Automation-induced complacency for monitoring highly reliable systems: the role of task complexity,system experience,and operator trust

The increase in quantity and complexity of advanced automated systems has generated new concerns surrounding automation-induced complacency, or the difficulties operators have monitoring the status of automated systems. The present investigation consists of two studies that assessed the impact of system reliability, monitoring complexity, operator trust, and system experience on automation-induced complacency. In both studies, participants operated a manually controlled flight task while monitoring several simulated aircraft displays for failures. The ability of operators to detect a single automation failure over three experimental sessions was also assessed. Results indicated that realistic levels of system reliability severely impaired an operator's ability to monitor effectively. Further, as system experience increased, operator monitoring performance declined. The results also indicated that the complexity of the monitoring task heavily influenced operator monitoring, with poorer performance associated with more cognitively demanding tasks. Finally, results from both studies indicated that operator trust increased and monitoring performance decreased as a function of increasing system reliability. These results suggest that for highly reliable systems, increasing task complexity and extensive experience may severely impair an operator's ability to monitor for unanticipated system states.     

A design condition for incorporating human judgement into monitoring systems

In safety monitoring, there exists an uncertainty situation in which the sensor cannot detect whether or not the monitored object is in danger. For the uncertainty zone identified by a non-homogeneous safety monitoring system that utilizes two types of sensors with different thresholds, operators or experts are expected to judge whether the real state is safe or dangerous on the basis of additional information from a detailed inspection or other related sensors output. However, the activities for inspection performed by relevant humans may require additional cost and introduce inspection errors. The present article proposes two types of an automatic monitoring system not involving any human inspection or a human–machine (H–M) cooperative monitoring system with inspection. In order to compare the systems, an approach based on the Dempster–Shafer theory is proposed as uncertainty analysis by this theory (it is simpler than by the traditional Bayesian approach). By comparing their expected losses as a result of failed dangerous failures or failed safe failures as well as the inspection errors, the condition is determined under which H–M cooperative systems incorporating human judgements are more effective than automatic monitoring systems.     

On the representation of automation using a work domain analysis

Work domain analysis (WDA) has been applied extensively within cognitive engineering as an analytic framework for the evaluation of complex sociotechnical systems in support of design. However, the WDAs described in the literature have not explored the representation of automated system components, despite the documented problems associated with operator-automation interaction and the requirements for operator support in complex automated systems. The current research examines the application of WDA to model an example automated system – a camera – by representing the camera along with its automated components as separate systems using the abstraction hierarchy (AH). Additionally, we contrasted this modelling approach with the more typical approach of modelling automation within a cognitive work analysis (CWA) by performing a control task analysis using the decision ladder. The results of these analyses suggest that, similar to non-automated systems, considering a separate representation of an automated system within the WDA may provide useful system design guidance in terms of user support and information requirements. The comparison of the AH and the decision ladder (DL) models indicates that the models provide different information about the requirements and support different user needs: the AH provides information about specific subsystems and components of the automation that are used for control and how they support functions and purposes of the automation while the DL shows how the control tasks are achieved interleaving automated actions with those of the user. The information obtained from modelling automation with the AH is different from what would normally be obtained by performing only a control task analysis, yet is necessary for operator support.     

Similarities and differences between human–human and human–automation trust: an integrative review

The trust placed in diagnostic aids by the human operator is a critical psychological factor that influences operator reliance on automation. Studies examining the nature of human interaction with automation have revealed that users have a propensity to apply norms of human–human inter-personal interaction to their interaction with ‘intelligent machines’. Nevertheless, there exist subtle differences in the manner in which humans perceive and react to automated aids compared to human team-mates. In the present paper, the concept of trust in human–automation dyads is compared and contrasted with that of human–human dyads. A theoretical framework that synthesizes and describes the process of trust development in humans vs automated aids is proposed and implications for the design of decision aids are provided. Potential implications of this research include the improved design of decision support systems by incorporating features into automated aids that elicit operator responses mirroring responses in human–human inter-personal interaction. Such interventions will likely facilitate better quantification and prediction of human responses to automation, while improving the quality of human interaction with non-human team-mates.     

Two-moment approximations for analysing a series of automated workstations

In this research we develop two-moment approximation equations for the analysis of a series of automated workstations with infinite buffer capacity. An automated workstation is a server with deterministic processing times that experiences random operating times between failures, and then subsequent random repair times. The distribution of job inter-departure times from a workstation receiving input from an automated workstation is derived. From this distribution, expressions for the mean and variance of job inter-departure times from a workstation are obtained. These are then used as a basis for ‘linking’ workstations in a two-workstation aggregation approach. This method is compared to modelling such a system as a series of G/G/1 queues. The analysis method is easily implemented in a spreadsheet. Extensive computational experiments demonstrate the effectiveness of the overall approach.     

A framework for the analysis of cognitive reliability in complex systems: a recovery centred approach

Managing complex industrial systems requires reliable performance of cognitive tasks undertaken by operating crews. The infrequent practice of cognitive skills and the reliance on operator performance for novel situations raised cognitive reliability into an urgent and essential aspect in system design and risk analysis. The aim of this article is to contribute to the development of methods for the analysis of cognitive tasks in complex man-machine interactions. A practical framework is proposed for analysing cognitive errors and enhancing error recovery through interface design. Cognitive errors are viewed as failures in problem solving which are difficult to recover under the task constrains imposed by complex systems. In this sense, the interaction between context and cognition, on the one hand, and the process of error recovery, on the other hand, become the focal points of the proposed framework which is illustrated in an analysis of a simulated emergency.     

A Novel Miniature Four-Dimensional Force/Torque Sensor With Overload Protection Mechanism

Force sensors play a key role in modern technology. Specifically, they can measure the force of mechatronics systems used in automated manufacturing environments, thereby enabling such systems to function effectively, thus facilitating decision making. However, the most current generation of force and torque sensors is complicated and expensive. Moreover, these sensors cannot be used for many applications because they are too brittle to sustain a large load. Accordingly, this paper presents a novel miniature four-dimensional force sensor, whose element is in the form of an E-type membrane connected to double rectangle slices. This sensor is aimed at obtaining the accurate interaction forces, including the normal force, both tangential force terms and the torque about the normal axis, in most applications. Furthermore, the sensor contains the advantages of configuration simplicity, overload protection and high sensitivity. Experiment results demonstrate its strong linearity, weak couplings among dimensions and simple calibration. The maximum nonlinearity errors is 0.18% F.S. and the maximum interference errors is 1.9% F.S.      

Carbon Nanotube Yarn for Fiber-Shaped Electrical Sensors,Actuators, and Energy Storage for Smart Systems

Smart systems are those that display autonomous or collaborative functionalities, and include the ability to sense multiple inputs, to respond with appropriate operations, and to control a given situation. In certain circumstances, it is also of great interest to retain flexible, stretchable, portable, wearable, and/or implantable attributes in smart electronic systems. Among the promising candidate smart materials, carbon nanotubes (CNTs) exhibit excellent electrical and mechanical properties, and structurally fabricated CNT-based fibers and yarns with coil and twist further introduce flexible and stretchable properties. A number of notable studies have demonstrated various functions of CNT yarns, including sensors, actuators, and energy storage. In particular, CNT yarns can operate as flexible electronic sensors and electrodes to monitor strain, temperature, ionic concentration, and the concentration of target biomolecules. Moreover, a twisted CNT yarn enables strong torsional actuation, and coiled CNT yarns generate large tensile strokes as an artificial muscle. Furthermore, the reversible actuation of CNT yarns can be used as an energy harvester and, when combined with a CNT supercapacitor, has promoted the next-generation of energy storage systems. Here, progressive advances of CNT yarns in electrical sensing, actuation, and energy storage are reported, and the future challenges in smart electronic systems considered.     

Promising perspectives towards regrowing a human arm

Despite the great enthusiasm about tissue engineering during the 1980s and the many significant basic observations made since then, the clinical application of tissue-engineered products has been limited. However, the prospect of creating new human tissues and organs is still exciting and continues to be a significant challenge for scientists and clinicians. A human arm is an extremely complicated biological construction. Considering regrowing a human arm requires asking about the current state-of-the-art of tissue engineering and the real capabilities that it may offer within a realistic time horizon. This work briefly addresses the state-of-the-art in the fields of cells and scaffolds that have high regenerative potential. Additional tools that are required to reconstruct more complex parts of the body, such as a human arm, seem achievable with the already available more sophisticated culture systems including three-dimensional organization, dynamic conditions and co-cultures. Finally, we present results on cell differentiation and cell and tissue maturation in culture when cells are exposed to mechanical forces. We postulate that in the foreseeable future even such complicated structures such as a human arm will be regrown in full in vitro under the conditions of a mechanically controlled co-culture system.     

Automated multiple failure FMEA

Failure mode and effects analysis (FMEA) is typically performed by a team of engineers working together. In general, they will only consider single point failures in a system. Consideration of all possible combinations of failures is impractical for all but the simplest example systems. Even if the task of producing the FMEA report for the full multiple failure scenario were automated, it would still be impractical for the engineers to read, understand and act on all of the results.This paper shows how approximate failure rates for components can be used to select the most likely combinations of failures for automated investigation using simulation. The important information can be automatically identified from the resulting report, making it practical for engineers to study and act on the results. The strategy described in the paper has been applied to a range of electrical subsystems, and the results have confirmed that the strategy described here works well for realistically complex systems.     

The DYLAM approach for the dynamic reliability analysis of systems

In many real systems, failures occurring to the components, control failures and human interventions often interact with the physical system evolution in such a way that a simple reliability analysis, de-coupled from process dynamics, is very difficult or even impossible. In the last ten years many dynamic reliability approaches have been proposed to properly assess the reliability of these systems characterized by dynamic interactions. The DYLAM methodology, now implemented in its latest version, DYLAM-3, offers a powerful tool for integrating deterministic and failure events. This paper describes the main features of the DYLAM-3 code with reference to the classic fault-tree and event-tree techniques. Some aspects connected to the practical problems underlying dynamic event-trees are also discussed. A simple system, already analyzed with other dynamic methods is used as a reference for the numerical applications. The same system is also studied with a time-dependent fault-tree approach in order to show some features of dynamic methods vs classical techniques. Examples including stochastic failures, without and with repair, failures on demand and time dependent failure rates give an extensive overview of DYLAM-3 capabilities.     

State of the art in sensor technologies for sewer inspection

This paper reviews the state of the art in sensors and automated inspection devices for enhanced sewer inspection. Efficiency, safety, environmental, and legislative concerns have made inspection and assessment of communal sewers a central issue to water and sewerage companies. Nowadays, the standard sewer inspection system is based on a wheeled platform on which a closed circuit television (CCTV) camera is mounted. One of the disadvantages of camera inspection systems is that they can only detect a small proportion of all possible damage in a sewer. The inspection outcome of such systems relies not only on the quality of the acquired images, but also on the off-line. recognition and classification conducted by human operators. In consequence, CCTV-based platforms are frequently not effective. Infrared, microwave, optical, and ultrasonic-based sensors have been proposed to complement the existing CCTV-based approach and to improve inspection results. New inspection devices employing multiple sensors and being capable of carrying out remote sewer inspection tasks are under research     

The storage complex considered as a system component

To permit further growth in the application of information systems, the lower level activities must be automated so that they cease to be a burden on the user. A synthesis of known hardware devices and software algorithms for dynamic storage allocation is advocated which can achieve acceptable efficiency at run time by using the explicitly defined data structure as a basis for store management and the prediction of store usage. The resultant automated storage complex also provides security against the propagation of consequential software failures. Consideration of the function of the individual storage devices which would be components of such a storage complex leads to some conclusions which may be useful for guiding the development of advanced storage devices.     

Towards more reliable automated multi-dose dispensing: retrospective follow-up study on medication dose errors and product defects

To date, little is known on applicability of different types of pharmaceutical dosage forms in an automated high-speed multi-dose dispensing process. The purpose of the present study was to identify and further investigate various process-induced and/or product-related limitations associated with multi-dose dispensing process. The rates of product defects and dose dispensing errors in automated multi-dose dispensing were retrospectively investigated during a 6-months follow-up period. The study was based on the analysis of process data of totally nine automated high-speed multi-dose dispensing systems. Special attention was paid to the dependence of multi-dose dispensing errors/product defects and pharmaceutical tablet properties (such as shape, dimensions, weight, scored lines, coatings, etc.) to profile the most suitable forms of tablets for automated dose dispensing systems. The relationship between the risk of errors in dose dispensing and tablet characteristics were visualized by creating a principal component analysis (PCA) model for the outcome of dispensed tablets. The two most common process-induced failures identified in the multi-dose dispensing are predisposal of tablet defects and unexpected product transitions in the medication cassette (dose dispensing error). The tablet defects are product-dependent failures, while the tablet transitions are dependent on automated multi-dose dispensing systems used. The occurrence of tablet defects is approximately twice as common as tablet transitions. Optimal tablet preparation for the high-speed multi-dose dispensing would be a round-shaped, relatively small/middle-sized, film-coated tablet without any scored line. Commercial tablet products can be profiled and classified based on their suitability to a high-speed multi-dose dispensing process.     

Stabilization of structurally damped systems by time-delayed feedback control

A time delay occurs in the application of feedback-type controls to flexible structures due to the finite response time of sensors and actuators. This, in turn, may destabilize the system as a result of the time lag between the information and the actuation. The present study investigates the stabilization of damped structural systems by velocity feedback control when there is a time delay in applying the control. The conditions under which the system remains stable are derived and the asymptotic stablity is studied. It is shown that the velocity feedback increases the rate of decay of the system energy. Interrelation of various problem parameters are numerically investigated by considering some numerical examples of structurally damped beams     

Determination of human error patterns: The use of published results of official enquiries into system failures

Official enquiries into large scale system failures may be used to interpret events according to the various types of human error which were committed. For example there are errors in operation of the system, in maintenance practices etc. Twelve well documented disasters are analysed and the conclusion emerges that operator error predominates. This fact is not suprising, reflecting as it does the short time span in which operators have to make decisions, compared to the other players such as designers, maintenance men etc. This conclusion has implications for the other human disciplines involved. For example designers should conceive systems which will be less prone to operator error, while management should support operators in whatever way possible to increase their effectiveness.     

Fault-tolerant spacecraft attitude control system

Spacecraft perform a variety of useful tasks in our day-to-day life. These are such that spacecraft need to function properly without interruptions for 7 to 15 years in space without any maintenance. Though most spacecraft have redundant systems to serve as back-ups in case of failures, they greatly depend on human assistance through ground stations for failure analysis, remedial actions and redundancy management, resulting in itnerruption in services rendered. There is, therefore, need for a fault-tolerant system that functions despite failures and takes remedial action, without human assistance/intervention, autonomously on board the spacecraft. Commonly used techniques for fault-tolerance in computers cannot be directly used for fault-tolerance in sensors and actuators of a closed loop control system. Further, for space applications fault-tolerance needs to be achieved without much penalty in weight and computational requirements. This paper describes briefly the attitude control system (acs) of a spacecraft and highlights the essential features of a fault-tolerant control system. Schemes for fault tolerance in sensors and actuators are presented with an analysis on various failure modes and their effects. Newly developed fault-detection, identification and reconfiguration (fdir) algorithms for various elements ofacs are described in detail. Also an optimum symmetrically skewed configuration for the attitude reference system using dynamically tuned gyros is developed. Some of the schemes have already been used in Indian Spacecraft. As future Indian space missions will directly cater to various applications on an operational basis, the ultimate objective is to have a totally fault-tolerant ‘intelligent’ autonomous spacecraft.     

Model-based approach to the detection and classification of mines in sidescan sonar

This paper presents a model-based approach to mine detection and classification by use of sidescan sonar. Advances in autonomous underwater vehicle technology have increased the interest in automatic target recognition systems in an effort to automate a process that is currently carried out by a human operator. Current automated systems generally require training and thus produce poor results when the test data set is different from the training set. This has led to research into unsupervised systems, which are able to cope with the large variability in conditions and terrains seen in sidescan imagery. The system presented in this paper first detects possible minelike objects using a Markov random field model, which operates well on noisy images, such as sidescan, and allows a priori information to be included through the use of priors. The highlight and shadow regions of the object are then extracted with a cooperating statistical snake, which assumes these regions are statistically separate from the background. Finally, a classification decision is made using Dempster-Shafer theory, where the extracted features are compared with synthetic realizations generated with a sidescan sonar simulator model. Results for the entire process are shown on real sidescan sonar data. Similarities between the sidescan sonar and synthetic aperture radar (SAR) imaging processes ensure that the approach outlined here could be made applied to SAR image analysis.     

Disposable hydrophobic surface on MALDI targets for enhancing MS and MS/MS data of peptides

Automated analyses in MALDI MS are complicated by the uneven distribution of analyte over the sample spot, resulting in areas of analyte localization, or "sweet spots". Hence, the ability to concentrate and localize samples is advantageous, especially for automated studies involving low concentrations of analyte. A method for rapidly creating a removable and affordable hydrophobic surface that is free from memory effect is presented. The potential for such compounds to serve as a practical coating for MALDI targets is examined. An example compound with a complete methodology is shown to increase sample homogeneity, peak intensity, and resolution when used for peptide mixtures with CHCA and DHB.