Single Output Feedback Controller Research Articles

Finite-Time Simultaneous Stabilization for Stochastic Port-Controlled Hamiltonian Systems over Delayed and Fading Channels

In this paper, a finite-time simultaneous stabilization problem is investigated for a set of stochastic port-controlled Hamiltonian (PCH) systems over delayed and fading noisy channels. The feedback control signals transmitted via a communication network suffer from both constant transmission delay and fading channels which are modeled as a time-varying stochastic model. First, on the basis of dissipative Hamiltonian structural properties, two stochastic PCH systems are combined to form an augmented system by a single output feedback controller and then sufficient conditions are developed for the semiglobally finite-time simultaneous stability in probability (SGFSSP) of the resulting closed-loop systems. The case of multiple stochastic PCH systems is also considered and a new control scheme is proposed for the systems to save costs and achieve computational simplification. Finally, an example is provided to verify the feasibility of the proposed simultaneous stabilization method.

Trailer control through vehicle yaw moment control: Theoretical analysis and experimental assessment

This paper investigates a torque-vectoring formulation for the combined control of the yaw rate and hitch angle of an articulated vehicle through a direct yaw moment generated on the towing car. The formulation is based on a single-input single-output feedback control structure, in which the reference yaw rate for the car is modified when the incipient instability of the trailer is detected with a hitch angle sensor. The design of the hitch angle controller is described, including the gain scheduling as a function of vehicle speed. The controller performance is assessed by means of frequency domain and phase plane analyses, and compared with that of an industrial trailer sway mitigation algorithm. In addition, the novel control strategy is implemented in a high-fidelity articulated vehicle model for robustness assessment, and experimentally tested on an electric vehicle demonstrator with four on-board drivetrains, towing two different conventional single-axle trailers. The results show that: (i) the torque-vectoring controller based only on the yaw rate of the car is not sufficient to mitigate trailer instability in extreme conditions; and (ii) the proposed controller provides safe trailer behaviour during the comprehensive set of manoeuvres, thus justifying the additional hardware complexity associated with the hitch angle measurement.

Adaptive Robust Simultaneous Stabilization of Two Dynamic Positioning Vessels Based on a Port-Controlled Hamiltonian (PCH) Model

In this paper, the adaptive robust simultaneous stabilization problem of two ships is studied. Firstly, the water surface three-degree-of-freedom ship models are transformed into port-controlled Hamiltonian (PCH) models. Using a single output feedback controller, the two PCH systems are combined to generate an enhanced PCH system based on Hamiltonian structural attributes. Then, considering the situation with both external interference and structural parameter perturbation in the systems, an adaptive robust output feedback controller is designed to stabilize the two systems simultaneously. Finally, the effectiveness of the controller proposed in this paper is illustrated by a simulation example.

Real-time feedback control of three-dimensional Tollmien-Schlichting waves using a dual-slot actuator geometry

Tollmien-Schlichting (TS) waves are attenuated experimentally using a single-input and single-output feedback control system in real time. On implementing the controller, TS wave growth rates are shown to be suppressed significantly over a noticeably large domain.

Active noise control: Eight decades of research and applications

On January 27, 1933, Paul Lueg submitted his patent application for an active noise control system. In the intervening 80 years, the concept has progressed from simple single-input single-output feedback control systems through to complex MIMO approaches implementing a seemingly endless variety of control algorithms. Academic publications appear to continue at approximately a constant pace over the past decade, with much attention paid to algorithm refinement and development of applications. Commercial successes of active noise control include ANC headset in the aviation and consumer markets, as well as systems installed in passenger vehicle (some of which also incorporating active vibration control systems). This paper will provide a brief historical retrospective on the development of active noise control, and survey the current state of academic research as well as existing and proposed production applications (consumer, aviation, defense, etc.).

Design of output feedback controller for a unified chaotic system

In this paper, the synchronization of a unified chaotic system is investigated by the use of output feedback controllers; a two-input single-output feedback controller and single-input single-output feedback controller are presented to synchronize the unified chaotic system when the states are not all measurable. Compared with the existing results, the controllers designed in this paper have some advantages such as small feedback gain, simple structure and less conservation. Finally, numerical simulations results are provided to demonstrate the validity and effectiveness of the proposed method.

Robust stabilization of uncertain high order systems via smooth output feedback

We investigate the robust stabilization problem for a family of uncertain nonlinear systems with uncontrollable/unobservable linearization. To achieve global robust stabilization using a single output feedback controller, we introduce a rescaling transformation with an appropriate dilation, which turns out to be very effective in dealing with uncertainty of the system. Using this rescaling technique combined with the non-separation principle based design methods (Qian and Lin, 2002a; Yang and Lin, 2003), we develop a robust output feedback control scheme for uncertain nonlinear systems satisfying a homogeneous growth condition. Both a smooth state feedback controller and a homogeneous observer are designed for the rescaled system using only the knowledge of the bounding system rather than the uncertain system itself.

Adaptive Output Feedback Controller for Wind Turbine Generators Using Neural Networks

An adaptive output feedback controller using neural networks for improving the dynamic stability of a wind turbine generator supplying an infinite bus through a transmission line under widely varying conditions is presented. The need for adaptive output feedback comes from the fact that the wind turbine operates over a range of operating points, some of which are unstable; hence, no single output feedback controller gains are sufficient for the entire operating range. Neural networks are used for on-line prediction of the suitable gains for the output controller when the operating point changes. Simulation results are included to demonstrate the performance of the proposed control scheme.

42 Full body kinematics of stumble recovery

This paper investigates a torque-vectoring formulation for the combined control of the yaw rate and hitch angle of an articulated vehicle through a direct yaw moment generated on the towing car. The formulation is based on a single-input single-output feedback control structure, in which the reference yaw rate for the car is modified when the incipient instability of the trailer is detected with a hitch angle sensor. The design of the hitch angle controller is described, including the gain scheduling as a function of vehicle speed. The controller performance is assessed by means of frequency domain and phase plane analyses, and compared with that of an industrial trailer sway mitigation algorithm. In addition, the novel control strategy is implemented in a high-fidelity articulated vehicle model for robustness assessment, and experimentally tested on an electric vehicle demonstrator with four on-board drivetrains, towing two different conventional single-axle trailers. The results show that: (i) the torque-vectoring controller based only on the yaw rate of the car is not sufficient to mitigate trailer instability in extreme conditions; and (ii) the proposed controller provides safe trailer behaviour during the comprehensive set of manoeuvres, thus justifying the additional hardware complexity associated with the hitch angle measurement.

Application of control theory to endocrine regulation and control.

This paper considers some aspects of the application of control theory to endocrine regulation and control. Consideration is given to both the structural and functional aspects of various control concepts and ideas in this context. For single-input, single-output feedback control structures, emphasis is placed on loop gain and its importance in establishing the functional capability of such structures. Examples are given of both functional and nonfunctional feedback structures proposed by endocrinologists. For multi-input, multi-output structures, emphasis is placed on the concept of input and output decoupling, and the possible applicability of these concepts to hormonal control system interrelationships is illustrated. Finally, the possible application of optimal control theory to endocrine regulation and control is illustrated by means of a naive and highly simplified example involving control of the thyroid gland by the pituitary gland, and several surprising and interesting implications are shown to be implicit in the resulting control structure.

A nonlinear discrete system equivalence of integral pulse frequency modulation systems

In this paper a study of the effect of integral pulse frequency modulation (IPFM) on single-input single-output feedback control is attempted. For zero input such systems can be reduced to a nonlinear discrete system. Lagrange stability concepts are used for the stability study of such systems. A step-by-step procedure is devised for the construction of the state trajectories of the IPFM system. This has been applied to a second-order plant where it is shown that instability, asymptotic stability in the large, and asymptotic stability in the Lagrange sense are exhibited by such systems. It is also shown that in IPFM systems, the periodic oscillation that exists depends on the initial state. The equivalence concepts of such systems are reviewed critically, and the limitations of the method are pointed out. Further research in this area of feedback modulation is proposed and discussed.