Improving Angular Accuracy of a Scanning Mirror Based on Error Modeling and Correction

Abstract

Scanning mirrors appear to be key components in optoelectronic systems for line-of-sight (LOS) stabilization. For improving the angular accuracy of a scanning mirror based on the eddy current displacement sensor measurement, an angular error-correction method is proposed and demonstrated. A mathematic angular error model with physical parameters was developed, and the cross-validation method was employed to determine the reasonable order of the Maclaurin series used in the error model, which increased the exactitude and robustness of the correction method. The error parameters were identified by accurately fitting the calibrated angular errors with the error model, which showed excellent error prediction performance. Based on the angular calculation model corrected by the error model, the closed-loop control system was established to obtain accurate deflection angles. Experimental results show that within the deflection angle of ±1.5 deg, the angular accuracy was improved from 0.28 deg to less than 1.1 arcsec, and the standard deviation for six measurements was less than 1.2 arcsec, which indicates that the angle correction method was effective in improving the linearity of the eddy current sensors and reducing the influence of manufacturing and installation errors.

High-Range and High-Linearity 2D Angle Measurement System for a Fast Steering Mirror

“…x 2 + (y − h) 2 + z 2 3 P (15) Supposing that the light distribution curve L obeys second-order normal distribution; then, the light source opening angle is 17°, r = 5.0, L = 7.0, M = 10.0, d = 1.4, D = 3.5, kd = 0.983, β = 0, and θ = α. When α changes from −20° to 20°, the changes in the surface light intensity of a single photodiode in the α and β directions are shown in Figure 6.…”

“…Yue Fan [15] demonstrated an angle measurement method based on an eddy current sensor which achieved an angle measurement accuracy of 1.1 arcsec in the range of ±1.5 • . Lin D. [16] introduced a two-axis measurement system based on the principle of a capacitance sensor, with a measurement range of ±5 • .…”

Tracking Control of a Maglev Vibration Isolation System Based on a High-Precision Relative Position and Attitude Model

“…Eddy current displacement sensors are widely used in precision instruments due to their high sensibility and reliability [26,27]. However, they have a high requirement in terms of the shape and size of the object [28]. Laser displacement sensors also have high sensitivity and a quick response [29], whereas the volume of a laser displacement sensor is too large for a highly integrated maglev vibration isolation system.…”