Abstract: A method and system for simultaneously measuring multiple DOF GEs by a laser. The system comprises a measuring unit and a target mirror unit; the measuring unit comprises a laser emitting module, a polarizing beam splitter, a fixed reflector, a first ?/4 wave plate, a second ?/4 wave plate, a first polarizer, a first photodetector, an interference length measuring module and a 2D angle measuring module. The target mirror unit comprises a beam splitter and a reflector. The laser emitting module generates an emitting light L1. The polarizing beam splitter is used for (1) beam splitting, (2) beam combining, and (3) beam separating. The fixed reflector is used for reflecting backward the reference light L12 propagating only inside the measuring unit to return the reference light L12 to the polarizing beam splitter.

Abstract: A system for simultaneously measuring 3DOF LGEs by a laser and a method therefor, including a measuring unit and a target mirror unit, the measuring unit includes a laser emitting module, a polarizing beam splitter, a fixed reflector, a first photodetector, and an interference length measuring module; the target mirror unit includes a reflector; the laser emitting module generates an emitting light L1, the polarizing beam splitter is used for 1) “beam splitting” comprising splitting the emitting light L1 into a measuring light L11 and a reference light L12, the measuring light L11 is incident on the target mirror unit and is reflected back by the target mirror unit, so as to return to the measuring unit with a 3DOF LGEs signal; and 2) “beam combining” making the measuring light L11 and the reference light L12 superposed with each other at a spatial position, so as to form a combined beam L3; by measuring a position, frequency and phase drifts of the light L3, the 3DOF LGEs of a space object moving linearly al

Abstract: A method for full-field measurement using Doppler imaging, comprising the following steps: turning on a laser and adjusting the laser; adjusting a spatial filter to obtain circular laser spots having uniform intensity distribution; adjusting a quarter-wave plate and a whole polarizer in a system, and requiring two beams in a reference object and a measured object having different frequencies and perpendicular polarization directions; applying slight pressure to the measured object, setting a charge coupled device (CCD) camera into a continuous acquisition mode, observing interference fringes, and adjusting a light path so that the fringes are clear and visible; setting the sampling frequency, sampling time, captured image format and resolution size of the CCD camera; turning on a lithium niobate crystal drive power switch to produce a heterodyne carrier frequency; applying continuous equal pushing force to the measured object by means of piezoelectric ceramics (PZT) so as to make the measured object produce c

Abstract: A method for full-field measurement using Doppler imaging, comprising the following steps: turning on a laser and adjusting the laser; adjusting a spatial filter to obtain circular laser spots having uniform intensity distribution; adjusting a quarter-wave plate and a whole polarizer in a system, and requiring two beams in a reference object and a measured object having different frequencies and perpendicular polarization directions; applying slight pressure to the measured object, setting a charge coupled device (CCD) camera into a continuous acquisition mode, observing interference fringes, and adjusting a light path so that the fringes are clear and visible; setting the sampling frequency, sampling time, captured image format and resolution size of the CCD camera; turning on a lithium niobate crystal drive power switch to produce a heterodyne carrier frequency; applying continuous equal pushing force to the measured object by means of piezoelectric ceramics (PZT) so as to make the measured object produce c

Abstract: The invention relates to an online measurement system and method for multiple parameters of a wheel based on structured light. The measurement system comprises a wheel sensor, a first wheel online measurement device and a second wheel online measurement device, and is characterized in that both the first wheel online measurement device and the second wheel online measurement device comprise a tread structured light unit, a profile structured light unit and a two-dimensional image sensor. The tread structured light unit and the profile structured light unit project a profile contour curve and a tread contour curve on the wheel, the two-dimensional image sensor takes images, three-dimensional reconstruction is performed on the images to obtain tread contour information and profile contour information, and the wheel diameter, the wheel flange height and the wheel flange thickness are acquired according to the obtained contour information.

Abstract: A method for full-field measurement using Doppler imaging, comprising the following steps: turning on a laser and adjusting the laser; adjusting a spatial filter to obtain circular laser spots having uniform intensity distribution; adjusting a quarter-wave plate and a whole polarizer in a system, and requiring two beams in a reference object and a measured object having different frequencies and perpendicular polarization directions; applying slight pressure to the measured object, setting a charge coupled device (CCD) camera into a continuous acquisition mode, observing interference fringes, and adjusting a light path so that the fringes are clear and visible; setting the sampling frequency, sampling time, captured image format and resolution size of the CCD camera; turning on a lithium niobate crystal drive power switch to produce a heterodyne carrier frequency; applying continuous equal pushing force to the measured object by means of piezoelectric ceramics (PZT) so as to make the measured object produce c

Abstract: The present invention discloses a laser measurement system and method for measuring a six-degree-of-freedom geometric error of a rotating shaft.

Abstract: A method for full-field measurement using Doppler imaging, comprising the following steps: turning on a laser and adjusting the laser; adjusting a spatial filter to obtain circular laser spots having uniform intensity distribution; adjusting a quarter-wave plate and a whole polarizer in a system, and requiring two beams in a reference object and a measured object having different frequencies and perpendicular polarization directions; applying slight pressure to the measured object, setting a charge coupled device (CCD) camera into a continuous acquisition mode, observing interference fringes, and adjusting a light path so that the fringes are clear and visible; setting the sampling frequency, sampling time, captured image format and resolution size of the CCD camera; turning on a lithium niobate crystal drive power switch to produce a heterodyne carrier frequency; applying continuous equal pushing force to the measured object by means of piezoelectric ceramics (PZT) so as to make the measured object produce c

Abstract: The invention relates to an online measurement system and method for multiple parameters of a wheel based on structured light. The measurement system comprises a wheel sensor, a first wheel online measurement device and a second wheel online measurement device, and is characterized in that both the first wheel online measurement device and the second wheel online measurement device comprise a tread structured light unit, a profile structured light unit and a two-dimensional image sensor. The tread structured light unit and the profile structured light unit project a profile contour curve and a tread contour curve on the wheel, the two-dimensional image sensor takes images, three-dimensional reconstruction is performed on the images to obtain tread contour information and profile contour information, and the wheel diameter, the wheel flange height and the wheel flange thickness are acquired according to the obtained contour information.

Abstract: A laser measurement system and method for measuring a six-degree-of-freedom geometric error of a rotating shaft includes a laser emission unit, a six-degree-of-freedom error measurement unit, a six-degree-of-freedom error sensing unit and a servo tracking unit capable of being installed on the rotating shaft to be measured, in which the error measurement unit enables light to be emergent from the error sensing unit and generates a measuring signal according to emergent light and reflected light and backward reflected light of the error sensing unit, and the servo tracking unit includes a four-dimensional adjustment mechanism for realizing four-dimensional adjustment; a motor fixedly installed on the adjustment mechanism; an angle measurement sensor for measuring a rotation angle of the motor; an installation plane fixed on the adjustment mechanism, coaxially rotating with the motor and used for installing the error sensing unit; and a control circuit for controlling the servo tracking unit according to the me

Abstract: A laser measurement system for measuring up to 21 geometric errors, in which a six-degree-of-freedom geometric error simultaneous measurement unit and a beam-turning unit are mounted on either the clamping workpiece or the clamping tool, while an error-sensitive unit is mounted on the remaining one, the beam-turning unit has several switchable working postures and multi-component combinations in its installation state, it can split or turn the laser beam from the six-degree-of-freedom geometric error simultaneous measurement unit to the X, Y, and Z directions in a proper order, or the beam-turning unit can split or turn a beam from the error-sensitive unit to the six-degree-of-freedom geometric error simultaneous measurement unit. The present invention is of simple configuration and convenient operation. Up to 21 geometric errors of three mutual perpendicular linear motion guides are obtained by a single installation and step-by-step measurement.

Abstract: A six degree of freedom laser simultaneous measurement system, wherein a laser emitting unit is separated from a fixed sensor head; the laser emitting unit is connected with the fixed sensor head by a single polarization maintaining fiber; a moving unit comprising the reflector and the beam splitter is mounted on the linear guide; utilizing of the single polarization maintaining fiber, which connects the laser emitting unit with the fixed sensor head, reduces the influence of heat generated by laser source on the measurement accuracy, and makes the system more compact and integrated. The six degree of freedom errors, including position error, horizontal and vertical straightness errors, pitch, raw and roll, can be measured simultaneously by only one incident light. The non-cable connection on the moving unit makes long-distance and in-situ measurement possible.

Abstract: A laser measurement system for measuring up to 21 geometric errors, in which a six-degree-of-freedom geometric error simultaneous measurement unit and a beam-turning unit are mounted on either the clamping workpiece or the clamping tool, while an error-sensitive unit is mounted on the remaining one, the beam-turning unit has several switchable working postures and multi-component combinations in its installation state, it can split or turn the laser beam from the six-degree-of-freedom geometric error simultaneous measurement unit to the X, Y, and Z directions in a proper order, or the beam-turning unit can split or turn a beam from the error-sensitive unit to the six-degree-of-freedom geometric error simultaneous measurement unit. The present invention is of simple configuration and convenient operation. Up to 21 geometric errors of three mutual perpendicular linear motion guides are obtained by a single installation and step-by-step measurement.

Abstract: A six degree of freedom laser simultaneous measurement system, wherein a laser emitting unit is separated from a fixed sensor head; the laser emitting unit is connected with the fixed sensor head by a single polarization maintaining fiber; a moving unit comprising the reflector and the beam splitter is mounted on the linear guide; utilizing of the single polarization maintaining fiber, which connects the laser emitting unit with the fixed sensor head, reduces the influence of heat generated by laser source on the measurement accuracy, and makes the system more compact and integrated. The six degree of freedom errors, including position error, horizontal and vertical straightness errors, pitch, raw and roll, can be measured simultaneously by only one incident light. The non-cable connection on the moving unit makes long-distance and in-situ measurement possible.