Abstract: A position control method for accurate position control of a driving source is disclosed. The method of the present invention comprises the steps of comparing a remaining driving amount of the driving source to a target position with a mechanical dead zone of a power transmission mechanism, controlling the position of the driving source by a proportional and derivative operation on a deviation of the position detected by the position detection circuit from a command position obtained from a speed command value while the remaining driving amount is larger than the mechanical dead zone, and controlling the position of the driving source by a proportional, integral, and derivative operation on the deviation of the position detected by the position detection circuit from the command position obtained from the speed command value when the remaining driving amount becomes smaller than the mechanical dead zone.

Abstract: The excitation of an oscillation in a mechanical system, such as a machine element, subjected to a jerk can be suppressed or at least attenuated by rounding a corresponding jerk curve and/or by tuning the stop band of a bandstop filter to the characteristic frequencies of the mechanical system or machine element. In combination, both measures can improve the positioning accuracy while at the same time minimizing excitation of oscillations.

Abstract: Apparatus, method and program for controlling electric motors to drive movable objects, wherein an input-rectifying device is operable, when a control signal to be applied to one of the electric motors requires the motor to be operated so as to operate the object in a direction opposite to a predetermined direction, to rectify the control signal so as to limit a motion of the object in the opposite direction, and a differential-control-quantity compensating device is operable after expiration of a predetermined time after a differential control quantity used together with proportional and integral control quantities to generate a control signal to be applied to another motor is updated on the basis of an error between a detected speed and a target speed of the object, so as to reduce the differential control quantity.

Abstract: A non-linear, semi-parametric neural network-based adaptive filter is utilized to determine the dynamic speed of a rotating rotor within an induction motor, without the explicit use of a speed sensor, such as a tachometer, is disclosed. The neural network-based filter is developed using actual motor current measurements, voltage measurements, and nameplate information. The neural network-based adaptive filter is trained using an estimated speed calculator derived from the actual current and voltage measurements. The neural network-based adaptive filter uses voltage and current measurements to determine the instantaneous speed of a rotating rotor. The neural network-based adaptive filter also includes an on-line adaptation scheme that permits the filter to be readily adapted for new operating conditions during operations.

Abstract: Based on a control object, a result of the detection of driving of an actuator and a response from a standard mathematical model of the actuator, the actuator is controlled, or in a servo system that controls the angle of a joint, etc., the control value is corrected so that the response from the thing to be driven and the response from the model of the thing to be driven are set to coincide with each other, and also based on a result of the correction of the control value, at least the moment of inertia of the thing to be driven is detected. Thereby, the moment of inertia of the driver and the like can be detected in real-time without providing a special sensor.

Abstract: A position controller for motors for increasing the position loop gain of a full-close control system without causing recurrence of vibration. The controller where a position signal representing the position of a movable table and outputted from straight-line motion position sensing means attached to a straight-line motion mechanism is used as a position feedback signal comprises differentiating means (2) for differentiating a straight-line motion position signal and outputting a straight-line motion speed signal, subtracting means (4) for calculating the difference between a speed command signal and the straight-line motion speed signal, integrating means (3) for integrating a difference signal outputted form the subtracting means, proportional gain means (1) for receiving the output signal from the integrating means, and adding means (19) for adding the output signal form the proportional gain means to the speed command signal and outputting a new speed command Vr.

Abstract: A controller for a machine such as a robot and a machine tool having an electric motor as a driving source of the machine, capable of suppressing a natural vibration of the machine and/or an attachment attached to the machine. A frequency or a cycle of the natural vibration of an end effector of the robot as the attachment or the machine itself is determined and a coefficient of a filter for suppressing an amplitude of the natural vibration is altered in accordance with the measured frequency or cycle of the natural vibration. In the case of suppressing a natural vibration of the end effector attached to the robot, frequencies or cycles of natural vibrations of various end effectors in accordance with an operation status of the end effector are determined and stored, and the coefficient of the filter is set in accordance with the stored frequency or cycle of the natural vibration in accordance with the end effector attached to the robot and the operation status.

Abstract: An equipment for controlling an industrial robot, which robot has a plurality of rotation and/or translation axles (ax 1-6), comprising a motor (15) at each of said axles for generating desired movements of the arms and/or the wrist, of which the robot is constituted, a sensor at each of the axles for measuring axle angle and/or axle position, a servo (9) for each of the axles for controlling the motors based on measurement values from the sensors, and a path generator (8) for generating at least one reference (&phgr;ref, &phgr;ref, &tgr;ffw) for each of the servos (9).

Abstract: A system for controlling the position of a rotating member suspended using a magnetic field includes at least one sensor that is operable to detect the position of the rotating member, the sensor further being operable to generate a position reference signal in response to the detected position. The system also includes a controller in communication with the at least one sensor and being operable to generate an actuator control signal in response to receiving the position reference signal. The controller is operable to introduce a phase lead in the actuator control signal in response to a rotational speed of the rotating member. The system further includes at least one actuator in communication with the controller that is operable to adjust the position of the rotating member in response to the actuator control signal by modifying characteristics of the magnetic field.

Abstract: In a procedure for the digital evaluation of the analogue output signals from a resolver with at least two stator windings, arranged perpendicular to each other on a stator, and at least one rotor winding on a rotor able to rotate in relation to the stator, a sinusoidal signal is applied to the rotor winding and sine, respectively cosine shaped signals, depending on the angular position of the stator in relation to the rotor, are extracted from the stator windings. These signals are further processed after conversion into digital signals by application of the inverse tangential function, in order to compute an angular value for the relative angular position between the rotor and the stator. This angular value is affected by a propagation delay time error, which is compensated for by the introduction of a control loop.

Abstract: A motor speed controller with high speed response characteristics.

Abstract: A human de-amplifier system for interfacing a human operator and a physical object through a physical plant, wherein the physical object has dimensions in the range of 1 micrometer to 1 mm. The human de-amplifier system uses an inner-feedback loop to increases the equivalent damping of the operating system to stabilize the system when it contacts with the environment and reduces the impact of the environment variation by utilizing a high feedback gain, determined by a root locus sketch. Because the stability of the human de-amplifier system of the present invention is greatly enhanced over that of the prior art, the de-amplifier system is able to manipulate the physical object has dimensions in the range of 1 micrometer to 1 mm with high stability and accuracy. The system also has a monitoring device to monitor the motion of the physical object under manipulation.

Abstract: An electronically assisted power steering system (10) for providing assist in response to a steering control signal includes a steering torque sensor (30) operatively connected to a vehicle hand wheel (12) for providing a torque signal indicative of applied steering torque. An electric motor control module (50) is connected to the torque sensor (30) and to an electric motor (32). The electric motor control module (50) includes an outer loop controller for generating a desired torque signal responsive to the applied steering torque. The outer loop controller includes a phase lag network in series with a second order network for compensating the desired torque signal. The electric motor control module (50) also includes an inner loop controller for generating a motor drive signal responsive to the desired torque signal output from the outer loop controller. The inner loop applies a motor drive signal to the electric motor to generate the required assistive torque.

Abstract: An automatic phase adjuster for the driver of a brushless motor is provided. This automatic phase adjuster can output a driving signal adaptively with a suitable phase-lead or phase-lag angle so as to allow the motor to be operated with the optimal output characteristics, including optimal output torque, optimal output efficiency, and optimal output power at all speeds. The automatic phase adjuster is configured variously in accordance with the particular type of the motor on which the automatic phase adjuster is used. For single-direction motors operated at a fixed speed, the automatic phase adjuster includes a phase-lead filter coupled to a Hall sensor which detects the motor speed. For single-direction motors operated at various speeds, the automatic phase adjuster includes a phase-lead filter, a phase-lag filter, a multiplexer, and a Hall sensor. The multiplexer selects either the phase-lead filter or the phase-lag filter to process the motor speed signal.

Abstract: In a linear feedback servo control system, the motion profile for each axis is pre-filtered before it is introduced to the servo loop for that axis. The motion profile is pre-filtered by a filter having an inverse amplitude response to the amplitude response of the servo loop. Therefore, the composite amplitude response of the filter/servo loop combination is approximately ideal for all relevant frequencies. The pre-filtering is done using constant delay filters, whether high pass, low pass or hybrid, that exhibit a phase lag corresponding to a time delay that is essentially constant at all relevant frequencies. Each axis of synchronized motion is pre-filtered with constant delay filters having the same time delay constant, but selected so that the motion of each axis provides sufficient accuracy within the intended bandwidth of that particular axis. Consequently, while phase lag is not zero, there is essentially constant delay for all axes at all relevant frequencies.

Abstract: In a device having a first member and a second member which are driven relative to one another by an actuator, a servocontrol derives feedback by sensing the torque applied on one of the members by the actuator. The actuator drive signal is modified by a compensation network in response to the torque measurement to provide stability across a bandwidth extending beyond the resonant frequency of the members, thereby providing smooth, accurate and precise motion.

Abstract: A servomotor control device including a drive pulse generating circuit for generating a pulse signal having a frequency corresponding to an actual frequency of a servomotor, and arithmetic operation unit for outputting a control signal on the basis of the pulse signal for control of the servomotor. The arithmetic operation unit generates the control signal by implementing an extrapolation correction on the basis of preestimated variation of a frequency of the servomotor due to a time delay between a moment when the pulse signal is generated and a moment when the control signal is applied to the servomotor.

Abstract: A gain and phase compensation circuit for use in the servo control system for an optical disk device comprises a digital signal input terminal for receiving an input digital signal to be treated, a first digital filter circuit having an input connected to the digital signal input terminal for compensating a gain of a low frequency band for the input digital signal, a second digital filter circuit having an input connected to the digital signal input terminal for compensating a phase of a high frequency band for the input digital signal, and an output circuit having a first input connected to an output of the first digital filter circuit and a second input connected to an output of the second digital filter circuit for combining the output of the first digital filter circuit with the output of the second digital filter circuit so as to generate a digital servo control signal.

Abstract: A two degree of freedom PID controller which includes a setpoint filter for performing a derivative operation on a process disturbance signal in accordance with a setpoint value and a control value of a controlled system, thereby outputting a setpoint signal, a PI-control operation device for determining a deviation between the setpoint signal and the control value, and performing a PI-control operation on the deviation, thereby outputting a manipulative signal, and an adder for adding the process disturbance signal to the manipulative signal output by the PI-control operation device, thus obtaining a sum signal, and for supplying the sum signal to the controlled system.

Abstract: A stability compensating circuit of a servomechanism wherein the output displacement of an actuator is controlled, comprising: a unit generating a reference input signal corresponding to a target value; a first adder which is provided in a first line between the reference input signal generating unit and the actuator and to which a feedback signal from the actuator is inputted through a second line between the first adder and the actuator; a second adder provided in the first line between the first adder and the actuator; a first compensating circuit provided in the first line between the first and second adders; and a second compensating circuit provided in a third line between the second adder and the actuator, the feedback signal from the actuator being inputted to the second adder through the second compensating circuit.

Abstract: A feedback system control device includes an adder producing a control signal from a feed forward signal and a correction signal. A system which processes the control signal drives the feedback system, which produces an output signal. A feed forward circuit, e.g., a four-pole network, receives the input signal and produces the feed forward signal. An error amplifier in the corrector processes the difference between the input signal and the output signal to produce an error signal. A corrector produces the correction signal from an input signal and this error signal. Two processors in the corrector each receive the error signal and produce respective modification signals between which there is a relative phase shift. An adder sums the modification signals to produce the correction signal.

Abstract: A control system having an open loop transfer function G expressed by a transfer function G.sub.2 of one control component having at least one integration element and a mass transfer function G.sub.1 of other control components and a saturation level of the other components expressed by the transfer function G.sub.2 set lower than that of the component expressed by G.sub.1.

Abstract: A control device for controlling displacement of a magnetically supported moving member according to a command. A feedback circuit detects the displacement of the moving member to servo-control the same to thereby ensure stability and robustness of magnetic supporting. A feedforward circuit has an input terminal receptive of a command and an output terminal connected to the feedback circuit, and cooperates with the feedback circuit while not disturbing the stability and robustness of the magnetic suppporting for controlling the displacement of the moving member according to the command.

Abstract: A power system stabilizer (PSS) to bring the constant in a phase lead-lag circuit of the PSS to an optimum value by having such procedures carried out in its phase lead-lag compensation circuit as to apply the ruler to lead the phase of the PSS when the period of the power fluctuation in each mode tends to decrease and to lag the phase of the PSS when conversely the period tends to increase by means of a fuzzy inference device to detect results of the periods weighted by the degrees of the tendency, to superpose the outputs obtained by application of the rule to obtain the center of gravity, and therewith finally to vary the constant in the amplification and phase lead-lag circuit of the PSS.

Abstract: A notch filter, used in a servo loop, for dampening a mechanical resonance of a mechanism to be servo-controlled, including a serial T-type filter with a capacitor-resistor (CR) network having a serial connection of a first, second and third capacitors connected between an input terminal of the serial T-type filter and an output terminal of the Cr network; a first resistor connected between a return terminal of the CR network and an interconnection of the first and second capacitors; a second resistor connected between the return terminal and an interconnection of the second and third capacitors; and a third resistor connected in parallel to the three serial capacitors. A notch frequency of the notch filter is adjusted by varying the resistance values of the first and second resistors. The first and second resistors may include fixed and/or potentiometer-type variable resistors. An output from the CR network may be divided to be fed back to the return terminal to provide feedback.

Abstract: A versatile time difference comparison compensation method of a control system, wherein a desired value or a reference value of feedback control is branched into several parts. One of the branches is directly compared with a feedback variable to obtain a first difference value and lag elements having various delay times are connected to the other of the branches, respectively, in order to make time difference comparison between the desired value or the reference value and the feedback variable to obtain second and third difference quantities, respectively. Various weighting elements receive the difference quantities inclusive of the first difference quantity to put various weights to the difference quantities and to obtain signals and the sum of the resulting signals is then calculated and the signal obtained by the sum is passed through a gain adjustment element to re-adjust a gain adaptive to a controlled system to produce an operation quantity.

Abstract: The positioning control apparatus includes a feedback compensatory compensatory system for performing high-accurate positioning and a feedforward compensatory system for carrying out high-speed output response. The feedforward compensatory system is provided with a dynamic characteristic of an object to be controlled and a dynamic characteristic reverse to that of a control system by a feedback compensation. Transfer characteristic from a position command to an output of the object is assumed to be 1. As a result, there can be easily obtained a desired output response as well as a desired control input.

Abstract: A stability compensating circuit of a servomechanism wherein the output displacement of an actuator is controlled, comprising: a signal source generating a reference input signal corresponding to a target value; a first summing amplifier to which the reference input signal and a signal corresponding to the actual output displacement of the actuator are inputted; a primary amplifier to which an output of the first summing amplifier is inputted and which amplifies the output of the first summing amplifier; a secondary amplifier to which an output of the primary amplifier is inputted and which further amplifies the output; a second summing amplifier to which an output of the amplifier is inputted.

Abstract: This invention is a method and apparatus for automatically adjusting the command signal of a servomechanism, to improve the accuracy of control over the motion of an object. In one embodiment, the command signal is advanced in time, to compensate for the delayed response of the servo. The time advance is repeatedly and automatically adjusted so as to minimize the magnitude of the tracking error. Each adjustment of the time advance is based on the value of a sampled error signal, taken at selected points in time. Other parameters of the command signal, such as the amplitude and average level, can also be adjusted, and the adjustments for all parameters can be done simultaneously. For a given parameter, the error signal is sampled at those points at which misadjustment of that parameter is most likely to contribute to the error of the system. Thus, in general, different parameters of the command signal are adjusted based on different sets of sampled points of the signal.

Abstract: A servo-control circuit that suppresses an incomplete integration term, which is contained in an integration gain of a velocity feedback loop in a velocity control block (5), when an error between a position signal from a mechanical system and a move command exceeds a predetermined reference value. As a result, a torque command applied to a current control block (6) is controlled so as to minimize a torque which causes overshoot along a static friction characteristic of the mechanical system. Thus, an effect equivalent to that achieved in an analog servo system by non-linearly manipulating a coefficient at the charge and discharge time of a CR time-constant circuit can be realized in a computerized digital servo-control system.

Abstract: A control mechanism employing an internal model coordination method according to the present invention is arranged to obtain a manipulation variable by comparing a desired value or a reference value with a feedback variable into which a controlled variable is transformed to provide an error, sequentially transmitting the error to an internal model which is composed of the same number of elements as its order, adding the outputs of a plurality of gain controllers into which the state variables of the respective elements are input, and comparing the result of the addition with another feedback variable supplied from a conventional regulator. The control mechanism is characterized by a new regulator arranged to receive as its input a branched signal of the desired value or the reference value and a path arranged to cause a signal obtained by addition of the output of the new regulator to the final state variable of the internal model to be input to a corresponding one of the gain controllers.

Abstract: A servo system having an improved loop stability and response time. A phase shifting circuit is inserted in the feedback loop providing an open loop phase lag characteristic at a resonance frequency of a load system in a range of -270.degree. to -360.degree.. The transfer function of the phase shifting circuit is preferably of the form: ##EQU1## where .tau..sub.3 and .tau..sub.4 represent time constants of the circuit.

Abstract: Position of an object is detected by a position detector (10) and position data detected by this position detector is stored in a memory circuit (11). A time data supply section (21) supplies time data (.DELTA.t) as a lead compensation parameter. A compensation circuit (22) reads out position data (Dx (-.DELTA.T)) for a preceding time corresponding to the supplied time data (.DELTA.t) from the memory circuit (11) and corrects at least one of present position data (Dx) and target position data (Sx) in accordance with the difference between the read out position data and the present position data detected by the position detector thereby performing lead compensation. A control signal relating to the position of the object is generated in accordance with the present position data corrected by the compensation cirucit and the target position data and the positioning control is made by this control signal.

Abstract: A digitizing method for obtaining data indicative of the three-dimensional shape of an object by effecting movement along at least one axis (X or Y axis) under numerical control on the basis of path data and along another axis (Z) under tracer control and monitoring the present position along each axis. A numerial control unit performs numerical control to moving a tracer head in X and Y directions. A tracer control unit generates a Z-axis velocity command V.sub.z to move the tracer head along the Z axis. The numerical control unit counts pulses generated by a motor driving a tracer control axis to obtain the present position along the tracer control axis. The numerical control unit also obtains a commanded position along each numerical control axis (X,Y axes) by using the path data, and obtains a present position, represented by a machine position, by substracting an amount of servo-system delay (i.e., the contents of error registers) from the commanded position.

Abstract: The present invention is a device for compensation of electric transfer functions of electric or electronic sensors (G), detectors, instruments or four-poles. According to the invention, the signal from the unit (G) to be compensated is connected to a differential amplifier (D) with a feed-back network (Z) having a transfer function that is substantially the same as the transfer function to be compensated. The compensating device has a transfer function that approximately is inverse to the transfer function of said sensor (G). The signal that the sensor senses and that is distorted by the nonlinear transfer function of the sensor is then restored. The feed-back network can either be passive or consist of electrically controllable active filters.

Abstract: Described is a novel technique and associated arrangement for determining the noise-free value of a system parameter (e.g., head position in a disk drive) which is time variable and (usually) has a noise component as detected. The technique involves processing the (as detected) noise-including value and passing it, plus a "Time-derivative version" thereof, through "Second Order/Summing" filter means.For instance, the technique is described as particularly useful with the "track-following servo" (part of the transducer positioning means) in a high density disk file (where track density is higher than usual) to secure superior head-displacement error values which are more noise-free. Thus, (see FIG. 4), a pair of first values V.sub.a, V.sub.b are secured by detecting motor current sense voltage V.sub.i, integrating it with respect to time and passing the result through a pair of novel "second order filter" means--one band-pass (F.sub.1), the other low-pass (F.sub.2); while also securing a third value V.sub.

Abstract: A servo system 10 (FIG. 1) for positioning a sighting mirror 11 connected to a pulley 16 comprises a drive motor 13 rigidly connected to a drive pulley 15 in turn coupled by a tensioned drive belt to the pulley 16. Angular position of the motor or pulley 15 is measured by sensor 18 and passed by way of phase advance network 19 and amplifier 21 to produce an error signal for the drive motor. The pulley 16 is outside of the servo loop and any oscillations induced in the tensioned belt at its resonant frequency, possibly originating from electrical noise in the servo loop, will be uncontrollable.

Abstract: An electrohydraulic servo control system responsive to a load acceleration or velocity command input signal wherein the input command signal is integrated and compared with position feedback from the valve actuator and load to obtain an error signal which controls the actuator. The velocity command input may be multiplied by an exponential factor to compensate for system following error. Another modification contemplates resetting of command signals to compensate for following error and to eliminate dead time upon change of direction of the load by the operator.

Abstract: The invention relates to a device for increasing the tracking accuracy of an aiming system for a gun or the like which includes a gun servo. The gun servo comprises a special stabilizing and accuracy-increasing network (20) which comprises one or a plurality of integrating second-degree filters (25) the transmission functions (G.sub.R) of which have such a form that the amplitude as a function of the frequency has a maximum near the expected frequency of the base movements of the gun and/or the movement of the target, which makes it possible to have a high system gain around and below said frequency.

Abstract: A numerical control system for a lathe having a cutting tool attached to at least one movable slide. The control system includes velocity or acceleration command generators causing the slide to accelerate to a predetermined velocity prior to the initiation of thread cutting. A digital or analog compensation network causes the slide to follow its associated command signal with zero following error.

Abstract: In a process in which a feedstock is provided through a desalting unit prior to introduction into a fractional distillation column, the feed stream flowing to the desalting unit is split and passed through multiple heat exchangers. Method and apparatus is provided for maintaining a desired effluent flow rate out of the desalting unit and for maintaining the temperatures of the split feed streams substantially equal. After passing through the desalting unit the feed stream may again be split and passed through multiple heat exchangers prior to introduction of the feed stream into the fractional distillation column. Method and apparatus is also provided for maintaining the temperature of the split feed streams provided from the desalting unit substantially equal.

Abstract: A process control system is provided in which a process variable is compared to a set point for the process variable by a process controller with the results of the comparison being utilized to control the process in such a manner that the process variable will be substantially equal to the set point for the process variable. A critically damped response of the process variable to a change in the set point is achieved by utilizing a process controller which has the characteristics of a proportional-integral-derivative controller followed by a first order lag. Tuning of the process controller is accomplished by changing a time constant which is common to the proportional, integral and derivative terms of the proportional-integral-derivative controller and also common to the first order lag.

Abstract: An improved continuous-path-positioning servo-control system is provided for reducing the effects of friction arising at very low cutting speeds in the drive trains of numerically controlled cutting machines, and the like. The improvement comprises a feed forward network for altering the gain of the servo-control loop at low positioning velocities to prevent stick-slip movement of the cutting tool holder being positioned by the control system. The feed forward network shunts conventional lag-compensators in the control loop, or loops, so that the error signal used for positioning varies linearly when the value is small, but being limited for larger values. Thus, at higher positioning speeds there is little effect of the added component upon the control being achieved.

Abstract: A servo control system for the positioning of a projector comprising a dit current motor having the projector connected to the shaft of the motor, and a digital computer for providing command signals to move the projector to a programmed position at a programmed velocity within a predetermined time period. A potentiometer produced an electrical signal indicative of the actual position of the projector, and a tachometer produces an electrical signal indicative of the actual velocity of the projector. Feedback means, in turn, provides a position error signal indicative of the difference between the programmed position and the actual position of the projector, provides a velocity error signal indicative of the difference between the programmed velocity and the actual velocity of the projector, and varies, in response to the position and velocity error signals, the voltage level of the command signal such that the projector will attain the programmed position within the predetermined time period.

Abstract: There is provided a motor control system adapted for use, for example, with a sample analyzer, having means for generating signals representative of motor movement, and a logic circuit for analyzing the motor movement signals to determine increments of movement and the direction of movement. Digital circuitry is also provided for tracking the actual motor position as it is moved in either a forward or reverse direction, and comparing the tracked position with a programmed destination position. When and only when the motor is within a predetermined range of the destination position is a variable control generated, causing braking of the motor so that it stops exactly at the programmed destination position.

Abstract: An apparatus for controlling the running track of a trackless moving body comprising a guide wire, a position deviation sensor unit mounted on the trackless moving body for sensing a deviation of the position of the moving body relative to the guide wire, a steering control circuit connected to the position deviation sensor unit, and a steering drive unit connected to the steering control circuit for steering the moving body. The steering control circuit comprises a first-order lag circuit receiving the output signal from the position deviation sensor unit, a subtractor receiving the output signal from the position deviation sensor unit and the output signal from the first-order lag circuit, and a comparator receiving the output signal from the subtractor.

Abstract: A control unit for automatically controlling the angular position of a reversible, motorized device, such as an antenna rotor, in response to a signal from an external sensor, such as a potentiometer coupled to the rotating shaft of a windvane. The unit includes integrated circuits and other electronic components for monitoring the windvane signal and for activating the rotor, as necessary, to maintain its alignment with the sensed wind direction. The unit also comprises means for providing: a no-response zone of adjustable width about the momentary, average wind direction; an adjustable, time delayed response to changes in wind direction; an automatic reversal of rotation if the rotor approaches the .+-.180.degree. position while searching for the wind direction; an automatic disabling of the rotor for windspeeds less than a selectable, threshold value.

Abstract: Apparatus for damping operator induced oscillations of a controlled system responding to an operator controlled signal (DEP) utilizing a lag-lead filter (14) for frequency and amplitude estimation of the control input, and a rectification and smoothing filter (16) for producing a signal proportional to the absolute value of the frequency and amplitude estimate for use in suppression of the control system output signal (DEC). In one embodiment, this is accomplished by computing a correction signal in a correction generating section (18). In a second embodiment, a second rectification and smoothing filter (21) produces a signal proportional to the absolute value of the controlled input signal. A ratio of the outputs of the first and second rectification and smoothing filters is then used in a generator (24) to generate a gain factor k.sub.

Abstract: In a motor control circuit, a rotational speed detection signal containing a ripple component superimposed on a d.c. component is applied to both a low pass filter/phase lagging circuit and to a phase leading circuit, the output signals of which have a phase difference of approximately 180 degrees, to effectively cancel the ripple component and thereby extract only the d.c. component. The latter is balanced against an r.p.m. reference voltage in a comparison circuit whose output is fed back to a drive winding control circuit of the motor.

Abstract: This invention relates to devices for damping oscillations in electromechanical and automatic control systems comprising actuators, various drives and flexible members providing mechanical coupling between the actuators and drive motors.In the general case the hereinproposed device furnishes a corrective signal being in phase opposition with respect to the a-c component of the signal taken from a moment or force transducer. This signal is applied to the input of the controlled drive, thereby damping mechanical oscillations. The device, according to the invention, may comprise several channels, each channel having such series-connected components as a fundamental-frequency sine-wave signal generation unit, a differentiating unit, a net time lag tuning unit, and an amplitude tuning unit.