Tang Zhifeng

Modelling self-sensing of a magnetostrictive actuator based on a terfenol-D rod

A simplified quasi-static computational model for self-sensing applications of magnetostrictive actuators based on terfenol-D rods is presented. Paths and angle changes in the magnetic moments rotation of Tb0.3Dy0.7Fe2 alloy are studied as functions of compressive stress and magnetic field, and then used to determine the magnetization in its actuation. Then sensing of magnetic induction picked from a driving coil in an actuator is derived. The model is quick and efficient to solve moments rotation and its magnetization. Sensing results of compressive stress and magnetostriction calculated by the model are in good agreement with experiments and will be helpful in the design and control of self-sensing applications in actuators.

Design of Bill Acceptor for Automatic Fare Collecion of Rail Transit

To solve the problem of the not high localization degree of Chinas urban rail transit automatic fare collection systems, a bill acceptor is designed for the rail transit AFC systems. The bill acceptor makes use of magnetic and optical inspection circuit to extract the banknote features like magnetic ink, UV fluorescence, and infrared image. And then apply the PCA algorithm to reduce the dimensionality and build the template. Define two Euclidean distances between the test banknote and the template as the similarity to discriminate the currency. The tests have shown the effectiveness of the system. The banknote jammed rate and receive rate can achieve the industry engineering requirement and the processing speed is significantly improved.