Development of a Braille Tactile Device Driven by Linear Magnet Actuators

摘要

A Braille display is an electro-mechanical device representing braille characters, usually by means of round-tipped pins raised through holes in a flat surface. We develop a tactile Braille display device which is able to represent graphical information like simple pictures or computer icons on the users' hand. Generally, the developed mechanical construction of the tactile hand device consists of a frame with flat surface upper plate matrix type with 96 holes and 96 pins, respectively. The pins are driven by linear motion electromagnetic actuators. The pins perform up and down motion with less than 4mm stroke. The main focus of the paper is dedicated on the development and optimization of the linear motion magnetic actuators as well as the design concept of the Braille tactile device. Permanent magnet actuators driven pins in the Braille display matrix are developed and optimized. Moreover, the static force properties and magnetic field distribution of the linear motion actuators are studied in different values of their parameters. The optimization factors include dimensions of the cores and movable parts under additional constraint for overall dimension of the actuator. In order to optimize both construction and performance of the magnet actuators, finite element analysis and experiments have been done. Also, it is proposed a design concept for development of control interface for the Braille tactile device. In addition, mechanisms for testing of each pin performance or linear actuators of braille matrix are designed. These mechanisms are intended to hold sensors. Also, applications of linear magnetic actuators in spatial tactile devices as well as in micro motion robotics are discussed.