ISO 230-4:2022 工作機械のテストコード—パート4：数値制御工作機械の循環テスト | ページ 5

3.1

nominal path

<circular interpolation> numerically controlled and programmed circular path defined by its diameter (or radius), the position of its centre and its orientation in the working zone of the machine tool and which may be either a full circle or a partial circle of at least 90°

Note 1 to entry: Linear interpolation (G01) or circular interpolation (G02 or G03) or other types of interpolation may be used to generate nominal circular path.

3.2

actual path

path produced by the machine tool when programmed to move on the nominal path (3.1)

3.3

bi-directional circular error

bi-directional circular deviation

G(b)

minimum radial separation of two concentric circles (minimum zone circles) enveloping two actual paths (3.2) ここで, one path is carried out by a clockwise contouring motion and the other one by an anticlockwise (counter-clockwise) contouring motion

Note 2 to entry: The bi-directional circular error G(b) can be evaluated as the maximum radial range of deviations around the least squares circle. The least squares circle is calculated from two paths, i.e. the clockwise and the anticlockwise (counter-clockwise) paths.

Note 3 to entry: Bi-directional circular error G(b) does not include set-up errors, i.e. centring errors of the measuring instrument.

Note 4 to entry: Bi-directional circular error G(b) measurement requires the use of test equipment only with calibrated displacement measurements (no need for calibrated length measurements for path diameter). The measurements of radial error F (3.5) and mean bi-directional radial error value D (3.6) require test equipment with both calibrated length and calibrated displacement (see Annex A).

Note 5 to entry: A line situated in a plane is said to be circular when all its points are contained between two concentric circles whose radial separation does not exceed a given value (see Figure 2).

Note 6 to entry: Designation G(b) is for measurements with external measurement equipment only, for example as described in ISO 230-1:2012, 11.3.4. Results from circular tests using a feedback signal are designated as “bi-directional circular error using feedback signal G(b)_f” (see Annex E).

3.4

circular error

circular deviation

G

minimum radial separation of two concentric circles enveloping the actual path (3.2) (minimum zone circles) of a clockwise or anticlockwise (counter-clockwise) contoured path

Note 2 to entry: Note 2 to entry to Note 6 to entry for bi-directional circular error G(b) (3.3) apply for circular error G. For differences between the circular error G and the radial error F (3.5) , see Annex A, Table A.1.

Note 3 to entry: Designation G is for measurements with external measurement equipment, for example as described in ISO 230-1:2012, 11.3.4, only. Results from circular tests using feedback signal shall be designated circular error using feedback signal G_f, see Annex E.

3.5

radial error

radial deviation

F

deviation between the actual path (3.2) and the nominal path (3.1) ここで, the centre of the nominal path is obtained either a) from the centring of the measuring instruments on the machine tool or b) from the least squares centring analysis for a full circle only

Note 2 to entry: Positive deviations are measured away from the centre of the circle and negative ones towards the centre of the circle (see Figure 3). The radial error is given by the maximum value, F_max, and the minimum value, F_min.

Note 3 to entry: Set-up errors can be included in the radial error F; this is applicable only where the centre of the nominal path is obtained from the centring of the measuring instrument on the machine tool [option a) of the definition].

Note 4 to entry: For differences between the radial error F and the circular error G (3.4) , see Annex A, Table A.1.

3.6

mean bi-directional radial error

mean bi-directional radial deviation

D

difference between the radius of the least squares circle of two full circle actual paths (3.2) ここで, one path is carried out by a clockwise contouring motion and the other one by an anticlockwise (counter-clockwise) contouring motion, and the radius of the nominal path (3.1)

Note 1 to entry: For differences between mean bi-directional radial error D and bi-directional circular error G(b) (3.3), see Annex A, Table A.1.

3.7

identification of axes

designation of the axes which are moved to produce the actual path (3.2)

3.8

sense of contouring for circular tests with linear axes

<clockwise/anticlockwise (counter-clockwise) contouring> sequence of indices denoting the direction of contouring

Note 1 to entry: The order of the indices matches the order in which the circular arc crosses the positive extreme of each axis. For example, G_XY denotes the anticlockwise (counter-clockwise) circular error (3.4) , because an anticlockwise (counter-clockwise) arc in the XY plane crosses the X+ axis immediately followed by the Y+ axis. Similarly, G_YX denotes the clockwise circular error (3.4) , because a clockwise arc in the XY plane crosses the Y+ axis immediately followed by the X+ axis. In the case of a bi-directional result, the indices denote the direction of the first arc.

3.9

contouring interpolation error

contouring interpolation deviation

E_int

range of deviations of the tool centre point trajectory from the fixed point in the workpiece coordinate system (3.11) , when a rotary axis (or axes) is (are) driven, synchronously with interpolated circular motion with linear axes, such that the tool centre point nominally stays at this fixed point in the workpiece coordinate system (3.11)

Note 1 to entry: Typical test methods are described in ISO 230-1:2012, 11.3.5. Typical measuring instruments are described in ISO/TR 230-11:2018, 12.2.1, 12.3.3 and 12.3.4.

Note 2 to entry: If the length-measuring device (ball bar, linear displacement sensor or nest of three linear displacement sensors) is rotated with a rotary axis, the measurements are taken in the coordinate system attached to the rotary axis, i.e. in radial, tangential and/or axial direction. This is specified by E_int,radial, E_{int,tangential} and E_int,axial.

Note 3 to entry: If the length-measuring device (ball bar, linear displacement sensor or nest of three linear displacement sensors) is not rotated with a rotary axis, the measurements are taken in X, Y and Z directions of the machine coordinate system (3.10) . This is specified by E_int,X, E_int,Y and E_int,Z.

Note 4 to entry: The axes moved are specified by giving the nomenclature of the axes. For example, a measurement with linear axes X and Y and rotary axis C in radial direction is specified by E_{int,radial,XYC}. A measurement with three linear axes X, Y, Z and two rotary axes A, C in radial direction corresponds to a spherical test according to ISO 230-1:2012, 11.5 and is specified by E_{int,radial,XYZAC.}

Note 5 to entry: Clockwise or anticlockwise (counter-clockwise) movement is defined by the rotary axes if there is just one rotary axis moved. If two rotary axes are moved, clockwise and anticlockwise (counter-clockwise) are defined by the axis that moves over a larger range, generally the axis that moves over 360°. Clockwise is specified by CW, anticlockwise (counter-clockwise) is specified by CCW. For a clockwise measurement with the axes X, Y and C in radial direction the specification is E_{int,radial,XYC(CW)}.

Note 6 to entry: Precautions for test set-ups for circular tests with rotary axes are given in Annex C.

3.10

machine coordinate system

MCS

right-hand rectangular system with the three principal axes labelled X, Y and Z, with rotary axes about each of these axes labelled A, B and C, respectively

Note 1 to entry: The machine coordinate system is prescribed by ISO 841 for many machine tools.

[SOURCE:ISO 230-1:2012, 3.2.1, modified — figure deleted and Note 1 to entry added.]

3.11

workpiece coordinate system

WCS

Cartesian coordinates fixed on the workpiece

Note 1 to entry: When a machine tool has the rotary axis (axes) on the workpiece side, the workpiece coordinate system is rotated with the rotary axis (axes).

[SOURCE:ISO 2806:1994, 2.7.3, modified — Note 1 to entry added.]