Development of a reduced human user input task allocation method for multiple robots

Task allocation mechanisms are employed by multi-robot systems to efficiently distribute tasks between different robots. Currently, many task allocation methods rely on detailed expert knowledge to coordinate robots. However, it may not be feasible to dedicate an expert human user to a multi-robot system. Hence, a non-expert user may have to specify tasks to a team of robots in some situations. This paper presents a novel reduced human user input multi-robot task allocation technique that utilises Fuzzy Inference Systems (FISs). A two-stage primary and secondary task allocation process is employed to select a team of robots comprising manager and worker robots. A multi-robot mapping and exploration task is utilised as a model task to evaluate the task allocation process. Experiments show that primary task allocation is able to successfully identify and select manager robots. Similarly, secondary task allocation successfully identifies and selects worker robots. Both task allocation processes are also robust to parameter variation permitting intuitive selection of parameter values.     

An exploratory study: a measure of workload associated with teamwork

Team workload, which is usually described as an index of the ratio of available team resources to task demands, is believed to be critical for optimal human–computer integration. Although research conceptualizing team workload suggests that the measurement of team workload should consider workload unique to the team, the sum/min/max of members’ workload associated with taskwork referring to individual task performance is often used as an indicator of team workload. In order to better assess workload in team performance in which more than two individuals cooperate and conduct a task, it is also necessary to assess members’ workload associated with teamwork that refers to interpersonal interactions among individuals. The present study aims to develop a measure of workload associated with teamwork and discuss its contribution to operationalizing team workload. Results of team experiments indicate that the Teamwork Workload Scale is able to assess workload associated with teamwork and that it is necessary to assess both workload associated with taskwork and teamwork in order to better assess workload in team performance and operationalize team workload. In order to operationalize and measure team workload, it is necessary to investigate workload in team performance using quantitative data.     

Design of event-based PI-P controllers using interactive tools

In the field of event-based control, the tuning and synthesis of controllers represent a challenging task where the lack of specific computer-aided design tools makes very difficult the consolidation of emerging approaches. Under this scenario, it recently proposed the PI-P control strategy, a promising alternative which provides the designer with a practical design and an intuitive tuning methodology. This work addresses the design task of PI-P event-based controllers through the use of interactive tools. To this aim, first, a new interactive tool is provided. The tool is the result of implementing the theoretical developments of previous researches with the aim of consolidating the strategy. Second, the tool is used to analyze in detail the design paradigm through their main trade-offs between performance and robustness. The usefulness of analyses developed is experimentally demonstrated through several meaningful designs for typical industrial examples.     

Prospective memory while driving: comparison of time- and event-based intentions

Abstract

Prospective memories can divert attentional resources from ongoing activities. However, it is unclear whether these effects and the theoretical accounts that seek to explain them will generalise to a complex real-world task such as driving. Twenty-four participants drove two simulated routes while maintaining a fixed headway with a lead vehicle. Drivers were given either event-based (e.g. arriving at a filling station) or time-based errands (e.g. on-board clock shows 3:30). In contrast to the predominant view in the literature which suggests time-based tasks are more demanding, drivers given event-based errands showed greater difficulty in mirroring lead vehicle speed changes compared to the time-based group. Results suggest that common everyday secondary tasks, such as scouting the roadside for a bank, may have a detrimental impact on driving performance. The additional finding that this cost was only evident with the event-based task highlights a potential area of both theoretical and practical interest.

Practitioner Summary: Drivers were given either time- or event-based errands whilst engaged in a simulated drive. We examined the effect of errands on an ongoing vehicle follow task. In contrast to previous non-driving studies, event-based errands are more disruptive. Common everyday errands may have a detrimental impact on driving performance.     

A two-degree-of-freedom PI controller based on events

In this paper, a completely event-based two-degree-of-freedom proportional-integral controller is presented. The architecture of the controller is based on event-based decoupled solutions for the set-point following and the load disturbance rejection tasks. For the first task, the solution is a design procedure that, by considering a first-order-plus-dead-time model of the process and a predesigned open-loop control action, produces an event-based feedforward controller that provides the required process variable transition with just two events. The second task is solved by applying two separate event-based proportional and integral control actions. Because the two tasks are initially solved independently, two solutions for coupling them are described. Illustrative examples of the performance of the controller are included as well as experimental results.     

基于地域特征和异构社交关系的事件推荐算法研究

近几年,在基于事件的社交网络(EBSNs)服务中,为便于增强用户体验,事件推荐任务一直被广泛研究。本文基于对EBSN中用户行为数据的详细分析,提出了一种新型的融合多种数据特征的潜在因子模型。该模型综合考虑EBSN中两种新型的数据特征: 异构的社交关系特征(线上社交关系+线下社交关系)和用户参与行为的地域性特征。基于真实的Meetup数据集,实验结果表明我们的算法在解决事件推荐问题时比传统的算法有更好的性能。
     

Experimental procedure for measuring and comparing head–neck–trunk posture and movements caused by different progressive addition lens designs

This study demonstrates that appropriate measurement procedures can detect differences in head movement in a near reading task when using three different progressive addition lenses (PALs). The movements were measured using an anatomical reference system with a biomechanical rationale. This reference system was capable of representing rotations for comparing head flexion relative to trunk, head flexion relative to neck, head rotation relative to trunk and trunk flexion. The subject sample comprised 31 volunteers and three PAL designs with different viewing zones were selected. Significant differences were found between the lenses for three of the seven movement parameters examined. The differences occurred for both vertical and horizontal head movements and could be attributed to aspects of the PAL design. The measurement of the complete kinematic trunk–neck–head chain improved the number of differences that were found over those in previous studies.

Statement of Relevance: The study proposes a methodology based on a biomechanical rationale able to differentiate head–neck–trunk posture and movements caused by different progressive addition lens designs with minimum invasiveness. This methodology could also be applied to analyse the ergonomics of other devices that restrict the user's field of view, such as helmets, personal protective equipment or helmet-mounted displays for pilots. This analysis will allow designers to optimise designs offering higher comfort and performance.     

Metacognition and system usability: Incorporating metacognitive research paradigm into usability testing

There is an agreement that perceived usability is important beyond actual effectiveness of software systems. Perceived usability is often obtained by self-reports provided after system use. Aiming to improve summative usability testing, we propose a methodology to enhance in-depth testing of users' performance and perceived usability at the task level. The metacognitive research approach allows detailed analysis of cognitive processes. Adapting its methodologies, we propose the Metacognitive Usability Profile (MUP) which includes a comprehensive set of measures based on collecting confidence in the success of each particular task and triangulating it with objective measures. We demonstrate using the MUP by comparing two versions of a project management system. Based on a task analysis we allocated tasks that differ between the versions and let participants (N = 100) use both versions. Although no difference was found between the versions in system-level perceived usability, the detailed task-level analysis exposed many differences. In particular, overconfidence was associated with low performance, which suggests that user interfaces better avoid illusions of knowing. Overall, the study demonstrates how the MUP exposes challenges users face. This, in turn, allows choosing the better task implementation among the examined options and to focus attempts for usability improvement.     

Exercise and sports equipment: some ergonomics aspects

Sports equipment encompasses a gamut of devices used in laboratory, training and competitive contexts and these form the content of this paper. Ergometers range in sophistication from friction braked stationary bicycles to computer controlled simulators which incorporate exercise modes specific to the athletic user. These are now used in training, as experimental devices and in some instances for competition purposes. Training equipment exhibits a similar emphasis on exercise specificity, safety being an important aspect of its use. Design of projectiles for sporting activities has mainly reflected their traditional modes of use, the introduction of synthetic materials having some ergonomics implications. Similarly, materials science and design technology have contributed innovations in equipment for racquet sports and hitting implements. The changes have tended to be associated with availability of new materials for product construction and have implications for safety and skill in the transition to using the new products. Ski equipment design illustrates ergonomics factors in interfacing the performer with the sporting environment and how equipment has progressed by regenerative design processes. Enhancement of performance in some sports must be accompanied by an awareness of safety requirements: where appropriate, risks to participants should be reduced by use of protective clothing and equipment. Enforced validation of protective equipment is recommended to raise safety levels in certain sports and the safety of spectators must not be neglected. Human factors criteria can then be applied in monitoring, officiating and spectating at sporting events.     

The contingent effects of leadership on team collaboration in virtual teams

Decision-making in virtual teams creates challenges for leaders to structure team processes and provide task support. To help advance our knowledge of leadership in virtual teams, we explore the interaction effects between leadership styles and media richness on task cohesion and cooperative climate, which in turn influence team performance in decision-making tasks. Results from a laboratory study suggest that transactional leadership behaviors improve task cohesion of the team, whereas transformational leadership behaviors improve cooperative climate within the team which, in turn, improves task cohesion. However, these effects of leadership depend on media richness. Specifically, they occur only when media richness is low. Our results also suggest that task cohesion leads to group consensus and members’ satisfaction with the discussion, whereas cooperative climate improves discussion satisfaction and reduces time spent on the task.     

An empirical evaluation of textual display configurations for supervisory tasks

There is often a need to display logged information textually for real-time event-based supervisory tasks. Textual display design can follow several directions that reflect a tradeoff between a visual load and an operational load. The study reported here was designed in order to examine this tradeoff and its implications for such display design. An event-based monitoring and handling task was used with different event types having either a high or a low handling priority. The events were presented in four different display configurations varying in their degree of visual and operational load. The specific performance indices were event dwelling times, event handling proportion, and handling errors. In general it was found that the high priority events were handled faster and more accurately than the low priority events. In addition, performance with the various display configurations was dependent upon event type. These findings are discussed in terms of visual vs. operational load tradeoff and its context-sensitivity. Some implications for display design and further research on event presentation approaches are discussed.     

Simple Metrics for Improving Software Process Performance and Capability: A Case Study

This paper presents a case study which describes the application of statistical process performance monitoring and capability assessment on a large process control software project. The process performance and capability monitoring used in the case study is part of a Quality Framework for Software Development (QFSD) devised for the development of control systems at Fisher–Rosemount Systems and provides a practical alternative to ISO9000 quality models. The process performance measurements were based on commonly available metrics that could be obtained with the minimum disruption to the processes being examined. The application of statistical methods were used to establish problem areas at the earliest opportunity allowing process adjustments to be made to improve the process performance. The processes used were defined in terms of work products which were categorized and evaluated for the level of completion. This allowed a process capability to be calculated. Those processes which were found to be at a lower capability level became the focus for the process improvement for the next project. In particular the capability measurement identified processes where questions needed to be raised about the relevance of the process, whether the techniques used were effective and whether the tools were adequate. It was found that achieving high performance and capability is a learning process with the development team improving with each new project. The benefits have been better managed, more cost and time effective projects producing higher quality software. Management and the development team have obtained a better understanding of the software development process and this continuing learning process has lead to a continuous improvement in both the development methodology and the resulting software. The paper presents examples of the real benefits that can be obtained by tracking process performance and assessing process capability at all stages, and shows that this can be achieved without the need to resort to complex procedures for process measurement, as most of the empirical data came from commonly available process data.     

Information Alignment and Task Coordination in Organizations: An 'Information Clutch' Metaphor

Despite their rising popularity, distributed teams face a number of collaboration challenges that may potentially hinder their ability to productively coordinate their resources, activities, and information, often in dynamic and uncertain task environments. In this paper, we focus principally on the criticality of information alignment for supporting coordinated task performance in complex operational environments. As organizations become more expertise, geographically, and temporally distributed, appropriate alignment and coordination among distributed team members becomes more critical for minimizing the occurrence of information flow failures, poor decision-making, and degraded team performance. We first describe these coordination processes using the metaphor of an 'information clutch' that allows for smooth transitions of task priorities and activities in expert teams. We then present two case study examples that illustrate the potentially significant impact of information sharing and information alignment on productivity and coordination in organizations. We conclude with a discussion of future directions in this area.     

An empirical evaluation of textual display configurations for supervisory tasks

There is often a need to display logged information textually for real-time event-based supervisory tasks. Textual display design can follow several directions that reflect a tradeoff between a visual load and an operational load. The study reported here was designed in order to examine this tradeoff and its implications for such display design. An event-based monitoring and handling task was used with different event types having either a high or a low handling priority. The events were presented in four different display configurations varying in their degree of visual and operational load. The specific performance indices were event dwelling times, event handling proportion, and handling errors. In general it was found that the high priority events were handled faster and more accurately than the low priority events. In addition, performance with the various display configurations was dependent upon event type. These findings are discussed in terms of visual vs. operational load tradeoff and its context-sensitivity. Some implications for display design and further research on event presentation approaches are discussed.     

Uncovering the requirements of cognitive work

OBJECTIVE: In this article, the author provides an overview of cognitive analysis methods and how they can be used to inform system analysis and design. BACKGROUND: Human factors has seen a shift toward modeling and support of cognitively intensive work (e.g., military command and control, medical planning and decision making, supervisory control of automated systems). Cognitive task analysis and cognitive work analysis methods extend traditional task analysis techniques to uncover the knowledge and thought processes that underlie performance in cognitively complex settings. METHODS: The author reviews the multidisciplinary roots of cognitive analysis and the variety of cognitive task analysis and cognitive work analysis methods that have emerged. RESULTS: Cognitive analysis methods have been used successfully to guide system design, as well as development of function allocation, team structure, and training, so as to enhance performance and reduce the potential for error. CONCLUSIONS: A comprehensive characterization of cognitive work requires two mutually informing analyses: (a) examination of domain characteristics and constraints that define cognitive requirements and challenges and (b) examination of practitioner knowledge and strategies that underlie both expert and error-vulnerable performance. A variety of specific methods can be adapted to achieve these aims within the pragmatic constraints of particular projects. APPLICATION: Cognitive analysis methods can be used effectively to anticipate cognitive performance problems and specify ways to improve individual and team cognitive performance (be it through new forms of training, user interfaces, or decision aids).     

Information Alignment and Task Coordination in Organizations: An ‘Information Clutch’ Metaphor

Abstract

Despite their rising popularity, distributed teams face a number of collaboration challenges that may potentially hinder their ability to productively coordinate their resources, activities, and information, often in dynamic and uncertain task environments. In this paper, we focus principally on the criticality of information alignment for supporting coordinated task performance in complex operational environments. As organizations become more expertise, geographically, and temporally distributed, appropriate alignment and coordination among distributed team members becomes more critical for minimizing the occurrence of information flow failures, poor decision-making, and degraded team performance. We first describe these coordination processes using the metaphor of an ‘information clutch’ that allows for smooth transitions of task priorities and activities in expert teams. We then present two case study examples that illustrate the potentially significant impact of information sharing and information alignment on productivity and coordination in organizations. We conclude with a discussion of future directions in this area.     

Effects of Laptop Touchpad Texturing on User Performance

This research assessed user performance with different laptop touchpad textures. In specific, the study measured discrete movement task time and accuracy. It was hypothesized that texturing would increase task times but improve accuracy by providing users with tactile references. A variable representing the frictional potential of pads was introduced into an established model of discrete movement performance (Fitts’ Law) in an attempt to accurately model user performance under experimental task conditions. Results revealed touchpad texturing to degrade task performance. However, accuracy in pointing tasks was not significantly affected. Results also revealed that the expanded form of Fitts’ Law, including a parameter for representing the frictional potential of pad texturing, was more predictive of actual movement times than the original form of the Law. Results from the study increase understanding of the effects of touchpad texture on human motor control behavior and provide some guidance for future pad design.     

Additional helmet and pack loading reduce situational awareness during the establishment of marksmanship posture

Abstract

The pickup of visual information is critical for controlling movement and maintaining situational awareness in dangerous situations. Altered coordination while wearing protective equipment may impact the likelihood of injury or death. This investigation examined the consequences of load magnitude and distribution on situational awareness, segmental coordination and head gaze in several protective equipment ensembles. Twelve soldiers stepped down onto force plates and were instructed to quickly and accurately identify visual information while establishing marksmanship posture in protective equipment. Time to discriminate visual information was extended when additional pack and helmet loads were added, with the small increase in helmet load having the largest effect. Greater head-leading and in-phase trunk–head coordination were found with lighter pack loads, while trunk-leading coordination increased and head gaze dynamics were more disrupted in heavier pack loads. Additional armour load in the vest had no consequences for Time to discriminate, coordination or head dynamics. This suggests that the addition of head borne load be carefully considered when integrating new technology and that up-armouring does not necessarily have negative consequences for marksmanship performance.

Practitioner Summary: Understanding the trade-space between protection and reductions in task performance continue to challenge those developing personal protective equipment. These methods provide an approach that can help optimise equipment design and loading techniques by quantifying changes in task performance and the emergent coordination dynamics that underlie that performance.     

Examining the effects of communication training and teamcomposition on the decision making of Patriot air defense teams

An experiment investigating the effect of communication training and three group composition variables was performed with Patriot air defense teams for two different types of aircraft identification tasks. It was predicted that communication training would significantly enhance communication quantity and quality and, in turn, team performance for both tasks. Although the training did sometimes improve team communication processes, it did not improve team performance. The variable that had the biggest positive effect on communication quality and team performance was the number of hours a team had worked together. This effect was only found, however, for the type of task for which Patriot teams routinely train. It did not transfer to the less frequent and more cognitively stressing task where there is conflicting information about unknown aircraft, as in the USS Vincennes tragedy     

Multi-robot exploration under the constraints of wireless networking

A multi-robot system can be highly beneficial for exploration, which is a core robotics task. Application domains include, for example, surveillance, reconnaissance, planetary exploration or rescue missions. When using a team of robots, the overall performance can be much faster and more robust. In this article, an approach to multi-robot exploration is presented that takes the constraints of wireless networking into account. An algorithm is introduced based on a population that samples the possible moves of all robots and a utility to select the best one in each time step. Results from two scenarios are presented. In the first one, a team of robots explores its environment while permanently maintaining an ad hoc network structure with each other as well as a base station at a fixed location. In the second one, the robots move freely as a pack while maintaining communication with each other.