A system includes a stage, a detector and a measuring device. The stage is configured to hold a substrate. The substrate includes a plurality of tapered structures, and each of the plurality of tapered structures includes a tapered wall between first and second openings at opposite ends of the plurality of tapered structures. The detector is tilted at a first angle and configured to measure light reflected from the tapered wall at about 90 degrees to the tapered wall. The first angle depends at least in part a second angle between the tapered wall and a longitudinal axis running through the tapered structure. The measuring device is configured to determine a characteristic of the tapered wall and whether the characteristic of the tapered wall is above or below a threshold.

An error identification method for identifying an error includes: securing a calibrator having three or more spheres on the table; measuring an initial position of the calibrator with a position measurement sensor tool; calculating a reference angle of each of the rotation axes for positioning the calibrator to a predetermined reference position using a measured value in the measuring; indexing each of the rotation axes individually to a plurality of indexed angles with respect to the reference angle and measuring a center position of a sphere of the calibrator secured on the table at each of the indexed angles with the position measurement sensor tool; and identifying a positioning error and a straightness error of the linear axis, a squareness error between the respective linear axes, and a position error and an inclination error of each of the rotation axes based on a measured value in the indexing.

An apparatus is selectively controlled to insert a check pin into a fastener hole in a workpiece surface and remove the check pin from the fastener hole. The apparatus is a pneumatically actuated apparatus having a pair of press actuators that are selectively operated to press the check pin attached to a check pin holder of the apparatus into a fastener hole in a workpiece, and a pair of remove actuators that are selectively operated to push against the workpiece surface and move the apparatus away from the workpiece surface to remove the check pin attached to the check pin holder from the fastener hole in the workpiece.

An optical system can include an optical arrangement supported by an optical chassis. A flexure arrangement can support the optical chassis relative to a separate structure to maintain a calibrated distance between optical components of the optical arrangement.

Embodiments of the present disclosure disclose a mounting bracket and a self-propelled robot. The mounting bracket includes a housing, a rotating shaft and a magnetic positioning assembly. The housing is provided with an inner cavity. The rotating shaft is configured to rotate about an axis in the inner cavity. The magnetic positioning assembly includes a first magnetic element and a second magnetic element which are respectively arranged on the housing and the rotating shaft. The laser distance sensor is attached to the rotating shaft and configured to rotate about the axis. The mounting bracket is configured to prevent the rotating shaft from deviating from the axis by generating a force between the first magnetic element and the second magnetic element in a radial direction of the rotating shaft.

A modular gage system includes a base plate having an array of holes and a coordinate system to identify each hole. The modular gage system further includes a plurality of risers and at least one form block. Each riser is assigned to a particular hole and the at least one form block is configured to be positioned atop one or more of the risers. Moreover, each form block is assigned to be located over a particular hole.

A method for measuring geometric errors of a numerical control turntable based on a four-station laser tracer system includes: establishing a self-calibration coordinate system and calibrating positions of tracking interferometers; respectively placing each of target lenses at three non-coplanar points that are above the numerical control turntable and keep certain distances from the numerical control turntable, controlling the numerical control turntable to rotate at a certain angular interval θ.sub.j, and based on positions of the tracking interferometers being known after calibration, solving coordinates of each of measurement points in the self-calibration coordinate system using a non-linear least square method; establishing a turntable coordinate system; perform a conversion between the turntable coordinate system and the self-calibration coordinate system; separating six geometric errors of the numerical control turntable using spatial position errors of the three points at a same position and using the linear least squares method.

The present disclosure relates to the field of tools and more particularly to tools used for locating non-visible structural elements. In specific embodiments, the tools are used to locate non-visible structural elements, such as under a roof or behind a wall.

An operation accuracy measuring method for measuring the operation accuracy of a linear motion mechanism includes the steps of placing on a support table a measuring jig having a flat lower surface, a parallel surface opposite and parallel to the lower surface, and a slanted surface joined to the parallel surface through a straight boundary line, adjusting the position of the measuring jig to allow the white light interferometer to observe the parallel surface and the slanted surface simultaneously, capturing images of the parallel surface and the slanted surface with the white light interferometer and observing changes in interference fringes appearing in image sections of the captured images that represent the parallel surface and the slanted surface while the support table is being linearly moved, and the step of deducing the operation accuracy of the linear motion mechanism on the basis of the observed changes in the interference fringes.

A sensor pressing member to which a sensor is attached such that the sensor is exposed toward a measurement target. The sensor pressing member presses the sensor in a first direction relative to the measurement target to bring the sensor into contact with the measurement target. The sensor pressing member includes an elastic body positioned opposite the measurement target with the sensor in between in the first direction. The elastic body includes a cavity therein.