Richa Negi

A comparative study of PID tuning methods using anti-windup controller

To study of first-order plus dead times, proportional-integral-differential(PID)Controllers is investigated. PID Controller uses different integral wind-up strategies. The integral wind-up is a phenomenon that occurs in the presence of a saturation of the process input. The controller still saturates due to integral form and this generally leads to large over shoots and settling times. To avoid this saturation, many different anti-windup strategies have been suggested. The approach is based on the combined use of back-calculation and conditional integration anti-windup techniques.

Stability Analysis of 2D Discrete Linear System Described by the Fornasini-Marchesini Second Model with Actuator Saturation

This paper proposes a novel antiwindup controller for 2D discrete linear systems with saturating controls in Fornasini-Marchesini second local state space (FMSLSS) setting. A Lyapunov-based method to design an antiwindup gain of 2D discrete systems with saturating controls is established. Stability conditions allowing the design of antiwindup loops, in both local and global contexts have been derived. Numerical examples are provided to illustrate the applicability of the proposed method.

Delay-dependent stability criterion for uncertain discrete time systems in presence of actuator saturation:

In this paper, the idea of triple Lyapunov functional is applied for controller design of discrete time systems subjected to various nonlinearities like actuator saturation, time varying delay and uncertainties. The performance of the system considered has been examined using H∞ technique in presence of external disturbance. A novel augmented triple Lyapunov-Krasovskii functional is applied with reciprocal convex approach to achieve the stability conditions, which are based on Linear Matrix Inequality. Saturation nonlinearity is tackled using less conservative convex hull method. Numerical examples are provided to illustrate the effectiveness of the proposed criterion.

Sliding mode controller design using PID sliding surface for half car suspension system

The aspiration for this paper is to analyze a new approach in nonlinear controller design for half car suspension system which is a multi input multi output (MIMO) system. The controller design for this system is based on sliding mode control (SMC) using proportional-integral-derivative (PID) sliding surface. This control scheme improves the ride comfort quality and road handling of the active suspension system for the applications on unpaved street with improvement in chattering effects in control effort. The basic modification made in this paper is in sliding surface designing which is based on PID and same is derived from the developed dynamics equations. By this technique steady state error reduces with improvement in transient response. Stability of the nonlinear system is mathematically proven by Lyapunov theorem. The simulation results of proposed controller shows that the better tracking performance is guaranteed compared to conventional SMC controller.

Stability analysis of linear discrete time system with time varying delay and actuator saturation

This paper considers the problem of asymptotic stability of linear discrete-time system with interval-like time-varying delay subjected to actuator saturation through anti-windup strategies. By using a delay based Lyapunov function, a new criterion for the asymptotic stability of such system is proposed in terms of linear matrix inequalities (LMIs). The proposed technique is illustrated by means of numerical example.

Nonlinear feedback linearization controller design for half car suspension system

This paper investigates the nonlinear controller design of a half car suspension system. The half car suspension system is a multiple-input-multiple-output (MIMO) nonlinear system. The proposed controller design is based on a feedback linearization method. Its prime goal is the coordinated control of ride quality and handling performance which are nowadays challenging for suspension systems, for the applications on unpaved roads. The tracking performance of the proposed control technique in the presence of the deterministic road disturbance has been illustrated using simulation results.

Performance analysis of discrete time systems with input saturation: An LMI-based approach

In this paper a Static anti-windup scheme for discrete time systems to achieve global stability and induced l2 performance is presented. The present approach exploits the structural properties of saturation nonlinearities in greater detail as compared to that of a previously reported approach. The applicability of the proposed criterion is illustrated with an example.

Condition for global stability of continuous time delayed linear system with saturated inputs: LMI based approach

This paper deals with the stabilization of continuous time delayed linear systems subjected to actuator saturation by designing an antiwindup controller. For the closed loop system obtained from the controller with antiwindup and the system with deadzone non-linearity, global stability condition by new sector condition is formulated in LMI form in context of both delay independent and delay dependent approach. The proposed technique has been illustrated with an example showing improved state trajectories by delay independent approach and further improvement by delay dependent approach for different time delays.

An LMI criterion for anti-windup design with global asymptotic stability for continuous-time linear systems

The paper presents the anti-windup design for continuous time linear system. An LMI-based approach with improved sector condition is stated for global asymptotic stability of the continuous time linear system. The proposed technique has been illustrated with an example.

H ∞ control of discrete time delayed systems in presence of actuator saturation

This paper investigates stability analysis of discrete time system subjected to actuator saturation, time varying state delay and external disturbances. An observer based dynamic output feedback approach is used to design H∞ controller for stabilizing this system. The observer and controller gain are calculated from stability conditions that are derived using delay dependent Lyapunov functional based on reciprocal convex approach. A numerical example is also provided to show the effectiveness of the proposed theory.