Abstract: Two motors are used to provide motion control in a transport drive system. A primary motor, or a primary and secondary motor, provides primary power for accelerated motion. PWM signals are used to drive the motors according to predetermined fixed functions related to acceleration, deceleration and hold of a load. Alternatively, during onset of large or high speed moves, the primary and secondary motors are on in tandem. During deceleration of a move, the torque provided by the secondary motor is reversed, providing active braking and ensuring the drive train remains loaded wherein backlash is eliminated. During a driver hold phase, the primary and secondary motor push against each other to actively control positioning.

Abstract: The present invention relates to a method of controlling a numerically controlled machine tool having a plurality of feed shafts. Also, the present invention relates to a numerically controlled machine tool. According to the present invention, it is possible to solve conventional problems so as to realize highly accurate machining even when a moving body of the machine is moved at high speed. As the means for solving the problems, an appropriate command corresponding to a frictional force of the feed mechanism of the numerically controlled machine tool and also corresponding to a change in the weight of a workpiece is estimated by calculation, and the thus estimated command is outputted into the drive unit of the feed shaft motor so as to drive the feed shaft motor.

Abstract: A reference variable having a linear relationship with the angular position of a master axis is set, and a correspondence between this reference variable and the displacement of a slave axis is stored in a data table. One execution stage is specified by setting a starting reference variable and an ending reference variable from this data table. A desired sequence is assigned to a plurality of execution stages thus specified. The reference variable corresponding to the angular position of the master axis is determined, slave axis displacement data corresponding to the reference variable is read out, and the slave axis is positioned in accordance with the position of the master axis on the basis of this displacement data.

Abstract: With a memory access control portion without being intermediated by control of a CPU controlling an entire drive control of a motor, velocity data for setting velocity of a motor step by step are read out from a velocity table memory, and data value read out from the velocity table are converted by a time conversion circuit to time data, and based hereon a phase switching signal to operate the motor is generated in a phase signal generating portion. In addition, outputting of next data is requested to a memory access control portion in every time data output of a time conversion apparatus and occurrence of access to a next memory table is urged.

Abstract: A telescope system has an intelligent motor controller for accurately controlling telescope position to facilitate location of celestial objects and to precisely control the speed at which the telescope moves to facilitate tracking of celestial objects. An optical encoder utilizes two photodetectors to provide enhanced servo control of the telescope positioning motors, a calibration circuit eliminates a need to test LED's during assembly of the optical encoder and a brushless mount provides electrical communication to an altitude drive motor located in a fork thereof in a manner which mitigates problems due to undesirable wrapping of an electrical cable around the mount as the mount rotates in azimuth.

Abstract: An industrial process material flow within an industrial process is controlled by a process control loop that includes a process controller, a field device controller and a field device in the process as well as process variable feedback from the process to the process controller. Both the process controller and the field device controller, such as a valve controller, are fine-tuned so that their interaction is taken into account and controller parameters, which provide an optimal control loop performance are found. This results in a significant improvement in the control loop performance, i.e., in a lower process variability, as compared with the traditional tuning method, which does not take into account the interaction between the two controllers.

Abstract: In a state that a wafer stage is not positioned in the center of the Y-direction traveling range, thrusts Fa, Fb supplied from a pair of linear motors to a Y-direction stage are made different and the Y-direction stage is moved in the X direction so that moments Ma, Mb about the centroid of the Y-direction stage by the thrusts Fa, Fb cancel each other. Since the moments Ma, Mb about the centroid generated by the thrusts cancel each other and the thrusts do not act as forces for rotating the Y-direction stage, the Y-direction stage is not deflected in a yawing direction. Such a stage device as constructed above can prevent deflection in a yawing direction due to displacement of the centroid position of an object to be positioned or a stage and precisely move the object to be positioned to a target position.

Abstract: A servo controller capable of driving a single movable member by two motors with high loop-gain setting to obtain a quick response. A servo controller includes two position controllers associated with respective motors and a damping controller. Each of the position controllers has a position control section to output a velocity command based on an identical position command from a host controller and a position feedback value from an associated position detector, a velocity control section to output a current command based on the velocity command and a velocity feedback value from an associated velocity detector, and a current control section to output a voltage command based on the current command and a current feedback value from an associated current detector. The damping controller outputs a current command correction value for compensating an interference between the two motors based on the velocity feedback values from the velocity detectors for the two motors.

Abstract: A stage assembly (10) for moving a device (26) along an X axis and a Y axis includes a stage base (12), a device table (16), a stage mover assembly (18), a measurement system (21), and a control system (22). The stage mover assembly (18) includes a pair X guide movers (82) (84) and a Y table mover (87). The measurement system (21) includes a first X system (100) and a second X system (102). The control system (22) receives the position signals from the measurement system (21) and directs current to the X movers (82) (84) to move the device table along the X axis. The control system (22) can be designed to not skip any servo cycles during switching of position signals.

Abstract: A movable stage device, which has a stationary base, a movable stage and a linear motor, further includes a second linear motor which serves as a second driving device for imparting thrust to the movable stage and which is attached to the movable stage through the intermediation of an attachment plate. Both ends of a row of second drive coils are supported above the floor by support plates, which are independent of the stationary base and directly support the row of second drive coils above the floor in such a manner as to provide high rigidity, thereby attaining an improvement in speed and accuracy of positioning and avoiding a waste of energy.

Abstract: A device and method are provided to remove a wafer stage carrier carrying a wafer stage assembly from an exposure apparatus. The wafer stage carrier may be removably fastened to the apparatus frame of the exposure apparatus by any types of mechanical fasteners. The removal assembly includes a set of expandable supports and a set of removal supports. When the apparatus frame supports the wafer stage carrier, the wafer stage carrier hangs above a stationary surface, such as the ground. To remove the wafer stage carrier, the set of expandable supports is expanded until it reaches the ground and is capable of supporting the weight of the wafer stage carrier. At this juncture, the mechanical fasteners may be removed to allow the weight of the wafer stage carrier to transfer from the apparatus frame to the expandable supports.

Abstract: A hydraulic control system for controlling expansion and contraction of a cylinder. The cylinder comprises an extension chamber and a contraction chamber. The hydraulic control system comprises a first servovalve comprising a first pressure supply port and a first pressure discharge port and adapted to selectively communicate the expansion chamber with the first pressure supply port and with the first pressure discharge port. A second servovalve, comprising a second pressure supply port and a second pressure discharge port, is adapted to selectively communicate the contraction chamber with the second pressure supply port and with the second pressure discharge port.

Abstract: A stepper motor controlling apparatus having a storing unit storing driving data for generating a stepper motor driving phase signal in each of plural controlling circuits, which share the driving data in the storing unit, thereby decreasing the total amount of the driving data. It is therefore possible to minimize the required capacity of the storing unit required for the driving data.

Abstract: A motion control system comprises a motion unit having a motor connected to an encoder and an amplifier. The motion control system further comprises a scalable motion controller connected to the motion unit wherein the scalable motion controller receives signals from the encoder and outputs signals to the amplifier. The scalable motion controller comprises a plurality of dip sockets arranged for inserting and removing one or more motion control processors and a connector interface comprising a plurality of male and female connectors arranged for stacking a plurality of motion controllers.

Abstract: A circuit for the supplying power to at least three electric servomotors, such as servomotors used for an openable motor vehicle roof, each electric servomotor having a first terminal and a second terminal. The circuit includes a power supply, such as a voltage source having a first pole and a second pole, four independently actuable changeover contacts for individually activating and reversing the electric servomotors, whereby a pair of the changeover contacts are connected respectively to the first and second poles of the voltage source. A pair of the changeover contacts are assigned respectively to two of the at least three electric servomotors, and the first terminal of the first servomotor is connected to the first terminal of the third servomotor and the second terminal of the second servomotor is connected to a second terminal of the third servomotor.

Abstract: Apparatus, such as a wheelchair (10) is proportionally controlled by output signals produced by an X-Y input device (26, 58, 90, 100, 110, 360, or 370), which may be attached to head (90), a hand (112) or some other body component, and which may be actuated by tilting. The output signals are conditioned prior to application to the wheelchair (10).

Abstract: A stage assembly and support system are provided to stabilize a stage base, such as a wafer stage base or a reticle stage base, minimizing forces transmitted from the stage assembly to a stationary surface, such as the ground, and thereby preventing vibration of other parts or systems in a wafer manufacturing process. Depending of the applicable photolithography system, a reticle stage and/or a wafer stage are accelerated in response to a wafer manufacturing control system to position the semiconductor substrates. The jerking motions of the reticle stage and/or wafer stage cause reaction forces acting on the reticle stage base and/or wafer stage base. The reaction forces induce vibration to the stationary surface and surrounding parts of the photolithography system. The wafer stage assembly and support system according to this invention allow the reticle stage base and/or wafer stage base to move relative the stationary surface.

Abstract: An object of the invention is to provide a substrate transport apparatus which enables prompt transfer of a substrate, and a substrate processing apparatus incorporating this. A substrate transport apparatus of the invention comprises a transport arm (45, 46, 145, 146) for supporting a peripheral portion of a substrate (W) at at least two places on the peripheral portion, and transporting the substrate to a stage (7).

Abstract: A stage device includes a reaction-force-discharging structure in which a stationary member of a driving mechanism configured with a linear motor and the like disposed in a wafer chamber is connected to an external frame while maintaining the wafer chamber in a hermetic state. When a wafer stage is driven by the linear motor, a reaction force generated by driving the stage is applied to the stationary member. The reaction force is discharged to, e.g., a floor by the reaction-force-discharging structure via an external frame. For example, when the wafer chamber is set to a predetermined atmosphere of gas (including air from which organic substances and the like have been removed), the reaction force caused by driving the wafer stage can be discharged to the outside while maintaining the predetermined atmosphere. In an exposure apparatus using the stage device, accurate exposure is possible by reducing effects of vibration to the greatest extent possible.

Abstract: A ball joint gimbal system which provides for a precise line-of-sight stabilization of a gimballed mirror that rides on a ball and its associated support structure. The mirror is positioned by four braided lines. The brained lines are driven by four servo motor with each servo motor being coupled to one of four capstan shafts. Each of the braided lines is wound around one of the four capstan shafts. The braided lines are positioned by optical shaft encoders. The low inertia of the gimballed mirror and the positioning of the mirror by the braided lines result in an extremely accurate and fast scanning optical pointing system. Inertial gimbal stabilization of the line of sight to a target is by a stabilization algorithm utilizing body rate information from body sensors which are components of the missile for providing autopilot and navigation functions for the missile.

Abstract: Master and slave servo control circuits 2a and 2b are configured with servo controllers 3a, 3b, servo amplifiers 4a, 4b, servo motors 5a, 5b, feedback detectors 6a, 6b and error detectors 7a, 7b, and the servo motors 5a, 5b are mechanically interlocked and connected to a load. At a location upstream from the servo amplifier 4b, a torque command value selector 21 is provided; when the error detector 7a does not detect an error in the servo control circuit 2a, the selector switches so that the servo amplifier 4a and the servo amplifier 4b both receive a torque command value from the servo controller 3a, and when the error detecter 7a detects an error in the servo control circuit 2a, the selector switches so that the servo amplifier 4b receives a torque command value from the servo controller 3b.

Abstract: A stage apparatus includes a base having a reference plane, a stage mounted on the base, a plurality of static-pressure bearings forming a gap between the reference plane and the stage, a plurality of preloading mechanisms producing a preload between the stage and the reference plane, a guideless motor for driving the stage, and a controller for controlling driving of the stage in (i) at least one of a direction perpendicular to the reference plane and in a tilting direction by controlling at least one of the static-pressure bearings and the preloading mechanism, and (ii) in a direction within the reference plane by the guideless motor. Positioning of the stage in a Z-direction and in tilting directions can be carried out by electromagnets and air pads. Positioning in directions (X, Y, &thgr;) within a plane parallel to the reference plane of the base can be accomplished by guideless motors.

Abstract: An object is to reduce mutual interference between a plurality of sets of molds coupled to a common frame stand to improve the processing accuracy. A plurality of sets (e.g. two sets) of molds are driven by servo motors (6a, 6b). The servo motors (6a, 6b) are individually controlled by servo amplifiers (8a, 8b), respectively. A control portion in the servo amplifier (8a) calculates a current (I) so that the measured value (X) of the rotating position of the servo motor (6a) follows a directing value (X0) sent from a CPU through a pulse generator (9). A torque detecting/limiting portion (25) limits the calculated current (I) so that a limit value of the torque sent from the CPU through a DA converter (12) is not exceeded and sends it to the servo motor (6a) through a current amplifier (26). When the torque of the servo motor (6a) reaches the limit value after the molds come in contact, the directing value (X0) is rapidly advanced in the mold-losing direction.

Abstract: Position droops produced in main and auxiliary servo motors when main and auxiliary spindles are coupled to each other through a workpiece are obtained by adders, respectively, a difference between those position droops is obtained by a comparator before coupling, a divider divides the position droop difference by the speed of the auxiliary servo motor at the time of detecting the position droop to obtain a position droop difference per a unit speed. Then, after both the spindles are coupled to each other, a multiplier multiplies the position droop difference by the present speed of the auxiliary servo motor, and the adder adds that value to the position command to the auxiliary servo motor. With the above structure, even if coupling is made through the workpiece and synchronization drive is made, an excessive torque can be prevented from occurring, an influence of a change of the change gear ratio with a time is eliminated and a displacement occurring at the time of coupling is corrected.

Abstract: A wheelchair having a seat and a plurality of wheels for rolling the wheelchair along a ground surface. A plurality of legs are provided for supporting the seat. Each of the legs is positioned between the seat and one of the wheels. A plurality of struts are also provided. Each of the struts couples a first of the legs to a second of the legs. Each of the legs bears only compressive force in supporting the seat, and each of the struts bears only tensile force. A foldable wheelchair formed from a seat bottom and a seat back pivotally coupled to the seat bottom. The seat back is movable between a folded position and an unfolded position. The seat bottom has a back end formed from a first curved shape, and the seat back has a bottom end formed from a second curved shape. The first curved shape of the seat bottom is sized to mate with the second curved shape of the seat back when the seat back is in the unfolded position.

Abstract: A ball joint gimbal system which provides for a precise line-of-sight stabilization of a gimballed mirror that rides on a ball and its associated support structure. The mirror is positioned by four braided lines. The brained lines are driven by four servo motor with each servo motor being coupled to one of four capstan shafts. Each of the braided lines is wound around one of the four capstan shafts. The braided lines are positioned by optical shaft encoders. The low inertia of the gimballed mirror and the positioning of the mirror by the braided lines result in an extremely accurate and fast scanning optical pointing system. Inertial gimbal stabilization of the line of sight to a target is by a stabilization algorithm utilizing body rate information from body sensors which are components of the missile for providing autopilot and navigation functions for the missile.

Abstract: A synchronous controller that can perform high-speed, high-accuracy torque constant control even in applications wherein rapid load variation exists. The torque amount used for a control purpose of pressing a workpiece, etc., can be set as a torque offset correction amount and the torque offset correction amount is added to a torque command generated based on a speed command and speed feedback generated based on a position command and positions feedback.

Abstract: A control system for controlling a plurality of electrical devices (6) the system including a central controller (2) for controlling functions of the devices, a network (4) coupled between the central controller (2) and the devices, the network including a plurality of device drivers (10) for providing drive signals to the electrical devices, the number of drivers being less than the number of devices characterized in that the network includes intelligent devices (8) which enable communication through the network from the central controller (2) to the devices (6).

Abstract: A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween.

Abstract: Systems and methods are described for direct skew control and interlock of a gantry. An apparatus includes a gantry that includes a first member defining a gantry primary axis Z, a cross member defining a secondary axis X that is coupled to the first member via a trunnion, and a second member defining a gantry primary axis Z′ coupled to the cross member via an elastic hinge. A method for controlling skew on a cross member moved by a first and second driver includes moving the first and second drivers to a first position, measuring a resulting skew value, and correcting the skew on the cross member by moving the first driver and/or the second driver.

Abstract: An electronic control apparatus comprising: a movable control member; a positional servo loop means including at least one motor means and being operable to maintain the position of said control member at any one of a plurality of positions in the range of movement thereof in accordance with a demand signal; force detection means for detecting a force applied to said control member and for providing to said servo loop means a demand signal which varies in accordance with the magnitude of said applied force.

Abstract: A method of controlling the drive of computer-controlled transporting devices (2), in particular crane facilities with lifting winches and at least one mast supported on a moving frame on which are mounted shelf operator devices provided with load-carrying means and a lifting platform, and including a current control circuit (7), a drive control circuit with a speed control circuit (6), and a position control circuit (5), extend the possibilities of intervention when an instantaneous dynamic behavior of a transporting device (2) is calculated from an available data tree of a state and disruption monitor-regulator module (8) by using available measurement and setting values-containing information on a device dynamic and based on coefficient-characteristic fields, wherein the coefficient-characteristic fields incorporate structural details and/or dynamic characteristics of the transporting device and are determined by a regulator module (9) which performs an automatic self-teaching coefficient identification, p

Abstract: A drive device regulates a servomotor to one of a predefined position, a predefined speed, and a predefined current setpoint value. A control module is connected upstream from the drive device. A non-volatile memory where motor-specific data is stored is arranged in the housing of the servomotor. The housing has a data output through which the motor-specific data can be read. The motor-specific data is transmitted over a data line over which the feedback signals delivered by a sensor associated with the motor are also transmitted.

Abstract: A controller for a work transfer system, capable of performing precise positioning of feed bars during sole driving of the transfer system and simplified in structure to contribute to savings in installation space and cost. The controller has a cam angle detector mounted on a cam shaft for feed cams and controls servo motors for respective lift bars according to information which is related to cam angle of the feed cams detected by the cam angle detector and looked up in a motion table set by a transfer controlling PLC serving as a motion table setting means.

Abstract: An automatic machine has a plurality of axes driven by servo motors. The controller for controlling this automatic machine confirms that a compulsory power disconnection mode is engaged, releases the brakes and starts power supply to servo amplifiers. At a prescribed time after power supply to said servo amplifiers has started, the power supply to the servo amplifiers is halted compulsorily. Alternatively, the power supply to the servo amplifiers is halted compulsorily at a prescribed time after power supply to the servo amplifiers has started and after initial movement commands have been input to the servo controllers.

Abstract: A light valve has a pair of rotating vanes for controlling the cross section of a light beam passing between the vanes. The vanes rotate on corresponding shafts, each controlled by its own integral motor. Separate feedback control systems produce electrical control signals to each motor for rotating each shaft independently of the other to control the desired phase angles of the vanes. Error signals fed to variable gain amplifiers control the positions of the vanes. Whenever new commands are input to the variable gain amplifiers, amplifier gain is temporarily switched to a high gain mode, and after the phase angle of the shaft has stabilized, the amplifier gain is switched back to a low gain mode. The vanes are aligned on a common plane, and the vanes both rotate in an angular direction of rotation toward or away from the axis to reduce or enlarge the light opening between the vanes.

Abstract: A multi-axis motor controller is provided wherein connectors made to common specifications are provided on a multi-drive control unit of a motor drive control section operated by DC power received from a power supply unit, servo amplifier units and an interface unit. The connectors made to common specifications are used to interconnect the units by local bus cables and enable signals to be sent and received by serial transmission as desired among the units. This architecture simplifies the electrical interconnection among the units and lowers cost without sacrificing freedom of unit layout.

Abstract: A scanning exposure apparatus includes a projection optical system, a reticle stage for scanningly moving a reticle relative to the projection optical system a wafer stage for scanningly moving a wafer relative to the projection optical system, in a timed relation with the reticle scan movement, and a holding mechanism for holding the reticle on the reticle stage during the reticle scan movement. The holding mechanism includes a first mechanism for confining an end edge portion of the reticle in a scan direction and a second mechanism for pressing the reticle in a direction perpendicular to a pattern surface of the reticle.

Abstract: A gimbal drive module comprising an elbow (24) formed of composite material and having two legs. On one leg, elbow (24) includes an azimuth drive module (26). On the other leg, elbow (24) includes an elevation drive module (30). Azimuth drive module (26) and elevation drive module (30) include motors which when energized enable displacement of the respective legs in order to control the azimuth and elevation of elbow (24) to enable pointing of a structure, such as an antenna (18), as may be located on a second elbow outboard end (20).

Abstract: A positioning system for moving a device over an xy-plane has a drive mechanism with pivotable arms for moving a carriage over the xy-plane by driving it from one side. This drive mechanism allows the system to be made narrow along the other side.

Abstract: An arrangement for operating a brake of a vehicle has a controllable operating electric motor and a conversion device for converting the rotational movement of the operating electric motor into a translational movement of one or several brake element(s) which are in an operative connection with the conversion device. At least one additional electric motor is provided which can be controlled separately of the operating electric motor and has at least one additional conversion device for converting the rotation of the at least one additional electric motor into a translational movement of the brake element(s) which is independent of the translational movement caused by the operating motor and its conversion device.

Abstract: A controller for an industrial machine capable of monitoring a receiving circuit for receiving position information. A receiving circuit and an additional receiving circuit receive the same position information from a detector, and a monitoring circuit monitors a receiving state of the receiving circuit using position information received by the additional receiving circuit. A plurality of receiving circuits may be provided for respectively receiving different position information, and a plurality of additional receiving circuits and a plurality of monitoring circuits may be provided in a manner such that each additional receiving circuit and each monitoring circuit is associated with each receiving circuit. A single additional receiving circuit and a single monitoring circuit may be common to a plurality of receiving circuits.

Abstract: A communication apparatus and method provides communication in a controller of an industrial machine which is not affected by disconnection of cables, external electrical noise, nor complicated lead-around cable work. Communication between a numerical control device, as a main control unit, and servo amplifiers, as drive control units servo motors of a machine tool, is performed by way of infrared communication. The communication may take the form of input/output voltage commands, i.e. PWM commands, and feedback signals. By way of the infrared communication, lead-around cable operation, disconnection, and external electrical noises are eliminated, while simplifying machine tool layout design.

Abstract: For an orbital machining in which a spindle having a cutting tool attached thereto and a work to be machined are moved, by feed shaft control, to make a relative displacement to each other along a plane perpendicular to an axis of rotation of the spindle, such that a mutual interpolation motion is achieved between the spindle and the work, and a rotation angle of the spindle is controlled quantitatively and synchronously to have a predetermined correlation to the shaft control so that, at any angular position in rotation of the spindle, a blade direction of the cutting tool is maintained in a preset direction to thereby achieve a cutting into a configuration to be defined by an interpolation locus based on the mutual interpolation motion, there is effected a combination of feed-forward compensation for a follow-up delay in control of a motor servo system of a respective feed shaft and for a follow-up delay in control of a motor servo system of the spindle.

Abstract: The present invention relates to an electronically adjustable actuator for actuating a plurality of actuating elements, such as valves. A control unit is provided for generating actuating signals to cause each of the valves to move with one another in a start-stop motion in accordance with a predetermined moving pattern. The control unit would measure each potential at the outermost lowest position of the valve and at the outermost highest position of the valve. A device is provided for determining the present potential percentage value of the different valve between the maximum potential as well as the minimum potential. This different value is used to determine whether an actuating signal would be used to drive each of the actuating elements in the start-stop motion.

Abstract: A stop and jamming detection system in a stepping motor determines a parameter from the profile of an instantaneous motor variable and compares it to a reference value. A signal for the stop and jamming detection system is generated therefrom. Provided for this purpose is an analysis circuit which detects, as the instantaneous motor variable, the voltage that is induced in at least one unenergized winding of the stepping motor and is brought about by an energized winding of the stepping motor, and analyzes it as to whether the stepping motor is jammed or movable. In the analysis by the analysis circuit, a decision is made as to a hard or an elastic jam. With a hard jam, the stationary armature means that no voltage is induced, while with an elastic jam, because the step is not completed, the recoil of the armature into its original position induces an opposite-phase voltage peak which is detected.

Abstract: A robot control system is provided which controls a plurality of servomotors for moving a hand and articulated arms of a robot. The robot control system includes a plurality of position detectors, a motor control driver, and a serial communication path. The position detectors detect rotational positions of the servomotors and output the rotational positions in the form of serial data, respectively. The serial communication path is disposed between the motor control driver and the position detectors to transmit request signals provided by the motor control driver to the position detectors to request the position detectors to output the rotational positions.

Abstract: A method of and an apparatus for controlling a plurality of servomotors, in which one driven body is driven by one main servomotor and at least one subordinate servomotor. Synchronous control is performed with good response and high accuracy and repetitive control is performed with simple arrangement preventing interference between axes, and further operation mode of the plurality of servomotors is easily switched between coupled driving and independent driving. A plurality of servomotors comprises one main servomotor and at least one other servomotor subordinate to the main servomotor, and position control is performed on the main servomotor side while velocity control and current control are performed individually for each servomotor. A velocity command for the main servomotor is subjected to a position adjustment based on a position deviation between the main servomotor and subordinate servomotor and the adjusted velocity command is used for the subordinate servomotor.

Abstract: A servo control method is realized by connecting a high-speed serial communication interface with a microcomputer, a dual port memory and an IC for high-speed serial communication mounted thereon to an extended bus of a personal computer and by connecting between the high-speed serial communication interface and a plurality of servo controllers with a serial line in a multi-drop system.

Abstract: A slow-speed servomechanism includes a motor for driving a load; a direct drive transmission between the motor and the load; an incremental optical encoder connected to the load, the encoder having analog sine and cosine outputs; an analog to digital converter for converting the sine and cosine analog values to digital values; and a digital controller, connected to the motor and the analog to digital converter, for controlling the motor.