Experiences with mechatronics education at the University of Twente

This paper describes the experiences with a number of variants of mechatronic programmes offered by the University of Twente since 1989. Mechatronics education took place in a two-year mechatronic designer programme, in specialisations in Electrical and Mechanical Engineering and in an international MSc programme. In the new European BSc/MSc structure the University of Twente will offer an MSc mechatronics where the course language will be English. There have been large mechatronic projects, where 4 PhD and some 50 MSc students did their thesis work as well as two-week mechatronic projects in the BSc curricula of EE and ME. The latter show that mechatronics is not only a topic of interest for students who want to specialise in this direction, but that mechatronic projects also offer a challenge for electrical and mechanical engineering students in general

A MRAS-based Learning Feed-forward Controller

Inspired by learning feed–forward control structures, this paper considers the adaptation of the parameters of a model–reference based learning feed–forward controller that realizes an inverse model of the process. The actual process response is determined by a setpoint generator. For linear systems it can be proved that the controlled system is asymptotically stable in the sense of Liapunov. Compared with more standard model reference configurations this system has a superior performance. It is fast, robust and relatively insensitive for noisy measurements. Simulations with an arbitrary second–order process and with a model of a typical fourth–ordermechatronics process demonstrate this

Mechatronic Design: A Port-Based Approach

In this paper we consider the integrated design of a mechatronic system. After considering the different design steps it is shown that a port-based approach during all phases of the design supports a true mechatronic design philosophy. Port-based design enables use of consistent models of the system throughout the design process, multiple views in different domains and reusability of plant models, controller components and software processes. The ideas are illustrated with the conceptual and detailed design of a mobile robot

Robust tracking control of two-degrees-of-freedom mobile robots

A robust tracking controller for a mobile robot with two degrees of freedom has been developed. It is implemented and tested on a real mobile robot. Where other controllers show decreasing performance for low reference velocities, the performance of this controller depends only on the geometry of the reference trajectory. This allows accurate positioning at low speeds, close to obstacles. The dynamics of the velocity-controlled mobile robot are considered as perturbed unity transfer from input velocity to actual velocity. It is shown that the tracking controller is robust with respect to these perturbations

Mechatronics at the University of Twente

This paper describes some of the mechatronics activities at the University of Twente. In 1989, the founding of the Mechatronics Research Center Twente started a cooperation of the departments of Electrical Engineering, Mechanical Engineering, Applied Mathematics and Computer Science. The mechatronics activities get especially attention in projects in the Ph.D. programme and in the `mechatronic designer' program, but Msc. students participate as well. As an illustration of the philosophy behind the work at the University of Twente and of the activities carried out so far, the paper describes two projects of the institute: the MART (Mobile Autonomous Robot Twente) project and the ALASCA (Automated Laser Aided Servo Controlled Assembly) projec

A Novel Decomposition for Control of DC Circuits and Grid Models with Heterogeneous Energy Sources

The way in which electric power depends on the topology of circuits with mixed voltage and current sources is examined. The power flowing in any steady-state DC circuit is shown to depend on a minimal set of key variables called fundamental node voltages and fundamental edge currents. Every steady-state DC circuit can be decomposed into a voltage controlled subcircuit and a current controlled subcircuit. In terms of such a decomposition, the I^2R losses of a mixed source circuit are always the sum of losses on the voltage controlled subcircuit and the current controlled subcircuit. The paper concludes by showing that the total power flowing in a mixed source circuit can be found as critical points of the power expressed in terms of the key voltage and current variables mentioned above. The possible relationship to topology control of electric grid operations is discussed

Rudder roll stabilization for ships

This paper describes the design of an autopilot for rudder roll stabilization for ships. This autopilot uses the rudder not only for course keeping but also for reduction of the roll. The system has a series of properties which make the controller design far from straightforward: the process has only one input (the rudder angle) and two outputs (the heading and the roll angle); the transfer from rudder to roll is non-minimum-phase; because large and high-frequency rudder motions are necessary, the non-linearities of the steering machine cannot be disregarded; the disturbances caused by the waves vary considerably in amplitude and frequency spectrum.\ud \ud In order to solve these problems a new approach to the LQG method has been developed. The control algorithms were tested by means of computer simulations, scale-model experiments and full-scale trials at sea. The results indicate that a rudder roll stabilization system is able to reduce the roll as well as a conventional fin stabilization system, while it requires less investments. Based on the results obtained in this project the Royal Netherlands Navy has decided to implement rudder roll stabilization on a series of ships under construction at this moment

Learning feedforward controller for a mobile robot vehicle

This paper describes the design and realisation of an on-line learning posetracking controller for a three-wheeled mobile robot vehicle. The controller consists of two components. The first is a constant-gain feedback component, designed on the basis of a second-order model. The second is a learning feedforward component, containing a single-layer neural network, that generates a control contribution on the basis of the desired trajectory of the vehicle. The neural network uses B-spline basis functions, enabling a computationally fast implementation and fast learning. The resulting control system is able to correct for errors due to parameter mismatches and classes of structural errors in the model used for the controller design. After sufficient learning, an existing static gain controller designed on the basis of an extensive model has been outperformed in terms of tracking accuracy

15 years of experience with mechatronics research and education

This paper describes the experiences with mechatronic research projects and several educational structures in the University of Twente since 1989. Education took place in a two-year Mechatronic Designer programme, in specialisations in Electrical and Mechanical Engineering and in an (international) MSc programme. There are two-week mechatronic projects in the BSc curricula of EE and ME. Many of the PhD and MSc projects were done in projects sponsored by the industry or by application-oriented research programs. Research topics included modelling and simulation (learning) control, embedded systems and mechatronic design

Development of a nucleic acid lateral flow immunoassay for simultaneous detection of Listeria spp. and Listeriamonocytogenes in food

We present a new nucleic acid lateral flow immunoassay (NALFIA) for the assessment of listeria contamination. The detection procedure starts with enrichment of sample in Half Fraser broth (24 h). Following isolation of DNA, a duplex PCR is performed with two labelled primer sets, one generic and directed to a specific sequence of the gene encoding 16S rRNA from Listeria spp. and the other specific and directed to a part of the prfA gene encoding the central virulence gene regulator from the food pathogen Listeria monocytogenes (3.5 h). The PCR solution is directly added to the one-step assay device and the appearance of a grey/black line is indicative of the presence of specific amplicons (max 15 min). In all tests performed, the method correctly identified L. monocytogenes and strains of Listeria spp. PCR material of over 20 food samples was tested by NALFIA. The method proved to be useful for the detection of L. monocytogenes in different kinds of food sample