Inductive Proximity Sensor Research Articles

Testing and Improvement of Static Performance of Proximity Sensor for a Mobile Robot

In recent years, mobile robot is one of the most interesting topics attracting scientists and factories. With breakthrough techniques in sensor, we can control a mobile robot more reliably. Besides, measuring at static state of the inductive proximity sensor is also necessary since the detective and navigation systems perform more accurately by information from the experiment by analyzing the signal. The purpose of this paper, the hand-made measurement system is used to verify the static performance with the type of aluminium and analyse the relationship between the output signal and the position of the sensor. All we know that the relationship of the static parameters can be determined such as: sensing distance, dimension of material, thickness of material, and so on. The measured data have shown the output signal of proximity sensor in the model and theory which is not identical. The results will provide some information about the different effects of position sensor and optimum operating range of a mobile robot. In addition, by comparing the results achieved, giving solutions to enhance the static performance of the proximity sensor for a mobile robot, such as: choosing of material thickness ranges which is suitable for the operation of a mobile robot, setting the proper sensing distance to be the most stable. This research aims to provide a secure and accurate signal for the control of mobile robots.

Design and Fabrication of Agro-basedAutomatic Plantain Tree Cutting Machine

This paper deals with the design and fabrication of low cost cutting machine for banana tree on a large scale. In existing system, the cutting and decomposition process takes much time and the cost requirement is also high.The mechanical part of the machine consists of lead screw, journal bearing and cutter blade. High strength lead screw is used to eliminate the thrust. The cutter blade is designed to rotate at high speed. The electrical system of the machine contains wiper motor and inductive type proximity sensor. The lead screw coupled with wiper motor rotates in clockwise direction. When proximity sensor detects the top position, signal is sent to the relay and reverses the motor direction. During downward movement cutter blade turned off using multipoint relay. Due to the continuous motion of the cutter blade and lead screw movement, the banana trees are cut into pieces. The machine is designed with economic feasibility by including sensors and relays.

Emulating a robotic manipulator arm with an hybrid motion-control system

A motion control system with four and 1/2 degrees of freedom, designed to move small objects within a 0.25 m3 space, parallel to a horizontal table, with high speed and performance similar to a robotic manipulator arm was built. The machine employs several actuators and control devices. Its main characteristic is to incorporate a servomotor, steeper motors, electromechanical and fluid power actuators and diverse control resources. A group of actuators arranged on a spherical coordinates system is attached to the servomotor platform. A linear pneumatic actuator with an angular grip provides the radial extension and load clamping capacity. Seven inductive proximity sensors and one encoder provide feedback, for operating the actuators under closed loop conditions. Communication between the sensors and control devices is organized by a PLC. A touch screen allows governing the system remotely, easily and interactively, without knowing the specific programming language of each control component. The graphic environment on the touch screen guides the user to design and store control programs, establishing coordinated automatic routines for moving objects in space, simulation and implementation of industrial positioning or machining processes.

Current Collector for Heavy Vehicles on Electrified Roads

We present the adopted motion control schemes of a novel current collector manipulator to be mounted beneath a heavy hybrid electric vehicle to collect electric power from road embedded power lines. We describe our approach of power line detection and tracking based on an array of inductive proximity sensors. The emphasis is on the adopted motion control logic for sequential and closed loop motions to detect and track the power line respectively. We implement the sliding mode control approach for the closed loop control scheme as straightforward solution given the binary nature of the inductive proximity sensors being used. The overall architecture of the entire motion control system is presented. Finally, the implementation of the entire control logic in a form of a state machine is discussed.

A New Inductive Proximity Sensor Based Guiding Tool to Locate Metal Shrapnel During Surgery

Shrapnel injury is a major cause of death in victims of bomb blast, land mines, and gun fire. Currently, doctors rely on imaging systems to locate the shrapnel before surgery. But, since these images do not provide any real-time information of the location of the shrapnel, effectiveness of surgery solely depends on the doctors' skill to trace them. Therefore, in some cases, the shrapnel, in spite of being visible in the images, may become untraceable during surgery. Hence, an online tool that can help the surgeon in finding the location of the shrapnel during the surgery will be very effective. A prototype of such a tool has been realized using an inductive proximity sensor (IPS). The new IPS is small enough for inserting into the victim's body. Since the detection depth (DD) of an IPS decreases with its diameter, this IPS uses a differential sensing scheme for detection. Hence, the new sensor achieves DDs longer than its diameter. The design of the sensor takes care of the effects of parasitic parameters that become predominant as the size gets smaller and ensures repeatable results. The tool also features a special excitation scheme that has multiple advantages when compared with existing schemes. The details of the sensor, its excitation and performance against different targets under various conditions are presented in this paper.

The Disturbance of Inductive Proximity Sensor for Mobile Robot

Non-contactingproximity sensors are widely promoted for position detection through determiningthe distance between sensor and object. Besides, the usage of non-contactinginductive proximity sensors for object detections such as finding non-ferrousand ferrous metal tape is the popular technique in mobile robots. Most of thetechnology uses simple HF- oscillation principle as an inductive proximitysensor (IPS) with a decrease in the quality of the oscillator circuit’selectromagnetic to find the tape. By applying this technique, the externalfactors may cause negative effects to systemperformance. To overcome this situation, we set up a hand measurement withinductive proximity sensors and two tapes, meanwhile main tape and disturbingtape are separated by an obstruction sheet. After measuring, dataresults are used to analyze the influence of the obstruction sheet thickness anddisturbance tape to the noise in received signals. The research isthe fundament for further applications, based on inductive proximity sensor formobile robot that could be more robust against noises and disturbances.

Development of a proximity sensor with vertically monolithic integrated inductive and capacitive sensing units

This study designs and implements a proximity sensor consisting of inductive and capacitive sensing units. These two sensing units are vertically monolithic integrated on a single chip using the micro-fabrication processes. In addition, low-temperature fabricated nanoporous anodic aluminum oxide (np-AAO) is employed as the dielectric layer to enhance the performance of capacitive sensing. The characteristics of the presented vertically monolithic integrated inductive and capacitive proximity sensor are as follows: (1) enlarged sensing distance of conductive objectives: capacitive sensing unit for short distance detection and inductive sensing unit for long distance detection, (2) non-conductive object can be detected by the capacitive sensing unit, (3) fringe effect capacitive sensing is enhanced by the spiral coil electrode and (4) np-AAO has good dielectric properties (the dielectric constant is 11.9 in this study) for capacitive sensing. In application, various materials (including metal, plastic and a human finger) have been successfully detected by the presented sensor. Preliminary results demonstrate that the typical fabricated proximity sensor has a sensing range of 0.5–5 mm for the metal rod. In comparison, the inductive and capacitive sensing units have the sensing ranges of 1.5–5 and 0.5–3 mm, respectively. Moreover, the non-conductive plastic rod can be detected by the capacitive sensing unit.

Design of a LabVIEW System Applied to Predictive Maintenance

The implementation of vibration analysis techniques based on virtual instrumentation has spread increasingly in the academic and industrial branch, since the use of any software for this type of analysis brings good results at low cost. Among the existing software for programming and creation of virtual instruments, the LabVIEW was chosen for this project. This software has good interface with the method of graphical programming. In this project, it was developed a system of rotating machine condition monitoring. This monitoring system is applied in a test stand, simulating large scale applications, such as in hydroelectric, nuclear and oil exploration companies. It was initially used a test stand, where an instrumentation for data acquisition was inserted, composed of accelerometers and inductive proximity sensors. The data collection system was structured on the basis of an NI 6008 A/D converter of National Instruments. An electronic circuit command was developed through the A/D converter for a remote firing of the test stand. The equipment monitoring is performed through the data collected from the sensors. The vibration signals collected by accelerometers are processed in the time domain and frequency. Also, proximity probes were used for the axis orbit evaluation and an inductive sensor for the rotation and trigger measurement.

A LTCC low-loss inductive proximity sensor for harsh environments

Proximity and position measurements with eddy current sensors are limited by the quality factor of the sensing coils. By enlarging the conductor path cross section, the quality factor can be increased. On ceramic multilayer substrates such cross sections, which are considerably larger in comparison to screen printed thick films, can be manufactured with an embossing and filling procedure, which is integrated into the conventional fabrication process. The conductor path layout is molded into the unfired ceramic substrate prior to filling the trenches completely with the conducting paste, thus generating a large cross section. This technique is applied for the sensing coil of an eddy current sensor. The higher quality factor leads to a doubled sensitivity in comparison to conventionally screen printed sensors. Due to the thermal and chemical durability of the ceramic substrate, the coils can be directly applied in a variety of harsh environment conditions, such as in situ engine monitoring.

NOTA TÉCNICA: DESENVOLVIMENTO DE DISPOSITIVO ELETRÔNICO PARA MARCAÇÃO AUTOMÁTICA DO PONTO DE TRAÇAMENTO DA MADEIRA POR UMA GARRA TRAÇADORA

Este trabalho foi conduzido em povoamentos de eucalipto de uma empresa florestal do Estado de Goiás, com o objetivo de desenvolver dispositivo eletrônico para marcação automática do ponto de traçamento da madeira. O trator utilizado neste trabalho foi uma escavadora hidráulica, modelo 320 CL, fabricante caterpillar, com 103 kW de potência nominal do motor. Para o controle do ponto de traçamento dos toretes, foram utilizados um contador
 controlador programável, um gerador de pulsos e um sensor de proximidade do tipo indutivo. De acordo com os resultados, conclui-se que os valores encontrados para os comprimentos dos toretes quando medidos pelo dispositivo eletrônico e pela tora padrão ficaram próximos do desejado. O sensor utilizado não foi capaz de zerar automaticamente os valores quando o operador ultrapassou a medida desejada. O dispositivo ainda necessita de ajustes principalmente quanto ao tempo de traçamento.

비접촉 진동 검출을 위한 유도성 근접센서모듈 개발

금속물체의 피로도를 측정하기 위하여 고속으로 진동시키면서 비접촉으로 정밀하게 변위를 측정하는 방법에 대한 연구가 많이 이루어지고 있다. 비접촉 고속 진동 검출센서들은 와류 센서나 레이저 센서들을 주로 사용하고있지만 매우 고가이다. 최근 저가의 유도성 센서를 고속 진동검출에 적용하려는 연구가 이루어지고 있으나 아직은 초보단계이다. 본 연구에서는 저가의 유도성 센서를 이용하여 비접촉으로 고속 진동을 검출하는 새로운 근접 센서모듈 설계방법을 제안하였다. 기존의 유도성 센서모듈들은 검파, 적분, 및 증폭과정을 통하여 변위를 검출하기 때문에 아날로그회로 특성상 잡음에 약하고 적분과정에서 변위 검출속도 저하의 요인이 된다. 제안된 방법은 AD변환기(Analog to Digital converter)를 사용하지 않고 진동 주파수신호를 직접 디지털 신호로 변환하는 새로운 방법으로 아날로그 잡음의 영향을 적게 받으며 고속으로 신호를 처리할 수 있는 장점이 있다. 성능 평가를 위하여 셰이커로 진동 주파수를 30Hz부터 1,100Hz 까지 일정간격으로 금속편을 진동시키면서 제안된 센서 모듈을 이용하여 비접촉으로 진동 신호를 검출하였다. 실험결과 비접촉 근접 거리 5mm 이내에서 진동 주파수 검출범위는 DC에서 1,100Hz까지 측정할 수 있었으며 진동 폭의 해상도는 <TEX>$20{\mu}m$</TEX>로 나타났다. 따라서 제안된 유도성 센서모듈은 정밀 비접촉 고속 진동검출 센서로서 충분한 성능을 가지고 있다고 평가된다. To measure the fatigue of metallic objects at high speed vibration while non-contact precision displacement measurement on how to have a lot of research conducted. Noncontact high-speed vibration detection sensor of the eddy current sensors and laser sensors are used, but it is very expensive. Recently, High-speed vibrations detection using an inexpensive inductive sensor to have been studied, but is still a beginner. In this paper, a new design of an inexpensive inductive proximity sensor has been suggested in order to measure high frequency dynamic displacements of metallic specimens in a noncontact manner. Detection of the existing inductive sensors, detection, integral, and amplified through a process to detect the displacement noise due to weak nature of analog circuits and integral factor in the process of displacement detection is slow. The proposed method could be less affected by noise, the analog receive and high-speed signal processing is a new way, because AD converter (Analog to Digital converter) without using the vibration frequency signals directly into digital signals are converted. In order to evaluate the sensing performance, The proposed sensor module using non-contact vibration signals were detected while shaker vibration frequencies from 30Hz to 1,100 Hz at intervals of vibrating metallic specimens. Experimental results, Vibration frequency detection range of the metallic specimins within close proximity to contactless 5mm could be measured from DC to 1,100Hz and vibration amplitude of the resolution was <TEX>$20{\mu}m$</TEX>. Therefore, the proposed non-contact inductive sensor module for precision vibration detection sensor is estimated to have sufficient performance.

Measurement of Material Flow in Series Production

This paper provides first results of a contact-free measurement system for monitoring the material flow in series production which has been under investigation for more than one year. An inductive proximity sensor with analog output was used to measure its own sheet metal coverage. Multiple sensors were integrated in the blank holder without affecting the deep drawing process. The robustness of the monitoring principle was assessed under series production conditions by using optical measurement equipment. This paper describes the basic information of the inductive measurement, the comparison of the inductive and optical measurement results and analyses correlations between the sensors.

Inductive Proximity Sensor with Novel Structure of Ferrite Core

Inductive proximity sensors (proximity sensors) are noncontact sensing devices used to detect the approach of a target by an increase in coil impedance due to eddy current loss. Extending the operating distance of these sensors is demanded. The flux of a conventional proximity sensor has difficulty in reaching the target because of the presence of the center magnetic pole of ferrite core. Therefore, in this paper, we examine a proximity sensor using a novel structure of ferrite core without the center magnetic pole. In this novel structure, flux easily reaches the target because of the absence of the center magnetic pole. In addition, it is possible to reduce AC resistance due to the proximity effect for the use of a magnetoplated wire. As a result, the operating distance for the novel structure is 1.3-fold that for the conventional structure.

Theoretical control and experimental verification of a calender roller system part I: dynamic system modeling and model predictive controller design

The objective of this study is to deal with the control of the pressed roller to get high quality of the calendering products. First, the pressed roller is assumed as an Euler-Bernoulli beam and the forces which are produced by the pressing roller are considered as distributed forces. The mathematical model of the system is derived as a continuous system using Hamilton’s principle, Lagrange’s equations and assumed-modes method. Originally, the achieved model is a two-input with one-output system. Since the distributed forces are constants, the model can be simplified to a single-input single-output system by changing variables. An advanced control technique, Model Predictive Control (MPC), is used and a state estimator is designed in order to set up a realizable control system. The control system is implemented for experimental verification as well. It includes pressed and pressing rollers, a personal computer with VisSim software, RT-DAC4/PCI card, inductive proximity sensor and electro-hydraulic actuator. The performance of the proposed control system can be shown through a real implementation.

Extending the Operating Distance of Inductive Proximity Sensor Using Magnetoplated Wire

Inductive proximity sensors are noncontact sensing devices used to detect the approach of a target by an increase in coil resistance due to eddy current loss. Extending the operating distance of these sensors is demanded. In this paper, we propose the use of a magnetoplated wire (MPW) as a sensing coil. The MPW is a copper wire, whose circumference is plated with a magnetic thin film. We analyze the impedance of a proximity sensor using a copper wire (COW) and MPW coils by a finite element method. The use of the MPW results in a decrease in AC resistance due to the proximity effect, an increase in inductance, and the generation of a higher flux than when the COW is used. Therefore, it is possible to increase the quality factor Q of the MPW coil. As a result, the operating distances of the MPW and COW coils are 5.0 and 3.8 mm, respectively. The operating distance of the MPW coil is 1.3-fold that of the COW coil.

Development and validation of a novel bioreactor system for load‐ and perfusion‐controlled tissue engineering of chondrocyte‐constructs

Osteoarthritis is a severe socio-economical disease, for which a suitable treatment modality does not exist. Tissue engineering of cartilage transplants is the most promising method to treat focal cartilage defects. However, current culturing procedures do not yet meet the requirements for clinical implementation. This article presents a novel bioreactor device for the functional tissue engineering of articular cartilage which enables cyclic mechanical loading combined with medium perfusion over long periods of time, under controlled cultivation and stimulation conditions whilst ensuring system sterility. The closed bioreactor consists of a small, perfused, autoclavable, twin chamber culture device with a contactless actuator for mechanical loading. Uni-axial loading is guided by externally applied magnetic fields with real-time feedback-control from a platform load cell and an inductive proximity sensor. This precise measurement allows the development of the mechanical properties of the cultured tissue to be monitored in real-time. This is an essential step towards clinical implementation, as it allows accounting for differences in the culture procedure induced by patient-variability. This article describes, based on standard agarose hydrogels of 3 mm height and 10 mm diameter, the technical concept, implementation, scalability, reproducibility, precision, and the calibration procedures of the whole bioreactor instrument. Particular attention is given to the contactless loading system by which chondrocyte scaffolds can be compressed at defined loading frequencies and magnitudes, whilst maintaining an aseptic cultivation procedure. In a "proof of principle" experiment, chondrocyte seeded agarose gels were cultured for 21 days in the bioreactor system. Intermittent medium perfusion at a steady flow rate (0.5 mL/min) was applied. Sterility and cell viability (ds-DNA quantification and fluorometric live/dead staining) were preserved in the system. Flow induced shear stress stimulated sGAG (sulfated glycosaminoglycan) content (DMMB assay) after 21 days, which was confirmed by histological staining of Alcian blue and by immunostaining of Aggrecan. Experimental data on mechanotransduction and long-term studies on the beneficial effects of combined perfusion and different mechanical loading patterns on chondrocyte seeded scaffolds will be published separately.

New Noncontacting Inductive Analog Proximity and Inductive Linear Displacement Sensors for Industrial Automation

Noncontacting inductive sensors are applicable on a large scale for position detection or travel measurement in industrial applications. Reasons for such broad acceptance in many sectors of industry are noncontact and wear-free sensing of the target (any metal object), reliability and robustness, resistance to fouling, water tightness and compact size. The present work is intended to be a systematic, complete, and consistent presentation of the technological innovations, recent implementations and current trends regarding the analog distance and travel sensing offered by noncontacting inductive sensors for industrial applications. It starts with the fundamentals of inductive sensing and presents the physical basics gained by modern analytic and simulation methods, as well as high-level integrated circuits for inductive sensors. The following sections deal with present-day inductive analog proximity sensors and with the distinctive technological innovation offered by the new inductive linear displacement sensors and with miniaturization results achieved through consistent integration.

Progress and Recent Realizations of Miniaturized Inductive Proximity Sensors for Automation

Noncontacting inductive proximity sensors (IPSs) are widely preferred for position detection in industrial applications. Advances in computer-aided design simulation tools, integration, and assembly techniques for the last ten years have made possible continued sensor-feature improvements in parallel to size reduction toward very small miniaturized versions. This paper refers to the progress in the past years, presenting recently gained knowledge in sensing principle, evaluation electronics, and manufacturing. The most significant improvements are the usage of a drum-core topology, application-specified integrated circuit implementation, and face-down flip-chip technology. The fundamentals shown in this paper were essential for the design and development of a worldwide innovation: the smallest single-component IPS family that has the largest switching distance. Mounted in a stainless steel tube with a diameter of only 3 mm and a length of 33 mm, the smallest sensor in the family is able to detect metal targets at distances of up to 3 mm and provide an output switching signal with high-current capacity

The flexure-based microgap rheometer (FMR)

We describe the design and construction of a new microrheometer designed to facilitate the viscometric study of complex fluids with very small sample volumes (1–10μl) and gaps of micrometer dimensions. The flexure-based microgap rheometer (FMR) is a shear-rate-controlled device capable of measuring the shear stress in a plane Couette configuration with directly controlled gaps between 1 and 200μm. White light interferometry and a three-point nanopositioning stage using piezo-stepping motors are used to control the parallelism of the upper and lower shearing surfaces, which are constructed from glass optical flats. A compound flexure system is used to hold the fluid sample testing unit between a drive spring connected to an “inchworm” motor and an independent sensor spring. Displacements in the sensing flexure are detected using an inductive proximity sensor. Ready optical access to the transparent shearing surfaces enables monitoring of the structural evolution in the gap with a long working-distance video microscope. This configuration then allows us to determine the microgap-dependent flow behavior of complex fluids over 5 decades of shear rate. We demonstrate the capability of the FMR by characterizing the complex stress and gap-dependent flow behavior of a typical microstructured food product (mayonnaise) over the range of gaps from 8to100μm and stresses from 10to1500Pa. We correlate the gap-dependent rheological response to the microstructure of the emulsion and changes induced in the material by prolonged shearing.

A low-cost inductive proximity sensor for industrial applications

In this paper,we present an inductive proximity sensor with fully integrated electronics. The sensor with the compact hybrid configuration is composed of a sensing flat coil and an integrated electronic interface. We focused during the development on the temperature stability and robustness of the sensor by keeping its low-fabrication cost. The sensor exhibits a longitudinal resolution of 120 nm for an aluminum target position up to 500um from the sensing coil with the side size of 3.5 mm. The temperature drift of the sensor is less than 700 ppm/◦C for the same range of the target position. The total working range is from 100 to 1500um. The sensor power consumption is 100mW and the active sensor dimensions are 3.5mm×3.5mm×1.2 mm.We also showed the facility of the sensor packaging. This kind of integrated sensor has the potential for even more industrial applications.