Abstract: A motor control for a treadmill has an improved, inexpensive, and simple set of power supplies, derived from the bus voltages of the DC busses with simple voltage dividers, to supply operational amplifiers connected to the positive DC voltage bus with a dual voltage supply and a common or neutral, and to provide a single voltage power supply connected to the negative bus for the driving circuitry of a motor energization switching controlling element. The dual power supply for the operational amplifiers comprises a voltage divider containing two, series connected zener diodes in series with a resistor. The one of the series connected zener diodes is connected to the positive DC voltage bus, and the resistor is connected to the negative DC voltage bus. A common connection between the two zener diodes becomes the neutral or common voltage for the operational amplifiers, and the zener diode voltages become the positive and negative supply voltages for the amplifiers.

Abstract: A digital current regulator for controlling the operation of an inductance device such as an AC motor. A plurality of independently controllable insulated gate bipolar transistors are selectively enabled to vary the instantaneous phase and magnitude of current applied to an AC motor. To minimize induced back EMFs during current switching operations, a number of safeguards are utilized. Switching between adjacent states only is provided to minimize the magnitude of instantaneous current changes. A "ready blocking" function limits the maximum switching frequency to avoid significantly derating the switching device capabilities, while a "time out" feature assures system operation above at least a minimum switching frequency to further minimize the magnitude of instantaneous current changes. A time hysteresis function is provided to avoid switching device response to false feedback control signals.

Abstract: A controlling apparatus for use in a balanced work or cargo handling system which aims at detecting the weight of the work or cargo suspended accurately even if a drift occurs in an acceleration detector due to changes in ambient temperature to thereby enable a stable work or cargo raising and lowering operation to be achieved. The controlling apparatus comprises an acceleration correcting arithmetic unit (23) adapted to output the difference between an averaged acceleration signal (Va.phi.) obtained by averaging the drifted acceleration signals (Va) transmitted by an acceleration; detector (8) during a predetermined period of time and the drifted acceleration signal (Va), as a corrected acceleration signal (Va') to a command arithmetic unit (17) and a load storage and arithmetic unit (22) when the absolute value (.vertline.Va.vertline.) of the drifted speed signal (Va) is less than a preset value (.epsilon.a) and the absolute value (.vertline.V.vertline.

Abstract: A direct current motor driving device for driving a direct current motor having a plus terminal and a minus terminal, which comprises a direct current source having a plus terminal and a minus terminal, the plus terminal being connected to the plus terminal of the direct current motor, pulse generating device for generating a pulse signal when an input signal to an input terminal of the pulse generating device exceeds a set threshold value, driving device for driving the direct current motor in response to the pulse signal outputted by the pulse generating means, and a first resistance type voltage dividing circuit inserted between the minus terminal of the direct current source and a minus terminal of the direct current motor for providing as the input signal to the pulse generating device a voltage signal produced by resistance-dividing a voltage between these terminals in a first ratio, whereby a counter electromotive force generated by the direct current motor by the rotation of the direct current motor b

Abstract: A method of synthesizing load invariant dc drive system comprising positive armature current feedback of exactly specified nature and value of its transfer function. The system transfer function independent of load is realized while stability and dynamics of the system are controlled by additional voltage loop.

Abstract: Control arrangement for an electric motor having a control arrangement which, in accordance with at least one nominal value fed thereto, controls at least one power control element to be connected to an electrical network and the motor, including data transmission apparatus in the form of a computer device for applying to the control arrangement data received by the computer device from at least one of a device for determining the data and a memory wherein the data are stored.

Abstract: A method of synthesizing drive systems, including dc, synchronous and asynchronous ac, and step motor drive systems, of instantaneous response and zero error in both transient and steady state with respect to an input command and of infinite disturbance rejection ratio with respect to a load torque changes, comprising an inner positive current feedback of exactly specified nature and value of its transfer function forcing the motor impedance to zero for load independence, and further comprising control functions in a direct path with respect to both position and velocity feedback loop and in a feedforward path of exactly specified values which, together with the inner positive current feedback loop, provide for the zero-dynamics system transfer function with respect to the command with an associated instantaneous response.

Abstract: In conventional disk shaped recording reproduction devices, vibrations have been absorbed by the up and down motion of protruding rods which are supported in a viscous liquid such as a silicon oil. According to this invention, an inexpensive elastic body is used, which is heated by a heater so that, by maintaining the temperature of the elastic body within a certain range, the deterioration of the vibration absorbing characteristics of the elastic body with temperature changes is considerably reduced and the elastic body can be made more compact.

Abstract: A method of synthesizing a system which forces finite value of an impedance to zero comprising a positive current feedback of a prescribed functionalism and a negative voltage feedback to ensure stability of the system. The prescribed functionalism of the current loop uses arithmetic elements as well as voltage and current measurements to provide for a parameter-free synthesis of the converter whereby the converter operates in the measurement-based mode, the measured variables being the voltage and the current associated with the impedance of interest, without a need to supply values of both resistive and reactive components of the impedance of interest. The converter is used in synthesizing electric motor drive systems, incorporating any kind of motor, of infinite disturbance rejection ratio and zero-order dynamics and without specifying the resistive and the inductive values of the motor impedance.

Abstract: A spindle motor stop control device applies a reverse torque braking force to the spindle motor to effect stopping of the motor. A speed detector detects when the number of rotation of the motor has slowed to 1/n of a predetermined number of rotation and issues a detection signal. The time period beginning with the application of the reverse torque braking force until the issuance of the detection signal is measured. Then, a time period t=T/(n-1) is calculated and the reverse torque braking force is continued for the time, t, and then removed.

Abstract: In a motor speed controll apparatus for a DC motor, there are provided a frequency signal generating circuit for outputting a signal at a time period corresponding to a rotation speed of a motor, a sawtooth wave output circuit for outputting a sawtooth wave, the voltage of which increases in a constant time-constant at said time period, a holding circuit for holding a substantially peak voltage of said sawtooth wave as a signal voltage corresponding to the rotation speed of the motor, a differential amplifier circuit for comparing said signal voltage with a speed setting voltage and for outputting a speed control signal in accordance with a difference in this comparison, said speed control signal being supplied to a motor drive apparatus, an amplifier circuit interposed between the output of said holding circuit and input of said differential amplifier circuit, and an operation control circuit for controlling said amplifier circuit to an operative mode and a non-operative mode selectively, the motor being dri

Abstract: A speed control apparatus for a motor comprising a motor model formed of a motor current model and a motor speed model connected in cascade, a basic torque instruction signal being applied to the motor model, and first and second control loops comparing output signals from the motor current model and the motor speed model with an instantaneous actual motor current signal and an instantaneous actual motor speed signal respectively and generating first and second correction signal to be added to the basic torque instruction signal to form a corrected torque instruction signal which is applied to a motor current control circuit, whereby a speed oscillation is suppressed even when the motor is driving an oscillatory load.

Abstract: A workpiece clamp actuator system which includes a clamping mechanism and an induction motor having an output coupled to the clamping mechanism for moving the mechanism between an unclamped position in abutment with a stop and a clamped position in abutment with a workpiece. A motor controller selectively feeds energy from first and second power supplies to the induction motor, the first power supply having an output voltage and frequency selected to obtain rapid initial motion at the clamp, and the second power supply having an output frequency equal to the slip frequency of the motor at rated torque and an output voltage selected to provide full load current, and thus maximum torque, at both the clamped and unclamped positions.

Abstract: A motion control system for a reel to reel web transport apparatus which maintains a controlled tension on a web as it is transported between reels. The motion control system includes brushless direct current motors directly coupled each reel. A magnetic hysteresis brake is coupled to each reel by means of respective one-way clutches. During transport of the web from reel to reel, a magnetic hysteresis brake applies a controlled torque only to the reel supplying web. Thus, a controlled tension is maintained on the web at all times, even during loss of power to the DC motors.

Abstract: The present invention relates to a method of restoring a rotary axis to a reference point. A workpiece coordinate system serving as a programming reference with respect to a machine coordinate system is decided, numerical control (NC) program data are created including at least NC data specifying an angle r between an origin (WR) of the workpiece coordinate system and a reference point (MR) in the machine coordinate system, and rotational direction positioning data based on the workpiece coordinate system, and a rotary axis is positionally controlled based on the NC program data. The method includes updating present positions Pm, Pw of a fixed point Q on a rotary axis (11) in the machine coordinate system and workpiece coordinate system in dependence upon rotation of the rotary axis, obtaining an angle a that satisfies the equationsPm=360.multidot.n+a, Pw=360.multidot.n+a-rin response to a reference point restoration command, then rotating the rotary axis by .vertline.a.vertline..sup.

Abstract: The trajectory of an electromagnetic actuator is adjusted by pulse-width-modulating feedback control of the waveform which energizes the coil. As applied to actuators for impact printing, the objectives of the control scheme are to regulate the armature's time of flight and its velocity at impact, in spite of disturbances, thereby to provide higher-quality printing at increased speed. Each actuation is produced by energizing the coil with a series of pulses. Regulation is accomplished under microprocessor control by measuring the state variables of the system--armature position, armature velocity, and coil current--at the beginning of each pulse, comparing these measurements to ideal values, and modulating the width of the pulse as a function of the errors. In general, the appropriate functional relationship between the measured errors and the pulse-width modulation is nonlinear, and is different for each pulse in the series. Systematic means for determining these relationships are given.

Abstract: A PLL motor controller in accordance with the present invention comprises a driving system for driving a motor, a reference frequency generator for generating pulses with reference frequency that corresponds to the speed of motor rotation to be set, a counter which is run freely at the reference frequency from the reference frequency generator, a pulse generator for generating sampling pulses with a timing that responds to the actual rotation speed of the motor based on the pickup signal from the driving system, a latch circuit for latching a digital information in the counter at the timing of sending the sampling pulses from the pulse generator, and a D/A converter for analog-converting the digital information in the counter that is latched and for supplying the result to the driving system. The driving system is constructed so as to drive the motor to be rotated with a set speed of rotation according to the error signal from the D/A converter.

Abstract: Electric control apparatus (20) for equipment (1) comprising a driving circuit (5) for generating a signal (S.sub.1) to drive the equipment as installed in a vehicle, the driving circuit including circuitry having a first specified working voltage range, and a breaking circuit (6) operatively interposed between the driving circuit and the equipment, the breaking circuit including a first switching circuit (100) for operatively interrupting the supply of the drive signal to the equipment under a condition that the supply voltage (Vdd) is lowered below a first predetermined level (V.sub.

Abstract: A method and apparatus are provided for monitoring the surface level of a liquid, such as molten metal, by moving first and second sensing electrodes vertically with respect to the surface level of the liquid, positioning the lower portion of the second electrode vertically displaced upwardly with respect to the lower portion of the first electrode, such that the amount of vertical displacement is directly related to the accuracy of determining the liquid level, generating an electrical signal as a function of each electrode position, then moving the first and second electrode vertically with respect to the surface level of the liquid in response to the electrical signal corresponding to each electrode, and thereafter determining the liquid level when the first electrode is in contact with the liquid and the second electrode is in noncontacting position above the liquid.

Abstract: A robot path error correction system is provided for driving and controlling a movable element in a designated direction. The system includes a sensing device for sensing a remaining amount of command pulses at deceleration of the movable element; timing deciding device for specifying start timing of a pulse distribution calculation along a subsequent travel path in dependence upon the sensed amount of command pulses remaining; and an adding device for adding command pulses which accelerate the feedrate and command pulses which decelerate the feedrate in accordance with a commanded velocity and commanded position at the specified timing.