Study on Measurement of Polymer Orientation Degree Base on SVM

Aiming at the difficulty of measuring orientation degree of polymer material online, a soft-sensing approach based on ultrasonic velocity measurement is proposed. Firstly, the ultrasonic velocities of polymer samples are measured using a DSP-based ultrasonic velocity measurement circuit, with the ultrasonic sensor perpendicular to the extrusion direction of polymer material, the orientation degrees of samples are calibrated with infrared spectroscopy, the relationship between the ultrasonic velocities and the orientation degrees are then established based on SVM. With the measurement model and the ultrasonic velocity measured online, the orientation degree of polymer material can then be measured online. Test results in Lab shows that this approach can implement accurate measurement, and the relative error is about 5%.