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 digital motor controller employs a digital signal processor to generate commutation commands that drive and brake a motor. The commutation commands are pulse width modulated. To avoid shoot-through, the digital signal processor automatically adjusts the widths of the pulses according to the amount of current being drawn by the motor. Motor speed is measured by taking the difference between consecutive samples from a position sensor and dividing the difference by the sampling time. The digital signal processor also closes position, speed and current loops. The commands provided by each loop are limited between upper and lower limits. Further, the digital signal processor automatically adjusts the upper and lower limits to compensate for changes in design characteristics due to variations in temperature. The digital motor controller can be used to control different motors having different design characteristics simply by reprogramming the upper and lower limits.

Abstract: A control system for an active hand controller, for example, uses a control stick connected to and controlled by a motor. Electronics are provided to control the motor to eliminate oscillations due to motor torque and high gain due to breakout at the control stick when the control stick is at about its null position. Both hardware as well as software implementations can provide position dependent dampening to the control sticks such that when the control stick is located about a null position, a higher rate of dampening is provided than when the control stick is located outside the null position, when a lower rate of dampening is provided. The system provides a stable active hand controller control stick without degraded force and feel characteristics of the system.

Abstract: A multi-system numerical control device which receives input commands for each system and is operative to control the speed and acceleration/deceleration of corresponding moveable objects, such as a motors. Each system has an interpolation unit and an acceleration/deceleration unit that is responsive to a corresponding time constant. A speed override device is operative to generate a speed reduction control signal that is applied to the interpolation unit to reduce the speed and to the acceleration/deceleration unit to reduce the time constant, thereby ensuring that the position relationship between the systems will not be lost even when override is applied.

Abstract: A generating device of a phase current instruction value for an A.C. servomotor and the generating method thereof, drives a synchronous A.C. servomotor. A sine wave, namely, a phase current instruction value for commutation of the A.C. servomotor driver can be generated by receiving as an interrupt the detection signal of a commutation sensor which detects the reverse electromotive force of the a motor at the microprocessor. The pulse position of the present since wave is.The pulse position of present sine wave is determined by the interrupt signal of the microprocessor. The motor is driven and controlled by converting by way of a D-A converter to an analog signal the data for generating a sine wave according to the increase or decrease of an encoder pulse.

Abstract: An improved method of controlling an electro-hydraulic control system by developing a motor control command in relation to the desired force to be exerted by an electric motor on a mechanical element whose displacement determines the hydraulic pressure. The control command is comprised of two magnitude signals. The first magnitude signal must be sufficient to exert enough force to overcome a static friction characteristic of the mechanical element, and the second magnitude signal is selected to achieve a desired average current or voltage over that control period. The time constant for the control command is less than the mechanical time constant of the system, but greater than the the electrical time constant of the system. The control command may be implemented by using either current or voltage control.

Abstract: A method and system for calibration of a primary signal processing path without interruption of signal processing utilizes a calibration signal processing path which is periodically used to process a signal concurrently with processing in the primary path. Any difference is compensated by gain adjustment in the primary path. In one form, a plurality of primary paths are sequentially compared with a calibrated path. The calibrated path is periodically checked using a precision reference and any error is corrected before comparison of the primary paths.

Abstract: A target position output unit outputs stop target position information of a driven member which is driven by a motor. A speed detecting unit outputs movement speed data of the driven member in accordance with a pulse from an encoder which generates a pulse in response to a movement of the driven member. A movement distance arithmetic operation unit performs an estimative arithmetic operation of a movement distance of the driven member until stopping when the motor is caused to stop immediately, in accordance with the last and current movement speed data. A stop position arithmetic operation unit adds the movement distance calculated by the movement distance arithmetic operation unit to the current position information of the driven member, thereby obtaining estimated stop position information of the driven member. A motor control unit controls the motor in accordance with a comparison result between the stop target position information and the estimated stop position information.

Abstract: A device for positioning control includes a movable stage; an acceleration sensor disposed on the movable table; a feedback loop for controlling movement of the movable table; and an acceleration feedback loop provided in relation to an acceleration signal from the acceleration sensor, wherein the acceleration feedback loop is provided as an internal loop to the feedback loop.

Abstract: A numerical control unit for controlling the position of a movable part, such as a machine table, in response to input machining information. The unit employs a servo control loop that detects the values of the position, velocity, acceleration and motor current for the movable part at predetermined times. Using such detected values and, on the basis of a representative spring mass system model, values of inertia, mass, viscous friction and sliding friction can be calculated and used for automatically optimizing the gain and offset parameters applicable to control of the machine.

Abstract: A velocity control apparatus in which velocity of a servomotor (12) is controlled by PWM-control of an inverter is so adapted that the gain (K') of an amplifier section (11) in a current loop is held constant by detecting the power supply voltage of the inverter.

Abstract: A servo control system (100) for controlling a prime mover (16) to position a load (12) to a commanded position in accordance with the invention includes a position sensor (14) for providing a load position signal representative of a position of the load; a controller for producing a control signal controlling activation of the prime mover to cause the load to be positioned at the commanded position including a first summer (20) for producing a first difference signal equal to a difference between a position command specifying the commanded position and the load position signal which is applied to a proportional amplifier (22) and an integrator (24), a second summer (26) for producing a sum of outputs from the proportional amplifier and the integrator and a third summer (104) for producing the control signal which is equal to a difference between the sum of the outputs and a signal proportional to the load position signal.

Abstract: By means of a timer and by setting the compensation for the lag error, the correctness of automatic drift compensation in a position-loop controller is enhanced and the accuracy of position control is also improved. In the present invention, a method and a device for automatic drift compensation in a position-loop controller are disclosed which enable accurate displacement control so as to avoid inadvertent shutdowns of the system.

Abstract: A servo-control apparatus is for generating a torque command conforming to a difference between a commanded velocity and actual velocity and controlling the velocity of a servomotor based on the torque command. The apparatus is provided with an observer (50) for reducing to zero an error between the actual velocity of the motor and estimated velocity and an error between the disturbance torque and an estimated disturbance torque. The estimated disturbance torque is inputted to a high-pass filter (70) to generate a corrective torque command, the torque command is corrected by a torque command correcting unit (15), and the torque command obtained by the correction is inputted to a servomotor (18) to control the velocity thereof.

Abstract: A numerical control apparatus according to the present invention is such that when a machine tool using a spindle motor (5) is commanded to perform a reference-point return operation and positional control of a tool or the like is carried out in response to this command, spindle reference-point return is made possible merely by applying the reference-point return command to a spindle amplifier (SPA) which drives the spindle motor (5). In accordance with the invention, a grid-shift quantity (P2) decided by the relationship between the spindle motor (5) and the object controlled thereby is set in advance on the side of the spindle amplifier (SPA) before numerical control unit (CNC) operation of the machine tool. The grid-shift quantity (P2) is added to position data (P3), which corresponds to the distance from a machine reference point to a machining starting point transferred before a fixed-position stopping command.

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: Disclosed are a traverse apparatus and an image recording apparatus including a rotary member for traversing a material to be traversed, a storage unit for prestoring rotation control data based on diameter data corresponding to a rotation angle of the rotary member from a reference position in its circumferential direction, a detection unit for detecting the rotation angle of the rotary member, and a control unit for controlling an angular velocity of the rotary member on the basis of an output from the detection unit and a content of the storage unit so as to make a traverse velocity of the material to be traversed constant.

Abstract: A signal which is dependent solely on the disturbance variable is selected by means of a filter and fed to a disturbance detector. This disturbance detector simulates the steady and alternating component (sine component) of the selected signal, as well as a signal (cosine component) phase-leading by 90.degree. with the latter signal. The correction signal required to exactly compensate for the disturbance variable is determined from the sine and cosine component of the periodic disturbance signal component by means of frequency-controlled function generators and a complex phasor calculation.

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

Abstract: 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 drive motor (1) with a shaft (3) drives a power takeoff shaft (5) via a planetary differential gear (2). The second input shaft (4) of the gear (2) is connected to a servo motor (10) via a worm gear (6). The worm (7) of the worm gear (6) is at least half as large as the worm gear (8). The pitch angle of the thread of the worm gear (20) lies between 5.degree. and 9.degree.. The rotational speed of the servo motor is controlled by a control (9). As a result of this design, a large controllable range of rotational speed is achieved with a lower power output from the servo motor. In this way, a large output power can be precisely regulated with little regulation effort. The drive has a high dynamic ratio and is suitable, for example, for cranes and elevators.

Abstract: A servomotor velocity control apparatus constructs a digital servo system including a compensating circuit (2) having a variable gain. The integration gain of the compensating circuit (2) is set and controlled by a gain setting unit (5) so as to be inversely proportional to estimated servomotor velocity computed from a velocity signal fed back in discrete fashion. It is possible to perform high-speed positioning based on an actual velocity signal which prevails when velocity is low.

Abstract: A method for acceleration and deceleration control of servomotors always brings out the maximum operating capability of a machine equipped with servomotors, such as a robot, NC machine tool, etc. and accurately moves a respective operating section of the machine, e.g., robot work point, tool, etc., along a commanded path. When a command is read from a program, the speed command value is divided by a maximum allowable (Am) of the machine, set previously, to determine a time constant (T) for acceleration and deceleration control (Step S2), and the time constant is divided by a sampling period to obtain a number (n) of times of commanded speed sampling (Step S3). The servomotor is driven at a controlled speed after the acceleration/deceleration process. The controlled speed is obtained by dividing a sum of a commanded speed of the current sampling period and commanded speeds sampled in the previous (n-1) periods preceding the current period, by the number (n) of times of sampling.

Abstract: The robot control apparatus according to the present invention is so adapted that, with regard to all kinds of motions commanded of a robot, the maximum velocity and time constant conforming to the type of robot motion can be designated for respective robot control axes (3) by a controller (1) which includes a selection table memory (4).

Abstract: The present invention is provided to suppress mechanical resonance which is likely to be generated in a mechanically driven and controlled apparatus such as robots, machine tools, etc. due to their low rigidity. In order to achieve this object, the present invention uses an adaptive filter which changes its cut-off frequency or notch frequency in response to a change in the natural oscillation frequency caused by a change in position and orientation of and load acting on the machine.

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

Abstract: A servo control system has a motor for a control and a device for commanding target distance and velocity of movement of the control so as to actuate the motor in accordance with commands from the commanding device.

Abstract: The inventive system for controlling a working shaft includes a layout for the time to number conversion, wherein a divider is provided to divide with use of a pulse rate outputted from the memory storage, and the shaft driver is operated by output from such a divider and is thereby controlled with use of the data stored in the memory storage. Concurrently, by introducing the counter outputs indicating the time scaling into the addresses of a memory sector, the memory sector is arranged to output varying speed data corespondent to the time scaling data. Thereby trailing actions of the working shaft to trace a given locus are determined by data stored in the memory storage, which enables a complex real time control to be feasible by the inventive simple control system, wherein, as required, a change in the control specification is simply made by a change of data in the memory storage.

Abstract: To control the draw exerted on a web which is being fed to the rolls of a web processing machine, a strain wave gear power transmission device has its power input shaft driven by the main drive shaft of the machine and its output shaft coupled to the rolls including the nip rolls of the machine which draw the web. The wave generator (W.G.) shaft of the device is driven continuously in a single direction and at a higher rotational speed relative to the power input shaft. Encoders provide concurrent pulses at rates indicative of the main shaft and W.G. shaft speeds. The ratio of the pulse ratio is determined and compared to a stored value which corresponds to percent of draw desired. Any resulting error signal is used to change the speed of the W.G. shaft and output shaft. High encoder pulse rates provide for resolving small speed and draw errors. The output shaft of the transmission drives groups of rolls of the machine by way of a plurality of belt drive systems.

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: 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 topology for a servo motor carriage drive includes a strain gauge coupling the carriage to a motor-driven belt to provide a signal representative of the flexure of the belt. A velocity signal is taken from a linear encoder on the carriage. These signals are used in inner and outer feedback loops for controlling the velocity of the carriage as it travels along a predetermined path.

Abstract: In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus having a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output of the driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

Abstract: In a method for numerical position control of motordriven shafts whose rotations are to be synchronous with one another under a certain transmission ratio a control loop is provided for each shaft. A speed setpoint, weighted with the corresponding transmission ratio, is applied as a position setpoint per unit of time simultaneously to the control loops of the respective shafts. If the actual speeds of the shafts differ from one another due to a disturbance within the controlled system, the difference between these actual speeds is used to readjust the speed and the position within the speed controlled section of one of the control loops.

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 velocity control apparatus according to the present invention controls the velocity of the distal end of a load such as a robot upon estimating the velocity of a servomotor from a detected position signal. In order to raise the speed at which estimated values of position and velocity are computed by an observer, a model serving as the object under the control of the observer is reconstructed as a simplfied servo-control system, and an estimated value (V.sub.L) of the velocity of the distal end of the mechanical load is computed upon regarding a difference value in the amount of rotation of the servomotor every fixed period as being the rotational velocity (V) thereof.

Abstract: A servo circuit controls the rotation of a drum motor to rotate a rotary head drum having a frequency generating circuit for generating a frequency signal corresponding to the revolution speed of a drum motor, a cycle detector circuit detects a cycle of the frequency signal from the frequency generating circuit, and a detector circuit speed deviation between a detected signal from the detector circuit and a reference signal to produce a first circuit generates speed deviation signal, a first circuit for generating a first circuit generates first rotation control signal based on the speed deviation signal, and a second circuit produces a second rotation control signal based on phase difference data obtained by integrating the speed deviation signal. An adder circuit adds the first and second rotation control signals to produce a rotation control signal which is supplied to the drum motor to stably rotate the rotary head drum.

Abstract: A digital servo system for causing a mechanical element (48) to track a desired path and hold various positions along the path and employing a lead/lag integrator (18) in parallel with a feedback control loop. The input to the integrator (18) is switched between velocity (V.sub.EK) error during pathtracking and position error (E.sub.K) during holding to increase the resistance of the mechanical element (48) to position changes caused by outside forces during both pathtracking and holding. The integrator function employed uses a term (U.sub.integrator(k-1)) representing a previous integrator output value to assist in smoothing perturbations caused by switching between position and velocity error.

Abstract: The actuator has a displacement detector and is driven intermittently through a given displacement. A mean amount of drive signals per one intermittent drive such as a mean duration of drive signals and a mean number of drive pulse signals is calculated through a predetermined number of intermittent drives. The mean amount of drive signals is intermittently applied to the actuator for a given number of intermittent drives without the displacement detection. After the given number of intermittent drives by the calculated mean amount, another intermittent drive with the displacement detection is carried out. At this time, the total duration of the drive pulse signals or number of the drive pulse signals outputted until the completion of the given displacement is compared with the calculated mean amount.

Abstract: A tachometric device is provided with a D.C. electric motor a shaft of which drives a pair of permanent magnets to rotate. A first permanent magnet controls a speed indicator unit; a second permanent magnet is rotatably mounted within a winding the terminals of which are connected to a negative feed back circuit for controlling the speed of the motor.

Abstract: A servo control system has a first integrator to which the speed of a servomotor is fed back and a second integrator to which the speed of a mechanical load of low rigidity is fed back. The speed of the servomotor and the speed of the mechanical load driven by the servomotor are simultaneously reflected at a prescribed ratio on a transfer function of the servo control system, whereby appropriate servo control is made possible for the mechanical load to achieve speed control having a quick response and stability.

Abstract: Disclosed is a servo control system for a disk drive actuator using a bi-directional (Up/Down) Difference Counter along with a control circuit therefor which signals the counter each time a "rest position" is passed, indicating whether this passage is toward, or away-from, the destination track.

Abstract: An analog servo system suitable for accurately controlling the carriage speed of a high speed printer over a relatively wide range. The system includes an analog tachometer with circuit means which enables the tachometer to operate in either a high gain mode (used at normal or lower carriage speeds) or a low gain mode (used at higher carriage speeds). The tachometer gain mode (or "electronic gear") is controlled by an external command signal such as a single bit supplied by the control microprocessor of the printer. The state of the command signal controls a time constant in the tachometer circuit means which determines the gain mode.

Abstract: To control the intermittent movement of a conveyor belt or carousel, fitted with molds, in a unit for the manufacture of moldings from multi-component plastics, an intended/actual value comparison of the speed of the conveyor belt or carousel as a function of the distance of the molds from fixed devices for filling, demolding and similar operations of the molds is carried out so as to provide control signals for the electric motor. The actual value is determined from a signal voltage generated in correspondence with the rotary movement of the electric motor. The signal voltage is additionally, and in parallel to the speed regulation, converted to electric pulses which are summed in their time sequence, as a function of the movement steps of the conveyor belt or carousel, and are compared with a predetermined master function which can be varied.

Abstract: A rotation phase control device which synchronizes the rotation phase of the rotor of a motor with a reference signal and which has a steady-state characteristic compensating circuit improves the starting characteristic of the motor by compensating characteristic control apparatus for varying the compensating characteristic of the compensating circuit based on whether or not the rotation phase of the rotor is within a predetermined synchronization range relative to the reference signal.

Abstract: A feedback servo positioning system for motor 13 is configured under the control of microprocessor 27 either as a position feedback servo for small displacement demands or an acceleration feedback servo for large displacements. In the latter role, the processor determines an intermediate position (e.g. mid point), accelerating the motor at maximum acceleration rate until the intermediate position is reached, and then calculates the deceleration rate required to stop the motor at the demand position. During deceleration the instantaneous position and velocity are monitored to update the optimum deceleration rate to compensate for variations from the initially computed value due to friction and other measurement errors.

Abstract: An inductive load 1, more specifically a direct current motor, is fed by a direct current source through a semiconductor regulator which contains two parallel switching controllable semiconductor rectifier elements with identical conduction direction which in turn are in series with a respective one-half of center tapped output autotransformer. Parallel to the semiconductor regulator is an additional and identical semiconductor regulator. The center tap points of both semiconductor regulator autotransformers are connected with the terminals of a third output autotransformer which is similarly center tapped, whereby the center tap point of the third output autotransformer is connected to a terminal (+) of the inductive load. The control assembly is made in such a manner that it produces clock frequency signals with identical control levels for both semiconductor rectifier elements; however, these signals for the two parallel switching arrangements are, electrically offset by 90 degrees.

Abstract: Synchronous or coherent error appearing as one or more FM sidebands in the high frequency pulse signal of an incremental position encoding digital tachometer or the like and in an error signal having a magnitude representing the difference in velocity between that indicated by the high frequency signal and a desired velocity is suppressed in the error signal by a coherent error correction signal of varying magnitude which is combined with the error signal, is generated as a function of mechanical angular position and is identical from cycle to each cycle of the tachometer for the same mechanical angular position.

Abstract: Computer-augmented electromechanical system is provided for controlling the tongs of a servomanipulator. The mechanical tongs are motor-driven through the remote slave arm of the manipulator, and the motor control current is supplied by a position sensor which senses the position of a spring-loaded trigger in the master arm handle on the manipulator. The actuator for the tongs provides the operator with artificial force reflection in a unilateral force-force control loop.

Abstract: For the controlled slowdown of a translatory or rotary machine part to arrest same in a predetermined stop position of an entrained load, the part being driven by an electric motor against a countervailing torque, a trial run is used with a constant motor torque (less than the countervailing torque) to determine a deceleration characteristic under conditions duplicating those of a subsequent production run. The deceleration characteristic is registered in the form of discrete positional values detected at successive instants, these values being stored in a memory for consecutive readout at corresponding instants in a production run and comparison with actual load positions to provide an error signal for the adjustment of the motor torque. A specific embodiment serves to control the final position of a rotary workpiece holder in friction welding.