Abstract:
A form measuring apparatus includes a probe for measuring a measured object; a rotary table on which the measured object is placed; and a coordinate system calculator calculating coordinate axes configuring a coordinate system for the rotary table. The coordinate system calculator calculates, based on a position of a master ball fixated to the rotary table, a center of a circle traced by the master ball when the rotary table is rotated; calculates a rotary table coordinate system having the center of the circle as an origin point; and corrects coordinates of the origin point based on a calibrated diameter value of a gauge fixated to the rotary table, a first diameter value of the gauge measured by a first measurement in which the probe approaches the gauge in a first direction, and a second diameter value of the gauge measured by a second measurement.
Abstract:
A shape measuring apparatus includes: a probe having a stylus tip; a movable mechanism configured to move the stylus tip; an information acquiring unit configured to acquire design information of a workpiece; a path setting unit configured to set a path of the stylus tip; a path component calculating section configured to calculate a path velocity vector; a push direction component calculating section configured to detect a deflection, and calculate a push correction vector; a locus correction component calculating section configured to detect an amount and a direction of locus deviation of the probe from the path, and calculate a locus correction vector; a velocity synthesizing section configured to calculate a velocity synthesis vector by combining the path velocity vector, the push correction vector, and the locus correction vector; and a drive control unit configured to move the probe according to the velocity synthesis vector.
Abstract:
There is provided a method for controlling a shape measuring apparatus which continues to perform nominal scanning measurement to a workpiece having a slightly large deviation from a design data. A scanning path to move a stylus tip is calculated based on design data of a workpiece. The stylus tip is moved along the scanning path. It is monitored whether a distance between the scanning path and an actual workpiece is excessive. When the distance between the scanning path and the actual workpiece is excessive, a trajectory difference error is generated. When the trajectory difference error is generated, geometric correction is performed to the design data so that the design data approaches to the actual workpiece. Scanning measurement is performed based on the design data after the geometric correction.
Abstract:
A method for nominal scanning measurement includes allowing a user to select a shape of an object to be measured from a geometric shape menu prepared in advance, allowing the user to input, according to the selected geometric shape, a parameter to specify the geometric shape, allowing the user to select a measurement path from a measurement path menu prepared in advance, allowing the user to input, according to the selected measurement path, a parameter to specify the measurement path, calculating, based on the selected geometric shape, the input parameter of the geometric shape, the selected measurement path, and the input parameter of the measurement path, measurement points on a workpiece and a normal line direction at each of measurement points using a calculation formula prepared in advance, and calculating a path for scanning measurement to move while scanning a sequence of the measurement points.
Abstract:
A control method of a shape measuring apparatus divides a curve indicating a movement path of a probe into a plurality of sections. A measurement target section is selected from the plurality of sections sequentially from a starting point side of the curve indicating the movement path of the probe. A first curvature radius is calculated from a curvature of the measurement target section. A second curvature radius is calculated according to an angle between a first straight line connecting a starting point to an ending point of the measurement target section and a second straight line connecting a starting point to an ending point of a section next to the measurement target section. A smaller value from among the first curvature radius and the second curvature radius is set as an effective radius. A maximum speed of probe movement increasing according to an increase in the effective radius is calculated for the measurement target section.
Abstract:
A scanning path is divided after every predetermined number of segments and a set of measurement commands is defined for each of the predetermined number of segments. While executing the measurement command, a speed pattern plan is created for the following measurement command. At this time, planning is conducted such that a final speed of a speed pattern plan of the measurement command is the same as an initial speed of the speed pattern plan of the following measurement command. While executing the measurement command, a gap time (from a current time to an estimated end time of the measurement command) is calculated continuously. When the gap time is longer than a planning calculation time, the initial speed of the speed pattern plan of the following measurement command is kept the same as the final speed of the speed pattern plan of the measurement command.
Abstract:
A probe displacement command in a scanning measurement is generated according to a composite speed vector V: V=Gf·Vf+Ge·Ve+sp(p)·Gc·Vc2 wherein Vf is a vector along which a probe is displaced along a scanning path, Ve is a vector maintaining a deflection amount of the probe toward a work piece at a standard deflection amount. Vc2 is represented by (Vc1·q)q, Vc1 is a vector in a direction correcting a probe position such that a stylus tip is oriented along a scanning course, q is a vector given by a vector product of the normal line of a surface of the work piece and Vf, The normal direction of a measured surface is designated as Nw, p is a scalar product of Vc2 and Nw, and sg(p) is a function returning +1 or −1 in accordance with a value of p.
Abstract:
Controller executes a first scanning control, causing a driver to move a probe such that a tip scans along an inclined surface of a V groove to approach a center of the V groove, and a second scanning control, causing the driver to move the probe such that the tip scans along the inclined surface of the V groove to approach the center of the V groove from a side opposite that of the first scanning control. Angle calculator calculates an angle created between a direction of a deflection vector of the probe and a predetermined direction. Threshold value-correspondent coordinate obtainer obtains coordinates of the tip where the angle has changed to exceed a first threshold value during execution of the first scanning control and obtains coordinates of the tip where the angle has changed to exceed a second threshold value during execution of the second scanning control.
Abstract:
A shape measuring apparatus includes a probe head that changes its posture by rotational motion of a first drive axis and a second drive axis, and a coordinate measuring machine that three-dimensionally displaces a location of the probe head by three translation axes (a third drive axis, a fourth drive axis, and a fifth drive axis). The location of a measurement tip is given by coordinate values of the third to fifth drive axes, and the posture of a probe head is given by a first rotating angle α and a second rotating angle β. An intersection point between a first rotation axis and a second rotation axis is set as a rotation center Q. An interpolation point in each control period is calculated for each of the first to fifth drive axes.
Abstract:
During a retraction where a stylus tip separates from a work piece from a state where the stylus tip and the work piece are in contact, whether there is contact between the stylus tip and the work piece is monitored. When the contact between the stylus tip and the work piece is detected during the retraction, a probe is displaced to a position where the stylus tip does not come in contact with the work piece and a recovery process is executed. When a distance between a point on a surface of the work piece at a retraction start point and a contact point between the stylus tip and the work piece is Lm, and a value defined by (Lm−d) multiplied by a coefficient k (0