Wire Terminals Research Articles

LightYOLO: Lightweight model based on YOLOv8n for defect detection of ultrasonically welded wire terminations

Defect inspection of the surface in ultrasonically welded wire terminations is an important inspection procedure to ensure welding quality. However, the detection task of ultrasonic welding defects based on deep learning still faces the challenges of low detection accuracy and slow inference speed. Therefore, to solve the above problems, we propose a fast and effective lightweight detection model based on You Only Look Once v8 (YOLOv8n), named LightYOLO. Specifically, first, to achieve fast feature extraction, a Two-Convolution module with FasterNet block and Efficient multi-scale attention (CTFE) structures is introduced in the backbone network. Secondly, Group-Shuffle Convolution (GSConv) is used to construct the feature fusion structure of the neck, which enhances the fusion efficiency of multi-level features. Finally, an auxiliary head training method is introduced to extract shallow details of the network. To verify the effectiveness of the proposed method, we constructed a surface defect data set of ultrasonic welding wire terminals and conducted a series of experiments. The results of experiments show that the precision of LightYOLO is 93.4%, which is 3.5% higher than YOLOv8n(89.9%). In addition, the model size was reduced to 1/2 of the baseline model. LightYOLO shows the potential for rapid detection on edge computing devices. The source code and dataset for our project is accessible at https://github.com/JianshuXu/LightYOLO.

Experimental Investigation of Strain Rate Influence on Anisotropy of Uniaxial Tensile Mechanical Properties of CuFe2P Alloy Sheet.

Wire crimping, a process commonly used in the automotive industry, is a solderless method for establishing electrical and mechanical connections between wire strands and terminals. The complexity of predicting the final shape of a crimped terminal and the imperative to minimize production costs indicate the use of advanced numerical methods. Such an approach requires a reliable phenomenological elasto-plastic constitutive model in which material behavior during the forming process is described. Copper alloy sheets, known for their ductility and strength, are commonly selected as terminal materials. Generally, sheet metals exhibit significant anisotropy in mechanical properties, and this phenomenon has not been sufficiently investigated experimentally for copper alloy sheets. Furthermore, the wire crimping process is conducted at higher velocities; therefore, the influence of the strain rate on the terminal material behavior has to be known. In this paper, the influence of the strain rate on the anisotropic elasto-plastic behavior of the copper alloy sheet CuFe2P is experimentally investigated. Tensile tests with strain rates of 0.0002 s-1, 0.2 s-1, 1 s-1, and 5.65 s-1 were conducted on sheet specimens with orientations of 0°, 45°, and 90° to the rolling direction. The influence of the strain rate on the orientation dependences of the stress-strain curve, elastic modulus, tensile strength, elongation, and Lankford coefficient was determined. Furthermore, the breaking angle at fracture and the inelastic heat fraction were determined for each considered specimen orientation. The considered experimental data were obtained by capturing the loading process using infrared thermography and digital image correlation techniques.

Analisis Pengurangan Waste Proses Produksi Pada PT SP Manufacturing

PT SP Manufacturing is a manufacturing company that operates in the field of wire harness production. When making wire harnesses at PT SP Manufacturing, waste still occurs. Waste in the production process is one of the biggest problems this company wants to solve. A defective product is a product that does not meet wire harness production standards so it cannot meet customer demand, and requires more space before rework is carried out, which causes inventory waste (Unnecessary Inventory). Reduced productivity and higher production costs are the result of this waste. The aim of this research is to use value stream mapping to identify waste in the production process and apply lean manufacturing techniques to reduce it. The results obtained are based on identification and analysis of existing problems as well as alternatives and improvements based on the formulation and objectives in the research. The largest waste in the wire harness production process of PT.SP Manufacturing is waste with a weight score of 60.89%, unknown inventory waste with a weight score of 39, 12%. The causal factors are workers who lack concentration, apply excess solder paste to the wire terminals, workers who pursue targets without paying attention to quality, resulting in defective products that require rework. The recommendations given to the company according to the fishbone diagram are proposed improvements to the wire harness production process to reduce defects and unnecessary inventory which refers to people, machines, methods and materials.

An adaptive force and posture control strategy for automated wiring terminal assembly

ABSTRACT Mainstream industrial practice of assembling different flexible wires into the connector is manual due to different specifications of terminals and flexible wire assembly requirements. Therefore, the efficiency of the production and the quality of the assembly rely heavily on the knowledge and experiences of human workers. To reduce the labor cost and possible errors, this paper presents an adaptive force and posture control strategy for automated wiring terminal assembly (WTA). The contact force states during the search phase and insertion phase are first analyzed and then modeled. With the force analysis, fuzzy-PID controllers are applied for translational and angular adjustment during the assembly process. To validate the control strategy proposed, a prototype system is set up by integrating a force/torque (F/T) sensor and cameras on an industrial robot. And two kinds of industrial wires with four types of different wire terminals are tested with comparative studies. The results have shown that the proposed control strategy is able to conduct automatic insertion with different flexible wires successfully with reliable force feedback.

Controlling in-gap end states by linking nonmagnetic atoms and artificially-constructed spin chains on superconductors

Chains of magnetic atoms with either strong spin-orbit coupling or spiral magnetic order which are proximity-coupled to superconducting substrates can host topologically non-trivial Majorana bound states. The experimental signature of these states consists of spectral weight at the Fermi energy which is spatially localized near the ends of the chain. However, topologically trivial Yu-Shiba-Rusinov in-gap states localized near the ends of the chain can lead to similar spectra. Here, we explore a protocol to disentangle these contributions by artificially augmenting a candidate Majorana spin chain with orbitally-compatible nonmagnetic atoms. Combining scanning tunneling spectroscopy with ab-initio and tight-binding calculations, we realize a sharp spatial transition between the proximity-coupled spiral magnetic order and the non-magnetic superconducting wire termination, with persistent zero-energy spectral weight localized at either end of the magnetic spiral. Our findings open a new path towards the control of the spatial position of in-gap end states, trivial or Majorana, via different chain terminations, and the realization of designer Majorana chain networks for demonstrating topological quantum computation.

An experimental study on lap joining of multiple sheets of aluminium alloy (AA 5754) using friction stir spot welding

Friction stir spot welding (FSSW) process is widely used in the automotive industry for a range of applications such as battery components, standard wire connectors and terminals. This manuscript addresses two grand challenges in the arena of FSSW, hitherto, unaddressed in the extant literature: (i) lap joining of thin sheets (0.3 mm thickness) of AA 5754 alloy and (ii) lap joining of more than two sheets using FSSW. To accomplish this task, a novel pinless convex-shaped tool was designed to alter the stress state while gradually advancing the tool which led to achieving stress state necessary for obtaining defect-free lap joints. The weld joints were inspected by optical microscopy, SEM imaging and analysed by nanoindentation tests and Vickers microindentation tests for assessment of the quality of the weld interface (WI). Process parameters of FSSW such as torque on the tool and axially applied load were used to analytically obtain the average local measure of peak normal and axial stresses as well as the coefficient of friction in the contact zone. In samples welded at low rotational speeds, the strain-hardening mechanism was seen dominating in contrast to samples welded at higher rotational speeds, which showed thermal softening. As a direct consequence of this, the samples welded at low rotational speeds showed much higher hardness at the weld surface than the samples welded at higher speeds. A strong transition of strain hardening to thermal softening was noticeable beyond an applied strain rate of 400 s−1.

Integration of Robotic Vision and Tactile Sensing for Wire-Terminal Insertion Tasks

This paper reports the development of a manipulation system for electric wires, implemented by means of a commercial gripper installed on an industrial manipulator and equipped with cameras and suitably designed tactile sensors. The purpose of this system is the execution of wire insertion on commercial electromechanical components. The synergy between computer vision and tactile sensing is necessary because, in a real environment, the tight spaces very often prevent the possibility to use the vision system, also when the same task is performed by a human being. A novel technique to speed up the generation of training data sets for convolutional neural networks (CNNs) is proposed. Therefore, this technique is used to train a CNN in order to detect small objects (such as wire terminals). Moreover, aiming to prevent faults during the task and to interact with the environment safely, several machine learning approaches are used to produce an affordable output from the tactile sensor. The proposed approach shows how a cheap sensor embedded with suitable intelligence can provide information comparable to a more expensive force sensor. Note to Practitioners —This paper was motivated by the lack of commercial solution for the automatic cabling of switchgears. Existing approaches to this problem are in some way limited to specific large-scale products or simple layouts. This paper investigated a robust and flexible solution, based on the exploitation of multiple sensors and machine learning algorithms, for wire detection, grasping, and connection. The proposed approach is characterized by simple design and self-tuning capabilities, and it can be easily employed on a wide range of switchgear layouts thanks to the large workspace of the manipulator. Experimental results show that the proposed system is able to achieve a 95% success rate within a realistic admissible region. In the future research, we will integrate the proposed solution with an electromechanical component localization module and a terminal fastening system to evaluate the performance on the real production line.

Thermal transformation of printed circuit boards at 500 °C for synthesis of a copper-based product

This paper details the synthesis of copper-based products (i.e. Cu, Cu-Ni-Sn, Cu-Sn) from printed circuit boards (PCBs) using thermal transformation at 500 °C. The temperatures investigated in this paper are much lower than those used in conventional electronic waste smelting industries. This helps in reducing the energy requirements of the process opening up pathways for sustainable PCB processing technology. The resulting copper-based product comprises up to 94% metallic Cu, 2.5% Cu-Ni-Sn and 0.7% Cu-Sn alloys. Metallic Cu and Cu-Ni-Sn alloy are present in face centered cubic (FCC) form whereas Cu-Sn alloy possesses hexagonal closed packed (HCP) structure. XPS attests complete absence of oxides in metallic Cu. The copper product exhibits 4.57 × 107 ± 0.084 S m−1 electrical conductivity, equivalent to 78% IACS (International Annealed Copper Standard), which potentially enables its application in electrical switches or wire terminals. We have thus successfully developed a copper-based product from electronic waste, studied its properties and explored it from an application point of view.

Wireless Battery Management System of Electric Transport

Electric vehicles (EVs) are being developed and considered as the future transportation to reduce emission of toxic gas, cost and weight. The battery pack is one of the main crucial parts of the electric vehicle. The power optimization of the battery pack has been maintained by developing a two phase evaporative thermal management system which operation has been controlled by using a wireless battery management system. A large number of individual cells in a battery pack have many wire terminations that are liable for safety failure. To reduce the wiring problem, a wireless battery management system based on ZigBee communication protocol and point-to-point wireless topology has been presented. Microcontrollers and wireless modules are employed to process the information from several sensors (voltage, temperature and SOC) and transmit to the display devices respectively. The WBMS multistage charge balancing system offering more effective and efficient responses for several numbers of series connected battery cells. The concept of double tier switched capacitor converter and resonant switched capacitor converter is used for reducing the charge balancing time of the cells. The balancing result for 2 cells and 16 cells are improved by 15.12% and 25.3% respectively. The balancing results are poised to become better when the battery cells are increased.

Research on burnout fault of moulded case circuit breaker based on finite element simulation

In the failure event of molded case circuit breaker, overheating of the molded case near the wiring terminal has a very important proportion. The burnout fault has become an important factor restricting the development of molded case circuit breaker. This paper uses the finite element simulation software to establish the model of molded case circuit breaker by coupling multi-physics field. This model can simulate the operation and study the law of the temperature distribution. The simulation results show that the temperature near the wiring terminal, especially the incoming side of the live wire, of the molded case circuit breaker is much higher than that of the other areas. The steady-state and transient simulation results show that the temperature at the wiring terminals is abnormally increased by increasing the contact resistance of the wiring terminals. This is consistent with the frequent occurrence of burnout of the molded case in this area. Therefore, this paper holds that the burnout failure of the molded case circuit breaker is mainly caused by the abnormal increase of the contact resistance of the wiring terminal.

A Novel MEMS Device for Scanning Profile Measurement with Three Cantilever Displacement Sensors

A novel Micro Electro Mechanical System (MEMS) measurement device for straightness measurement with a three point method has been proposed. This device integrates three cantilever displacement sensors with a narrow pitch on a silicon chip. The authors determine appropriates shape, dimensions of the cantilever, and a fabrication process. According to simulation results, a triangular cantilever with altitude 12 mm long, base 4mm long, and 0.25 mm thickness was adopted to realize the target measuring range of 100 μm. Near the end of each cantilever, a square frustum probe 250 μm high which was fabricated by anisotropic wet etching was placed. Near the base of cantilevers, four piezo resistance gauges were formed; two are active gauges for measuring stress arise from a displacement at the probe and the others are dummy gauges for temperature compensation. Wiring and contact terminals were fabricated on the base substrate and the total size of the device is 20 mm × 32 mm. The fabrication process of this device was designed and result of a trial production was reported.

In situ tuning hydrostatic pressure at low temperature using electrically driven diamond anvil cell

Traditionally, a diamond anvil cell (DAC) operated at low temperature can be pressurized by using a helium-driven piston or remote control tightening mechanism. This approach of pressurizing DAC is not convenient for operating at low temperature. Here we develop a low-temperature pressurizing technique for in situ tuning pressure in DAC at 20 K by an electrically driven method. The improved DAC pressure apparatus is composed of traditional DAC device and a piezoelectric actuator (PZT). Here the PZT used in the experiment is the PSt 150/1010/40 supplied by the Piezomechanik. Both parts are assembled together in a red copper or stainless steel cylinder. The DAC part is thermally contacted with a low temperature holder for cooling the chamber of the DAC in the experiment. The wires of the PZT connect with the voltage source through the wiring terminals of the cryostat. As the DAC apparatus cools down, two electrodes of the PZT are connected together when a voltage difference between the electrodes is generated. When the temperature of the DAC chamber arrives at the presetting value, two electrodes of the PZT are connected with the voltage source for applying voltage to the PZT. In this paper, we find that the PZT stroke shows a linear increase with increasing voltage at 300 K, whereas it is approximately linear at 80 and 6 K. The maximum strokes are 40, 26 and 15 upm at 300, 80 and 6 K respectively when the applied voltage is 120 V. The experimental results show that the PZT-driven DAC apparatus can continuously generate pressure from 0.49 to 4.41 GPa at low temperature and applied voltage of 0-290 V, where at zero voltage an initial pressure of 0.49 GPa is generated by using driven screws of the DAC device at room temperature. The pressure in the DAC chamber is determined by the red shift of ruby florescence line. The calibrated chamber temperature in DAC is determined as a function of pressure (PZT voltage) by using the intensity ration (R2/R1) of ruby R2 and R1 fluorescence lines. We find that the chamber temperature only slightly increases with increasing pressure in a range of (19 1) K. The main difference between the present device and the other tuning DAC apparatus is that the force on the DAC can be conveniently applied by using PZT voltage. This guarantees a high pressure-tuned resolution in the experiment, e. g., we tune a single InAs quantum dot (QD) emission wavelength to match the cavity mode. Such a tuning technique is found to have applications in realizing a compact tunable single photon source or completing two-photon interference of Hong-Ou-Mandel experiments between the QD and nitrogen vacancy center in diamond or atom, respectively.

CARBON ATOMIC WIRES: FROM STARS TO NANOTECHNOLOGY

Carbon can produce a wide variety of systems and nanostructures with different dimensionality as exemplified by fullerenes, nanotubes and graphene, all with peculiar properties of great interest for fundamental and applied research. In this framework sp-hybridized carbon atoms can arrange to form atomic wires with size dependent functional properties. The sp form of carbon has a long story passing through astrophysics and minerals found in meteor craters and, although still considered elusive and unstable, nowadays a number of nano-systems constituted by or containing sp-carbon wires have been produced and characterized. As graphene is considered the thinnest material (one-atom thick), carbon atomic wires represent true 1-dimensional systems (one- atom diameter) with a great potential for nanoscience and nanotechnology. The status of research on carbon atomic wires is here discussed, starting from the description of ideal systems to real structures, showing that the properties can be tuned by controlling the wire length (i.e. number of carbon atoms) and termination (atom, molecular group or nanostructure). Synthesis techniques are presented as well as strategies to have stable wires. A particular attention will be given to the use of vibrational spectroscopy to provide insight on the structure and electronic properties of these systems. Perspectives for novel devices based on the exploitation of the electronic properties of these systems are also discussed.

Modeling of Energy Dissipation in RLC Current-Mode Signaling

In this paper, energy dissipation in resistance-inductance-capacitance (RLC) current-mode signaling is modeled. The energy dissipation is derived separately for driver, wire, and receiver termination. The effects of rise time and clock cycle are included. A realizable Π-model for the driving-point impedance of an RLC current-mode transmission line is derived. The output current of an RLC current-mode transmission line is also derived. The model is extended to multiple parallel coupled interconnects with inductive and capacitive coupling between them. The model is verified by comparing it to HSPICE in 65-nm technology and applied to differential current-mode signaling.

Relating localized nanoparticle resonances to an associated antenna problem

We conceptually unify the description of resonances existing at metallic nanoparticles and optical nanowire antennas. To this end the nanoantenna is treated as a Fabry-Perot resonator with arbitrary semi-nanoparticles forming the terminations. We show that the frequencies of the quasi-static dipolar resonances of these nanoparticles coincide with the frequency where the phase of the complex reflection coefficient of the fundamental propagating plasmon polariton mode at the wire termination amounts to $\pi$. The lowest order Fabry-Perot resonance of the optical wire antenna occurs therefore even for a negligible wire length. This approach can be used either to easily calculate resonance frequencies for arbitrarily shaped nanoparticles or for tuning the resonance of nanoantennas by varying their termination.

Electric field induced motion of metallic droplets: Application to submicron contactor

This article reports the monitoring of reversible displacement of a gallium droplet on a tungsten submicron wire deposited by focused ion beam from tungsten hexacarbonyl precursor. The authors demonstrate that by applying a voltage to the wire terminals, the internal electric field created along the wire produces the motion of the droplet. Since the matter involved in this displacement is conductive, the authors show that it is possible to build a submicron electrical switch. Contact can be switched on and off between two electrodes separated by a submicron gap, by electrical monitoring the position of the conductive droplet.

전도냉각형 고온초전도 Wire의 전류도입부에서의 열적 퀜치

The heat generation in the high-<TEX>$T_c$</TEX> superconducting (HTS) wire is related with the cost efficiency and safe factor of HTS devices. This paper deals with the thermal quench at the conduction-cooled joint between HTS wire and copper terminals. The 3-D numerical simulation of thermal distributions in part of the copper terminals was implemented and the premature quench at copper block was observed through the test. The results will be helpful to design the conduction-cooled HTS magnets.

Diffraction of surface plasmon modes on abruptly terminated metallic nanowires

Surface plasmon polariton modes on cylindrical nanowires remain accessible for applications even when the wire radius is only a small fraction of the wavelength. Abrupt wire termination constitutes a basic discontinuity that underlies many of the wire functions. The diffraction of the surface plasmon modes by the discontinuity is investigated. The near field around the termination plane is determined with no simplifying assumptions of the physical aspects of the diffraction process. The transmitted and reflected fields are calculated for wires in vacuum. Full conversion of the surface plasmon mode energy into light is shown to occur at specific values of the wire radius.

大気圧プラズマ表面処理した銅線および銅撚線のフラックス無し鉛フリーはんだメッキ

There has been an intensive effort in the industries in recent years to replace leaded solder with lead-free process in order to minimize the emission of toxic materials. However, leaded solder is still used in many cases where no alternative lead-free process is currently available. Leaded soldering of the wire terminals is one of the worst examples as it causes cross contamination of lead into the lead-free solder bath during the successive process. To avoid this problem, it is important to develop a new process of successfully removing polymer film coated on a copper wire. We have investigated the use of atmospheric pressure plasma as a solution for the polymer removal in conjunction with lead-free solder plating. The atmospheric plasma technology has some unique advantages compared with the conventional low pressure plasma processes such as low cost operation and high speed processing as the chemical reaction tends to be more enhanced at higher pressure. An atmospheric micro-plasma source was thus developed for this purpose and its high etching rate of more than 100 μm/min with fluorine gas mixture was demonstrated. Furthermore, it was found that the copper wires processed by this plasma could be readily plated with lead-free solder at low temperature of 250°C without any use of fluxes even at 168 hours after removing the polymer film.

Interaction of a long molecular wire with a nanostructured surface: Violet Landers on Cu(2 1 1)

Violet Lander molecules (long molecular wires with legs) are deposited on the nanostructured Cu(2 1 1) surface at 325 K and 177 K and investigated by low temperature scanning tunnelling microscopy. Selective population of (3 1 1) steps and local surface restructuring are observed for molecules adsorbed with their axis parallel to intrinsic steps. Thanks to the good matching between molecular dimensions and surface corrugation, molecules oriented perpendicularly to the steps assume conformations which allow tunnelling also through the molecular wire. The molecular wire terminations are hence self-contacted to the Cu(2 1 1) surface native (1 1 1) and (3 1 1) step edges.