The Wiimote with Multiple Sensor Bars:

Creating an Affordable, Virtual Reality Controller

Torben Sko,

Henry Gardner,

School of Computer Science,

College of Engineering and Computer Science,

Canberra, ACT, 0200, Australia

Comments:

Manoj’s Blog

Franck’s Blog

Summary:

Introduction:

The attributes of the Wiimote are summarized along with the multi various applications to which it has been adapted. The paper focusses on extending the limited field of view of the IR camera by the use of multiple sensor bars so that the Wiimote can be used as a VR controller.

System:

1 Wiimote

5 Sensor bars

1 Nunchuk

The Wiimote has beeb modified into a gun with a grip, the Nunchuck is used in the left hand to move the character position.

A mode based reflex agent structure is used to track the position of the Wiimote. This includes a dynamic model of what it has seen and a static model of the layout of the sensor bars. At least two IR sources have to visible at all times and no more than four. When the system is initialized it aligns itself with the central sensor bar, that is to say the center of the static model. Moving from pair of sensor bars to another is performed by comparing models and discarding the one that is inconsistent. In this way errors in localization can be minimized. The system is also able to deal with the Wiimote loosing view of all sensor bars as long as the last one seen returns.

User Testing Setup:

A two wall back projection display system was used to evaluate performance. The VR Wiimote controller was integrated into a first person shooter game engine. A 3D real time cursor was also provided to give visual feedback.

Two games were used in the evaluation:

A custom built walk and explore game

half-Life 2

Evaluation:

12 users were tested all of which had had experience with games 8 of which with the Wii. They were given a simple explore and locate objects task, followed by a post test questionnaire. The purpose of this test was to determine if the sensor bar array was disturbing. None of the participants found it distracting, some even failed to notice it at all.

The next phase of the testing was to determine the usability of the setup. In particular, how frequently it would need resetting. Most users enjoyed the experience there were frustrations expressed with the controls. Additionally, some reported discomfort with the motion of the scenery.

Finally, after reducing the scenery rotation speed and moving the seat position further back. A subset of the users from the previous test with the highest reset rates were chosen. The new arrangement successfully reduced their error rates by 35%. Post testing the responses were more favorable finding the controller more natural.

Discussion:

Another interesting application of the Wiimote. An affordable VR theatre with a system of extending the field of view of the IR camera for position tracking. This will open up the Wiimote to many applications which before were not viable due to the narrowness of the field of view.

All that is needed now is for a way of increasing the range reducing the sensitivity to ambient light interference.