Sony Precision Technology Inc.

Dmg Mori Seiki Co., Ltd.

Sony Magnescale Inc.

Dmg Mori Company Limited

Shigeru Ishimoto

Masaaki Kusumi

Yusuke Takei

Toyohiko Matsuda

Masato Tanaka

Mitsugu Yoshihiro

Katsumi Kitamura

Yasuo Nekado

Mitsuru Ohno

Michio Okano

Kayoko Taniguchi

Yasuhiko Matuyama

Daisuke Uchiyama

Hideo Maejima

Chihiro Murayama

Koichi Hihara

Data is utilized more efficiently and effectively. A position detection device includes a plurality of scales that each record absolute data embedded with a scale ID for identifying a scale, a detector that detects the absolute data from each of the plurality of scales, and an extractor that extracts, from the detected absolute data, the scale ID and position data representing the position of the scale.

Position detection device and conveyance device

Provided is a highly reliable abnormal state determination system that can prevent erroneous determination even in a case where a determination condition for determining an abnormal state in measurement using a sensor cannot be changed. Provided is an abnormal state determination systemincluding: an abnormal state determination unitconfigured to determine an abnormal state by using a detection signal based on a signal output from a sensor; and a specific processing unitconfigured to, when a predetermined condition is satisfied, perform control processing for adjusting strength of the detection signal before the detection signal is input to the abnormal state determination unit

Abnormal state determination system

A magnetism detecting element detects a leakage magnetism from a scale, on which a magnetic signal with a constant period is recorded, and a relative position between the scale and the magnetism detecting element is detected. The magnetism detecting elements are arranged, along a detection direction of the magnetic signal relative to the scale, in a pattern with a pitch of &#xbd;n (n is a prime number of 3 or more) of a wavelength &#x3bb;' of a signal output by the element. Furthermore, as the pattern for cancelling m odd-order harmonics, the m-th power of 2 magnetism detecting elements are arranged within a range in which a pitch distance L of the magnetism detecting element farthest in the detection direction is expressed by L=(&#x3bb;&#x2032;/2)&#xd7;(&#x2153;+&#x2155;+ 1/7+ . . . 1/(2m+1)).

Position detecting device

A magnetism detecting element detects a leakage magnetism from a scale, on which a magnetic signal with a constant period is recorded, and a relative position between the scale and the magnetism detecting element is detected. The magnetism detecting elements are arranged, along a detection direction of the magnetic signal relative to the scale, in a pattern with a pitch of 1/2n (n is a prime number of 3 or more) of a wavelength &#x3bb;' of a signal output by the element. Furthermore, as the pattern for cancelling m odd-order harmonics, the m-th power of 2 magnetism detecting elements are arranged within a range in which a pitch distance L of the magnetism detecting element farthest in the detection direction is expressed by L=(&#x3bb;&#x2032;/2)&#xd7;(1/3+1/5+1/7+ . . . 1/(2m+1)).

A highly accurate position detection is performed by the use of a magneto-resistance effect element such as a TMR element. At least two magnetic detecting elements-and-are provided to detect leakage magnetism from a scalehaving a magnetic signal magnetically recorded thereon, and to output a recording signal of a position where the leakage magnetism is detected. The at least two magnetic detecting elements-and-are disposed side by side in a direction y perpendicular to a direction x of scanning the scaleand also disposed at positions approximately equidistant from a magnetic signal recording surface of the scale

A position detecting device that includes a recording medium provided with a first recording track in which a non-repetitive signal composed of binary information is recorded and a second recording track in which a signal for specifying a reading section within a section of information of 1 unit for the non-repetitive signal and information reading means that includes a first detection head and a second detection head and for reading each 1 unit information of the non-repetitive signal from the first recording track by using the first detection head in the reading section within a section of information of 1 unit for the non-repetitive signal specified based upon the signal recorded in the second recording track by the second detection head.

Angle data ranging from 0&deg; to 360&deg; obtained by performing polar conversion with respect to a periodic signal are input to a low pass filter having: a phase accumulator for outputting smoothed angle data; a phase comparator for obtaining a phase error between the angle data and the smoothed angle data; a first amplifier for amplifying the phase error; a second amplifier for further amplifying the phase error; an integrator for integrating the phase error PE amplified by the second amplifier to obtain a velocity error; and an adder for adding the phase error amplified by the first amplifier and the velocity error to determine a control voltage. The phase accumulator controls the frequency of the smoothed angle data so that the phase error is zero based on the control voltage to remove a high frequency component in the angle data.

Position detection apparatus and arithmetic processing unit

A position transducer capable of accurately detecting an n-bit code by a small number of ABS detectors when there is provided one ABS track. In an ABS head, the ABS detectors to are disposed for a distance &lgr; between the first ABS detector and (n&plus;m)th ABS detector to satisfy a requirement (n&minus;1)&lgr;&plus;2&dgr;<&lgr; and a distance &lgr; between two successive ones of the ABS detectors to satisfy a requirement 2&dgr;<&lgr; <&lgr;&minus;2&dgr;, so that at least one ABS detector is opposite to a stable area T in each of micro-areas at successive bits.

Position transducer

There is provided a position transducer ( ) capable of accurately detecting an n-bit code by n ABS detectors from one ABS track. When an INC value is under j or over k, signal output from each of the ABS detectors is binarized based on a threshold h and also based on a threshold l. First, an ABS value decider ( ) decides that a bit is &ldquo;H&rdquo; when it has been judged as being &ldquo;H&rdquo; on the basis of both the thresholds and a bit is &ldquo;L&rdquo; when it is has been judged as being &ldquo;L&rdquo; on the basis of both the thresholds. When the INC value is under j, a lower bit has the same code as that of the deiced bit. So, the ABS value decider ( ) decides that the lower bit is &ldquo;H&rdquo; or &ldquo;L&rdquo;. On the other hand, when the INC value is over k, an upper bit has the same code as the decided code. Thus, the ABS value decider ( ) decides that the upper bit is &ldquo;H&rdquo; or &ldquo;L&rdquo;. The ABS value decider ( ) decides a yet-to-decide bit to be &ldquo;L&rdquo; when a bit adjacent to the bit is &ldquo;H&rdquo;, and &ldquo;H&rdquo; when the adjacent bit is &ldquo;L&rdquo;.

A stable signal is output in which when there is no movement, unstable output change does not occur, and an output change exceeding a predetermined limit does not occur. The variation &Dgr;PH in the output angle signal PH to be output is subjected to hysteresis and through rate limitations with respect to the variation APF in the input angle signal input thereto. When the variation APF in the input signal is in a hysteresis range of &minus;Hys<&Dgr;PF<&plus;Hys, the variation in the output angle signal is output as 0. When the variation &Dgr;PF in the input signal is in a hysteresis range of &Dgr;PF<&minus;(Hys&plus;SR) or &Dgr;PF>(Hys&plus;SR), a through rate limitation is effected to thereby clip the variation in the output angle signal to SR. When the variation &Dgr;PF is in other regions, the output follows the input linearly with the output delayed by the hysteresis quantity.

Position detection apparatus

A position detector detects the position of a detector section relative to a record medium having recorded thereon a periodic position signal. The detector section has two detectors that produce first and second detection signals that are polar converted and processed, based on the number of divisions in a quadrant of the periodic position signal.

A displacement detecting apparatus includes a scale having a graduation of predetermined pitches, a sensor which is displaceable with respect to the scale and detects a period signal corresponding to the pitch. Interpolating sections interpolate the periodic signal from the sensor by different resolutions. One of the interpolating sections outputs a first interpolation signal of m (positive integer) phases shifted by a phase difference .theta.1, and the other interpolating sections outputs a second interpolation signal of n (positive integer) phases shifted by a phase difference .theta.2.

Position detecting apparatus

A displacement detecting apparatus outputs a displacement information signal obtained by interpolating a phase modulation. A direction block obtains a direction signal indicative whether the cycle of the phase modulation signal is longer than the cycle of the reference signal. A phase difference block obtains the number of the interpolation clock pulses which number corresponds to a phase difference between the phase modulation signal and the reference signal. An up/down counter counts to an interpolation number upon receiving the direction signal and a pulse train corresponding to the phase difference. The presetting block presets the number of pulses corresponding to the phase difference in the up/down counter. The displacement information block outputs a Glay code converted from continuous 2 bits of the count value of the up/down counter as displacement information.

Displacement detecting apparatus

In apparatus and method for measuring a displacement of an object to be measured, a magnitude of the displacement is derived on the basis of a difference in periods of a phase modulated signal and a reference signal, a ratio between the periods of a basic clock and of an interpolation clock which is varied according to the magnitude of the displacement, a clock signal whose period is a multiplication of a period of the basic clock by the ratio as a multiplier, a pulse train signal is created whose number of pulses are given by the magnitude of the displacement and supplied to an A/B phase converter.

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Kanagawa, Japan

Shigeru Ishimoto