Abstract: A motor load switching system in which a single motor with a single control circuit drives a plurality of different-sized loads by sequentially switching from one load to another. A parameter storage device stores a plurality of parameter sets which are optimized for respective loads. In response to a load switching command, motor control device selects a corresponding parameter set from the parameter storage device and controls the motor according to the selected parameter set. Simultaneously, a load switching device couples the motor with a new load selected from the plurality of the loads.

Abstract: A multi-rate positioner system (50) receives unpanelized positioning commands from a database storage subsystem (64), profiles the commands (72) into a half-sine positioning signal, and further processes the signal into a low-frequency positioning signal (LFP) and a high-frequency positioning signal (HFP) for actuating respective slow (56, 58) and fast (54) positioners to target locations on a workpiece (62). The slow and fast positioners move without necessarily stopping in response to a stream of positioning command data while coordinating their individually moving positions to produce temporarily stationary tool positions (140) over target locations defined by the database. The multi-rate positioning system reduces the fast positioner movement range requirement while providing significantly increased tool processing throughput.

Abstract: A control method for a servo system capable of adjusting softness to provide a robot with a soft floating function for each axis of a rectangular coordinate system. A force (Fx, Fy, Fz) acting on a tool center point in the rectangular coordinate system .SIGMA..sub.0 is obtained using a position error in the rectangular coordinate system .SIGMA..sub.0 and set parameters (Kx, Ky, Kz). The obtained force (Fx, Fy, Fz) is transformed into data (Fx.sup.(n+1), Fy.sup.(n+1), Fz.sup.(n+1)) in a tool coordinate system .SIGMA..sub.n+1, using posture data of the robot. Further, according to the Newton-Euler method, premising (Fx.sup.(n+1), Fy.sup.(n+1), Fz.sup.(n+1) =(fx.sup.(n+1), fy.sup.(n+1), fz.sup.(n+1), a torque Ti for each axis is calculated to obtain an input value Ei=Ti/(Kp.multidot.Kv) for a position loop.

Abstract: A numerical control device according to the present invention progressively analyzes a machining program stored in a storage device by one program block or by a plurality of program blocks, computes a migration rate and a feed speed in each axial direction from an instructed moving position of a tool and a feed speed of the tool in an interpolating section, outputs a positional instruction to an object for control for each given cycle, and has a sampling time interval computing section for computing a sampling time so that a number of instruction pulses for each sampling time under a given feed speed is kept at a constant value when a migration rate for 1 block computed in the interpolating section is divided to a number of pulses for each sampling time, and an interruption controlling section for setting a variable sampling time.

Abstract: Disclosed is a feedrate controlling method and apparatus for controlling a wire-cutting electric discharging machine (WEDM) to operate at optimal feedrate. In the apparatus, a discharge frequency counter is used to count the frequency of normal discharge and the frequency of abnormal discharge, from which two performance indexes: stability percent (STB) and efficiency percent (EFF) are obtained. These two performance indexes allow the apparatus to use a decision table to obtain an optimal feedrate variation used to change the current feedrate so as to operate the WEDM with maximum stability and efficiency.

Abstract: To enable the free setting of an acceleration and deceleration pattern free from the amount of movement and the movement time a numerical control method controls the operation of a controlled object by a target function. The method which computes the target function Y(t) by an amount of change .DELTA.Y.sub.t, a normalized target function y(t), and correction values .beta., .delta.

Abstract: A threading apparatus is capable of eliminating a rise delay in the feed velocity due to friction resistance and can perform high-precision threading even in high-speed tapping. A feed servo amplifier is controlled to operate using one of a plurality of gains. A gain setter sets the plurality of gains, which include a high gain, which is high enough to overcome static friction resistance, and a normal gain. A gain changer selects one of the plurality of gains for the feed servo amplifier. In particular, the gain changer selects the high gain during a start period of tapping operation and then selects the normal gain after the start period. Therefore, a rise delay in the feed velocity due to friction resistance during the start period of the tapping operation can be compensated for. After the start period, the normal gain is selected. Thus, high-precision threading can be performed over the course of the tapping operation with no errors.

Abstract: The invention pertains to a process for the two-dimensional determination of a work-area contour for collision monitoring of numerically controlled lathes. Disclosed is a process for the two-dimensional determination of a work-area contour wherein the work-area contour for collision monitoring can be determined at a reasonable cost in computer power: first a safe zone is defined in the form of a segment contour. Defined also is a segment contour that describes the contours of the tool and tool fixtures. Following that, the contour vertices both of the safe zone and of the tool segment contour are defined and stored as coordinate values. The contour vertices thus derived for the safe zone and tool segment contour are overlaid in pairs and for each overlay the coordinate values of a reference point are calculated. From the coordinate values of the segment contour those coordinate values are chosen which when properly combined yield the work-area contour.

Abstract: A method of obtaining a force of each axis of a robot from the product of positional deviation and positional gain. A vector having components of the forces as many as the number of axes is defined and transformed into a vector on the base coordinate system. Based on the vector, a normal line vector on the profiling object plane is determined. The attitude of the robot is controlled so that the direction of the normal line vector may coincide with the Z axis of the tool coordinate system. Next, the positional gain of each axis, which would serve to make the force in the direction of the normal line vector constant, is determined, with the position deviation fixed. Further, the tangential direction of the moving path at the position is obtained, and the moving target position of the robot is determined in that direction.

Abstract: An apparatus for preparing NC data is used in machining an involute curve on a workpiece by relatively moving a tool and the workpiece along mutually perpendicular first and second axes encompassed within a plane while relatively rotating the tool and the workpiece about a third axis which is perpendicular to the plane. In the apparatus, there is provided involute curve definition devie defines the involute curve based upon input parameters, machining point calculation means calculates a series of machining points on the involute curve, and tangential line calculation device calculates a tangential line which connects the involute curve at each of the machining points.

Abstract: A control for machine members propelled at plural points along their length to move linearly transverse to member length determines and eliminates skew of the driven points. Skew is determined from position indicated by position transducers associated with the driven points. Various types of position transducers are accommodated, including encoders having outputs from which member position can be determined only with reference to marker outputs of the transducer. For such encoders, the control effects velocity controlled motion to detect position. Skew is eliminated by relatively moving the driven points by the magnitude of the skew.

Abstract: A numerical control apparatus for controlling a cutting machine for cutting a workpiece according to a predetermined tool path wherein the tool path is defined relative to a coordinate system by a cutting program. The numerical control apparatus includes circuitry for generating data representing a coordinate system guide and a graphic display device for displaying the coordinate system guide so that a program designer can determine whether the tool path is defined relative to a desired coordinate system.

Abstract: Disclosed is a servo control method and apparatus for use on discharging machines to control the discharging conditions on working piece. In conventional art, feedrate control is based on the average of the discharging voltage between the discharging electrode and the working piece, which takes the off-time period into account; and in the condition of a long off-time period, the average voltage will be lowered as to affect the stability of the discharging process. The servo control method and apparatus according to the present invention disregards the off-time period and takes only the ignition voltage and discharging voltage into account such that the stability of the discharging machine will not be affected. Furthermore, during discharging, the servo control method and apparatus is capable of detecting whether there is a short-circuit condition and adjusting the average voltage accordingly so as to quickly remove the discharging electrode from the working piece.

Abstract: A tool-receiving system 14 displaceable in one, two or three dimensions is mounted on a tool support 6 displaceable in two or three dimensions relative to the 2-dimensional or, e.g., 3-dimensional processing or drawing surface. System 14 is amenable to higher acceleration than the tool support 6. A device 30 coordinates the superposed components of displacements of tool support 6 and/or tool-receiving system 14 in such a way that the resulting maximum acceleration of the overall equipment corresponds at least to the acceleration of the system 14.

Abstract: An industrial-robot teaching program is prepared off-line without using a robot. Then, cameras serving as vision sensors are mounted on a wrist flange of the robot to obtain measured position data for a teaching point P1. The teaching point P1 is on a workpiece in a sensor coordinate system and is detected by the vision sensor. The position data for the teaching point in the teaching program is converted into position data in the sensor coordinate system. Next, an error of the robot wrist flange coordinate system is estimated in accordance with a difference between measured position data for the teaching point and converted position data in the teaching program. Then, the teaching point data included in the teaching program is corrected based on the estimated error of the robot wrist flange coordinate system. The vision sensor may also be attached to an end effector of the robot.

Abstract: A screw shaft feed mechanism includes a screw shaft (25) rotatably supported by a frame (19) and extending in a shaft feed direction of a work table (shaft fed base) (1); a nut member (39) rotatably supported by the work table (1) and engaged with the screw shaft (25); a screw shaft drive motor (29) for rotating the screw shaft (25); and a nut drive motor (57) for rotating the nut member (39), wherein both screw shaft driving means and nut driving means are provided with a motor having a device detecting a rotational angle of a motor shaft, respectively.

Abstract: The invention relates to a method for verifying the performance accuracy of an NC machine by comparing a desired circular path with the actual circular path describing the actual movement of the machine and used in an NC machine having at least two servo control loops each of which is provided with an axis actuator for guiding a carrier in accordance with a position reference signal describing the desired movement path, and a path measuring system to record and feed back the position of the carrier. In this case, the actual circular path R.sub.M is formed from the position signals (x.sub.M) supplied by the path measuring system (33, 43) and, preferably, each of the position signals (x.sub.M) measured by the path measuring system (33, 43) is compared with the associated position reference signal (w.sub.NC).

Abstract: A machine tool controlling apparatus and method wherein the current operation is in a normal operation mode or in a positionly synchronized operation mode in which a spindle and a subordinate axis are positionly synchronized. If it is determined that the current operation is in the positionly synchronized operation mode, transfer function models for the spindle and the subordinate axis are extrapolated into a position instruction issued to the subordinate axis.

Abstract: A numerical control unit for a machining apparatus which operates under the control of a machining program comprising a plurality of blocks, such blocks being adapted to define a command or instruction for specifying and automatically controlling the relative movement between a machine tool and a workpiece with respect to one or more of linear and rotational axes, and being modifiable at starting-point and end-point areas in a single block to specify desired variations in relative movement or feedrate. The feedrate may be controlled on the basis of preset rules within a single block without dividing a machining path into a plurality of blocks for controlling the feedrate, the preset rules being changeable by an operator whereby his machining know-how can easily be incorporated into the machining program.

Abstract: A numerical control apparatus which reduces a cycle time by executing the movement command of a next block without temporarily stopping the movement of a workpiece even if a skip signal is input. Upon receiving the skip signal SS output from a sensing device, a skip signal sensing device determines the present position of the workpiece, stores the position in a memory device and outputs a skip completion signal AS. Then, an acceleration/deceleration distribution device carries out pulse interpolation of a present block and outputs a distribution completion signal ES on the completion of the movement. Further, a preprocessing distribution device, having received the skip completion signal AS, determines an amount of movement of a next block from the present position of the workpiece and preprocesses the next block of the machining program.

Abstract: A tracing control system for tracing a groove counter can easily measure the groove contour formed on a three-dimensional model surface. A tracer head is provided with a stylus having a size enabling the stylus to slide in a groove formed on the model surface in the state that the stylus receives a load from three axial directions. Amount of displacement sensing means senses the amount of displacement of the stylus. Displacement vector calculation means calculates the displacement vector of the stylus based on the sensed amount of displacement of the stylus. Movement control means controls the positional movement of the tracer head so that the displacement vector is equal to a predetermined vector value at all times. Position sensing means senses the present position of the tracer head. Data creation means creates digitized data based on the sensed present position of the tracer head and the amount of displacement of the stylus.

Abstract: A control method and a control apparatus for a robot, in which an operation line position is detected by a sensor, and real-time tracking of the operation line is performed by correcting a taught path with the use of an output signal from the sensor. The weld line position in a region on the travel direction side is sensed by the sensor supported by a robot hand to obtain the position data of sensed point kSm. After the sensed data is converted into coordinate data s(k, m) of a work coordinate system, processing is performed by using data of taught path segment PkPk+1 to which the sensed point kSm belongs. The processed data is stored in a buffer memory of ring memory type together with the coordinate data of the sensed point. The necessary data is read from the buffer memory just before the execution of tracking, to determine the tracking target point in a short period of time.

Abstract: A method of tracking a robot with respect to a circularly moving workpiece W. When a workpiece on a disc-shape conveyer remains stationary at a reference position W0, positions P0 and Q0 are taught to the robot in a stationary coordinate system .SIGMA.0 and the robot is placed on stand-by at a position A. The angular displacement of the disc-shape conveyer is detected by a pulse encoder and counting of the output pulses starts when the workpiece W arrives at the reference position W0. A CPU of a robot controller reads the counted amount in a short cycle and transforms it into a rotation amount .theta. of the conveyer from the reference position. Updating of matrix data for setting a rotary coordinate system .SIGMA.rot based on the rotation amount .theta. is repeated.

Abstract: A computerised motion control apparatus for controlling a plurality of degrees of freedom of the positioning and orientation of a camera. The apparatus including a dolly (71) positionable by drive means along an extensible track arrangement (72), having a camera (73) mounted thereto and provided with motors to orientate the camera (73) by varying its pan (76), tilt (75), and roll (74). An operator interface device (15) is used to define position and velocity characteristics of the desired motion of each of the camera's axes of motion and a motor driver module (69) calculates a parametric cubic polynomial representation of the desired motion curve. The calculated coefficients of the motion curve parametric cubic polynomial representation are easily stored and used to regenerate the values of the curve for the purposes of display and providing motion curve values for each axis of motion of the camera. These calculations can be performed upon command and in real-time.

Abstract: A numerical control apparatus in which tool feed can be stopped at the same time as machining is completed. An interpolating device in a numerical control apparatus interpolates a pulse signal HP supplied from a manual pulse generator and outputs an interpolated pulse signal CP so that the tool is moved along a designated shape prestored in a graphic data memory device. An axis control circuit generates speed commands for respective axes in response to the interpolated pulse signal CP and sends the generated commands to a servo amplifier. The servo amplifier delivers a drive current I to energize servomotors mounted on a machine tool. A load determination device detects the drive current I from the servo amplifier and determines whether the detected current I decreases at a given ratio. When the drive current I decreases, for example, by 5%, a drive stop signal S is supplied.

Abstract: An actively controlled, pneumatically-actuated constant force device (CFD) which may be fixed to a stationary mount or moved in three-dimensional space proximate a work surface. The device applies substantially constant force from an actuator, through a linkage, to a tool in contact with a work surface, e.g., a drilling, grinding or finishing tool, or a laminating roller. A processor provides closed-loop control of estimated tool force applied to the work surface, regardless of tool orientation. CFD compliance and response time may be altered by adjustment of gas pressures in a pneumatic cylinder. Active control of estimated tool force includes processing of information on actuator force, actuator orientation, tool and linkage weight, and actuator motion, as well as work surface irregularities.

Abstract: A tolerable feed rate is calculated to cause mechanical shock not exceeding a tolerable level in an arcuate machining based on the radius of the path of tool movement at arcuate machining portions and the predetermined tolerable acceleration. A deceleration start timing is set by reference to the end of an arcuate machining and the predetermined deceleration so that the feed rate is lower enough to maintain the tolerable mechanical shock at the end of an arcuate machining. An optimum feed rate is set for arcuate and completely circular machining based on the classification judgment of the arc or complete circle.

Abstract: A method for efficiently interpolating sub-span position commands for control of a machine member. The method includes storing a set of coefficients defined by a parametric function relating member position and time, calculating the distance between a target coordinate axis position command and a current coordinate axis position command, generating first and second command modifiers from the stored coefficients, the calculated distance, and a current coordinate axis position command, and summing the current coordinate axis position command and the first and second command modifiers to generate a subspan position command.

Abstract: Spaced cutting tools, each having a plurality of linear axes and a rotational axis, are supported with a conveyor carrying successive parts past the tools. The tools include positioning motors and are positioned by a computer driven system including a controller and a tool program for positioning the tools to sequentially cut each part. Separate computer boards each include a memory unit and a CPU for coupling to individual positioning motors for each tool. The controller downloads the program for particular axes to the board for the tools. A positioning sensor is coupled to each tool axes and connected to the computer input for monitoring each tool position. All tools are simultaneously positioned using an initial fast constant speed feed followed by a varying slow speed, with a closed loop control, within a fixed time period.

Abstract: An apparatus and a method for discriminating position information in a position control system. The apparatus includes a position detector for detecting information regarding a current position of a motor, a position counter for counting the motor current position information from the position detector at a fixed period, a central processing unit for reading a counted value from the position counter, comparing the read value with a normal position command value stored therein, compensating for a difference value as a result of the comparison and outputting a position control value based on the compensated value, and a digital/analog converter for converting the position control value from the central processing unit into an analog signal and outputting the analog signal as a position control signal for the motor.

Abstract: A method for controlling a servomotor, in which the differences in dynamic characteristics among machines are absorbed by the controller so as to substantially equalize the response characteristics of the machines. An advance smoothing processing is executed before each position-speed loop processing cycle. The position feedforward amount FFp is calculated according to the following equation:FFp=.alpha.{(1-K) SMD.sub.0 +kSMD.sub.1 }.Where, SMD.sub.0 represents a smoothing data of the present cycle; SMD.sub.1, a smoothing data of the preceding cycle; and .alpha., a position feedback coefficient. The parameter k given in the above equation is adjusted to adjust the response characteristics of the individual machines, as well as the response characteristic of the mechanical system including controller with respect to an operation command. With this adjustment, the dynamic characteristics can be equalized between two or more machines even when such machines are simultaneously interpolated.

Abstract: An numerical control (NC) device capable of machining a workpiece with high accuracy by accurately commanding a feed speed of a tool, even if a sudden change occurs in an actual speed of a spindle motor. If a rotational speed of a spindle changes, a change amount calculation/storage device calculates and stores a change amount on the basis of the rotational speed already detected. A rotational speed detected by a rotational speed detection device is corrected thereafter according to the change amount, and a proper feed speed is commanded from a feed speed control device. If thread cutting is carried out by employing the NC device, the tool feed speed is commanded in proportion to the actual speed of the spindle motor, and therefore, even though the rotational speed of the spindle motor is lowered at the moment the workpiece is started to be subjected to thread cutting by the tool, a move command signal with a proper tool feed speed is outputted.

Abstract: A robot carrying a milling cutter or other multi-axis machine cuts a physical model and is directly driven in real time from a CAD generated mathematical model. The path planning is carried out in parametric space but with velocity constraints in the machine coordinate space. The method will generate proper points in parametric space and then map to machine space to minimize interpolations needed by machine controller to improve tracking accuracy while achieving the desired cutting velocity. Point data is computed by the microcomputer and transferred to the machine controller continuously while the machine is cutting. Long pre-cutting computation times are eliminated.

Abstract: An acceleration and deceleration controlling apparatus in which a positional moving amount supplied from a host is converted into an accumulated value of absolute positions by two serially connected accumulators to be output to a first stage of a buffer registers 4. A switch 5 is provided to read out a value from a desired register among the buffer registers 4. The switch 5 changes the substantial number of stages of the buffer registers 4. At the same time, by correspondingly switching the divisor of the divider 7, the time constant for the acceleration and deceleration are desirably changed, which contributes to optimize the acceleration and deceleration time and to reduce the processing time.

Abstract: A numerical control system for controlling a machine tool including a control device for controlling the machine tool; external portable storage device for storing data; a disabling device for disabling the control device; a read/write device, operable when the external portable storage device is manually coupled thereto, for reading data from the external portable storage device and for writing data to the external portable storage device; and a determining device for determining whether the external portable storage device is coupled to the read/write device.

Abstract: A control unit for an injection molding machine comprises a position feedback control system 41, a pressure feedback control system 42, and a velocity minor feedback control system 43 which is used in common to the position and the pressure feedback control systems 41 and 42. A minimum value selector 30-3 selects a smaller one of manipulated variables supplied from the position feedback control system 41 and the pressure feedback control system 42. During pressure control, a position pattern follower 30-4 controls the operation of a position pattern generator 24-2 so as to restart generation of a position pattern at any time.

Abstract: In a method of operating a numerically controlled machine tool having tools for processing workpieces, the paths to be calculated for the movements of axes of the tools are not calculated in real time on the processing of a workpiece, but are calculated previously by a programming unit before the processing of the workpiece, and are stored by a compiler into an object file for each axis the movement of which is to be controlled. All the object files run in synchronism on the processing of the workpiece under the timing of a central clock.

Abstract: A numerical control system controls a plurality of axes with a plurality of channels (10.about.40). A plurality of spindles (61.about.64) or automatic tool changer controllers (51, 52) are selected and controlled by the channels (10.about.40) according to machining programs. The numerical control system efficiently controls a machine tool having a number of spindles and automatic tool changer controllers.

Abstract: A control system for a physical plant has a state output detector for detecting operating conditions of the physical plant. A trajectory production unit produces desired operating conditions of the physical plant, and an error production unit produces error signals based on the detected operating conditions and the desired operating conditions. A control signal generator generates a control signal based on the detected operating conditions, the error signals, a control signal generated a predetermined time period ago, an error dynamics adjustment signal, and a control input signal. The control signal generator includes a control input signal generator and an error dynamics signal generator. The control input signal generator generates the control input signal based on a predetermined control relationship. The error dynamics adjustment signal generator generates the error dynamics adjustment signal and the predetermined time period based on a plurality of predetermined error dynamics relationships.

Abstract: Disclosed is an NC data creation method for creating NC data by designating a cutting amount to be cut by a single cutting operation carried out by a cutting tool, and a target cutting amount of a workpiece when a cutting operation program is created by an interactive mode, to thereby set a final cutting amount to an optimum value. The NC data is created in such a manner that a lower limit value is set with respect to a cutting amount to be cut by a single cutting operation carried out by the cutting tool, a required number of cutting operations and a final cutting amount are calculated based on the cutting amount and a target cutting amount, and the NC data is created by changing the NC data to a value in which each cutting amount is not smaller than the above lower limit value.

Abstract: A machine tool for performing drilling operations at a high speed on a rotating workpiece and for subsequently performing threading operations while minimizing loss time due to speed changes, based upon synchronization of the workpiece with tools that separately perform the drilling and threading operations. During the performance of the drilling operation, a high speed rotation of the workpiece is maintained and workpiece position is detected. The tapping tool is rotated to a similar high speed and is synchronized with the rotating workpiece in both rotational velocity and position. Upon completion of the drilling operation, tapping is performed and subsequent drilling operations may be resumed promptly. Since synchronization has been achieved, the switching between drilling and tapping operations may be obtained with little loss time.

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 robot route interpolation method for interpolation a polygonal route of a robot which is defined by the predetermined three or more points, wherein the acceleration at the time when a first velocity on the above polygonal route before a turning point is changed into a second velocity on the above polygonal route after the turning point is obtained based on the above first and second velocities so that, based on the above first velocity and the above acceleration, the above robot is moved toward the turning point at an uniform velocity of the first velocity and is also moved at an uniform acceleration in the direction of the above acceleration.

Abstract: A noncontact tracing control system for tracing machining a workpiece through a tracing of the contour of a model without contact. Coordinate values of a plurality of points on the model surface are acquired from measured values obtained by a plurality of times of sampling from two noncontact distance detectors (5a, 5b) provided at a tracer head of a tracing machine (3). A noncontact tracing control system (1) selects three points forming a triangle closest to an equilateral triangle, from among these points. A normal vector is acquired using the coordinate values of the vertices of these three points and outputs a command (SC) for rotating the tracer head (4) in the direction of a projection of this normal vector onto the X-Y plane. This command (SC) passes a D/A converter (17c), is amplified at an amplifier (18c), drives a motor (32c) and rotates the tracer head (4).

Abstract: In the invention, shapes of an insertion head, a jig and components are indicated to enable updating and new registration, and the relative position between the components and the mounter and the mounting process, the mounting sequence and the collision state of each component are indicated. Thereby input of data is facilitated and error of the data can be easily found. Data required at indicating the collision state indication and the name of the mounter to mount the component and the mounting direction, need not be stored by the user.

Abstract: A main CPU unit and a plurality of CNC units provided on a one-to-one correspondence with machine tools, and the main CPU unit is connected with an external storage device and an input device. To modify the mode of machine tool control or machining data of work, a new system program is down-loaded through the RAM of the main CPU unit into the CPU for the CNC unit, and according to this new system program, the part program including machining data normally stored in the CPU for the CNC unit.

Abstract: A servo system moving a transducer between tracks in a sector servo disk drive generates a velocity profile representing the variation of the desired velocity of the head in moving from a first track to a second track. The velocity profile has an acceleration phase and deceleration phase, with the transition from acceleration phase to deceleration phase identified as a switch point.The velocity of movement of the head is periodically sampled from the sector servo pattern in a sequence of sample periods during movement of the head. The energization of the head moving element is controlled so that the switch point occurs during one of the sample periods, thereby resulting in improved performance in positioning the head at the desired track. The system accommodates itself to variations, such as mechanical or electrical disturbances, which would otherwise affect the system.

Abstract: A numerical control system for controlling a machine tool including a control device for controlling the machine tool; external portable storage device for storing data; a disabling device for disabling device for disabling the control device; a read/write device, operable when the external portable storage device is manually coupled thereto, for reading data from the external portable storage device and for writing data to the external portable storage device; and a determining device for determining whether the external portable storage device is coupled to the read/write device. The disabling device disables the control device when the determining device determines that the external portable storage devices not coupled to the read/write device.

Abstract: A non-contact tracing control apparatus is disclosed which traces the surface of a model by using at least two optical distance detectors for detecting the distances therefrom to the model. When a first light corresponding to a first of the optical distance detectors is detecting a distance, a second light of another, second optical distance detector is either dimmed or shut off. Interference between more than one light reflected from the model and errors from, i.e., the first light reflected from the model incident on a second position sensor of the second optical distance detector can be avoided. The distances to a plurality of measurement points thus can be detected without interference even though the measurement points on the surface of the model are relatively close to one another.

Abstract: A tracing control system machines a workpiece through tracing by repeating a plurality of tracing passes in a tracing direction which is constant to a pick feed while detecting amounts of displacement of respective axes applied to a stylus. A first abrupt change region (P1c) on a model (1) surface is detected using the amounts of displacement of the respective axes obtained in the previous tracing pass, and a first position (X1c, Y1c) of the first abrupt change region in the X-Y plane is stored. Similarly, a second abrupt change region (P2c) is detected and a second position (X2c, Y2c) in the X-Y plane is stored. The tracing speed is lowered in the next tracing pass in the section within the range of each predetermined distance (l1, l2) in front of and behind an intersection (X3p, Y3p) with an extended line passing through the first position (X1c, Y1c) and the second position (X2c, Y2c).