## About

75

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1,147

Citations

Citations since 2016

Additional affiliations

January 2008 - present

January 2007 - December 2008

**Queen Mary, University of London**

## Publications

Publications (75)

In the face of a shortage of engineering and technical skills, degree apprenticeships are emerging as an important feature of the education and training landscape and the Government’s ambitions for their future are substantial. The Skills Minister the Rt Hon Anne Milton MP sees them as a challenge to university as the “default” post-school pathway...

The profound shortage in the engineering skills pipeline is well documented and so the EPC enthusiastically welcomes the development and promotion of degree apprenticeships. The whole engineering sector shares the hope that degree apprenticeships will prove a significant channel for tomorrow's engineers to gain the skills, qualifications, knowledge...

This paper studies the optimal control of a sea wave energy converter (WEC). A linear optimal controller is designed for the WEC to maximise the energy output. Rather than regulating states and control inputs as a conventional optimal controller normally does, the proposed optimal controller aims to maximise the energy output. The maximum output ad...

The problem of formation control of unmanned aerial vehicles is tackled. The control laws were developed based on two methods of formation control. These are the virtual leader formation control method and the non-hierarchical method. A decentralised controller was used, so as to distribute the formation keeping effort among the agents. The virtual...

We consider networks of time-delayed diffusively coupled systems and relate conditions for synchronization of the systems in the network to the topology of the network. First we present sufficient conditions for the solutions of the time-delayed coupled systems to be bounded. Next we give conditions for local synchronization and we show that the va...

In this paper we study the formation control problem for car-like robots which may be viewed as a more general type of robots than the usually considered unicycle type robots. We develop a controller using the backstepping approach and give conditions solving the formation control problem as well as the coordination control problem. We also present...

In this paper, we consider the problem of distributed formation control for a group of unicycle robots. We propose a control algorithm that solves the formation control problem in that it ensures that robots create a desired time-varying formation shape while the formation as a whole follows a prescribed trajectory. Moreover, we show that it is als...

In this article, the formation control problem for unicycle mobile robots is studied. A distributed virtual structure control strategy with mutual coupling between the robots is proposed. The rationale behind the introduction of the coupling terms is the fact that these introduce additional robustness of the formation with respect to perturbations...

This paper addresses the problem of formation control of groups of unicycle robots with possibly time-varying formation shapes. To solve the problem, we propose two simple distributed formation control algorithms based on the virtual structure approach. We prove exponential convergence of error variables to the origin and illustrate the behavior of...

In this paper we consider the stabilizability of nonlinear dynamical systems via time-delayed state and output feedback control. Based on an eigenvalue optimisation approach in combination with a continuation argument and a result characterising properties of the optimum eigenvalue configurations, we obtain explicit expressions for stabilizability...

We study the stabilizability of a linear controllable system using state derivative feedback control. As a special feature the stabilized system may be fragile, in the sense that arbitrarily small modelling and implementation errors may destroy the asymptotic stability. First, we discuss the pole placement problem and illustrate the fragility of st...

In this paper we consider the stabilisability of dynamical systems via time-delayed state and output feedback control. Based on an eigenvalue optimisation approach in combination with a continuation argument and a result characterising properties of the optimum eigenvalue configurations, we obtain explicit expressions for stabilisability boundaries...

This research investigates the development of a stable adaptive model predictive control approach for a constrained nonlinear system. The method is well- known as multistep Newton-type control strategies however, the formulation here differs from the original one. The nonlinear physical equations of the system are extracted considering all possible...

This investigation presents 1 degree of freedom (1DOF) dynamic modelling of an experimental aerodynamic test rig, a twin rotor multi-input–multi-output system (TRMS) using analytical as well as empirical approaches. The TRMS is a highly nonlinear system which can be considered as an experimental model of a complex air vehicle. Such vehicles are req...

We study the stabilizability of a linear controllable system using state derivative feedback control. As a special feature the stabilized system may be fragile, in the sense that arbitrarily small modelling and implementation errors may destroy the asymptotic stability. First, we discuss the pole placement problem and illustrate the fragility of st...

Synchronization of complex/chaotic systems is reviewed from a dynamical control perspective. It is shown that the notion of
an observer is essential in the problem of how to achieve synchronization between two systems on the basis of partial state
measurements of one of the systems. An overview of recent results on the design of synchronizing syste...

This paper revisits some distributed update laws for power control in ad-hoc wireless networks that have previously been proposed in the literature. After having recast these update laws in a framework of so-called certainty equivalence and proportional-integral (PI) control, it is shown that there are problems with stability and feasibility in one...

In this paper we consider the anticipating synchronization of chaotic time-delayed Lur'e-type systems in a master-slave setting. We introduce three scenarios for anticipating synchronization, and give sufficient conditions for the existence of anticipating synchronizing slave systems in terms of linear matrix inequalities. The results obtained are...

The problem of stabilization of unknown steady states of chaotic systems by means of linear controllers is studied. A complete solution of the problem is given for the case of state feedback stabilization. For the case of output feedback stabilization, some partial results are given. The paper shows that the control theoretic concepts of controllab...

Sigma delta modulation is a popular form of A/D and D/A conversion. This nonlinear device exhibits a high degree of complex nonlinear behaviour, including chaotic dynamics. One of the main unsolved problems in the theory of sigma delta modulation concerns the ability to analytically derive conditions for the boundedness of solutions of a high order...

The importance of using the physical structure of a system for solving control problems is illustrated by means of the input-output decoupling problem with stability for Hamiltonian systems.

Sigma delta modulation is a popular form of A/D and D/A conversion. This nonlinear device exhibits a high degree of complex nonlinear behaviour, including chaotic dynamics. One of the main unsolved problems in the theory of sigma delta modulation concerns the ability to analytically derive conditions for the boundedness of solutions of a high order...

In this paper we study the problem of stabilisation of unknown steady states of chaotic systems using linear controllers, which has recently received some attention in the physics literature. A complete characterisation of stabilising linear state feedback controllers of minimal dimension is given. For the case of output feedback stabilisation, som...

This paper studies the synchronous motions (motions for which each of the buses moves with a constant velocity) of a car-following model for a circular bus route. Different types of synchronous motion are identified, and their local stability is studied using root locus methods. The bifurcations of synchronous motions are described, and simulation...

This note revisits a car-following model of road traffic on a circular route that was studied in recent literature, and improves a stability result for steady-state flows that was obtained in this literature. It will be shown through a counter example that the stability bound obtained in the literature only gives a sufficient condition for stabilit...

A method is described for the synchronization of nonlinear discrete-time dynamics. The methodology consists of constructing observer–receiver dynamics that exploit at each time instant the drive signal and buffered past values of the drive signal. In this way, the method can be viewed as a dynamic reconstruction mechanism, in contrast to existing s...

Studies the synchronous motions (motions for which each of the buses moves with a constant velocity) of a car-following model for a circular bus route. Different kinds of synchronous motion are identified, and their local exponential stability is studied using root locus methods

Studies the synchronous motions (motions for which each of the buses moves with a constant velocity) of a car-following model for a circular bus route. Different kinds of synchronous motion are identified, and their local exponential stability is studied using root locus methods

Communication using chaotic systems is considered from a control
point of view It is shown that parameter identification methods may be
effective in building reconstruction mechanisms, even when a
synchronizing system is not available. Three worked examples show the
potentials of the proposed method

In this paper we investigate the problem of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous transmitter dynamics and controlled receiver dynamics. The question is to find a (output) feedback controller that achieves matching between transmitter and controlled receiver. Several variants of the...

This paper gives necessary and suucient conditions for solvability of the strong input–output decoupling problem by static measurement feedback for nonlinear control systems. c 2000 Elsevier Science B.V. All rights reserved.

The synchronization problem for complex discrete-time systems is
revisited from a control perspective and it is argued that the problem
may be viewed as an observer problem. It is shown that for several
classes of systems a solution for the synchronization (observer) problem
exists. Also, by allowing past measurements a dynamic mechanism for
state...

Synchronization of complex/chaotic systems is reviewed from a dynamical control perspective. It is shown that the notion of an observer is essential in the problem of how to achieve synchronization between two systems on the basis of partial state measurements of one of the systems. An overview of recent results on the design of synchronizing syste...

this paper, we consider the design of observers for discrete-time nonlinear systems by means of so called (extended) observer forms. Loosely speaking, a system in observer form is a linear observable (continuous-time or discrete-time) system that is interconnected with an output-dependent nonlinearity. Observers for this kind of systems may be buil...

The synchronization problem for complex discrete--time systems is revisited from a control perspective and it is argued that the problem may be viewed as an observer problem. It is shown that for several classes of systems a solution for the synchronization (observer) problem exists. Also, by allowing past measurements a dynamic mechanism for state...

A method is described for the synchronization of nonlinear discrete time dynamics. The methodology consists of constructing observer-receiver dynamics that exploit at each time instant the drive signal and buffered past values of the drive signal. In this way, the method can be viewed as a dynamic reconstruction mechanism, in contrast to existing s...

The problem of setting route directives in a motorway network is formulated as a dynamic game problem. After restricting attention to the Nash equilibrium concept, a search procedure for such an equilibrium is proposed. 1 Introduction The purpose of this paper is to provide a short account of an investigation into routing control. The authors were...

A method, based on ideas from control theory, is described for the synchronization of discrete time transmitter /receiver dynamics. Conceptually, the methodology consists of constructing observer-receiver dynamics that exploit at each time instant the drive signal and past values of the drive signal. In this way, the method can be viewed as a dynam...

Secure communication using chaotic systems is considered from a control point of view. It is shown that a synchronization-based scheme for secure communication described in the literature may in fact be interpreted as an adaptive identification scheme. Two examples where the existing scheme fails to achieve the reconstruction of an encoded message...

Secure communication using chaotic systems is considered from a
control point of view. It is shown that a synchronization-based scheme
for secure communication described in the literature may in fact be
interpreted as an adaptive identification scheme. Two examples where the
existing scheme fails to achieve the reconstruction of an encoded
message...

This paper gives a characterization of the minimal order of a dynamic state feedback that solves the model matching problem for a given nonlinear SISO-system and a given linear SISO-model.

This paper gives a characterization of all transfer functions that may be realized via regular static-state feedback for a SISO nonlinear control system. It is shown that the question whether there exists a feedback realizable transfer function with a given number of zeros may be reduced to a well-known problem from real-algebraic geometry. As a by...

We investigate the problem of controlled synchronization as a
regulator problem. In controlled synchronization one is given autonomous
transmitter dynamics and controlled receiver dynamics. The question is
to find a (output) feedback controller that achieves matching between
transmitter and controlled receiver. Several variants of the problem
where...

A general setting is developed which describes controlled
invariance and conditioned invariance for nonlinear control systems and
which incorporates the previous approaches dealing with controlled or
conditioned invariant (co-)distributions. A special class of controlled
invariant subspaces, called controllability cospaces, is introduced.
These geo...

This paper gives necessary and sufficient conditions for solvability of the strong input-output decoupling problem by static measurement feedback for nonlinear control systems

A general setting is developed which describes controlled invariance for nonlinear control systems and which incorporates the previous approaches dealing with controlled invariant (co -) distributions. A special class of controlled invariant subspaces, called controllability cospaces, is introduced. These geometric notions are shown to be useful fo...

The problem of setting route directives in a motorway network is formulated as a dynamic game problem. After restricting attention to a Nash equilibrium, a search procedure for such an equilibrium is proposed. AMS Subject Classification (1991): 93C10, 93C95, 90D25. Keywords and Phrases: Motorway traffic, routing control, route directives, dynamic g...

A multiple finite source queueing model with a single server and dynamic, non-preemptive priority service discipline is studied in this paper. The times the customers spend at the corresponding sources are exponentially distributed. The service times of the customers can follow exponential, Erlang or hyperexponential probability density function. B...

The relation between the solvability of the disturbance decoupling
problem for a nonlinear system and its linearization around a working
point is investigated. It turns out that generically the solvability of
the disturbance decoupling via regular dynamic state feedback is
preserved under linearization. This result gives a partial
interpretation of...

We consider the problem of nonintera.cting control with stability for a square affine nonlinear system, where its decoupling matrix is not necessarily invertible. The recent notion of quasi-static state feedba.ck is used. The results of this paper show that the dimension of the fixed. dynamics with respect to any quasi-static state feedback ma.y be...

A generalized setting is developed, which describes controlled invariance for nonlinear control systems and which incorporates the previous approaches in dealing with controlled invariant distributions. This generalized notion of controlled invariance is of major importance for the geometric description of dynamic feedback problems.

We study the strong dynamic input-output decoupling problem (SDIODP) for nonlinear systems. It is shown that, given a generically satisfied assumption, the solvability of the SDIODP around an equilibrium point is equivalent to the solvability of the same problem for the linearization of the system around this equilibrium point. We introduce the Sin...

In this note we study the strong dynamic input-output decoupling problem for nonlinear systems. Using an algebraic theory for nonlinear control systems, we obtain for a dynamic input-output decouplable nonlinear system a compensator of minimal dimension that solves the decoupling problem.

We study the strong dynamic input-output decoupling problem (SDIODP) for nonlinear systems. It is shown that, given a generically satisfied assumption, the solvability of the SDIODP around an equilibrium point is equivalent to the solvability of the same problem for the linearization of the system around this equilibrium point. We introduce the Sin...

The nonregular dynamic disturbance decoupling problem for nonlinear control systems is introduced. A local solution is given by means of a constructive algorithm that is based on Singh's algorithm and the clamped dynamics algorithm. Further studied is the nonlinear model matching problem that is defined as follows: given a nonlinear control system,...

In analogy with the dynamic input-output decoupling problem the dynamic disturbance decoupling problem for nonlinear systems is introduced. A local solution of this problem is obtained in the case that the system under consideration is invertible. The solution is given in algebraic as well as in geometric terms. The theory is illustrated by means o...

This note provides a sufficient condition for steady states arising from economic optimal control models to be locally asymptotically stable. In particular, we show that if some submatrix of the matrix of eigenvectors of the corresponding Jacobian is invertible, the stable manifolds is locally y-parametrizable.

The paper deals with the disturbance decoupling problem in discrete nonlinear systems with many inputs and outputs. The compensator is constructed in the form of dynamic feedback relative to state. Such compensator ensures invariance of system output with respect to disturbances. Necessary and sufficient conditions of the solution existence are pre...

We extend earlier results on the Dynamic Disturbance Decoupling Problem via regular feedback to nonsquare, noninvertible systems. Instrumental in the solution of the problem is the so called Singh’s algorithm and what we like to call a Singh compensator. The theory developed is illustrated by means of two examples. Moreover, we make some remarks ab...

Some recent advances in the solution of the nonlinear Model Matching Problem are pursued further. First we study the Model Matching Problem making use of the notion of clamped dynamics or zero dynamics and a version of the modified Hirschorn algorithm. Then, making some extra assumptions, we generalize recent results on the nonlinear Model Matching...

The model matching problem consists of designing a compensator for a given system, called the plant, in such a way that the resulting input-output behaviour matches that of a prespecified model. In this paper a local solution of the nonlinear model matching problem is given for the case that the model is decouplable by static state feedback. The ma...

The model matching problem consists of designing a compensator for a given system, called the plant, in such a way that the resulting input-output behavior matches that of a prespecified model. In a recent paper it was shown that in case the model is decouplable by static state feedback and generic conditions on the plant are satisfied, the model m...

The input-output decoupling problem with stability for Hamiltonian systems is treated using decoupling feedbacks, all of which
make the system maximally unobservable. Using the fact that the dynamics of the maximal unobservable subsystem are again Hamiltonian,
an easily checked condition for input-output decoupling with (critical) stability is dedu...

We solve the Hamiltonian model matching problem by formulating it as a Ilamiltonian disturbance decoupling problem with observation feedback and disturbance measurements. It turns out that the conditions for solvability of the Hamiltonian model matching problem are the same as those for solvability of the ”normal” model matching problem. A procedur...

Some recent advances in the solution of the nonlinear Model Matching Problem are pursued further. First we study the Model Matching Problem making use of the notion of clamped dynamics or zero dynamics and a version of the modified Hirschorn algorithm. Then, making some extra assumptions, we generalize recent results on the nonlinear Model Matching...

We investigate the connections between the solvability of the dynamic disturbance decoupling problem with exponential stability (DDDPes) for a nonlinear system and the solvability of the same problem for its linearization around an equilibrium point. It is shown that under generic conditions the nonlinear DDDPes is solvable for a nonlinear system i...