Abstract: A self-commissioning controller 7 for a field-oriented elevator motor controller 14 includes calculating an integral gain K.sub.I, a proportional gain Kp, and an overall gain (Gc) for the motor controller; obtaining initial values of a rotor time constant .tau..sub.R, magnetizing current Id, and motor torque constant K.sub.T for the motor controller 14, and obtaining a value of a motor transient inductance L.sigma.; calculating final values for said rotor time constant .tau..sub.R and magnetizing current Id, using said transient inductance L.sigma.; and calculating a system inertia J* parameter for speed loop compensation 16 within the motor controller 14. The controller 7 may also include calculating the initial values for .tau..sub.R, Id, and K.sub.T *, and performing self-commissioning automatically upon receiving a command from a service tool 80.

Abstract: A throttle valve controller achieves high output response to the smaller deviation of the actual opening from the demand opening of the throttle valve and achieves high control stability against the larger deviation. It has a preset data table containing proportional gain values and integral gain values of PID control in correspondence to deviation values in inversely proportional arrangement. During the transitional state of control system, a pair of provisional gain values are read out of the table in response to the deviation value: (step S3), these gain values are compared with those of the previous operation cycle and the smaller gain value pair are selected: (steps S4-S7), and the valve drive signal is calculated from the selected gain values:(steps S8, S11). Consequently, the controller achieves high output response to the smaller deviation due to the larger gain value and high control stability without the overshooting of valve movement against the larger deviation due to the smaller gain value.

Abstract: A device for outputting a suitable rotation torque relative to a load torque or actual torque exerted on a stepper-motor when the stepper-motor is used as a drive of an image processing device. The output torque of the stepper-motor depends on a supply current to the stepper-motor. CPU determines a suitable supply current using a table in ROM so that the stepper-motor is able to rotate at an optimum rotation torque. To this end, CPU sends a particular signal to the motor driver so that an appropriate supply current is supplied to the excitation phases A/B of the stepper-motor. The CPU determines the load torque based on an integrated current fed to the stepper-motor during a particular period. The CPU calculates difference between the load torque and rotation torque and determines the signal to be applied to the motor driver based on the torque difference.

Abstract: A motor speed controller which detects the position y(i-k) of a motor at the time K.multidot.Ts (k.gtoreq.0, Ts: sampling period) ago from the present time (i) and feedback-controls the speed of the motor by using a motor speed feedback signal Vfb calculated based on the detection signal is provided with a means which calculates a torque command u(i) from a speed command and the motor speed feedback signal vfb, means which calculates the speed v(i-k) from the position y(i-k), means which stores the values of the speed v(i-m) (m=k, . . . , M') from M' sampling periods before to the time i-K, a predictor which predicts the speed prediction value v*(i+m) (m=-K+1, . . . , M) at the times up to M sampling periods after from the dynamic characteristic model of the motor, the torque command u(i), and the position y(i-K), and means which finds the speed feedback signal from formula: ##EQU1## where Wm and W'm represent weight factors.

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 speed control apparatus for a rotary motor includes a motor for rotating at a speed based on a torque command and which outputs a present angular position and a present angular speed of the motor. A speed measuring unit is provided for obtaining a speed error representing the difference between a reference angular speed and a present angular speed. A speed controller is provided for outputting a current command for controlling a rotational speed of the motor. A learning compensator is provided for correcting an effect of a disturbance expressed as a function of an angular position and an angular speed applied to the motor, via a repetitive learning process using the reference angular speed, any one of the speed error from the speed measuring unit and the current command output from the speed controller and the present angular position of the motor, for removing a high frequency noise generated in the repetitive learning process, and for outputting a resultant disturbance correction value.

Abstract: A servo control system is presented that provides improved bandwidth. The improved bandwidth is achieved by dividing the differential portion of the servo control system into two components. One of the differential components experiences no delay thus improving the servo control system response. The differential component that experiences no delay is combined with the proportional portion of the control system and implemented as an analog circuit. The hybrid analog/digital loop compensation circuit provides even better response time as the analog circuit provides near instantaneous responses to changes in input.

Abstract: In a method for controlling an electric motor the stator voltage frequency of the motor is determined by adding the optimal slip frequency of the motor and the desired rotational frequency of the rotor. The magnitude of the stator voltage is determined by subtracting the actual rotational frequency and the desired rotational frequency of the rotor. The desired stator frequency and magnitude are inputted into a pulse width modulation unit which controls an inverter to supply the appropriate voltages to the motor. The operation of the motor with optimal slip has the advantage that the efficiency is optimal independent of the load.

Abstract: A digital locked loop uses feedback to maintain an output digital signal in a specific digital relationship with a reference digital signal. The digital locked loop can lock an input digital signal according to a reference digital signal by using a digital counter, a resister and an arithmetic logic circuit instead of a phase locked loop and a frequency locked loop in motor drive integrated circuit for permanent magnetic brushless DC multi-phase motor drive applications. The circuit is designed not to use a voltage-controlled oscillator VCO and can be extended to broader applications such as digital data communications, digital image processing, and in the multi-media industry.

Abstract: In the digital PID (P:proportional, I:integral, D:derivative) control apparatus of the present invention, in which a deviation is obtained from a controlling amount of an object to be controlled, and a target value, a velocity type PI control operation is carried out on the deviation, a velocity type D control operation is carried out on the deviation or the controlling amount, these velocity type control operation outputs are synthesized, and then converted into a position type manipulation signal, and this signal is supplied to the object to be controlled, the derivation processing unit includes the judgment unit for judging whether K=2.multidot..DELTA.t/(.DELTA.t+2.eta..multidot.TD).ltoreq.1, or K>1 by using a control operation period .DELTA.t, a derivative time TD and a derivative gain 1/.eta., and the operation unit which carries out a lagged derivative operation by a bilinear transfer method when K.ltoreq.1, or carries out an exact derivative operation when K>1.

Abstract: A motor control apparatus comprises a speed command signal generating section generating a speed command signal for accelerating or decelerating a control object in accordance with a predetermined pattern. A position control section controls the position of the control object and a speed control section controls the speed of the control object by accelerating or decelerating the control object in accordance with the speed pattern. An encoder observes the present position of the control object. The load inertia of the control object is identified based on a positional deviation between the command position of the control object and the present position obtainable from the encoder at the time the speed command generated from the speed command signal generating means becomes a predetermined speed.

Abstract: A velocity control method for use in a servo motor having a disturbance eliminator is described. The velocity control method includes the steps of calculating a control torque input value based on a desired target velocity input value and an output velocity value of an actual mechanical model, adding a disturbance torque value to the control torque input value to input the added result to the mechanical model, inputting the control torque input value to a virtual model to calculate an estimation velocity according to the control torque input value, calculating a corrected torque based on a velocity value difference between the output velocity value of the mechanical model and the estimation velocity value of the virtual model, and reflecting the corrected torque on the control torque input value. Accordingly, although unknown disturbances are input to the control system, a velocity error can be conversed into zero as closely as possible to enable an accurate velocity control.

Abstract: A method and apparatus for controlling a hydraulic manipulator defines a position error signal (.theta..sub.e), defining a first control signal (U.sub.P, U.sub.PD) based on the position error (.theta..sub.e) and generating an improved position error integral signal (.theta..sub.I) based on a product of the position error (.theta..sub.e) integral signal and a velocity factor F.sub.V. The velocity factor F.sub.V is based on a derivative of the position error (.theta..sub.e) and a nonlinear function. An integral control signal (U.sub.I) is produced based on the improved position error integral signal (.theta..sub.I) and is combined with the first signal (U.sub.P, U.sub.PD) to provide an output control signal U to control the manipulator. The invention also preferably includes a system to further reduce overshoot by further modifying the position error signal (.theta..sub.

Abstract: A motor drive having a very large dynamic speed range comprises a PID position feedback control system (8) in which the motor position is readjusted on the basis of the difference between the instantaneous (x.sub.a) and the nominal (x.sub.s) position. A series of nominal positions (x.sub.s) is determined from a nominal speed (v) in a speed control unit (5). The successive nominal positions (x.sub.s (t)) in a series exhibit a constant difference (.DELTA.x) relative to one another and are presented to the PID position feedback control system (8) with fixed intervals (.DELTA.t). A drive of this kind is used, for example in the beam collimator of an X-ray device.

Abstract: A PID controller roughly controls several times of trial operations preceding an actual operation. A trial operation analyzing unit analyzes and learns the trial operations conducted under the control of the PID controller, thereby generating a criterial manipulated pattern that serves as a criterion of a time-series pattern of a manipulated variable in the actual operation. An actual operation controller controls the actual operation on the basis of the criterial manipulated pattern thus generated. An operation changeover switch changes over between the PID controller to the actual operation controller in accordance with the state of operation, i.e., the trial operation or actual operation. Thus, the control apparatus itself learns the trial operations, and can self-acquire the criterial manipulated pattern for the actual operation. That is, a suitable criterial manipulated pattern can be generated easily.

Abstract: A servo system adjusting method for an integration-proportional differentiation type compensation system for generating a control input by summing an integration of a control error, a controlled amount which is an output of an object to be controlled and a differentiation thereof, multiplied by predetermined coefficients, respectively, for the object to be controlled having a double integration type characteristic in a low frequency band, comprises a step of changing any of a feedback gain F.sub.1 of differentiation of the controlled amount, a feedback gain F.sub.2 of the controlled amount and a gain H of integration of the control error, and a step of determining other gains based on the changed gain value and the formulas;F.sub.1 /F.sub.2 =a*H/F.sub.2F.sub.1 =b*(F.sub.1 /F.sub.2)/Kwhere2.ltoreq.a.ltoreq.3,1.5.ltoreq.bK is a gain of the object to be controlled.

Abstract: Electronics for use in Coriolis and other sensors for reducing errors in the sensor output signal. An off-frequency drive scheme includes a frequency translation circuit in the excitation feedback loop of a sensor system to suppress components of the sensor drive signal at a predetermined frequency so that coupling of the drive signal to the sensor output signal can be readily removed by conventional filtering techniques. An amplifier circuit having a bandpass circuit in cascade with the forward loop gain is provided, with the bandpass circuit having a transfer function approximating one plus a bandpass characteristic, the passband of which corresponds to the information band. This arrangement increases the open-loop gain of the amplifier circuit around the information frequency without affecting the open-loop gain at DC and crossover so as to reduce phase and gain errors around the information frequency. A quadrature nulling system is provided for an in-plane micromechanical gyroscope.

Abstract: A velocity control method for a rotary motor and an apparatus adopting the same estimates and corrects a disturbance applied to the rotary motor to improve a velocity control characteristic. The disturbance is expressed as a function of an angular velocity and an angular position via a simple calculation process. The velocity control apparatus includes a learning compensator for receiving a velocity command, angular position information and the output of a velocity controller and correcting an effect of the disturbance which is expressed as a function of the angular velocity and the angular position, in addition to a general velocity control loop of a rotary motor composed of a velocity controller, a current controller, a motor and a velocity measuring unit. The learning compensator stores one period of the output of the velocity controller at a steady state of the velocity control loop and obtains a correction value using the stored value and the previous output value.

Abstract: A control method of a servomotor, such that a moving command for position-velocity processing, which is executed in every sampling period obtained by dividing a distribution period of moving commands into N units of equal parts, is determined from the above described moving commands of the distribution period. A velocity compensatory component is obtained on the basis of a moving command in a distribution period preceding by one period the present distribution period and is added to a velocity command, and an acceleration compensatory component obtained on the basis of a moving command preceding the time of the present position-velocity loop processing is added to a torque command, so that the phase of acceleration compensatory data is advanced from that of velocity compensatory data in feedforward operations.

Abstract: A control method capable of preventing vibration of a control object and making a band sufficiently high in controlling a robot or a machine tool in semi-closed loop. A torque command u" is obtained by executing a feedback-control of the servomotor using the position and speed of a servomotor in the same manner as in the conventional method. A displacement amount d1 between the motor position and the position of the control object and a displacement speed d2 are estimated by an observer. A corrected torque command u is determined by subtracting, from the torque command u", values obtained by multiplying the displacement amount d1 and the displacement speed d2 by the adjustable gains (.alpha.-KpK1) and (.beta.-K1), respectively. The servomotor is driven based on the corrected torque command u thus obtained. There can be obtained effects equivalent to those that would be obtained when a feedback-control is performed using the position and speed of the control object. The adjustment values .alpha. and .beta.

Abstract: A system for controlling a brushless DC motor which can minimize a torque ripple of a motor, thus reducing minute vibrations of the motor and loading devices and increasing efficiency. The system includes a current command generator for producing a current command signal by multiplying a wave form of the current command signal in correspondence to position information by the desired size of the current command signal; a current controller for controlling actual current in the motor to follow the current command signal produced from the current command generator, in response to a feedback error control signal having proportion, integral, and differential elements, and producing a signal for turning ON/OFF following the current command; and an inverter circuit for controlling switching elements to be turned ON/OFF by the signal produced from the current controller, and the desired amount of current to be applied to three-phase coils by a power supply unit.

Abstract: A robot control system generates an offset signal which is added to the control signal for a robot when the velocity error is small. The offset signal is, in each case, based on a previous offset signal added to the then current robot control signal which is updated regularly on discrete increments of time when the velocity error is small. Thus, with the control system when the velocity error is low adds the control signal to the then current offset signal to provide a corrected signal to control the robot. When the velocity error signal is high, the generation and addition of the offset signal is disabled.

Abstract: An improved method and apparatus for handling saturation conditions in the digital compensator of a control system. A clipping limiter is incorporated in the digital compensator for outputting both a limited signal to be sent to the actuator, and for outputting a clipping signal indicative of a difference between the input and the output of the clipping limiter. The clipping signal is delayed by one sample period, and fed back to the input to the compensator in order to provide a correct amount of compensation when the system is operating at or near saturation.

Abstract: A servo system for controlling the position of a read/write head over a rotating data disk is disclosed. The servo system includes the addition of a compensation scheme to the feedback loop that causes the open loop gain of the servo to increase only in a very narrow spectrum of its operating bandwidth. In a preferred embodiment, the compensation takes the form of a second order digital filter combined with a proportional-integral-differential phase compensation filter in the feedback loop of an embedded servo system for a digital data disk drive.

Abstract: A feedback control system which uses estimated back electromotive force(EMF) from a controlled actuator to provide feedback into the control system and improve control of the actuator. Back EMF is estimated from current through the actuator and voltage across the actuator. The estimated back EMF signal is fed back into the control system where it serves as a rate term. In the preferred embodiment the back EMF signal is used in combination with an actuator position signal which is also feedback into the control system. A complementary filter conditions both the rate and position signals for improved performance. The invention is particularly suited for controlling linear actuators which do not provide conventional rate feedback signals.

Abstract: A compressor control system for a commercial refrigeration system includes a variable speed compressor and multiple fixed speed compressors. The control system calculates a variable which fluctuates according to the desired capacity of the system and is calculated as a function of the difference between a variable indicative of the refrigeration load on the system, such as compressor suction pressure, and a target value. A "PID" proportional-integral-differential (PID) controller is used in which terms have been added which fluctuate as a function of the square of the difference between the sensed variable and the target value and as a function of the second derivative of the control variable with respect to time. Fixed speed compressors are turned on or off and the speed of the variable speed compressor is adjusted to bring the actual refrigeration capacity of the system in line with the system refrigeration requirements.

Abstract: A robotic arm is driven by a servomotor which is controlled through position and speed control loops. The position and speed control loops are adaptable in response to a flexible position control. Upon receipt of a flexible control command, a position gain and a proportional gain of the speed control loop are lowered in accordance with a set degree of flexibility. The output of an integrator of the speed control loop is also limited to a set clamp value. As a result, a torque command for controlling the servomotor never achieves an expressly large value even if a position deviation increases. In case an obstacle is placed in the transfer path of the robotic arm, the arm can be moved by human power to avoid the obstacle.

Abstract: A position control system which includes a plurality of actuators for moving an object, a plurality of sensors for detecting the state of the object, a first circuit for extracting a state signal, in each of different kinetic modes related to the object, from outputs of the sensors, a compensating circuit for compensating for the state signals in the respective kinetic modes, a second circuit for distributing an output of the compensating circuit and for providing drive signals for the actuators in accordance therewith, and a driver for driving the actuators in response to the drive signals.

Abstract: A redundant active hand controller system has first and second motors connected to a common shaft. A compensator which differentiates a motor command signal from a first proportional and integral controller, differentiates a motor command signal from a second proportional and integral controller and subtracts the first differentiated motor command signal from the second differentiated motor command signal to provide a correction signal. The correction signal is summed with the error signal into the first proportional and integral controller to correct for slight differences in the integral control function of the first and second proportional and integral controllers.

Abstract: A controller for controlling a non-linear mechanical system having a plurality of degrees of freedom, comprises compensation means to compensate the non-linear behavior of the mechanical system, the controller further comprises a reference model of both a control unit and the linearized mechanical system, and the controller further comprises adaptation means which adapts the compensation means in dependence on a difference between an output signal of the mechanical system and an output signal of the reference model.

Abstract: The present invention relates to a method and a device for executing phase compensation in a control system of a motor-driven vehicle, in which the time derivative for an output signal (y) from a circuit (1) contained in the control system is limited relative to the time derivative for an input signal (u) to the circuit (1) if the time derivative for the input signal (u) exceeds a predetermined value. A difference signal (.epsilon.) is formed between the output signal (y) and a signal (x) present in the circuit (1), the time derivative of which is not limited in relation to the time derivative for the input signal (u). The difference signal (.epsilon.) is filtered via an asymptotically stable filter (3) to form a signal (.delta.), which is fed back and added to the input signal (u) of the circuit (1) to form the signal (x). A conventional rate limiter may be used to form the output signal (y) from the signal (x).

Abstract: A method and apparatus for incorporating fuzzy logic into a feedback controller is provided. An error signal and the derivative of feedback or error is provided to the fuzzy logic to develop a proportional and differential signal, the differential signal is subsequently integrated and added to the proportional signal to create a control output of the controller. The fuzzy rules of the fuzzy logic decrease the integral term under situations that might lead to "wind-up".

Abstract: A method and apparatus for motor control tuning wherein an extremely accurate estimate of inertia is determined by using the second derivative of a desired motor velocity and the torque supplied to a motor is altered as a function of inertia.

Abstract: A method for accurately detecting an abnormal load caused, e.g., by adhesion of the distal end of a spot gun. A flag F2 is set to "1" when a move command is outputted to move a movable part of a machine and is reset to "0" upon lapse of a predetermined very short period of time, and, while the flag F2 remains "0" during stoppage of the movable part, a disturbance torque T0, estimated by a disturbance estimation observer, is stored and successively updated. When a move command is thereafter outputted, and the flag F2 is set to "1", an estimated disturbance torque T1 is obtained, and if the absolute value .vertline.T1-T0.vertline. of the difference between the disturbance torque T1 and the disturbance torque T0, estimated immediately before the movable part is moved, is greater than a reference value Ts, it is determined that an abnormal load is applied, whereupon an alarm is outputted, a flag F1 is set to "1", and the motion is stopped.

Abstract: The shift quality of an automated mechanical transmission is improved and transmission wear is reduced by controlling the armature current of the motor driving the transmission shifting mechanism. The current is monitored by a microcontroller to determine if the shifting mechanism has encountered a snag or has stalled during a shift operation. The microcontroller is programmed to control the duty cycle of a pulse width modulated (PWM) voltage signal, applied to the motor, in accordance with an algorithm which provides both proportional and derivative control of the error between the measured current and a target current. The rapid reduction in current spikes through PWM control reduces the force applied to the shifting mechanism and thus the sliding clutch and transmission gearing.

Abstract: An adjustment device for adjusting a plurality of control parameters used for controlling a servo motor according to the present invention includes: a first correction unit for correcting at least one of the plurality of control parameters; a calculation unit for calculating a change rate, due to the correction, of the at least one control parameter corrected by the first correction unit; and a second correction unit for correcting, based on the calculated change rate, the control parameters except the at least one control parameter corrected by the first correction unit, the adjustment device constituting a control system for the servo motor along with the servo motor.

Abstract: An electric motor control system compensates torque ripples to control the rotation of an electric motor more accurately. Compensated current amplitudes corresponding to the torques, speeds and rotational positions in the electric motor are stored in a memory 61. Address setting unit 91 prepares a read address AD.sub.1 in the memory 61 from the torque command T, speed information VL and rotational motor position P. The prepared read address AD.sub.1 is then used to read a torque error compensation data MD.sub.1 from the memory 61. An adder 12 adds the torque error compensation data MD.sub.1 thus prepared to the torque command T to determine current amplitudes AM in the electric motor. Three-phase current setting unit 10 sets three-phase AC current commands CU, CV and CW based on the current amplitudes AM and rotational motor position P. Thus, the rotation of the electric motor can be accurately controlled.

Abstract: A torque oscillation compensation system and torque estimator that uses torque emulator/observer feedback derived from an electric vehicle motor drive train. The present torque oscillation compensation system is adapted for use with an electric vehicle comprising a source of torque command signals and an electric motor that is controlled by a power switching circuit. The power switching circuit is responsive to the torque command signals and provides pulse width modulated signals for driving the motor. The system comprises a torque estimator that is coupled to received pulse width modulated signals provided by the power switching circuit, and motor currents and speed, for providing estimated torque feedback signals derived therefrom.

Abstract: The present invention provides an adaptive sliding mode control method capable of not only improving the convergence of estimated parameters but also providing outstanding vibration-damping properties. In this method, a position deviation .epsilon. between a command position and a motor position, a speed deviation .epsilon., and a position command acceleration .theta.r are determined. The difference .epsilon.t between the motor position and the position of machine's moving part and a differential .epsilon.t based thereon are obtained by observer processing and filtering processing. A phase plane Suf of the motor is obtained by feeding back the deviation .epsilon.t between the motor position and the position of the machine's moving part. Estimated values Jhat, Ahat and Grhat, representing an inertia term, coefficient of dynamic friction, and gravity term respectively, are obtained. A switching input .tau.

Abstract: A position control device for a servomotor in use of a NC machine tool, a robot or the like detects a case that a control shaft is collided with something in error to stop the servomotor at a high speed so as to minimize damages of the machine. When an estimated disturbance torque estimated by a disturbance torque observer 9 is over an allowance disturbance torque, an alarm signal is outputted. At this point, a plugging control unit 11 outputs a braking torque current command in a direction of stopping the servomotor until the servomotor 5 is stopped. An operation mode determination unit 12 receives an operation mode of the machine during the operation to set the allowance disturbance torque corresponding to the operation mode to the determination unit 10. According to the present invention, the detection of the collision of the machine 6 can be performed at higher speed and a braking distance after the detection so that damages of the machine during the motor rotates at a high speed can be minimized.

Abstract: A feedback control system modifies a drive signal to a plant which provides an achieved response signal in response to the drive signal. A first summing element provides a response error signal representing the difference between a desired response signal and the achieved response signal. An adaptive filter adjusts the response error signal in accordance with a dynamic behavior of the adaptive filter to provide a drive correction signal, the dynamic behavior being adjusted by a compensation device in response to the drive signal and the achieved response signal. A second summing element provides a corrected drive signal representing the sum of the drive signal and the drive correction signal. A storage device delays the corrected drive signal and a converter generates the drive signal during the next iteration as a function of the delayed corrected drive signal.

Abstract: Multiple motion controllers for controlling servo motors are connected by a digital communications link so that controlled axes of the motion controllers may be slaved together regardless of their physical proximity. A given controller broadcasts position or command signals on the communications link in response to a request report message from any another controller. A second request report message may stop the broadcasting to conserve link capacity. Time shifting implicit in the link messages is corrected by estimating the velocity of the master axis and extrapolating the position to the local axes' time of updating.

Abstract: A servomotor control method utilizing conventional linear control techniques, which permits easy introduction of sliding mode control. The phase surface of the sliding mode is made to be equivalent to a mode of obtaining a torque command by a conventional linear control, and a switching input (.tau.1) is added to the torque command (.tau.0) obtained by the linear control, thereby further obtaining a corrected torque command (.tau.). The switching input (.tau.1) is determined in accordance with the positive or negative sign of the torque command (.tau.0) and the signs of various values such as a position deviation (.epsilon.), a speed loop integral, etc., which are obtained during the calculation of the torque command (.tau.0).

Abstract: A control system having proportional and integral functions for controlling the rotational speed of a motor. The system includes a self-limiting integrator for avoiding or limiting integral wrapup, a problem commonly associated with integral control. The self-limiting integrator includes an integrator, limit comparator, OR gate, delay circuit, and sign reversal circuitry. The integrator reverses direction of integration when an error limit is realized. The error limit, a preestablished and adjustable value, can be used to determine the rise and settle time of the speed of the motor independently of the gain.

Abstract: In a magnetic bearing carrying a rotary shaft in the air, the rotary shaft is required to rotate substantially at the same position. In controlling the position of the rotary shaft, a first exciting current I.sub.f is supplied to a plurality of first electric magnets formed in the proximity of one end of the rotary shaft, whereas a second exciting current I.sub.r is supplied to a plurality of second electric magnets formed in the proximity of the other end of the rotary shaft. The first exciting current I.sub.f is represented by the sum of a first biasing current I.sub.f, a first control current i.sub.Hf for translation, and a first control current i.sub.Kf for rotary motion. The second exciting current I.sub.r is represented by the sum of a second biasing current I.sub.r, a second control current i.sub.Hr for translation, and a second control current i.sub.Kr for rotary motion. Under such conditions, a ratio I.sub.f /I.sub.r between the first and second biasing currents, a ratio i.sub.Hf /i.sub.

Abstract: An apparatus for stabilizing the speed of a motor has a phase comparator that identifies a phase difference between a reference signal and a speed signal. The apparatus acquires the speed of the motor and generates an output signal proportional to the identified phase difference. A controller receives the output signal. A control circuit for the motor is connected to the controller. The phase comparator comprises a sample-and-hold element, a sampling pulse shaper that is connected thereto and is input with the speed signal, a pulse shaper input with the reference signal, and a signal generator connected to the output of the pulse shaper and to the input of the sample-and-hold element.

Abstract: An adjustable time constant control system for a servomotor, determines the optimum adjustable time constant for a servomotor based on a moving amount, load, or the like, for every block of a machining program to reduce the machining time required by the adjustable time constant control system. A determination as to whether a velocity reaches a command velocity (Vt) is made based on the distance to a target moving position (step S1) . If the velocity reaches the command velocity (V.sub.t), the command velocity (V.sub.t), the command velocity (Vt) is used as a velocity (V) (step S2). On the other hand, if the velocity does not reach the command velocity (V.sub.t), a reaching velocity (Vu) is calculated (step S3), and the calculated value is used as a velocity (V) (step S4). Further, the maximum torque (Tmax) corresponding to the velocity (V) is determined from the torque curve (step S5), and an accelerating torque (Ta) is calculated based on the maximum torque (Tmax) (step S6).

Abstract: An improved electromechanical actuator controller or system, counteracting the control stability degradation caused by motor interaction with the load dynamics (actuator compliance), having decreased sensor noise sensitivity responses and minimal compensation implementation requirements. The controller includes a motor rate sensor and an actuator position sensor, whose signal outputs are combined in a complimentary filter to blend the dissimilar sensor signals to achieve the desired control signal. The complementary filter time constant is chosen to result in a stabilizing quadratic phase lead which allows the controller bandwidth to be increased to provide the desired faster electromechanical actuator controller time responses.

Abstract: A sliding mode control method is provided capable of improving the following ability of a control system with respect to a command at the time of change in the operating condition of a machine, and preventing vibration which tends to occur by the action of a spring element of the machine at the time of change in the operating condition. The processor of a servo circuit derives position deviation (.epsilon.) and speed deviation (.epsilon.) based on a command position (.theta.r) and an actual position (.theta.), estimates an torsion amount (.epsilon.n) and torsion speed (.epsilon.n) by effecting observer processing (Steps 100 to 101), and derives a switching variable (s) (102).

Abstract: A feedback control system provides an adjusted command signal to a plant in response to a command signal having a plurality of command signal components. The plant controls a subsystem and provides a feedback signal representative of the subsystem's achieved response to the adjusted command signal. An adaptive filter adjusts the amplitude and phase of relatively high frequency command signal components in accordance with a dynamic behavior of the adaptive filter. A compensation device adjusts a dynamic behavior of the adaptive filter in response to the feedback signal and the adjusted command signal. In one form of the invention, a low-pass filter passes command signal components of relatively low frequency, and a summing element generates the adjusted command signal in response to the output from the adaptive filter and the command signal components passed by the low-pass filter.