Shared Control in Haptic Systems for Performance Enhancement and Training (original) (raw)

Haptic shared control improves tele-operated task performance towards performance in direct control

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 support system apply the required forces at the input (master) device. It is hypothesized that virtual forces from well-designed shared control will improve required time and accuracy, with less control effort, and that these benefits exist for perfect transparency but even more so for imperfect transparency. In an experimental study haptic shared control was designed to aid operators (n=9) with performing a simple bolt-spanner task using a planar (2D, 3DOF) tele-operator setup. Haptic shared control was compared to normal operation for three types of control: the baseline condition of direct control at the master (perfect transparency), teleoperation with a simple PERR controller, and a PERR controller with feedback gains set to zero (no transparency). The experimental results provided evidence for the hypotheses, showing that all tested tele-manipulation tasks benefit from haptic shared control, for all three levels of transparency. Essentially, the presence of haptic shared control allows for a worse transparency without compromising accuracy or required time, and can even improve accuracy and required time during perfect transparency. Subjective results indicated that the shared control was perceived as helpful and beneficial.

Progressive Shared Control for Training in Virtual Environments

2009

Virtual environments (VEs) with haptic feedback not only provide a safe and versatile practice medium for many manual control tasks, but also promise to improve the efficacy of manual skill training with the addition of haptic guidance. However, haptic guidance schemes such as shared control may be detrimental since such schemes actively interfere with the coupled system dynamics, thereby causing participants to experience task dynamics that are altered from those of the real task. Therefore, this paper proposes a progressive approach to guidance for training in virtual environments. This progressive guidance scheme adjusts its control gains based on participant performance, aiming to expose the performer to an appropriate amount of haptic guidance throughout training. Long term training experiments were conducted for an under-actuated target-hitting manual control task. The experimental results compare the efficacy of the novel progressive haptic guidance to two common fixed-gain haptic guidance schemes and virtual practice. The results from a month-long training experiment indicate that the proposed progressive shared control scheme reduces guidance interference as compared to fixed-gain guidance schemes thus increasing training efficacy.

A task-specific analysis of the benefit of haptic shared control during telemanipulation

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.

Negative efficacy of fixed gain error reducing shared control for training in virtual environments

ACM Transactions on Applied Perception, 2009

Virtual reality with haptic feedback provides a safe and versatile practice medium for many manual control tasks. Haptic guidance has been shown to improve performance of manual control tasks in virtual environments; however, the efficacy of haptic guidance for training in virtual environments has not been studied conclusively. This article presents experimental results that show negative efficacy of haptic guidance during training in virtual environments. The haptic guidance in this study is a fixed-gain error-reducing shared controller, with the control effort overlaid on the dynamics of the manual control task during training. Performance of the target-hitting manual control task in the absence of guidance is compared for three training protocols. One protocol contained no haptic guidance and represented virtual practice. Two protocols utilized haptic guidance, varying the duration of exposure to guidance during the training sessions. Exposure to the fixed-gain error-reducing sha...

Progressive haptic and visual guidance for training in a virtual dynamic task

2010

This paper presents the design and implementation of a novel progressive haptic guidance scheme and a similar visual guidance scheme for acquisition of a dynamic motor skill. The paper compares the schemes' performance to each other and to practice alone without any form of guidance. The target-hitting task is represented in a visual and haptic virtual environment and implemented in a training protocol that lasts eleven sessions over a two-month period. The progressive guidance controller employs as inputs two expertise-based performance measures, trajectory error and input frequency. The analysis of the experimental results demonstrates that while guidance is active, haptic guidance outperforms both visual guidance and practice alone (no guidance) until late in the protocol when all three groups saturate at the same level of performance. The results fail to show significant differences in training outcomes because the performance of all participants saturates toward the end of the protocol. The key implication of the experimental findings is that visual and haptic guidance presented in a progressive manner have no detrimental effects on performance. Our results confirm that haptic guidance, based on skill component measures, is effective early in the training protocol when participants are only beginning to understand the components of the task but should be progressively removed to avoid possible negative dependence on the guidance.

The Role of Haptic Communication In Shared Virtual Environments

1998

Investigating virtual environments has become an increasingly interesting research topic for engineers, computer and cognitive scientists, and psychologists. Although there have been several recent studies focused on the development of multimodal virtual environments (VEs) to study human-machine interactions, less attention has been paid to human-human and human-machine interactions in shared virtual environments (SVEs), and to our knowledge, no attention paid at all to what extent the addition of haptic communication between people would contribute to the shared experience. We have developed a multimodal shared virtual environment and performed a set of experiments with human subjects to study the role of haptic feedback in collaborative tasks and whether haptic communication through force feedback can facilitate a sense of being and collaborating with a remote partner. The study concerns a scenario where two participants at remote sites must cooperate to perform a joint task in an SVE. The goals of the study are (1) to assess the impact of force feedback on task performance, (2) to better understand the role of haptic communication in human-human interactions, (3) to study the impact of touch on the subjective sense of collaborating with a human as reported by the participants based on what they could see and feel, and (4) to investigate if gender, personality, or emotional experiences of users can affect haptic communication in SVEs. The outcomes of this research can have a powerful impact on the development of next-generation human-computer interfaces and network protocols that integrate touch and force feedback technology into the Internet, development of protocols and techniques for collaborative teleoperation such as hazardous material removal, space station

Active Manipulation of Users in Haptic-Enabled Virtual Environments

Proceedings of the First International Conference on Ambient Media and Systems, 2008

The main goal of this research is to study the effect of subthreshold forces on human performance in a haptic-enabled virtual reality system. A multi-modal task similar to Fitts is used to study the effects of the sub-threshold forces on user performance. Each user's movement is manipulated using controlled forces such that the user is not aware of the forces. Subjects can see the position of the haptic probe in a virtual environment where they are manipulated using sub-threshold forces. The multi-modal task is used to measure the accuracy of subjects in two experiments. During the experiments, the effects of force intensity and the relative direction of applied forces to the direction of user's hand motion in the presence of visual cues are investigated. A performance index is also introduced that can be used to evaluate human performance in the application of subthreshold forces. A psychophysical method is utilized to ensure that the applied forces on the user's hand are below the force threshold of the human haptic system. Results indicate that user performance is affected by both the intensity and direction of sub-threshold forces even when the users could control their actions through visual feedbacks.

Towards a Dual-User Haptic Training System User Feedback Setup

Lecture Notes in Computer Science, 2020

This paper introduces preliminary works on building an experimental end-user evaluation for dual-user haptic systems for hands-on training. Such systems bring together the advantages of haptic computerbased training systems and those of supervised training where an expert trainer actively helps in the learning process. The first results mainly permitted to highlight several technical and organizational issues to overcome in a close future. The objective of this project is to test other architectures such as those listed in the state-of-the-art section, to provide comparative conclusions about the pros and cons of each one.

Validation of a tuning method for haptic shared control using neuromuscular system analysis

2014 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2014

This research investigates a neuromuscular analysis based tuning procedure for haptic shared control systems that has been hypothesized to improve subjective operator workload when compared to heuristic tuning methods. Here, the tuning procedure takes into consideration the response of the neuromuscular system to haptic cues. Human arm stiffness, the neuromuscular property of concern, can be changed by modulating reflex strength. The 'relax task' setting of the neuromuscular system, for which reflexes are minimized, is chosen as the design point for tuning haptic cues as it is hypothesized to lead to the lowest workload. A simulated haptic collision avoidance system for unmanned aircraft teleoperation is used as a platform to experimentally validate the tuning method. The results show that the novel tuning procedure, particularly for relax task tuning, substantially improves workload and situational awareness over conditions that ignores the neuromuscular system. Additionally, over-tuning, which frequently occurs for heuristic methods, leads to worse user acceptance than a condition without haptic support.

Haptic Communication for a 2D Pointing Task in a Virtual Environment

Proceedings of the …, 2011

This paper examines the properties of haptic communication between two human operators using kinesthetic haptic devices in a collaborative task in a virtual environment. Twenty subjects, divided into 10 dyads, participated in a 2D pointing task. Each dyad consisted of a supervisor and an acting agent. The supervisor's role was to guide the acting agent towards a target in the virtual environment through either verbal or haptic communication only. Verbal communication was found to be the most efficient means of communication, but collaboration was also effective using haptic communication. Several different haptic communication strategies were observed, all with equal effectiveness as measured by task completion time. These strategies followed the same pattern as the verbal strategies. These results suggest that haptic communication in a virtual environment is possible, allowing for future designs of haptically enhanced collaborative work in virtual environments.