Abstract: A form measuring instrument measures a form of a surface of an object to be measured using a contact to follow the surface. A pseudo-measurement point acquirer acquires positional coordinates of the reference point of the contact as pseudo-measurement points when the contact touches the object at a plurality of locations. A normal vector generator estimates a surface or line along the pseudo-measurement points from the pseudo-measurement points to calculate normal vectors extending from the pseudo-measurement points to the surface or line. A contact model locator locates contact models which specify the surface form of the contact so as to coincide the pseudo-measurement points with reference points of the contact models and so as to coincide attitudes of the contact on measurement with attitudes of the contact models. A measurement point calculator calculates cross points as measurement points, at which the normal vectors cross the surfaces of the located contact models.

Abstract: A measuring instrument comprising a stylus displaced following a work, the instrument further comprises a corrector for correcting a displacement in the translation axis direction value according to a height detection axis direction value of the stylus position in a plane specified by the height detection axis and the translation axis, the corrector comprising a calibration measuring device that obtains the calibration measurement data including the displacement information of the translation axis direction value corresponding to the height detection axis direction value of the stylus by moving the stylus; a correction parameter setting device that determines a correction parameter best suited for correcting the measurement error due to the vertical movement error of the stylus based on the displacement information of the stylus; and a measurement data correcting device that corrects a measurement data by using the correction parameter.

Abstract: A roundness measuring device obtains an eccentric position of a measured object with respect to a rotation axis in measuring roundness of the measured object by rotating and driving the measured object. The roundness measuring device includes: a measurement acquisition unit obtaining, as measurements, rotation angles of the measured object and distances from the rotation axis to a surface of the measured object, the distance corresponding to the rotating angle; and an eccentricity calculation unit setting a circular correction circle with its center position provided as variable parameters, calculating the center position of the correction circle that minimizes sum of squares of distances between each of the measurements and the correction circle, in a direction from each of the measurements toward the center position of the correction circle, and determining the center position of the correction circle as the eccentric position.

Abstract: A digital signal value is divided to a plurality of zones along a route. A median is computed based on a difference between a digital signal value and a sum of squares of each component of a filter output value for the digital signal values for each zone. A weighting factor for digital signals in each zone is computed and updated based the median for the zone. A filter output value for the digital signal value is obtained by executing filtration using the computed weighting factor.

Abstract: A correction method for correcting measurement error in data obtained when a stylus tip of a measurement apparatus that moves following the height of a workpiece traces the workpiece along a measurement axis, the measurement error having occurred due to stylus movement in a plane defined by the measurement axis and height directions, the method includes a calibration measurement process of obtaining calibration measurement data that includes shift information on the position of the stylus tip, corresponding to the position of the stylus tip in the height directions while the stylus is moved in the correction target plane and a correction-parameter setting process obtaining a correction parameter value optimal to correct the shift information on the position of the stylus tip, included in the calibration measurement data, for each of the sectors obtained by dividing a measurement range in the height directions.

Abstract: A measuring instrument comprising a stylus displaced following a work, the instrument further comprises a corrector for correcting a displacement in the translation axis direction value according to a height detection axis direction value of the stylus position in a plane specified by the height detection axis and the translation axis, the corrector comprising a calibration measuring device that obtains the calibration measurement data including the displacement information of the translation axis direction value corresponding to the height detection axis direction value of the stylus by moving the stylus; a correction parameter setting device that determines a correction parameter best suited for correcting the measurement error due to the vertical movement error of the stylus based on the displacement information of the stylus; and a measurement data correcting device that corrects a measurement data by using the correction parameter.

Abstract: A form measuring instrument measures a form of a surface of an object to be measured using a contact to follow the surface. A pseudo-measurement point acquirer acquires positional coordinates of the reference point of the contact as pseudo-measurement points when the contact touches the object at a plurality of locations. A normal vector generator estimates a surface or line along the pseudo-measurement points from the pseudo-measurement points to calculate normal vectors extending from the pseudo-measurement points to the surface or line. A contact model locator locates contact models which specify the surface form of the contact so as to coincide the pseudo-measurement points with reference points of the contact models and so as to coincide attitudes of the contact on measurement with attitudes of the contact models. A measurement point calculator calculates cross points as measurement points, at which the normal vectors cross the surfaces of the located contact models.

Abstract: A correction method for correcting measurement error in data obtained when a stylus tip of a measurement apparatus that moves following the height of a workpiece traces the workpiece along a measurement axis, the measurement error having occurred due to stylus movement in a plane defined by the measurement axis and height directions, the method comprising the step of: a calibration measurement process of obtaining calibration measurement data that includes shift information on the position of the stylus tip, corresponding to the position of the stylus tip in the height directions while the stylus is moved in the correction target plane; and a correction-parameter setting process of simultaneously obtaining a correction parameter value optimal to correct the shift information on the position of the stylus tip, included in the calibration measurement data, for each of the sectors obtained by dividing a measurement range in the height directions.

Abstract: A signal processing method is disclosed, where, after inputting a measurement data weighted-spline filter formula is selected to calculate an initial value of a spline filter, weight is adjusted, spline filter output is calculated, convergence is judged thereafter. When the weight is not judged converged, the weight is updated and the weight adjusting and spline filter output calculation are repeated, to conduct a robust spline filtering on the measurement data.

Abstract: Method for determining a coordinate system including a preliminary measurement step in which a detector of a coordinate measuring apparatus is used to scan first measurement areas of the device to obtain position coordinate information and the detector is used to scan a second measurement area that is not on a straight line connecting the first measurement areas to obtain position coordinate information; a feature-point detection step of obtaining the position of a feature point in each of the measurement areas according to a result of measurement; a reference-line determination step of obtaining a first reference line according to the position of each feature point in the first measurement areas, and obtaining a second reference line perpendicular to the first reference line and passing through a feature point located in the second measurement area; an origin-setting step; and an axis setting step.

Abstract: A signal processing method is disclosed, where, after inputting a measurement data weighted-spline filter formula is selected to calculate an initial value of a spline filter, weight is adjusted, spline filter output is calculated, convergence is judged thereafter. When the weight is not judged converged, the weight is updated and the weight adjusting and spline filter output calculation are repeated, to conduct a robust spline filtering on the measurement data.

Abstract: A method for determining a coordinate system for a device under measurement comprises: a preliminary measurement step in which a detector of a coordinate measuring apparatus is used to scan first measurement areas which include two or more feature portions of the device under measurement to obtain position coordinate information and the detector is used to scan a second measurement area which includes one or more feature portions that are not on a straight line connecting the first measurement areas to obtain position coordinate information; a feature-point detection step of obtaining the position of a feature point in each of the measurement areas according to a result of measurement; a reference-line determination step of obtaining a first reference line according to the position of each feature point in the first measurement areas, and of obtaining a second reference line perpendicular to the first reference line and passing through a feature point located in the second measurement area; an origin-setting

Abstract: A digital signal value is divided to a plurality of zones along a route. A median is computed based on a difference between a digital signal value and a sum of squares of each component of a filter output value for the digital signal values for each zone. A weighting factor for digital signals in each zone is computed and updated based the median for the zone. A filter output value for the digital signal value is obtained by executing filtration using the computed weighting factor.

Abstract: A signal-processing method is disclosed, where, after inputting a measurement data, weighted spline formula is selected to calculate an initial value of a spline filter, weight is adjusted, a spline filter output is calculated, convergence is judged thereafter. When the weight is judged not converged, the weight is updated and the weight-adjustment and spline filter output calculation are repeated to conduct robust spline filtering on the measurement data.

Abstract: A signal-processing method is disclosed, where, after inputting a measurement data, weighted spline formula is selected to calculate an initial value of a spline filter, weight is adjusted, a spline filter output is calculated, convergence is judged thereafter. When the weight is judged not converged, the weight is updated and the weight-adjustment and spline filter output calculation are repeated to conduct robust spline filtering on the measurement data.

Abstract: The measurement data fairing method includes: determining an interval in which a geometrical element is to be fitted to measurement data; extracting, from the data, interval measurement data of the fitting interval and robustly fitting the element; removing, on the basis of a result of the robust fitting, outlier from the interval measurement data; computing a statistic of a residual of the interval measurement data after the outlier removing step; and removing, as invalid data, measurement data that exceeds a predetermined limit value of the statistic of the residual from the interval measurement data after the outlier removing step on the basis of the statistic of the residual computed in the computing step.

Abstract: The measurement data fairing method comprises: a fitting interval determination step (S14) for determining an interval in which a geometrical element is to be fitted to measurement data; a geometrical element fitting step (S22) for extracting, from the data, interval measurement data of the fitting interval and robustly fitting the element; an outlier removal step (S24) for removing, on the basis of a result of the robust fitting, outlier from the interval measurement data; a statistic computation step (S26) for computing a statistic of a residual of the interval measurement data after the step (S24); and an invalid data removal step (S28) for removing, as invalid data, measurement data that exceeds a predetermined limit value of the statistic of the residual from the interval measurement data after the step (S24) on the basis of the statistic of the residual computed in the step (S26).

Abstract: A coordinate measuring instrument which measures the size and other factors of a work from amount of three-dimensional relative movement between a probe sensor and the work, as well as a method for generating a reference work shape pattern data which is to be used in automatic measurement. The coordinate measuring instrument has a CAD part for converting design data into shape pattern data, a measuring part for generating, by adding measuring conditions to the shape pattern data, measurement information which includes instructions concerning measuring procedure to be output to a controller, and measuring procedure instruction means having a system for setting and inputting the measuring conditions, whereby an optimum measuring program can be formed without necessitating any reference work or actual work.