Literature study: Wearable Control Room /LWHUDWXUHVWXG\FRQFHUQLQJZHDUDEOHFRPSXWHUVIRUXVHLQSURFHVVSODQWV This report is a literature study concerning different aspects of wearable computers. The report is meant to be used mainly as background information for defining relevant projects within the program “wearable control room” as well as an introduction of this research topics for Ph.D. students and other interested readers. ,QWURGXFWLRQ This report presents the state of the research concerning wearable computers with focus on use within process plants. In addition to wearable computers, the report focuses on human factors as well as the organisational and social aspects of substituting the existing centralised control room with distributed wearable computers. Research related to wearable computers has existed for several years, but most of the research has concentrated on other aspects and goals than developing a wearable control room for process plants. A wearable computer can generally be defined as (Bass 1997): • it may be used while the wearer is in motion; • it may be used while one or both hands are free or occupied with other tasks; • it exists within the corporeal envelope of the user, i.e., it should be not merely attached to the body but becomes an integral part of the person's clothing; • it must allow the user to maintain control; • it must exhibit constancy, in the sense that it should be constantly available. The following chapters outline the state of work related to different topics, applications and finally, universities and research institutions working with wearable computers. Chapter 2 pre- sents a short review of equipment available on the market. Chapter 3 continues with a review of different communication technologies used in wearable computing. This chapter is an exten- sion of chapter 3. In chapter 4, the integration of system components for information storage, support, training, etc. is presented. The next four chapters review different aspects of man- machine interaction. Chapter 5 focuses on the problems of visualisation; what should be visua- lised and how should it be visualised. Chapter 6 gives an introduction to cognitive science related to wearable computers. In chapter 7, literature concerning the human-human interac- tion, or the social aspects of wearable control rooms, is reviewed. The organisation structure may also be influenced by the introduction of distributed wearable control rooms and chapter 8 presents relevant references. The reviews of these topics are not necessarily related to wearable computers. However, expe- - 1 - Literature study: Wearable Control Room riences from, for example, mobile workplaces within consultancies may be transferred to pro- cess plants. After the chapters concerning particular topics, chapter 9 reviews different applications of interest. Finally, in chapter 10, relevant universities and research institutes working on subjects of interest for this work are presented. (TXLSPHQW A wearable computer system is equivalent to a typical desktop computer. However, it consists of a head mounted display or eyeglasses, input devices, wireless communication link to send or receive up-to-date information from remote servers, a wearable computer, a battery and optional user and environmental sensors. The physical characteristics such as weight and size are significant as the operator should be able to work without being disturbed by the wearable computer system (e.g., Columbia University, Birmingham University). This chapter reviews the trends within trackers and displays. The following chapter focuses on input devices. Whenever information is presented to human beings, it is important to present right informa- tion at right time. Especially, this is essential for augmented reality where computer-generated information is superimposed on transparent eye-glasses. Different types of trackers determine the positions of the user’s head and/or hands. Today, four types of trackers are used: (1) mag- netic trackers, (2) “WUHJKHWV´tracker, (3) optical trackers and (4) GPS. Magnetic trackers deter- mines a set of 3D coordinates based on magnetism, but these trackers are easily influenced by metal. The second category imitates the human vestibular sense system consisting of fine hair reacting on movements. These trackers are often inaccurate. The optical trackers are very pre- cise, but these are expensive. Finally, GPS is an accepted system for geographical positioning, but within small distances GPS is still too imprecise. The head mounted display or eyeglasses present visual information to the user. Today, different techniques are available and accepted for information presentation depending on the user’s tasks. Head mounted displays, or helmets, are mainly used to present 3D worlds that are detached from the reality and hence, its name “Virtual reality” (University of North Carolina). When the user moves his head the virtual landscape follows these movements. In virtual real- ity, the user can interact with the visualisation in different ways. In some systems, the virtual objects are overlaid with synthetical information (Carnegie Mellon University). A head mounted display can also consist of a single screen placed just above one of the user’s eyes. Hence, information that the user needs to perform a particular work task can be displayed on the screen (Chalmers University of Technology, Birmingham University). The user can see - 2 - Literature study: Wearable Control Room the reality as well as the information screen. Transparent eyeglasses has a different function compared to the two types of head mounted displays presented. Information is superimposed on the reality (e.g., Computer Graphics & User Interface Lab, Colorado School of Mines). This technique is called augmented reality. Today, it seems that augmented reality may perform some tasks that previous needed to be modelled in virtual reality. Examples are systems over- loaded by artificial information such as non-existing buildings and tag names in complex plants (Darmstadt University of Technology, MIT). Wearable computer systems using overlaid information require accurate trackers to determine the position of the user’s head and the syn- thetical information. Other problems are the resolution of the displays and graphic accelera- tors. However, a new type of visualisation called retinal scanners is just introduces (University of Washington). The virtual retinal display scans a low power beam of light which "paints" an image directly onto a user’s retina rather than a screen. Three laser sources (red, green, and blue) are combined to provide a full RGB color scale. These displays will see applications, not only in high end military and medical systems, but in aids for people with low vision and ulti- mately in everyday use with computers, telecommunications and television. 1DYLJDWLRQWHFKQRORJLHV(speech, touch pad, eye- and head tracking, etc.) Within a wearable computer system, different communication links exist between the user and the wearable computer (input device) as well as between the wearable computer and the remote server. This section focuses on communication from the user to the wearable computer system. Most of the wearable computer systems use speech recognition technology as the input device. Examples are the speech-driven wearable computer (manufactured by Speech Systems Inc.), wearable computers within the emergency service (e.g., Industrial Ergonomics Group at Bir- mingham University and West Yorkshire Ambulance Service) and the current prototype of the Factory Automation Support Technology (e.g., Georgia Tech Research Institute). Using voice activating input devices releases both hands of the user to perform other tasks. Other kinds of input devices are hand-held keyboards (alternatively put around an arm), mice and hand controls (sort of joystick). Head tracking is also used in some applications (surgery at RiT: the surgeon controls the direction of a camera within the patient by head movements (Austad and Pedersen 1996)). - 3 - Literature study: Wearable Control Room 6\VWHPLQWHJUDWLRQ(support system, information retrieval, CSCW, etc.) Electronic Performance Support System (EPSS): incorporates task specific information, train- ing and assistance at the worksite when most needed. Such systems include hypermedia, expert systems, computer assisted instruction and intelligent agents. The FAST framework is an extension of the EPSS in that FAST is a wearable EPSS. (Birmingham University) 9LVXDOLVDWLRQ(user interface; what should be presented and how should it be visualised) What should be visualised? How should it be visualised? (Feiner et al. 1993) The typical graphical user interface does not work with voice input. The older, command- based or function key-based user interface is much more effective. (Experiences from “A wearable computer for quality assurance inspectors in a food processing plant”). &RJQLWLYHVFLHQFHZLWKLQZHDUDEOHFRPSXWHUV Cognitive models are used to measure the human reliability, to predict and to understand actions taken by humans, to improve human-machine systems, etc. Best gives a general intro- duction to cognitive psychology (Best 1992). The following topics are of special interest for wearable control rooms: • work tasks performed by the operators • mental models • augmented reality The research on artificial intelligence and expert systems have combined computers and cogni- tion (Sheridan 1986). However, Newell and Simon’s model of human problem solving (Newell and Simon