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The article presents a method of generating key performance indicators related to electric motor energy efficiency on the basis of Big Data gathered and processed in a frequency converter. The authors proved that using the proposed solution, it is possible to specify the relation between the control mode of an electric drive and the control quality-energy consumption ratio in the start-up phase as well as in the steady operation with various mechanical loads. The tests were carried out on a stand equipped with two electric motors (one driving, the other used to apply the load by adjusting the parameters of the built-in brake). The measurements were made in two load cases, for motor control modes available in industrially applied frequency converters (scalar V/f, vector Voltage flux control without encoder, vector voltage flux control with encoder, vector current flux control, and vector current flux control with torque control). During the experiments, values of the current intensities (active and output), the actual frequency value, IxT utilization factor, relative torque, and the current rotational speed were measured and processed. Based on the data, the level of energy efficiency was determined for various control modes.

The article presents a method of generating Key Performance Indicators related to electric motor energy efficiency on the basis of Big Data gathered and processed in frequency converter. The authors proved that using the proposed solution it is possible to specify the relation between the control mode of an electric drive and the control quality-energy consumption ratio in the start-up phase as well as in the steady operation with various mechanical loads. The tests were carried out on a stand equipped with two electric motors (one driving, the other used to apply the load by adjusting the parameters of the built-in brake). The measurements were made in two load cases, for motor control modes available in industrially applied frequency converters (scalar V/f, vector Voltage Flux Control without encoder, vector Voltage Flux Control with encoder, vector Current Flux Control and Vector Current Flux Control with torque control). During the experiments values of current intensities (active and output), the actual frequency value, IxT utilization factor, relative torque and the current rotational speed were measured and processed. Based on the data the level of the energy efficiency was determined for various control modes.

This work introduces a method, based on the DOE experiment, for assessing the risk of negative aeration by obtaining an experimental measure, which was further correlated with a theoretical gas concentration measure intended for mono- or twin-tube hydraulic shock absorber models. The presented results allow a quantitative assessment method to be defined in order to understand and reduce the aeration effects. The methodology of accurately measuring the effects of the aeration phenomenon in order to validate a simulation model of a twin-tube shock absorber is the focal point of this paper. The paper contributes to analytical tools that allow the risk of aeration to be reduced and the shock absorber design to be optimized against this negative effect. Moreover, the correlated theoretical aeration measure, namely the gas concentration parameter, can be used at early design and configuration stages when the shock absolver valve characteristics are adjusted to achieve the required damping force. The paper describes the physics of the aeration phenomenon, experimental set-up and definition of a measurement system in both hardware and software aspects. The approach presented is based on novel algorithmic post-processing of signals to compute the values of a scalar measure for the phenomenon’s qualitative features of interest, using data registered on a dedicated test bench under the controlled variation of device parameters.

In modern industry, the autonomy in responding to threats is a highly valued feature of machines. The ability to quickly collect and process data on the condition of equipment and events in its environment is the basis for many security or alarm solutions. However, some components are excluded from ongoing monitoring due to difficulties in placing and operating sensors in their area. This state of affairs causes diagnostic methods to be developed in the direction of inferring about given damage with limited access to signals clearly related to specific symptoms. One of the elements of Industry 4.0 – a digital twin – may be helpful in this area. The advantages of such a solution can be observed on the example of virtual representation of the toothed belt drive. The publication describes a proposal to use a dynamic model of a device for the induction of information about the behaviour of a flexible transmitting element only on the basis of the recording of the input and output motions in the mechanism under consideration. The transmission is treated as a “black box”, which can be accessed through a computer simulation. This allows one to determine the condition of the toothed belt, which strength translates into the reliability of the machine. The knowledge gained in this way plays a key role in the system of automatic protection against the breaking of the belt. The principles of the intelligent drive and the result of its experimental verification are presented in the publication.

The article contains approach of diagnosis and prognosis of mechatronic drive systems and their components, based on operational state models recorded in the form of digraphs. Assumed approach in the form of the proposed method containing interrelated groups of failures, effects and their causes forced the need of changes of structures of applied algorithms and their adjusting to the adopted diagnostic and prediction models. In addition, the mathematical notation of directed graph structures dedicated to the transformation of diagnostic relationships to prediction dependencies was presented.

This paper demonstrates linear and nonlinear system identification methods based on a first-principles monotube shock absorber model. Two models were considered, namely low- and high-content a priori knowledge first-principles models. Operational data collected during testing of a shock absorber on a servo-hydraulic test rig were used in order to validate the proposed system identification methods and evaluate their accuracy. The proposed approach in system identification has potentials for a wide range of engineering applications such as control of active and semi-active suspension system.

This paper provides a feasibility study regarding experimental PIV (Particle Image Velocimetry) measurements in order to determine a velocity map of the flow developed across the hydraulic shock absorber intake valve. The velocity map is required to validate and calibrate a CFD/FSI model, which is intended to assess the risk of occurrence of aeration/cavitation phenomena. The model allows to reduce the risk at the shock absorber design stage by means of virtual prototyping. The paper presents the developed hydraulic experimental setup and image processing algorithms in order to obtain a velocity map. The initial test results are briefly reported.

The aim of the paper is to propose a method of tuning first-principle model of a general-purpose servo-hydraulic test-rig. The servo-hydraulic test-rig dynamics is a significant contributor considering shock absorber vibrational analyses and tests. Therefore, the derived model reproduces the important operational parameters of the servo-hydraulic test-rig applicable in laboratory tests. The paper provides a system identification case study in the time domain based on the experimental data.

The paper presents possibility of usage the formalism of structural reliability notation with an implementation of directed graphs and reliability functions recorded in accordance with the Perfect Disjunctive Normal Form notation (PDNF). The author presents the mathematical basis used for an identification of internal structures of mechatronic machines and reduction it to the series-connected blocks. The presented method is a hybrid combination of a binary analysis of evaluated reliability functions (stored in the form of matrixes that relate to defined graphs) and blocks with binary inputs and outputs.

The article describes an approach dedicated to a hybrid representation of mechatronic systems combining matrix and block notations. The main attention is focused on the identification of relationships between mechatronic machines in respect of functional reliability (analysed in the form of block and digraph notations) and rules that allow for the simplification of the reliability function in the systems of machines connected in parallel, series and complex arrangement. The author has adopted a functional representation based on system demonstration employing a binary function of reliability in which the equation is determined based on the method for setting minimum paths in the graph (structural representation of each subsystem). The introduced assumption allows reducing any structure to a serial connection of functional blocks. The author of the paper has also described a manner of implementation in real systems. This article does not include the description of the method used for determining the reliability function, but only theoretical assumptions used in case of identifying functional dependencies.

Steps of validation of the testing device which integrate two quality testing channels (symmetrical Poka-Yoke system) have been described in this article. System was required for testing correctness of the welds of sheet metal stampings, which can be produced as two different, evenly balanced objects (left right pieces). Authors attempted to develop the concept and the implementation of double channel Poka-Yoke system in one housing. Main reason for this integration was requirements for saving space and minimizing changeover time. The goal was reached. However the adverse condition that causes an increase in the possibility of making mistakes by service was observed. This condition was eliminated during the optimization process by the changing in construction and logic in the control program of PLC. All of the reasons for that was described in the article. Particular attention was paid to the positioning of the tested elements, optimization of the proximity inductive sensor layout and mistake proof process depended on wrong manipulation of the tested element. Full 3D CAD model of the end conception and physical implementation was shown in the article. The system was developed and still works in the factory.

Development of devices for the automatic control of the state of the elements that are components of cars has been presented in this article. In spite of the diversity-controlled parts authors have identified the essential elements of each of the positions. Each unit is composed of a housing base plate - with a notch adapted to the controlled element skeleton - part responsible for the determination of controlled parts [, electronic control system detail, visual signaling allowing for rapid assessment of the inspection. A noticeable fact is related to the necessity of proper selection of industrial sensor technology for specific applications. The premises, existence of which can cancel the interop control in favor of the final inspection was been shown by the authors. Considering the most popular industrial sensor systems, with respect to the following criteria measuring range, resolution, sensitivity, also an important factor in the selection [ of the actuators and control subsystem has been discussed. Also the general algorithm of the automatic process control with the methodology of Poka-Yoke has been presented.

The influence of a selection of AC drives parameters at start-up and braking phases is discussed in this article. A wide range of possibilities connected with forming of dynamic characteristics of AC motors reveals a large number of industrial applications taking advantage of an inverter control. Enumerated transient states ensure a correct duty of electric drives and coupled elements (e.g. gears, transportation systems and other technical devices). On the other hand a separated set of parameters depends on the required dynamic conditions (considered within criteria connected with assurance of a failure-free operation). Improper fitting of control factors results in electrical damages arises from exceeding the limit value of rated current caused by various factors inter alia excessive drive load, too fast start-up and braking times. A possibility of performance curved forming brings many benefits and risks. The article focuses also an attention on conditions identification required at the stage of the damage prevention of electric drives.

An important aspect raised in the article is the practical application of rules dedicated to Poka-Yoke systems using real industrial automation components that enable detection of defective elements. The article includes also an optimization of the structure of constructed devices for an unambiguous determination of the Poka-Yoke criteria and a minimization of the possibility of random errors made by the employee (or intentionally deceives of sensor systems). Despite clear conditions of the method the authors observed a lack of publications related to the description of the implementation of equipment elaborated in accordance with the presented methodology in industrial applications. This article presents the author's Poka-Yoke system used for a detection of drawpieces made of steel (with welded nuts) which are components of systems of passenger cars.

Authors of this article had to build the Poka-Yoke [ unit for unusual geometry element, which require to use the inductive proximity switches with relatively small diameter and good sensing range. Industrial sensors suppliers putted on to the market new type of sensor named quasi flush or semi flush which fulfill the needs. An article shows the observed influence of the geometry of tested elements for the self-excitation phenomenon of quasi shielded inductive proximity switches. In consequence this phenomenon can cause in false quality control and passing the wrong elements through the Poka-Yoke unit.

The author of this article considers new approach based on operational reliability models, written in the form of matrices and digraphs methods. At a core of the method the author used the theory of systems and their decomposition consistent with the FMEA methodology [, that allows a simplification of the distribution of elements within the system into smaller parts having a greater susceptibility to the error analysis and forecasting of their states. The method mainly refers to decentralized systems, linked via reciprocal relationships (that can be applied to manufacturing work centres, transport lines, etc.), containing subsystems that use the control, power, noise and mass flows streams. Article includes also main assumptions of described method, realizability studies, application areas and significant restrictions.

Author of this article presents an authorship reliability model of a AC-asynchronous drive written in accordance with assumptions of the multilevel prognosis system based on matrices and digraphs methods. Described model take advantage of knowledge gathered from specialists on the basis of their experience. It is worth to stress that parameters of the reliability model of the AC-drive meet the requirements of units utilized in case of distributed drives. Each change of its application range requires a modification of internal parameters, but the functional structure remains without any variations, because presented reliability model has been based on the functional structure. An intention of the author is focused on an elaboration of a collection of reliability models [ of distributed drives components, prepared in accordance with the multilevel system of prognosis based on matrices and digraphs methods. The model has been specified to the level of the independent subsystem. This approach allows the use of this model in the analysis of complex systems, consisting of separated drive subsystems, which meet the requirements of the method. Using multilevel prediction models should be possible in all applications of electric drives, regardless of purpose functions.

Authors of the paper focused on the problem of devising a concept of computer-aided diagnosis system of a centralized PLC control coupled with the distributed drive systems operated by frequency converters via the ProfiBus industrial network. It is worth emphasizing that the presented concept is useful in all automated systems characterized by the PLC centralized control. The paper provides the description of one of the several modules of dedicated software developed by the authors [6].

This paper presents the method of designing a mechatronic system, as a result of an integration. As an example of the integration automation components, in one coherent measuring system, a measurement path for temperature sensors is proposed. A measuring path can be defined as a scale model, which reproduces thermal states of a temperature sensors system, used in real industrial applications. The system is extended by database application based on Access. Taking advantage of an iFIX special database block the temporary values of temperature are recorded in Access database with permanent period of time. The final analysis is performed in an Excel sheet.

The article presents the influence of the position loop gain setting on the position error values of the hydraulic servo drive. Results of the experimental tests have also been compared with the analytically determined gain values. For the tests, servo cylinder has been loaded with the active force of 2500 N, pointed in the direction opposite to the direction of piston rod extension. The result of the experimental tests was the discovery that the accuracy and stability of the servo drive positioning depends not only on the value of Kv factor, but is also influenced by the direction of the active force loading the servo cylinder. In the tested hydraulic servo drive (hydraulic axis controller), the Compax3F controller by Parker Hannifin was used.

The new proposal of the preparing the aid system for industrial network diagnostic has been described in this article. New method, based on aggregation process of subjective marks of reasoning rules from independent experts, which gives back a more objective parameters for faster computing of the reasoning process, has been implemented. Thanks to this the malfunctions of the industrial network can be reduced to minimum and much faster eliminate. As an example the diagnostic process of the AS-interface industrial network has been described. Significant time reduction has been reached.

The modified shortest path algorithm dedicated for a condition prediction of distributed mechatronic systems is shown in this article. From many of available methods the Dijkstra’s algorithm has been selected. Assumed restrictions of the proposed method (graph models containing interrelated groups of failures, effects and their causes) forced the need regarding changes of the structure of applied algorithms and their adjusting to the adopted predictive model. The method for identification and transformation of the current condition in the source vertex of the graph of causes and effects has been also presented by the authors.

The article presents the results of the experimental test of the pressure pulsation propagation across hydraulic line. The tests have been conducted in the form of a complete two-level experiment, having selected the following parameter variables: flexible hose type (1 or 2-wire hose), pressure value in the pressure line, rotational speed of the pump shaft, pressure line length. The series of pressure runs were analysed in frequency domain using FFT method. The results confirmed the prediction that the discharge line should be treated as a hydraulic transmission line (similar to the long transmission line) with distributed parameters, which variously attenuates pressure pulses of different frequencies.

The article presents the results of preliminary experimental analyses of damping pressure pulsation by the hydraulic flexible hoses. The tests have been conducted in the form of a complete two-level experiment, having selected the following parameter variables: flexible hose type (1 or 2-wire hose), pressure value in the pressure line, rotational speed of the pump shaft, pressure line length. The acquired curves have been analysed in time domains. Values of pressure line damping in relation to the dominant pressure peaks have also been determined. The aim of the undertaken tests has been to confirm or overthrow the common belief that the pressure line with flexible hose itself is the sufficient damper of pressure pulsation in a hydraulic pump.

The article includes a description of the validation used for an assessment of accuracy of measured symptoms in case of distributed drives connected via the ProfiBus DP network. Particular attention has been given to acquiring the diagnostic data especially in case of currents intensities in the start-up and braking phases. The authors also raise a problem of the usefulness and precision of measured data obtained with usage of recording methods by means of dedicated system in comparison with the solutions delivered by the manufacturer of examined drives. Presented results of practical measurements contain values based on the registration of output currents of frequency converters and the measured values of current intensities in the motor windings. The described parameters are significant for the evaluation of electrical damages, caused by various factors (including excessive loads, improper selection, etc.).

Prediction of the machinery or process malfunction states is one of the important and challenging task for knowledge engineers. Nowadays it is a common situation, that the reliable companies collect all kind of important knowledge and by the work of knowledge engineers remake it for well known know-how. The problem we would like to solve is touching the area of objective computer-aided engineering systems. The new proposal of the method for judgments of the expert rules collected in the databases which is arbitral in our opinion has been described in this article. New method based on aggregation process of subjective marks of reasoning rules from independent experts, which gives back an more objective parameters for faster computing of the reasoning process. Thanks to this the malfunctions can be reduced to minimum or much faster eliminate.

Modern systems of the industrial processes automation most often are composed of several basic components, among others: controllers (PLCs, regulators, industrial computers, etc.), actuators (electric, pneumatic, hydraulic and their combinations), control and measuring equipment (sensors and detectors), industrial networks and SCADA/HMI systems (Świder & Hetmanczyk, 2009c). Functional subassemblies have been divided into several groups (mechanical elements, electrical and electronic parts, control equipment and software packets). All of the enumerated components are susceptible to failures, therefore, the main problem is an estimation of the trouble-free service period. In the case of individual components the described task is easy, but an analysis of distributed applications defined as a collection of dependent subsystems the reliability function is dependent on all reliability factors assigned to all components (Dhillon, 2002).

Changing the dynamic motion parameters of pneumatic equipment requires control of pressure and the volumetric flow rate. The article presents a study of the impact of setting control parameters and external disturbances on the positioning accuracy of pneumatic rodless double acting actuator. Testing process was carried out at different values of the parameters (adjusted to the actuator) and external loads. The probe mass was selected within guidelines (a cushioning diagram) so that the operating point was placed on the curve of limiting movement speed of the actuator.

Capabilities of modern automation systems, especially in the field of industrial networks applications, encouraging them to favor during the process of developing the automation project [2,3,5]. Extensive network topologies and simplicity and clear structure causing displacement of the classic wiring. The article presents: project workflow for creating laboratory stand based on industrial network and base on it implementing the safety system. The individual steps of the process are described. In addition, the paper presents the main concept for controlling the safety functions of the system.

The work quality of pneumatic actuators can be assessed in terms of multiple criteria. In the case of complex systems with pneumatic actuators retained at end positions (with occurrence of piston impact in cylinder covers) the vibration criteria constitute the most reliable indicators. The paper presents an impact assessment on the operating condition of the rodless pneumatic cylinder regarding to selected vibrational symptoms. On the basis of performed analysis the authors had shown meaningful premises allowing an evaluation of the performance and tuning of end position damping piston movement with usage the most common diagnostic tools (portable vibration analyzers). The presented method is useful in tuning of parameters in industrial conditions.