Thomas B. Sheridan

A model for types and levels of human interaction with automation

Technical developments in computer hardware and software now make it possible to introduce automation into virtually all aspects of human-machine systems. Given these technical capabilities, which system functions should be automated and to what extent? We outline a model for types and levels of automation that provides a framework and an objective basis for making such choices. Appropriate selection is important because automation does not merely supplant but changes human activity and can impose new coordination demands on the human operator. We propose that automation can be applied to four broad classes of functions: 1) information acquisition; 2) information analysis; 3) decision and action selection; and 4) action implementation. Within each of these types, automation can be applied across a continuum of levels from low to high, i.e., from fully manual to fully automatic. A particular system can involve automation of all four types at different levels. The human performance consequences of particular types and levels of automation constitute primary evaluative criteria for automation design using our model. Secondary evaluative criteria include automation reliability and the costs of decision/action consequences, among others. Examples of recommended types and levels of automation are provided to illustrate the application of the model to automation design.

Space teleoperation through time delay: review and prognosis

A 30-year history of research on dealing with the effects of time delay in the control loop on human teleoperation in space is reviewed. Experiments on the effects of delay on human performance are discussed, along with demonstrations of predictive displays to help the human overcome the delay. Supervisory control is shown to offer a variety of options, from switching to local impedance control upon contact with the environment to higher-level local automation. Wave transformation techniques to ameliorate the effects of delay are also described. Space teleoperations have tended to deal with the problem of time delay by avoiding it and not attempting to teleoperate from the ground. It is suggested that the US space effort might have gotten further ahead and at a lower cost with a greater is commitment to space teleoperation from the ground through the delay. Predictive display works well for free positioning. Local impedance control is recommended for control in contact with the environment, possibly accompanied by wave transformation techniques. Higher level supervisory control is always an option for sufficiently predictable tasks and will continue to improve with better sensors and task models. >

Robust compliant motion for manipulators, part I: The fundamental concepts of compliant motion

A method for the design of controllers of constrained manipulators in the presence of model uncertainties is developed. The controller must carry out fine maneuvers when the manipulator is not constrained, and compliant motion, with or without interaction-force measurement, when the manipulator is constrained. At the same time stability must be preserved if bounded uncertainties are allowed in modelling the manipulators. Stability of the manipulator and environment as a whole and the preservation of stability in the face of changes are two fundamental issues that have been considered in the design method. A set of practical design specifications in the frequency domain is presented that is meaningful from the standpoint of control theory and assures the desired compliant motion in the Cartesian coordinate frame and stability in the presence of bounded uncertainties. This approach also assures the global stability of the manipulator and its environment. The consequence of inexact achievement of performance specifications on stability is also specified. Part I concerns the fundamentals of compliant motion, while Part II is devoted to the controller design method.

Supervisory control of remote manipulation

The relatively short distances to be spanned in using the manipulators presently available permit real-time control systems, frequently employing direct linkages. The advent of space flight necessitates the design of manipulation systems that can perform complicated tasks, on the moon and beyond, upon command from earth. Such a design must compensate for the communications time delay due to the distances involved and also for a difference in environment not directly observable by the human operator. The answer to the problem seems to lie in a computer-controlled remote unit, capable of making limited decisions of its own but supervised from home base.

Situation Awareness, Mental Workload, and Trust in Automation: Viable, Empirically Supported Cognitive Engineering Constructs

Cognitive engineering needs viable constructs and principles to promote better understanding and prediction of human performance in complex systems. Three human cognition and performance constructs that have been the subjects of much attention in research and practice over the past three decades are situation awareness (SA), mental workload, and trust in automation. Recently, Dekker and Woods (2002) and Dekker and Hollnagel (2004; henceforth DWH) argued that these constructs represent “folk models” without strong empirical foundations and lacking scientific status. We counter this view by presenting a brief description of the large science base of empirical studies on these constructs. We show that the constructs can be operationalized using behavioral, physiological, and subjective measures, supplemented by computational modeling, but that the constructs are also distinct from human performance. DWH also caricatured as “abracadabra” a framework suggested by us to address the problem of the design of automated systems (Parasuraman, Sheridan, & Wickens, 2000). We point to several factual and conceptual errors in their description of our approach. Finally, we rebut DWHs view that SA, mental workload, and trust represent folk concepts that are not falsifiable. We conclude that SA, mental workload, and trust are viable constructs that are valuable in understanding and predicting human-system performance in complex systems.

Human-automation interaction

Automation does not mean humans are replaced; quite the opposite. Increasingly, humans are asked to interact with automation in complex and typically large-scale systems, including aircraft and air traffic control, nuclear power, manufacturing plants, military systems, homes, and hospitals. This is not an easy or error-free task for either the system designer or the human operator/automation supervisor, especially as computer technology becomes ever more sophisticated. This review outlines recent research and challenges in the area, including taxonomies and qualitative models of human-automation interaction; descriptions of automation-related accidents and studies of adaptive automation; and social, political, and ethical issues. Keywords: Driver distraction; Language: en

Remote Manipulative Control with Transmission Delay

The nature of remote manipulation is briefly discussed and several manipulator devices are described. The problem of manipulation with delay is considered, and an experiment to determine the effect of delay on completion time for a simple manipulative task is reported. It appears that under certain circumstances the time required with delay can be predictd from performance measures which are independent of delay.

Design issues in 2-port network models of bilateral remote manipulation

A two-port impedance-network model of a single-degree-of-freedom remote manipulation system in which a human operator at the master port interacts with a task object at the slave port in a remote location is presented. The design of the network involves the selection of feedback gains for the servomechanisms that transmit motion and force information from one port of the two-port to the other in both directions. The proposed methodology allows this selection to be based on both stability requirements and specifications of desired port impedances, given models of the task and the human operator. The resulting design guidelines guarantee stability for any passive task object at the slave port and any passive human impedance at the master port.<<ETX>>

Teleoperation, telerobotics and telepresence: A progress report

Abstract This paper briefly surveys and reports progress in the field of teleoperation, meaning human control of remote sensors and actuators. Included is the subclass of teleoperation called telerobotics, which means human supervisory control of remote semiautomatic systems, and the phenomenon of telepresence, in which special sensing and display technology enables the human to feel present at the remote location even though not really there. Current and new applications are reviewed. Techniques for human-computer cooperation in planning, commanding, and sensing are described. The telerobot is considered as a paradigm for any complex vehicle or process having many separate automatic control loops all of which are supervised by a human; some current examples are presented. Finally, opinions are given as to the current status of the field.

Three Models of Preview Control

This paper discusses a means to describe and eventually to predict the response of a human or artificially intelligent controller which 1) has a constrained preview of the actual input course and which 2) observes the successive target values as being of nonuniform importance. Three examples are: driving an automobile in traffic, a blind pedestrian using a cane or electronic obstacle detector, and remote manipulation of solid objects using artificial sensors and effectors. Three models are presented which characterize constrained preview control better than can conventional transfer function techniques.