Telemanipulation allows human to perform operations in a remote environment, but performance and required time of tasks is negatively influenced when (haptic) feedback is limited. Improvement of transparency (reflected forces) is an important focus in literature, but despite significant progress, it is still imperfect, with many unresolved issues. An alternative approach to improve teleoperated tasks is presented in this study: Offering haptic shared control in which the operator is assisted by guiding forces applied at the master device. It is hypothesized that continuous intuitive interaction between operator and support system will improve required time and accuracy with less control effort, even for imperfect transparency. An experimental study was performed in a hard-contact task environment. The subjects were aided by the designed shared control to perform a simple bolt-spanner task using a planar three degree of freedom (DOF) teleoperator. Haptic shared control was compared to normal operation for three levels of transparency. The experimental results showed that haptic shared control improves task performance, control effort and operator cognitive workload for the overall bolt-spanner task, for all three transparency levels. Analyses per subtask showed that free air movement (FAM) benefits most from shared control in terms of time performance, and also shows improved accuracy.

In teleoperation, haptic feedback allows the human operator to touch the remote environment. Yet, it is only partially understood to what extent the quality of haptic feedback contributes to human-in-the-loop task performance. This paper presents a human factors experiment in which teleoperated task performance and control effort are assessed for a typical (dis-)assembly task in a hard-to-hard environment, well known to the operator. Subjects are provided with four levels of haptic feedback quality: no haptic feedback, low-frequency haptic feedback, combined low- and high-frequency haptic feedback, and the best possible-a natural spectrum of haptic feedback in a direct-controlled equivalent of the task. Four generalized fundamental subtasks are identified, namely: 1) free-space movement, 2) contact transition, 3) constrained translational, and 4) constrained rotational tasks. The results show that overall task performance and control effort are primarily improved by providing low-frequency haptic feedback (specifically by improvements in constrained translational and constrained rotational tasks), while further haptic feedback quality improvements yield only marginal performance increases and control effort decreases, even if a full natural spectrum of haptic feedback is provided.

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Haptic shared control is a promising approach to improve tele-manipulated task execution, by making safe and effective control actions tangible through guidance forces. In current research, these guidance forces are most often generated based on pre-generated, errorless models of the remote environment. Hence such guidance forces are exempt from the inaccuracies that can be expected in practical implementations. The goal of this research is to quantify the extent to which task execution is degraded by inaccuracies in the model on which haptic guidance forces are based. In a human-in-the-loop experiment, subjects (n = 14) performed a realistic tele-manipulated assembly task in a virtual environment. Operators were provided with various levels of haptic guidance, namely no haptic guidance (conventional tele-manipulation), haptic guidance without inaccuracies, and haptic guidance with translational inaccuracies (one large inaccuracy, in the order of magnitude of the task, and a second smaller inaccuracy). The quality of natural haptic feedback (i.e., haptic transparency) was varied between high and low to identify the operator's ability to detect and cope with inaccuracies in haptic guidance. The results indicate that haptic guidance is beneficial for task execution when no inaccuracies are present in the guidance. When inaccuracies are present, this may degrade task execution, depending on the magnitude and the direction of the inaccuracy. The effect of inaccuracies on overall task performance is dominated by effects found for the Constrained Translational Movement, due to its potential for jamming. No evidence was found that a higher quality of haptic transparency helps operators to detect and cope with inaccuracies in the haptic guidance.

PrefaceYou are about to read the results of the study I conducted in favour of my Master's thesis. This study was about haptic shared control in tele-manipulation. During this study I worked on the design and testing of a new haptic shared control application. I enjoyed working on this subject which is on the frontline of tele-manipulation research; until now most research focused on transparency to improve task performance, while this study shows that haptic shared control is a more effective approach. It was interesting to see how haptic shared control is able to bring together the inventiveness and complexity of human and the extensive possibilities of robotic devices.The various sides that were involved made this study nice to accomplish. One part of this study was the design of shared control and the adaption of the test setup, including the very practical aspects of implementing sensors and other hardware. Next to this, a human factor experiment was involved, which included the testing of subjects. Finally the measured data had to be processed and analyzed and a report had to be written.The focus of this study is a human factors experiment, which is described in detail in a research paper. The appendices provide background information and give a broad overview of the accomplished work. These appendices allow future students and researchers to gain detailed insight in the challenges faced during this study. The experimental setup is described in Appendix A. Appendix B shows the work done on modelling of the effects of shared control. Appendix C contains a description of the shared control design and implementation. The shared control experiment is described in Appendix D, including an extensive overview of the results. Appendix E contains a submitted conference paper, presenting a brief overview of the results. Finally, Appendix F shows some interesting insights gained during this research. An USB-stick containing used literature, software, raw measurement data and other information that could be of interest, was submitted to the Biomechanical Engineering depository and is available on request.I want to thank all people who contributed to this study. Special thanks to my coaches; David and Cock, thanks for all inspiring discussions and your efforts commenting and reviewing my work. Finally I want to thank my wife Juliët; thanks for your support especially during the last straws.Haptic shared control improves tele-operated task performance towards performance in direct control Abstract-In tele-operation, haptic feedback from the remote environment to the human is often limited, which has been shown to negatively influence the performance and required time of tasks. The conventional research focus is on improving the quality of the haptic feedback (transparency), which may have led to significant improvement, but is still imperfect, with many unresolved issues. The present study presents an alternative approach to improve tele-operated tasks: by offering haptic shared control in which both operator and suppor...