vibration appears. Purpose of this paper is to investigate features of the pump performance in view of an alternative control scheme. Counting on the relatively good open loop static characteristics of the proportional valve, a control scheme with a single control feedback loop is proposed to simplify the currently used control scheme. Using such single feedback control loop reduces the pump production cost and leads to have less responsive system that suppresses the steady state vibration of the swash plate. Simulation results are verified experimentally and qualitatively compared with the results when the original control scheme is used. Results are presented and discussed.

Educational Issues of PI-PID Controllers.

Abstract Educational issues of Proportional, Integral (PI) and Proportional, Integral, and Derivative (PID) type controller design in undergraduate course on control, graduate course on control, advanced control topics are discussed. The main attention is devoted to multi-time-scale control systems where PI PID type controllers designed for nonlinear systems in the presence of plant parameter variations and unknown external disturbances based on application of singular perturbation technique which guarantees desired output transient performance.

Robust Digital Controller Design for MIMO Non-Linear Time-Varying Systems

Abstract A control problem in which the control task is formulated for output variables as decoupled tracking with desired output transients is stateted and solved for continuous-time non-linear time-varying MIMO systems under assumption of incomplete information about varying parameters of the system and external disturbances. A continuous-time controller based on the Dynamic Contraction Method is designed for a pseudo-continuous-time model of the control loop with a pure time delay and then Tustin transformation is used to calculate the parameters of a digital controller. In order to increase the sampling period a control law with a compensation of the time delay is used.

PWM speed control of DC motor based on singular perturbation technique

The problem of regulation for a DC motor with autonomous voltage inverter is discussed. The considered control system consists of two feedback loops. In the first one, the armature current control for a DC motor is provided by means of pulse-width modulated control of such autonomous voltage inverter as the H-bridge. In the second one, DC motor speed control is maintained. Proportional-integral (PI) controllers are designed for armature current and motor speed control based on singular perturbation technique such that multi-time-scale motions are artificially induced in the closed-loop system. Multi-time-scale motions analysis allows getting analytical expressions for selection of controller parameters. Simulation results are presented as well.