Automation in experiments carried out on animals is getting more and more important in research. Computers take over laborious and time-consuming activities like recording and analysing images of the experiment scene. The first step in an image analysis is finding and distinguishing between the observed animals and then tracking all objects during the experiment. In this paper four tracking methods are presented. Quantitative and qualitative figures of merit are applied to confront those methods. The comparison takes into consideration the level of correct object recognition during different disturbances, the speed of computation, requirements as to the frame rate and image illumination, quality of recovering from occluded situations and others.

The paper presents a new method for simultaneous tracking of varying grid impedance and its uncertainty bounds. Impedance tracking consists of two stages. In the first stage, the actual noise estimate is obtained from least squares (LS) residua. In the second stage, the noise covariance matrix is approximated with the use of residual information. Then weighted least squares (WLS) method is applied in order to estimate impedance and background voltage. Finally uncertainty bounds for impedance estimation are computed. The robustness of the method has been verified using simulated signals. The proposed method has been compared to sliding LS. The results have shown, that the method performs much better than the LS for all considered cases, even in the presence of significant background voltage variations.

The contribution presents a novel approach to the detection and tracking of lanes based on lidar data. Therefore, we use the distance and reflectivity data coming from a one-dimensional sensor. After having detected the lane through a temporal fusion algorithm, we register the lidar data in a world-fixed coordinate system. To this end, we also incorporate the data coming from an inertial measurement unit and a differential global positioning system. After that stage, an original image of the road can be inferred. Based on this data view, we are able to track the lane either with a Kalman filter or by using a polynomial approximation for the underlying lane model.

The paper addresses optimal control problem of mobile manipulators. Dynamic equations of those mechanisms are assumed herein to be uncertain. Moreover, unbounded disturbances act on the mobile manipulator whose end-effector tracks a desired (reference) trajectory given in a task (Cartesian) space. A computationally efficient class of two-stage cascaded (hierarchical) control algorithms based on both the transpose Jacobian matrix and transpose actuation matrix, has been proposed. The offered control laws involve two kinds of non-singular terminal sliding mode (TSM) manifolds, which were also introduced in the paper. The proposed class of cooperating sub-controllers is shown to be finite time stable by fulfilment of practically reasonable assumptions. The performance of the proposed control strategies is illustrated on an exemplary mobile manipulator whose end-effector tracks desired trajectory.

Figuig Berber (eastern Morocco) has a large number of deictic constructions. Among these, a construction with a preposed pronominal element followed by a genitival phrase is by far the most common. All deictic constructions use a basic contrast between two elements: -u and -ənn. In exophoric deixis, the former has proximal interpretation, while the latter has distal interpretation. In endophoric deixis, the situation is more complicated. For some speakers, only constructions with -ənn are permitted in this use, while other speakers use both constructions with -u and -ənn, without clear contrast. In the article, emphasis is laid on when endophoric deictic marking is used, and when it is absent. In principle, such marking shows that the referent has already been mentioned in the previous context, and can be regarded anaphoric. However, in such situations, it is still possible not to mark the noun. This is mainly the case when there is only one potential referent in a given situation, as, for example, in the case of kings, or as is often the case with nouns modified by a genitival phrase.

Eye tracking constitutes a valuable tool for the examination of human visual behavior since it provides objective measurements related to the performed visual strategies during the observation of any type of visual stimuli. Over the last decade, eye movement analysis contributed substantially to the better understanding of how visual attention processes work in different types of maps. Considering the clear need for the examination of map user reaction during the observation of realistic cartographic products (i.e. static maps, animated maps, interactive and multimedia maps), a critical amount of experimental studies were performed in order to study different aspects related to map reading process by the cartographic community. The foundation of these studies is based on theories and models that have been developed in similar research domains (i.e. psychology, neuroscience etc.), while the research outcomes that produced over these years can be used directly for the design of more effective and efficient maps. The aim of the present article is to summarize and present the current panorama of the existing eye tracking studies in cartographic research appeared over the last decade. Additionally, methodological contributions (including analysis tools) of cartographic society in the field of eye movement analysis are reported, while existing challenges and future perspectives are also discussed.

Focus of the vibration expert community shifts more and more towards diagnosing machines subjected to varying rotational speeds and loads. Such machines require order analysis for proper fault detection and identification. In many cases phase markers (tachometers, encoders, etc) are used to help performing the resampling of the vibration signals to remove the speed fluctuations and smearing from the spectrum (order tracking). However, not all machines have the facility to install speed tracking sensors, due to design or cost reasons, and the signal itself has to then be used to extract this information. This paper is focused on the problem of speed tracking in wind turbines, which represent typical situations for speed and load variation. The basic design of a wind turbine is presented. Two main types of speed control i.e. stall and pitch control are presented,. The authors have investigated two methods of speed tracking, using information from the signal (without relying on a speed signal). One method is based on extracting a reference signal to use as a tachometer, while the other is phase-based (phase demodulation). Both methods are presented and applied to the vibration data from real wind turbines. The results are compared with each other and with the actual speed data.

Condition monitoring of machines working under non-stationary operations is one of the most challenging problems in maintenance. A wind turbine is an example of such class of machines. One of effective approaches may be to identify operating conditions and investigate their influence on used diagnostic features. Commonly used methods based on measurement of electric current, rotational speed, power and other process variables require additional equipment (sensors, acquisition cards) and software. It is proposed to use advanced signal processing techniques for instantaneous shaft speed recovery from a vibration signal. It may be used instead of extra channels or in parallel as signal verification.

The research project “Railcab” designs a shuttle-based transportation system, which combines innovative mechatronic technologies with existing railway tracks. The traction and braking forces are generated by a linear electromagnetic drive while the tracking and guidance is performed using classical wheel/rail technology. By adopting different mechatronic modules, a modular structuring of the overall system, the driving safety, vehicle dynamics and the travelling comfort can be increased.

In the present paper, we concentrate on the development of the active tracking module which reduces the sensitivity of the system behaviour with respect to the friction in the wheel/rail contact. Basic ideas of the tracking module are self-optimizing active tracking, camber adjustment, and mechanical locking device. Based on a-priori identified risks, like e.g. strong cross-wind, frosted rails and crossing of switches, the safety concepts are described in detail together with the methodology that was used in the design process.

The paper presents design and experimental verification of platform mechanism with cost-effective wire-based sensors for measuring of spatial displacement or pose of some moving object. This task, also known as spatial tracking, has a very wide application. The proposed mechanism, guided by the moving object, has a parallel structure with two platforms and at least six wire-based sensors for measuring distances between the platform points. Changes of the platform pose cause corresponding changes of the sensors' wire lengths. Forward position problem of an equivalent mechanism model with 6 degrees of freedom is described together with analyses of work space limitations and error propagation in a measurement system. A specific application is illustrated for tracking of a wheel knuckle of 5-link suspension mechanism used in passenger cars. The developed device has the following advantages: it can be installed in a wheel cavity; enables dynamic measurements on the road; is cost-effective. Performance of the latest prototype of the wire-based tracker was verified on the basis of measurements on a test rig, where two other measuring devices were used for comparison purposes.

The diagnostics of track superstructure, which involves geometric measurements, direct observation and railroad surveillance, provides the basis for making decisions regarding the commencement of repair works. Planning repairs and increasing the probability of making the right decision at the right time also requires knowledge of the basic performance specifications of a given railway line, especially the maximum train speed and the permissible traffic volume. The article discusses a way to plan the repairs of track superstructure using artificial neural networks. It features a description of the process of designing, building and training a neural network, based on which a way to predict the degree of urgency of repairs has been discussed. The conclusions point towards the potential advantages of neurocomputers in the process of track superstructure maintenance.

Photovoltaic (PV) cells are very costly because of the silicon element which is not cheaply available. Usually, PV cells are preferred to be used at maximum efficiency. Therefore, PV plants are emphasized to extract maximum power from PVcells. When inertia free PV plants are integrated into the grid in large numbers, the problem of maintaining system stability subjected to load perturbation is quite difficult. In response to this, a control topology is being an approach to make available the PV cells in maintaining system stability by utilizing the system frequency deviation as feedback to the controller. To implement this, the PVs are operated at Maximum Power Point Tracking (MPPT). This allows the PV to operate at Pseudo Maximum Power Point tracking (PMPPT) which makes it possible to run the PV with reserve power capacity without employing a battery for storage. The control strategy has been implemented over a two-stage power conversion model of the PV system. The simulation results showed that the proposed control PMPPT topology is effective in frequency regulation capability as compared to the MPPT technique.

In this paper we propose a sensor-based navigation method for navigation of wheeled mobile robot, based on the Kohonen self-organising map (SOM). We discuss a sensor-based approach to path design and control of wheeled mobile robot in an unknown 2-D environment with static obstacles. A strategy of reactive navigation is developed including two main behaviours: a reaching the middle of a collision-free space behaviour, and a goal-seeking behaviour. Each low-level behaviour has been designed at design stage and then fused to determine a proper actions acting on the environment at running stage. The combiner can fuse low-level behaviours so that the mobile robot can go for the goal position without colliding with obstacles one for the convex obstacles and one for the concave ones. The combiner is a softswitch, based on the idea of artificial potential fields, that chooses more then one action to be active with diRerent degrees at each time step. The output of the navigation level is fed into a neural tracking controller that takes into account the dynamics of the mobile robot. The purpose of the neural controller is to generate the commands for the servo-systems of the robot so it may choose its way to its goal autonomously, while reacting in real-time to unexpected events. Computer simulation has been conducted to illustrate the performance of the proposed solution by a series of experiments on the emulator of wheeled mobile robot Pioneer-2DX.

In this work, a novel approach to designing an on-line tracking controller for a nonholonomic wheeled mobile robot (WMR) is presented. The controller consists of nonlinear neural feedback compensator, PD control law and supervisory element, which assure stability of the system. Neural network for feedback compensation is learned through approximate dynamic programming (ADP). To obtain stability in the learning phase and robustness in face of disturbances, an additional control signal derived from Lyapunov stability theorem based on the variable structure systems theory is provided. Verification of the proposed control algorithm was realized on a wheeled mobile robot Pioneer–2DX, and confirmed the assumed behavior of the control system.

Recently, the search for new effective energy production solutions has been focused on the production of electricity using renewable and environmentally friendly carriers. This resulted in an increased interest in PV cells and cogeneration systems. The article looks at the main factors affecting their operational parameters against the background of the development history of subsequent generations of PV cells. Average daily solar radiation and wind velocity in Lodz were characterized. The research was done on a static and tracking system with a total peak power of 15 kWp and a 30 kW microturbine. PV panels are installed on the building of the Institute of Electrical Power Engineering of the Lodz University of Technology and they work as part of DERLab. A microturbine is inside the building. Energy measurements were carried out in 2016 giving grounds for the analysis of energy efficiency and financial analysis of the energy supply in buildings. Energy yields in the static and tracking system as well as percentage coverage of electricity from PV cells and microturbines were assessed. The distribution of monthly savings, annual savings of energy costs and the payback time of the investment costs of the systems subject to the test were determined. The research we have done allows us to say that the energy produced by follow-up modules is about 3 times greater than that generated in stationary modules. On the other hand, the annual savings of energy costs using gas micro-turbines are about 10 times higher than those of lagging panels. The analysis shows that it is possible to determine the profitability of the microturbine and photovoltaic panels use despite large financial outlays. The payback period of investment outlays is about 12 years when using the installation throughout the year.