A Study of Eye Tracking as an Input Device for Immersive Environments.

This thesis presents the development of an eye tracking system for the control of cameras in real or virtual environments. Using an eye tracker allows an operator to control cameras from a ‘desktop’ virtual reality or robot control desk. Traditionally a handheld user interface device such as a joystick would be used to control the camera. By using the human eye as an input device the control of the camera is restored to the eye, leaving the hands free for a manipulation task. The eye tracker uses a rate driven approach to controlling cameras with a motorised pan and tilt capability. This generic control technique allows control of monoscopic or stereoscopic cameras on a robot, in a synthetically generated virtual environment, or in a mixed augmented reality setting. An eye tracker system has been developed and integrated with both a desktop virtual reality system, and a mobile robot with a high performance stereo head. A new approach to calibrating the commercial Vision Control Systems video based eye tracker has been implemented using machine vision techniques. The performance of this calibration technique is compared to three other methods for accuracy in relating the eye position to the gaze point on a computer screen. The performance of the calibrated eye tracker is then compared to a computer mouse and a head mounted display in a simulated environment. The results of these experiments provide a means to evaluate the combined performance of an operator and the input device. Finally some vehicle manoeuvring tasks were conducted using various user interface devices to ascertain different control modalities and the behaviour and performance of each. Control of the vehicle was provided by the joystick or eye tracker, and the stereoscopic robot head was variously fixed, or controlled by the head mounted display or eye tracker. In a like-with-like comparison with the head mounted display the vehicle manoeuvring task was completed marginally slower with the eye tracker. Control using the eye tracker is exercised from a computer workstation providing head mounted display like levels of control while the operator is able to interact with items in their local environment