Design and Characterisation of a Fast Steering Mirror Compensation System Based on Double Porro Prisms by a Screw-Ray Tracing Method

Laser sensors can be used to measure distances to objects and their related parameters (displacements, position, surface profiles and velocities). Laser sensors are based on many different optical techniques, such as triangulation, time-of-flight, confocal and interferometric sensors. As laser sensor technology has improved, the size and cost of sensors have decreased, which has led to the widespread use of laser sensors in many areas. In addition to traditional manufacturing industry applications, laser sensors are increasingly used in robotics, surveillance, autonomous driving and biomedical areas. This paper outlines some of the recent efforts made towards laser sensors for displacement, distance and position.

Section: Contributionsmentioning

confidence: 99%

Laser Sensors for Displacement, Distance and Position

Suh

2019

“…Next, the mathematical model derivation is briefly introduced along with its characteristics. Further information about the mathematical model can be found in our previous papers [29,30,31,32,33]. Our mathematical models are built using the skew-ray tracing method and a homogeneous transformation matrix (HTM).…”

Section: Numerical Simulation and Mathematical Modelmentioning

confidence: 99%

“…Following the algorithm for the flat-boundary skew-ray tracing method, shown in our previous publication [29,30,31,32,33], AiR denotes the transfer matrix from each optical device (i) coordinate system to the reference coordinate system (R), and is given as:AiR=[IixIiyIiz0JixJiyJiz0KixKiyKiz0tixtiytiz1]…”

Section: Numerical Simulation and Mathematical Modelmentioning

confidence: 99%

Design of a Measurement System for Six-Degree-of-Freedom Geometric Errors of a Linear Guide of a Machine Tool

Liu

Lai

Luo

2018

Self Cite

This paper proposes a system utilizing a Renishaw XL80 positioning error measuring interferometer and sensitivity analysis design to measure six-degree-of-freedom (6 DOF) geometric errors of a machine tool’s linear guide. Each error is characterized by high independence with significantly reduced crosstalk, and error calculations are extremely fast and accurate. Initially, the real light path was simulated using Zemax. Then, Matlab’s skew ray tracing method was used to perform mathematical modeling and ray matching. Each error’s sensitivity to the sensor was then analyzed, and curve fitting was used to simplify and speed up the mathematical model computations. Finally, Solidworks was used to design the set of system modules, bringing the proposed system closer to a product. This system measured actual 6 DOF geometric errors of a machine tool’s linear guide, and a comparison is made with the Renishaw XL-80 interferometer measurements. The resulting pitch, yaw, horizontal straightness, and vertical straightness error deviation ranges are ±0.5 arcsec, ±3.6 arcsec, ±2.1 μm, and ±2.3 μm, respectively. The maximum repeatability deviations for the measured guide’s pitch, yaw, roll, horizontal straightness, vertical straightness, and positioning errors are 0.4 arcsec, 0.2 arcsec, 4.2 arcsec, 1.5 μm, 0.3 μm, and 3 μm, respectively.

“…The influence of the laser beam pointing stability can be eliminated by splitting up the laser beam and monitoring one beam with a reference detector [ 20 ], control the beam with an active laser beam stabilization system [ 21 , 22 ] or a thermo-mechanical beam drift stabilization [ 23 ], as well as splitting up the laser beam into two parallel beams [ 15 , 24 , 25 ]. The latter of those options also compensates for errors due to atmospheric turbulence or air refractive index gradients.…”

Section: Introductionmentioning

confidence: 99%

Optical Setup for Error Compensation in a Laser Triangulation System

Kienle

Batarilo

Akgül

et al. 2020

Absolute distance measurement is a field of research with a large variety of applications. Laser triangulation is a well-tested and developed technique using geometric relations to calculate the absolute distance to an object. The advantages of laser triangulation include its simple and cost-effective setup with yet a high achievable accuracy and resolution in short distances. A main problem of the technology is that even small changes of the optomechanical setup, e.g., due to thermal expansion, lead to significant measurement errors. Therefore, in this work, we introduce an optical setup containing only a beam splitter and a mirror, which splits the laser into a measurement beam and a reference beam. The reference beam can then be used to compensate for different error sources, such as laser beam dithering or shifts of the measurement setup due to the thermal expansion of the components. The effectiveness of this setup is proven by extensive simulations and measurements. The compensation setup improves the deviation in static measurements by up to 75%, whereas the measurement uncertainty at a distance of 1 m can be reduced to 85 μm. Consequently, this compensation setup can improve the accuracy of classical laser triangulation devices and make them more robust against changes in environmental conditions.