Abstract: A driving apparatus for a stepping motor with a rotor and a plurality of windings, adapted for reduction of fluctuation of the rotor, comprises a driver responsive to drive control data for selectively driving each of said plurality of windings, a current controller responsive to current control data for controlling a driving current applied to the stepping motor, and a controller responsive to a rotation command for generating and applying the current control data and the drive control data to the current controller and the driver, respectively.

Abstract: A drive apparatus is disclosed which is designed to switch/excite a plurality of excitation windings of a stepping motor in a predetermined order. Periodic velocity fluctuation data of the stepping motor is stored in a memory unit in advance. An arithmetic unit reads out the velocity fluctuation data stored in the memory unit. The arithmetic unit outputs a pulse train whose pulse rate fluctuates to have a phase opposite to that of velocity fluctuation obtained from the velocity fluctuation data. This pulse train is used as switching timing signals for switching/exciting the plurality of excitation windings in a predetermined order.

Abstract: A digital controller comprising a deviation calculator, a positional P-controlling calculation device, a velocity-type I-controlling calculation device, a signal converter, and an adder unit. The deviation calculator for subtracts a process variable of an object from a set point variable, to obtain a deviation. The positional P-controlling calculation device performs positional P-calculation on the deviation obtained by the deviation calculator. The velocity-type I-controlling calculation device performs velocity-type I-calculation on the deviation. The signal-converting device converts the velocity-type I-calculation output of the velocity-type I-controlling algorithm device, into a positional I-signal. The adder unit adds the positional I-signal obtained by the signal-converting device and the positional P-calculation output obtained by the positional P-controlling algorithm device, thereby obtaining a manipulative variable. The manipulative variable value is supplied to the object to control the object.

Abstract: An acceleration/deceleration control apparatus for servo control is provided, which is capable of securely restraining vibration of servomotors for use as drive sources for various machines.The acceleration/deceleration control apparatus comprises acceleration/deceleration control sections as many as servomotors mounted in a machine, and each acceleration/deceleration control section includes first to third acceleration/deceleration filters each composed of a predetermined number of delay units and connected in series with one another. The first to third filters deliver outputs (Pb, Pc, Pd) to a corresponding one of the second and third filters and a servo circuit, each of the outputs being obtained by dividing the sum of stored values of the delay units of each filter and a corresponding one of a commanded speed (Pa), a first output (Pb) and a second filter output (Pc) by the sum of a value of "1" and the number of units.

Abstract: The motor drive circuit has an instrumentation amplifier with a programmable gain set by selectively blowing fuses during initial circuit calibration. The quasi-sawtooth waveform of a relaxation oscillator is compared with the amplified and conditioned signal produced by a pressure responsive Wheatstone bridge circuit. The result of this comparison is a drive signal which controls the pump motor speed. Radio frequency interference is minimized by storing the motor drive current in a capacitor located near the motor. Further interference is minimized by a reactive matching circuit which combines with the motor impedance to result in a purely resistive load.

Abstract: A detection apparatus is provided which is capable of detecting an excessive position error in a servo system in an appropriate manner over a wide servomotor rotational rate region, so as to accurately and immediately determine an overload state of a servomotor and the like. A permissible maximum value of the position error is obtained by first obtaining a product of a proportional coefficient set beforehand and a maximum value of pulse distribution amounts--a number of movement command pulses distributed from a central processing unit of a numerical control unit. The pulse distribution amounts are respectively stored in a table provided in a memory. The product is then, second, divided by a position loop gain. The central processing unit then determine that an excessive position error has occurred when an actual position error read from an axis controller is greater than or equal to the permissible maximum value.

Abstract: A method and device for smoothly rotating a diffraction grating in a spectrophotometer by means of a galvanometer includes modifications in the software in the microprocessor which controls the galvanometer. The software modifications cause the galvanometer to rotate the grating in a series of discrete steps that stimulate a smooth minimum jerk rotation. The amount of rotation in each discrete step is calculated by the microprocessor.

Abstract: A step motor control device for controlling a performance of a step motor by outputting a plurality of phase of pulses, having a keyboard for inputting a number of steps for the performance of the step motor, is capable of determining an interval of time for outputting the pulses according to the number of steps inputted through the keyboard, and outputting the pulses in response with the interval determined by the determining means.

Abstract: A drive device for a reciprocating part having a part which is connected to a stepping motor whose direction of rotation can be changed. The stepping motor is reciprocatingly actuated in a single step length between no more than two step positions, such that it is possible to move the reciprocating part backwards and forwards in a predetermined manner in a simple and reliable way.

Abstract: In a control (100) for a variable displacement hydraulic motor (12) having an electrically controlled hydraulic servo valve (14) for controlling the displacement of a hydraulic motor by varying position of a wobbler (28) in response to a servo valve control signal, a velocity transducer (72), coupled to a shaft (30) driven by the motor, for providing a velocity signal representative of the velocity of the shaft, and a wobbler position sensor (84), coupled to the wobbler, for producing a wobbler position signal indicative of the position of the wobbler, an improvement in accordance with the invention includes a controller (100) for producing the servo valve control signal as a function of a wobbler position command specifying a position of the wobbler wherein the wobbler position command is a function of at least one of the velocity signal representative of the velocity of the shaft and the wobbler position signal.

Abstract: The total periodically induced vibratory disturbance in a structure having unique structural characteristics is minimized. Actuators are operated in response to complex input signals to produce counteractive forces in the structure. Sensors responsive to the vibrational disturbance and the counteractive forces produce outputs indicative thereof. A processor having an electrical characteristic related to the structural characteristic produces complex outputs for each actuator in response to the sensor inputs. The complex outputs are adjusted by the processor to result in a convergence of the structural response to the minimum vibration in response to the disturbance and the actuator inputs.

Abstract: A stepping motor unit includes a stepping motor of the type wherein the interior of the stepping motor is filled with an oil, a detector for detecting the temperature of the oil in the stepping motor, a device for varying an upper limiting value of the rotational speed of the stepping motor and an upper limiting value of the rotational acceleration of the stepping motor in view of a current viscous condition of the oil based on the temperature detected by the temperature detector, and a driver for driving the stepping motor at a rotational speed and a rotational acceleration which fall in ranges, respectively, not exceeding the upper limiting values. The stepping motor unit thus constructed has rapid and accurate response characteristics and is capable of operating reliably without falling out of step even when the environmental temperature varies in a very wide range. A rotary control valve incorporating such stepping motor unit is also disclosed.

Abstract: A method of correcting a machining program for a numerical control device during an execution of the program is provided. A created machining program, which is stored in a memory (5), is executed for a program check, a single block stop is effected at a portion (2) at which an error is found in the machining program, and the machining program is executed in reverse to a predetermined block (P1). Then the machining program is corrected and executed. Accordingly, it is not necessary to return to the beginning of the machining program for a reexecution thereof, and thus the machining program can be efficiently corrected.

Abstract: A drive circuit for a stepping motor which seeks the read/write head of an FDD or the like to a predetermined track. The drive circuit includes a plurality of exciting coils for providing exciting fields to a rotor and supplies exciting currents in the forward or reverse direction by a predetermined combination to each of the exciting coils. A constant-current circuit is provided so as to cause the exciting current flowing on each exciting coil to have a constant value. The constant-current circuit includes a current mirror circuit with the slave branch connected to the exciting coils and the master branch contained in the constant-current circuit. The constant-current circuit further includes a constant-current source for supplying a constant current to the master branch of the current mirror circuit and a constant-current setting circuit for setting the constant current as desired.

Abstract: A servo motor control apparatus effecting a feedback control of a servo motor according to an external operation command. The apparatus includes: an operational running state detecting unit for detecting a running state of the servo motor; a memory unit in which data representing inter-relation values are stored; a current value computing unit for computing an appropriate drive current value for the external operation comand; and a driving unit for driving the servo motor according to the computed appropriate drive current value.

Abstract: A system (11) for monitoring and controlling the movement of a mass (12) along a predetermined path (14) by a motor-driven flexible member (20) is provided to modulate the motor drive output so that the actual velocity of the mass corresponds more closely to the desired target velocity profile. The system preferably employs a dual loop servo system wherein an outer servo loop uses conventional linear encoding techniques and is supplemented by an inner servo loop utilizing a sensor (27) that detects a physical characteristic of the flexible member representative of the relative velocity of the mass. Relative velocity transducers utilizing magnetic circuits and operating according to variable reluctance principles for generating relative mass velocity signals directly are disclosed.

Abstract: A voltage control device for controlling a driving voltage applied to a motor having a plurality of phases is provided with a switching circuit for changing the motor driving voltage from one voltage value over to another among a plurality of voltage values. The switching circuit is arranged to have a stop phase of the motor excited by a lower driving voltage than a rotation driving voltage in adjusting the stop phase at which the motor has been stopped.

Abstract: A motor controller provides a digital monostable circuit which generates a control signal indicating whether a field coil within a motor should be turned on or off. Two registers are provided within the digital monostable to store values indicating a fixed off time and a minimum on time. These registers can be loaded with selected values by a microprocessor or other controller. The stored values are selectively loaded into a counter which, when the field coil current reaches a preselected level, turns the supply to the field coil off for a time corresponding to the off time value, then on again for a period at least as long as the minimum on time value. The values in the off time and minimum on time registers can be changed to suit operating conditions of the system, and the controller can be operated in either PWM or open loop mode.

Abstract: In a method and circuit for operating a stepping motor having several windings, and wherein a movement of the stepping motor induces a voltage in a winding which is not required at the time for generating a propulsive force, the induced voltage is evaluated. After the stepping motor is connected, the stepping motor is operated in a predetermined direction, whereupon a stopping of the stepping motor is detected by the absence of the induced voltage. A memory containing the instantaneous position of the stepping motor is then set to a predetermined value.

Abstract: A drive circuit for a stepping motor used for seeking the reading/writing head of a floppy disk or the like. The stepping motor is smoothly driven by inserting an inner step pulse between the input step pulses when excitation signals are supplied to the stepping motor on the basis of the step pulses from the host computer. Since the interval between the step pulses output from the host computer is different each time, the interval between the step pulses is measured and the timing for generating an inner step pulse is determined on the basis of the measured value.