Abstract: A driving system for a stepping motor wherein the stepping motor is rotated by a predetermined angle for each driving step. The system counts the time between two successive driving triggers, and changes at least one of the phase energization current and the phase energization time at the start of the driving of the stepping motor in response to the time count.

Abstract: A carriage moves on a track and carries, through a flexible linkage, a chassis to which is fixed a payload including an optical element. A linear actuator controls the linkage so as to correct imperfections in displacement of the payload. A piezo-electric accelerometer delivers a filtered signal to control the linear actuator so as to eliminate the effect on the payload of vibration of the carriage. There are two independent control loops, one for controlling the carriage and the other for controlling the chassis. The device is applicable to controlling the mobile part of an optical delay line or of a telescope in a stellar interferometer.

Abstract: A signal generator 16 is disclosed. The invention is adapted for use with industrial positioning systems and includes an integrating circuit 22 for integrating an input error signal to provide an output error signal and a limiting circuit 24, connected between the input and output of the integrating circuit 22 for limiting the output error signal. The output error signal is then used in a conventional manner to control a work piece or an implement. The integration of the low level input error signal rapidly increases the power delivered to the positioning system to overcome initial static friction. When the amplitude of the error signal indicates that the industrial apparatus is within a predetermined tolerance, the amplitude of output error signal decreases exponentially to diminish rapidly the power delivered to the positioning system. The apparatus will therefore be positioned within a given tolerance range.

Abstract: A stepper motor control circuit having a reduced number of discrete components is provided by using an on-chip analog to digital converter of a single chip microcomputer to control the waveforms of chopped winding currents. Four power MOSFET's, four diodes and two sense resistors can be added to the circuitry of a board populated by the single chip microcomputer to implement a full step motor controller. The addition of a holding current circuit frees the computer for servicing other tasks when the motor is idle.

Abstract: A position monitor is provided for use in conjunction with a stepper motor wherein two imputs are provided to the monitor from the stepper motor phase windings. A first signal is provided which indicates, by pulses, the rising and falling edges of in the magnitudes of both phase winding signals. A second signal is provided to indicate the direction of rotation of the stepper motor. The first and second signals are used as inputs to a plurality of counters which maintain a digital value representing the position of the stepper rotor. The digital value is converted to an analog value and amplified for use as a signal representing, by its magnitude, the precise position of the rotor of the stepper motor. The monitor therefore maintains a digital value and outputs a voltage signal which represent the position of a stepper motor rotor as it rotates through a plurality of clockwise and/or counter-clockwise revolutions.

Abstract: As disclosed herein, a new and improved method and apparatus provide for fine tuning the position of a servomotor used to drive a transducer mounted on an ultrasound probe to a desired position. This improvement is accomplished by processing the analog quadrature output signals of an incremental optical encoder, coupled to the servomotor. The improvement uses the positional information derived from the analog quadrature output signals. The analog quadrature output signals, defined as sine and cosine, are converted to digital square waves. The digital square waves are decoded to produce digital position quadrants, wherein each quadrant represents a specific motor position. The corresponding digital square waves are also decoded by a logic array device and coupled to the select input of an analog switch.

Abstract: In an apparatus for measuring texture and characterization of the surface of a sample on the basis of the drive signal of a servo control circuit by allowing a probe-tip (1) to approach the sample (2) and subjecting the probe-tip (1) to servo control so that a current, which is generated by moving the probe-tip (1) on the sample surface and which flows between the probe-tip (1) and the sample (2), becomes constant, the present invention discloses a surface metrological apparatus comprising a circuit (11, 12) for correcting the texture and characterization of the sample by use of a current error of the measured value of the current described above from the set current value.

Abstract: A driving system for driving a stepping motor to which the number of driving steps and a driving trigger are input to rotate the stepping motor by a half step so as to follow a one-two phase energization sequence. The system energizes one phase of the motor by a driving mode command to position a rotor, and the motor is then rotated by starting energization from two phases next to the one phase already energized.

Abstract: An integration-proportional controller in a servo-control system comprises in one aspect, an integrator for integrating a deviation of an input speed reference signal from a feedback signal fed back from an object to be controlled, and a proportional amplifier connected with the integrator for amplifying the feedback signal, the integrator including a clamping function in which an output value therefrom and an initial value for the next successive integration are changed, when the output value as a result of integration of the deviation is out of a predetermined proper output region, to the nearest boundary of the predetermined region value.

Abstract: The present invention discloses a method of loading a control program for a numerical control apparatus, wherein the control program is composed of a plurality of load modules. Each module contains a judgment codes, such as a version number, at the head portion thereof, and is stored in a read/write operation enabling memory, so that each of the judgment codes can be compared with a corresponding judgment code received from an external apparatus by a judgment code comparing means. When the comparison detects different judgment codes, transmission of the new load module corresponding to the discorded judgment codes requested by a modified load module requesting means. Only the substantive portion of the load modules corresponding to the discorded judgment codes received through the comparing means and requesting means need be loaded onto the memory by way of a load means.

Abstract: A position control system is disclosed for positioning a stepping motor to a target position according to a closed loop control system. The closed loop control system controls the position of the stepping motor according to a current position signal outputted from an encoder operatively coupled to the stepping motor. Furthermore, circuitry is provided for correcting electrically a torque angle error of the stepping motor caused by a positional error between the stepping motor and the encoder due to a mechanical mounting error of the encoder, to thereby drive the stepping motor at a torque angle maintained at the most desirable range.

Abstract: A microcomputer 1 servo controls a rotational speed of a capstan motor 10 in a VTR in a digital manner. A value of a timer counter 6 is stored in an ICR 7 at a timing of each edge of FG signal pulses generated as the capstan motor rotates. Thereafter, in the microcomputer 1, a FG interrupt processing is carried out corresponding to the value of ICR 7. More specifically, the microcomputer 1 alternately measures a first period from a rise of one pulse of the FG signal to a rise of a subsequent pulse thereof and a second period from a fall of one pulse to a fall of a subsequent pulse to determine an amplitude of a speed error signal based on these periods. Therefore, a sampling frequency for the digital servo control can be double that of a prior art.

Abstract: A band pass filter multiplies an input waveform with first trigonometric functions at a plurality of frequencies and then filters the products. Furthermore, with that filtering step, the products are multiplied, or their phase is changed by a predetermined value, and the results are multiplied by the inverse of the trigonometric functions.The sum of this, for all frequencies, generated a filtered output waveform. Where the input waveform has two components, the corresponding outputs can be obtained from the read and imaginary components of the output waveform. In practice the trigonometric functions are produced by sine and cosine components at each frequency. In this way a band pass filter device is formed which is suitable for use in the control system of an apparatus which must be controlled continuously, such as a control system for a rotor.

Abstract: A drive circuit excites a stepper motor. A current steering network alternately conducts current through first one and then the other of a set of AC windings. A regulated current source excites the DC windings of the stepper motor such that magnitude of the resultant vector due to the current in the motor is substantially constant in time.

Abstract: A motor feedback control system which in addition to a quantized digital position feedback value, uses a feedback signal which represents the error between the actual motor position and the quantized digital position. The error function is combined with the quantized digital position value to produce a digital position value with greater resolution. The combined value is differentiated to produce a velocity value for velocity feedback control of the motor.

Abstract: A control device for an industrial machine comprising a numerical control device and a programmable controller, the numerical control device comprising: a data processing section essentially comprising a memory and a central processing unit, for analyzing and operating input numerical data, outputs of the data processing section being used for performing numerical control of a machine to be controlled and of rotation of a spindle of the machine; a gear ratio data memory for storing gear ratio data of gears through which a spindle motor is coupled to a spindle head holding a tool, the gear ratio data being applied to the gear ratio data memory through a bus from the programmable controller adapted to perform sequence control of the machine; and synchronous operation controller for calculating actual speed of rotation of the tool through operation using the gear ratio data and a feedback signal of the spindle motor, and performing synchronous operation control of the tool and a feed shaft.

Abstract: Advanced digital motion control is a multi-axis incremental position control system which includes a digital processor and memory, servo motor actuator with tachometer feedback, velocity servo power amplifier, position feedback device, position feedback signal converter, and digital to analog converter. The processor provides digital time reference feedback control of motion profiling and positioning of the mechanical load for multi-axis simultaneously without sacrificing update feedback rate control. The read time code execution time is compact and speed efficient optimizing control of multi-axis high speed/high accuracy servo systems in a space and cost effective method.

Abstract: The invention comprises a voice coil motor for moving a head for reading information from or writing information to a disk, a driving circuit for supplying current to the voice coil motor in response to a first control signal and for changing the gain of the driving circuit in response to a second control signal. The gain of the driving circuit is increased during a moving control mode (i.e. a seek mode) and decreased during a position control mode (i.e. a track-following mode).

Abstract: A system for controlling the driving of a stepper motor which is rotated by the driving pulses generated based on the two-phase excitation system for rotating a driven system is disclosed herein comprises when the frequency of said driving pulses is outside of the resonance ranges of said stepper motor and some predetermined component parts of said driven system, respectively, the driving pulses generated based on said two-phase excitation system are applied to said stepper motor to rotate the same, but when the frequency of said driving pulses is within said resonance ranges, a brake pulse and a power suppression portion are added to said driving pulses so that said stepper motor is caused to rotate without causing resonance and can be stopped at a predetermined position with a high degree of accuracy and furthermore noise can be suppressed to a minimum.

Abstract: A numerical control device for a multi-axis lathe which is capable of controlling movements of a plurality of tools simultaneously. With the numerical control device, the movement of a first tool in a Z-axis direction is controlled according to the movement of a workpiece to be machined and the other movement of remaining tools in the Z-axis direction are controlled taking the Z-axis movement of the first tool into consideration, so that the different machining operations using different tools can be attained simultaneously or successively.