摘要:
A method for estimating an absolute distance between a tracking laser interferometer and a retroreflector is provided. The tracking laser interferometer includes the retroreflector for reflecting and returning an incident measurement light in an incident direction and a two-axis rotating mechanism for rotationally moving in an exit direction of the measurement light so that optical axes of the measurement light and return light are collimated.
摘要:
To provide a method for estimating an absolute distance L between a tracking laser interferometer and a retroreflector 70, the tracking laser interferometer including; the retroreflector 70 for reflecting and returning incident measurement light A in an incident direction; and a two-axis rotating mechanism 40 for rotationally moving in an exit direction of the measurement light A so that optical axes of the measurement light A and return light B are collimated, which outputs a measurement value according to an increase or decrease in the distance between the interferometer and the retroreflector 70, wherein the absolute distance L between the interferometer and the retroreflector 70 is estimated by performing arithmetic operation based on an angular position variation θ2 of the two-axis rotating mechanism 40 when a deviation amount d of the return light B from the retroreflector 70 relative to a predetermined position is given as a predetermined value d2. This enables an appropriate increase or decrease of the control amount of a tracking control according to a distance between the interferometer and the retroreflector without forcing an operator to perform a troublesome origin return operation and adding an expensive absolute distance sensor.
摘要:
An optical-axis deflection type laser interferometer includes a reference ball serving as a measurement reference, a retroreflecting means disposed at an object to be measured, a laser interferometer length measuring apparatus that outputs a measurement value according to an increase or a decrease in distance between the apparatus and the retroreflecting means, and a rotational mechanism that rotates a beam projected from the laser interferometer length measuring apparatus around the reference ball. The thus structured laser interferometer measures a distance between the laser interferometer and the retroreflecting means that makes an optical axis of an outgoing beam projected from the laser interferometer length measuring apparatus mounted on the rotational mechanism and an optical axis of a return beam returned to the laser interferometer length measuring apparatus parallel to each other, based on center coordinates of the reference ball. The laser interferometer is characterized by additionally including a displacement gauge that measures an error caused by a relative motion between the reference ball and the laser interferometer length measuring apparatus, and a rectilinear movement mechanism that displaces these in a direction of an optical axis of a measurement beam with respect to the reference ball while maintaining a relative positional relationship between the laser interferometer length measuring apparatus and the displacement gauge. With this structure, it becomes possible to calibrate the displacement gauge used to correct an error in the direction of the optical axis resulting from the motion accuracy of the two-axis rotational mechanism with respect to the reference ball of the optical-axis deflection type laser interferometer, without preparing a special calibrating device, on the operating instrument. As a result, traceability is secured.
摘要:
An optical-axis deflection type laser interferometer includes a reference ball serving as a measurement reference, a retroreflecting means disposed at an object to be measured, a laser interferometer length measuring apparatus outputting a measurement value between the apparatus and the retroreflecting means, and a rotational mechanism that rotates a beam projected from the laser interferometer length measuring apparatus around the reference ball. The laser interferometer additionally includes a displacement gauge that measures an error caused by a relative motion between the reference ball and the laser interferometer length measuring apparatus, and a rectilinear movement mechanism that displaces these in a direction of an optical axis of a measurement beam with respect to the reference ball while maintaining a relative positional relationship between the laser interferometer length measuring apparatus and the displacement gauge. With this structure, calibrating the displacement gauge without preparing a special calibrating device becomes possible, thereby securing traceability thereby securing traceability.
摘要:
An optical axis polarization type laser interferometer including a reference sphere which forms a reference of measurement, a retro-reflecting means disposed at a measurement object, a laser interference measuring apparatus for outputting a measurement value corresponding to an increase or a decrease in the distance to and from the retro-reflecting means; and a two-axis turning mechanism for turning an emission beam of the corresponding laser interference measuring apparatus centering around the reference sphere, which measures, with the center coordinates of the reference sphere used as the reference, the distance to and from the retro-reflecting means where the optical axes of the emission beam from the laser interference measuring apparatus mounted on the two-axis turning mechanism and a return beam become parallel to each other, wherein the fixing portion of the first axis turning mechanism installed at the base part of the apparatus is disposed at the inner circumference thereof, the reference sphere is placed at the fixing portion thereof, and at the same time, the moving portion of the first axis turning mechanism is placed at the outer circumference of the fixing portion, and the second axis turning mechanism is mounted on the moving portion thereof. Therefore, complexities in mechanism design can be simplified to a large extent with respect to the first axis turning mechanism that composes the two-axis turning mechanism.
摘要:
An optical axis polarization type laser interferometer including a reference sphere which forms a reference of measurement, a retro-reflecting means disposed at a measurement object, a laser interference measuring apparatus for outputting a measurement value corresponding to an increase or a decrease in the distance to and from the retro-reflecting means; and a two-axis turning mechanism for turning an emission beam of the corresponding laser interference measuring apparatus centering around the reference sphere, which measures, with the center coordinates of the reference sphere used as the reference, the distance to and from the retro-reflecting means where the optical axes of the emission beam from the laser interference measuring apparatus mounted on the two-axis turning mechanism and a return beam become parallel to each other, wherein the fixing portion of the first axis turning mechanism installed at the base part of the apparatus is disposed at the inner circumference thereof, the reference sphere is placed at the fixing portion thereof, and at the same time, the moving portion of the first axis turning mechanism is placed at the outer circumference of the fixing portion, and the second axis turning mechanism is mounted on the moving portion thereof. Therefore, complexities in mechanism design can be simplified to a large extent with respect to the first axis turning mechanism that composes the two-axis turning mechanism.
摘要:
A laser tracking interferometer directs a laser beam to a retroreflector serving as an object to be measured to sense a displacement of the retroreflector using interference with a laser beam back reflected from the retroreflector. The laser tracking interferometer includes: a reference sphere; a carriage that rotates about a center of the reference sphere; a laser interferometer; a displacement gage for providing a displacement signal corresponding to a relative displacement between the reference sphere and the displacement gage; a data processing apparatus for computing a displacement of the retroreflector; a position sensitive detector for providing a position signal corresponding to deviation of a laser beam; and a controller for controlling rotation of the carriage based on the position signal so that the amount of deviation becomes zero.
摘要:
A laser tracking interferometer; a carriage rotatable about a center of the reference sphere; a laser interferometer that provides a retroreflector displacement signal, and a displacement gage that provides a displacement signal. A data processing apparatus computes displacement of the retroreflector with respect to the reference sphere. A position sensitive detector provides a position signal corresponding to the amount of deviation of a laser beam when the laser beam is reflected off the retroreflector back into the laser interferometer and deviated in a direction orthogonal to its optical axis. A controller controls rotation of the carriage based on the position signal from the position detector so that the amount of deviation becomes zero.
摘要:
A tracking type laser interferometer that detects displacement of a retroreflector 300 being an object to be measured by utilizing interference of a laser beam 102 irradiated onto the retroreflector 300 and reflected by the retroreflector 300 in the returning direction, and carries out tracking by means of a two-axis turning mechanism 240 using displacement in the position of the optical axis of the laser beam 102; the same tracking type laser interferometer, includes; a light irradiator 600 that emits a fan-shaped laser light 602 that is fan-shaped including the optical axis of the laser beam 102, is interlocked with turning movements of the two-axis turning mechanism 240 around an axis orthogonal to the center axis of the corresponding fan shape; and a light receptor 620 that has a specific positional relationship with the retroreflector 300 or the light irradiator 600 and receives the fan-shaped laser light. Thereby, tracking can be automatically reset when the tracking is disabled due to a reason such as interruption of laser light or initial adjustment work can be automated when commencing measurement.
摘要:
A tracking type laser interferometer that detects displacement of a retroreflector 300 being an object to be measured by utilizing interference of a laser beam 102 irradiated onto the retroreflector 300 and reflected by the retroreflector 300 in the returning direction, and carries out tracking by means of a two-axis turning mechanism 240 using displacement in the position of the optical axis of the laser beam 102; the same tracking type laser interferometer, includes; a light irradiator 600 that emits a fan-shaped laser light 602 that is fan-shaped including the optical axis of the laser beam 102, is interlocked with turning movements of the two-axis turning mechanism 240 around an axis orthogonal to the center axis of the corresponding fan shape; and a light receptor 620 that has a specific positional relationship with the retroreflector 300 or the light irradiator 600 and receives the fan-shaped laser light. Thereby, tracking can be automatically reset when the tracking is disabled due to a reason such as interruption of laser light or initial adjustment work can be automated when commencing measurement.