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RFID (Radio Frequency Identification), which transmits control data through electronic tags in a non-contact manner, provides a new approach for efficient and low-cost remote control of oil downhole tools. However, the interference of harsh downhole environments and the high-speed movement of tags seriously affect the performance of the current downhole reader. To effectively address this issue, in this study, a novel downhole RFID reader is presented. By introducing the half-duplex communication protocol to replace the current full-duplex communication protocol in the hardware circuits of the reader, its tag recognition ability can be improved. Then, the corresponding hardware circuits and software programs are designed. Furthermore, a sparse solenoid antenna is adopted to replace the traditional tightly wound solenoid antenna, which can provide a longer reading area range to cope with the high-moving tag, and its total length and spacing parameters between adjacent coils are designed in detail. The test results show that the proposed RFID reader based on a half-duplex communication protocol can communicate with tags normally, and its sparse solenoid antenna provides significantly more tag reading times than traditional tightly wound solenoid antennas under the same antenna inductance. [ABSTRACT FROM AUTHOR]

Traditional wet plug charging for autonomous underwater vehicles (AUVs) limits its application. Inductive power transfer (IPT) is an effective solution to this problem. This paper proposes an arc‐shaped magnetic coupler incorporated with solenoid coils to achieve a stable and efficient output against rotational misalignment for charging AUV. The novel magnetic coupler consists of two solenoid coils and an arc‐shaped coil with a reverse winding, guaranteeing a relatively constant total mutual inductance and decoupling from each other. This magnetic coupler has the characteristics of a compact structure, an ultra‐wide coupling range, and a relatively stable equivalent mutual inductance. The experimental IPT prototype can deliver 1.29 kW with a dc–dc efficiency of 93% under the fully aligned case and 1.2 kW with a dc–dc efficiency of 91% under the misaligned case. [ABSTRACT FROM AUTHOR]

Inductively coupled power transfer (ICPT) technology is widely used in wireless charging systems because of its safety, convenience, and reliability. However, the loosely coupled transformer, the most significant part of an ICPT system, has misalignment conditions in practical applications, which have a negative effect on the efficiency of the ICPT system. This paper proposes a new loosely coupled transformer structure, where the primary side is composed of two hybrid winding D coils and a solenoid coil, and the secondary side consists of a D coil and a solenoid coil, which is referred to as a "double-D solenoid coil–D solenoid coil" (DDS–DS). The hybrid winding D coils, which are composed of multiple layers of windings, can construct a uniform magnetic field at the operational air gap. The S coil is added to the primary and secondary sides of the transformer to build a mutually perpendicular energy channel with the D coils, which compensates the coupling valley without introducing cross-coupling. Therefore, the DDS–DS structure can construct a wide uniform magnetic field and effectively improve the anti-offset capability of the system. Finally, an experimental prototype is established, and the effective charging width reaches 78% of the transmitting coil's width with a 50 mm operational air gap, which verifies that the structure has good anti-offset capability. [ABSTRACT FROM AUTHOR]

For enhancing the static magnetic field and reducing the size of torsional guided wave magnetostrictive patch transducer (MPT) with permanent magnets, a MPT with Halbach arrays is proposed. The structural parameters design of the MPT can be guided by finite element simulation. It is found that increasing the central angle of the radially magnetised magnets can increase the strength of the static magnetic field, and it can be adjusted through designing the radial size and lift-off distance of the magnets. The Halbach magnet arrays composed of circumferentially magnetised magnets with a circumferential size of 6 mm and radially magnetised magnets with a circumferential size of 4 mm are selected to experimentally compare with the alternating magnetised magnet arrays composed of magnets with a circumferential size of 10 mm. The results show that the static magnetic field strength can be increased by 54.7% using Halbach magnet arrays. The proposed MPT composed of the Halbach magnet arrays and a linear solenoid array can excite and receive T(0,1) guided wave. Compared with the alternating magnetised magnet array MPT, the guided wave signal amplitude is increased by about 70% generated and received by the MPT with the Halbach magnet arrays. [ABSTRACT FROM AUTHOR]

We extend Nekrashevych's KK-duality for C^*-algebras of regular, recurrent, contracting self-similar group actions to regular, contracting self-similar groupoid actions on a graph, removing the recurrence condition entirely and generalising from a finite alphabet to a finite graph. More precisely, given a regular and contracting self-similar groupoid (G,E) acting faithfully on a finite directed graph E, we associate two C^*-algebras, \mathcal {O}(G,E) and \widehat {\mathcal {O}}(G,E), to it and prove that they are strongly Morita equivalent to the stable and unstable Ruelle C*-algebras of a Smale space arising from a Wieler solenoid of the self-similar limit space. That these algebras are Spanier-Whitehead dual in KK-theory follows from the general result for Ruelle algebras of irreducible Smale spaces proved by Kaminker, Putnam, and the last author. [ABSTRACT FROM AUTHOR]

The maximum radial size of the conventional three-bit four-way electromagnetic cartridge valve is greater than the largest containable size of the fluid control valve used for downhole robots. This paper proposes two kinds of solutions to reduce the radial dimension of the three-bit four-way electromagnetic insertion valve: one is to reduce the radial arrangement of the coil and increase the axial arrangement of the coil, and the other is to reduce the diameter of the moving iron core to reduce the winding radius of the coil. Using the theoretical model established in the following text, a simulation experiment was conducted. The results show that the movement of the valve spool is basically completed within 30 ms. Then, a matching experiment on the electromagnetic insertion valve was designed and conducted. The experimental results show that the opening time of the solenoid valve on the left coil is about 52 ms, and the opening time of the solenoid valve on the right coil is about 44 ms. The reaction time of the valve spool is suitable for the practical application of the solenoid valve. The significance of this paper is the reduced radial size of the three-bit four-way electromagnetic insertion valve. These improvements have reduced the size of downhole drilling robots, which facilitates the application of downhole drilling robots in narrower environments. [ABSTRACT FROM AUTHOR]

This paper presents an experimental setup of magnetic field taper variations to optimize the efficiency of a Ka-band pulsed gyrotron. Experimental optimization of the gyrotron's efficiency is presented. The efficiency dependence on three input parameters—beam current, magnetic field amplitude, and variations in the magnetic field taper profile—is studied. A gyrotron electron efficiency improvement from 25.4% for a non-tapered magnetic curve to 36.4% for a tapered magnetic curve is measured. The stability of the millimeter wave excitation in the cavity is also affected by the magnetic taper gradient. The magnetic taper is obtained by a practical modification of the solenoid that leads to an 11% electron efficiency improvement. Magnetic tapering can be combined with other types of efficiency enhancement concepts to obtain an overall improved efficiency that can be important for industrial applications. [ABSTRACT FROM AUTHOR]

• Commercial-of-the shelf (COTS) space qualified solenoid valves for small satellite missions are financially unviable. • Thrusters control spacecraft attitude, the response time, and parameters of the solenoid valve is critical in mission design. • A mathematical model was developed to find the optimized geometrical configuration of the solenoid valve. • This paper presents a practical solution for designing custom solenoid valves. • The developed mathematical model validated using COTS space qualified solenoid valves. Small satellites and spacecrafts use propulsion systems to stabilize their attitude, control orientation and deorbit it at the end of the mission life. The flow and thrust of the liquid propulsion system are controlled by the control valve, typically operated by solenoid. According to recent literature, space-qualified solenoid valves are expensive and financially non viable, especially for small satellite missions. In this paper, a detailed methodology is presented to design the solenoid valve dedicated for small satellites. This study includes design criteria focusing on geometrical configuration. The dynamic, and electro-magnetic models are used to characterize the solenoid valve. Dynamic modelling helps to determine the response time of valve, affecting the thruster minimum impulse bit. The physical dimensions of the designed solenoid valve are smaller than those available in commercial off-the shelf (COTS) solenoid valves. However, the efficacy of the proposed design is proven effective with the COTS space grade valve specifications, and it shows that the proposed valve consumes less power than the conventional valves. Finally, it is worth noting that despite their modest and compact physical dimensions, the proposed valve are ideal for small satellite missions. [ABSTRACT FROM AUTHOR]

This article is about the periodic points characterization of automorphisms of some solenoids, whose duals are subgroups of algebraic number fields. Here, we use the theory of adeles for describing a solenoid and the periodic points of its automorphisms. This is in line with the earlier characterizations which considered other classes of solenoids. [ABSTRACT FROM AUTHOR]

In order to solve the problems of bottom pod leakage and soil removal by header, a soybean header profiling system was designed in this paper. The cutter height off-ground detection device was installed on both sides of the header, and the cutter distance from the ground was represented by the angle sensor turning when the profiling wheel met the rolling ground. The hydraulic electromagnetic reversing valve was installed so that the profiling system could automatically control the lifting of the header, the unilateral power of the solenoid valve was 0.15 s, and the height of the cutter from the ground was changed by 10 mm. The height of the cutter off the ground was set to 80 mm, and the adjustment range of the soybean header profiling system was 45–125 mm. The test results showed that the maximum absolute error of the cutter off the ground height detection device was 5.98 mm, the minimum absolute error was 1.00 mm, and the relative error was 0.038. The cutter height adjustment device was powered for 0.15 s, and the average adjustment distance was 11.158 mm. The soybean header profiling system did not shovel soil during field harvest, and the stubble height of 85% of soybean plants was less than 10 mm from the set height after harvest. The results showed that the soybean header profiling system could effectively adjust the cutter height from the ground so that the cutter height from the ground was kept at 80 mm. This study could provide a reference for the intelligent design of soybean harvesters. [ABSTRACT FROM AUTHOR]

An effective approach to high-sensitivity magnetic field detection under low-frequency excitation by soft magnetic ribbons and a rectangular solenoid is proposed and certificated. The solenoid wound by nonmagnetic copper wire is located at the geometric center region of the soft magnetic ribbons that act as the magnetic core. The proposed magnetic sensor utilizes the nonlinear magnetization of soft magnetic ribbons and the magneto-inductive effect and proximity effect of the solenoid, exhibiting significant impedance variation at a relatively low frequency. The impedance ratio and impedance sensitivity of the prototype reaches the maximum value of 5630% and 570% Oe−1 at 500 kHz, which is far superior to the conventional giant magneto-impedance (GMI) magnetic sensor and planar coil laminated GMI magnetic sensor. The investigation indicates the fabricated magnetic sensor with optimal dimension parameters can provide a sensitivity of 3329 mV Oe−1 at 500 kHz. More importantly, the proposed prototype is particularly suitable for micromachining, providing the possibility for manufacturing high-sensitivity micro-magnetic sensors. [ABSTRACT FROM AUTHOR]

A model-based study is conducted to optimize the dynamic performance of a solenoid actuator in a compressed natural gas (CNG) injector. A mechanical model, an electromagnetic model, and an optimum model using particle swarm optimization (PSO) algorithm are built to depict operation and optimize the dynamic response times of the injector solenoid actuator. Effects of the number of coil turns (N), spring stiffness (k), and gap between plunger and cylinder wall (g), on the dynamic characteristics of the injector solenoid actuator are investigated. Simulation results show that, when k increases from 560 to 2560 N/m, and g increases from 0.1 to 0.5 mm, the opening response time increases 35.41% and 48.03%, respectively; however, the closing response time of the injector solenoid actuator reduces 27.27% and 45.25%, respectively. When N is increased from 342 to 552, the opening response time reduces 35.48%; nevertheless, the closing response time increases considerably with a 195.45% increment. Using PSO algorithm, it is found that the optimum version of the injector solenoid actuator has improvements for both opening and closing response times, in which the opening response time reduces 11.41% when compared with the original version. [ABSTRACT FROM AUTHOR]

High performance of clutch control is essential for dual-clutch transmission (DCT) system to ensure good shifting smoothness of vehicle driving. The control performance of clutch in DCT driven by proportional solenoid valve depends on the output pressure control of the solenoid valve, while the output pressure of the solenoid valve is directly controlled by the energized current. Therefore, the relationship between working current and output pressure of the solenoid valve has significant impact on the clutch control and affects driving performance of the vehicle accordingly. However, the pressure-to-current (P/I) relationship of proportional solenoid valve has nonlinear hysteresis characteristic caused by magnetic materials, oil viscous friction, operation temperature, etc., which has negative effects on the accuracy and stability of solenoid valve pressure control. To cope with this problem, a machine learning model called long short-term memory (LSTM) for P/I of solenoid valve based on data mining is adopted in this paper, which is then used as feedforward compensation for closed-loop control of solenoid valve. The test result demonstrates that the machine learning model can effectively predict the output pressure at rising and falling phase of the same working current. Besides, this smart control method which has better applicability in engineering can effectively improve the control performance of proportional solenoid valve and further improve clutch control and vehicle driving performance. [ABSTRACT FROM AUTHOR]

ENN Science and Technology Development Co., Ltd. (ENN) is committed to generating fusion energy in an environmentally friendly and cost-effective manner, which requires abundant aneutronic fuel. Proton-boron (p-11B or p-B) fusion is considered an ideal choice for this purpose. Recent studies have suggested that p-B fusion, although challenging, is feasible based on new cross section data, provided that a hot ion mode and high wall reflection can be achieved to reduce electron radiation loss. The high beta and good confinement of the spherical torus (ST) make it an ideal candidate for p-B fusion. By utilizing the new spherical torus energy confinement scaling law, a reactor with a major radius R 0 = 4 m, central magnetic field B 0 = 6 T, central temperature T i 0 = 150 keV, plasma current I p = 30 MA, and hot ion mode T i / T e = 4 can yield p-B fusion with Q > 10. A roadmap for p-B fusion has been developed, with the next-generation device named EHL-2. EHL stands for ENN He-Long, which literally means "peaceful Chinese Loong." The main target parameters include R 0 ≃ 1.05 m, A ≃ 1.85 , B 0 ≃ 3 T, T i 0 ≃ 30 keV, I p ≃ 3 MA, and T i / T e ≥ 2. The existing ST device EXL-50 was simultaneously upgraded to provide experimental support for the new roadmap, involving the installation and upgrading of the central solenoid, vacuum chamber, and magnetic systems. The construction of the upgraded ST fusion device, EXL-50U, was completed at the end of 2023, and it achieved its first plasma in January 2024. The construction of EHL-2 is estimated to be completed by 2026. [ABSTRACT FROM AUTHOR]

The use of solenoid magnets in welding processes has attracted attention due to their potential to influence the properties of welded joints. This research investigates the effect of the size of the magnetic induction solenoid on the tensile strength and impact toughness of welds between mild steel and medium carbon steel. Welding experiments were carried out using various sizes of solenoid magnets (0; 1.71mT; 2.11mT; 2.31mT; 2.60mT), and the welding results were tested for tensile strength and impact toughness. The findings show that the size of the magnetic induction solenoid has a significant effect on the mechanical properties of the weld. The larger induction size in this study increased the tensile strength of the welded joint, namely 431.576 N/mm2 without induction and 533.33 N/mm2 with induction. Meanwhile, the impact toughness of welded joints also increases, namely 95.92N.m without treatment and 217.35N.m with induction. [ABSTRACT FROM AUTHOR]

In view of the problem that the output thrust of the solenoid actuator is affected by various factors and is difficult to calculate in actual working conditions, this paper proposes a semi-analytical model constructed by magnetic field subdomain method with internal and external boundary conditions in a cylindrical coordinate system for calculation, and the general solution equations of magnetic vector potential for each subdomain are derived and solved by MATLAB. Taking a push–pull electromagnet as an example, the finite element simulation and experimental comparative analysis are carried out. The correctness and applicable conditions of the subdomain method are illustrated by comparing the gradient plot of magnetic vector potential, inductance curve and electromagnetic force. It is shown that the results calculated by the subdomain method are very close to the finite element method when the magnetic saturation problem is neglected. However, when the nonlinearity of core permeability is considered, the magnetic saturation gradually deepens with the increase in current, and the error of the subdomain method calculation results gradually increases. Through simulation and experimental verification at slight magnetic saturation, the output thrust after considering the core gravity, spring force and electromagnetic force, it is shown that this method has the advantage of computational flexibility compared with the finite element method, and it is easier to write special algorithms according to various working conditions to calculate the important parameters in engineering applications. [ABSTRACT FROM AUTHOR]

Introduction: During the COVID-19 pandemic, ventilator shortages necessitated the development of new, low-cost ventilator designs. The fundamental requirements of a ventilator include precise gas delivery, rapid adjustments, durability, and user-friendliness, often achieved through solenoid valves. However, few solenoid-valve assisted low-cost ventilator (LCV) designs have been published, and gas exchange evaluation during LCV testing is lacking. This study describes the development and performance evaluation of a solenoid-valve assisted low-cost ventilator (SV-LCV) in vitro and in vivo, focusing on gas exchange and respiratory mechanics. Methods: The SV-LCV, a fully open ventilator device, was developed with comprehensive hardware and design documentation, utilizing solenoid valves for gas delivery regulation. Lung simulator testing calibrated tidal volumes at specified inspiratory and expiratory times, followed by in vivo testing in a porcine model to compare SV-LCV performance with a conventional ventilator. Results: The SV-LCV closely matched the control ventilator's respiratory profile and gas exchange across all test cycles. Lung simulator testing revealed direct effects of compliance and resistance changes on peak pressures and tidal volumes, with no significant changes in respiratory rate. In vivo testing demonstrated comparable gas exchange parameters between SV-LCV and conventional ventilator across all cycles. Specifically, in cycle 1, the SV-LCV showed arterial blood gas (ABG) results of pH 7.54, PCO2 34.5 mmHg, and PO2 91.7 mmHg, compared to the control ventilator's ABG of pH 7.53, PCO2 37.1 mmHg, and PO2 134 mmHg. Cycle 2 exhibited ABG results of pH 7.53, PCO2 33.6 mmHg, and PO2 84.3 mmHg for SV-LCV, and pH 7.5, PCO2 34.2 mmHg, and PO2 93.5 mmHg for the control ventilator. Similarly, cycle 3 showed ABG results of pH 7.53, PCO2 32.1 mmHg, and PO2 127 mmHg for SV-LCV, and pH 7.5, PCO2 35.5 mmHg, and PO2 91.3 mmHg for the control ventilator. Conclusion: The SV-LCV provides similar gas exchange and respiratory mechanic profiles compared to a conventional ventilator. With a streamlined design and performance akin to commercially available ventilators, the SV-LCV presents a viable, readily available, and reliable short-term solution for overcoming ventilator supply shortages during crises. [ABSTRACT FROM AUTHOR]

This paper proposes a new condition indicator (CI) for cost-effective industrial direct current (DC)-powered solenoid valves (SVs). First, a literature review of the failure modes for SVs is reported. The failure regarding the impeded movement of the valve plunger is considered. The proposed CI for this failure mode is computed from only some significant points of the SVs excitation current and their time instants. The proposed CI is evaluated by a large endurance campaign on a set of SVs. Then, a Remaining Useful Life (RUL) estimation algorithm is proposed and evaluated on the experimental data. Experimental results show the goodness of the proposed CI for RUL estimation of cost-effective industrial DC SVs. [ABSTRACT FROM AUTHOR]

McKibben pneumatic actuators (MPAs) are soft actuators that exert tension by applying compressed air to expand a rubber tube. Although electro-pneumatic regulators can control air pressure, most are large and expensive. This study utilizes a dynamic quantizer to control the MPA with a small solenoid valve that can only open and close the valve instead of an electro-pneumatic regulator. A dynamic quantizer is one of the quantizers that converts continuous signals to discrete signals. Our previous study confirmed that tension control of MPA under isometric conditions could be realized using a dynamic quantizer. However, it is often necessary to control the length of the MPA as well as the tension of the MPA. This study implements a dynamic quantizer to control the length of the MPA with a small solenoid valve. Numerical simulations and experimental tests verify the effectiveness of the proposed method. The results of the numerical simulations and experimental tests confirmed that the length of the MPA can be controlled using the dynamic quantizer. [ABSTRACT FROM AUTHOR]

This paper describes the procedure for creating a electronic simulation model of a solenoid power electronic driver with a nonlinear inductive load. Furthermore, it discusses the electromagnetic interaction between the driver and the load example electromagnetic valve. The consideration of nonlinear effects in the power electronic components MOSFET and diode is particularly important to distinguish their effects from the nonlinear behaviour of the inductive load. [ABSTRACT FROM AUTHOR]

A fundamental understanding of the theory and measurement procedures for characterizing a solenoid is crucial for making a project cost-effective and achieving the desired performance for its use in a LINAC. This paper attempts to comprehend the beam dynamics of charged particles by considering the conservation of canonical angular momentum, which can take on positive, negative, and zero values. The analytical expression to generate a parallel beam using a solenoid is derived. The effect of the final beam size on the values of a solenoid's spherical aberration coefficient and the position of the minimum beam size with respect to the focal length is studied using electron trajectories. A practical procedure to tune the above two parameters of a solenoid is demonstrated by simply modifying the demountable disks connected at each end. A mathematical model is proposed to accurately determine the axis of a solenoid and the magnetic centre using the measured magnetic field data, which is validated experimentally. Several solenoids, used in the 9.5 MeV 10 kW electron LINAC suitable for sterilizing medical products and food irradiation, have been characterised using this procedure. [ABSTRACT FROM AUTHOR]

Spot sprayers that can distinguish between different types of plants, such as weeds and crops, have recently been introduced into the field. These sprayers are all equipped with a system capable of recognising and spraying individual plants. These components are not included in existing test procedures for testing sprayers in use. In order to investigate the applicability of existing test procedures, the Ecorobotix spot sprayer was tested according to EN ISO 16122. With a few exceptions due to additional functionalities, this standard is well suited for carrying out such a test on spot sprayers in use. The entire electronic detection system, consisting of camera, computer and solenoid valve system, has to be tested with new test procedures. The positive experience with the use of protocols for band sprayers leads to the conclusion that they can also be applied to the testing of spot sprayers, but must be extended to test the new elements of these sprayers. [ABSTRACT FROM AUTHOR]

The basic physics of magnetic fields is presented for a target audience of NMR workers. This group often does not have formal training in electromagnetism, but could benefit from an understanding of a selected subset of topics. The focus here is on a relatively non-mathematical view, intended to deliver an intuitive understanding of the topic. The covered topics start with the fields arising from simple idealized currents, including long straight wires, short flat coils, infinite current sheets, long solenoids, and magnetic dipole moments. The generation of field gradients and shim fields is discussed. All of these can be unified by considering the divergence and curl of the magnetic field. Magnetic materials are treated, both linear magnetizable materials (including the sample itself) and permanently magnetized materials; the approaches of equivalent currents and Ampere's theorem for magnetic circuits are presented.

The magnetic field method for preparing aligned steel fiber-reinforced concrete (ASFRC) by solenoid coil has a limitation, which is that the specimen must be placed inside the solenoid coil, limiting its practical engineering application. To overcome this shortcoming, this study proposes a method for preparing ASFRCs using an external magnetic field created by assembled magnets. A theoretical model is proposed to predict the distribution of the external magnetic field and the orientation coefficient of ASFRCs prepared by assembled magnets. The predicted results are compared with the experimental results to verify the proposed model. Finally, flexural tests are used to compare the mechanical characteristics of ASFRCs prepared using assembled magnets and solenoid coil. The results indicate that the assembled magnets can be used to prepare the ASFRC with an orientation coefficient of 0.9 or higher, and the flexural strength is similar to that of the ASFRC prepared by the solenoid coil. [ABSTRACT FROM AUTHOR]

Atomic bandpass filters are used in a variety of applications due to their narrow bandwidths and high transmission at specific frequencies. Predominantly, these filters are in the Faraday (Voigt) geometry, using an applied axial (transverse) magnetic field with respect to the laser propagation direction. Recently, there has been interest in filters realized with arbitrary-angle magnetic fields, which have been made by rotating permanent magnets with respect to the k-vector of the interrogating laser beam. However, the magnetic field angle achievable with this method is limited as field uniformity across the cell decreases as the rotation angle increases. In this work, we propose and demonstrate a new method of generating an arbitrary-angle magnetic field, using a solenoid to produce a small, and easily alterable, axial field, in conjunction with fixed permanent magnets to produce a large transverse field. We directly measure the fields produced by both methods, finding them to be very similar over the length of the vapor cell. We then compare the transmission profiles of filters produced using both methods, again finding excellent agreement. Finally, we demonstrate the sensitivity of the filter profile to changing magnetic field angle (solenoid current), which becomes easier to exploit with the much improved angle control and precision offered by our new design. [ABSTRACT FROM AUTHOR]

The evolution of programmable controllers, PLCs, has allowed the digital approach to hydraulic and pneumatic applications made with proportional devices. Thus, the presence of built-in PWM (Pulse Width Modulation) blocks in most PLCs allows the direct control of the valve coils, using a simple electrical circuit to adapt the digital output of the PLC to the solenoid of the proportional device. This paper presents the calculus of the parameters for PWM drive according to the parameters of the proportional solenoid valve. An original method of increasing the native resolution of the PWM block is also presented. [ABSTRACT FROM AUTHOR]

This paper focuses on the efficiency of the double-acting hydraulic cylinders with shock absorber at stroke end. In the present work, the simulation of two hydraulic circuits and an electro-hydraulic circuit with double-acting cylinders with shock absorber is studied. Thus, the first hydraulic circuit is made of the following components: tank, throttle check valve, 4/2-way hand lever valve with spring, filter, fixed displacement pump, and double-acting cylinder with shock absorber at stroke end (Dacs 1-1). The second hydraulic scheme has the following devices: pump unit, throttle valve, 4/3-way hand lever valve, and two double-acting cylinders with shock absorber at stroke end (Dacs 2-1 and Dacs 2-2). The third circuit studied is an electro-hydraulic scheme. The last scheme is made of the following components: tank, 4/3-way solenoid valve, nozzle, relay, valve solenoid, lamp, capacitive proximity switch, and double-acting cylinder with shock absorber (Dacs 3-1). [ABSTRACT FROM AUTHOR]

We study the decay of correlations for certain dynamical systems with non-uniformly hyperbolic attractors, which natural invariant measure is the Sinai-Ruelle-Bowen (SRB) measure. The system $ g $ that we consider is produced by applying the slow-down procedure to a uniformly hyperbolic diffeomorphism $ f $ with an attractor. Under certain assumptions on the map $ f $ and the slow-down neighborhood, we show that the map $ g $ admits polynomial upper and lower bounds on correlations with respect to its SRB measure and the class of Hölder continuous observables. Our results apply to the Smale-Williams solenoid, as well as its sufficiently small perturbations. [ABSTRACT FROM AUTHOR]

Brakes are essential parts of any system that involves motion. A few seconds are spent applying the brake, accumulating enough force to retard a system. In case of emergency stops, we need an efficient braking system that acts quickly and safely to avoid any mishaps. This work aims to develop a prototype of an instantaneous braking system, which can stop the motion of a rotating member. The operating principle of the device is the electromagnetic actuation of a solenoid. The actuation of a solenoid is simple and instantaneous. As a result, we could achieve immediate braking of a rotating member. [ABSTRACT FROM AUTHOR]

A proportional valve is one of the important parts used by the hydraulic control system to make precise operations. Flow control and direction are functions of proportional directional control valves. Despite this being important there are some problems, such as in flow control. This operation may cause the deficient performance of the actuator and the system. This paper presents the improvement of the performance hydraulic proportional directional control valve. The work suggests that the proportional valve would only be able to control flow in one direction, either metering in or out. Accordingly, the proposed work arrangement suggests many types of setups, by adding two-way directional control valves. Firstly, to know how the performance is deficient, some case is studied analytically. To demonstrate that, the prepared proposal has been made. The setup of the proposed arrangement is achieved. The arrangement is subject to simulation and tested practically to study the performance. The work included the electronic setup. As a result, the work leads to the improvement of the operation of proportional valves to control flow in one direction. The result of this investigation is to think about a new sort of valve that might be created to function better. As well as can also be made more flexible operations, depending on the type of load effect and flow control needed. In conclusion, the valve operation can be used as meter-in or meter-out flow controlling. [ABSTRACT FROM AUTHOR]

This study explores a super-fast magnetic abrasive finishing (MAF) process for polishing the surface of an Inconel 625 bar workpiece for a hydrogen solenoid valve stem. The Inconel 625 bar was chosen to replace the existing STS 316 bar material, previously used for a hydrogen solenoid valve stem. The cylindrical surface of Inconel 625 bars was polished by a super-fast MAF process with high rotational speeds of 1000, 5000, 15,000, and 25,000 RPM and a super-strong magnetic field of 550 mT. The polishing characteristics of this process were evaluated according to the type of abrasives, rotational speeds of the workpiece and processing time. As a result, a super-smooth Inconel 625 bar was successfully achieved, with a surface roughness (Ra) reduced from 0.31 μm to 0.02 μm under the optimal conditions (15,000 RPM, CNT particles (0.04 μm), PCD diamond abrasive (1 μm), Fe (#200), 0.5 g of light oil, and 16 min of processing time). Also, the Ansys analysis results showed suitable strain, equivalent stress, and safety factor of the Inconel 625 bar. This confirmed that, after a super-fast MAF process, an Inconel 625 bar is feasible for application in Hydrogen (H2) tanks instead of a conventional STS 316 bar. [ABSTRACT FROM AUTHOR]

In this paper, a numerical simulation model of the flow field inside the diaphragm valve is established based on the k-ε turbulence model (where k represents the turbulent kinetic energy and ε represents the turbulent dissipation rate). The mass flow at the inlet and static pressure at the outlet are used as the numerical calculation conditions, and the accuracy of the model is verified through experiments. Based on this, the model is applied to analyze the internal flow characteristics and pressure field distribution of the valve body under different import flow rates (2.787-33.273 kg/s), and an accurate quantitative relationship between import flow rate and valve body head loss is established. The results show that: 1 the numerical simulation can better predict the head loss of the valve body under different flow conditions. When the inlet flow numbers are 5.546, 11.091 and 16.637 kg/s respectively, the relative errors between the experimental and numerical simulations are only -6.433%, 4.619%, and 7.264%. 3 With a constant inlet flow, the static pressure decreases from inlet to outlet in flow passage. Flow contraction caused by the blockage of the valve wall and the flow impinging on the diaphragm creates a large static pressure gradient in the valve body. 4 After water passes through the narrow flow channel on the valve wall, a cavitation zone and reflux phenomena occur downstream of the valve body. The cavitation zone appears mainly in the 1/3 fluid domain away from the outlet. As the inlet flow increases, the vortex in the downstream of the valve body intensifies and the reflux phenomenon becomes more significant, but the scope of the reflux zone does not increase significantly. 2 After verifying the accuracy of the model, this paper studies the valve body's internal flow characteristics and pressure field distribution under 18 different inlet flow conditions. The model establishes a relationship between the inlet mass flow Q and the head loss ΔP of the valve body. For Reynolds numbers from 37 927-21 5984 and inlet mass flow Q from 2.787-15.428 kg/s, the fitting equation is ΔP = 2 076.31Q - 7 567.49 (R² = 0.964). For Reynolds numbers from 240 097-467 009 and inlet mass flow Q from 17.141-33.273 kg/s, the fitting equation is ΔP = 5 688.02Q - 67 317.39(R² = 0.993). These results are useful for hydraulic calculations in irrigation systems. [ABSTRACT FROM AUTHOR]

Solenoid connectors play important role in electronic stability system design, with the features of small size, low cost, fast response time and high reliability. The main production process challenge for solenoid connectors is the accurate detection of defects, which is closely related to safe driving. Both faultless and defective products have similar color and shape at the defect location, making proper inspection challenging. To address these issues, we proposed a defect detection model called PO-YOLOv5 to achieve accurate defect detection for solenoid connectors. First, an additional prediction head was added to enable the model to acquire more semantic information to detect larger-scale defective features. Second, we introduced dynamic convolution to learn complementary connections between the four dimensions of the convolution kernel by utilizing its multidimensional attention mechanism. Replacing conventional convolution with dynamic convolution enhances the detection accuracy of the model and reduces the inference time. Finally, we validated PO-YOLOv5 versus the state-of-the-art object detection methods on the same solenoid connectors dataset. Experiments revealed that our proposed approach exhibited higher accuracy. The mAP (mean Average Precision) result of PO-YOLOv5 was found to be about 90.1%. Compared with the original YOLOv5, PO-YOLOv5 exhibited improved precision by about 3%. [ABSTRACT FROM AUTHOR]

Under high-frequency operating conditions, the high-speed solenoid valve (HSV) experiences energy loss and heat generation, which significantly impacts its operational lifetime. Reducing the energy loss of an HSV without compromising its opening response characteristics poses a significant challenge. To address this issue, a finite element simulation model of an HSV coupled with a current feedback model is constructed to investigate the synergistic effects of dynamic response and energy loss. Prediction models for the opening response time, HSV driving energy, and Joule energy using a back propagation neural network (BPNN) are established. Furthermore, a multi-objective optimization study on the current driving strategy using a non-dominated sorting genetic algorithm II (NSGA-II) is conducted. After optimization, although there was a 6.24% increase in the opening response time, both HSV drive energy and Joule energy were significantly reduced by 15.67% and 22.49%, respectively. The proposed multi-objective optimization method for an HSV driving strategy holds great significance for improving its working durability. [ABSTRACT FROM AUTHOR]

Motorcycle experiences different vibrations on different road conditions. In order to improve the problem that the classical control algorithm cannot perfectly balance the driving comfort and road-holding performance when the motorcycle is driving in different road conditions, the hybrid control algorithm based on frequency division (HCFD) is designed. Firstly, the single-axis two-degree-of-freedom suspension model of motorcycle semi-active suspension system (SASS) and the look-up table model of solenoid valve damper are established. After that, the classical SASS control algorithms such as skyhook and groundhook are analyzed. HCFD is designed and verified for its inability to perfectly balance the comfort and road-holding performance of motorcycle. Finally, a real motorcycle experimental platform is built using the rapid control prototype (RCP) based on dSPACE, and the HCFD is tested and verified on washboard roads. The experimental results show that the SASS using the HCFD not only enhances driving comfort but also effectively mitigates concerns related to a decline in road-holding performance. The HCFD has practical significance to improve the comprehensive performance of motorcycle SASS. [ABSTRACT FROM AUTHOR]

This study reports fully 3D-printed, three-dimensional, soft magnetic-cored solenoids that generate three times the largest magnetic fields previously reported from 3D-printed solenoids. The devices are fabricated on a customised, multi-material 3D printer that can extrude both filaments and pellets. Three different kinds of materials are employed to manufacture the reported soft magnetic-cored solenoids: pure PLA (dielectric portions), PLA doped with copper particles (electrically conductive structures), and nylon or PLA doped with metallic particles (soft magnetic cores). Via manufacturing optimisation, the reported devices are 33% smaller and can withstand about twice the current, generating three times more magnetic field. The 3D-printed solenoids generate Gauss-level magnetic fields while drawing tens-of-milliamps currents and can be readily used to implement fully 3D-printed induction sensors. The results of this work extend the state of the art in 3D-printed electronics, enabling the creation of more complex and capable solenoids for in-situ manufactured and in-space manufactured electromagnetic systems. [ABSTRACT FROM AUTHOR]

Radio frequency quadrupole coolers (RFQCs) are very suitable to cool ion beams with moderate energy spread, typically ions of exotic nuclear species (like $^{132}$ Sn $^{1+}$) as in the Selective Production of Exotic Species project at the Laboratori Nazionali di Legnaro, whose ion source supplies 40 keV ions. Beam dynamics includes ion–gas collisions (with a balance of cooling and diffusion effects), acceleration and deceleration and radiofrequency confinement, which can be supplemented by static magnetic field effects. Insertion of a prototype RFQC in the solenoid of the Eltrap machine is also discussed here, with innovations in beam extraction and in modelling, now also based on stochastic equations. Practical consideration on gas pumping and voltage distribution are also included. Typical limits of RFQC are discussed, with special attention to the extracted beam root mean square emittance, which is shown to strongly depend not only on cooler parameters, but also on extraction optics. [ABSTRACT FROM AUTHOR]

The dynamic response and operational reliability of high-speed solenoid valve (HSV) for diesel engine injector are the main indicators to measure their performance. At high-frequency, the eddy current energy and Joule energy generated by the HSV will be converted into heat, which has a significant impact on the service life of HSV. The optimization of HSV involves the interaction between energy loss and the dynamic response of HSV. To optimize the HSV dynamic response time considering energy loss, the HSV work process simulation model was established in this paper, and the model was verified based on armature lift experimental data. Without changing the structural parameters of the HSV, the four parameters of electroconductibility, spring stiffness, damping coefficient, and coil resistance were selected as the key parameters affecting the dynamic response and energy loss. The response surface models (RSMs) of opening response time, closing response time, eddy current energy and Joule energy of the HSV were constructed by using the smoothing spline-analysis of variance method. The multi-objective cooperation optimization of HSV under the interaction of dynamic response characteristics and energy loss was completed by using non-dominated sorting genetic algorithms. After optimization, the opening and closing response times of HSV were reduced by 15.1% and 16.6% respectively, while the eddy current energy and Joule energy were reduced by 5.2% and 48.4% respectively. In this paper, the dynamic response and energy loss were jointly optimized. The presented results provide theory instruction for multi-objective cooperative optimization of HSV. [ABSTRACT FROM AUTHOR]

In this study, the performance of a long-stroke moving-iron proportional solenoid actuator (MPSA) was improved by combining numerical simulations and experiments. A finite element model of the MPSA was developed; its maximum and mean relative absolute errors of electromagnetic force were 4.3% and 2.3%, respectively, under typical work conditions. Seven design parameters including the cone angle, cone length, depth of the inner hole of the coil skeleton, cone width of the armature, inner cone diameter, and initial position of the moving-iron core were selected for developing the model, and the coefficient of the variation in electromagnetic force, nominal acceleration, 95% of the maximum stable output electromagnetic force, and corresponding response time were used as the performance indicators. The constraint relation between each performance indicator and the influence of each design parameter on the performance indicators were revealed using the uniform Latin hypercube experiment design, correlation analysis, and the main effect analysis method. A multi-objective optimization mathematical model of the MPSA was developed by combining traditional surrogate and machine learning models. The Pareto solution set was obtained using the nondominated sorting genetic algorithm II (NSGA-II), and three decision schemes with different attitudes were determined using the Hurwicz multi-criteria decision-making method. The results showed that a strong contradiction exists among the 95% of the maximum stable output electromagnetic force and its corresponding response time and the coefficient of the variation in electromagnetic force. The cone angle considerably influenced the performance indicators. Compared with the initial design, the coefficient of the variation in electromagnetic force was reduced by 54.08% for the positive decision, the corresponding response time was shortened by 15.65% for the critical decision, and the corresponding acceleration was enhanced by 10.32% for the passive decision. Thus, the overall performance of the long-stroke MPSA effectively improved. [ABSTRACT FROM AUTHOR]

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Students may calculate the mutual inductance between an infinite solenoid and a surrounding circular loop using an incorrect method that yields the correct answer, causing frustration and confusion. A physical explanation for the agreement of the two methods is provided that is based on the translational symmetry of the solenoid. As a consequence, the conclusion generalizes to infinite uniform solenoids of arbitrary cross section. When students obtain the right answer using an unjustified method, instructors are faced with a grading quandary. Finding himself in that situation, this author asked, "Why?" The resulting paper, which will be enjoyed by instructors of electromagnetism, shares the explanation, involving the mutual inductance of a solenoid and a loop. [ABSTRACT FROM AUTHOR]

The study of soft pneumatic actuator control techniques is an important research topic in soft robotics. However, much of the research has concentrated on upper-level control algorithms, with little attention paid to the bottom-level pneumatic controller. This work aims to develop a simple, low cost, and quick-response pressure controller for soft pneumatic actuators. The controller is designed based on an on/off valve-driven pneumatic supply system, which is high speed, economical, and easy to set up. Using the actual pneumatic properties of a controlled object to estimate the switching time of the valves, the controller avoids complex nonlinear pneumatic computation and can achieve a high control frequency. Experiments demonstrate that the controller performs well in terms of speed and precision, having practical value in the control of soft actuators. [ABSTRACT FROM AUTHOR]

Drastic changes in the random load of an electromechanical system bring about a reliability problem for the proportional solenoid valve based on a thermal effect. In order to accurately and effectively express the thermal load of a proportional solenoid valve under random load conditions and to meet the requirements of online acquisition, adaptive anomaly detection, and the missing substitution of thermal load data, a thermal load prediction model based on the Kalman filter algorithm is proposed. Taking the compound operation process of an excavator as the object and based on the field testing of an excavator and the independent testing experiment of a proportional solenoid valve in a non-installed state, a method of obtaining historical samples of the proportional solenoid valve's power and thermal load is given. The k-means clustering algorithm is used to cluster the historical samples of the power and thermal load corresponding to the working posture of a multi-tool excavator. The Grubbs criterion is used to eliminate the outliers in the clustering samples, and unbiased estimation is performed on the clustering samples to obtain the prediction model. The results show that the cross-validation of the sample data under the specific sample characteristics of the thermal load model was carried out. Compared with other methods, the prediction accuracy of the thermal load model based on the Kalman filter is higher, the adaptability is strong, and the maximum prediction deviation percentage is stable within 5%. This study has value as a reference for random cycle thermal load analyses of low-frequency electromechanical products. [ABSTRACT FROM AUTHOR]

The solenoid valve for traction control valve (TCV) responsible for the automatic vehicle hold (AVH) function of electric vehicles require a continuous supply of power to the magnetic coil in order to operate. When power is continuously supplied, heat is generated because of the resistance of the magnetic coil, which leads to deterioration of the periphery of the solenoid valve and deteriorates durability. To prevent this, when power is applied to the solenoid valve for TCV for more than a certain period of time, the power supply is automatically turned off and the AVH function is controlled to be performed by the electronic parking brake (EPB). In this study, we designed, manufactured, and verified the permanent magnet solenoid valve of TCV for AVH that can minimize unnecessary power consumption of electric vehicle batteries. For the design of the permanent magnet solenoid valve, the location, polarity direction and specifications of the permanent magnet within the solenoid valve were studied through finite element analysis. In order to check whether the braking function by the permanent magnet is maintained even when the current is cut off at AVH's TCV solenoid valve, electronic control unit (ECU) and electronic stability control (ESC) were manufactured and evaluated for actual vehicle testing. Therefore, it was possible to manufacture a permanent magnet solenoid valve that minimizes unnecessary power consumption of the battery because it does not require power supply even when the car is stopped for a long time in the AVH function of the electric vehicle. [ABSTRACT FROM AUTHOR]