Fanuc Corporation

Hirofumi Kikuchi

Mitsuyuki Taniguchi

Hiromichi Horiuchi

Keiji Sakamoto

Katsuo Kobari

Shigeyuki Ushiyama

Taisei Fujimoto

Yoshitaka Takekoshi

Tokuhisa Matsukane

Takurou Hayashi

Hiroya Terashima

Tadayoshi Matsuo

Shouhei Nisino

An absolute encoder that receives a current from an electronic power supply includes: a plurality of regulators connected in parallel with one another that receive a drive current from an electronic power supply in which a magnitude of a constant voltage output to the absolute encoder and a magnitude of a drive current needed for outputting the constant voltage are different; a voltage detection unit configured to detect an output voltage of at least one regulator of the plurality of regulators; and an abnormality detection unit for detecting an abnormality of a current from an electronic power supply consumed when the absolute encoder is driven based on the output voltage detected by the voltage detection unit.

Absolute encoder including abnormality detection unit for detecting abnormality of consumption current

An encoder signal processor comprises an analog signal adjustment circuit for adjusting, based on an adjusting signal, at least one of an offset and an amplitude of a sinusoidal analog signal with two phases having a 90-degree difference outputted in accordance with a travel of a target to be measured, a position detection circuit for calculating position data of a target to be measured based on a digital signal obtained through analog/digital conversion of an analog signal adjusted, a velocity change amount detection circuit for detecting a change amount of velocity per predetermined detection cycle from a velocity calculated based on position data outputted while a target to be measured is traveling at a constant velocity, and an adjusting signal generation circuit for generating an adjusting signal that minimizes the change amount of velocity detected and transmitting the adjusting signal to the analog signal adjustment circuit.

Encoder signal processor having automatic adjustment function

A detector comprising a circuit board, a board-side connector which is mounted on the circuit board, and a flexible cable which has a terminal part inserted in the board-side connector, wherein a reinforcement member of the flexible cable is attached to an end part of the flexible cable which includes the terminal part, and the reinforcement member includes a foldable part which allows local bending of the end part of the flexible cable.

Method of producing a detector

When a communication abnormality occurs between an encoder and communication circuit apparatus in a work apparatus feeding back data output from encoders for control by a control apparatus, an encoder communication circuit is used in place of the encoder to identify the location of occurrence of the abnormality. The encoder communication circuit outputs encoder data comprised position or speed data and alarm data to said control apparatus when connected to the control apparatus through a communication cable.

Encoder communication circuit

An encoder having a function for detecting noise which may affect an internal signal of the encoder, without using a noise detecting circuit within the encoder, whereby the cost and size thereof may be reduced. The encoder has a detecting part adapted to detect the movement of an electric motor or a driven object; a signal processing circuit adapted to process a detection signal from the detecting part and obtain positional data of the motor or the object; and a transmitting part adapted to transmit the positional data from the signal processing circuit at regular time intervals and a fluctuation component calculated on the basis of the positional data, to external equipment. The signal processing circuit has a fluctuation component detecting circuit adapted to detect a fluctuation comment included in the calculated positional data, and the detected fluctuation component is transmitted to the external controller as an amount of noise.

Encoder having function for detecting amount of noise

In an encoder which is equipped with two detectors arranged on both sides of a rotating shaft in order to eliminate an eccentricity error, the mounting of the detectors is facilitated by making provisions so as to not cause a problem in the calculating of an average even if the detectors happen to be so mounted that the difference between the angular values calculated from the outputs of the respective detectors becomes equal to 180&#xb0;. In an initialization process after power on, the difference &#x394;&#x3b8; between the angular values &#x3b8;and &#x3b8;calculated from the signals output from the respective detectors is stored as an initial value. Position data &#x3b8; is output by taking an average between &#x3b8;and &#x3b8;, where &#x3b8;is a value obtained by correcting &#x3b8;by the initial difference &#x394;&#x3b8;.

Signal processing circuit for encoder

An encoder that can detect the presence of noise occurring within the encoder. The encoder is constructed by incorporating within the same apparatus: a movement detecting unit for detecting the movement of a moving body; a signal processing circuit for processing a movement detection signal supplied from the movement detecting unit, and thereby producing an encoder signal representing the position and/or the amount of displacement of the moving body; and a noise detecting unit for detecting noise superimposed on the movement detection signal. According to this encoder, a noise voltage generated within the encoder via a stray capacitance is detected within the encoder and is output as noise data, so that the noise level can be detected without requiring the use of an external measuring device. Further, by outputting encoder data and noise data occurring at the same instant in time, the reliability of the encoder data can be judged based on the condition of the noise level.

Encoder for detecting position or displacement of moving body

An assembly of electric motor with encoder, including an electric motor having a motor housing, and an encoder for detecting the rotation angle of the output shaft of the electric motor. The encoder includes a frame member attached to the motor housing in a conductive manner, a circuit board supported on the frame member and a detection circuit provided in the circuit board. The assembly of electric motor with encoder further includes an output signal cable connected to the circuit board of the encoder and including a signal wire and a shield member, and a grounding mechanism electrically connecting the shield member of the output signal cable to the motor housing for grounding purposes. The grounding mechanism includes a conductor patterned on the circuit board, a first connecting structure mutually connecting the conductor to the shield member, and a second connecting structure mutually connecting the conductor to the frame member. The second connecting structure includes a through-hole plating provided in the circuit board to be connected to the conductor, and a fastening element inserted into a through hole having the through-hole plating and securing the circuit board onto the frame member. When the fastening member is fastened, the through-hole plating comes into conductive contact with the frame member.

Grounding mechanism for electric motor with encoder

An industrial machine in which vibration exerted on a position detector provided for an axis of the machine is detected and countermeasures against the vibration can be swiftly taken. A ball screw is driven by a servo motor MZ supplied with power from a servo amplifier via a power line so that a cutting unit is advanced and retracted. A spindle motor MS above the cutting unit rotates a cutting tool via a spindle shaft and a workpiece W on an XY table is machined. An acceleration detection element is built in a position detector attached to a motor shaft of the servo motor MZ. An angle detection signal for servo control and a vibration level signal outputted by the acceleration detection element are converted into serial signals and are transmitted to a controller (axis control circuit of Z-axis) via the common signal line. The controller takes measures of changing the machining condition (for example, change of spindle rotational speed) and stopping the machine in accordance with a rank of the vibration. A duration or total time period of the abnormal vibration may be monitored.

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Yamanashi, Japan

Hirofumi Kikuchi