Electromechanical Design Research Articles

Integration of electrotaxis and durotaxis in cancer cells: Subtle nonlinear responses to electromechanical coupling cues

Cells in living organisms live in multiphysics-coupled environments. There is growing evidence indicating that both exogenous electric field (EEF) and extracellular stiffness gradient (ESG) can regulate directional movement of cells, which are known as electrotaxis and durotaxis, respectively. How single cells respond to the ubiquitous electromechanical coupling cues, however, remains mysterious. Using microfluidic chip-based methodology and finite element-based electromechanical coupling design strategies, we develope an electromechanical coupling microchip system, enabling us to quantitatively investigate polarization and directional migration governed by EEF and ESG at the single cell level. It is revealed that both of electrotaxis and durotaxis nonlinearly depend on the physiological EEF and ESG, respectively. Specific combinations of EEF and ESG can subtly modify the polarization states of single cells and thus induce hyperpolarization and depolarization. Cells can integrate electrotaxis and durotaxis in response to multi-cue microenvironments via subtle mechanisms involving cooperation and competition during cellular electrosensing and mechanosensing. The work offers a platform for quantifying migration and polarization of cells driven by electromechanical cues, which is essential not only for elucidating physiological and pathological processes like embryo development, and invasion and metastasis of cancer cells, but for manipulating cell behaviors in a controllable and programmable fashion.

Electromechanical Design of Synchronous Power Controller in Grid Integration of Renewable Power Converters to Support Dynamic Stability

Nowadays, modern power converters installed in renewable power plants can provide flexible electromechanical characteristics that rely on the developed control technologies such as Synchronous Power Controller (SPC). Since high renewable penetrated power grids result in a low-inertia system, this electromechanical characteristic provides support to the dynamic stability of active power and frequency in the power generation area. This goal can be achieved through the proper tuning of virtual electromechanical parameters that are embedded in the control layers of power converters. In this paper, a novel mathematical pattern and strategy have been proposed to adjust dynamic parameters in Renewable Static Synchronous Generators controlled by SPC (RSSG-SPC). A detailed dynamic modeling was obtained for a feasible design of virtual damping coefficient and virtual moment of inertia in the electrometrical control layer of RSSG-SPC’s power converters. Mathematical solutions, modal analysis outcomes, time-domain simulation results, and real-time validations of the test in IEEE-14B benchmark confirm that the proposed method is an effective procedure for the dynamic design of RSSG-SPC to provide these dynamic stability supports in grid connection.

Switched Reluctance Motors and Drive Systems for Electric Vehicle Powertrains: State of the Art Analysis and Future Trends

This paper presents a detailed literature review on switched reluctance motor (SRM) and drive systems in electric vehicle (EV) powertrains. SRMs have received increasing attention for EV applications owing to their reliable structure, fault tolerance ability and magnet free design. The main drawbacks of the SRM are torque ripple, low power density, low power factor and small extended speed range. Recent research shows that multi-stack conventional switched reluctance motors (MSCSRM) and multi-stack switched reluctance motors with a segmental rotor (MSSRM-SR) are promising alternative solutions to reduce torque ripples, increase torque density and increase power factor. Different winding configurations such as single-layer concentrated winding (SLC), single layer mutually coupled winding (SLMC), double layer concentrated winding (DLC), double layer mutually coupled winding (DLMC) and fully-pitched winding (FP) are introduced in the literature in recent years to increase average torque and to decrease torque ripples. This research analyzes winding methods and structure of the SRMs, including conventional and segmental rotors. They have been compared and assessed in detail evaluation of torque ripple reduction, torque/power density increase, noise/vibration characteristics and mechanical structure. In addition, various drive systems are fully addressed for the SRMs, including conventional drives, soft-switching drives, drives with standard inverters and drives with an integrated battery charger. In this paper, the SRM control methods are also reviewed and classified. These control methods include strategies of torque ripple reduction, fault-diagnosis, fault-tolerance techniques and sensorless control. The key contributions of this paper provide a useful basis for detailed analysis of modeling and electromechanical design, drive systems, and control techniques of the SRMs for EV applications.

A Note on the Electromechanical Design of a Robotic Hummingbird

This paper analyzes the lift-production system in hovering of the flapping wing robot COLIBRI of the size of a hummingbird. The paper first examines the flapping wing mechanism for which a new gear transmission is proposed to reduce the friction and facilitate the assembly. Next, a sensitivity analysis is performed on the wing size. Then, the paper discusses several options for the gearbox, various DC motors and two battery configurations (a single battery or two batteries in series) to minimize the heat generation and increase the flight time. The configuration involving two batteries has been found more effective. The flight time is predicted using Shepherd’s discharge model and it is confirmed by an experiment. The robot sustains an endurance of nearly 5 min to produce a lift force equal to the weight of the robot.

Comparative Evaluation of AC and DC Power Distribution Systems for Underwater Vehicles Based on Multiobjective Optimization Techniques

This paper presents a multiobjective optimization technique for the submarine cables of high-power remotely operated vehicles (ROVs). A detailed design flowchart with integrated electrical and mechanical designs of the ROV submarine cables is provided to quantitatively compare AC and DC-based power distribution systems and identify the optimal design from multiple standpoints, prioritizing electrical loss and cable weight. The electromechanical cable design optimization plays a vital role in the ROV industry and in all those applications where the power distribution system is employed vertically from the support platform/vessel. The entire procedure is exemplified by carrying out a particular case study; for an ROV power hub with rated power of 5 MW and operational depth of 6000 m, the DC submarine cable design with distribution voltage of 33 kV results in an electrical loss reduction of 54.3% compared to the AC submarine cable design with distribution voltage of 22 kV at similar cable weights of 63 ton. Additionally, the proposed method can be widely applied to any type of AC-DC comparison to achieve the optimal ROV submarine cable design with a considerably short process time in comparison to the approaches with finite element analysis.

Continuous and Time-Domain Coherent Signal Conversion between Optical and Microwave Frequencies

Converting seamlessly between optical and microwave frequencies would enable ultralow-loss long-distance communication of both classical and quantum signals, and could enable a quantum telecommunication repeater. High conversion rates with low loss are needed for any practical technology. The authors present a significant step toward both of those goals: an integrated electromechanical and optomechanical design that yields significantly lower loss with megahertz conversion rates, which is promising for future bidirectional quantum communication. Their design includes a number of innovations for generating and transmitting the rf acoustic signals that are key to device operation.

3D-Printed Strain Sensors: Electro-Mechanical Simulation and Design Analysis Using Nonlinear Material Model and Experimental Investigation

This work is driven by the continuous improvement in additive manufacturing and the growing interest in developing flexible strain sensors with complex designs and structures. Characterization and analysis require not only understanding the mechanical behavior of the sensor but also the electrical behavior and the coupled electromechanical behavior. Traditionally, this coupled electromechanical behavior is determined using simplified approaches to establish a relationship between the electrical domain and mechanical domain. This work presents an experimental and numerical platform to characterize strain sensors and serves as a tool for design guidelines for these sensors. A nonlinear finite element COMSOL model is developed and validated against experiment. At 38% strain level the sensitivity is increased by 7% when the thickness,t, of the sensor decreased from t = 1.4 mm to t = 0.6 mm. A sensor with triangular embedded channels exhibits improved performance compared to square, hexagonal, and octagonal cross-sectional shapes. Three common channel patterns are examined including spiral, vertical serpentine, and horizontal serpentine patterns. Three commonly used materials for fabricating strain sensors are investigated including PDMS, EcoFlex, and NinjaFlex. At 35% strain level, a sensor with NinjaFlex substrate exhibits, approximately, 6% improvement in sensitivity, compared to a sensor with EcoFlex substrate.

Conceptual Scheme Decision Model for Mechatronic Products Driven by Risk of Function Failure Propagation

Reliability is a major performance index in the electromechanical product conceptual design decision process. As the function is the purpose of product design, the risk of scheme design is easy to be caused when there is a failure (i.e., function failure). However, existing reliability analysis models focus on the failure analysis of functions but ignore the quantitative risk assessment of conceptual schemes when function failures occur. In addition, design information with subjectivity and fuzziness is difficult to introduce the risk index into the early design stage for comprehensive decisions. To fill this gap, this paper proposes a conceptual scheme decision model for mechatronic products driven by the risk of function failure propagation. Firstly, the function structure model is used to construct the function fault propagation model, so as to obtain the influence degree of the subfunction failure. Secondly, the principle solution weight is calculated when the function failure is propagated, and the influence degree of the failure mode is integrated to obtain the severity of the failure mode on the product system. Thirdly, the risk value of failure mode is calculated by multiplying the severity and failure probability of failure mode, and the risk value of the scheme is obtained based on the influence relationship between failure modes. Finally, the VIKOR (Višekriterijumska Optimizacija i kompromisno Rešenje) method is used to make the optimal decision for the conceptual scheme, and then take the cutting speed regulating device scheme of shearer as an example to verify the effectiveness and feasibility of the proposed decision model.

Deepening of Integrated pipeline - based BIM

The traditional electromechanical design using two-dimensional drawings conveys information that is relatively abstract, which means simple profiles and elevation drawings can’t reflect the three-dimensional effect of the pipeline. And that will cause some problems such as collisions during the construction process, disordered pipeline layout, and unreasonable space utilization. As a three-dimensional design technology, BIM can solve the above problems well. This paper describes the deepening and construction methods of pipe comprehensive based on BIM technology in detail. On the basis of refined modeling, combined with on-site construction experience and the comprehensive layout specifications of various professional pipelines, NAVISWORKS is used for collision detection, which is carried out with the designer and the builder, and the optimization of the original design drawings of the project. The deepened model can be used directly to guide on-site construction, that can reflect the important application value of BIM technology in electromechanical engineering.

Some aspects of the electromechanical design of high-speed microturbines for power generation

Some aspects of the electromechanical design of high-speed microturbines for power generation

The Cost-Sorted Distance Method for Identifying Minima Within Firefly Optimization Results: Application to Engineering Design

Abstract This paper provides a detailed description of the cost-sorted distance (CSD) method for visually and computationally identifying objective function minima within clustered population-based optimization results. CSD requires sorting the design vector population by cost and computing Euclidean distances between each pair of designs. It may be applied in conjunction with any population-based optimization method (e.g., particle swarm, genetic algorithm, simulated annealing, ant colony, firefly), but it is naturally compatible with the firefly algorithm (FA) because FA also requires the distances between each pair of design vectors and benefits from cost-sorting the population (the computational work required for CSD is a byproduct of FA). A modified FA is presented that uses CSD to more thoroughly search near potential minima and a systematic method for tuning the algorithm to reliably identify multiple minima is documented. The tuned algorithm's efficacy is demonstrated using a class of benchmark problems and a “real world” electromechanical design problem, where the identification of attractive design alternatives can be challenging.

Bidomain ferroelectric crystals: properties and prospects of application

Lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) are among the most important and most widely used materials of coherent and nonlinear optics, as well as acoustics. High degree of uniformity and reproducibility has become the foundation of technology for manufacturing high-quality crystals, absorbed by many suppliers around the world. However, the above areas do not limit the use of LiNbO3and LiTaO3due to their unique piezoelectric and ferroelectric properties. One promising application of crystals is the design of electromechanical transducers for precision sensors and actuators. In this respect, the high thermal stability of the piezoelectric and mechanical properties, the lack of hysteresis and creep make it possible to create electromechanical converters with wide operating temperature range, that is beyond the capability of commonly used ferroelectric ceramics. The main advantage of LiNbO3and LiTaO3over other single-crystal piezoelectrics is ferroelectric domain structure regulation toward targeted impact on the device characteristics. One of the most striking examples of electromechanical transducer design through domain engineering is the formation of a so-called bidomain ferroelectric structure in crystal. It represents a single-crystalline plate with two macrodomains with opposite directions of spontaneous polarization vectors separated by a charged domain wall. High switching fields make inversion domains stable at temperatures up to 1000 °C. This review summarizes the main achievements in the formation of bidomain structure and near surface inversion domains in LiNbO3and LiTaO3crystals. We present the domain structure virtualization methods in crystals and non-destructive methods for controlling the domain boundary position. The report contains a comparative analysis of the methods for forming inversion domains in crystals, and the patterns and technological control methods of the domain structure are discussed. The basic physical models have been proposed in the literature to explain the effect of the inversion domains formation. In the present paper we outline what one sees as strengths and weaknesses of these models. The strategies of crystallographic cut selection to create devices based on bidomain crystals are briefly discussed. We provide examples of the implementation of devices based on bidomain crystals such as actuators, sensors, acoustic transducers, and waste energy collection systems.

Dynamic Electromechanical Model and Position Controller Design of a New High-Precision Self-Bearing Linear Actuator

Direct drive tubular linear actuators (TLAs) may be used in various applications that require fast movements and high-precision positioning, e.g., pick-and-place robots. This article presents the analysis, dynamic electromechanical model derivation, controller design, and system operation of a TLA with integrated magnetic bearings (MBs). Furthermore, the actuator operation is verified with extensive measurements on the prototype, which include axial position step response, standard deviation of the steady-state positions and mover tilting control. Compared with any conventional TLA, which may perform only linear motion, the mover tilting control is possible due to integrated MBs. This gives the new actuator a great advantage in high-precision positioning systems, since any thermal expansions of the parallel kinematics may be compensated.

İç Sular İçin Otonom Suüstü Araç Tasarımı ve Uygulaması

This paper considers the design and implementation of a low-cost and modular autonomous surface robot for inland water. The design process consists of three stages: Mechanical and electro-mechanical design, electrical and electronic design and software design. The mechanical design is based on a two-hull construction because of its low risk of capsizing in rough water. Off-the-shelf hulls and electric trolling motor are preferred to reduce the cost. The robot is steered by a rudder controlled by a servo motor. A Robot Operating System based software running on an on-board computer is developed to achieve autonomy. The robot’s status is monitored using the ground station software. The developed system was tested through a series of field experiments. The system is also compared with the existing designs. The robot’s available deck space and modular software architecture enable users to easily integrate various sensors and mechanical parts for a wide range of applications such as environmental monitoring, surveillance and patrolling.

Design, Prototyping and Testing of a Rotating Electrical Machine With Linear Geometry for Shipboard Applications

Conventional rotating electrical machines are characterized by stator and rotor structures featuring a cylindrical geometry around the shaft rotational axis. Although advantageous for mechanical reasons, the cylindrical geometry results in overall machine shapes and dimensions that may be unsuitable for installation. This particularly occurs in shipboard applications, where electric motors and generators are subject to stringent room constraints and need to be fit in unusually shaped compartments. This paper presents the development and test of a dual-shaft rotating permanent-magnet electric machine prototype having a linear structure that facilitates its onboard use for such applications as electric propulsion and rudder actuation. In fact, the proposed machine topology has overall dimensions which can be adjusted to fit the space available for installation. The operating concept and the detailed electromechanical design of the machine are first described. Then the manufacturing and factory test of the prototype under inverter supply are illustrated. Finally, the validation of the prototype as a boat propulsion variable-speed inverter-fed motor is presented. It is proved that, despite of its highly non-conventional electromechanical design, the machine can be effectively fed from a general-purpose inverter for permanent magnet motors.

Study on Model-Based System Engineering in Satellite Layout

For satellite layout, it is necessary to collate manually in order to obtain accurate product technical requirements information. It is difficult to track the technical status information. It is proposed that the application of model-based system engineering (MBSE) in the cooperative development of multi-disciplinary and multisectoral satellite layout was an effective way to solve these problems. Based on the four typical processes of layout design, this paper studied the requirements to occupancy design, electromechanical joint design, integration of Attitude and Orbit Control System (AOCS) equipment layout, definition and display of equipment expansion, and give the verification design of star sensor layout. The results show that this method is beneficial to the collaboration of all departments, and improve the design ability.

Electromagnetic torque and strength analysis of combination rotor in high speed PMSM

For a high-speed permanent magnet synchronous motor supported by air foil bearings, analyzing the influence of the electromagnetic torque on the strength of the combination rotor was necessary. In this study, the electromagnetic torque was obtained using the analytical calculation and the finite element simulation. The contact interface stress analytical equation affected by the electromagnetic torque was elaborated. A three-dimensional finite element model simulating the combination rotor was constructed, and the stress calculations were performed. The strength of the combination rotor met the design requirement. It properly reflected the characteristics of the electromechanical analysis in the combination rotor. The operation experiments were realized to verify the electromagnetic performance and the strength of the combination rotor. The simulation and experimental results were significant for the electromechanical design and analysis of the combination rotor.

Smart concept design based on recessive inheritance in complex electromechanical system

Due to the substantial increase in users demand, the scale of complex electromechanical systems is rapidly enlarging when systems are rapidly merging, and the complexity of the system has been greatly increased. Even if the original system is running well, singular phenomena often occurs in the process of complex electromechanical systems integration, which leads to the failure of the functional requirements of the new generation of products. In the face of the singular phenomena of complex electromechanical systems, traditional solutions focus more on solving the problems existing in the current complex electromechanical systems, and do not deeply study the root causes of the singular phenomena in the design process of complex electromechanical systems. The singular phenomena of system has high concealment and is not easy to be detected at the design stage, and similar singular phenomena will appear repeatedly in multiple generations of the same product. These characteristics are very similar to the characteristics of recessive inheritance of biological systems. Therefore, the paper will compare complex electromechanical systems with biological systems, and propose a recessive inheritance mechanism of complex electromechanical systems that can be used in smart concept design by introducing the recessive inheritance mechanism of biological system into the complex electromechanical system design process. First, use function trimming to build a functional gene for new complex electromechanical systems. Second, combine the Length and Time dimension chart (L-T chart) and Computer Aided Innovation (CAI) to find the recessive parameters that may exist in the design of the new generation system and analyze the possible coupling phenomena between the recessive parameters. Then, using the Invention Problem Solving Theory (TRIZ) tools to solve the coupling relationship between recessive parameters to reduce the possibility of singular phenomena in the new generation system, forming a new generation of complex electromechanical system smart concept design theory framework. Finally, for the design example of the new generation of energy-saving surface platform, the proposed method is used to determine the design scheme, establish a 3D model and verify the feasibility and scientificity of the theory by Ansys analysis.

Comparative Research of Electromechanical Design Schemes for Highway Tunnels between China and Eastern Europe

This study aims to strengthen the understanding of the electrical and mechanical (E & M) design plans of highway tunnels in Eastern Europe and to create a foundation for Chinese enterprises to open up the market for tunnel E & M installation projects in Eastern Europe. The Bar-Boljare Highway in the Republic of Montenegro is taken as an example to conduct a comparative research on the E & M designs of highway tunnels in China and Eastern Europe. On the basis of tunnel electrical and mechanical facilities covering ventilation, lighting, fire protection, monitoring, communication, and power supply and distribution, the comprehensive comparison focuses on design concept, design scale, design specifications, design parameters, design plan, equipment selection, and other aspects. The research method involves comprehensively comparing and studying the E & M installation work standards in China and East Europe and the Bar-Boljare Highway Project in Montenegro and similar projects in China. The expected conclusion of this study is that the tunnel E & M design concepts in China are mostly similar to those in Eastern Europe, with few differences. The selection of tunnel systems, such as lighting, ventilation, fire protection, monitoring, and other types of E & M facilities, and the layout of evacuation, indication, and other types of safety facility signs predicate the importance attached to tunnels. The E & M designs of tunnels in Eastern Europe are relatively large in scale and have all mechanical types, and the tunnels with a length exceeding 400 m are equipped with a relatively complete set of systems; in China, the same could be said of only category B tunnels or above. Design standards in China are systematic, whereas no unified design system exists in Eastern Europe, with a conspicuous difference noticed among miscellaneous standards. The valuation of design parameters in Eastern Europe is similar to that in China, but the valuation of luminance outside tunnels is more scientific than that in China. The valuation of fire disaster release amount of the ventilation system is also larger in the former. The tunnel fire rescue evacuation and escape-related design considerations in Eastern Europe are, to some extent, redundant but more scientific and humane, whereas they are more economical and reasonable in China. Eastern European tunnels are equipped with domestic undermanned portal railings, and radio and traffic broadcasts. Great differences in design norms exist between the tunnels in Eastern Europe and China. The parameters of fire-related equipment in Eastern Europe are more demanding than those in China, whereas the parameters for some equipment are highly conservative.

A molecular perspective to analytical modeling that reveals new instabilities in dielectric elastomer transducers

We use a four-parameter material model for polymers - the Edward–Vilgis (EV) model, which models polymeric crosslinks, sliplinks, slippage and inextensibility to analyze dielectric elastomers (DEs). The EV model allows us to investigate the DE response from a molecular perspective, revealing new instabilities in DEs, primarily due to sliplinks. We compare the EV model with the Gent model – a crosslink-only model commonly used in the field of DE, on its ability to fit the non-linear stress–strain response of an acrylic elastomer (VHB 4905), which contains a significant amount of entanglements. We found that the EV model provided an excellent fit to the strain softening phenomenon at small to modest strains, which is missed by the Gent model. Slippage of sliplinks at these regions of strain produces slip resistance that contributed to enhance the resistance to applied forces. Subsequent slip relaxation due to the uncoiling of entanglements will lead to significant strain softening, giving the DE a higher susceptibility to mechanically and electro-mechanically-induced instabilities. From our analyses, we produced mechanical stability phase plots and electromechanical stability design plots, for elastomers of different sliplink-to-crosslink compositions. Such plots may serve as guides to develop dielectric elastomers with desired material properties and performances, and tailor to specific applications.