Robust design of sliding mode control for airship trajectory tracking with uncertainty and disturbance estimation

The robotic airship can provide a promising aerostatic platform for many potential applications.These applications require a precise autonomous trajectory tracking control for airship.Airship has a nonlinear and uncertain dynamics.It is prone to wind disturbances that offer a challenge for a trajectory tracking control design.This paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed parameters.It uses extended Kalman filter(EKF)for uncertainty and disturbance estimation.The estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory tracking.This comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship trajectory.The proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model inaccuracies.The stability and convergence of the proposed method are investigated using the Lyapunov stability analysis.The simulation results show that the proposed method efficiently tracks the desired trajectory.The method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.

Influence of Various Earth-Retaining Walls on the Dynamic Response Comparison Based on 3D Modeling

The present work aims to assess earthquake-induced earth-retaining(ER)wall displacement.This study is on the dynamics analysis of various earth-retaining wall designs in hollow precast concrete panels,reinforcement concrete facing panels,and gravity-type earth-retaining walls.The finite element(FE)simulations utilized a 3D plane strain condition to model full-scale ER walls and numerous nonlinear dynamics analyses.The seismic performance of differentmodels,which includes reinforcement concrete panels and gravity-type and hollowprecast concrete ER walls,was simulated and examined using the FE approach.It also displays comparative studies such as stress distribution,deflection of the wall,acceleration across the wall height,lateral wall displacement,lateral wall pressure,and backfill plastic strain.Three components of the created ER walls were found throughout this research procedure.One is a granular reinforcement backfill,while the other is a wall-facing panel and base foundation.The dynamic response effects of varied earth-retaining walls have also been studied.It was discovered that the facing panel of the model significantly impacts the earthquake-induced displacement of ER walls.The proposed analytical model’s validity has been evaluated and compared with the reinforcement concrete facing panels,gravity-type ER wall,scientifically available data,and American Association of State Highway and Transportation Officials(AASHTO)guidelines results based on FE simulation.The results of the observations indicate that the hollow prefabricated concrete ER wall is the most feasible option due to its lower displacement and high-stress distribution compared to the two types.The methodology and results of this study establish standards for future analogous investigations and professionals,particularly in light of the increasing computational capabilities of desktop computers.

Distribution of Selected Critical Elements in the Carboniferous Coal-bearing Series of the Upper Silesian and Lublin Coal Basins(Poland)

The distribution of selected critical elements in the sedimentary rocks of the Carboniferous coal-bearing series within the Polish Coal Basins is presented.Critical elements such as Be,Mg,Si,P,Sc,V,Co,Y,Nb,In,Sb,La,Ce,Hf,Ta,W,Bi were analysed using inductively-coupled plasma mass spectrometry(ICP/MS).Concentrations of elements such as Sb,Bi,In and,to a slightly lesser extent,Nb,as well as Sc,show average concentrations higher than those from the upper continental crust.The average concentrations of elements like Hf,Mg,P,Y,La,and Ce are slightly lower than in the upper continental crust.Other elements,such as Be,Co,Si,Ta,W and V have average concentrations that are similar,but slightly enriched or slightly depleted,relative to the upper continental crust.The research showed enrichment of some critical elements in the analysed samples,but not high enough that extraction would be economically viable.Statistical methods,which include correlation coefficients between elements and cluster analysis,reveal a strong positive correlation between elements like Be,Bi,Nb,Sc,Ta,W and V.Very high,almost total,positive correlation is also noted between La and Ce.

A framework for computer vision-based health monitoring of a truss structure subjected to unknown excitations

Computer vision(CV)methods for measurement of structural vibration are less expensive,and their application is more straightforward than methods based on sensors that measure physical quantities at particular points of a structure.However,CV methods produce significantly more measurement errors.Thus,computer vision-based structural health monitoring(CVSHM)requires appropriate methods of damage assessment that are robust with respect to highly contaminated measurement data.In this paper a complete CVSHM framework is proposed,and three damage assessment methods are tested.The first is the augmented inverse estimate(AIE),proposed by Peng et al.in 2021.This method is designed to work with highly contaminated measurement data,but it fails with a large noise provided by CV measurement.The second method,as proposed in this paper,is based on the AIE,but it introduces a weighting matrix that enhances the conditioning of the problem.The third method,also proposed in this paper,introduces additional constraints in the optimization process;these constraints ensure that the stiffness of structural elements can only decrease.Both proposed methods perform better than the original AIE.The latter of the two proposed methods gives the best results,and it is robust with respect to the selected coefficients,as required by the algorithm.

Application and comparison of kernel functions for linear parameter varying model approximation of nonlinear systems

In this paper,a comparative study for kernel-PCA based linear parameter varying(LPV)model approximation of sufficiently nonlinear and reasonably practical systems is carried out.Linear matrix inequalities(LMIs)to be solved in LPV controller design process increase exponentially with the increase in a number of scheduling variables.Fifteen kernel functions are used to obtain the approximate LPV model of highly coupled nonlinear systems.An error to norm ratio of original and approximate LPV models is introduced as a measure of accuracy of the approximate LPV model.Simulation examples conclude the effectiveness of kernel-PCA for LPV model approximation as with the identification of accurate approximate LPV model,computation complexity involved in LPV controller design is decreased exponentially.

Use of the finite elements method for modelling the dynamic load impact on hydraulic leg equipped with gas accumulator

Procedures of preparation of numerical analysis,consisting in a simulation of cooperation of three different media: steel,liquid and gas undergoes dynamic load were discussed.Modelling of the initial static load of the mechanical system was presented.By using the MSC.Software products the following exemplary computer simulations were made: dynamic load impact on the hydraulic leg as well as effectiveness of the hydraulic leg protection against overload with help of gas accumulator.

Non-Destructive Testing of Structures Using Optical and Other Methods: A Review

Non-destructive testing (NDT) of structures is one of the most important tasksof the proper maintenance and diagnosis of machines and constructions structuralcondition. NDT methods contribute to the damage tolerance philosophy used in theaircraft design methodology as well as many other operation and maintenance programsof machinery and constructions. The following study is focusing on overviewing animportant group of NDT methods: the optical and other ones, which found broadapplicability in scientific and industrial studies nowadays. The paper discusses theselected most widely applicable methods, namely, visual testing, ultrasonic testing,radiographic testing, infrared thermography as well as electronic speckle patterninterferometry and shearographic testing. Besides the basic principles of testing usingthese methods, their potential applications in various industrial and technologicalbranches are broadly discussed. The analysis as categorization of the NDT methodsprovided in this paper may help in selection of such methods in diagnosis of varioustypes of structures and defects and damage occurring in these structures.

Application of continuous spectra of radii of influence and some other possibilities of generalisation of subsidence trough description

The paper presents some possibilities of improvement in the subsidence trough description in relation to the description provided by influence function methods. These possibilities rely in a new approach to the values of theory parameters. Instead of one value of a certain theory parameter it is assumed that it can vary within an interval (in particular infinite one) and each value within that interval is given a weight. Thus we receive a distribution of the values of the parameter considered analogical to the probability distribution of a random variable.

Health Risk Impacts of Exposure to Airborne Metals and Benzo(a)Pyrene during Episodes of High PM10 Concentrations in Poland

Objective To check whether health risk impacts of exposure to airborne metals and Benzo（a） Pyrene during episodes of high PM10 concentrations lead to an increased number of lung cancer cases in Poland. Methods In this work, we gathered data from 2002 to 2014 concerning the ambient concentrations of PM10 and PM10-bound carcinogenic Benzo（a）pyrene [B（a）P] and As, Cd, Pb, and Ni. With the use of the criterion of the exceedance in the daily PM10 mass concentration on at least 50% of all the analyzed stations, the PM10 maxima’s were selected. Lung cancer occurrences in periods with and without the episodes were further compared. Results During a 12-year period, 348 large-scale smog episodes occurred in Poland. A total of 307 of these episodes occurred in the winter season, which is characterized by increased emissions from residential heating. The occurrence of episodes significantly （P 〈 0.05） increased the concentrations of PM10-bound carcinogenic As, Cd, Pb, Ni, and B（a）P. During these events, a significant increase in the overall health risk from those PM10-related compounds was also observed. The highest probability of lung cancer occurrences was found in cities, and the smallest probability was found in the remaining areas outside the cities and agglomerations. Conclusion The link between PM pollution and cancer risk in Poland is a serious public health threat that needs further investigation.

New View of Ping-Pong Protocol Security

The ping-pong protocol offers confidential transmission of classic information without a prior key agreement.It is believed that it is quasi secure in lossless quantum channels.Serious doubts related to the analysis paradigm which has been used so far are presented in the study.The security of the protocol is reconsidered.

Poetic Wisdom, Mind and Senses, Media. How to Deal With Phenomenon of Crisis of Humanities？

The today culture seems to be tom by two contradicted phenomena. First is connected with crisis of humanities, second with stepping of arts into the new spheres. Based on the thought of Marshall McLuhan, Giambatistta Vico and Rudolf Arnheim we will display that this contradiction is only apparent. After Marshall McLuhan we acknowledge the power of media to change the pattems of cognition and after RudolfArnheim we acknowledge the intimate relation between senses and mind. On such foundation we will see that crisis of humanities is connected with incorrect understanding relation between mind and senses. As Rudolf Arnheim remarks strict division between senses and mind favors downgrading social role of art and humanities--such division refuses art and humanities right to take a part in cognition. But in the age of electronic/digital culture, which is recovering the simultaneous of the verbi-voco-visual communication, new proportion between our senses is appearing. It must entail new approach to art and humanities.

Measurement of Mechanical Properties of Carbon, New Devices

Proper selection of machines and equipment used in underground coal mining significantly influence the increase of their durability and reliability. The paper describes new, created in Poland devices to determine and evaluate the mechanical properties of the carbon （workability） whose co-founder is the author of this paper. These devices reflect the nature of the work of a plough and drum cutter-loader. It is presented their construction, operating principles as well as innovation and originality of used solutions. The devices are certified by enabling them to work in conditions of real mines, as a device intended for use in potentially explosive atmospheres. These devices have been awarded medals and diplomas at many International Fairs and Technological Innovation Exhibitions.

Comparison Research of Bed Joints Construction and Bed Joints Reinforcement on Shear Parameters of AAC Masonry Walls

The work presents the results of tests on the shear parameters of walls made of AAC （autoclaved aerated concrete, fb = 4.0 N/mm2） on the system mortar for thin M5 and M10 joints （fm = 6.1 N/mm2 and fro = 11.9 N/mm2） and on polyurethane glue and also walls without mortar （dry masonry）. The wall compression strength （on mortar M5 class） （per EN 1052-1：2000） amounted tofc,mv= 2.97 N/mm2 （fk = 2.48 N/mm2）, elastic modulus was Ecru = 2,040 N/mm2. Various structure of bed joints and head joints were applied and the following were used as reinforcement： steel trusses of EFZ 140/Z 140 type （Z1 type） and meshes made of plastics （Z2 type）. Based on the tests carried out with regard to unreinforced elements, it was shown that the filling in of head joints with mortar had an advantageous effect on the values of cracking and destruction stresses. While, with the use of reinforcement, advantageous increase of stress was obtained only when the mortar was laid twice on both bed surfaces of masonry units. The application of reinforcement in the bed joints when the mortar was laid only on one bed joints surface of the masonry units reduced the values of cracking and destruction stresses in relation to the values obtained in the unreinforced walls.

The Study Urban Context, the Development and Promotion of Industrial Tourism： Example of the Nord-Pas de Calais in France

The ongoing processes of spatial transformation of post-industrial regions attract people＇s attention, and they show new possibilities of development but they are also related with new challenges. A deep analysis of known patterns must be an important lesson as, first of all, we observe transformation of other regions, which gives rise to a question about the possibility of using positive model solutions in other urban contexts. Moreover, in every action contributing to the development of a region with traditions, we should use every potential, understood as accumulated energy and closed in facilities, individuals and their mutual relations. The article is divided into five parts： （1） a short history of Nord-Pas de Calais; （2） a significant introduction to history and spatial issues; （3） a description of corrective measures undertaken on the basis of, e.g., an urban analysis from the moment of taking a decision on ceasing coal mine extraction until today; （4） a description of＂a concept for the region＂; （5） conclusions---including a catalogue of actions, prepared by the author, where an important aspect will be the use of elements of spatial values and spatial identity of regions in the process of planning spatial, social and economic transformation. In the article, the results of studies conducted in years 2010-2015, based on statistical data analysis, strategic documents analysis and an on-site visit are presented.

Modern Control and Diagnostic System of Traction Vehicle with Hybrid Drive System

In paper it introduced a review of modem traction vehicle drive system with induction motor drive system （PMSM with single or dual rotor drive system） or BLDC motor with different configuration of magnetic circuits. For particular part of drive system proposed a quasi intelligent control system version smart control enables multi criteria predictive control of vehicle work. In the paper presented also a selected diagnostic procedure, enables monitoring exploitation parameters, and prediction of probable failure state. For different vehicle work state realized a simulation models and crash test of exploitations failure models.

Modern Electrical Power Source on New System of Dissipation and Renewable Energies Sources

This paper presents some solutions of modem renewable energy system applied actually in dissipation energy source： wind turbine, solar panel battery charge, SSS （support set system）, and standby diesel generator cooperated in series, parallel and hybrid system with main energy system. Its solution enable obtain independent individual energy source in different work exploitations. One of problems concerned with alternative energy source is changes of output voltages and output power dependence of climatic conditions. Possible solution is application of decoupled adjustable speed generation system in renewable energy generation. The decoupled generation system consists of： alternative energy source, internal combustion engine drives permanent magnet generator and DC/AC, or AC/AC converter. Performance of single decoupled generation set is discussed supported by results of laboratory tests. To provide high quality voltage is applied an additional energy storage, made from super capacitor and bidirectional DC/DC convert. Such system performs very stiff voltage in any load condition. Integration of solar battery panels or renewable wind energy system is provided via DC link of the variable speed decoupled autonomous generation system. Results of computer simulation and laboratory experiments are presented in the paper.

Quasi Dynamic Model of Wheel Vehicle with Electric and Hybrid Drive System

The paper presents physical and mathematical models of kinetic system, drive system （electric and combustion traction motors）, and also wheel and rails traction vehicle supply system （car, special vehicle, modern tram vehicle）. Selected predictive and quasi dynamic control system algorithms of traction vehicle are presented in the paper. For selected constructions of traction vehicle drive system are presented in simulation models and are results of calculations of different exploitations work state of wheel vehicle with hybrid drive system. Results of computer calculations are verified with laboratory measurement and suitable corrections coefficient to simulations models of vehicles is introduced.

Modern Predictive Diagnostic Method of Induction Traction Motor Based on FEM, BEM

The paper presents a mathematical model of special construction induction traction motor. On the base of predictive filtering, analytical studies, fuzzy logic control, relying on the virtual data generated by FEM （Finite Element Method） and BEM （Boundary Element Method） is detected faults of induction motor. Digital predictive filter is used to separate a fundamental harmonic from spectrum current and voltage harmonics. Fuzzy logic control is used to identify a motor state. Magnetic fields distribution in the traction motor, of the wheel vehicle is presented in the paper. Modem diagnostics method has been used for faulty motor simulation and shows results of motor fault effects. Some computer programs were applied in calculation of magnetic fields distribution. On the base of magnetic field distributions were analyzed different failures situations. Some laboratory experiments realized for induction traction motor were verified by results of computer calculations.

Durability of Stress Ribbon Bridge Checked during Loading Test

Stress ribbon bridges have many advantages and became recently more popular mostly because of their versatile form, slender decks giving a light aesthetic impression and durability assured by post tensioned concrete. The paper presents the first in Poland stress Ribbon Bridge constructed last year. A static and dynamic analyse of the model is presented as well as construction solutions which were used to achieve the highest durability. The bridge was checked during static and dynamic load test. The results of this prove test were compared with results obtained from examination and study of other different bridge structures. It confirmed that the bridge has good dynamic resistance and greater stiffness than assumed in the design.

Prediction of Losses in Flow Through the Last Stage of LP Steam Turbine

The aim of presented work was the prediction of the losses in the wet steam flow through the last stage of 200MW steam turbine LP part.To this end,three numerical tools were used.The first method was the streamline curvature method (SCM) used on the meridional plane with losses correlations.The next two methods,TASCflow commercial CFD code and an in-house CFD code,based on the solution of the Reynolds- averaged Navier-Stokes equations (RANS).Ap- plication of three independent numerical tools al- lowed to make the more reliable losses analysis and made possible to compare applied numerical methods with each other. For the flow modeling in the last stage of LP steam turbine the various two-phase flow models were used and compared.The equilibrium model and non-equi- librium models with homogeneous and/or heterogeneous condensation were considered.The boundary conditions at the inlet and outlet from the stage were selected in such way to get the beginning of the homogeneous condensation process in the sta- tot.It corresponded to the part load of the turbine, i.e.140MW power and pressure in condenser 2.7kPa.