With "feed-rate" Control Patents (Class 318/571)
  • Patent number: 5239247
    Abstract: A machine control permits the selection of input values defining configurations of motors on the machine in desired master-slave relationships. Individual master-slave dependencies may be selectively activated and deactivated. In response to a new commanded velocity for a master motor the control is effective to alter the velocities of all motors dependent therefrom as a function of change of velocity of the master motor and selectable slave ratios.
    Type: Grant
    Filed: June 17, 1992
    Date of Patent: August 24, 1993
    Assignee: Cincinnati Milacron
    Inventors: Thomas F. Habig, Ronald M. Sparer
  • Patent number: 5237251
    Abstract: A control unit enables tapping onto an end surface of a workpiece while rotating the workpiece. A workpiece rotational speed command (Vc) is applied from an NC unit (90) to first and second speed control circuits (111, 121) of first and second control circuits (110, 120), to operate these control circuits in a speed control mode, so that the workpiece (70) and a tapper (80) respectively mounted on first and second main spindles (10, 20) are caused to rotate at the same speed by first and second main spindle motors (11, 21).
    Type: Grant
    Filed: February 4, 1992
    Date of Patent: August 17, 1993
    Assignee: Franc Ltd.
    Inventors: Shinichi Kono, Hironobu Takahashi
  • Patent number: 5233535
    Abstract: In a control method and device for tapping, the phase difference between the spindle and the feed shaft at suspended positions is made equal to zero by controlling the rotation of the spindle of the feed of the feed shaft in a manner to minimize the damage on the machined portion and the rotation of the spindle and feed on the feed shaft are subsequently synchronized to reset them to their starting positions, thereby enabling an automatic reset operation.
    Type: Grant
    Filed: March 30, 1990
    Date of Patent: August 3, 1993
    Assignee: Kabushiki Kaisha Okuma Tekkosho
    Inventors: Norio Ito, Masato Ryoki
  • Patent number: 5229698
    Abstract: A method and apparatus for machine member motion control are provided which reduce position path errors in sampled data motion control systems. Position commands defining locations of a moveable machine member are periodically produced at a predetermined interval as is conventional in sampled data motion control. Intermediate position commands are produced at a predetermined sub-interval less than the predetermined interval in response to a parametric function relating member position and time, the parametric function being continuous through positions defined by the position commands. The intermediate position coordinates are computed as the sum of products of coefficients and coordinates of selected member position commands. To reduce processing time, the coefficients are computed and stored in advance of execution of motion for recall as motion progresses.
    Type: Grant
    Filed: August 6, 1990
    Date of Patent: July 20, 1993
    Assignee: Cincinnati Milacron Inc.
    Inventors: Thomas Minnich, Alfred H. Morser
  • Patent number: 5223777
    Abstract: A numerical controller accepts an instruction for the cutting of pockets with perimeters of irregular shapes, the instruction defining the perimeter by a series of vertex points and a straight-line, circular, or some other interpolation to move between these vertices. The numerical controller cuts the perimeter of the pocket by reference to the vertex points and constructs a bit map indicating the cut and uncut material after completion of the perimeter. A rule-based path generator employs the bit map to complete the interior of the pocket without explicit programming of those interior tool motions. The bit map is constructed on a real-time basis by offsetting the tool motion coordinates to roll over in the bit map space regardless of the tool starting position.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: June 29, 1993
    Assignee: Allen-Bradley Company, Inc.
    Inventors: Timothy W. Werner, Subbian Govindaraj, Timothy Bielawski, William C. Schwarz, Paul S. Kramer
  • Patent number: 5210697
    Abstract: A numerically controlled feeding apparatus having at least two linear feeding devices having intersected feeding directions includes a memory for storing beforehand representative correction vectors for representative instruction values indicating a predetermined number of reference feeding positions in the feeding space, each representative correction vector having information on deviation amount and deviation direction between a reference feeding position indicated by each of the representative instruction values and a real feeding position corresponding to each of the representative instruction value, a correcting unit for calculating a correction vector for an instruction value indicating any desired feeding position on the basis of a correction vector group of representative correction vectors for representative instruction values indicating plural feeding positions located in the neighborhood of the desired feeding position, and the instruction value indicating the desired feeding position, thereby to o
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: May 11, 1993
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Tasuku Kawanabe
  • Patent number: 5206813
    Abstract: When a position of a tool blade tip for displaying the work shape, tool shape and tool locus is calculated by an interpolation arithmetic operation based on the interpolation instruction and feed speed instruction within a numerical control data, the calculated position of the tool blade tip is compared with the display scope every time an interpolation arithmetic operation is conducted; a determination is made as to whether or not the tool shape and tool locus to be displayed are inside of the display scope, and when they exist outside, uses a higher speed as the feed speed for the interpolation arithmetic operation. Therefore, even when an operator tries to check numerical control data by reducing the display scope for local graphic display, the interpolation outside the display scope can be conducted at a higher speed to thereby allow the operator to check the numerical control data quickly and immediately.
    Type: Grant
    Filed: November 21, 1991
    Date of Patent: April 27, 1993
    Assignee: Kabushiki Kaisha Okuma Tekkosho
    Inventors: Yukinori Otsubo, Tomohiro Suzuki, Yasushi Fukaya
  • Patent number: 5204599
    Abstract: When the movement of a machine element is guided by a multi-axial, numerically controlled machine through the selection of interpolation points which are calculated and stored off-line, a tool-radius correction is rendered possible. This occurs because correction interpolation points are calculated on the basis of interpolation points and thus, with the least possible expenditure of time, a new trajectory curve can be generated, with which the radius changes are considered. In addition, a change in feedrate can be achieved through the selection of override values by placing fine interpolation points between two interpolation points at a time.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: April 20, 1993
    Assignee: Siemens Aktiengesellschaft
    Inventor: Georg Hohn
  • Patent number: 5200680
    Abstract: A feed speed control method for a numerical control device in which a feed speed of a tool traveling along an instructed machining path is controlled in accordance with a machining program. The speed of each axis is derived (S2), and the acceleration of each axis is derived from a speed variation between adjacent blocks (S3). When the acceleration (.DELTA.Vx) is larger than a permissible acceleration (.DELTA.Vxmax) (S4), first ratios (K1) of the permissible accelerations to the accelerations are derived for individual axes (S5), and the smallest of the first ratios is selected. The command speed is multiplied by the square root of the smallest first ratio to derive an actual feed speed (S9). In this way, shock to a machine is reduced and an excessive load on a servomotor is reduced even when blocks continue for successive infinitesimal distribution distances, as in the case wherein a curve is approximated by the use of straight lines.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: April 6, 1993
    Assignee: Fanuc Ltd.
    Inventors: Takao Sasaki, Kentaro Fujibayashi, Toshiaki Otsuki, Yasuhiro Saito
  • Patent number: 5198984
    Abstract: A numerical control method controls a machining path of a tool. A second feed speed data is determined which causes a machining path error that is N times as large as a prescribed first path error when the machining path of the tool is driven according to an instructed first machining path data. An actual machining path of the tool is predicted according to the first machining path data and the second feed speed data. A second path error data is determined according to a difference between the predicted machining path and the first machining path data. A positional correction data is obtained by subtracting the first path error data from the second path error data. Then, second machining path data is calculated by adjusting the first machining path data by an amount corresponding to the positional correction data. A machine tool is driven according to the second machining path data and the second feed speed data.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: March 30, 1993
    Assignee: Okuma Corporation
    Inventors: Takahiro Yamaguchi, Kenji Ito
  • Patent number: 5184053
    Abstract: A control device for a tool driving unit is disclosed wherein a tool such as a tap or a drill is controlled to be rotated and axially moved by the control device. The tool driving unit has a spindle servo motor adapted to be driven according to a spindle current command and a feed shaft servo motor adapted to be driven according to a feed shaft current command which are provided by a single microcomputer which operates as the control device. The microcomputer reads an NC program and outputs a spindle command for the spindle servo motor when performing tapping, and outputs both the spindle command and a first feed shaft command for the feed shaft servo motor when performing drilling. A thread pitch changing controller for controlling a thread pitch outputs a second feed shaft command for the feed shaft servo motor when performing tapping.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: February 2, 1993
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Satoshi Maruo, Chikamasa Hattori, Fumio Kameyama
  • Patent number: 5180957
    Abstract: A tracing control system for machining a workpiece through tracing by calculating speed command values of respective axes, using change amounts detected by a tracer head, and moving a cutter relative to the workpiece through control of the speed of the respective axes in accordance with the speed command values. The system is provided with calculating means for calculating predetermined values in proportion to amounts of change in the speed command values of the respective axes, and a U-axis motor and a W-axis motor for moving only a model in parallel with the above respective axes by amounts corresponding to the respective predetermined values. A sub-table, on which only the model is placed is provided on a main table of a tracing machine tool, is moved in the same direction as the direction of movement of the main table, by an amount proportional to the amounts of change in the speed command values, for example, the amounts of delay in the reactions of the servo systems.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: January 19, 1993
    Assignee: Fanuc Ltd.
    Inventors: Hitoshi Matsuura, Hitoshi Aramaki
  • Patent number: 5177421
    Abstract: A method of correcting a change of position of a machine tool having at least two control axes avoids abrupt machining errors. A position correction means (12) outputs correction pulses (Xcp, Ycp) so that the ratio of actual amounts of movement of the respective axes, obtained from the output values of position detectors (8X, 8Y) detecting a position of the machine tool, becomes equal to the ratio (R1) of distribution pulses (Xp1, Yp1) for the respective axes. The correction pulses (Xcp, Ycp) are added to the distribution pulses (Xp1, Yp1). Accordingly, an abrupt machining error caused at the beginning or just before the end of machining, or when machining a corner of a workpiece, is alleviated.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: January 5, 1993
    Assignee: Fanuc Ltd.
    Inventors: Takao Sasaki, Kentaro Fujibayashi, Makoto Haga
  • Patent number: 5177420
    Abstract: A control program for controlling an object such as a machine tool, a robot, or the like is composed of an actuator program, a step program, and a logic program. The actuator program defines the input-output relationship of each actuator of the object based on a basic operation pattern. The step program defines the step-wise operation of said actuator. The logic program defines logic conditions such as an interlock condition.
    Type: Grant
    Filed: April 30, 1990
    Date of Patent: January 5, 1993
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Hiroaki Wada, Kunikazu Negishi
  • Patent number: 5172040
    Abstract: Disclosed is a numerical control apparatus for controlling a chopping operation of a tool used in a grinding machine and the like. A programmed instruction value calculation circuit (2) outputs an upper dead point instruction (Zu) and a lower dead point instruction (Zl), a correction value calculation circuit (3) calculates and outputs correction values (.DELTA.Zu, .DELTA.Zl), and a chopping instruction calculation circuit (4) outputs a chopping control output to a manual control circuit (6) based on these instructions and correction values to operate a servo motor. When an instruction value (Zi) is input from a manual pulse generator (5) to the chopping instruction calculation circuit (4), the chopping is effected while continuously changing the upper and lower dead points, thereby enabling an operator to easily adjust the upper and lower dead points.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: December 15, 1992
    Assignee: Fanuc Ltd
    Inventors: Takao Sasaki, Kentaro Fujibayashi, Haruhiko Kozai
  • Patent number: 5163171
    Abstract: When an NC data output format is to be set, the NC data output format is expressed using characters or symbols, the NC data output format is entered from an operators's panel (19) using the characters or symbols, the characters or symbols of the entered NC data output format are converted into internal codes and the NC data output format is set in a RAM (14). When the NC data output format is to be revised, the NC data output format stored in the RAM (14) is converted from the internal codes to characters or symbols and displayed on a display unit (16), a location to be revised is designated and the location is revised by characters or symbols, and the revised NC data output format is converted into internal codes.
    Type: Grant
    Filed: January 4, 1990
    Date of Patent: November 10, 1992
    Assignee: Fanuc Ltd.
    Inventors: Masaki Seki, Takashi Takegahara, Toru Matsunaka
  • Patent number: 5159250
    Abstract: A robot control method utilizing a convolution in which a calculating method is simple. Simultaneously, a synchronous operation of a multi-shaft system, such as a computerized numerical control machine tool or robot, is made easy by convolving an input displacement quantity to a previously defined torque locus. The method comprises a first step of seeking a filter characteristic function most suitable for the control system, a second step of storing the filter characteristic function obtained at said first step for producing an input signal with respect to a displacement quantity desired to drive the robot, a fourth step of convolving the filter characteristic function and the input signal with respect to the displacement quantity obtained at the first step and third step, a fifth step for seeking the position locus by integrating the speed locus obtained at the fourth step, and sixth step for driving the robot in response to the speed locus and the position locus obtained at the fourth step and fifth step.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: October 27, 1992
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Byeong-Hwan Jeon, Sung-Kwon Kim
  • Patent number: 5155425
    Abstract: An NC data execution method which permits an efficient checking of the validity/invalidity of NC data through a simple operation. In an NC data execution process, a processor of an automatic programming apparatus reads out NC data, block by block, from a memory (S2), and determines whether or not the read NC data block satisfies an NC data execution interrupt condition, e.g., whether or not the data block contains a specific code (S3). When the interrupt condition is fulfilled, the data block is displayed at an input display field on the screen (S4), and then the NC data execution, including a graphic display operation based on the content of the data block satisfying the interrupt condition, e.g., a display of a tool path and the reading and display of the next block, is automatically interrupted, whereby the operator is allowed to thoroughly check the data block satisfying the interrupt condition.
    Type: Grant
    Filed: January 14, 1991
    Date of Patent: October 13, 1992
    Assignee: Fanuc Ltd.
    Inventors: Masaki Seki, Takashi Takegahara, Masatoshi Nakajima
  • Patent number: 5153490
    Abstract: In a machine tool having a table adapted to support a workpiece, a plurality of drive shafts for moving the table in three directional directions by servomotors, servo control apparatus controlling the servomotors in response to position instructions, drive shaft control apparatus including position detectors of the servomotors, each drive shaft control apparatus is made up of a servomotor rotation reversal detector for producing a movement reversal signal, a memory device for storing correction amounts necessary to compensate for a position error of the axis of the spindle of the machine tool which occurs as a result of reversal of the direction of movement of the drive shaft and other drive shafts and a transfer switches for selecting the memory device in response to the movement reversal signal and for feeding back to the servo control apparatus the correction amount read out from the memory device.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: October 6, 1992
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Toshihiro Ueta, Ikuo Kuribayashi, Masayuki Kato, Jun Fujita
  • Patent number: 5153491
    Abstract: A spindle motor control method capable of high-accuracy contour machining uses a vector control processor executing a speed loop process to obtain a torque command (Tc). Vector control is performed (S4, S7) in accordance with a magnetic flux command (.PHI.c) set at a predetermined fixed value (CF.PHI.) when a spindle motor is being driven in a contour control mode. This prevents irregularity in motor speed and motor vibration attributable to a delay of the actual magnetic flux of the spindle motor behind the magnetic flux command, thus enabling high-accuracy contour machining. In a normal speed control mode or an orientation mode for tool replacement, the vector control is effected (S4 to S6, S8) in accordance with the magnetic flux command (.PHI.c), which is obtained on the basis of the torque command (Tc), its maximum value (Tcmax), maximum magnetic flux command (.PHI.cmax) set in dependence on the rotating speed of the motor, and minimum magnetic flux (NR.PHI.cmin, OR.PHI.min).
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: October 6, 1992
    Assignee: Fanuc Ltd.
    Inventors: Yoshiki Fujioka, Hironobu Takahashi
  • Patent number: 5150025
    Abstract: A system for reloading pitch error correction data at the time of replacing a movable part constituting part of a mechanical system of a numerically controlled machine tool. A command to reload the pitch error correction data is preset in a machining program at the time of replacing the movable part. A numerical control device reads this command. If a parameter reload command is given (S1), and if it is the pitch error correction data (S2), it is determined whether the movable part is situated at the original position (S3), and the pitch error correction data is automatically reloaded (S4). Accordingly, the operator is not required to carry out any operation related to the reloading of the pitch error correction data, and thus the machining can be effected with the use of correct pitch error correction data.
    Type: Grant
    Filed: January 2, 1991
    Date of Patent: September 22, 1992
    Assignee: Fanuc Limited
    Inventors: Takao Sasaki, Kentaro Fujibayashi, Shintaro Kageyama
  • Patent number: 5144213
    Abstract: A gravity axis brake control method of controlling the brake of the gravity axis of a computerized numerical controlled machine tool, wherein a computerized numerical control (CNC) notifies a programmable controller (PC) that the control of the gravity axis will be interrupted (Step S1), the PC outputs a signal for actuating the brake at the machine tool (step S3), and the CNC turns off an exciting current of a servo motor after a preset brake operation completion time has passed (step S7). The preset time is longer than the time after that at which the CNC notifies the PC to interrupt the control of the servo motor as compared to the time at which the brake locks the gravity axis.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: September 1, 1992
    Assignee: Fanuc Ltd
    Inventors: Takao Sasaki, Kunihiko Murakami, Masahiko Hosokawa
  • Patent number: 5142210
    Abstract: An abnormal state detecting apparatus of a machine tool having a servomotor. The apparatus is provided with a device for detecting an abnormal acceleration and an abnormal torque of the servomotor and a device for detecting an abnormal operation state of the servomotor from the directions of the detected acceleration and torque. When the torque, acceleration and operation state are all abnormal, the machine tool is judged to be in an abnormal state and the servomotor is controlled, thereby protecting the machine tool from an impact in an abnormal operation state.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: August 25, 1992
    Assignee: Okuma Machinery Works Ltd.
    Inventors: Takayoshi Kojima, Satoshi Eguchi, Takayasu Asano
  • Patent number: 5140239
    Abstract: A non-contact tracer control device for carrying out a profile machining on a workpiece while tracing the profile of a model in a non-contact fashion. Two non-contact distance detectors (5a, 5b) are slantingly mounted to a tracer head 4) controlled through a rotary axis, and measurement values obtained by the two non-contact distance detectors (5a, 5b) are sampled at predetermined sampling intervals. Based on the measurement values obtained at previous and current sampling times, coordinates of the four vertexes of a very small rectangle on the surface of a model (6) are obtained, and a normal vector is obtained by using the coordinates of three required vertexes out of the four vertexes. The tracer head (4) is rotated in the direction of a projected vector obtained by projecting the normal vector onto an X-Y plane.
    Type: Grant
    Filed: March 18, 1991
    Date of Patent: August 18, 1992
    Assignee: Fanuc Ltd.
    Inventor: Hitoshi Matsuura
  • Patent number: 5140236
    Abstract: A spline interpolation method of subjecting given points to interpolation by using a cubic spline curve is provided. A first-derivative vector is derived from a preset number of points including a starting point (P.sub.1), and a cubic equation between the starting point and a next point is derived based on the coordinate values of the preset points including the starting point (P.sub.1) and the extreme point condition of the starting point (P.sub.1), to derive a spline curve between the starting point (P.sub.1) and a point (P.sub.2) next to the starting point (P.sub.1). Next, the first-derivative vector at P.sub.2 and a new next point are used instead of the starting point (P.sub.1), to derive a cubic curve between P.sub.2 and P.sub.3.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: August 18, 1992
    Assignee: Fanuc Ltd.
    Inventors: Hideaki Kawamura, Takao Sasaki, Toshiaki Otsuki
  • Patent number: 5134767
    Abstract: An automatic tool changing device in a machine tool for automatically changing a tool at an automatic tool changing (ATC) region. A spindle head is disposed reciprocally movable between a machining region and the ATC region by way of a machine origin which is positioned at a boundary point therebetween. The device includes a control device having a concurrent execution means in which deceleration control to the spindle head toward the machine origin and the acceleration control for the subsequent movement of the spindle head away from the machine origin are taken place in overlapping relation.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: August 4, 1992
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Shoki Yasuda
  • Patent number: 5136224
    Abstract: A digitizing method for digitizing model surface data by tracing a model (MDL) with a stylus (STL) is described. At the time of digitizing, a time (T) required for predetermined conditions to be satisfied and stylus traveling distance (.DELTA.L) during this time are monitored, tracing velocity (F) is obtained based on this time and traveling distance, and the tracing velocity is output along with data indicative of the model surface profile.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: August 4, 1992
    Assignee: Fanuc Ltd.
    Inventors: Hitoshi Matsuura, Hitoshi Aramaki
  • Patent number: 5132912
    Abstract: A numerical control method and an apparatus sets the feed rate at the time the first action ends as a tapping feed rate, and sets the spindle rate at the time the second action ends as a tapping spindle rate, and starts the third action after the first and second actions end simultaneously. In a tapping process where the spindle angle at the start position is set at a predetermined tapping start angle, the first action for setting the feed shaft position at the tapping start position and the second action for setting the spindle angle as the tapping start angle are executed simultaneously, and the third action is executed without changing the feed and spindle rates because the feed rate has already been set at the tapping feed rate and the spindle rate has already been set at the spindle tapping rate at the time when the first and second actions end.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: July 21, 1992
    Assignee: Kabushiki Kaisha Okuma Tekkusho
    Inventors: Kenji Ito, Masato Ryoki
  • Patent number: 5130625
    Abstract: This invention concerns a control unit for program-controlled machine tools with control circuits for the individual feed motors (20) of the moving machine parts (2) which are connected to the program control unit (34) and also contain at least one switching element (14) for manually switching on feed motors (20). In order to give the operator a feel for the respective operating process in manual operation, each control circuit according to this invention has at least one sensor (26, 42) for detecting a power parameter (I;M) of the respective feed motor (20). Furthermore, a brake gear (30 or 44) that is controlled by the output signals of the sensor (26; 42) is assigned to each switching element that is designed as a manually adjustable control element (14), whereby the braking device is actuated in proportion to the power parameters picked up by the sensors and it makes continued turning of the control element which is designed as a hand crank more difficult.
    Type: Grant
    Filed: November 9, 1990
    Date of Patent: July 14, 1992
    Assignee: MAHO Aktiengesellschaft
    Inventor: Werner Babel
  • Patent number: 5126645
    Abstract: A grinder robot having a grinder can be operated by both of a force control and a position control to grind a workpiece surface quickly and acccurately. When the grinder has not reached a target grinding point position to finish grindings, force loop drive control means are selected to drive the grinder in order to grind a work by a force control. After a grinding point ground by the grinder has reached the target position, then, position drive control means are selected to drive the grinder by a position control in order to execute precise grindings. A grinding amount in every grinding in a force control area is relatively large and a grinding speed in every grinding in a position control area is relatively fast. As a result, a workpiece can be ground quickly and accurately by the grinder robot.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: June 30, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takashi Yoshimi, Makoto Jinno
  • Patent number: 5122717
    Abstract: An apparatus for producing a numerical control program, which uses a unit motion pattern icon. A menu memory unit stores a menu of unit motion patterns corresponding to subdivided machine motions, a task memory unit for storing process programs for converting each unit motion pattern to each numerical control program; a display unit for displaying the menu of the unit motions; a task controller for reading the corresponding process program, outputting a parameter guidance corresponding to the unit motion pattern, and converting the unit motion to the corresponding numerical control program; and input unit for appointing a unit motion patterns and inputting a parameter; and NC program file for storing the numerical control program.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: June 16, 1992
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Akihiro Hayashi
  • Patent number: 5121041
    Abstract: A tracing control system for machining a workpiece through tracing by calculating speed commands of respective axes, using change amounts detected by a tracer head, and by moving a cutter relative to the workpiece through a control of the speed of the respective axes in accordance with the speed commands. First delay speed commands are obtained from the speed commands (Vx, Vz) at delay circuits (14a, 14c), respectively, and second delay speed commands are obtained at second delay circuits (14b, 14d), respectively, the differences between the first delay speed commands and the above second delay speed commands are calculated, and an X-axis main motor and a Z-axis main motor are driven in accordance with the first delay speed commands, and an X-axis sub-motor and a Z-axis sub-motor are driven in accordance with the calculated differences, thereby move the tracer head.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: June 9, 1992
    Assignee: Fanuc Ltd.
    Inventors: Hitoshi Matsuura, Hitoshi Aramaki
  • Patent number: 5119004
    Abstract: The invention relates to a reference-point return method for returning a movable element of a machine to a reference point using solely a linear scale, without relying upon a limit switch. The method includes providing the linear scale (1) with a second scale portion (2) for stipulating a deceleration starting position and a reference-point position, in addition to first scale portion (3, 4) for generating two-phase signals for position detection, generating signals (S.sub.1, S.sub.2) indicative of the deceleration starting position (D) and reference-point position (O) from the second scale portion (2) of the linear scale, slowing a reference point return rapid-traverse velocity (Va) to a reference-point return rapid-traverse velocity (Vb) using the deceleration starting signal (S.sub.1), and effecting return to the reference point by stopping movement in response to the reference-point signal (S.sub.2).
    Type: Grant
    Filed: March 23, 1990
    Date of Patent: June 2, 1992
    Assignee: Fanuc Ltd.
    Inventors: Keiji Sakamoto, Shigeyuki Ushiyama, Mitsuyuki Taniguchi, Hirofumi Kikuchi
  • Patent number: 5117169
    Abstract: A numerical control (NC) device 10 for a machine tool 1 provided with a measurement probe 2b effects measurements of a work 4 on the machine table 5 after a working process. A measurement program, generated by the NC device by modifying a working program, controls the relative movement of the probe 2b with respect to the workpiece 4 such that the probe 2b moves along the contour of the worked portion of the workpiece 4 with a displacement from the neutral position thereof, wherein the displacement of the probe is sampled at a predetermined sampling period. A working error calculation program 17 calculates the working error from the sampled displacements. If the working error is judged correctable, a outside tolerance range and correction re-working is effected so as to reduce the working error. The measurement/re-working cycles are repeated until the working error is within tolerance.
    Type: Grant
    Filed: December 4, 1990
    Date of Patent: May 26, 1992
    Assignees: Yoshiaki Kakino, Yasuda Kogyo Kabushiki Kaisha, Mitutoyo Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yoshiaki Kakino, Shigeaki Tokumo, Tetsuo Nakamura, Torao Takeshita
  • Patent number: 5117368
    Abstract: A tapping device generates a cycle suspension squence by which a tapping process can be temporarily suspended and a cycle restart sequence by which the suspended tapping process can be restarted, thereby securing a safe operation at the time of an abnormality in the tapper or at trial cutting. Tapping wherein tapping is controlled by synchronizing the rotation of a spindle and the feed on a feed shaft. The device includes a sequence generating section which generates a tapping sequence for execution of said the tapping process, a cycle suspension sequence which slows down and suspends in synchronism the rotation of the spindle and the feed on said feed shaft to sumit detachment of the tapper from the work, and a cycle restart sequence which resumes the tapping process. A memory is provided which stores the detected oriented angle of the spindle for the start of cutting in the tapping sequence.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: May 26, 1992
    Assignee: Kabushiki Kaisha Okuma Tekkosho
    Inventors: Takahiro Yamaguchi, Takahiko Kitade
  • Patent number: 5103150
    Abstract: An involute interpolation error correction system for correcting an error attributable to an involute interpolation of a numerical control device or the like. When machining is effected in accordance with a command for an involute curve (In1), a bite is produced in an actual work shape in the vicinity of a basic circle (C). The start point (Ps3) of this bite, the radius (Rs) from the basic circle (C) and an error amount (De) in the normal direction of the bite are obtained from the work shape, and this data is set as parameters in the numerical control device. The numerical control device allows a cutting along the involute curve (In1) up to the point Ps3, and then cuts along an involute curve (In3) having an end point which is deviated from the point Ps3 by the error amount (De) in the normal direction, whereby a bite-free involute curve machining can be effected.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: April 7, 1992
    Assignee: Fanuc Ltd.
    Inventors: Takao Sasaki, Toshiaki Otsuki, Kunihiko Murakami, Masafumi Sano
  • Patent number: 5101146
    Abstract: A device for correcting mechanical errors in an NC machine, by which an incremental amount of movement of a control shaft is corrected for mechanical errors such as backlash and lost motion and the value thus corrected is transmitted to a servo control section. The incremental amount of movement of the control shaft calculated every sampling is subjected to a speed adjustment. A position command value is calculated by progressively adding a command value of the incremental amount of movement subjected to a speed adjustment. A position command correction value is obtained by adding a predetermined amount of correction for mechanical error to the position command value. A corrected incremental amount of movement is calculated by substracting a previously calculated position command correction value, and is transmitted to the servo control section.
    Type: Grant
    Filed: August 7, 1990
    Date of Patent: March 31, 1992
    Assignee: Mitsubishi Denki K.K.
    Inventor: Takeo Teshima
  • Patent number: 5089758
    Abstract: A direct-drive robot is controlled by a process in which a digital positional deviation value (between a command value and a value delivered from an encoder for detecting the motion of a movable part to be controlled in the robot) is increased or decreased in accordance with a result of comparison of the digital positional deviation value with a threshold value before the digital positional deviation value is converted to an analog value, and the analog value is then amplified by a gain depending upon the result of the comparison of the digital positional deviation with the threshold value. This enhances the servo rigidity, restrains slight vibrations during a stopping operation of the robot, and achieves smooth operation during a moving operation of the robot.
    Type: Grant
    Filed: July 5, 1990
    Date of Patent: February 18, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kenji Sogawa
  • Patent number: 5083070
    Abstract: A combination work supporting table and computer controlled robot wherein, preferably, a rotatable index table includes a concentric column having a computer controlled robot mounted upon the column outer end in spaced relationship to the table work supporting surface. A computerized robot controller controls both the robot and the rotation of the index table permitting an extensive range of robot movement over a large work area in a concise space.
    Type: Grant
    Filed: May 10, 1990
    Date of Patent: January 21, 1992
    Assignee: Accubilt, Inc.
    Inventors: Mark D. Poupard, Edward L. Cooper
  • Patent number: 5083280
    Abstract: The tool feed rate correcting method for numerical control system and the apparatus therefor according to this invention correct the feed override values using an override correction coefficient which is calculated from the displacement information of the tool and control the tool feed rate so that machining loads can be maintained within predetermined range irrespective of the machining conditions. This invention is therefore effective in realizing machining with a high efficiency as well as in reducing the cost.
    Type: Grant
    Filed: January 26, 1990
    Date of Patent: January 21, 1992
    Assignee: Kabushiki Kaisha Okuma Tekkosho
    Inventors: Kyoichi Yamamoto, Takao Hasebe
  • Patent number: 5083072
    Abstract: A position control apparatus and method for controlling a servo motor includes a D/A unit which converts speed command to analog signals, an up/down counter which increases and decreases pulse of encoder based on the rotating direction of a servo motor in either the x or y directions, and a timer periodically generating interrupt signal to a microprocessor. The position control apparatus and method that can control a servo motor by calculating simple linear equation without calculating complicated exponential function if the maximum speed of the servo motor and time required for the servo motor to reach its destination position is furnished to the control system.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: January 21, 1992
    Assignee: Samsung Electronics Co. Ltd.
    Inventor: Jin Il Song
  • Patent number: 5083074
    Abstract: In a method for performing a synchronized superposed operation of two servomotors, controllers for the servomotors perform the control for achieving the synchronized superposed operation by: calculating, for each of the servomotors, the difference, or differences, between the ideal speed and/or position deviations obtained from a control command and the actual speed and/or position deviations obtained from the rotation of the servomotor; calculating a speed correction quantity, or a speed correction quantity and a current correction quantity, from the discrepancy, or discrepancies, between the differences calculated for both of the servomotors; and adding the correction quantity, or quantities, to a speed command, or to a speed command and a current command, given to the subsidiary shaft side. Thus, a synchronized superposed operation of servomotors in which speeds and responses of the main shaft and the subsidiary shaft are well balanced therebetween can be achieved.
    Type: Grant
    Filed: August 22, 1990
    Date of Patent: January 21, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hironori Suzuki, Teruaki Ikutame
  • Patent number: 5081407
    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.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: January 14, 1992
    Assignee: Fanuc Ltd.
    Inventors: Shinichi Kono, Hironobu Takahashi
  • Patent number: 5077507
    Abstract: A servo control apparatus comprises an abnormality detection circuit which calculates a difference between the quantity of rotation of a servo motor from a reference point calculated on the basis of an accumulated value of the position feedback and the quantity of rotation of the servo motor from the reference point counted by a rotational detector, and puts out an absolute position abnormality signal when the calculated difference value exceeds a predetermined value.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: December 31, 1991
    Assignee: Mitsubishi Denki K.K.
    Inventors: Akira Mitani, Mitsuyasu Kachi
  • Patent number: 5059881
    Abstract: Backlash compensation for a numerical control apparatus. Backlash compensation is intelligently applied based on a judgment as to a change in direction or velocity commanded for a cutting tool, table, or the like. Backlash compensation data is stored into a memory of a numerical control apparatus. A judgement is made as to the necessity of backlash compensation, based on velocity data of the feed mechanism, and deciding whether the feed mechanism is being stopped or reversed. Compensation data is output to a servo drive unit.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: October 22, 1991
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Jun Fujita, Michio Matumoto
  • Patent number: 5055753
    Abstract: A computer winding control and operator display for winding complex coils is programmed to control stepper motors connected to an arbor and a coil filament laying head. The computer program generates a series of commands to move the arbor and the head. The commands specify acceleration, velocity, extent of movement, and deceleration. The program at certain program steps stops the motion and generates operator display messages.
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: October 8, 1991
    Assignee: Honeywell Inc.
    Inventors: Donald R. Hermanson, Steven A. Prokosch, Daniel M. Jenson
  • Patent number: 5055754
    Abstract: A detection apparatus is provided which is capable of detecting an excessive position error in a servo system in an appropriate manner over a wide servomotor rotational rate region, so as to accurately and immediately determine an overload state of a servomotor and the like. A permissible maximum value of the position error is obtained by first obtaining a product of a proportional coefficient set beforehand and a maximum value of pulse distribution amounts--a number of movement command pulses distributed from a central processing unit of a numerical control unit. The pulse distribution amounts are respectively stored in a table provided in a memory. The product is then, second, divided by a position loop gain. The central processing unit then determine that an excessive position error has occurred when an actual position error read from an axis controller is greater than or equal to the permissible maximum value.
    Type: Grant
    Filed: January 10, 1990
    Date of Patent: October 8, 1991
    Assignee: Fanuc Ltd.
    Inventors: Hajimu Kishi, Naoki Fujita, Haruyuki Ishikawa
  • Patent number: 5047702
    Abstract: During synchronous control, a first servo motor controls a position of a first spindle system and a second spindle system having a second servo motor makes calculations for estimating the torque required for the second servo motor and gives a command, so that, when a rotational phase difference between the two servo motors exceeds a predetermined value, the rotational phase difference is made equal to zero by a rotational phase difference signal. A torque command to the first servo motor, an inertia ratio between the first and second servo motors, the rotational resistance of the two spindle systems and so on are input to a torque estimator which makes calculations for estimating the torque required for the second servo motor. The estimated torque is used to control the second servo motor. The two servo motors thus generate the appropriate torque when a work held between the two spindle systems is processed. It is therefore possible to significantly reduce the torsional torque applied to the work.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: September 10, 1991
    Assignee: Kabushiki Kaisha Okuma Tekkosho
    Inventors: Yoshimaro Hanaki, Masayuki Nashiki
  • Patent number: 5043644
    Abstract: A method of correcting a machining program for a numerical control device during an execution of the program is provided. A created machining program, which is stored in a memory (5), is executed for a program check, a single block stop is effected at a portion (2) at which an error is found in the machining program, and the machining program is executed in reverse to a predetermined block (P1). Then the machining program is corrected and executed. Accordingly, it is not necessary to return to the beginning of the machining program for a reexecution thereof, and thus the machining program can be efficiently corrected.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: August 27, 1991
    Assignee: Fanuc Ltd.
    Inventors: Takao Sasaki, Toshiaki Otsuki, Ryouji Eguchi
  • Patent number: RE33910
    Abstract: A turning machine is characterized by a new and improved control and mechanism for positioning the turning tool on the head. A CNC control issues command signals for selectively positioning the tool on the head. These signals are developed from an encoder which provides the instantaneous position of the rotating part being turned and from a program in the CNC containing information about the part. A closed loop control system receives these command signals and converts same into a control current for a linear motor which is the prime mover controlling the positioning of the tool on the head. The linear motor operates a carriage on the head and the cutting tool mounts on the carriage opposite the connection of the linear motor to the carriage. The carriage is a hollow bar guided on the head by sets of rollers which are cooperatively arranged to provide yieldably forceful constraint of the bar.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: May 5, 1992
    Assignee: The Cross Company
    Inventor: Ronald E. Compton