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Author

Richard D. Koski

Bio: Richard D. Koski is an academic researcher. The author has contributed to research in topics: Transducer & Electromagnetic coil. The author has an hindex of 4, co-authored 4 publications receiving 168 citations.

Papers
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Patent
24 Sep 1987
TL;DR: In this paper, a magnetostrictive wire is used to measure liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.
Abstract: A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted the wire near the top to travel along the wire to a magnet which is contained within a liquid level float which slides up and down along the tube. The torsional disturbances imparted to the wire by means of a piezoelectric crystal to which the wire is easily clamped. Accuracy is enhanced by measuring liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.

55 citations

Patent
03 Apr 1989
TL;DR: In this article, a magnetostrictive wire is used to measure liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.
Abstract: A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted the wire near the top to travel along the wire to a magnet which is contained within a liquid level float which slides up and down along the tube. The torsional disturbances imparted to the wire by means of a piezoelectric crystal to which the wire is easily clamped. Accuracy is enhanced by measuring liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.

45 citations

Patent
08 Dec 1989
TL;DR: A magnetostrictive linear displacement detector with increased position resolution was proposed in this paper, where the displacement is determined from the interval of time between the detection of the torsional motion traveling directly from the magnet and the detection reflected from the reflection termination.
Abstract: A magnetostrictive linear displacement detector with increased position resolution includes a magnetostrictive wire anchored at opposite head and foot ends with a reflection termination at the foot end and a damping termination at the head end. A return wire is connected to the foot end of the magnetostrictive wire. The magnetostrictive wire is electrically excited at its head end. A variable position to be detected is represented by a magnet disposed for displacement along the magnetostrictive wire. A torsional motion sensor at the head end generates an electrical indication of the torsional motion within the magnetostrictive wire induced by passage of the electrical excitation by the position of the magnet. The displacement is determined from the interval of time between the detection of the torsional motion traveling directly from the magnet and the detection of the torsional motion reflected from the reflection termination. The reflection termination preferably consists of a brass cylindrical torus having a hole through which said magnetostrictive wire is passed and attached via a set screw. In an alternative embodiment the magnetostrictive wire is torsionally excited and the responses are detected electrically.

44 citations

Patent
15 Oct 1993
TL;DR: In this article, a magnetostrictive linear displacement detector with an axial coil torsional strain transducer is presented, where the transducers are two serially connected coils wound in opposite directions.
Abstract: The present application discloses a magnetostrictive linear displacement detector with an axial coil torsional strain transducer. The displacement detector includes a magnetostrictive wire, a return wire and a magnet disposed for displacement along the magnetostrictive wire. A torsional strain sensor at the head end generates an electrical indication of the torsional strain within the magnetostrictive wire induced by passage of an electrical excitation by the position of the magnet. The torsional strain sensor includes two serially connected coils wound in opposite directions. The total length is short compared with the rate of electrical propagation within the magnetostrictive wire and long compared with the rate of torsional strain propagation within the magnetostrictive wire. The induced current within the two coils from electrical excitation of the magnetostrictive wire substantially cancel out because generally the whole sensor is excited simultaneously. The torsional magnetic disturbance accompanying the propagating strain, which is of a much narrower extent, generally induces current in only one of the two sections at a time. This transducer is advantageous because the response in not critically dependant on location.

24 citations


Cited by
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Patent
02 Jun 2000
TL;DR: In this article, a position feedback system is used to determine the position of movable elements on a path and control the movable element on the path and the programmable controller using positional information from the sensors.
Abstract: The present invention is directed to a machine with a position feedback system and a method for use thereof. The machine includes at least one movable element mounted for movement on a path and at least one programmable controller. The machine further includes at least two absolute or magnetostrictive sensors or the machine includes an absolute sensor and a non-absolute sensor. The programmable controller uses positional information from the sensors to determine the position of the movable elements on the path and control the movable elements. The method includes determining a known position for the movable elements, linking at least two magnetostrictive sensors into one virtual sensor, and/or performing commutation alignment for the movable elements. Determining the position and commutation alignment can occur when the movable elements are stationary or moving.

379 citations

Patent
29 Dec 2000
TL;DR: In this paper, an integrated vehicle ride height system control system was proposed for use with a motor vehicle having at least one fluid-pressurized height adjusting member having first and second separable components.
Abstract: The present invention is intended for use with a motor vehicle having at least one fluid-pressurized height adjusting member having first and second separable components. Apparatus constructed in accordance with the invention includes an integrated vehicle ride height system control system. The control system includes an electronic output drive signal circuit and input signal interpretation circuit to electronically interface with at least one position sensor. The position sensor provides output signals related to extent of separation of said first and second separable components of the fluid pressurized height adjusting member.

85 citations

PatentDOI
TL;DR: In this paper, a magnetostrictive transducer measuring system for precisely measuring the liquid level of fuel in an underground tank is described, where a current pulse is applied to the transducers and sonic pulses are simultaneously produced through the interaction of the magnetic field of transducers with the magnetic fields of the magnets.
Abstract: A magnetostrictive transducer measuring system for precisely measuring the liquid level of fuel in an underground tank. The system provides for the measurement of the position of one or more transducer magnets in a tube that are positioned along a length of the transducer wire therein, with one of the magnets fixed in the tube to provide a reference position. A current pulse is applied to the transducer wire and sonic pulses are simultaneously produced through the interaction of the magnetic field of the transducer wire and the fields of the magnets. The sonic pulses are detected by a sensor and the time interval between the detected sonic pulses is determined to determine the distance between the magnets.

49 citations

Patent
20 Jul 1992
TL;DR: In this article, a position detection probe has a magnetostrictive wire stretched between a head and a reflective foot end termination, and a magnet displaceable along the probe and using the sonic pulse propagation time from the magnet to the foot as a position detector, compensation for thermal expansion and thermal change of propagation velocity is made based on the property of the total propagation time along the wire length being a unique function of temperature.
Abstract: In a position detection probe having a magnetostrictive wire stretched between a head and a reflective foot end termination, and a magnet displaceable along the probe and using the sonic pulse propagation time from the magnet to the foot as a position detection parameter, compensation for thermal expansion and thermal change of propagation velocity is made based on the property of the total propagation time along the wire length being a unique function of temperature and calibrating the probe at different temperatures to yield either equations or look up tables of true positions as functions of the total propagation time and the position detection parameter. By mapping wire characteristics at a plurality of magnet positions and temperatures to construct look up tables, wire nonlinearities as well as thermal effects can be compensated for.

46 citations

Patent
07 Mar 1996
TL;DR: A magnetostrictive linear displacement transducer as mentioned in this paper includes an elongated member of a material with a large magnetostriction coefficient, and a coil and a pulse driver for magnetizing the member to cause a magnetic effect for short discrete periods of time.
Abstract: A magnetostrictive linear displacement transducer includes an elongated member of a material with a large magnetostriction coefficient. There is a coil and a pulse driver for magnetizing the member to cause a detectable magnetostrictive effect for short discrete periods of time. A magnet is movable along the path adjacent the member and is capable of magnetizing a localized portion of the member adjacent the magnet efficiently to cause an alteration in the magnetostrictive effect in the localized portion in concert with the pulse driver and the coil. There is a piezoelectric device at one end for detecting axial strain pulses propagated along the member caused by the magnetostrictive effect. There is a comparator for measuring time lags between initiation of each separate discrete period of time and detection of a corresponding strain pulses by the piezoelectric device and thereby a position of the magnet along the path.

46 citations