超音波導盲系統之預設座標障礙物位置定位策略

本研究提出一種超音波導盲系統之定位策略，此種創新的定位方法採用多個預設障礙物座標點在有效測量區域內來做定位。當超音波導盲系統中的三個超音波接收器收到障礙物之回波，僅需與已知的預設障礙物座標點比對三組超音波接收器所接收到障礙物回波的時脈計數值，其中皆符合三組容許誤差內的預設障礙物座標點即為候選的障礙物位置。此種定位方法解決了牛頓-拉弗疊代法因少量的時脈誤差而導致嚴重定位偏差的問題，並且適合以運算能力較弱的嵌入式處理器來實現。

關鍵字

超音波；預設障礙物座標點；障礙物；定位

並列摘要

This paper aims to propose a novel positioning strategy of an ultrasonic guiding system for the blind. Many presetting points are located in the effective measurement area of the guiding system. After three ultrasonic receivers catch the echo signals reflected from an obstacle under detection, only simple mathematical calculations and comparison of three clock sets with the presetting points are required to find the position of the obstacle. The presetting points would be candidates for obstacle position if the errors of the three clock sets are all within acceptable margins. This proposed strategy could solve the serious positioning problem in Newton-Raphson iteration method, which is due to a little clock error. Besides, the strategy can be implemented more easily in an embedded system, which is less available for mathematical calculations.