Abstract: A data recorder in which a recording is moved by stepping motor whose rotor rotation angle is detected, the stepping motor having a current switching circuit which controls the application of excitation current to the drive coils of the motor in accordance with the detected rotation angle. A control circuit counts the detected result of the rotor rotation angle, detects the position of the head and generates start and stop control signals of the head, thereby starting and stopping switch-over control of the current switching circuit being effected.

Abstract: An involute interpolation method for machining operations is used in a numerical control apparatus.A rotational direction (G03.1) of an involute curve, an incremental distance along the involute curve or an incremental angle, a center position (X.sub.0, Y.sub.0) of a base circle and a radius (R) of the base circle are obtained per the instruction. The involute curve is interpolated using a predetermined distance or predetermined angle.The above processing is executed with a numerical control apparatus and pulse distributions are continuously carried out. Therefore, the involute curve can be interpolated without need for a special program producing system.

Abstract: A position and speed detecting device is provided. This device includes a detection-signal generator comprising a rotor magnet assembly having a plurality of magnetic poles and a coil pattern for signal detection which moves relatively facing magnetized bodies of the rotor magnet assembly, a speed-signal detector for taking out a signal for frequency detection from said coil pattern for frequency-signal detection to produce a signal for speed detection; and a position-signal detector for producing a signal for position detection from said coil pattern for position-signal detection.

Abstract: A rotor movement warning device for use in a stepper motor has a stator provided with a plurality of windings and a rotor rotatably provided in associated with said stator. The rotor movement warning device includes a power source, a plurality of switching transistors provided in association with the plurality of windings, respectively, for controlling power supply from the power source to the windings, and a driving pulse producer for producing driving pulses to the plurality of switching transistors for effecting the rotation of the rotor. Further provided are detector for detecting, when the rotor stops, at least one switching transistor which is provided with the last driving pulse, and low frequency signal producer for producing low frequency signals which are applied to the switching transistor detected by the detector.

Abstract: A sampled data read/write head positioning system for a disk drive having a sector servo overcomes the low bandwidth constraints of feedback position samplers. The system includes controlled acceleration and controlled deceleration of the read/write heads while seeking a track. In order to avoid missing track addresses, the sectors on each disk surface are staggered (offset) along each track from the corresponding sectors on the other disk surfaces, and each read/write head is used to find a particular track by sequentially switching the read/write heads while seeking.

Abstract: An electronic absolute coordinate encoder for positional control devices which includes an encoding section, a detector section, a counter section and a backup power source. The encoder can detect the current position of the positioning system continuously even in case of power interruption and thus the positioning system may not be returned to the original position for the purpose of performing the position control, when the power interruption ends.

Abstract: The invention is a servomotor control apparatus for controlling the positioning of a movable element of an industrial robot or NC machine tool. An NC unit or a robot controller detects displacement from a movable element that is to be positioned, such as a table, forms a position command regarding a servomechanism, and has a correction circuit (A) which receives quadrant data (BLF) regarding a backlash correction command. When there is a quadrant reversal for each axis of the movable element, frictional torque corresponding to the axis is stored and a torque correction command (FR) corresponding thereto is outputted. A torque command of a fully-closed loop servo system for performing control based on a fed back position detection signal is corrected by the torque correction command. The servomotor control apparatus can be applied to semi-closed loop servo system in which a backlash correction is possible, and not just to a fully-closed loop servo system.

Abstract: A plurality of speed-sliding compensation amount functions are stored in a sliding compensation amount data memory and one of these functions is selected in response to input of a selection signal. In the selected function, sliding compensation amount data corresponding to the speed of the object of positioning is read out. At least one of current position data and positioning target position data of the object is corrected by the read out sliding compensation amount data. A brake signal is generated on the basis of comparison of the current position data and target position data which have been subjected to this correction and a positioning control of the object is performed by this brake signal. On the other hand, a sliding amount detection circuit is provided for detecting sliding amount of the object from generation of the brake signal until actual stop of the object.

Abstract: Disclosed herein is a numerical control apparatus for controlling drive spindle heads in a rectangular coordinate system of machining apparatuses such as a lathe, a miller, a laser beam machining apparatus, an electric discharge machining apparatus, a robot and the like, to thereby perform positioning control.

Abstract: A control device for a servo motor comprises feedforward means for correcting a speed reference obtained by a position control device by a correction amount obtained on the basis of an objective position or an objective speed of the servo motor so that a response delay of the position control device for obtaining a reference speed necessary to control the rotation angle position of the servo motor to an objective rotation angle position is compensated for while restricting vibration.

Abstract: Operating device for the cover of a sliding and lifting sunroof of a motor vehicle having a desired value transmitter and an actual value transmitter for controlling the sliding sunroof function and the lifting roof function via an actuator that is part of a control circuit. By the control circuit, the desired value signal supplied by the desired value transmitter and corresponding to the respective desired position of the cover selected is compared with an actual value signal of the actual value transmitter corresponding to the respective actual position of the cover to cause the cover position to be adjusted until the actual cover position matches that desired. The operating element of the desired value transmitter is mounted, to slide for producing for a sliding of the cover, and to swing for producing a cover tilting-out movement.

Abstract: A drive system for a double-sided floppy disc includes a head for each side of the disc, a stepper motor responsive to stepper motor control signals for moving the heads to predetermined tracks on the floppy disc, and a control circuit for generating the stepper motor control signals in response to commands from the computer. The tracks on the floppy disc are disposed with the first "n" tracks on one side of the floppy disc and the "N+1"st track and remaining tracks on the other side. The "n"th and "n+1"st tracks are disposed adjacent each other along a boundary of the disc but on opposite sides of the disc. The control circuit generates a first predetermined sequence of stepper motor control signals to move the first head in the direction from the preceding tracks toward the "n"th track and a second predetermined sequence of stepper motor control signals to move the second head in the direction from the "n+1"st track to succeeding tracks.

Abstract: A control topology for a servo motor carriage drive includes a strain gauge coupling the carriage to a motor-driven belt to provide a signal representative of the flexure of the belt. A velocity signal is taken from a linear encoder on the carriage. These signals are used in inner and outer feedback loops for controlling the velocity of the carriage as it travels along a predetermined path.

Abstract: An apparatus for detecting and analyzing a fault condition occurring in an engine electrical generator set (21) while providing means for inhibiting the engine electrical generator set (21) upon the occurrence of the fault. The apparatus utilizes a run relay (22) connected in series with single contact fault senders (26) to a reference potential. The single contact fault senders (26) monitor various parameters of the engine electrical generator set (21). When a parameter is exceeded, the single contact fault sender (26) opens, de-energizing run relay (22) thereby inhibiting engine electrical generator set (21). Optical isolators (27) monitor the single contact fault senders (26) and provide information on their status to logic determining means (24) to alert an operator of an exceeded parameter. Also provided is a bypass switch (31) to bypass single contact fault senders (26).

Abstract: A sector is provided on a rotary shaft of a stepping motor. Two end edges of this sector define two reference positions. When a sensor detects one of the end edges, a reset signal generator generates a reset signal to reset a counter which counts driving pulses for the stepping motor or fractions thereof. The reset signal generator also generates a distinguishing signal representing which end edge of the sector is detected. The rotary position of the stepping motor is determined based on the content of the counter and the distinguishing signal.

Abstract: A separate adaptive noise canceller receiving a reference input of a rotor speed synchronization pulse is connected in the X and Y axis positional control loops of a magnetic bearing utilized to position a rotor suspended thereby. The output of the noise canceller is self-adjusting by the inclusion of an adaptive filter implementing a least mean square algorithm to force the gain of the control loop to zero at not only the fundamental of the rotational speed, but all harmonic frequencies thereof, thereby reducing the vibration and control system power dissipation of the magnetic bearing at the rotational fundamental as well as at the rotational harmonics.

Abstract: A PWM circuit for generating a PWM wave which is pulse-width modulated in response to binary information and is used for a signal such as a motor driving signal in an R-DAT (rotary head type digital audio tape recorder) comprises a circuit for dividing binary information such as a motor speed error signal provided for generating a PWM wave into plural bit groups and generates PWM waves corresponding to numerical values of these plural bit groups, and a circuit for weighting the generated PWM waves in an analog manner at a ratio corresponding to orders of the respective bit groups and adding the weighted PWM waves. Since binary information is divided into plural bit groups, the bit number of each bit group is small so that the period of PWM wave can be shortened without reducing the quantization bit number of the binary information or shortening reference clock period whereby accuracy of an error signal can be improved when the invention is applied to, e.g., a motor drive device.

Abstract: The invention relates to a method and a controlling apparatus for controlling the magnitude and direction of a current (I) through a winding (L). The method and controlling apparatus are based on a drive circuit (TR.sub.1, D.sub.1, TR.sub.2, D.sub.2, TR.sub.3, D.sub.3, TR.sub.4, D.sub.4) which is controllable such as to enter into three different types of operational state. In a first type of operational state the current is normally increasing in magnitude. In a second type of operational state the current is normally decreasing in magnitude comparatively slowly. In a third type of operational state the current magnitude is normally decreased comparatively rapidly.

Abstract: A pulse motor control apparatus for a polyphase excitation type pulse motor variably and independently controls excitation currents supplied to excitation coils. Ratios of any excitation current to other excitation currents supplied to the excitation coils are changed stepwise to rotate a composite magnetic field vector forward by those excitation coils each multiple of a real number of a predetermined unit angle at one time for controlling the rotational angle of a rotor of the pulse vector. The pulse motor control apparatus assures fine control for the rotational angle of the rotor compared with prior cases where currents supplied to a plurality of excitation coils are switched on and off for rotational control. Application of the present control apparatus to printers, etc., precludes replacement of gears, etc., due to types of print heads mounted thereon. Additional advantages such as inprovement of a torque ripple upon driving the pulse motor assure extensive application to various fields.

Abstract: Drive apparatus, particularly for a twin polygon thermal scanner, utilizes a stepper motor driven by pulses of variable width timed, relative to the rotational position of the motor, so that the pulses are substantially centred on the maximum torque position of the motor. This minimizes power consumption. The control circuitry for the motor performs a start sequence, which is aborted and reinitiated in the event that the motor fails properly to start and in which the frequency of the pulses applied to the stopper motor is increased as the motor accelerates. Any excessive increase in the rate of increase of frequency of the pulses is detected and corrected. When the motor is running up to speed, the power applied to the motor is controlled by a phase detector which detects variations in phase between a referenced pulse train and a pulse train generated by the rotation of the motor.