Switched mode systems are defined as those represented by a finite set of linear subsystems and a set of logic rules orchestrating the switching among them. Current Programmable Logic controller (PLCs) and the IEC 611...
Switched mode systems are defined as those represented by a finite set of linear subsystems and a set of logic rules orchestrating the switching among them. Current Programmable Logic controller (PLCs) and the IEC 61131-3 standard allows a systematic design of multi-controller architecture to improve the behavior of such type of industrial systems. This paper describes the implementation of Bumpless Transfer (BT) mechanisms within multi-rate control architecture for switched mode systems. By detecting the system state and the feasible next states, the supervisor decides the control algorithms that are active, in tracking mode or in wait state. The steps to design the complete architecture are presented and experimental results that validate the architecture are shown.
This paper describes an approach for modeling smart grids for wide area control applications. More specifically, it is proposed to model smart grids as a set of interdependent composite networks. A composite network i...
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A novel configuration of two-wheeled robotic vehicle with five degrees of freedom (DOF) is presented in this paper. The vehicle is based on double inverted pendulum system with a unique movable payload actuator to ena...
A novel configuration of two-wheeled robotic vehicle with five degrees of freedom (DOF) is presented in this paper. The vehicle is based on double inverted pendulum system with a unique movable payload actuator to enable lifting the payload to a demanded height. A mathematical model is derived incorporating a friction model and plane inclination angle to give the vehicle the ability to manoeuvre on irregular and inclined terrains. The vehicle model is of multi-input multi-output (MIMO) type with highly nonlinear and coupled nature. A fuzzy logic control approach is developed to control and stabilise the vehicle. Simulations in Matlab Simulink showing a successful control of the system are presented and discussed in the paper.
The focus of this paper is on the co-design of control and communication protocol for the control of multiple applications with unknown parameters using a distributed embedded system. The co-design consists of an adap...
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ISBN:
(纸本)9781467320658
The focus of this paper is on the co-design of control and communication protocol for the control of multiple applications with unknown parameters using a distributed embedded system. The co-design consists of an adaptive switching controller and a hybrid communication architecture that switches between a time-triggered and event-triggered protocol. It is shown that the overall co-design leads to an overall switching adaptive system that has bounded solutions and ensures tracking in the presence of a class of disturbances.
In this article the problem of characterizing sets, described by vector nonlinear inequalities of the form v(x) w, as robustly positively invariant and targets of uniformly ultimate bounded nonlinear systems is invest...
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Despite the fact that several Air Traffic Management (ATM) complexity metrics have been proposed in the past few years, very few of these studies incorporate a control independent intrinsic approach to the problem wit...
Despite the fact that several Air Traffic Management (ATM) complexity metrics have been proposed in the past few years, very few of these studies incorporate a control independent intrinsic approach to the problem with the aim of sustaining trajectory flexibility. This paper proposes the introduction of novel decision making metrics for sustaining user trajectory flexibility. The hypothesis is, if all aircraft apply a flexibility preservation function, complexity may reduce automatically. The functions proposed combine concepts of adaptability, robustness and intrinsic traffic complexity metrics based on Lyapunov exponents. Adaptability is defined as a measure of the ability of the aircraft to change its planned trajectory in response to the occurrence of a disturbance that renders the current planned trajectory infeasible. The Robustness metric is defined as the ability of the aircraft to keep its planned trajectory unchanged in response to the occurrence of disturbances. An Intrinsic complexity measure is used to evaluate the level of disorder with regards to the aircraft trajectory; disorder is defined in this context as the level of consistency in the flow patterns of aircraft and their proximity. A point mass model for multiple aircraft(s) is used to extract the trajectories and computing a form of characterisation of sensitivity and interdependencies of a set of aircraft trajectories. Lyapunov exponents are used to compute this measure. The main contribution of this paper will be to test the hypothesis by combining the complexity metrics described above. Different operational scenarios are simulated using a airspace environment developed in MATLAB which shows how well the traffic is structured by varying the metrics defined. The simulation shows the efficacy of the metrics to alleviate complexity in a heavily congested airspace.
A complete flight control scheme with detailed design methodology is proposed for an indoor miniature coaxial helicopter with fixed collective pitch. To avoid system complexity and the problem of minimum phase control...
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ISBN:
(纸本)9781467313971
A complete flight control scheme with detailed design methodology is proposed for an indoor miniature coaxial helicopter with fixed collective pitch. To avoid system complexity and the problem of minimum phase control, the helicopter dynamic model is decomposed into two cascaded subsystems: an inner one for attitude and heading control and the outer one for trajectory control. H-infinity control technique and robust and perfect tracking method are used to respectively design the inner- and outer-loop controllers. By using the so-called asymptotic time-scale and eigenstructure assignment approach, the design process becomes very systematic and effective. The performance of the autonomous flight control system has been successfully validated in actual flight tests.
Adaptation is a fundamental characteristic of sensory processing. It enables sensory neurones to map efficiently the extensive range of environmental signals onto their limited dynamic range in order to prevent satura...
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ISBN:
(纸本)9780889869097
Adaptation is a fundamental characteristic of sensory processing. It enables sensory neurones to map efficiently the extensive range of environmental signals onto their limited dynamic range in order to prevent saturation and to maximize the amount of information collected. This paper presents a novel two-step approach for identifying both the nonlinear dynamical model and the time evolution of the gain of a self-adaptive sensory system based on experimental data. The first step involves estimating a set of fixed-parameter models which are used to determine the underlying stimulus-invariant model structure and the set of parameters that change during adaptation. Subsequently, the inverse problem of estimating the time evolution of these parameters during adaptation can be formulated as an infinite-dimensional nonlinear constrained optimisation problem where the constraint is represented by the 'forward' time-invariant dynamical model derived in the first step. The gain function is estimated by solving an approximate finite-dimensional optimization problem derived using orthogonal Battle-Lemarie scaling basis functions. The applicability of the proposed approach is demonstrated through numerical simulation and using experimental data consisting of intracellular voltage responses recorded from fly photoreceptors subjected to light patterns over a wide range of luminance levels.
This paper addresses robust control and scheduling codesign for networked embedded controlsystems (NECS) with uncertain but interval-bounded time-varying computation and communication delays. The NECS is modeled as a...
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ISBN:
(纸本)9781467320658
This paper addresses robust control and scheduling codesign for networked embedded controlsystems (NECS) with uncertain but interval-bounded time-varying computation and communication delays. The NECS is modeled as a discretetime switched linear system with polytopic uncertainty. A robust receding-horizon control and scheduling problem with a quadratic performance criterion is introduced and solved based on the concept of (relaxed) dynamic programming. Closed-loop stability is guaranteed a priori by imposing stability constraints formulated as linear matrix inequalities. The effectiveness of the proposed modeling and synthesis methods is evaluated for networked embedded control of a set of pendulums. Notably, the proposed strategy is generally applicable to discrete-time switched linear systems with polytopic uncertainty.
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