Electrical Mechanical Systems Research Articles

Dynamic characteristics of electromechanical coupling of body-suspended drive system for high-speed trains under wheel polygonal wear

Wheel polygonal wear can trigger intense wheel–rail interactions in railway vehicles, posing a significant threat to traffic safety. However, the mechanism and interaction of the influence of wheel polygonal wear on the electromechanical coupling characteristics of high-speed trains remain unclear. Therefore, this paper proposes a joint simulation modelling method that takes into account the integration of the electrical subsystem with the complete mechanical subsystem. A comprehensive analysis is conducted on the dynamic response of the high-speed train’s body-suspended drive system under a wide range of frequency excitations arising from harmonic torque, gear meshing, and wheel polygon wear. The results indicate that the electrical system generates a substantial amount of harmonic frequency components, resulting in a significant increase in the vibration of the train. The wheel polygon wear causes a broadening of the low-frequency resonance band, revealing a relatively prominent observation interval for the dynamic characteristics. Concurrently, it is discovered that the 23rd-order wheel polygon wear excites the system’s resonance frequency, and as the wavelength of the wheel polygon increases, the acceleration vibrations intensify progressively. Research reveals first the interaction of electrical system and mechanical system under wheel polygon wear, especially in the resonance gain characteristics under polygons and harmonic torques.

Process capability of electrochemical discharge machining: A review

Electrochemical discharge machining (ECDM) is a hybrid machining formed by combining the principles of electrochemical machining and electrical discharge machining. The ECDM is unconventional micromachining that can fabricate holes, blind holes, micro-cavities and grooves on brittle insulating materials such as quartz, glass, silicon wafers and different composites that are difficult to machine. These non-conducting materials have sundry applications such as Micro Electric-Mechanical Systems, biomedical and electronics items. The ECDM provides maximum material removal rate and good surface quality with minor tool wear. The study describes how different process parameters affect machining. The assessment mainly focuses on various tool electrode geometries and materials that are used in ECDM. The present article investigates the ramifications of different types of electrolytes and additives mixed in electrolytes used during the ECDM process on the machined zone. This paper comprehensively reviews the effect of change in applied voltage, machining gap and an inter-electrode gap in the ECDM and it also analyses the fabrication of different materials including glass, quartz, ceramics and composites.

A Hardware Vehicle Security and Accident Notification System using the Haar Cascade Algorithm

Low-cost vehicle security and accident notification system is essential in this modern society as vehicle theft and accidents that occur are increasing daily. In this proposed system, hardware for vehicle security is implemented, with authentication, and accident notification. Authentication is achieved by face detection and recognition using an open CV. The defaulter information is forwarded to the authenticated mobile number of the person by whom the vehicle is owned, using the GSM module and a notification email. The face authentication module was developed using the discrete wavelet transform-based Haar cascade algorithm. In addition to the face authentication, accident notifications will be sent to family members of the vehicle owner. Micro electrical mechanical system sensor was utilized to detect accident incidents using the accelerometer concept.

Direct numerical simulation of packed and monolith syngas catalytic combustors for micro electrical mechanical systems

In this work, a catalytic combustor for micro electrical mechanical system for syngas was designed and analysed using Direct Numerical Simulation (DNS) in conjunction with finite rate chemistry. The effect of catalyst (platinum (Pt), palladium (Pd), palladium oxide (PdO), and rhodium (Rh)), bed type (packed with twelve catalyst shapes and four catalyst monolith), shapes (packed: cylinder, hollow cylinder, four cylinder, single cylinder, single cylinder, cross-webb, grooved, pall-ring, hexagonal, berl-saddle, cube, intalox-saddle, and sphere, monolith: triangular, rectangular, hexagonal, and circular), and operating conditions (inlet temperature and velocity, fuel/air ratio, different concentrations CH4-H2-CO) on combustion efficiency and pressure drop were studied using different parameters (combustion efficiency (η), pressure drop, effectiveness factor (Ψ), and fuel conversions (H2 and CH4 conversions)). Analysis under different operating conditions reveals that the designed combustor can operate effectively with syngas of varying compositions with a high combustion efficiency of over 85%. Combustion mainly takes place on the surface of the catalyst without gas phase reaction with pressure drops between 18 Pa and 155 Pa. The intalox saddle shape catalysts resulted in the bed effectiveness factor 0.93.11An ideal reactor effectiveness factor is 1 which 0.5 is equivalent to 100% combustion efficiency and 0.5 is from 0% pressure drop at the combustor outlet. The Damköhler for hydroxyl radicals (OH) over the entire length of the reactor is uniformly distributed and well below 3, suggesting uniform combustion.

Effect of Diametric ratio on Eigen Frequency of Functionally Graded Piezoelectric Round Disc

Abstract: Functionally graded piezoelectric material has very enormous application in the field of engineering and science. It is very useful for smart device like micro electric mechanical system, nano electro mechanical system. In the present work the effect of diametric ratio has been observed for functionally graded piezoelectric circular plate. d15 effect has been utilized for exited shear induced flexural vibration. Plate has been readily polarized and electric effect is applied along the thickness direction.

Pose estimation algorithm for mobile augmented reality based on inertial sensor fusion

<span>Augmented reality (AR) applications have become increasingly ubiquitous as it integrates virtual information such as images, 3D objects, video, and more to the real world, which further enhances the real environment. Many researchers have investigated the augmentation of the 3D object on the digital screen. However, certain loopholes exist in the existing system while estimating the object’s pose, making it inaccurate for mobile augmented reality (MAR) applications. Objects augmented in the current system have much jitter due to frame illumination changes, affecting the accuracy of vision-based pose estimation. This paper proposes to estimate the pose of an object by blending both vision-based techniques and micro electrical mechanical system (MEMS) sensor (gyroscope) to minimize the jitter problem in MAR. The algorithm used for feature detection and description is oriented FAST rotated BRIEF (ORB), whereas to evaluate the homography for pose estimation, <a name="_Hlk100294718"></a>random sample consensus (RANSAC) is used. Furthermore, gyroscope sensor data is incorporated with the vision-based pose estimation. We evaluated the performance of augmenting the 3D object using the techniques, vision-based, and incorporating the sensor data using the video data. After extensive experiments, the validity of the proposed method was superior to the existing vision-based pose estimation algorithms.</span>

Coriolis Vibratory MEMS Gyro Drive Axis Control with Proxy-Based Sliding Mode Controller

MEMS (micro electrical mechanical systems) gyroscopes are used to measure the angular rate in several applications. The performance of a MEMS gyroscope is dependent on more than one factor, such as mechanical imperfections, environmental condition-dependent parameter variations, and mechanical–thermal noises. These factors should be compensated to improve the performance of the MEMS gyroscope. To overcome this compensation problem, a closed-loop control system is one of the solutions. In this paper, a closed-loop control system is implemented. However, other than previously applied methods, a proxy-based sliding mode control approach is proposed, which is a novelty for the control of the MEMS gyroscope drive axis since, to the best of our knowledge, this method has not been applied to gyroscope control problems. Proxy-based sliding mode controllers do not suffer from the chattering phenomenon. Additionally, we do not need an exact system model to implement the control law. In particular, we are investigating, in this paper, the compatibility and performance of a proxy-based sliding mode controller for a closed-loop gyroscope implementation. We show that our proposed method provides robustness against model uncertainties and disturbances and is easy to implement. We also compare the performance of classical sliding mode controllers and proxy-based sliding mode controllers, which demonstrate the evident superiority of the proxy-based controller in our implementation results. Simulation results show that system error and gyroscope total error reduced by 49.52% and 12.03%, respectively, compared to the sliding mode controller. Simulation results are supported with the experimental data, and experimental results clearly demonstrate the superiority of the proxy-based sliding mode controller.

On the use of IMU (inertial measurement unit) sensors in geomorphology

AbstractInertial measurement units (IMUs) are mobile sensors assemblies constructed using a combination of MEMS (micro electrical mechanical systems) accelerometers, gyroscopes and magnetometers. Both the technology and its applications to geomorphic problems are developing rapidly, since they demonstrate the prospect of monitoring individual sediment grains, of various sizes, during transport and at high frequency. This prospect has numerous implications which range from hazard identification and warning to complex theoretical derivations for sediment transport modelling. At the same time, the deployment of IMUs needs to be underpinned by a number of technical considerations regarding the limitations of the technology and the physics of the inertial measurements. IMU measurements should be reported in a manner that allows for clear understanding of the scope of the study, with sufficient detail for repeatability and clear error characterization. At a secondary level, IMU measurements should be linked clearly with the physics of sediment motion. Here the author highlights five technical issues which can lead to the misinterpretation of IMU measurements. His scope is to begin a dialogue towards a collective agreement on a presentation/reporting protocol for IMU measurements in geomorphic studies that will allow for the coherent contextualization of the technology and accelerate its scientific impact within geosciences.

Modeling and simulation of dynamic mechanical systems using electric circuit analogy

Modeling and simulation are prerequisite to analysis and design of engineering systems. Modern engineering systems often are multy disciplinary, i.e., may include blocks from different majors of engineering, such as electrical, mechanical, fluid, etc. Availability of a unified approach for system modeling will make it easy for engineers or researcher from a certain discipline to model the systems from other disciplines. For example, with availability of a unified modeling methodology an electrical engineer will be able to model a system composed of electrical, mechanical and fluid systems. Modeling of complex mechanical systems is not always easy for engineers from other disciplines. On the other hand, it is much easier to establish mathematical model of electric circuits. Furthermore, simulation software is much richer for electric circuits. Therefore, in this paper a methodology is proposed for unifying the modeling of electrical and complex mechanical systems by obtaining electric circuit model of complex mechanic systems. In developing the proposed methodology, analogy between the electrical and mechanical elements have been used as tools. Proposed methodology has been applied to modeling and simulation of a relatively complex mechanical system and benefits accrued from this approach has been discussed. It is further proposed that the approach presented in this paper can be easily extended to modeling of dynamic systems from other engineering disciplines.

Exceptional topology of non-Hermitian systems

The current understanding of the role of topology in non-Hermitian (NH) systems and its far-reaching physical consequences observable in a range of dissipative settings are reviewed. In particular, how the paramount and genuinely NH concept of exceptional degeneracies, at which both eigenvalues and eigenvectors coalesce, leads to phenomena drastically distinct from the familiar Hermitian realm is discussed. An immediate consequence is the ubiquitous occurrence of nodal NH topological phases with concomitant open Fermi-Seifert surfaces, where conventional band-touching points are replaced by the aforementioned exceptional degeneracies. Furthermore, new notions of gapped phases including topological phases in single-band systems are detailed, and the manner in which a given physical context may affect the symmetry-based topological classification is clarified. A unique property of NH systems with relevance beyond the field of topological phases consists of the anomalous relation between bulk and boundary physics, stemming from the striking sensitivity of NH matrices to boundary conditions. Unifying several complementary insights recently reported in this context, a picture of intriguing phenomena such as the NH bulk-boundary correspondence and the NH skin effect is put together. Finally, applications of NH topology in both classical systems including optical setups with gain and loss, electric circuits,s and mechanical systems and genuine quantum systems such as electronic transport settings at material junctions and dissipative cold-atom setups are reviewed.

Acoustic Emission and Fractal Precursory Characteristics of Coals with Different Bursting Liabilities in Loading Failure Process

Aimed at investigating the differentiation of acoustic emission (AE) signals and fractal precursory characteristics between strong, weak, and no bursting liability coals under uniaxial compression, as well as improving the accuracy of rockburst monitoring and early warning by AE techniques, we experimentally studied the evolution law and differences of AE ring count rate, energy rate, and correlation dimension between different loaded bursting liability coals by the YAW4306 electric mechanical test system and CTA‐1 AE monitor. Our experimental results indicated that the AE count and energy of coal samples with different bursting liabilities showed a similar evolution law of “sharp increase‐calm‐sharp increase” before their main rupture. The active points of AE signals emitted from coal with strong, weak, and no bursting liability appeared at about 85∼90%, 75∼78%, and 51∼55% of the peak stress, respectively. The stronger the bursting liability of coal, the shorter the duration of main rupture and postpeak failure stage, and the greater the AE energy rate in the main rupture. The AE counts of different coals had obvious fractal characteristics, and the AE correlation dimension values of strong and weak bursting liability coal samples presented the phenomenon of “fluctuating rise to a peak value‐sharp drop‐continuous decrease,” which can be used as a precursory information of coal failure.

Design and fabrication of microcontroller-based dual axis light-sensitive rotating solar panel

ABSTRACT This study predominantly focuses on the design, fabrication and performance of a dual-axis sun-tracking solar system. The whole construction of the dual axis rotating solar panel is divided into two sub-division, i.e. electrical system design and mechanical system design. The components of electrical and mechanical design system contribute individually for the efficient working of the dual axis light-sensitive rotating solar system and add a combined result in the system. Solar energy is immense, open in the environment, sparkling from contamination and renewable basis of electricity. The dual axis light-sensitive solar tracking system is an outcome of this mission. In this present study the aforesaid system is built and tested based on both the solar map and light-sensor-based continuous tracking mechanism. The power gain and system power consumption are compared with a static solar tracking system. It is found that power gain of this system has attested to be more proficient and beneficial than its fixed equivalents. The consequence exposed that the solar system with dual-axis tracking is further effective paralleled to that fixed solar system.

Real time localization solution for land vehicle application using low-cost integrated sensors with GPS

The technique proposed in this research demonstrates a real time nonlinear data fusion solution based on extremely low-cost and grade inertial sensors for land vehicle navigation. Here, the utilized nonlinear multi-sensor data fusion (MSDF) is based on the combination between extremely low-cost micro electrical mechanical systems (MEMS) inertial, heading, pressure, and speed sensors in addition to satellite-based navigation system. The integrated navigation system fuses position and velocity states from the Global Positioning System (GPS), the velocity measurements from an odometer, heading angle observation from a magnetometer and navigation states from an inertial navigation system (INS). The implemented system performance is assessed through the post-processing of collected raw measurements and real time experimental work. The system that runs the real-time experiments is established on three connected platforms, two of them are based on a 32-bit ARMTM core and the third one is based 16-bit AVR ATMEL microcontroller. This microcontroller is connected to an on-board diagnostics (OBD) shield to collect the vehicle speed measurements. The raw data obtained from the integrated sensors is saved and post processed in MATLAB®. In normal conditions, the estimated position errors are reduced through the usage of INS/GPS integration with heading observation angle from a magnetometer. In GPS-denied environments, the integrated system uses the observations from INS, magnetometer in addition to the velocity from odometer to ensure a continuous and accurate navigation solution. A complementary filter (CF) is implemented to estimate and improve the pitch and roll angles calculations. In addition to that, an unscented Kalman filter (UKF) is used cascaded with the designed CF to complete the designed sensors fusion algorithm. Experimental results show that the designed MSDF can achieve a good level of accuracy and a continuous localization solution of a land vehicle in different GPS availability cases and can be implemented on the available in the market processors to be run in real time.

Design and fabrication of high productive barbecue machine

Conventional methods to use a metal cavity having charcoal assisted with skewers in getting the final barbecue encounter a lot of limitations such as time, lower productivity, single temperature heating, worker fatigue, controlling of heat and time, energy consumption, importability, unhygienic food preparation (road-side open barbecuing) and cost-effectiveness etc. The proposed research considers the design and fabrication of barbecue machine fueled with gas and actuated by electrical cum mechanical systems. This electromechanical semi-automatic barbecue machine overcomes the stated limitations. It will be an important tool used for household as well as commercial use. This machine capacity is to barbecue an average of 4.5 kg of meat at a time. The machine is divided into three chambers. In first chamber barbecue is kept on lower temperature for high time. Once it completes its first stage motor attached with chain drive mechanism is activated and it brings the food to second chamber. In the second chamber, it takes lower time on high temperature and when it finishes it is conveyed to first chamber for un-feeding. The aim of this research is also to commercialize the product in the market targeting small scale industries and people involved in road side barbecue production, restaurants and other organizations.

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Meet the First Authors

Intelligent Rate-Dependent Hysteresis Control Compensator Design With Bouc-Wen Model Based on RMSO for Piezoelectric Actuator

Piezoelectric actuators (PAs) require high precision positioning for the applications of micro electrical mechanical systems, but it exhibits hysteresis nonlinearity which deteriorates positioning accuracy if no proper compensation is given. Hysteresis nonlinear modeling of PAs is a prime choice for hysteresis compensation. This paper proposes a novel intelligent positioning control algorithm based on Bouc-Wen (BW) model for the compensation of a bi-morph type piezoelectric actuator (PA) suffering rate-dependent hysteresis. A region based mixed-species swarm optimization (RMSO) algorithm is proposed for BW modeling to capture the dynamic nonlinearity of a piezoelectric actuator which exhibits rate-dependent hysteresis. Results of numerical simulations have been disclosed to illustrate the performance enhancement of RMSO over classical algorithm while they are applied to the parameter fitting problem of BW model for experimentally acquired datasets. An model based adaptive Fuzzy neural network (Fuzzy-NN) controller of PA is utilized to compensate the hysteresis for the positioning tracking control. Experimental results also illustrate the good performance of the proposed RMSO-BW based control scheme for the hysteresis compensation control of the PA.

Improved Position Estimation of Real Time Integrated Low-Cost Navigation System Using Unscented Kalman Filter

Low cost Micro Electrical Mechanical Systems (MEMS) inertial sensors have nominated their use in domains such as navigation systems but these sensors are noisy and characterized by their measurements drift and large errors. In this work, an integrated navigation system is implemented and its performance is evaluated through experimental work in both post processing and real time domains. The real time processing is built on multi-platform 32-bit ARM core ATMEL microcontroller while at the same time raw sensors measurements are saved for post processing under MATLAB. North and East position errors measurements were used in this work to evaluate position improvement calculated using MEMS inertial sensors integrated with position and velocity from Global Positioning System (GPS) receiver readings at slow rates. For such evaluation, the calibrated measurements from gyroscopes and accelerometers are fed to a mechanization process to build an inertial navigation system (INS). The INS drifting navigation solution is fused with a GPS measurement through Unscented Kalman Filter (UKF). UKF does not require linearization of the system model such as the status of the commonly used Extended Kalman Filter (EKF). The results of the experimental work show that the implemented low cost integrated navigation system based on UKF can achieve a level of accuracy superior than other (EKF) based expensive systems.

Current loading of electrical model of electrical mechanical system of water supply network

The nature of the electromagnetic process in the scheme of the electrical model of the electromechanical system of a water supply network with a pump D 2000-100 is investigated. In this case, the main attention is focused on the patterns of change in the load current of the model, which simulates the movement of fluid in the spiral outlet of the pump, depending on the design features of its output part. The parameters of the electric model elements, based on the method developed by the authors for creating an electric model of a centrifugal pump, correspond to the nominal operating mode of the system and are used in the numerical calculation. The part of the load circuit of the electric model, which models the spiral outlet of the pump, consists of series-connected resistance R1 and inductance L1, to which the capacitive element C is connected in parallel. Studies have shown that the nature of transients can be aperiodic or oscillatory, depending on the ratio of the parameters of these elements. The oscillatory nature of the process indicates the possibility of vibrations in the electromechanical system. However, it was shown that, depending on the ratio between the frequency of the vibration source and the natural frequency of the output part of the electromechanical system, the intensity of the manifestation of vibration is different. Therefore, the main conclusion of the publication is that the use of electrical methods for modeling the working processes of electromechanical systems can be used to eliminate undesirable equipment operation modes in order to increase the energy efficiency of the water supply process.

Devising a procedure for the synthesis of electromechanical systems with cascade-enabled fractional-order controllers and their study

An approach to the synthesis of automatic control circuits has been proposed, based on a fractional characteristic polynomial, which makes it possible to ensure the desired quality of a transition process under condition for implementing a certain structure of the fractional controller, which depends on the transfer function of a control object. The use of fractional desirable forms extends the range of possible settings of fractional-order controllers in the synthesis of circuits for electrical-mechanical systems, ensures better quality of transients compared to the full-order controllers, and thereby improves the efficiency of synthesized systems. Based on the obtained results of research, it becomes possible to recommend, in order to adjust the circuits for electromechanical systems, using the proposed fractional desirable forms that could meet the desired requirements to the systems of control over electromechanical systems. Construction of electromechanical systems on the principle of control with sequential correction has a significant advantage over other systems, owing to the simplicity of setting each contour, as well as a possibility to implement control coordinate constraints. A procedure for the structural-parametric synthesis of fractional-order controllers has been devised, on condition of their cascading switching in multi-circuit electromechanical systems; the synthesis algorithm of fractional-order controllers for appropriate control circuits has been given. We have synthesized an electromechanical system with cascade switching of controllers by applying the improved method of the generalized characteristic polynomial to choose the structure and parameters of fractional-order controllers and applying the desired form of fractional order. A two-circuit system of subordinate regulation has been considered as an example, in which a control object is the electric drive "thyristor transducer (converter) – engine (motor)". The influence of the synthesized fractional-order controllers on dynamic properties of the electromechanical system "thyristor transducer – engine" has been examined. Our study has shown a possibility to implement the cascading activated controllers for the electromechanical systems where the contours with the transfer full- and fractional-order functions are combined, as well as for systems with fractional-order contours only

GPS/DVL/MEMS‐INS smartphone sensors integrated method to enhance USV navigation system based on adaptive DSFCF

Although the inertial navigation system (INS) can provide a continuous navigation solution for most of unmanned surface vehicles (USVs), its reliability decreases over time due to the accelerometer and gyroscope drifts. The authors’ study introduces a novel method based on integrated micro electric mechanical system (MEMS)-INS smartphone sensors with global positioning system (GPS) and Doppler velocity log (DVL). Since the GPS and DVL are used as reference systems to correct MEMS-INS errors, their accuracies are decreased due to the bad weather and the noise of DVL, which effect on the efficiency of a whole navigation system. To resolve this problem, the adaptive data sharing factor combined filter (DSFCF) is used as integrated method. According to adaptive DSFCF integrated method, the reference system which has the beast accuracy is used to correct the USV navigation errors, and at the same time the least accuracy system will be detected and avoided. The proposed GPS/DVL/MEMS-INS using adaptive DSFCF integrated method was tested on a surface reference trajectory in Mukalla city-Yemen. The estimated results by this proposed method could provide a reliable navigation solution and give the least error compared by the GPS/DVL/MEMS-INS Centralised Kalman filter and the GPS/DVL/MEMS-INS constant DSFCF integrated methods.