Fanuc Corporation

Keisuke Imai

Mitsuyuki Taniguchi

Shunichi Odaka

Hirosato Yoshida

Nobuyuki Ootake

Youhei Kondou

Akira Nishioka

Hiroya Terashima

Ichirou Nagatomo

Shinichi Horikoshi

Takashi Harada

Masato Aochi

Tokuhisa Matsukane

Ichirou Fanuc Manshonharimomi Nagatomo

A rotation angle detector comprises a rotating body including a plurality of track parts, and an abnormality detecting unit for detecting an abnormality based on signals generated in detection units. The detection units generate a first signal based on a first track part and a second signal based on a second track part. The abnormality detecting unit includes a judgement unit for judging an occurrence of an abnormality when the difference between the fluctuation range of the first signal and the fluctuation range of the second signal is larger than a predetermined fluctuation range judgement value.

Rotation angle detector which can detect entry of foreign substances

An encoder according to an embodiment of this disclosure includes a voltage generation circuit connected to a power supply through a diode and having a variable resistor, the voltage generation circuit outputting a voltage corresponding to a current flowing through the diode and a resistance value of the variable resistor, as a threshold value; a comparator for performing a comparison between an analog signal inputted from a detector for detecting rotation of a motor and the threshold value inputted from the voltage generation circuit, and outputting a comparison result as a comparator output; a resistance value variation circuit for varying the resistance value of the variable resistor; and a threshold value determination circuit for determining the threshold value based on a relationship between the resistance value and the comparator output.

Encoder having function of adjusting threshold value of comparator and method for controlling encoder

An encoder according to an embodiment of this disclosure includes a voltage generation circuit connected to a power supply through a diode and having a variable resistor, the voltage generation circuit outputting a voltage corresponding to a current flowing through the diode and a resistance value of the variable resistor, as a threshold value; a comparator for comparing an analog signal inputted from a detector for detecting rotation of a motor with the threshold value inputted from the voltage generation circuit, and outputting a comparison result as a comparator output; an A/D converter for converting the analog signal into a digital signal; a threshold value determination circuit for calculating a new threshold value using the digital signal; and a resistance value change circuit for changing a resistance value of the variable resistor, such that the calculated new threshold value is inputted from the voltage generation circuit to the comparator.

A motor is provided that is capable of eliminating the need to prepare (develop, manufacture, or possess) motor bodies and rotary encoders of multiple different specifications by facilitating connections to motor bodies or rotary encoders having different contact positions. In a motorincluding a motor body and a rotary encoder, the motor body includes a motor body side connector with a motor body side contact and the rotary encoder includes a rotary encoder side connector with a rotary encoder side contact. The motor body side contactand the rotary encoder side contact are electrically connected. One or both of the motor body side contact and the rotary encoder side contact have a shape extending in a radial direction.

Motor

An encoder system includes an encoder for outputting positional data and magnetic pole data of an output axis of a motor; and a controller for communicating with the encoder. The encoder includes a positional data generation circuit; a magnetic pole data generation circuit; a first data abnormality detection circuit for detecting an abnormality based on the positional data and the magnetic pole data, and outputting a first alarm signal; and a parallel-to-serial conversion circuit for outputting the positional data, the magnetic pole data, and the first alarm signal to the controller. The controller includes a second data abnormality detection circuit for detecting an abnormality based on the positional data and the magnetic pole data, and outputting a second alarm signal; and a communication abnormality detector for detecting an abnormality in a communication path based on the first and second alarm signals.

Encoder system having function of detecting abnormality, and method for detecting abnormality of the same

A rotary encoder of the present invention has a hermetically sealed structure having at least one desiccant and an electric circuit by which the moisture absorbing amount of the desiccant can be obtained. The desiccant is arranged in a sealed space defined by a flange and a cover member. The electric circuit, a rotary slit plate, a light emitting element and a light receiving element are arranged in the sealed space.

Rotary encoder having function to obtain moisture absorbing amount of desiccant

An optical encoder of the present invention includes a light-receiving element unit, moving slitand fixed slit. The light-receiving element unitincludes a patternB for detecting infiltration of liquid.

Encoder that detects infiltration of liquid by light

A rotation angle detection apparatus includes a rotator having a track unit to detect the rotation angle of a rotation axis; a detection unit disposed in correspondence with the track unit; a rotation angle calculation unit for calculating the rotation angle of the rotation axis based on signals generated by the detection unit; a rotation speed calculation unit for calculating the rotation speed of the rotation axis; and an abnormality detection unit for detecting an abnormality. The abnormality detection unit includes a frequency analyzing unit for calculating the frequency characteristic of the signals; a storage unit for storing the number of the signals per revolution of the rotator; a signal frequency calculation unit for calculating a signal frequency; and a determination unit for detecting the abnormality in the detection apparatus, when the frequency characteristic includes a component of a higher order than the signal frequency.

Rotation angle detection apparatus having function of detecting entry of foreign substance based on frequency characteristic of signals

An encoder able to maintain liquid-tightness over a long period of time. The encoder is provided with a housing unit holding component parts of the encoder. The housing unit is formed by a housing and a cover closing an opening part of the housing. At a boundary part of the housing and the cover, an O-ring is placed. The housing is formed with a guide groove at the outside in the radial direction from the O-ring and a discharge guide groove communicated with the guide groove and opening toward the outside in the radial direction. The cover is formed with a ring-shaped guide projection projecting out toward the guide groove at a position corresponding to the guide groove.

Encoder having liquid-tight structure

A magnetic type angle sensor includes a rotary body having a first sensed part provided on a circumferential surface thereof with projecting parts and recessed parts at equal intervals in a circumferential direction thereof and a second sensed part provided on a circumferential surface thereof with a projecting parts at just one location, and a magnetic sensing device for sensing a change in a magnetic field along with rotation of the rotary body. The rotary body is formed with a plurality of projecting parts and recessed parts in a gear shape by gear cutting on the circumferential surface, then is cut with a groove at the center thereof in the axial direction thereof and has all projecting parts in a half section in the axial direction thereof cut off except for one.

Magnetic type angle sensor

An optical encoder, including a light emitting section; a light receiving section; and a resinous code plate disposed movably relative to the light emitting section and the light receiving section. The resinous code plate includes, on the plate face thereof, a plurality of tracks respectively provided with molded code-pattern surfaces different from each other, and a local structured-surface area formed between the tracks arranged side-by-side relative to each other, the local structured-surface area possessing a surface configuration different from the molded code-pattern surfaces of the tracks. The molded code-pattern surface of each of the tracks includes a flat surface area and an irregular surface area, adjacent to each other as seen in the extending direction of the track. The local structured-surface area is formed between the flat surface area of the molded code-pattern surface of one track and the irregular surface area of the molded code-pattern surface of another track arranged side-by-side relative to the one track. The irregular surface area of the molded code-pattern surface includes a first linear structure extending in a predetermined direction, and the local structured-surface area includes a second linear structure extending in a direction intersecting the first linear structure of the irregular surface area.

Optical encoder with resinous code plate

The invention aims to suppress or prevent the vibration that can occur due to the intervention of a low-rigidity part between detector and rotating body. An angular acceleration sensor for detecting the rotational angular acceleration of a rotating body is provided, and an angle/angular speed command value is compensated in accordance with the value of the angular acceleration.

Rotary shaft control apparatus

The invention aims to reduce an error occurring due to the mounting condition of an acceleration sensor. In the case of a two-axis sensor, an angle &#x3b8; is calculated from outputs (x', y&#x2032;) that the acceleration sensor produces when known accelerations (x, y) are applied, and the angle &#x3b8; is stored in a storage device contained in a casing in which the acceleration sensor is housed. In the case of a one-axis sensor, the ratio of the magnitudes of accelerations is stored. The acceleration detected by the acceleration sensor is compensated by using the value stored in the storage device.

Machine tool control apparatus

In a control apparatus, a 'characteristic value calculation' block calculates a characteristic value (such as amplitude value, offset value, or waveform distortion for each phase of two-phase sinusoidal signals optically input from an encoder, or phase difference between the two phase signals) for each of the two-phase sinusoidal signals, and an 'alarm detection' block checks the presence or absence of an excursion outside a predetermined allowable range and, if such an excursion is detected, produces an alarm indication or the like. Each time the &#x201c;present characteristic value&#x201d; is input, a &#x201c;characteristic value comparison&#x201d; block compares it with &#x201c;previous characteristic values&#x201d;, and analyzes the result of the comparison. That is, the difference between the present value and each previous data is calculated, and the largest amount of variation (with plus or minus sign) is obtained; if this amount is larger than a predetermined value, a signal indicating an &#x201c;imminent failure&#x201d; is output. In an alternative method, the present value is compared with a characteristic value calculated from an encoder reference signal. Further, the characteristic value monitoring and comparison may be performed within the encoder. In this way, data useful for the prediction of encoder failure, etc. is provided.

Encoder and control apparatus for motor

An optical encoder whose environmental resistance is improved by increasing the variety of options of materials for a resin-made code plate thereof. Used as material for at least a code pattern of the code plate of the optical encoder is one which meets the condition that the material has spectral transmittance of 70% or more with respect to detection light and that of 50% or less with respect to partial light (for example blue light) of visible wavelengths in translucent sections. If infrared light having wavelengths between 800 nm and 1000 nm is used as detection light, it is preferable to apply polyetherimide, polyethersulfone or polyphenylsulfone as a colored resin material. These materials are excellent in heat resistance, oil resistance, etc., compared to transparent and colorless materials (PMMA, PC, glass, etc.) which have been conventionally used, and hardly cause melting, deformation, white turbidity, etc., in a harsh environment.

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Yamanashi, Japan

Keisuke Imai