Abstract: Under the conditions that the tool is movable in an X-axial direction for approaching a work W and in a Y-axial direction perpendicular to the X-axial direction, the tool is moved at a specified speed in the X-axial direction to make the tool approach a work W and at the same time the tool is reciprocally moved at a specified frequency and a specified amplitude to detect a load fluctuation component for the tool in the X-axial direction during movement of the tool, and contact between the tool and the work W is detected according to this load fluctuation component.

Abstract: According to the present invention, in a first acceleration after power is turned ON, currents flowing through U-phase and V-phase of a servo motor output terminal are detected, and misconnection of the motor output terminal is detected by monitoring a pattern of the current wave form.

Abstract: According to the present invention, in a first acceleration after power is turned ON, currents flowing through U-phase and V-phase of a servo motor output terminal are detected, and misconnection of the motor output terminal is detected by monitoring a pattern of the current wave form.

Abstract: A movable body is moved towards an object for contact, it is determined whether a representative load for driving load such as a current instruction value for a servo amplifier providing controls for movement of the movable body has exceeded a reference value or not, and when the current instruction value exceeds the reference value, positional data for the body at this point of time is written in a memory, difference between the current instruction value and the reference value at this point of time and on is accumulated, and when the accumulated difference value reaches a specified value, a position indicated by the positional data in the memory is regarded as a contact position.

Abstract: According to the present invention, in a first acceleration after power is turned ON, currents flowing through U-phase and V-phase of a servo motor output terminal are detected, and misconnection of the motor output terminal is detected by monitoring a pattern of the current wave form.

Abstract: An absolute position detection apparatus which comprises sine and cosine wave generators for generating one or more sets of sine and cosine waves within a cycle, analog-to-digital converters for converting the incoming sine and cosine waves generated by the sine and cosine wave generators into digital values. An arithmetic unit is used for calculating a compensation for errors including offset, amplitude and phase errors on the basis of the digital values from the analog-to-digital converters. In the apparatus, the arithmetic unit operates on a phase angle from phase angles found by the arithmetic performed prior to or during said error compensations and the digital values from the analog-to-digital converters, whereby a low-priced, highly reliable absolute position detection apparatus can be achieved without the addition of compensation circuits to the hardware.

Abstract: A position control system for feeding back position information detected by position detection means for detecting the position of a machine movable part, is disclosed. The system includes a second order system position control loop formed by providing an internal second control loop. By adequately setting the internal control loop gain, a high response and stable control loop and also smooth response waveform can be obtained, thus ensuring vibration-free operation of the machine.

Abstract: An inverter apparatus and an inverter controlling method for judging a P-N impedance fault, a ground fault or a transistor fault by respective predetermined judging circuits according to either a voltage developed across a smoothing capacitor or the rate of change in the voltage while the smoothing capacitor is being charged. The charging of the capacitor is carried out via a resistor circuit or before the resistor circuit is short-circuited by a relay.

Abstract: The position of a machine tool or the like is accurately obtained by an absolute value encoder. Light emission elements emit light which passes through scales containing optical patterns and is detected by light receiving elements. First, a signal detected by the light receiving elements while the light emission elements are extinguished is stored in memory. Then, the light emission elements are lighted and the signal detected by the light receiving elements is corrected by the previously stored signal.

Abstract: A servo control apparatus comprises an abnormality detection circuit which calculates a difference between the quantity of rotation of a servo motor from a reference point calculated on the basis of an accumulated value of the position feedback and the quantity of rotation of the servo motor from the reference point counted by a rotational detector, and puts out an absolute position abnormality signal when the calculated difference value exceeds a predetermined value.