臺灣博碩士論文加值系統

Telerobot navigation requires human operators to have sufficient knowledge on remote situation, known as remote perception. Insufficient remote perception increases the risk of telerobot failures. The enhancement of remote perception often relates to the delivery of visual feedback in operator interfaces. Most of the recent works about operator interfaces adopted viewpoint tethering to improve situational awareness due to its exocentricity. A tethered viewpoint provides both global awareness and local guidance while visualizing remote situations. The tethered view, adhering to the line-of-sight requirement, potentialy delivers lower visual momentum when visualizing dense remote environment such as during indoor teleoperation tasks. This problem occurs as the tethered view, unlike the bird's-eye view, visualizes incomplete spatial information due to line-of-sight exclusion. Operators are thus strangled with the limited information while developing their spatial mental model, especially due to visual discontinuity that happens as the result of view transitions between robot's movements.

This dissertation presents an approach to improve the visual momentum of a tethered viewpoint display by complementing the omitted spatial information. The approach works by augmenting simplified spatial information on the excluded areas of a tethered view. The cues are used to illuminate the basic spatial structure and thus help to preserve the visual continuity on the views. The spatial cues further assist the operators in building their spatial mental models effectively by lowering their dependency on their naturally limited working memory. The tethered viewpoint displays are thus hypotheticaly posses higher visual momentum.

Evaluation of the presented approach was performed using V-REP simulator to simulate a telerobot environment that streams RGBD images, which is then reconstructed into 3D surface models and visualized in the tethered viewpoint displays. The evaluation involved eighteen voluntary participants to perform remote navigation tasks under different view configurations. The results suggested that applying cue augmentation in tethered viewpoint displyas resulted in a higher state of visual momentum. The heightened visual momentum was exhibited by the improvement of three common measures on operator performance. The improved measures include lowered average mental workload, the enhancement of both spatial perception and situational awareness. In particular, the lowered effort, frustration, and temporal demand provided the most influence to the lowered mental workload in average.

Telerobot navigation requires human operators to have sufficient knowledge on remote situation, known as remote perception. Insufficient remote perception increases the risk of telerobot failures. The enhancement of remote perception often relates to the delivery of visual feedback in operator interfaces. Most of the recent works about operator interfaces adopted viewpoint tethering to improve situational awareness due to its exocentricity. A tethered viewpoint provides both global awareness and local guidance while visualizing remote situations. The tethered view, adhering to the line-of-sight requirement, potentialy delivers lower visual momentum when visualizing dense remote environment such as during indoor teleoperation tasks. This problem occurs as the tethered view, unlike the bird's-eye view, visualizes incomplete spatial information due to line-of-sight exclusion. Operators are thus strangled with the limited information while developing their spatial mental model, especially due to visual discontinuity that happens as the result of view transitions between robot's movements.

This dissertation presents an approach to improve the visual momentum of a tethered viewpoint display by complementing the omitted spatial information. The approach works by augmenting simplified spatial information on the excluded areas of a tethered view. The cues are used to illuminate the basic spatial structure and thus help to preserve the visual continuity on the views. The spatial cues further assist the operators in building their spatial mental models effectively by lowering their dependency on their naturally limited working memory. The tethered viewpoint displays are thus hypotheticaly posses higher visual momentum.

Evaluation of the presented approach was performed using V-REP simulator to simulate a telerobot environment that streams RGBD images, which is then reconstructed into 3D surface models and visualized in the tethered viewpoint displays. The evaluation involved eighteen voluntary participants to perform remote navigation tasks under different view configurations. The results suggested that applying cue augmentation in tethered viewpoint displyas resulted in a higher state of visual momentum. The heightened visual momentum was exhibited by the improvement of three common measures on operator performance. The improved measures include lowered average mental workload, the enhancement of both spatial perception and situational awareness. In particular, the lowered effort, frustration, and temporal demand provided the most influence to the lowered mental workload in average.

Recommendation Letter i
Approval Letter ii
Abstract iii
Acknowledgements v
Contents vi
List of Figures x
List of Tables xiv
List of Algorithms xv
1 Introduction 1
1.1 Background and Motivation 1
1.2 Contribution 3
1.3 Organization 4
2 Related Work 5
2.1 Operator Interface 5
2.2 Benchmarking Operator Interface 7
3 Preliminaries 10
3.1 Telerobotics 10
3.2 Viewpoint Tethering 13
3.3 Visual Momentum 14
3.4 Spatial Mental Model 16
3.5 Pioneer 3DX Robot 17
3.6 V-REP Simulator 19
3.6.1 Functionalities 21
3.6.2 Usage in telerobot simulation 24
3.7 Simulated Omnidirectional RGBD Camera 27
3.8 OpenGL 33
3.9 NVIDIA CUDA 35
3.10 Latin-square Crossover Design 38
3.11 Estimation Reporting 39
3.12 NASA - Task Load Index 41
3.13 Situational Awareness Rating Technique 44
3.14 Spatial Situation Model Assessment 46
4 Tethered View with Spatial Cue Augmentation 48
4.1 Conceptual Overview 48
4.2 Architectural Overview 49
4.3 Model Alignment 50
4.4 Cue Definition 51
4.5 Back-face Removal 54
5 Experimental Platform 61
5.1 Simulated Telerobot Environment 61
5.2 Operator Interface 64
5.2.1 Display and Input Device 64
5.2.2 Surface Reconstruction from RGBD Images 67
6 Experiments and Results 74
6.1 Experiment Design 74
6.2 Experiment Procedure 75
6.3 Assessment Metrics 76
6.4 Results 82
6.4.1 Improved Spatial Perception and Awareness 82
6.4.2 Lower Operator Workloads 83
6.4.3 User Performance 85
6.4.4 Neccesity of Viewpoint Adjustment 86
6.4.5 Neccesity of Video Feedback 86
6.4.6 Better Spatial Comprehension 88
6.5 Discussion 90
6.5.1 Enhancement on Visual Momentum 90
6.5.2 LOS Ambiguity in Viewpoint Tethering 91
6.5.3 Outlier Responses 91
7 Conclusions 93
References 95
Appendix 1: Preliminary Response 102
Appendix 2: NASA-TLX Data 103
Appendix 3: SART Data 106
Appendix 4: SSM Data 107
Appendix 5: Attention Data 108
Appendix 6: Log File Data 109
Appendix 7: Final Response 110

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