Ihelmet

iHelmet:

On-Site Building Information Retrieval by Using�Projection-Based Augmented Reality

應用投影式擴增實境於現地建築資訊擷取

iHelmet:

On-Site Building Information Retrieval by Using�Projection-Based Augmented Reality

應用投影式擴增實境於現地建築資訊擷取

Related references

1. Yeh, K. C., Tsai, M. H. and Kang, S. C. (2012). "On-site Building Information Retrieval By Using Projection-Based Augmented Reality," Journal of Computing in Civil Engineering, 26(3), 342-355.

2. Yeh, K.C., Tsai, M.H. and Kang, S.C. (2012). “The iHelmet: an AR-enhanced wearable display for BIM information,� Mobile and Pervasive Computing in Construction, WileyBlackwell. (ISBN 978-1-1184-2227-4)

iHelmet 應用投影式擴增實境於現地建築資訊擷取 本研究發明一組可穿戴的投影裝置─iHelmet，目的是要能將建築的相關資訊帶至工地現場使用，以解決在現地 擷取建築資訊的困難與障礙。 iHelmet的硬體部分包含了： 1. 一頂安全帽(約460克) 2. 一台iPod Touch(約115克) 3. 一台LED投影機(約114克) 軟體部分則包含了四大模組，其各自的功能為： 1. 資訊整合模組 ─ 可將BIM的模型轉換成現地使用的影像 2. 展示模組 ─ 可自動調整適當的影像比例，並透過投影機投影出來 3. 定位模組 ─ 讓使用者輸入目前所在位置，再將附近的資訊提供給使用者 4. 操作模組 ─ 讓使用者以觸控手勢進行操作，選擇所需要的資訊 為了驗證iHelmet在工地現場的有效性與效率，我們將iHelmet和傳統2D施工圖進行測試與比較。在34位受測者 當中，我們發現完成同樣的任務，使用iHelmet的平均花費時間較短(使用iHelmet約花費44秒、傳統的約花費 99秒)，且使用iHelmet的完成正確率也較高(使用iHelmet約91.6%、傳統的約64.3%)。

System architecture of the iHelmet Visual Feedback

Display Module Full-Scale Projection

User

Positioning Module

Project

Information Integration Module Image-Based Model

Integrate

BIM Model

Projection Range Distance Value Direct Manipulation

Manipulation Module Multi-Touch Gesture Control User Interface Layer

Data Process Layer

Data Storage Layer

On-Site Building Information Retrieval by Using�Projection-Based Augmented Reality

This research focuses on a long-standing problem at construction sites: on-site information retrieval. A wearable device, therefore, has been developed that can project the construction drawings and related information on the basis of the needs of the users. This device is envisaged to help engineers avoid carrying bulky construction drawings to the site, and to reduce the effort required in looking for the correct drawings to obtain the information they need. This device includes four modules: the information-integration module, the display module, the positioning module, and the manipulation module. The information-integration module is used to transfer information in the building information model (BIM) into images to enable the on-site retrieval from the device that was developed. The position module enables users to input their locations and automatically search for the images that the users might need. The manipulation module can analyze the gestures of the users from the touch screen and accelerometer in the devices, and then crop the images to eliminate the unneeded information. The display module, which directly links to the projector, can continually calculate the images processed by the previous three modules and scale the images accordingly, ensuring that the projection results in a correct scale. A hardware device, coined the iHelmet, has also been developed to implement the four modules. It consists of a construction helmet (weight: 460 g), an iPod Touch (weight: 115 g), and an Optoma light-emitting diode (LED) projector (weight: 114 g). To validate the usability of the iHelmet on-site, a user test with 34 participants was conducted. A comparison of the efficiency and effectiveness of retrieving building information using the iHelmet was done using the traditional two-dimensional (2D) drawing approach. The results showed that the mean completion times were significantly shorter for participants using the iHelmet. The mean success rates of participants arriving at the correct answers were also significantly improved for those cases using the iHelmet.

Hardware settings of the iHelmet A small hole use for project information

A small frame to place iPod-Touch

a. A small holder frame and aperture on the outside of the helmet.

An acrylic sheet

An acrylic sheet

b. A platform and an acrylic sheet inside the helmet.

An electric wire

c. A data cable to connect the mobile device to the projector.

iHelmet Test of image quality from varied projected distances

a. testing ďŹ eld

1.5m

2.0m b. images projected from 1.5m, 2.0m and 2.5m

2.5m

Four control types for the manipulation module Control Type

Purpose

Description

Select a oor Tap right upper side

Single Tap

Tap right lower side

Select a view unit Tap and drag

Lock/Unlock the view unit Tap right upper side

Tap right lower side

Enter next view Slide from left to right

Slide Return to previous view

Slide from right to left

Double Tap

Obtain detailed information Double tap

Gesture control

Change vertical view range Look up

Look down

Shih-Chung Jessy Kang sckang@ntu.edu.tw sckang.caece.net