Estimating Horizontal Rotation Using Dual Triaxial Accelerometers

應用雙三軸加速度計估算水平方向之旋轉

陳俊佐(Chun-Tso Chen)

指導教授 ： 金仲達

國立清華大學/電機資訊學院/資訊系統與應用研究所/碩士(2010年)

摘要

目前三軸加速度計已經廣泛的使用在手持裝置系統中。因為其測量三軸方向加速度的原理，使得許多應用程式將三軸加速度計當作一種人性化的輸入方式。普遍上，這些應用程式測量加速度與重力加速度的夾角變化，用以判斷不同的輸入模式；然而，若無法得知重力加速度，也就是水平方向的旋轉情況就無法得知，這些應用程式必須使用額外的裝置來做為輔助，像是陀螺儀、電子羅盤等等。但是對於手持裝置系統來說，這些額外的裝置會造成多餘的負擔。所以為了克服這些負擔，在此篇論文中提出了一種簡單的系統來估計水平方向上的旋轉，只利用兩顆三軸加速度計來取代這些額外的裝置。藉由牛頓運動定律及向心加速度的公式推導，加上兩顆三軸加速度計所測量的加速度，可以計算出角加速度的變化程度，進而估算出角位移的程度，也就是旋轉的角度變化。此篇論文中設計了數個實驗來呈現結果，並使用電子羅盤作為結果驗證以及比較的對象。

關鍵字

加速度計 ； 角位移 ； 加速度

並列摘要

Accelerometers nowadays have been widely used in mobile devices. Many applications on mobile devices rely on accelerometers for information of the motions, tilt, and states of the devices to provide advanced and interesting functionalities. Most accelerometers are used in conjunction with the gravity, which provides an absolution reference for the accelerated variations of the accelerometers. Without gravitational information, applications need extra devices like magnetic sensors, gyroscopes, and GPS to measure the horizontal rotation. However, these additional devices are much bigger, more expensive, and more easily affected by environment, which are unsuitable for mobile devices. To overcome these constraints, in this thesis, we propose a simple and low-cost method to estimate horizontal rotations of mobile devices by using dual triaxial accelerometers separated by a known and fixed distance. With two triaxial accelerometers, acceleration signals were obtained to estimate the angular displacement by physical equations. Experiments were conducted to evaluate and compare the accuracy of our approach and that of a magnetic sensor.

並列關鍵字

accelerometer ； angular displacement ； acceleration

參考文獻

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