Abstract: A controller that eliminates an error caused by acceleration/deceleration control, and controls the velocity of drive axes which is not represented by a rectangular coordinate system such that maximum allowable values of velocity, acceleration, and jerk of the drive axes are not exceeded. A program is analyzed in a command analysis section, and an interpolated position on a motion path in the rectangular coordinate system is determined in a first interpolation section, and then converted by means of a transformation section into drive axes' positions not in the rectangular coordinate system. In a tangential acceleration calculating section, a tangential acceleration is determined. In a velocity limit calculating section, a velocity limit at the time of each position being reached is determined which does not exceed maximum allowable values of velocity, acceleration, and jerk of the drive axes.

Abstract: An acceleration and deceleration control in which, for a relation between speed and acceleration, the low speed part need not be symmetrical with the high speed part, is performed such that an actual acceleration curve may lie along a restricted acceleration curve as much as possible. A curve representing actual acceleration-speed, corresponding to time-speed transition to be planned, approaches a restricted acceleration curve. When supplying a movement command which has been subjected to acceleration and deceleration processing to a servo control section, acceleration in the acceleration and deceleration processing is determined such that a speed-acceleration curve of the movement command which has been subjected to acceleration and deceleration processing may lie along predetermined speed-acceleration curve. The speed-acceleration curve is set for each axis and dependent on acceleration or deceleration, using parameters.

Abstract: A machine has a tool head which rotates on a C-axis (about the Z-axis) and an A-axis (about the X-axis). A tool length vector is multiplied by a matrix whereby a misalignment component ?s-H and the incline error (?s-H, ?s-H, ?s-H) of a spindle are corrected so that the tool length vector due to the misalignment of the spindle is obtained. The vector thus obtained is further multiplied by a transformation matrix that includes a rotation instruction ? for the A-axis and misalignments of the A-axis ?a-H (?a-H, ?a-H, ?a-H) to correct the misalignment of the A-axis so that the tool length vector as found when the A-axis has rotated by an equivalent of instruction ? is determined.

Abstract: The shapes of machine parts for which the possibility of interference exists are defined as rectangular parallelepipeds and it is judged whether or not there is interference between a first rectangular parallelepiped of a first machine part and a second rectangular parallelepiped of a second machine part. The method involves rotating the first rectangular parallelepiped and second rectangular parallelepiped so that each side of the first rectangular parallelepiped lies parallel to each axis of the reference coordinate system. Interference is thus judged based on whether any vertex of the second rectangular parallelepiped exists within the first rectangular parallelepiped. Likewise, interference is judged depending on whether any vertex of the first rectangular parallelepiped exists within the second rectangular parallelepiped.

Abstract: A controller that eliminates an error caused by acceleration/deceleration control, and controls the velocity of drive axes which is not represented by a rectangular coordinate system such that maximum allowable values of velocity, acceleration, and jerk of the drive axes are not exceeded. A program is analyzed in a command analysis section, and an interpolated position on a motion path in the rectangular coordinate system is determined in a first interpolation section, and then converted by means of a transformation section into drive axes' positions not in the rectangular coordinate system. In a tangential acceleration calculating section, a tangential acceleration is determined. In a velocity limit calculating section, a velocity limit at the time of each position being reached is determined which does not exceed maximum allowable values of velocity, acceleration, and jerk of the drive axes.

Abstract: A curve interpolation method capable of obtaining a curve approximating an original curve based on a sequence of command points within a tolerance set for the original curve, and performing interpolation on the obtained curve. Points Q1, . . . , Q2n are interpolated between respective two adjacent command points (P0, P1), (P1, P2), . . . , (Pn−1, Pn) as shape-defining points. The shape-defining points are positioned within a tolerance width 2w set to the original curve. One shape-defining point and shape-defining points surrounding the one shape-defining point are successively selected and an approximate curve for the selected shape-defining points is successively created. The one shape-defining point is moved towards the approximate curve to determine a modified shape-defining point for the one shape-defining point. A smooth curve passing a sequence of the modified shape-defining points is created and interpolation for machining is performed on the created curve.

Abstract: A numerical controller capable of precisely controlling a machine tool having an axis for turning a table with a simple machining program and easily coping with variation of a tool length. A machining path is commanded in a workpiece coordinate system turning with a table. The commanded machining path for linear-motion axes is interpolated based on a commanded machining velocity, to obtain interpolated positions on the machining path. Also, the commanded motions for rotational-motion axes are interpolated to obtain interpolated positions for the rotational-motion axes. The interpolated position for the linear-motion axes is corrected based on the interpolated position of the rotational-motion axes. The servomotors for the linear-motion axes are driven based on the corrected interpolated positions and the servomotors for the rotational-motion axes are driven based on the interpolated positions of the rotational-motion axes.

Abstract: A curve interpolation method capable of obtaining a curve approximating an original curve based on a sequence of command points within a tolerance set for the original curve, and performing interpolation on the obtained curve. Points Q1, . . . , Q2n are interpolated between respective two adjacent command points (P0, P1), (P1, P2), . . . , (Pn−1, Pn) as shape-defining points. The shape-defining points are positioned within a tolerance width 2w set to the original curve. One shape-defining point and shape-defining points surrounding the one shape-defining point are successively selected and an approximate curve for the selected shape-defining points is successively created. The one shape-defining point is moved towards the approximate curve to determine a modified shape-defining point for the one shape-defining point. A smooth curve passing a sequence of the modified shape-defining points is created and interpolation for machining is performed on the created curve.

Abstract: A numerical controller capable of precisely controlling a machine tool having an axis for turning a table with a simple machining program and easily coping with variation of a tool length. A machining path is commanded in a workpiece coordinate system turning with a table. The commanded machining path for linear-motion axes is interpolated based on a commanded machining velocity, to obtain interpolated positions on the machining path. Also, the commanded motions for rotational-motion axes are interpolated to obtain interpolated positions for the rotational-motion axes. The interpolated position for the linear-motion axes is corrected based on the interpolated position of the rotational-motion axes. The servomotors for the linear-motion axes are driven based on the corrected interpolated positions and the servomotors for the rotational-motion axes are driven based on the interpolated positions of the rotational-motion axes.

Abstract: A controller for a machine capable of performing acceleration/deceleration control to which an optimal tangential acceleration within an allowable maximum acceleration for each axis is applied. A first interpolation section receives data obtained by analysis of a program by a command analysis section, an makes interpolating calculation in every first sampling period to output it into an intermediate memory. A tangential acceleration calculating section determines a tangential acceleration based on each segment and the allowable maximum acceleration for each axis to output it into the intermediate memory. A deceleration target velocity calculating section prepares an acceleration/deceleration pattern for a plurality of segments stored in the intermediate memory, to output it to the intermediate memory.

Abstract: A controller to smoothly change speed of a machining tool to improve machining accuracy and speed of a machine. The controller includes a command analyzing section included in a block structure of software that analyzes a command program and converts it to data appropriate for use in a primary interpolation section. The primary interpolation section performs interpolation calculation in each first sampling period to obtain an interpolation point on a commanded path, and outputs the obtained interpolation point to an intermediate memory. The intermediate memory stores a motion amount for each axis, a feed rate and a block length. An acceleration/deceleration control section performs acceleration/deceleration control based on the data stored in the intermediate memory, and calculates speed in each second sampling period which is shorter than the first sampling period, to output the calculated speed to a secondary interpolation section.

Abstract: An acceleration and deceleration control in which, for a relation between speed and acceleration, the low speed part need not be symmetrical with the high speed part, is performed such that an actual acceleration curve may lie along a restricted acceleration curve as much as possible. A curve representing actual acceleration-speed, corresponding to time-speed transition to be planned, approaches a restricted acceleration curve. When supplying a movement command which has been subjected to acceleration and deceleration processing to a servo control section, acceleration in the acceleration and deceleration processing is determined such that a speed-acceleration curve of the movement command which has been subjected to acceleration and deceleration processing may lie along predetermined speed-acceleration curve. The speed-acceleration curve is set for each axis and dependent on acceleration or deceleration, using parameters.

Abstract: A moving path for which an interpolation instruction is given is a free curve expressed by a vector P(k). This curve is divided at predetermined cycles, and tangential vectors P' (k.sub.1) and P' (k.sub.2) at the start point and end point of each divided block are calculated. From these data and an instructed velocity F, an acceleration vector in the corresponding block is calculated. If each axial component of the calculated acceleration vector exceeds an acceleration limiting value set for each axis in advance, the instructed velocity F for the block is lowered to a value at which the axial component does not exceed the acceleration limiting value.

Abstract: A free-form curve interpolation method and device is provided for smoothly interconnecting curves using a non-uniform rational B-spline (NURBS) curve representation. This ability to interconnect free-form curves is important when machine parts of small dimensions or complex configuration. This is accomplished by a preprocessing calculation unit reads NC programs including an interpolation command of a NURBS curve expressed by a function using a parameter t as a variable, and calculates a distance .DELTA.L to move during an interpolation period T. A parameter change calculation unit calculates a change .DELTA.t in the parameter t brought on when moving by the distance .DELTA.L, on the basis of a current position specified by a current value t.sub.i of the parameter t. A movement amount calculation unit calculates a position when the value of parameter t is t.sub.i +.DELTA.t, by a defining formula of the NURBS curve.

Abstract: A three-dimensional cutter compensation system provides cutter compensation for machining a workpiece with a cutter having a round edge and an axis which is tiltable in any optional direction in three-dimensional space. The three-dimensional cutter compensation system includes a cutter direction vector calculating unit for calculating a cutter direction vector from present position control axes. The control axes control the tilt of the cutter. A cutter offset memory stores a radius of the cutter and a radius of an arc of the edge of the cutter while a programmed path calculating unit calculates a programmed path commanded by a machining program. A cutter compensation vector calculating unit calculates a cutter compensation vector from the cutter direction vector, the radius of the cutter and the radius of the arc of the edge of the cutter, and the programmed path. The cutter is then shifted in response to the cutter compensation vector.

Abstract: A speed control method for a numerical control apparatus of a machine tool which includes a rotational axis or axes changing a tool angle relative to a workpiece. The method obtains a distributive shift amount of each rotational axis, at every predetermined period, on the basis of positional data of each rotational axis with respect to start and end points of a shift command and a commanded shift speed; obtains, at every predetermined period, a positional deviation of a tip of the machine tool in a direction of each linear shift axis with reference to the rotational axis, based on a difference between a rotational position of the rotational axis in a next cycle and a rotational position of the rotational axis in a present cycle; for each linear shift axis, adds the positional deviation to the corresponding distributive shift amount, and outputs a resultant value as a corrected distributive shift amount for each linear shift axis; and for each rotational axis, outputs the obtained distributive shift amount.

Abstract: Disclosed is a method of screwing a pipe having threads with a different pitch on the outside and inside thereof into an object and assembling the same thereto by using a CNC machine tool. A male thread provided to a spindle is moved to an initial point I and point R by a quick traverse and then moved downward from the point R at a given speed and RPM. More specifically, a pipe is screwed into the object in accordance with the pitch of the thread on the outside thereof and assembled to a female thread of the object. When the male thread reaches a point Z and the pipe is assembled to the female thread of the object, the male thread is moved upward to the point R at a given speed and RPM. More specifically, the male thread is relieved from the pipe in accordance with the pitch of the thread on the inside of the pipe. Only the male thread is moved upward by the movement thereof to enable the pipe to remain engaged with the female thread, whereby the assembly of the pipe to the object is completed.

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 computerized numerical control apparatus for switching an acceleration constant for acceleration/deceleration prior to interpolation in accordance with the kind of an axis, in which an acceleration/deceleration prior to interpolation unit subjects a feed speed to an acceleration/deceleration process based on an acceleration constant designated by an acceleration constant switching unit. The feed speed subjected to the acceleration/deceleration process is transferred to an interpolation unit. The interpolation unit determines distribution pulses X.sub.p, Y.sub.p, Z.sub.p based on the speed data and movement data thereof. The distribution pulses are applied to an X-axis control unit and the like, respectively, and output to the respective axis motors M.sub.x and the like to execute the drive control thereof.

Abstract: A pitch error compensating system compensates for a pitch error of a ball screw of a numerically controlled machine tool. A pitch error calculating means (4) reads a present value from a present value register (3), reads pitch error corrective quantities (.epsilon.n, .epsilon.pn) in a corresponding period, and outputs pitch error corrective quantities as pitch error corrective pulses (CP) at equal intervals in the period. The pitch error corrective pulses (CP) are added to interpolated pulses (CP) by an adder (5). Since the pitch error corrective quantities are not outputted all at once, the machine tool moves smoothly, and the quality of the machined surface of the workpiece is improved.