- 學位論文
利用 ZigBee 定位技術有效控制自走車導引誤差之研究
An Effective Guidance Scheme of Mobile Robot Using Self-Adjustment Error ZigBee Positioning System
摘要
近年來室內定位系統已大幅應用在室內無人搬運車及醫療照護機器人等自走裝置系統之應用中。而自走裝置系統的研究一般分為移動前的定位方法及定位後的機構移動控制兩項技術。目前機構移動控制的技術發展成熟，移動誤差已可有效控制在應用所需範圍內。因此自走裝置採用不同的室內定位技術所造成之誤差大小，將成為自走裝置實際移動位置與預設目的地之間距離誤差的主要來源。而本文所使用之自我調整誤差定位法其最大定位誤差已可大幅縮小至 85 公分以內，但在進行定位時必須注意其ZigBee 硬體設備所使用之天線類型及其擺放角度。因此本文將先針對ZigBee 模組上兩種常見天線類型，印刷式(隱藏式)天線及外接式直線天線的送收特性及其擺放角度對於通道模型建立的影響進行分析與研究。進而選擇出適用於自走裝置系統之自我調整誤差定位法使用的天線類型。為進一步確認不同天線特性進行自我調整誤差定位法時是否會導致定位系統判斷錯誤的情況產生。本研究將從實驗結果選擇具有指向選擇特性之天線來建立自走裝置之定位系統。但自我調整誤差定位法的定位誤差雖然可達15至 85 公分之間，但對於應用於自走裝置之定位系統時動力移動機構與目的地實際誤差將達約70cm之變動量。本文將針對自走裝置定位系統提出中繼區域移動策略加入於自我調整誤差定位法中，藉以有效縮小動力移動機構實際到達目的地時與預計目的地誤差變動量。文中將針對中繼區域移動策略提出三種不同中繼次數策略並進行目的地定位誤差分析，藉以了解誤差改善效果之程度。分別從實驗數據模擬與實際環境進行自走裝置定位系統驗證，將證明中繼區域移動策略確實能改善目的地誤差。更進一步比較三種不同中繼次數策略，進而從中找出最合適之策略應用於自我調整誤差定位法中，對於未來利用ZigBee技術做為自走裝置系統之應用提供一有效之方法。
並列摘要
Indoor localization systems recently have been widely used in indoor mobile robot devices, such as Automated Guided Vehicle Systems(AGVSs), healthcare robotics. In the previous studies, mobile robot systems are divided into two aspects of techniques, the positioning technique of the robot devices to solve its location and the moving control technique of the robot devices to move to the planed destination correctly. So far, the moving control techniques have been well developed to its mechanism with minimized the error of moving distance. However, the error of moving is mainly caused by the positioning technique, especially in indoor environments. To improve the positioning error of distance, a self-adjustment error indoor positioning method was proposed. In the previous study, the positioning error is reduced to below 85 cm. In our research, we will use the method to the positioning technique of the robot devices. But it was not considered the effect of positioning error as different antenna types mounted on the ZigBee modules. First, in this paper, we will discuss the features of different antenna types as used in the same self-adjustment error indoor positioning method and then to analyze and compare the transmission characteristics and placed direction of the antenna printed on PCB and the external linear antenna mounted on PCB. As the results, we will select the suitable type of antenna to use in the mobile robot device systems. As shown in the paper, the self-adjustment error indoor positioning method can reduce the position error between 15 and 85 cm. But it still has the variation up to 70cm between the real moved mobile robot and the planed destination. In this paper, we will propose a turning-point strategy to reduce the variation between the mobile robot and the planed destination. In the proposed strategy, we will present three different turning-point enter-times strategies to identify the most appropriate turning-point strategy. In order to find out the best enter-times strategy, the numerical simulations and the real environment experiments will be performed. In comparison with results, the best solution will be decided to add into the self-adjustment error indoor positioning method. Finally, our proposed scheme will provide a valuable solution for the applications of indoor mobile robot devices.