Using a Hexagonal Mirror for Varying Light Intensity in the Measurement of Small-Angle Variation

Abstract

Precision positioning and control are critical to industrial-use processing machines. In order to have components fabricated with excellent precision, the measurement of small-angle variations must be as accurate as possible. To achieve this goal, this study provides a new and simple optical mechanism by varying light intensity. A He-Ne laser beam was passed through an attenuator and into a beam splitter. The reflected light was used as an intensity reference for calibrating the measurement. The transmitted light as a test light entered the optical mechanism hexagonal mirror, the optical mechanism of which was created by us, and then it entered the power detector after four consecutive reflections inside the mirror. When the hexagonal mirror was rotated by a small angle, the laser beam was parallel shifted. Once the laser beam was shifted, the hitting area on the detector was changed; it might be partially outside the sensing zone and would cause the variation of detection intensity. This variation of light intensity can be employed to measure small-angle variations. The experimental results demonstrate the feasibility of this method. The resolution and sensitivity are 3 × 10−40 and 4 mW/° in the angular range of 0.6°, respectively, and 9.3 × 10−50 and 13 mW/° in the angular range of 0.25°.

Two-Dimensional Micro-/Nanoradian Angle Generator with High Resolution and Repeatability Based on Piezo-Driven Double-Axis Flexure Hinge and Three Capacitive Sensors

“…The angle is one of the most important basic geometrical quantities in the field of precision engineering [ 1 , 2 , 3 , 4 ]. Various microangle measurement instruments, such as the angle encoder [ 5 , 6 , 7 ], autocollimator [ 8 , 9 ], and angle interferometer [ 10 ], are commonly used in scientific research and industrial metrology to provide accurate angle reference values within the feedback loop of manufacturing and testing processes.…”

Tilt Angle Measurement Based on Arrayed Eddy Current Sensors

“…So the tilt angle measurement based on arrayed EC sensors may be very meaningful. At present, the tilt angle measurement is mostly through the visual and laser methods [10,11], which are very strict with the measurement environment, which means these methods are not suitable for the industrial environment. However, the EC sensor is very suitable for industrial measurement, owning to its strong environmental adaptability.…”