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Please follow the links to view the publication.Pupillary light reflex system order reduction by RMS model order reduction MATLAB Tool
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0456
A new method for the reduction of high-order, linear time invariant systems is proposed. The method is based on the differentiation technique and generates low order stable models retaining both the initial Markov parameters and time-moments, of the original system. Theses biased models give a better approximation for both the steady-state as well as the transient part of the time response. The proposed procedure avoids the necessity of formulating Routh-type arrays, application of reciprocal transformation, finding the time moments of the nth order original system before hand and the use of gain-factor, to generate the denominator and numerator of the models unlike other methods. The new procedure is simple, direct and computationally superior to other methods based on the differentiation technique. The method is well illustrated with pupillary light reflex system. This method is implemented using RMS Model Order Reduction MATLAB Tool and also responses are analysed. In this paper a MATLAB-based tool with a Graphical User Interface (GUI), to compute reduced models of a low damping plants are presented. The model reduction techniques implemented in this tool are based on Different techniques. The method selected in this paper is Hybrid method. Upon execution of the toolbox, a GUI will appear with four frames named "METHODS", "INPUT DATA", "OUTPUTOPTIONS", and "DISPLAYUNIT".A preliminary study into the application of mathematical wireless classroom system based on the handheld graphing calculating device
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1478
Mathematical wireless classroom system is an interactive teaching system using handheld graphing calculating devices as a carrier, which combines the advantages of graphing calculating technology with wireless technology. It provides a technical solution for teaching difficulties in one-to-one graphing calculating learning circumstances, such as learning monitoring, interactive teaching, immediate learning evaluation. Herein, this paper preliminarily discussed the superiority of this new technology, and its influence on students' devotion level, learning mentality, classroom interaction and reflective learning after its application into mathematics teaching. The investigating data demonstrated the clearly positive effect, as well as some problems. And we analyzed the potential reasons by teacher interview and student interview to provide a valuable reference for the technological development and application of mathematical wireless classroom system.Realization of grid fault on grid connected wind energy conversion system using real time simulator
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0351
DFIG is the most common rotatory machine which is used on the grid connected wind energy conversion system for the fulfilment of the system requirement such as grid stability, fault ride through (FRT), power quality improvement, and grid synchronization and power control etc. Though the requirements are not fulfilled directly by the machine rather the control strategy is used in both the stator as well as rotor side along with converters to fulfil the requirements stated above. In this paper the performance of the DFIG system is analysed under the symmetrical grid fault and the theoretical results are obtained from the MATLAB/SIMULINK environment and the proposed work is validated experimentally using RT-LAB.Processing of audio signal in all fiber-optic sensor system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.1159
This paper discusses the disposal of audio signal of all fiber optic vibration sensor. Disvantages what electricity and light being combined together in traditional audio transmission cannot be divided has been overcome. The system also diminishes the interference from noise, electromagnetism, and so on. It also processes the advantage that can transfer audio signal in a long distance. Audio signal of this new fiber sensor also has been studied in the paper. Audio signal has been extracted and stored by using labview, and stored by using labview, and the noise reduction filter of audio signal has come true by matlab. At the end of the experiment, the result tells us that signal has been well extracted and stored through the disposal of matlab, audio noise has been decreased a lot.An efficient parallel SAI preconditioner for multilevel fast multipole algorithm for scattering by extremely large complex targets
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1355
A highly efficient parallel SAI preconditioner is presented. This preconditioner is incorporated into our previously well developed parallel MLFMA code, and successfully computes scattering by a sphere with a diameter of 750 wavelengths, involving over 315 millions unknowns. The capability of this parallel SAI preconditioner is further demonstrated on computing scattering by an extremely large tank with a size of over 300-wavelengths containing around 35 millions unknowns, where convergence cannot be achieved without this SAI preconditioner.Parallel mechanism character arrays of topology graphs isomorphism identification and creation automatically
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1522
How to depict topology graphs and how to identify isomorphic topology graph is the key in parallel mechanisms type synthesis by using topology graphs. In method of systematic linkage and topology matrix-graph approach for parallel mechanism type synthesis, the character of topology graphs are depicted by character arrays. So the isomorphism identification of topology graphs equate with that of character arrays. Based on this analyse deep the inherent rules of character arrays and then define isomorphic character arrays in virtue of the concept of character string. Then put forward the new approach to identify isomorphism of character arrays by virtue of identification matrix. Study how to find all character arrays that are exhaustive and non-isomorphic. Accordingly creating automatically of character arrays can bring into effect. Moreover program about these process with Visual Basic. (5 pages)FH/MPS hybrid radar waveform
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0278
A novel waveform design is proposed in order to fulfil several requirements and avoid many disadvantages encountered in some of known waveforms. The proposed waveform is a hybrid complex form that is named as the frequency-hopped/minimum peak-to-sidelobe (FH/MPS) waveform. Many computer simulations using MATLAB were made so as to investigate the FH/MPS radar waveform. Very significant results are obtained, regarding ambiguity in range and velocity measurements and improvement of the signal-to-noise ratio for a different number of codes. (4 pages)Thermal response of a three core belted PILC cable under varying load conditions
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0621
The most important indicator of the health of electrical plant items is the condition of their insulation. In the case of underground cables an important issue is the operating temperature and indeed the thermal history of the cable. There are several factors which will determine the thermal behaviour of a given cable installation. These include the assumed ampacity, the cable construction and circumstances of installation, the thermal properties of the surrounding soil and the ambient temperature. The work presented in this paper involves the use of COMSOL multiphysics finite element software to develop an integrated electrical, thermal and mechanical model of buried single or multiphase cables that simulates the behaviour occasioned by a varying load. The principal heat source in the problem is the Joule heat dissipated in the conductor(s). The transfer of this heat to the surroundings is governed by the geometry and material properties of the conductor, insulation, screening, sheathing and trench fill material as well as the ambient conditions. The thermal and electrical systems are coupled via the temperature dependence of the resistivities of the conductor and sheath materials. The input data to the model is provided in the form of time series describing the variations in load over a 24-hour cycle and the output takes the form of the thermal response of the cable for given installation and ambient conditions. (4 pages)Dynamic response of distributed synchronous generators on faults in HV and MV networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0701
Connection of distributed generators (DG) on existing power distribution networks requires solution of technical, economical and regulatory issues. A brief description of current status of DG in Bosnia and Herzegovina, with special attention to the technical impact of integration of small hydro power plants with synchronous generators, is given in this paper. Dynamic response ofDG (namely small hydro power plants with synchronous generators) on disturbances in HV and MV networks is analyzed in detail. Simulations ofDG dynamic response are performed using free, open-source MATLAB/PSAT software package on a simple test model of distribution network with DG. Several scenarios are studied. Finally, areas for further research are identified and presented. (4 pages)Research and practice on experiment-teaching mode of probability and statistics based on SPSS under network environment
http://dl-live.theiet.org/content/conferences/10.1049/ic_20080253
To reform traditional teaching mode, inspire students' learning interest and enhance teaching quality and effect of probability and statistics, using network technology and statistical software, three aspects of probability and statistics teaching are researched mainly. Firstly, a new reform thinking which links teaching organizers with such teaching factors as teaching object and teaching environment by network experiment-teaching mode based on SPSS is presented to change present pure-theory teaching mode. Secondly, a digital experimental teaching mode is established, in which teacher and student can be highly interactive with each other. At last, an experimental teaching system of probability and statistics supporting the mode is developed.Programmable hardware systems using model-based design
http://dl-live.theiet.org/content/conferences/10.1049/ic_20080618
Embedded systems are becoming ever more complex, and the costs of errors incurred during traditional development lifecycles are increasingly unacceptable. This lecture introduces model based design as a method for reducing the likelihood of such errors, and explains how products from The MathWorks such as Simulink and the Simulink HDL Coder can be used to achieve this in the context of programmable hardware. The lecture will be illustrated with a simple example from image processing, illustrating the use of reference models, model elaboration, conversion for fixed-point implementation, HDL generation and verification through co-simulation. (13 pages)Ordering of fuzzy quantities and its software
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080794
Firstly, this paper summarizes researches on the ranking of fuzzy quantities, which includes the description of ordering problems, application fields, review and classification of ordering indices, rationality of an ordering approach. Then, based on our research, we develop a software package. This paper gives a detail interpretation of the functions, performance and usage of the package.Whither computational electromagnetics? A practitioner's look at the crystal ball
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080252
The paper gives a brief review of the existing CEM solvers in the context of parallel processing, which is the way forward to the future. Next, it would go on to describe three parallel algorithms, based on MOM, FEM, and FDTD, respectively, that may play major roles in the development of parallel CEM solvers.The creation of a new educational software for designing wire winding of electrical machines using MATLAB
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080514
The creation of more than 10,000 optimal programming command lines, in addition to the various wire winding techniques of electrical machines, has created the new interactive powerful tool for solving the theoretical problems of wire winding. This educational software, uses special methods to develop itself, and designs an idea which has not formed so far. For this reason it creates a flexible communication graphic design according to different interests of users. Also, it has the capability to be involved in MATLAB as one the features of the electrical machines.Model based design for power systems protection relays, using MATLAB & Simulink
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080116
In the world of power system relays, there have been significant changes in the technology used to implement the protection; electro-mechanical relays, static relays, digital relays and numerical relays have all been developed to provide the required protection and control. However, the development process for these has by and large remained a manual, document led process. This inevitably leads to delays, interpretation errors and omissions which are often not identified until late in the process - when it is time consuming and expensive to change the design. Furthermore, the design has to be verified and validated from requirements through to the final implementation. Manual processes make this a laborious and thankless task. By utilising the powerful and flexible model based design process allowed by MATLAB® & Simulink®, this paper will show how complex and innovative new working methods can be developed to improve the design cycle. These will allow rapid modeling and testing of algorithms, before committing to the expense of development for the final hardware platform, and the resulting cost benefits achieved by avoiding late changes to the design. Meanwhile, consistent behaviour can be confirmed and demonstrated at all stages.Power differential protection as primary protection of transmission lines and busbars
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080015
Active power differential protection has recently been proposed as a novel technique to increase the protection reliability of transmission lines and busbars. In comparison with current differential protection, it is more reliable, faster, needs less input parameters and communication devices; those make it suitable to be used as a protection scheme of the wide area backup protection. On the other hand, active power differential protection cannot recognise the faulted phase of the protected object and therefore cannot operate for single pole tripping. In this paper, a new technique has been proposed to resolve the single pole tripping limitation of the active power differential protection. In this technique, when APDP relay produces trip command, an external logic compares per phase differences of the active power flowing at the line ends. For faulted phase, the difference is more than the others. The proposed technique has been evaluated using a MATLAB simulator configured to model effects of different faults on a typical 400 kV transmission line. The method has also been tested on simulated Northern Ireland Electricity (NIE's) 275 kV network to show the effectiveness of the proposed technique for a real system data. Results indicate that the new logic is reliable to be used as single pole tripping detector for APDP algorithm.An algorithm for electronic circuit solution using MATLAB
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070694
In this paper an algorithm for electronic circuit solution using MATLAB is proposed. The given electronic circuit consisting active elements observes the nonlinearity. So first the circuit equations are linearised by converting the active elements e.g transistors into diodes and other resistive elements by Eber's-moll model (Millman and Halkias). The resulting linear simultaneous equations are solved for computing the values for various voltages using MATLAB. These features make the proposed algorithm as the basis for AC analysis of very large electronic circuits.Parallel implementation of ADI-FDTD on shared and distributed memory computers
http://dl-live.theiet.org/content/conferences/10.1049/ic.2007.1206
We present results of a parallel ADI-FDTD implementation on shared and distributed memory computers using the Message Passing Interface (MPI) library. The ADI-FDTD method involves solving in every time step a tridiagonal matrix system of equations over the xy, xz, yz planes of the domain to update the electric field components. In our parallel implementation, the three-dimensional computational domain was spatially decomposed in two directions. Each tridiagonal matrix system is solved by a single processor, with the parallel computer architecture being exploited to solve multiple systems at the same time. This avoids inefficiency associated with using parallelised tridiagonal solver on a small matrices. The amount of data exchanged between processes was proportional to the volume of the local sub- domain. The code was developed in C programming language using the Message Passing Interface (MPI) library and tested on two high performance computers (IBM p690 symmetric multi-processor and a general purpose distributed memory cluster). Benchmarking simulations ran faster as the number of processors was increased, with a maximum speedup factor of 11 for the shared memory system and 4 for the distributed memory system. For the particular simulations that we ran, the speedup factor did not significantly improve with the use of more than 10 processors for the shared memory system and 7 processors for the distributed memory system. (6 pages)Realization of close coupling plane double inverted pendulum based on digital motion technology
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061098
Inverted pendulum system is a typical close coupling, nonlinear system with high-rank, multi-variable and serious instability. Aiming at the control problem of Inverted pendulum, the conventional operators have PID operator, pole disposition operator and optimal control operator and so on, most of which are aimed at the single linear or single plane inverted pendulum. Taking into account the control law of the car's displacement, speed, angle, angular-rate and angular acceleration of rod 1 and rod 2 under the input electric voltage, these traditional operators such as LQR (linear quadratic regulator) have an effect of better stability, but sacrifice the robust and transient performance. In view of uncertain factors in pendulum systems, authors design an intelligent controller, i.e. the robust LQR controller for plane two rods inverted pendulum based on the robust optimal control with self-adaptive performance in order to improve the transient state and robustness of the system, then simulate the pendulum system by Matlab. Thus we can get the contrasted response curves of the angle of two rods and car situation according to the two designed methods to compare their advantages and disadvantages. Finally BC 3.1 is adopted to write the digital motion control program and realize the real time control and material object control of the plane two rods inverted pendulum.Applying BP neural network to forecast the mid- and long-term power load
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061670
Electric power load forecasting is a very important work, which has vital significance on guaranteeing the healthy development of electric power industry and national economy. This paper analysed the relevant influencing factors on mid-and long-term electric power load, establishes the forecasting model of electric power load by BP neural network . It improved the problem that the training speed of BP neural network is slow in some conditions. At last, the model is validated with concrete examples with programs compiled with Matlab toolbox, and very good results are obtained. (5 pages)A Matlab/SIMULINK toolbox for the simulation-based high-level synthesis of Nyquist-rate data converters-application to a pure digital 0.13 μm CMOS 12-bit@80 MS/s analog front-end for PLC/VDSL
http://dl-live.theiet.org/content/conferences/10.1049/cp_20050144
This paper presents a toolbox for the time-domain simulation and optimization-based high-level synthesis of Nyquist-rate data converters in Matlab<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">®</sup>. Behavioural models of building blocks, including their critical non-idealities, are incorporated into SIMULINK<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">®</sup> as C-compiled S-functions. This approach significantly speeds up system-level simulations while keeping high accuracy and interoperability of different subcircuit models. Moreover, their combined use with an efficient optimizer makes the proposed toolbox a valuable alternative for the design of broadband communication analog front-ends. As a case study, an embedded 0.13 μm CMOS 12 bit@80 MS/s A/D/A interface for PLC and VDSL is synthesized to show the capabilities of the presented tool.Frequency response analysis in diagnosing transformer winding movements
http://dl-live.theiet.org/content/conferences/10.1049/cp_20050062
Diagnosis of transformer winding movements through frequency response analysis, (FRA) relies on correct interpretation of the complex FRA results. Direct and manual comparison between two FRA test results is the current approach used by maintenance engineers and each FRA signature usually contains about 2000 data points. An automatic approach to represent the FRA signature using a transfer function with parameters of the gain, the zeroes and the poles is studied in this paper. The transfer function estimation code is developed in MATLAB and sensitivity study is carried out on the effect of the parameters of the estimated transfer functions.MATLAB/Simulink model as tool for process design commissioning
http://dl-live.theiet.org/content/conferences/10.1049/ic_20040635
The paper discusses the MATLAB/Simulink model as tool for process design commissioning. The design is to improve the plant and control system. The benefits of commissioning are to pre-empt commissioning in becoming a part of a design or redesign cycle. Also to reduce or eliminate time spent on controller tuning and provide initial tuning settings and constraints. (10 pages)Simulink-based modular modeling of power systems for fault-detection studies
http://dl-live.theiet.org/content/conferences/10.1049/cp_20030596
In this paper we present a new approach to the nonlinear modeling of power systems. The approach utilizes the powerful graphical features of the combined Simulink and Matlab software packages. The power system comprises a number of units each of which is decomposed into self-contained modules interconnected with each other via a well-defined set of inputs and outputs. The decomposition is performed in such a way as to allow the easy application, detection and clearance of faults. A unit typically comprises a synchronous machine model, exciter model and a voltage regulator model. All units of the power system are then interconnected through a network of buses, lines and loads. An example of a single-machine infinite bus is presented and fault conditions are simulated and results are shown.An integrated environment for simulation and modelling
http://dl-live.theiet.org/content/conferences/10.1049/ic_20000227
It is now widely accepted in the automotive electronics industry that the scale and complexity of the software content in cars is destined for dramatic increase in the coming five years, fuelled by intense competitive pressures. Kennedy Carter, along with its partners in two EU-funded research programs, has accepted the challenge of creating the definitive integrated development environment for embedded automotive software for the first decade of this century (2000-2010). The vision that informs these two projects is the need for an integrated development environment conforming to an open systems/software architecture. Part of that vision is that the algorithmic, control theoretic emphasis of much software development in the automotive industry hitherto will not be sufficient to manage the scale and complexity of the software challenge that the industry faces. Thus, tools such as MATRIXx and MatLab must be augmented by tools which have been proven in large scale telecommunications and aerospace projects and which support the separation of concerns, rapid prototyping, co-design and code generation. Kennedy Carter is now able to offer an integrated development environment (IDE), comprising the I-UML, I-SIM/RT and I-CCG products. Used in conjunction with MATRIXx from Integrated Systems, or MatLab/Simulink from The Mathworks, these products are able to realise the vision. The result is a development environment that offers comprehensive and flexible support for automotive system development. (4 pages)Application of modern simulation tools to power plant modelling and analysis: two industrial case studies
http://dl-live.theiet.org/content/conferences/10.1049/ic_20000229
There are now a range of advanced simulation tools available which facilitate the modelling and analysis of complex systems. At the ABB ALSTOM POWER Technology Centre, the Control Group have been utilising the versatility of two such products to model and simulate complex industrial power plants. The potential benefits include improvements in the plant design, control system design and in process operation. The paper describes two industrial case studies where the specialised power plant simulation tool ACSL/MMS has been used in conjunction with MATLAB/SIMULINK to model, analyse and undertake control design studies on power plants. (22 pages)Comparison of regional variability in multi-site photoplethysmographic pulse wave characteristics
http://dl-live.theiet.org/content/conferences/10.1049/cp_20000313
The characteristics of the photoplethysmography (PPG) pulse signal depend upon where they are made; with pulses from the various peripheral sites showing differences in amplitude and transit time, and variation of each over time. By studying the pulses obtained simultaneously from 6 peripheral sites (right and left ears, thumbs, and toes), the bilateral and segmental characteristics should allow important information about the peripheral circulation to be extracted. A multisite photoplethysmography pulse measurement and analysis system is described which includes a MATLAB-based suite of signal processing algorithms for analysis of the waveforms on a beat-to-beat basis. Multi-site pulse waveforms were collected from 20 normal subjects whilst they performed a slow paced breathing exercise at 1 breath every 10 s for 300 s. In this study the PPG pulse waveform characteristics at the 3 segmental levels (right and left ears, thumbs, and toes) were assessed using two types of analysis: (i) pulse amplitude and its variability, and (ii) pulse transit time and its variability. The mean calibrated pulse amplitudes were (in arbitrary units); ears (0.023), thumbs (0.043), and toes (0.013), with coefficients of variability; ears and thumbs 14%, and toes 20%. A significant difference in pulse transit time of 4 ms between the right and left toes was detected. The mean overall pulse transit times were; ears (0.133 s), thumbs (0.199 s), and toes (0.302 s), with coefficients of variability; ears 2.6%, thumbs 1.9%, and toes 2.1%. In the study we utilized signal processing algorithms to calculate on a beat-to-beat basis measures of pulsatility and determine a set of normative data for our multi-site pulse system.Opening remarks from the Chairman: a note on the development of computer algebra and its emerging role in control engineering
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990480
The author discusses the history of the development of computer algebra. He highlights a selection of textbooks addressing many theoretical, practical and applicative elements of the field over the years. He considers the role of computer algebra in control engineering. (6 pages)Symbolic algebra toolbox for the design of dynamical adaptive backstepping controllers
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990484
A symbolic algebra toolbox is described for the design of dynamical adaptive nonlinear controllers for regulation and tracking tasks of a class of observable minimum phase uncertain nonlinear systems. This toolbox also allows the design of non-adaptive controllers for systems without uncertainty, and adaptive sliding mode controllers (SMC) to provide robustness in the presence of disturbances. The design procedure employs the basic ideas of the adaptive backstepping algorithm with tuning functions via input-output linearization, and is applicable to both triangular and nontriangular systems. (13 pages)Structural identifiability of controlled state space systems: a quasiautomated methodology for generating identifiable reparameterisations of unidentifiable systems
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990487
In this paper two of the most commonly used approaches to the structural identifiability analysis of controlled nonlinear parameterised systems are described. The application of these techniques within symbolic manipulation packages is also illustrated. Whilst this analysis has been performed using Mathematica it could equally well have been carried out within most other currently available symbolic software packages. A problem that arises in structural identifiability analysis is what to do with unidentifiable systems. A procedure for generating locally identifiable reparameterisations of unidentifiable nonlinear systems is also presented in this paper. This procedure can be almost completely performed within an appropriate symbolic manipulation package as illustrated by the example presented. (12 pages)The systematic design of PID controllers
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990489
A brief overview of the design of PID controllers, in terms of established procedures and recent methods of determining the limiting values of the parameters of the PID controller to guarantee closed-loop stability and performance is given. However, a new and computationally faster way of designing (tuning) PID controllers, and other 2 or 3-parameter compensators, based on the Nyquist plot, that guarantees both robust stability and performance is presented and illustrated. (9 pages)Using Maple for the transformation of fuzzy systems into their mathematical representation
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990485
In this paper, the use of Maple for investigations of the mathematical description of fuzzy systems is presented. This work is divided into four parts. First, a short outline of a Maple tool is introduced that has been implemented to generate the mathematical function representing a certain class of fuzzy system analytically. The results derived with the help of this tool are given in the second part. Here, the structure of the function and the influence of the parameters of the fuzzy sets are revealed. Based on these results, the third part is concerned with a method to implement a linear control system with the aid of fuzzy logic. In the forth part, the Windows software program Fuzzy2MATH is presented, which has been implemented to provide the user with a convenient application of the results obtained by Maple. (13 pages)Symbolic packages for dynamic sliding mode output feedback control of nonlinear systems
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990482
The combination of symbolic computation and numerical calculation will undoubtedly increase the power of control systems design. Although several control design toolboxes exist, many based on the simulation software MATLAB, they are primarily geared for matrix operations. General nonlinear controller design certainly needs the combination of both symbolic and numerical computations. People may argue that one can use the MATLAB symbolic toolbox which is essentially a small subset of Maple-V. However, this symbolic toolbox can only be used to solve small scale nonlinear control design problems. It is not suitable for general nonlinear computer aided control systems design without further C code for interface, as one cannot dynamically allocate memory for an indexed function of time t of arbitrary dimension, for example. This interface will use no less effort than using Mathlink as an interface between Mathematica and MATLAB. Dynamic sliding mode control using state feedback for minimum phase MIMO systems and for MIMO uncertain systems has been developed. These methods have been implemented with Mathematica and MATLAB using Mathlink as an interface. These packages have been used for nonlinear control design. (8 pages)Application of symbolic manipulation to the analysis of dynamic characteristics of a flexible robot manipulator
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990486
This paper presents an investigation into the analysis of dynamic behaviour of a flexible robot manipulator using a symbolic manipulation approach. A constrained planar single-link flexible manipulator is considered. The finite element method is used for dynamic modelling of the system. A symbolic algorithm is developed using Macsyma. A general solution describing the dynamic behaviour of the manipulator is obtained. The effect of physical parameters of the manipulator on the characteristics of the system and the impact of their variation on the minimum-phase features of the system are studied and assessed. (5 pages)Use of symbolic computation to gain insight into a difficult eigenvalue problem
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990483
The solution of a nonlinear dynamic optimal control problem often requires an algorithm which updates a trial solution from iteration to iteration. In such algorithms, it is important to ensure stability so that the iterations are stable and converge in a satisfactory manner. Particular emphasis is given to an algorithm, known as dynamic integrated system optimisation and parameter estimation, DISOPE, (P.D. Roberts, 1993), for the solution of continuous nonlinear optimal control problems subject to model-reality differences. The DISOPE technique is described as applied to the nonlinear optimal control situation. Then, for the purpose of local convergence and stability analysis, the linear situation is considered, where it is shown that the method can be represented as a unit memory linear repetitive process. A stability theorem is then stated, providing a sufficient and necessary condition for asymptotic stability if the solutions of a given equation all lie within a unit circle in the complex plane. The computational solution of this equation is then considered. Finally, taking a simple scalar case, symbolic computation is employed to achieve insight into the nature of the solutions of the stability equation. (9 pages)Computation of the least common multiple of a set of polynomials: symbolic and numerical approaches
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990490
The problem of computing the least common multiple (LCM) of a set of polynomials is an integral part of algebraic synthesis methods in control theory. We investigate a number of alternative algebraic methodologies for computation of LCM, which can be performed symbolically, but can also lead to numerical algorithms for evaluation of exact, as well as approximate LCMs. The latter problem (approximate LCMs) is important especially when the problem data are not exact and thus the use of symbolic means does not seem to be appropriate. A new algebraic procedure with its symbolic and numerical implementations are presented, which make extensive use of new robust algorithms for computation of the greatest common divisor (GCD) of a set of polynomials. (10 pages)A symbolic investigation of pole-zero cancellation for a double inverted pendulum using torque inputs
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990488
Modern computational packages are able to perform highly complex manipulations of symbolic variables, thus offering insights into a variety of mathematical problems. The symbolic manipulation packages REDUCE and MATLAB Symbolic Toolbox are used in an investigation into controllability with respect to torque inputs of a double inverted pendulum. (10 pages)Limit cycles in control systems with multiple nonlinearities and parameter uncertainties
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990481
The describing function method can be used to analyze control systems with separable nonlinearities. In the paper, together with some well established robustness tools for linear systems, the method is used in the prediction of limit cycles in uncertain systems with multiple nonlinearities connected in series. Uncertainty is assumed to exist in terms of parameter variations in both the linear and the nonlinear elements. The software tools developed for this purpose are discussed and utilized to provide illustrative examples. The results are, of course, subject to the usual errors and restrictions of the describing function method. (9 pages)Exploring competition and co-operation for solving the euclidean travelling salesman problem by using self-organizing map
http://dl-live.theiet.org/content/conferences/10.1049/cp_19991105
In the last few years, several new results on self-organizing map algorithms applied to the Euclidean travelling salesman problem (ETSP) have emerged. All of them have attempted to find quasi-optimal solutions for this NP-complete combinatorial problem based on the functional role of the learning process mapping which is understood to occur in the brain. This paper brings an innovative computational investigation based on a new model of lateral interactions between neurons that can be thought of as introducing co-operation between them. Such interactions are now being observed in biological neural nets. Its application to ETSP obtained results never before achieved. Simulations using a sequential machine for well-known and difficult TSP library instances as well as for problems with over two thousands cities are discussed in this paper.Benefits of general purpose mathematical software in modelling electronic systems
http://dl-live.theiet.org/content/conferences/10.1049/ic_19980586
It is often possible to model the behaviour of devices or systems using analytical techniques, but the complexity of such models may make such calculations impracticable without computer support. In the past, the only solution to this problem was to write specialised code to implement the required calculations. The subsequent appearance of spreadsheets provided a mechanism for avoiding this requirement in some limited applications, but these tools are not well suited to working with complex numbers, vectors or complicated equations. In recent years, however, a wide range of general purpose tools have become available which permit the user to carry out extensive mathematical analysis without recourse to writing code. The capabilities of these tools range from rapid prototyping of numerical methods (e.g. finite element solvers or signal processing algorithms) through to purely symbolic manipulation of equations. Between these two extremes, however, there is frequently an important role for the evaluation of complex analytical expressions over a range of parameter values. The study of a preliminary model is also frequently found to be beneficial in gaining a better understanding of more complicated systems, which may ultimately require more sophisticated numerical modelling. However, this type of analytical study is often sufficient in itself to guide the design or understanding of some systems, and some representative examples of this are outlined below. (6 pages)Some applications of MATHCAD and MATLAB in microwave component synthesis
http://dl-live.theiet.org/content/conferences/10.1049/ic_19980590
This paper describes a range of different applications of MATHCAD and MATLAB in microwave component synthesis. The examples are drawn from both research and teaching in microwave engineering. (6 pages)Using Mathematica<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">®</sup> to explore the behaviour of phase-locked loops
http://dl-live.theiet.org/content/conferences/10.1049/ic_19980588
The motivation for this project was to gain a better understanding of the nonlinear behaviour of a phase-locked loop (PLL) circuit. The existence of chaos in an ordinary PLL circuit being used for frequency demodulation was demonstrated by Endo et al. (1988), and in this paper some of the previous results and recent developments are demonstrated using Mathematica. We have found that investigation of the nonlinear behaviour of the PLL has benefited from inputs from more than one discipline. In this context, an advantage of Mathematica is that it provides a convenient framework in which the results from various disciplines can be exchanged. The physics-based analytical tools can be computed symbolically, the electronics-based behavioural models of circuits can be solved numerically, and the geometric techniques of nonlinear dynamics can be implemented straightforwardly. (6 pages)Exact algebraic pole-zero cancellation using symbolic mathematical computation
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980212
Modern symbolic computational systems which perform automated manipulation of mathematical variables offer insights during modelling and problem solving which remain otherwise partially or wholly obscured to the analyst. The classic inverted pendulum model is re-visited, and previous work concerning the systems controllability is investigated. In particular, the ability of the software to factorise complicated multivariable polynomials is exploited to identify, in fully general form, the anticipated pole-zero term cancelling throughout the transfer functions of the system when it is in a state of un-controllability. All three balancing problems associated with the two link pendulum are treated, and the phenomenon of non-controllability is examined in this way along the entire `curve of non-controllability' which, within the approximation of linearity, theoretically exists for each when damping is present.Linear model identification toolbox for dynamic systems
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980310
A new methodology for model structure identification is presented. This is implemented as a new toolbox of MATLAB. The methodology developed has two parts, the first one has the objective to find a pure delay using the estimated impulse response, and the second one, uses at same time the minimal value of the identification criteria and the representative value of numerator coefficients. The graphical interface and the results obtained using some real applications are also presented.MATLAB-SIMULINK<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">®</sup> library for AC drives simulation
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980637
The development of the control structures for AC motors (vector control, fuzzy control, etc.) is easier if good models are available, in order to verify the different ideas. There are necessary accurate models for the AC motors (induction and synchronous), for the different types of inverters and for the blocks often used in the control loops. By using the MATLAB-SIMULINK(R) facilities, a library containing models for the mentioned subsystems was developed. It consists of three divisions, each of them corresponding to one of the described sub-systems: power sources, motors, control. An important aspect is that the control blocks were also used for real time control of the drives, by using the friendly interface supplied by dSPACE GmbH with its DSP control board DS1102. The paper describes the structures and the facilities of the built blocks, as well as examples of models of the complete systems. The simulation results are compared with the experimental ones. The correctness of the developed models is fully confirmed, thus a strong tool for the study of the AC drives is made available.A frequency domain toolbox using interval arithmetic
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980376
In linear control theory the frequency domain approach and the state-space approach are equivalent. But for the implementation of numerical algorithms the use of state-space equations is preferred. To avoid the numerical problems caused by a polynomial arithmetic, the use of an interval arithmetic with variable length of the mantissa is suggested. Some basic algorithms for polynomial and transfer-function matrices implemented in interval arithmetic are stated. A control example shows the feasibility of this method.A model order reduction technique for parametric uncertain models
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980245
Applying model-order reduction algorithms developed for fixed-parameter models based-on balancing transformations to parametric uncertain models is considered. High-order models are first decomposed into sub-models of lower order using serial and parallel decompositions, then model-order reduction algorithms implemented in a symbolic environment are used to reduce these sub-models. At the end of this process, a reduced-order model of the original higher-order model is produced by recombining the reduced sub-models.The use of symbolic algebra in robust control
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980422
In the analysis of systems with parametric uncertainty, complex symbolic computations are often encountered. Therefore, computer implementations require the use of symbolic environments. Such an implementation is provided in the Parametric Systems Toolbox, a collection of files written in the MATLAB environment for the analysis and design of such systems. The importance of symbolic computation in this type of system analysis is discussed, and illustrative examples are given.Mathematics for engineers in the Computer Age
http://dl-live.theiet.org/content/conferences/10.1049/ic_19970456
In the last two decades or so the single most important issue in the debate on the teaching of mathematics to engineers has been the role of the computer. The rate of technological development is accelerating away at an increasing rate from our capacity to adjust to the changes. Time is needed to think through the strategies which might be employed in order to harness the benefits that these developments might bring; thus far that time has not been granted. While simple operations in arithmetic, algebra and calculus can (and should) still be carried out by `pencil and paper' it is surely reasonable that calculators and computers be used to handle the more tedious, lengthy and complicated operations. The rapid processing of data by computers has ensured that the time-scale required to perform the calculations which make a modelling exercise meaningful and worthwhile is now at a realistic level. This is an area which has, so far, not been developed to the extent that it merits. Mathematics for engineers in the 21st Century should have a syllabus which reflects the technological developments in computers in terms of both syllabus content and style of teaching. It is important of course to retain mathematical integrity, but it is no use defending the indefensible. What can sensibly be defended should be so well guarded that it is virtually impregnable. (3 pages)What mathematics do our students know? What should we teach them?
http://dl-live.theiet.org/content/conferences/10.1049/ic_19970451
In the context of varied engineering student knowledge and attitude, pressure on the curriculum, and pressure on universities to justify their teaching methods and drop-out rates, many institutions are seeking better knowledge of what their students actually know on entry. Such diagnostic testing has several aims: to inform course and curriculum design and delivery; to identify groups in need of remedial treatment; and to inform each student of their own remedial needs. There are a number of schemes of testing in use. Many courses have paper-based tests (including self-assessments), but increasingly lecturers are seeking computer-based facilities to deliver rapid results to large numbers of students, to provide data for analysis of selection, progression, etc., and to act as a 'front-end' to tutorial packages or texts. These computer-based facilities include those built-in to tutorial packages (Sunderland's CALC system, CALMAT, Mathwise) and stand-alone tests (Brunel, based on Question Mark, Nottingham, and DIAGNOSYS, a knowledge-based system originating at Newcastle). What we teach comes into four categories: remedial teaching, especially in the first term of a course; foundation courses; first year courses; and subsequent needs, both higher maths courses and other engineering and science subjects. (3 pages)