A Noncontact Angle Sensor Based on Eddy Current Technique
01 Apr 2020-IEEE Transactions on Instrumentation and Measurement (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 69, Iss: 4, pp 1275-1283
TL;DR: This paper presents the design and development of a novel, linear, eddy current-based noncontact angle sensor with 360° range that has no electrical contact to the rotary part and its output is immune to moisture, dust, and oil.
Abstract: This paper presents the design and development of a novel, linear, eddy current-based noncontact angle sensor with 360° range. Although the eddy current proximity sensors are known for high reliability, resolution, and insensitivity to moisture and oil, the approach has not been exploited to develop full-circle range angle sensors with such features. The proposed sensor consists of a rotary conducive hollow tube (e.g., made of aluminum) part and a stationary part with four identical flexible coils. The tube has a simple but special groove. The position of the groove modifies the value of the inductance of the stationary coil as a function of the sensing angle. The design is such that the inductance of each coil varies linearly for a specified range of the angle. From this piecewise linear characteristic, an output that is linear for the full-circle range is obtained using a simple yet effective algorithm. A suitable signal conditioning circuit is developed to obtain an output that is proportional to the change in the inductance of the coil. In order to optimize the design, first, the sensor structure was studied using finite-element analysis. Then, a prototype of the sensor was built and tested in the laboratory. The prototype sensor has a resolution of 0.08° and a maximum nonlinearity of 0.25%. The possible sources of error of the sensor have been analyzed and quantified. The sensor has no electrical contact to the rotary part and its output is immune to moisture, dust, and oil.
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25 May 2020
TL;DR: A signal conditioning circuit is presented in this paper which measures the difference in inductance between two coils and a suitable algorithm has been developed to calculate the displacement using the corresponding inductance values.
Abstract: This paper presents a novel, non-contact displacement sensor based on the eddy current sensing technique. The moving part of the sensor is a conductive sheet with a simple surface groove. This part is easy to fabricate as the machining process required is simple. The moving part is not electrically connected to the measurement system, like the eddy current proximity sensor. The displacement of the moving part is determined by the change in the inductance of four identical stationary planar coils kept underneath the moving part. A signal conditioning circuit is presented in this paper which measures the difference in inductance between two coils. A suitable algorithm has been developed to calculate the displacement using the corresponding inductance values. A prototype has been fabricated in the laboratory to evaluate the performance. The test result shows that the maximum error is less than 1.65%. The output of the prototype sensor was linear for the full range, as expected. It is well suited for application where the vertical space available for the installation is limited. The overall thickness of the developed sensor is less than 5 mm.
5 citations
Cites background or methods from "A Noncontact Angle Sensor Based on ..."
...A non-contact angular displacement sensor based on eddy current technique has been reported in [15]....
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...It uses a conductive moving part with a simple surface groove and does not require a through-hole groove like the one in [15]....
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TL;DR: In this article, a simple and efficient sensing mechanism, using tunneling magnetoresistance (TMR) sensors and a measurement scheme is presented to enable the primary pad to automatically detect and identify the secondary pad in an electric vehicle (EV).
Abstract: In this article, a simple and efficient sensing mechanism, using tunneling magnetoresistance (TMR) sensors and a measurement scheme is presented to enable the primary pad to automatically detect and identify the secondary pad in an electric vehicle (EV). In wirelessly charged EVs, a primary pad that can interoperate with different types of secondary pads is highly beneficial. A bipolar pad (BPP) primary can be configured to transfer power to a circular pad (CP) or a double-D pad (DDP) secondary. In the proposed system, during the sensing phase, the primary pad is excited at a very low current ( $k$ ) is clearly observed. This reduces the primary current considerably. In addition, the magnitude of the primary magnetic field is modulated/changed due to the magnetic field of the secondary. When a DDP secondary is present above the primary, a slight yet repeatable change is seen in the primary magnetic field due to the modulation, while the frequency bifurcation is not seen as the $k$ is very low. The simulation and experimental studies show that these features can be used to reliably detect and identify the type of secondary pad. In the prototype developed, TMR sensors are integrated at the optimal locations on the primary pad to sense the change in the magnetic flux density. In addition, the prototype pad and sensor system developed distinguishes between the metallic body and the secondary pad so that an accidental turning on of the primary pad can be avoided. The results, from the laboratory prototype built and tested in detail, validate the functionality and usefulness of the proposed scheme.
5 citations
TL;DR: In this article , a reflective-type fiber sensor allowing simultaneous measurements of directional torsion, strain, and temperature is proposed and experimentally demonstrated, which is realized by using a paired helical long-period fiber gratings and a trapezoid-like microcavity (PHLPGs-TLMC).
Abstract: A reflective-type fiber sensor allowing the simultaneous measurements of directional torsion, strain, and temperature is proposed and experimentally demonstrated, which is realized by using a paired helical long-period fiber gratings and a trapezoid-like microcavity (PHLPGs-TLMC). With aid of the proposed sensor, the crosstalk effects among torsion, strain, and temperature can be well distinguished. The measurement resolutions for such three parameters are 0.017 rad/m, $2.1~\mu \varepsilon $ , and $0.452~^{\circ }\text{C}$ , respectively, which are competitive to those of the fiber-based sensors. In comparison with the transmission-type sensors reported to date, the proposed sensor is particularly used in reflection, which provides more flexibilities for sensor’s installation and is suitable for real-time and in-site measurements also. The proposed sensor could be found potential applications in structural health monitoring of the buildings, the bridges, the ships, the aircrafts, and so on.
3 citations
TL;DR: In an automated steering system of the self-driving vehicles, the steering wheel angle is measured by the absolute angular displacement sensors or relative angle sensors as discussed by the authors, however, these sensors eit
Abstract: In an automated steering system of the self-driving vehicles, the steering wheel angle is measured by the absolute angular displacement sensors or relative angle sensors. However, these sensors eit...
3 citations
TL;DR: An optical angle sensor based on the collimated mode-locked femtosecond laser (Fs) beam, in which the angle measurement is carried out by observing the second harmonic wave generated by irradiating the Fs beam towards MgO:LiNbO3 crystal, is proposed in this article .
Abstract: An optical angle sensor based on the collimated mode-locked femtosecond laser (Fs) beam, in which the angle measurement is carried out by observing the second harmonic wave generated by irradiating the Fs beam towards MgO:LiNbO3 crystal, is proposed. The angle detection is demonstrated by identifying the second harmonic generation (SHG) spectrum peaks against the angular position of the rotating stage-mounted MgO:LiNbO3 crystal that represents the measurement object. The MgO:LiNbO3 with a length of 2 mm, a cut-off angle of 47°, a diameter of 5 mm, and 5% of MgO:LN, is rotated within the phase-matching angle over a wavelength range from 1480 nm to 1640 nm. Angle measurement is also carried out by placing the crystal at different positions along the laser beam propagation direction to confirm the feasibility of the angle sensor where the measurement range, measurement sensitivity, and resolution of the proposed method are also evaluated. The result shows that the proposed angle sensor can overcome the working distance limitation of conventional angle sensors and has no specific material target requirement. Since the configuration of the proposed angle sensor is not limited by the specification of the measurement target, it is expected to have wide potential applications, especially in the manufacturing process and inspection process.
2 citations
References
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Book•
01 Jan 1988TL;DR: In this article, the authors present a design-oriented course for operational amplifiers and analog ICs, which includes additional problems, more in-depth coverage of negative feedback, more effective layout, updated technology (current feedback and folded-cascode amplifiers, and low-voltage amplifiers), and increased topical coverage (current-feedback amplifier, switching regulators and phase-locked loops).
Abstract: Franco's "Design with Operational Amplifiers and Analog Integrated Circuits, 3e" is intended for a design-oriented course in applications with operational amplifiers and analog ICs. It also serves as a comprehensive reference for practicing engineers.
This new edition includes enhanced pedagogy (additional problems, more in-depth coverage of negative feedback, more effective layout), updated technology (current-feedback and folded-cascode amplifiers, and low-voltage amplifiers), and increased topical coverage (current-feedback amplifiers, switching regulators and phase-locked loops).
Table of contents
1 Operational Amplifier Fundamentals
2 Circuits with Resistive Feedback
3 Active Filters: Part I
4 Active Filters: Part II
5 Static Op Amp Limitations
6 Dynamic Op Amp Limitations
7 Noise
8 Stability
9 Nonlinear Circuits
10 Signal Generators
11 Voltage References and Regulators
12 D-A and A-D Converters
13 Nonlinear Amplifiers and Phase-Locked Loops
696 citations
"A Noncontact Angle Sensor Based on ..." refers methods in this paper
...A Howland current source [33] was realized using an op-amp LF347....
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TL;DR: An up-to-date review paper on automotive sensors is presented in this article, where the primary sensor technologies in use today are reviewed and classified according to their three major areas of automotive systems application-powertrain, chassis, and body.
Abstract: An up-to-date review paper on automotive sensors is presented. Attention is focused on sensors used in production automotive systems. The primary sensor technologies in use today are reviewed and are classified according to their three major areas of automotive systems application-powertrain, chassis, and body. This subject is extensive. As described in this paper, for use in automotive systems, there are six types of rotational motion sensors, four types of pressure sensors, five types of position sensors, and three types of temperature sensors. Additionally, two types of mass air flow sensors, five types of exhaust gas oxygen sensors, one type of engine knock sensor, four types of linear acceleration sensors, four types of angular-rate sensors, four types of occupant comfort/convenience sensors, two types of near-distance obstacle detection sensors, four types of far-distance obstacle detection sensors, and and ten types of emerging, state-of the-art, sensor technologies are identified.
476 citations
"A Noncontact Angle Sensor Based on ..." refers methods in this paper
...The automotive applications include steering angle sensor, rotary switches, throttle angle, and accelerator pedal position sensors [1]....
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Book•
17 Aug 1993
TL;DR: Signal Conditioning for Resistive Sensors Reactance Variation and Electromagnetic Sensors and Signals for Self-Generating Sensors Signal conditioning for self-Generation Sensors Digital Sensors Telemetry and Data Acquisition.
Abstract: Resistive Sensors Signal Conditioning for Resistive Sensors Reactance Variation and Electromagnetic Sensors Signal Conditioning for Reactance Variation Sensors Generating Sensors Signal Conditioning for Self-Generating Sensors Digital Sensors Other Sensing Methods Telemetry and Data Acquisition General Bibliography Appendix Index.
432 citations
TL;DR: In this paper, the authors take up the challenge of making a sensor work in a measurement system by providing excitation, if required, and then performing the preliminary actions needed to obtain a signal that can be processed.
Abstract: The challenge we take up in this fourth installment in a series of tutorials in instrumentation and measurement is to consider how to make a sensor work in a measurement system. Signal conditioning broadly includes the steps needed to make the sensor an active part of a measurement system by providing excitation, if required, and then performing the preliminary actions needed to obtain a signal that can be processed. What's done to and with that signal is the subject of future parts of this tutorial series. Luckily, we don't have to wait that long to get results, because the output of the signal conditioning stage can be used for something as simple as driving a display subsystem so that we see results. Signal conditioning is a critical step in a measurement system but so is each element as emphasized by the serial model we have been using so far to depict the basic elements of an instrument. However, it is important to keep in mind that many overall performance limits of a measurement are strongly influenced by what happens in the signal conditioning stage. For example, linearity, accuracy, noise rejection, and long-term drift behaviors will be strongly affected by decisions made here.
132 citations
"A Noncontact Angle Sensor Based on ..." refers background or methods in this paper
...As the final output is obtained using a PSD, the interference signals induced in the coil will have a very low effect in the output [14]....
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...In this paper, the PSD is implemented in the virtual instrument using LabVIEW....
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...The output voltage vG (t) = √ 2 GVRE sin(ω t) of the amplifier G is used as the reference signal for the PSD, where VRE is the voltage across the external resistance RE ....
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...the phase difference between VA and VRE can be measured using a switching-type phase sensitive detector (PSD) [14] as given in Fig....
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...In order to find the suitable G, instead of measuring Req and RE , the phase difference between VA and VRE can be measured using a switching-type phase sensitive detector (PSD) [14] as given in Fig....
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29 Jan 2014
TL;DR: The second edition of the bestselling Measurement, Instrumentation, and Sensors Handbook as discussed by the authors brings together all aspects of the design and implementation of measurement, instrumentation and sensors, including processing systems, automatic data acquisition, reduction and analysis, operation characteristics, accuracy, errors, calibrations, and the incorporation of standards for control purposes.
Abstract: The Second Edition of the bestselling Measurement, Instrumentation, and Sensors Handbook brings together all aspects of the design and implementation of measurement, instrumentation, and sensors. Reflecting the current state of the art, it describes the use of instruments and techniques for performing practical measurements in engineering, physics, chemistry, and the life sciences and discusses processing systems, automatic data acquisition, reduction and analysis, operation characteristics, accuracy, errors, calibrations, and the incorporation of standards for control purposes.
Organized according to measurement problem, the Spatial, Mechanical, Thermal, and Radiation Measurement volume of the Second Edition:
Contains contributions from field experts, new chapters, and updates to all 96 existing chapters
Covers instrumentation and measurement concepts, spatial and mechanical variables, displacement, acoustics, flow and spot velocity, radiation, wireless sensors and instrumentation, and control and human factors
A concise and useful reference for engineers, scientists, academic faculty, students, designers, managers, and industry professionals involved in instrumentation and measurement research and development, Measurement, Instrumentation, and Sensors Handbook, Second Edition: Spatial, Mechanical, Thermal, and Radiation Measurement provides readers with a greater understanding of advanced applications.
105 citations
"A Noncontact Angle Sensor Based on ..." refers background in this paper
...The conventional rotary potentiometers [3] (resistive) require a spring-loaded wiper contact....
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