Reference Governor Design Research Articles

A reference governor for linear systems with polynomial constraints

The paper considers reference governor design for a class of linear discrete-time systems with constraints given by polynomial inequalities and constant reference commands. For such systems, we propose a novel algorithm to compute the maximal output admissible set. The reference governor solves a constrained nonlinear minimization problem at the initialization and then uses a bisection algorithm at the subsequent time steps. The effectiveness of the method is demonstrated by two numerical examples.

A Reference Governor for Nonlinear Systems With Disturbance Inputs Based on Logarithmic Norms and Quadratic Programming

This note describes a reference governor design for a continuous-time nonlinear system with an additive disturbance. The design is based on predicting the response of the nonlinear system, by the response of a linear model with a set-bounded prediction error, where a state-and-input-dependent bound on the prediction error is explicitly characterized using logarithmic norms. The online optimization is reduced to a convex quadratic program with linear inequality constraints. Two numerical examples are reported.

Scalar Reference Governor for Constrained Maneuver and Shape Control of Nonlinear Multibody Aircraft

A control system for constrained control of a nonlinear multibody aircraft is described which exploits a combination of a scalar reference governor and a Linear Quadratic Integral (LQ-I) controller for maneuver load alleviation, trajectory control and shape control. A nonlinear multibody aircraft model for longitudinal flight is used to develop and validate the control system performance. The scalar reference governor is designed based on the linearized model and ensures that the imposed state and control constraints are satisfied. The mismatch between the linearized model used by the reference governor for prediction and the nonlinear dynamics of the multibody aircraft is accounted for in the reference governor design. The paper demonstrates the feasibility of the adopted control approach, including constraint enforcement, based on the nonlinear model simulations of pitching maneuvers.

An Intelligent Reference Governor for Primary Air Control System in a Circulating Fluidized Bed

In combustion of a circulating fluidized bed, primary air plays a key role in keeping materials fluidized and regulating bed temperature. This report provides a design of reference governor for primary air fans to amend their control commands. That will improve the combustion efficiency via regulating primary air flow rate timely according to the changes of coal feed flow rate and bed temperature. To deal with the large inertia and slow response feature of primary air fans, a rule-based control method was used to design the reference governor. Based on the experiences of technical experts and operation data analysis, an expert rules system with wide coverage range was developed, which composed of the logical relationships between the coal feed flow rate, bed temperature and the primary air flow rate in various operation conditions. Test results show that designed reference governor can improve the control performance of primary air flow rate obviously.

Reference governor design with guarantees of detection for delay variation

The present paper deals with fault tolerant control for linear dynamics with additive disturbances. The control action is generated based on information collected from a redundant, multi-sensors network. Delays that may appear during plant measurements transmission through real communication channels are considered as faults. Depending on presence of delay in feedback loop, different invariant sets can be computed. We show that fault tolerant control can be achieved through invariant sets separation with respect to different delay values. Sets separation is accomplished for specific values of the reference signal. Therefore, we introduce in the loop a reference governor which is designed by a receding horizon technique. Thus, we provide reference signals which practically guarantee fault detection and identification in real time.

Reference governor design for tracking problems with fault detection guarantees

The present paper deals with the reference tracking problem for processes with linear dynamics and multisensor information subject to abrupt sensor faults. A key point for fault tolerance will be the separation between healthy and faulty closed-loop behavior upon a set-characterization approach. This is achieved through set theoretic operations involving the healthy/faulty behavior of residual signals related to the system dynamics. As a main contribution, a reference governor scheme is designed using a receding horizon technique. It is shown that fault detection guarantees can be achieved by appropriate adjusting of the governor's delay/prediction window under mild assumptions on the fault scenario.

Integrated Design of Reference Governor with Preview Control

Integrated Design of Reference Governor with Preview Control

外乱を受ける拘束システムに対するリファレンスガバナの設計法

外乱を受ける拘束システムに対するリファレンスガバナの設計法

Nonlinear tracking control in the presence of state and control constraints: a generalized reference governor

This paper proposes a new approach to reference governor design. As in prior literature, the governor accepts input commands and modifies their evolution so that specified pointwise-in-time constraints on state and control variables are satisfied. The new approach applies to general discrete-time and continuous-time nonlinear systems with uncertainties. It relies on safety properties provided by sublevel sets of equilibria-parameterized functions. These functions need not be Lyapunov functions, and the corresponding sublevel sets need not be positively invariant. Technical conditions that capture the bare essentials of what is needed are identified and the usual desirable properties of reference governors are established. The new approach significantly broadens the class of methods available for constructing the nonlinear function that is required in the implementation of the reference governors. This advantage is illustrated in a nonlinear control problem where off-line, computer-based simulation is the basis for constructing the nonlinear function.