Harun Šiljak

A novel algorithm for following of moving target in outdoor mobile robot environment based on inverse matching

This paper proposes a new algorithm for following a mobile robot target in an outdoor environment. This approach combines a fuzzy tracking control law and an inverse matching based algorithm for finding and following of the moving target. The inverse matching algorithm comprises local maps of a robot environment to identify the target and generate desire path toward it. The localization of the mobile robot is done by the triangulation method based on GPS measurements. In addition, previously developed software system for the mobile robot enables GPS guidance and obstacle avoidance which makes it suitable for creation of mobile convoys. Finally, the experimental verification is performed to confirm the effectiveness and practical value of the proposed approach.

Sensor fusion for Solar Car Route Optimization

This paper focuses on sensor data management in the Solar Car Optimized Route Estimation (SCORE) system which is currently being developed. The data collection is split into two phases: the a priori phase related to the environment and the real time phase related to the solar vehicle. The hardware and software architecture for a priori phase is illustrated in detail, while the real time phase is discussed as a part of the embedded car computer. The full system description for SCORE is presented with guidelines for the future work and implementation of it.

Criteria for Solar Car Optimized Route Estimation

Abstract This paper gives a thorough overview of Solar Car Optimized Route Estimation (SCORE), novel route optimization scheme for solar vehicles based on solar irradiance and target distance. In order to conduct the optimization, both data collection and the optimization algorithm itself have to be performed using appropriate hardware. Here we give an insight to both stages, hardware and software used and present some results of the SCORE system together with certain improvements of its fusion and optimization criteria. Results and the limited applicability of SCORE are discussed together with an overview of future research plans and comparison with state-of-the-art solar vehicle optimization solutions.

Berthil cepstrum: a novel vibration analysis method based on marginal Hilbert spectrum applied to artificial motor aging

Motor age determination as a part of condition monitoring heavily employs vibration analysis. This study introduces a new method for such analysis, based on concepts of cepstrum and marginal Hilbert spectrum. This new method, named Berthil cepstrum, may be applied in general signal processing, not only when vibration signals are concerned. Classical marginal Hilbert spectrum has also been applied to the artificial motor aging data with excellent results. Furthermore, a ranking of known spectrum-based methods for determination of motor age together with the new methods introduced in this study has been made based on SVM and RELIEF attribute ranking, showing quality of the new methods.

Practical implementation of solar car optimized route estimation

Solar Car Optimized Route Estimation (SCORE) has been proposed in an earlier publication as an alternative navigation principle for solar cars, conducting route optimization based on both distance and solar irradiance data. This paper gives details about the implementation and discusses results of SCOREs use, suggesting possible limitations and future research directions. The results show limited applicability of solar irradiance data for route optimization, but suggesting that parking place selection is an important aspect that needs to be taken care of. The implementation uses both a MATLAB testbed application and C/C++ code for TIs ARM Cortex-M4F based TM4C123G LaunchPad, and the final version of the SCORE client is placed in a custom built solar vehicle. Combined with the previously developed server for sensor data collection and data processing and sensor transmitter infrastructure for solar irradiation, the route optimization system is fully operational.

INVERSE MATCHING-BASED MOBILE ROBOT FOLLOWING ALGORITHM USING FUZZY LOGIC

This paper introduces the novel concept of inverse matching in case of mobile target following, as well as a new algorithm based on merging this concept with elements of fuzzy control. Previously developed hardware and software are combined to produce a functional mobile robot convoy system. Test results of this localization, fuzzy control and inverse matching fusion show the effectiveness as well as practical value of the approach proposed for autonomous robot

Hardware implementation of auto-mutual information function for condition monitoring

Abstract This study is aimed at showing the applicability of mutual information, namely auto-mutual information function for condition monitoring in electrical motors, through age detection in accelerated motor aging. Vibration data collected in artificial induction motor experiment is used for verification of both the original auto-mutual information function algorithm and its hardware implementation in Verilog, produced from an initial version made with MATLAB HDL (Hardware Description Language) Coder. A conceptual model for industry and education based on a field programmable logic array development board is developed and demonstrated on the auto-mutual information function example while suggesting other applications as well. It has also been shown that attractor reconstruction for the vibration data cannot be straightforward.

An extended model of a level and flow control system

FESTO Compact Workstation is a well known didactic tool in process control. This paper aims at providing an improved transfer function model of this systems level and flow control loops. This higher order model is compared to existing first order system approximations of the level control loop in various input-output scenarios to verify its applicability and superiority. Results are obtained using MATLAB System Identification Toolbox after data acquisition in LabVIEW. MATLAB Simulink is used for cascade PI and single loop PI experiments to show the improvement cascade control on the new model brings. Together with the practical value the results have, the procedure conducted here can serve as a primer and a tutorial for system identification class using this or similar apparatus.

Murder on the Einstein Express

I have always enjoyed writing. The fact I am not good at it couldn’t stop me, since I had the will and thought it’s enough. However, the publishers would soon prove me wrong. What I hated the most was the repeated rejection of a story about thought experiments in physics I was so proud of. Sci-Fi editors didn’t understand it, scientists thought it was inappropriate, so it had no place to go.

Weak limits and their calculation in analog signal theory

Purpose – This paper aims to improve the mathematical justification of certain analog signal theory concepts and offer a rigorous framework for it.Design/methodology/approach – The framework relies on functional analysis, namely theory of distributions and the concept of weak limit. Its notation is adjusted to resemble the notation usually used in engineering signal theory. It can be used to prove in a rigorous manner already established results in signal theory, but also to establish new ones.Findings – Examples have shown the lack of rigour caused by using ordinary calculus in proving fundamental signal theoretic results. On that basis, concepts of limit, Fourier transform and derivative are revisited in the spirit of functional analysis. A new useful formula for weak limit computation is proved.Originality/value – Functional analysis is efficiently used in signal theory in a manner approachable by engineers. An original and efficient formula for weak limit computation is presented and proved.