Temperature compensation of position sensitive detector

Abstract

The position sensitive detector(PSD) is photo-electronic sensor which can detect the position of a light spot traveling over its surface, and convert the position of light spot to simple electric current signal. Based upon PSD, many types of precision and contactless motion detection instruments could be constructed. The most important problem to use the PSD is how to overcome the influence of temperature action on the PSD, therefore to improve the precision and reliable of the instrument. The output characteristic of PSD pressure sensor is analyzed. It is found that the response of sensor is non-linear and the sensor suffers from the influence of over a wide measuring range. A method for temperature compensation of PSD sensor voltage based on Neural Network High Accuracy Linearization Sub-block Network Integration Interpolation is presented in this paper. In order to realize temperature compensation over a full range, the neural network is trained to properly represent the nonlinear mapping between sensor reading and their represent output accurately at different temperature It is revealed from the experiment result that not only the influence of temperature fluctuation can be eliminated effectively, but also a desired linear relationship between the sensor input and the neural network output can be obtained.