Mitutoyo Corporation

Takashi Noda

Hiromi Deguchi

Hiroshi Kamitani

Naoya Kikuchi

Katsuyuki Ogura

Norihiko Murata

Kenji Ueda

Nobuhiro Ishikawa

Koji Takesako

Kazumi Mizukami

Motonori Ogihara

Tomohiro Usui

Kozo Sugita

Shoichi Todaka

Tetsuo Kimura

Shinjiro Sakamoto

There is provide a method for controlling a shape measuring apparatus that synchronize an acceleration/deceleration changing timing of a velocity pattern with a control sampling cycle, and prevents a control lag. Based on a shape of a movement path set based on preliminarily-obtained shape data of an object to be measured, a velocity pattern for a probe to move along the movement path. It is determined whether a velocity changing timing of the velocity pattern is synchronized with a control sampling cycle of a shape measuring apparatus. When the velocity changing timing of the velocity pattern is not synchronized with the control sampling cycle, the velocity pattern is corrected such that the velocity changing timing of the velocity pattern is synchronized with the control sampling cycle of the shape measuring apparatus.

Method for controlling shape measuring apparatus

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.

Control method of shape measuring apparatus

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 &#x3b1; and a second rotating angle &#x3b2;. 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.

There is provided a method for controlling a shape measuring apparatus which can achieve both trajectory correcting capability and control stability. A stylus tip is moved along a scanning path while controlling the stylus tip so as to keep an amount of deflection of a probe to a workpiece to be a reference amount of deflection. A movement instruction for the probe is generated according to a combined velocity vector V represented by the following expression:combined velocity vector2,

A probe displacement command in a scanning measurement is generated according to a composite speed vector V:()&#xb7;2

Control method of profile measuring apparatus

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.

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&#x2212;d) multiplied by a coefficient k (0&#x3c;k&#x3c;1) is a proper retraction amount Lr in view of a diameter d of the stylus tip.

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.

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.

Shape measuring apparatus and control method of shape measuring apparatus

Stylus head displacer displaces a stylus head on a first measurement path. A path definer defines the first measurement path. A displacement controller controls the stylus head displacer such that the stylus head displaces along the first measurement path. A position detector detects a position of the stylus head. A depression amount detector detects the depression amount of the stylus head. A measurement results memory stores the position and amount of depression of the stylus head. The depression amount detector outputs an error signal when detecting a measurement error. The displacement controller stops displacement of the stylus head in response to the error signal and displaces the stylus head to a starting point of the first measurement path, and controls the stylus head displacer such that the stylus head is displaced from the starting point to an end point of the first measurement path with a fixed depression amount.

Form measuring apparatus and form measurement method

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.

Form measuring apparatus and measuring method for V groove center

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.

Form measuring apparatus and method of registering coordinate system for rotary table

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.

Shape measuring apparatus

A corrected ball diameter calculating method includes: preparing a reference gauge that has at least one reference peripheral surface of an outer peripheral surface and an inner peripheral surface; valuing of diameter values of the reference peripheral surface at a plurality of different height positions from a bottom surface of the reference gauge; calculating calibrated diameter values per each of the height positions; placing the reference gauge on the rotary table and causing the stylus tip to touch a plurality of measurement sites on the reference peripheral surface at each of the height positions to calculate measured diameter values that are diameter values of a circle passing through the neighborhood of center points of the stylus tip; and calculating the corrected ball diameters per each of the height positions from the calibrated diameter values and the measured diameter values that are calculated per each of the height positions.

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Tochigi, Japan

Takashi Noda