Model Reference Adaptive Control Design Research Articles

An Auto-Pilot System Design Using Reduced Order Model Reference Adaptive Control

In this paper, the singularly-perturbed design of an auto-pilot system of a high speed fighter aircraft, for the same authors (1985), is modified. The previous suboptimal design based on singular perturbation technique was proper only for aircraft operation near its nominal flight conditions. The new proposed adaptive design would be adequate for all possible changes of aircraft dynamics. The plant with varying parameters, representing aircraft, is controlled to behave nearly similar to a chosen first order reference model. The proposed discrete model reference adaptive control design uses an adaptive algorithm of Suzuki and Takashima (1978), based on augmented error signal concept and Popov's hyperstability theorem. Computer simulation results are presented to demonstrate the usefulness of the proposed design.

A stable adaptive control design for discrete plants with unmodelled dynamics

This paper presents a simple discrete model reference adaptive control design which maintains stability around the equilibrium of the tracking error in the presence of unmodelled dynamics. Only a weak a priori knowledge (namely, upper bounds of the absolute value of the unmodelled parameters and orders of the unmodelled dynamics) is required for the implementation. The adaptive controller has an additional parameter to protect the scheme against instability.

Model Reference Adaptive Control of Feed Force in Turning

This paper applies the discrete-time single-input/single-output Model Reference Adaptive Control (MRAC) design technique of Landau and Lozano to the problem of regulating feed force on a lathe under varying cutting conditions. A first-order model is used to represent the relationship between feed force and the control input (feedrate). The MRAC scheme is implemented on a multi-microprocessor based computer-numerical-control system. Results of applying various algorithms derived from the MRAC design technique are presented.

Discrete model-reference adaptive control using only input and output measurements

A globally stable discrete model-reference adaptive controller design using only input and output measurements is presented. The rejection of both measurable and unmeasurable load disturbances is included in the adaptive system. The use of state-variable filters ensures that the basic scheme is applicable to a process with moderate measurement noise. With large measurement noise, an extended scheme using the technique of instrumental variable is introduced. The performance of these designs is substantiated by simulation.

Unification of discrete time explicit model reference adaptive control designs

Various discrete time explicit MRAC designs based on stability considerations are presented from a unified point of view. A general structure and a design procedure are given, which contain as particular cases various possible designs. Some of these designs have been already given in the literature but some are new. The general structure considered removes some of the restrictions encountered in previous designs and solves the important problem of independent specification of tracking and regulation objectives. The proof of boundedness of the control variables is also given. Simulations are included in order to evaluate the various designs in a deterministic environment.

An extension of hyperstable adaptive control to non-minimum phase systems

In this paper the model reference adaptive control design of Suzuki and Takashima (1978) is extended to permit application to non-minimum phase systems. It is shown that the control system of Suzuki and Takashima does not explicitly include an a priori bounded plant input-output assumption necessary for their proof of asymptotic hyperstability. Although not stated explicitly, the same assumption of bounded input to the linear block is also a necessary condition for Landau' s theorems on hyperstability which have been used as the basis for many adaptive control investigations.

RECENT ADVANCES IN ADAPTIVE CONTROL

Abstract A survey of the design techniques and applications of adaptive control has been presented. Two approaches to adaptive control have been considered, with greater emphasis on the model reference adaptive systems including the new ideas introduced in this area during the past decade. A typical example of the design of a two-level model-reference adaptive controller for a continuous stirred tank reactor is discussed in detail. A number of other examples with applications are also briefly presented, and a list of references is given for further details.