Precision Laser Beam Path Tracking Control System for Position Measurement Using PSD Sensor

Abstract

Position sensitive detector (PSD) is an optical position sensor that can measure a position of the light spot in one or two-dimensions on sensor surface. The PSD is precision semiconductor optical sensor that produces output currents related to the "Centre of mass'' of light incident on the surface of the device used in the measurement there are many advantages including a good positioning accuracy for fast response time and very simple signal conditioning circuits. A precise control system has been designed in this paper using a new and modern algorithm with a closed-loop system to obtain accurate tracking of the position and speed of the radiation used in the measurement of the specific physical process. The proposed control model about laser beam path controlled using a new type of controller named PSD fuzzy controller with feedback through PSD sensor, also the FOC method was applied to the hybrid stepper motor to control the position and speed with four rings feedback. The algorithm will realize better rise time and less overshoot better and detailed analysis is carried out to confirm the viability of the proposed system.

Nonlinear error compensation for 2D PSD based on SSA-BP neural network

“…They can be widely applied in displacement measurement, attitude detection, beam positioning, tracking, and calibration. [1][2][3][4] Due to the working environment and inherent characteristics, the output current of PSD devices often produces nonlinear errors, leading to a decrease in the overall accuracy of the measurement system. [5] To compensatethe nonlinear errors and improve the accuracy of PSD devices, two major types of nonlinear error compensation methods based on hardware system and software system compensation have been proposed.…”