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Magnetic angular encoder using an offset compensation technique

IEEE SENSORS JOURNAL 2004年第6期4卷 759-763页

作者： Kayal, M Burger, F Popovic, RS Swiss Fed Inst Technol EPFL IMM CH-1015 Lausanne Switzerland

Quality and resolution of integrated microsystems using Hall sensors dedicated to an angular encoder are strongly dependent on the accuracy of the relative position of Hall sensors and on the offset of electronic front end circuitry. In this paper, we describe a CMOS microsystem built on two integrated circuits. This contactless encoder microsystem gives three sine and square signals with a phase shift of 120degrees and provides an angular error of less than 4degrees without external trimming or feedback. The Hall sensor assembly with the engine consists of fixing a small permanent magnet on the rear axis of the motor. Then, the sensor is positioned in front of this magnet.

关键词： angular encoder autozero CMOS Hall sensor microsystem offset cancellation

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A novel laser Doppler linear encoder using multiple-reflection optical design for high-resolution linear actuator

A novel laser Doppler linear encoder using multiple-reflecti...

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Conference on Current Developments in Optical Design and Engineering VII

作者： Shu, DM Alp, EE Barraza, J Kuzay, TM Mooney, TM Argonne Natl Lab Expt Facil Div Adv Photon Source Argonne IL 60439 USA

ISBN: (纸本)0819428841

A novel laser Doppler linear encoder system (LDLE) has been developed at the Advanced Photon Source, Argonne National Laboratory A self-aligning 3-D multiple-reflection optical design was used for the laser Doppler displacement meter (LDDM) to extend the encoder system resolution. The encoder is compact [about 70 mm(H) x 100 mm(W) x 250 mm(L)] and it has sub-Angstrom resolution 100 mm/sec measuring speed, and 300 mm measuring range. Because the new device affords higher resolution, as compared with commercial laser interferometer systems, and yet cost less, it will have good potential for use in scientific and industrial applications.

关键词： linear encoder angular encoder laser encoder high resolution actuator

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Combustion Characteristics of Diesohol Using Biodiesel as an Additive in a Direct Injection Compression Ignition Engine under Various Compression Ratios

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ENERGY & FUELS 2009年第11期23卷 5413-5422页

作者： Selvan, V. Arul Mozhi Anand, R. B. Udayakumar, M. Natl Inst Technol Dept Mech Engn Tiruchirappalli India

An experimental investigation is carried out to study the combustion characteristics of diesel-biodiesel-ethanol blends in a single-cylinder four stroke direct injection variable compression ratio engine under the compression ratios 15:1, 17:1, and 19:1. As the ethanol is immiscible with diesel, biodiesel (jatropha methyl, ester) is used as an additive to prevent the phase separation of the diesel-ethanol blends. The addition of ethanol decreases the cetane number of the blend, whereas the biodiesel addition improves the cetane number of the resultant mixture. The combustion characteristics of the stable fuel blends (D85B10E5, D80B10E10, D75B10E15, D70B10E20, and D65B10E25) are studied and compared with neat diesel by conducting experiments on the computerized variable compression ratio engine test rig. A piezoelectric pressure sensor and a crank angle encoder are used to record the cylinder gas pressure and a crank angle, respectively, to determine the combustion parameters. It is observed that the cylinder gas pressure, maximum rate of pressure rise, and heat release rate increase with higher ethanol concentration due to the longer ignition delay. Also it is found that the ignition delay decreases with the increase in compression ratio and brake mean effective pressure. The total combustion duration is longer as the total fuel consumption is higher for the diesel-biodiesel-ethanol blends than neat diesel. The exhaust gas temperature is found lower for the diesel-biodiesel-ethanol blends. The relative air fuel ratio is found higher for the diesel-biodiesel-ethanol blends than neat diesel and decreases with an increase ill brake mean effective pressure. This research work established an insight oil the fuel burning characteristics or the diesel-biodiesel-ethanol blends under various compression ratios and loading conditions.

关键词： CA: crank angle CR: compression ratio BP: brake power bmep: brake mean effective pressure λ: relative air-fuel ratio et al compression ratio Combustion biodiesel Cetane number Air fuel ratio IGNITION ENGINES exhaust gas temperature Additives Ignition delay Variable compression ratio engines Compressed gases Blends Diesel Fuel angular encoder Phase separation

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Automatic calibration of Hall sensor microsystems

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MICROELECTRONICS JOURNAL 2006年第12期37卷 1569-1575页

作者： Kayal, M. Pastre, M. Ecole Polytech Fed Lausanne Elect Lab STI IMM LEG CH-1015 Lausanne Switzerland

In many applications, a Hall element is used for contact-less measurement such as linear and angular positions, electrical current, power and energy, etc. The Hall element fabricated by means of CMOS technology features mediocre characteristics [R.S. Popovic, Z. Randjelovic, D. Manic, Integrated Hall-Effect Magnetic Sensors, EMSA, Germany, 2000;R.S. Popovic, Hall Effect Devices, Adam Hilger, Bristol, Philadelphia, New York, 1991]. It gives a weak output signal of the order of a few mV. This signal is often corrupted by sensor offset, noise, temperature and aging drift. This paper deals with the state of the art and main techniques capable to detect and compensate these issues. Case studies using mentioned techniques are also summarized. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： CMOS Hall sensor offset cancellation auto-zero current sensor microsystem angular encoder

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Application of diffractive optical elements in laser metrology

Application of diffractive optical elements in laser metrolo...

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7th International Symposium on Laser Metrology Applied to Science, Industry and Everyday Life

作者： Poleshchuk, AG Koronkevich, VP Korolkov, VP Sedukhin, AG Russian Acad Sci Siberian Branch Inst Automat & Electrometry Novosibirsk 630090 Russia

ISBN: (纸本)0819446866

Laser metrology often requires the precision forming of a probe laser beam with necessary wavefront shape or given intensity distribution. This problem is solved optimally by application. of diffractive optical elements (DOE). In the IA&E SB RAS a circular laser writing system (CLWS) was created for high precision DOE fabrication. This system allows to fabricate arbitrary DOEs with minimum feature sizes below 0.6 mum and the radial position accuracy of about 0.1 mum over 300 min substrates. The investigations carried out have confirmed promising prospects of application of high precision DOEs fabricated with the help of CLWS for solving various metrological problems.

关键词： diffractive optical elements optical testing circular laser writing system angular encoder interferometers

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A linear actuator system with 1-angstrom closed-loop control resolution and 50-milimeter travel range

A linear actuator system with 1-angstrom closed-loop control...

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Conference on Optomechanical Design and Engineering

作者： Shu, DM Han, YF Toellner, TS Alp, EE Argonne Natl Lab Adv Photon Source Argonne IL 60439 USA

ISBN: (纸本)081944538X

We have designed and tested a novel linear actuator system with 1-angstrom closed-loop control resolution and 50-mm. travel range. There are two major ultraprecision motion control techniques that have been applied to this actuator: A novel laser Doppler encoder system with multiple-reflection optics. A specially designed high-stiffness weak-link mechanism with stacked thin metal sheets having sub-angstrom driving sensitivity with excellent stability. In this paper, we present the system design and test results of this linear actuator. Applications of this new actuator system are also discussed.

关键词： linear encoder angular encoder laser encoder high resolution actuator

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Fabrication and application of diffractive optical elements

Fabrication and application of diffractive optical elements

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6th International Symposium on Precision Engineering Measurements and Instrumentation

作者： Poleshchuk, A. G. Inst Automat & Electrometry SB RAS Novosibirsk 630090 Russia

ISBN: (纸本)9780819479402

The fabrication methods of binary and continuous-relief diffractive optical elements (DOE) by direct laser writing and lithography are analyzed. Laser metrology often requires the precision forming of a probe laser beam. This problem is solved optimally by application of DOEs. A number of scientific and practical applications require the fabrication of DOEs to create highly accurate aspherical wavefronts. This paper reviews the research directed toward the creation of equipment and technologies for DOEs with a binary, multilevel, and continuous profile. The results of the practical applications of DOEs (fabricated in Institute of Automation and Electrometry SB RAS) in optical measuring systems are presented.

关键词： Diffractive optical elements optical testing circular laser writing system angular encoder interferometers

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Laser beam optical focusing method for measurement of angular sensor glass scale quality parameters

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JOURNAL OF VIBROENGINEERING 2012年第1期14卷 157-164页

作者： Juska, V. Vastakas, E. Ibenskis, E. Kaunas Univ Technol LT-54124 Kaunas Lithuania

This paper introduces alternative to existing, glass scale quality parameters measurement method based on optical focusing, which is used in optical disk data reading. Using relatively simple data processing algorithms we were able to detect possible errors and position of the errors on the glass scale. Research showed that measurement method could be used for quality parameters evaluation, but requires usage of the laser pick up heads with known parameters.

关键词： glass scale optical focusing encoder glass scale defects quality control angular encoder

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Characterization of a self-calibrating, high-precision, stacked-stage, vertical dual-axis goniometer

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METROLOGIA 2016年第3期53卷 933-933页

作者： Mendenhall, Marcus H. Henins, Albert Windover, Donald Cline, James P. NIST 100 Bur Dr Gaithersburg MD 20899 USA

We present details on the alignment and calibration of a goniometer assembly consisting two stacked, optically encoded, vertical axis rotation stages. A technique for its calibration is presented that utilizes a stable, uncalibrated, third stage to position a mirror in conjunction with a nulling autocollimator. Such a system provides a self-calibrating set of angular stages with absolute accuracy of +/- 0.1 s of plane angle (k = 2 expanded uncertainty) around the full circle, suitable for laboratory application. This calibration technique permits in situ, absolute angular calibration of an operational goniometer assembly that is requisite for fully traceable angle measurement, as the installation of the encoder is known to change its performance from the angular calibration data provided by the manufacturer.

关键词： angle metrology goniometer long-range error angular encoder xrd diffraction

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Analysis and Self-Calibration Method for Asynchrony between Sensors in Rotation INS

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SENSORS 2018年第9期18卷 2921-2921页

作者： Sui, Jie Wang, Lei Huang, Tao Zhou, Qi Beihang Univ Sch Instrumentat Sci & Optoelect Engn Beijing 100191 Peoples R China Natl Key Lab Sci & Technol Aircraft Control Xian 710065 Shaanxi Peoples R China

The gyroscope, accelerometer and angular encoder are the most important components in a dual-axis rotation inertial navigation system (RINS). However, there are asynchronies among the sensors, which will thus lead to navigation errors. The impact of asynchrony between the gyroscope and angular encoder on the azimuth error and the impact of asynchrony between the gyroscope and accelerometer on the velocity error are analyzed in this paper. A self-calibration method based on navigation errors is proposed based on the analysis above. Experiments show that azimuth and velocity accuracy can be improved by compensating the asynchronies.

关键词： accelerometer angular encoder asynchrony fiber optic gyroscope (FOG) rotation inertial navigation system (RINS) self-calibration

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