Abstract: A servo positioning circuit having a speed detection circuit for detecting a real speed from a position signal from a servo object; a speed error detection circuit for generating an error between a target speed and the real speed; a position error detection circuit for generating a position error signal from the position signal; a switching unit for switching connection of the servo object to the speed error detection circuit or the position error detection circuit; and a main processing unit for generating a target speed in accordance with the position signal and controlling the switching of the switching unit. When the servo object nears a target position, speed control by the speed error detection circuit switches to position control by the position error detection circuit.

Abstract: A technique for overcoming the difficulties that arise from the transition between coarse and fine loop control. Coarse and fine phase locked loops, each having a respective latch provide a coarse number in the range 000.0.degree.-359.9.degree. and a fine number in the range of 0.0000.degree.-0.9999.degree.. The coarse number is offset relative to the fine number so that the least significant digit (tenths digit) of the coarse number is always less than the most significant digit (tenths digit) of the fine number over the entire range of motion. The fine number latch is clocked by a reference clock (ZDS) while correlation circuitry provides a clock signal for the coarse number latch. The correlation circuitry generates the clock signal when the tenths digit of the coarse number agrees with the latched fine number. The result is a latched fine number and a coarse number that is latched when it correlates with the fine number (tenths digits agree).

Abstract: The invention relates to a reference-point return method for returning a movable element of a machine to a reference point using solely a linear scale, without relying upon a limit switch. The method includes providing the linear scale (1) with a second scale portion (2) for stipulating a deceleration starting position and a reference-point position, in addition to first scale portion (3, 4) for generating two-phase signals for position detection, generating signals (S.sub.1, S.sub.2) indicative of the deceleration starting position (D) and reference-point position (O) from the second scale portion (2) of the linear scale, slowing a reference point return rapid-traverse velocity (Va) to a reference-point return rapid-traverse velocity (Vb) using the deceleration starting signal (S.sub.1), and effecting return to the reference point by stopping movement in response to the reference-point signal (S.sub.2).

Abstract: A system for carrying out reference point return in a numerical control device is provided, including a deceleration dog having a short length and arranged at a machine table, a deceleration limit switch operated by the deceleration dog, for generating a deceleration start signal, and a time setting device (6) for setting a deceleration time, starting with a generation of the deceleration start signal and ending with a generation of a deceleration end signal, and a slow-speed travel time. A reference point return processing device (5) starts a deceleration of the machine table in response to the deceleration start signal, and stops the machine table at a first electrical grid point reached by the machine table after the slow-speed travel time has elapsed after the passing of the deceleration time.

Abstract: A spindle motor controlling apparatus having a motor driving device, a motor speed controlling device, a MICOM and an image processing device uses a horizontal synchronization comparing device which detects a horizontal synchronization signal of the image processing device and compares the detected synchronization signal with a reference synchronization signal and applies the compared signal to the MICOM. The motor driving device further includes a switching part for providing power according to the control signal of the MICOM to the spindle motor.

Abstract: In a position control system having force as a manipulated variable and position as a controlled variable, negative feedback of position and velocity is performed. Positive feedback of acceleration is performed through a first order lag circuit. Alternatively positive feedback of velocity is performed through a quasidifferential circuit. By the combination of negative and positive feedback, it is possible to stabilize vibration characteristics of the mechanism, which tends to make the control system stable, and to achieve position control with high gain, high response and high accuracy.

Abstract: A load state decision apparatus of a servomotor where a load current value of a servomotor during operation is sampled and compared with a prescribed value and then the load state is decided based on the result, a motor current value is detected by adding the function to the existing apparatus and the detected motor current value is sampled at prescribed time intervals and stored in a memory, and an effective current value is calculated from the current value data and the calculated effective current value is compared with the rated current value and the load state of the servomotor is decided, thereby a converting or detecting apparatus need not be installed externally but the load state can be decided automatically.

Abstract: An actuator driving circuit for a servocontrol system comprises an amplifier for amplifying an error signal obtained in the servocontrol system to produce a driving signal supplied to the actuator, a power supply voltage source for producing a first power supply voltage and a second power supply voltage higher the first power supply voltage, a power supply voltage selector for selecting one of the first and second power supply voltages so as to supply the amplifier with the selected one of the voltages, and a level detector for detecting a specific portion of the error signal having such a level as to cause the amplifier to produce a portion of the driving signal having a level limited to be constant under a condition in which the first power supply voltage is supplied to the amplifier and for producing a detection output by which the power supply voltage selector is controlled to select the second power supply voltage in place of the first power supply voltage when the specific portion of the error signal is

Abstract: A rotary element (10) such as a robot arm is to be positioned by an actuating drive to a position determined by a desired value signal. An angle pick-off (20) provides an actual value signal. A first controller (36) provides a first controller output signal through an adaptive transfer element with limitation. The first controller output signal is applied to a first torque motor (18) the rotor of which is directly connected with the rotary element (10). A second controller (38) provides a second controller output signal, which is applied to a second torque motor (22). The second torque motor (22) is connected with the rotary element (10) through a step down system (26) and a resilient coupling member (30). A coupling path (40) with an integrator applies a trimming signal dependent on the input of the first torque motor (18) to the input of the second torque motor (22).

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

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

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

Abstract: A technique for overcoming the difficulties that arise from the transition between coarse and fine loop control. Coarse and fine phase locked loops, each having a respective latch, provide a coarse number in the range 000.0.degree.-359.9.degree. and a fine number in the range of 0.0000.degree.-0.9999.degree.. The coarse number is offset relative to the fine number so that the least significant digit (tenths digit) of the coarse number is always less than the most significant digit (tenths digit) of the fine number over the entire range of motion. The fine number latch is clocked by a reference clock (ZDS) while correlation circuitry provides a clock signal for the coarse number latch. The correlation circuitry generates the clock signal when the tenths digit of the coarse number agrees with the latched fine number. The result is a latched fine number and a coarse number that is latched when it correlates with the fine number (tenths digits agree).

Abstract: The present servosystem positions a movable member such as an optical head over a rotating disk with a constant velocity and high positional accuracy by utilizing a fast analog feedback loop that is controlled by a slower digital loop. The analog feedback loop locks the speed of the movable member to the speed of the rotating disk in a spiral recording track. The progress of the movable member is constantly monitored with the digital loop. A velocity error of known magnitude and direction is introduced into the system. When the error exceeds a preset limit an error of the known magnitude but of the opposite direction is introduced. The servosystem thus zig-zags about the desired position with small velocity changes to provide a substantially constant velocity system with high positional accuracy.

Abstract: A digital current control arrangement for optimizing the transport time delay of a thyristor power supply used as a source of armature current for a DC motor utilizes a coarse gate angle interrupt subroutine to perform a preliminary calculation of the gate firing angle for the next thyristor to be fired. The coarse gate angle calculation is performed at a predetermined time following the firing of a previous thyristor. A finite gate angle interrupt subroutine is also provided for recalculating the gate firing angle at a second predetermined time just prior to the firing of the thyristor. The finite and coarse gate angle interrupt subroutines both perform their respective calculations using the common parameters. A flag passing arrangement is also included in the current control arrangement and is effective to insure that the finite gate firing angle is the preferred calculation used in the firing of the next thyristor.

Abstract: In an X-Y addressable workpiece positioner the workpiece to be positioned, such as a semiconductive wafer to be aligned with a mask image, is coupled to move with a work stage moveable in X and Y direction and having a two-dimensional array of positioning indicia affixed thereto for movement therewith. An enlarged image of a portion of the positioning array is projected onto a relatively stationary sensor stage to derive an output determinative of the X and Y coordinates of the positioning array relative to the position of the sensor. The sensed X and Y coordinates of the positioning array are compared with the X and Y coordinates of a reference positioning address to derive an error output. The work stage is moved in response to the error output for causing the workpiece to be positioned to the reference address.

Abstract: A method of and apparatus for controlling the velocity of an industrial robot where the velocity is controlled without producing an edge when an instruction velocity is higher than an allowable velocity and an operator can readily recognize the actual velocity of the robot. The method includes the setting of an allowable velocity for a first step section or each of step sections in an acceleration or deceleration section between taught points for each of the axes of the robot. At the first or each step section an instruction velocity to each axis is compared with a corresponding allowable velocity, and when the former is highter than the latter, a control cycle after which a next trigger signal is to be developed is modified using the allowable and instruction velocities.

Abstract: A threaded fastener assembly tool is affixed to the output shaft of a DC motor, the torque of which is controlled by the current through the windings. An angular position encoder is attached to the shaft. A microprocessor monitors the angular position of the shaft as a function of time and controls a programmable current source which provides current to the windings of the motor. The processor varies the amount of torque applied to the fastener tool as a function of various parameters to control the installation of the fastener and detect defective fastener units.

Abstract: A control apparatus for a linear motor for driving a pickup of an information storage/readout apparatus with which the pickup can be moved more quickly and accurately to a desired target position. A slider for supporting the pickup is provided which is movable in a straight line. A magnetic circuit for forming a magnetic gap extends in the moving direction of the slider. A moving coil is mounted on the slider having at least a portion located within the magnetic gap. The voltage induced across the moving coil is detected to product a signal indicative of the velocity of the pickup. A velocity feedback loop feeds back the detected voltage to a driving source of the coil. The value of the feedback coefficient of the velocity feedback loop is set in accordance with the operating mode of the apparatus.

Abstract: Disclosed is a position detecting method and apparatus which are suitable for detecting the position of a moving body on the basis of the output of a position detector for generating two-phase periodic waves having a phase difference of a quarter period, the method comprising the steps of: comparing either one of the two-phase periodic waves with a predetermined reference value having hysteresis to thereby obtain a roughly estimated position for every half period of the one periodic wave; analog-to-digital converting the two-phase periodic waves and a zero-cross value for every sampling period to thereby obtain a finely estimated position; and detecting the position of the moving body on the basis of the roughly estimated position and the finely estimated position while correcting an error due to the hysteresis at the starting point of the roughly estimated position, by use of the relationship between the roughly estimated position and the finely estimated position.

Abstract: In an industrial robot including a control apparatus capable of executing control of the robot in a position control mode, a velocity control mode and a current control mode. The control apparatus includes a changeover section (20) for executing changeover between the position control mode and the current control mode. The position of an object is sensed by driving a set of arms of the robot in a force control mode which is a combination of the velocity control mode and the current control mode, and detecting the position at which the arms contact an object and are halted. Detection of the halted condition is performed based on a condition of an output signal produced from a position sensor (13), and by repetitively performing such detection for a plurality of different points on the body surface, a plurality of position values are derived which are compared with reference position data.

Abstract: A system for positioning equipment quickly and accurately over a plurality of desired positions by employing a "long move" mode of operation and a "short move" mode of operation to adapt the operation of the positioning system to variable and changing conditions. The system generally includes a microprocessor as the controlling means, a controlled valving means, a pressure source coupled to the valving means, an encoder sensing means and a positioning means defined by a pneumatic cylinder.

Abstract: A hybrid sample rate servo motor employing rate feedback compensation is disclosed. The system employs a shaft encoder having a predetermined resolution to provide position data which are pulses indicating the shaft has moved another resolution unit. Under high motor velocity conditions the rate compensation feedback loop is operated at a conventional constant sample rate. Under low velocity conditions, the sample rate at which the rate compensation feedback loop is operated is modified so that rate samples are taken and calculated only when new position data are available from the motor encoder. Rate quantization error is substantially reduced, thereby leading to more robust controller operation.

Abstract: A microprocessor based electric actuator control system is provided which allows accurate determination of the forces opposing movement of manipulator driveshaft. The control system electronically sets a predetermined current through an actuator to produce an electromagnetic force. A displacement measuring device, in conjunction with a time clock measures velocity and calculates acceleration of the actuator in response to the current. The force on the shaft is computer varied such that the acceleration is determined. For the acceleration to be zero, the electromagnetic force be exactly balanced by forces equal but opposite in magnitude. Since the force value is determined by the computer, the opposing force is also accurately determined with no external sensing device needed.

Abstract: A digital servo control system in a data recording disk file has a single processor which generates the control signal to the actuator at two different rates, depending on whether the read/write head is being moved between data tracks or is following a specific track. A sampling clock generator receives servo timing information from a recorded servo disk surface and generates interrupt signals to the processor at predetermined frequencies selected by the time required for the processor to run the algorithm which generates the control signals. Upon receipt of a seek command to move the head of a target track, or a predetermined head position error signal indicative of arrival of the head to the target track, the microprocessor enables or disables appropriate interrupts so as to select one of the appropriate rates for generating the control signals. The digital servo control system thus allows servo position information to be sampled at a higher frequency during track following.

Abstract: A time base control system for a spindle servo motor in which the time base is both coarsely controlled and finely controlled. According to the invention, when the recording head is alternately tracking and jumping tracks, the controllable range of the fine tuning is widened and the course tuning is gradually increased.

Abstract: A machine positioning apparatus and method are disclosed in which motor control values are established by causing intentional overshoot of the destination, and automatically reducing the motor control values each time an overshoot occurs. The system disclosed is a three stage system in which: (1) the first stage is a continuation motion relatively fast stage wherein the motor control values relate to the distance traveled; (2) the second stage is a much slower stage in which a series of interim targets are set, each of which is at a distance from current position which is a fraction of the remaining distance to destination, the motor control values during the second stage being motor duty cycle values; and (3) the third (final) stage is the slowest and involves setting a series of interim targets to be passed, each of which is substantially the current position, the motor control values during the third stage being motor duty cycle values.

Abstract: Disclosed is a printer which drives a drive motor for a type wheel or a carriage therefor by a signal derived by processing a first digital signal resulting from a position error signal and a second digital signal which is delayed by a predetermined time period. The digital signals can be processed by an LSI chip which assures a highly reliable, low cost and compact printer.

Abstract: An electronic control and regulation device for a machine or like apparatus has a plurality of printed circuit boards in a housing, each of the printed circuit boards having interconnected analog and digital circuitry with respective analog and digital terminals. The analog and digital terminals of all of the boards are interconnected respectively by analog and digital conductor bundles, the analog conductor bundle running to the machine or apparatus to be controlled, and serving as well to supply the electric current to the analog part of each printed circuit board.

Abstract: In an electronic typewriter having a printing device of the daisywheel type, the direct current electric motors which control the rotation of the character-carrying element, the movement of the carriage along the various printing positions and the rotation of the platen roller for line spacing are associated with corresponding transducers which detect the angular position thereof, and are actuated by a single integrated circuit connected to a microprocessor by an address and data bus (43). The microprocessor determines, for each of the motors, the angular amplitude of the rotary movement and the time required to cover each of the elementary angular distances, in accordance with a given speed law and addresses with data, including the said time, a plurality of circuit modules (B1, B2, B3) individual to the motors. The modules issue motor command signals (e.g. M11, M21, M31).

Abstract: A method and apparatus are disclosed for positioning a transducing apparatus relative to a rotating storage medium through the use of an externally commutated positioning apparatus under control of a processing element. In addition, a control method is disclosed which includes an initial determination of salient parameters associated with the apparatus. Positioning of the transducing apparatus is achieved through a plurality of control modes which are responsive to the determined parameters. In addition, the accuracy with which position of the transducing apparatus is determined varies among the modes with the remaining distance yet to traverse to a desired destination position.

Abstract: A weft yarn feed device (1) comprises a measuring and storing drum (7) for storing a predetermined length of a weft yarn (4) thereon for picking operation, a rotary yarn guide (6) for winding the weft yarn (4) on the measuring and storing drum (7), a feed motor (8) for rotating the rotary yarn guide (6), a drive control unit (3) for controlling the operation of the feed motor (8), and a command control unit (2) which gives commands to the drive control unit (3). The length of the weft yarn (4) wound on the measuring and storing drum (7) is detected accurately on the basis of the relation between the number of rotation of the rotary yarn guide (6) and that of the crankshaft of the loom, and a detection signal indicating the length of the weft yarn (4) wound on the measuring and storing drum (7) is fed back to the command control unit (2) to control the feed motor ( 8) properly for winding a predetermined length of the weft yarn (4) on the measuring and storing drum.

Abstract: The invention comprises an automated system 10 for the accurate positioning of movable parts bins 16 in relation to a preferred fixed location 26. The automated system consists of a number of movable parts bins 16 arranged on a conveyor 14 which is driven by a drive mechanism 18. The drive mechanism 18 controllably moves the conveyor 14 and therefore the bins 16 to desired locations in association with a coarse position sensor 24 and a final approach sensor 26. Both the sensors and the conveyor drive mechanism are interconnected with an electronic controller 28. This electronic controller monitors the position sensors in order to control the drive mechanism in a manner which positions the preselected parts bin at the desired location.

Abstract: A control system for positioning a movable member, includes a first control portion operative to move the movable member at a relatively high moving speed toward a position which is in proximity to a target stop position, the first control portion also being operative to decrease the moving speed of the movable member to a creep speed when the movable member moves from a predetermined deceleration starting position to said position in proximity to said target stop position; a second control portion operative on the movable member, after the creep speed is established, to place the movable member at said target position with a relatively high positional accuracy; a detector for detecting a positional error of the movable member with respect to reference at a time when said creep speed is established; and a third control portion for changing the deceleration starting position on the basis of detection by the detector.

Abstract: A speed detecting device for an electric motor in which the angular stopping position of a rotary shaft is controlled with a high precision. A magnet is mounted on a rotary shaft of the motor, and a position detector detects the position of the magnet as rotated by the motor, thereby producing an output signal having a linear region. A speed calculator samples this signal in the liner region at predetermined time intervals and performs a division operation whereby a difference between a present sampled value and a preceding sampled value of the output signal is divided by the time interval, thereby to produce a speed signal which is applied to the motor as a control signal.

Abstract: A position control system for positioning a D.C. motor at a desired position operates in a speed detection mode in which the D.C. motor is driven to rotate at a predetermined high speed, and in a position detection mode wherein the position of the D.C. motor is precisely controlled. In the speed detection mode, the control circuit forms a phase-locked-loop (PLL) control circuit which compares the phases of the speed instructing pulse signal and the rectangular signal derived from the actual rotation of the D.C. motor. The motor speed is controlled in accordance with the phase difference between the speed instructing pulse signal and the rectangular signal derived from the actual rotation of the D.C. motor.

Abstract: A velocity of a motor which selects a type element of a type head or a motor which drives a carrier carrying the type head in a printer is controlled in accordance with a positional error which represent a distance from a present position to a target print position of the type head or the carrier. When the motor is stopped at a desired position, it is appropriately damped.

Abstract: A method of returning a movable machine element having a flat dog to a zero point includes advancing the movable machine element in the direction of the flat dog, stopping the movable machine element after a changeover signal (S.sub.D) produced by the flat dog is detected, reversing the direction of the movable machine element, moving the movable machine element a first predetermined distance (L) and stopping it after the changeover signal (S.sub.D) is received again, then moving the movable machine element in the opposite direction a second predetermined distance (l) shorter than the first predetermined distance (L) and stopping the movable machine element, thereafter moving the movable machine element at a low velocity and stopping it at an initial one-revolution signal of a servomotor, which operates the movable machine element, after the changeover signal produced by the flat dog is detected.

Abstract: An up-down counter is fed pulses generated manually and/or automatically from either or any of two or more command sources. Gating circuitry ahead of the up-down counter may be used to enable counts from only one source at a time. The output of the counter represents the magnitude of the parameter to be controlled. The purpose is to transfer control of a parameter to any of several command sources without changing the value of the parameter, thereby achieving "stepless" switching. Only one counter is needed regardless of the number of command sources, no synchronizing circuitry is required, and switching is provided with no steps or delays. Multiple command sources may be active simultaneously when command source input gating is not used ahead of the up-down parameter magnitude counter.

Abstract: An absolute position detecting system for a servocontrol system which has its operation controlled in accordance with a numerical control program. Resolvers 202 and absolute encoders 110 made rotatable with a servomotor 105, are set at a predetermined revolving ratio so that the absolute positions of operating axes may be detected highly accurately from the revolution outputs of the two. The detecting operations can be performed for the plural operating axes by using one detecting circuit commonly.

Abstract: A system for controlling drive of a movable member for carrying a workpiece such as a semiconductor wafer, the system including a first servo control system effective to move the workpiece carrying member at a relatively high speed and with a relatively low positional accuracy for stoppage of the workpiece carrying member, a second servo control system effective to move the workpiece carrying member at a relatively low speed and with a relatively high positional accuracy for the stoppage of the workpiece carrying member, and a system for selecting one of or a combination of the first and second servo control system in accordance with a positional accuracy required with respect to a target position of the workpiece carrying member.

Abstract: A position/speed detection method and apparatus employing an encoder mounted on the rotary shaft of a motor in order to control the position and speed, wherein the coarse position and fine position are simultaneously detected by an encoder pulse and an encoder original signal, respectively and the detected results are combined to detect the position and speed of the motor with high precision.

Abstract: A linear position indicating system utilizing a fixed chain (20) which engages a pinion (32) connected to a mechanical input of an encoder (26) for providing position information. Encoder (26), supported on a relatively movable cross slide (14), provides an output signal indicative of the position of crosslide (14) relative to member (12) from which it is supported. Idlers (34, 36) are provided to guide the chain (20) around pinion (32) to ensure a large contact of approximately 180.degree.. Proximity switches (50, 52) are disposed for detecting when crosslide (14) is near its travel limits. The distance between switches (50, 52) is adjustable so they can be set at a precise separation. A counter (72) is provided for counting pulses as crosslide (14) moves between switches (50, 52). The output of counter (72) is used along with the know separation between switches (50 52) for calibrating the output of encoder (26).

Abstract: A direct-current electric motor (29) used for, for example, positioning a printing device in an office machine, is controlled by an arrangement comprising a microprocessor (40) which causes the motor digitally to perform accelerations and/or decelerations to maintain it close to a desired speed programmed in relation to the distance to be completed. Control between the actual speed of the motor and the desired speed is effected utilizing the timing signals (FTA, STB) generated by a transducer (35) connected to the motor. During a first phase, the microprocessor compares the times taken to complete a series of angular steps of rotation, the steps following a schedule of decreasing size with stored reference times and effects accelerations and decelerations of durations proportional to any discrepancies.

Abstract: A system and method are disclosed for precisely positioning a movable member to a desired fine position after a selected coarse position is reached. In a preferred embodiment of the invention a processor-controlled typewheel servo control system is responsive to a command signal for a selected coarse position for selectively utilizing from a memory circuit preselected stored adjustment information for the selected coarse position comprised of an associated coarse position count and quadrant information related to the sinusoids generated by an optical encoder in order to make a precise fine position adjustment in the position of a typewheel after the selected coarse position is reached for that typewheel.

Abstract: A servomotor speed control system includes a ROM table which stores a minimum distance suited for each motor speed. When the minimum distance corresponding to the current motor speed becomes shorter than the current distance from the current motor position to a positioning target point, the instructed speed is reduced to decelerate the servomotor rotation. In a preferred form, the unit of the distance is identical with an interval of a position indicating signal developed from a rotary encoder associated with the servomotor.

Abstract: An adjustable servo-system for controlling the operating condition of its servo-motor adjustably includes an indicator unit capable of indicating a new optimum operating time to be used. The operator can set the new optimum operating time in the servo-system just by looking at the indicator.

Abstract: A D.C. motor position control system operates either in the motor speed detection mode or in the motor position detection mode. A rotary encoder develops an approximate sinusoidal position indicating analog signal in response to the rotation of the D.C. motor. A waveform shaping circuit receives the approximate sinusoidal position indicating analog signal and develops a rectangular position indicating digital signal to a phase comparator which compares the phase of the rectangular position indicating digital signal with the phase of a speed instructing pulse signal so as to control the motor speed in a phase-locked-loop (PLL) manner in the motor speed detection mode. A slice level determination circuit divides the voltage level of the approximate sinusoidal position indicating analog signal into 16 (sixteen) degrees to obtain a sliced position indicating digital signal which is used to control the motor position in the motor position detection mode.

Abstract: In a system for controlling a servo actuated controlled device, an input signifying the position of displacement of an aircraft stick or similar manipulatable unit is processed to provide a variable gain to the controlled device. In a predetermined range of positions of the stick in which it is spaced to one side of neutral (or in such a range at each side of neutral) the system operates with low gain during displacement of the stick through a predetermined distance in either direction from a turning point to which the stick had been brought by displacement in the opposite direction. For all other displacements in that range the system operates with high gain. The method thus provides for fast, positive response to coarse stick movements but fine response to small trimming movements.

Abstract: A position control apparatus has a variable gain-type velocity amplifier (115) provided within a servo control circuit, and a low velocity sensing circuit (114) for sensing a predetermined low velocity of a motor (100) immediately before the motor is stopped. When the rotational velocity of the motor (100) drops to the predetermined low velocity immediately before stoppage during orientation control, the velocity amplifier is changed over in response to a signal from the gain of the low velocity sensing circuit (114), thereby raising servo loop gain.