PSD Integrated Calibration Method Based on Annunciator in Vacuum Environment

Abstract

In this paper, an integrated calibration method for position sensitive detector (PSD) of moving support mechanism in vacuum plasma environment is proposed. That is, the PSD is used to track the laser spot to restore the coordinate information of the signal. Firstly, a PSD integrated calibration principle is proposed to reduce the position error of the signaler by tracking laser points with PSD. Then on this basis, due to the spatial declination angle in the PSD imaging model, a spatial declination correction model was established to compensate the spatial declination error. Finally, there are errors occurred in the measurement because of the nonlinearity of PSD, and the improved backpropagation (BP) neural network calibration algorithm is adopted to further correct the errors through the Fletcher–Reeves linear search method to obtain the accurate coordinate information of the annunciator. MATLAB is used to verify the convergence of the calibration algorithm error. Simulation results show that 951 epochs need to be trained by using the traditional BP algorithm to make the position error converge to 0.001 mm. But when using the improved BP algorithm, only 44 epochs are needed.