Tow Dimensional Touch-Sensing Navigation System using Picture Processing for Visually Handicapped Person

针对二维触觉导航系统，设计并测试了二维触觉触摸板。触摸针是一种小针头或致动器，视障人士可以在其上用手指触摸来识别信息。该二维触摸板由嵌入树脂板的触摸针的矩阵组成。触敏销的横截面为1平方毫米，可移动0.5毫米。触摸针是由计算机控制的。触敏销的材料为压电晶体，当施加高电压时，触敏销在物理上呈伸展状。我们已经从物理位移、稳健性和电学特性方面考虑了各种压电晶体。因此，行波型超声致动器具有更好的触敏销钉特性，而不是压电晶体。我们使用超声波驱动器(5 mm长)和连接到嵌入式微型计算机的高速驱动电路对二维触觉传感垫进行了测试。因此，触敏针脚的速度为1-5 mm/秒，为衬垫提供了足够的特性。此外，根据环境温度和湿度的不同，每个触摸针的特性都不一致，从而导致粘连现象。

The two-dimensional touch-sensing pad has been designed and tested for a tow-dimensional touch-sensing navigation system. The touch-sensing pin is a small pin or actuator on which a visually-handicapped person can recognize information by touching with his/her finger. The two-dimensional touch-sensing pad consists of a matrix of the touch-sensing pins embedded in a resin-board. The touch-sensing pin has a cross-section of 1 square mm, and can moves 0.5mm. The touch-sensing pins are controlled by a computer. The material of touch-sensing pin is piezoelectric crystal, and it physically extends in shape when high electric voltage is applied on it. We have considered various piezoelectric crystals in terms of physical displacement, robustness, and electrical characteristics. As a result, an ultra-sonic actuator with traveling-wave type has better characteristics for touch-sensing pins rather than piezoelectric crystals. We have tested a two-dimensional Touch-sensing pad using ultra-sonic actuators (5mm length) and high speed driving circuit connected to a embedded microcomputer. As a result, the touch-sensing pins has a velocity of 1-5 mm/sec providing sufficient characteristics for the pad. In addition, each touch sensing pin has no uniform characteristics depending upon ambient temperature and moisture causing sticking phenomena.