Gaze Estimation Technique for Directing Assistive Robotics

AbstractAssistive robotics may extend capabilities for individuals with reduced mobility or dexterity. However, effective use of robotic agents typically requires the user to issue control commands in the form of speech, gesture, or text. Thus, for unskilled or impaired users, the need for a paradigm of intuitive Human-Robot Interaction (HRI) is prevalent. It can be inferred that the most productive interactions are those in which the assistive agent is able to ascertain the intention of the user. Also, to perform a task, the agent must know the user's area of attention in three-dimensional space. Eye gaze tracking can be used as a method to determine a specific Volume of Interest (VOI). However, gaze tracking has heretofore been under-utilized as a means of interaction and control in 3D space. This research aims to determine a practical volume of interest in which an individual's eyes are focused by combining past methods in order to achieve greater effectiveness. The proposed method makes use of eye vergence as a useful depth discriminant to generate a tool for improved robot path planning. This research investigates the accuracy of the Vector Intersection (VI) model when applied to a usably large workspace volume. A neural network is also used in tandem with the VI model to create a combined model. The output of the combined model is a VOI that can be used as an aid in a number of applications including robot path planning, entertainment, ubiquitous computing, and others

A Review and Analysis of Eye-Gaze Estimation Systems, Algorithms and Performance Evaluation Methods in Consumer Platforms

In this paper a review is presented of the research on eye gaze estimation techniques and applications, that has progressed in diverse ways over the past two decades. Several generic eye gaze use-cases are identified: desktop, TV, head-mounted, automotive and handheld devices. Analysis of the literature leads to the identification of several platform specific factors that influence gaze tracking accuracy. A key outcome from this review is the realization of a need to develop standardized methodologies for performance evaluation of gaze tracking systems and achieve consistency in their specification and comparative evaluation. To address this need, the concept of a methodological framework for practical evaluation of different gaze tracking systems is proposed.Comment: 25 pages, 13 figures, Accepted for publication in IEEE Access in July 201

Deformable Beamsplitters: Enhancing Perception with Wide Field of View, Varifocal Augmented Reality Displays

An augmented reality head-mounted display with full environmental awareness could present data in new ways and provide a new type of experience, allowing seamless transitions between real life and virtual content. However, creating a light-weight, optical see-through display providing both focus support and wide field of view remains a challenge. This dissertation describes a new dynamic optical element, the deformable beamsplitter, and its applications for wide field of view, varifocal, augmented reality displays. Deformable beamsplitters combine a traditional deformable membrane mirror and a beamsplitter into a single element, allowing reflected light to be manipulated by the deforming membrane mirror, while transmitted light remains unchanged. This research enables both single element optical design and correct focus while maintaining a wide field of view, as demonstrated by the description and analysis of two prototype hardware display systems which incorporate deformable beamsplitters. As a user changes the depth of their gaze when looking through these displays, the focus of virtual content can quickly be altered to match the real world by simply modulating air pressure in a chamber behind the deformable beamsplitter; thus ameliorating vergence–accommodation conflict. Two user studies verify the display prototypes’ capabilities and show the potential of the display in enhancing human performance at quickly perceiving visual stimuli. This work shows that near-eye displays built with deformable beamsplitters allow for simple optical designs that enable wide field of view and comfortable viewing experiences with the potential to enhance user perception.Doctor of Philosoph

Predictive Model of Driver\u27s Eye Fixation for Maneuver Prediction in the Design of Advanced Driving Assistance Systems

Over the last few years, Advanced Driver Assistance Systems (ADAS) have been shown to significantly reduce the number of vehicle accidents. Accord- ing to the National Highway Traffic Safety Administration (NHTSA), driver errors contribute to 94% of road collisions. This research aims to develop a predictive model of driver eye fixation by analyzing the driver eye and head information (cephalo-ocular) for maneuver prediction in an Advanced Driving Assistance System (ADAS). Several ADASs have been developed to help drivers to perform driving tasks in complex environments and many studies were conducted on improving automated systems. Some research has relied on the fact that the driver plays a crucial role in most driving scenarios, recognizing the driver’s role as the central element in ADASs. The way in which a driver monitors the surrounding environment is at least partially descriptive of the driver’s situation awareness. This thesis’s primary goal is the quantitative and qualitative analysis of driver behavior to determine the relationship between driver intent and actions. The RoadLab initiative provided an instrumented vehicle equipped with an on-board diagnostic system, an eye-gaze tracker, and a stereo vision system for the extraction of relevant features from the driver, the vehicle, and the environment. Several driver behavioral features are investigated to determine whether there is a relevant relation between the driver’s eye fixations and the prediction of driving maneuvers

Immersive Teleoperation of the Eye Gaze of Social Robots Assessing Gaze-Contingent Control of Vergence, Yaw and Pitch of Robotic Eyes

International audienceThis paper presents a new teleoperation system – called stereo gaze-contingent steering (SGCS) – able to seamlessly control the vergence, yaw and pitch of the eyes of a humanoid robot – here an iCub robot – from the actual gaze direction of a remote pilot. The video stream captured by the cameras embedded in the mobile eyes of the iCub are fed into an HTC Vive R Head-Mounted Display equipped with an SMI R binocular eye-tracker. The SGCS achieves the effective coupling between the eye-tracked gaze of the pilot and the robot's eye movements. SGCS both ensures a faithful reproduction of the pilot's eye movements – that is perquisite for the readability of the robot's gaze patterns by its interlocutor – and maintains the pilot's oculomotor visual clues – that avoids fatigue and sickness due to sensorimotor conflicts. We here assess the precision of this servo-control by asking several pilots to gaze towards known objects positioned in the remote environment. We demonstrate that we succeed in controlling vergence with similar precision as eyes' azimuth and elevation. This system opens the way for robot-mediated human interactions in the personal space, notably when objects in the shared working space are involved

Vehicular Instrumentation and Data Processing for the Study of Driver Intent

The primary goal of this thesis is to provide processed experimental data needed to determine whether driver intentionality and driving-related actions can be predicted from quantitative and qualitative analysis of driver behaviour. Towards this end, an instrumented experimental vehicle capable of recording several synchronized streams of data from the surroundings of the vehicle, the driver gaze with head pose and the vehicle state in a naturalistic driving environment was designed and developed. Several driving data sequences in both urban and rural environments were recorded with the instrumented vehicle. These sequences were automatically annotated for relevant artifacts such as lanes, vehicles and safely driveable areas within road lanes. A framework and associated algorithms required for cross-calibrating the gaze tracking system with the world coordinate system mounted on the outdoor stereo system was also designed and implemented, allowing the mapping of the driver gaze with the surrounding environment. This instrumentation is currently being used for the study of driver intent, geared towards the development of driver maneuver prediction models

Dynamic horizontal image translation in stereo 3D

Im Bereich Stereo 3D (S3D) bezeichnet „Dynamic Horizontal Image Translation (DHIT)“ das Prinzip, die S3D-Ansichten einer Szene horizontal in entgegengesetzte Richtungen zu verschieben, wodurch die dargestellte Szene in der Tiefe verschoben wird. Dies wird vor allem im Kontext von „Active Depth Cuts“ eingesetzt. Hier werden die S3D-Ansichten vor und nach einem Szenenschnitt so verschoben, dass es nicht zu starken, störenden Tiefensprüngen kommt. Die menschliche Wahrnehmung der DHIT wurde experimentell untersucht. Eine der wichtigsten Erkenntnisse war, dass es starke individuelle Unterschiede in der Empfindlichkeit gegenüber der DHIT gibt. Daher wird empfohlen die Verschiebungsgeschwindigkeit einer S3D-Ansicht nicht höher als 0,10 °/s bis 0,12 °/s zu wählen, sodass Zuschauerinnen und Zuschauer nicht von der DHIT gestört werden. Bei der DHIT kommt es zu einer Verzerrung der dargestellten Szenentiefe. Dies wird bei dem vorgeschlagenen Ansatz „Distortion-Free Dynamic Horizontal Image Translation (DHIT+)“ kompensiert, indem der Abstand zwischen den S3D-Kameras durch Verfahren der Ansichtensynthese angepasst wird. Dieser Ansatz zeigte sich signifikant weniger störend im Vergleich zur DHIT. Die Ansichten konnten ohne Wahrnehmungsbeeinträchtigung etwa 50% schneller verschoben werden. Ein weiteres vorgeschlagenes Verfahren ist „Gaze Adaptive Convergence in Stereo 3D Applications (GACS3D)“. Unter Verwendung eines Eyetrackers wird die Disparität des geschätzten Blickpunkts langsam über die DHIT reduziert. Dies soll die Ermüdung des visuellen Systems mindern, da die Diskrepanz zwischen Akkommodation und Konvergenz reduziert wird. In einem Experiment mit emuliertem Eye-Tracking war GACS3D signifikant weniger störend als eine normale DHIT. Im Vergleich zwischen dem kompletten GACS3D-Prototypen und einer Bildsequenz ohne jegliche Verschiebungen konnte jedoch kein signifikanter Effekt auf den subjektiven Betrachterkomfort registriert werden. Eine Langzeituntersuchung der Ermüdung des visuellen Systems ist nötig, was über den Rahmen dieser Dissertation hinausgeht. Da für GACS3D eine hochgenaue Schätzung der Blickpunktdisparität benötigt wird, wurde die „Probabilistic Visual Focus Disparity Estimation“ entwickelt. Bei diesem Ansatz wird die 3D-Szenenstruktur in Echtzeit geschätzt und dazu verwendet, die Schätzung der Blickpunktdisparität deutlich zu verbessern.Dynamic horizontal image translation (DHIT) denotes the act of dynamically shifting the stereo 3D (S3D) views of a scene in opposite directions so that the portrayed scene is moved along the depth axis. This technique is predominantly used in the context of active depth cuts, where the shifting occurs just before and after a shot cut in order to mitigate depth discontinuities that would otherwise induce visual fatigue. The perception of the DHIT was investigated in an experiment. An important finding was that there are strong individual differences in the sensitivity towards DHIT. It is therefore recommended to keep the shift speed applied to each S3D view in the range of 0.10 °/s to 0.12 °/s so that nobody in the audience gets annoyed by this approach. When a DHIT is performed, the presented scene depth is distorted, i.e., compressed or stretched. A distortion-free dynamic horizontal image translation (DHIT+) is proposed that mitigates these distortions by adjusting the distance between the S3D cameras through depth-image-based rendering techniques. This approach proved to be significantly less annoying. The views could be shifted about 50% faster without perceptual side effects. Another proposed approach is called gaze adaptive convergence in stereo 3D applications (GACS3D). An eye tracker is used to estimate the visual focus whose disparity is then slowly reduced using the DHIT. This is supposed to lessen visual fatigue since the infamous accommodation vergence discrepancy is reduced. GACS3D with emulated eye tracking proved to be significantly less annoying than a regular DHIT. In a comparison between the complete prototype and a static horizontal image translation, no significant effect on subjective visual discomfort could be observed, however. A long-term evaluation of visual fatigue is necessary, which is beyond the scope of this work. In GACS3D, highly accurate visual focus disparity is required. Therefore, the probabilistic visual focus disparity estimation (PVFDE) was developed, which utilizes a real-time estimation of the 3D scene structure to improve the accuracy by orders of magnitude compared to commonly used approaches

Ocular biomechanics modelling for visual fatigue assessment in virtual environments

The study objectively quantifies visual fatigue caused by immersion in virtual reality. Visual fatigue assessment is done through ocular biomechanics modelling and eye tracking to analyse eye movement and muscle forces into a visual fatigue index

Immersive Teleoperation of the Eye Gaze of Social Robots Assessing Gaze-Contingent Control of Vergence, Yaw and Pitch of Robotic Eyes

International audienceThis paper presents a new teleoperation system – called stereo gaze-contingent steering (SGCS) – able to seamlessly control the vergence, yaw and pitch of the eyes of a humanoid robot – here an iCub robot – from the actual gaze direction of a remote pilot. The video stream captured by the cameras embedded in the mobile eyes of the iCub are fed into an HTC Vive R Head-Mounted Display equipped with an SMI R binocular eye-tracker. The SGCS achieves the effective coupling between the eye-tracked gaze of the pilot and the robot's eye movements. SGCS both ensures a faithful reproduction of the pilot's eye movements – that is perquisite for the readability of the robot's gaze patterns by its interlocutor – and maintains the pilot's oculomotor visual clues – that avoids fatigue and sickness due to sensorimotor conflicts. We here assess the precision of this servo-control by asking several pilots to gaze towards known objects positioned in the remote environment. We demonstrate that we succeed in controlling vergence with similar precision as eyes' azimuth and elevation. This system opens the way for robot-mediated human interactions in the personal space, notably when objects in the shared working space are involved

Developing Predictive Models of Driver Behaviour for the Design of Advanced Driving Assistance Systems

World-wide injuries in vehicle accidents have been on the rise in recent years, mainly due to driver error. The main objective of this research is to develop a predictive system for driving maneuvers by analyzing the cognitive behavior (cephalo-ocular) and the driving behavior of the driver (how the vehicle is being driven). Advanced Driving Assistance Systems (ADAS) include different driving functions, such as vehicle parking, lane departure warning, blind spot detection, and so on. While much research has been performed on developing automated co-driver systems, little attention has been paid to the fact that the driver plays an important role in driving events. Therefore, it is crucial to monitor events and factors that directly concern the driver. As a goal, we perform a quantitative and qualitative analysis of driver behavior to find its relationship with driver intentionality and driving-related actions. We have designed and developed an instrumented vehicle (RoadLAB) that is able to record several synchronized streams of data, including the surrounding environment of the driver, vehicle functions and driver cephalo-ocular behavior, such as gaze/head information. We subsequently analyze and study the behavior of several drivers to find out if there is a meaningful relation between driver behavior and the next driving maneuver