
\documentstyle[twocolumn]{article}
\pagestyle{empty}
\setlength{\textwidth}{6.9in}
\setlength{\textheight}{8.75in}
\setlength{\columnsep}{2.5pc}
\setlength{\topmargin}{-0.3in}
\setlength{\oddsidemargin}{-.3in}
\setlength{\parindent}{1pc}
\makeatletter
\def\@normalsize{\@setsize\normalsize{12pt}\xpt\@xpt \abovedisplayskip
11pt plus2pt minus5pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6pt plus3pt
minus3pt\let\@listi\@listI}
%the following line was changed
\def\subsize{\@setsize\subsize{12pt}\xipt\@xipt}
\def\section{\@startsection{section}{1}{\z@}{24pt plus 2 pt
minus 2 pt} {12pt plus 2pt minus 2pt}{\large\bf}}
\def\subsection{\@startsection {subsection}{2}{\z@}{12pt
plus 2pt minus 2pt}{12pt plus 2pt minus 2pt}{\subsize\bf}}
\makeatother

\input{psfig}

\begin{document}
\bibliographystyle{plain}
\date{}
\title{\Large\bf Surface Mine Truck Safety Training: \\ 
	Scenario Setup for a VR  Driving 
	Simulator\thanks{This work was partially supported by Newmont Gold Co., 
	Echo Bay Minerals, the Nevada Division of Industrial Relations, and the 
	Mine Safety Health Administration.}}

        \author{\begin{tabular}[t]{cc}
        Benjamin Lucchesi & Nerissa Oberlander \\
        \multicolumn{2}{c}{Department of Computer Science}   \\
        \end{tabular}
\\
\\
\begin{tabular}[t]{cc}
Frederick C. Harris, Jr.        & Pierre Mousset-Jones \\
Department of Computer Science  & Department of Mining Engineering\\
fredh@cs.unr.edu                & mousset@mines.unr.edu\\
\\
\multicolumn{2}{c}{University of Nevada}\\
\multicolumn{2}{c}{Reno, NV~~ 89557}\\
\end{tabular}}


\maketitle
\thispagestyle{empty}

\vspace{1in}

%\begin{abstract}
\subsection*{\centering Abstract}
\vspace*{-3mm}

	In the surface mining industry, the cost of workplace accidents
	is high, and traditional safety training methods for equipment
	operators are costly and time consuming.  This paper outlines the
	motivation for and development of a Scenario Setup application
	for a virtual reality based simulator known as the Mine Vehicle
	Driving Simulator (MVDS), which can cut costs and improve mine
	safety. It further discusses implementation issues,
	attempts to draw conclusions, and outlines possible
	future work.  
%\end{abstract}


\section{Introduction.}


        Workplace accidents in the mining industry reduce production,
        increase costs, and result in debilitating injuries 
        or death to mine workers.  Accidents are a major
        concern in day-to-day mining operations, where they can be
        expensive in terms of both cost and employee morale.

        One of the most effective tools used to prevent on-the-job 
	accidents is worker training.  However, the cost of accident prevention
        training is high, particularly when the method attempts to
        provide a realistic representation of risks associated with
        mining vehicle operation and the proper  techniques that avoid or
        manage those risks.  Preparing  video demonstrations, conducting
        safety training tours of work sites, and on-site safety
        briefings are all effective training tools. But these methods are
        disruptive to daily operations and expensive.  As a general
        rule, the more realistic a training exercise, the more expensive.

	Virtual reality (VR) technology based training tools
	offer an excellent approach to reducing both job accidents
	and the high cost of training.	The Mine Vehicle Driving Simulator
	(MVDS) developed at the University of Nevada is an example of
	such a VR training tool.  It provides a cost-effective simulation
	of mine vehicle operation.  As a simulation, MVDS provides the
	opportunity for realistic, flexible mine vehicle safety training at a
	substantial reduction in cost.

	This paper provides a brief overview of the challenges facing the
	surface mining industry with particular reference to off-highway
	mining vehicles that are typically used in this type of mining.
	It discusses the industry trend to explore new techniques, such
	as MVDS, for training workers and preventing accidents.  It then
	describes the goals and technology that underlie the MVDS Setup
	(MVDSS) and provides an overview of its capabilities.  Finally,
	the effectiveness of MVDSS and its future potential is discussed.


\section{Surface Mining.}\label{sec:openpit}

	The United States Occupational Safety and Health Administration
	(OSHA) stated in 1995 that industrial trucks are the second
	leading cause of fatalities in the private sector, second
	only to highway vehicle fatalities~\cite{OSHA95}. On average,
	there are 107 fatalities involving industrial trucks and
	38,330 injuries annually in the work place.  The Mine Safety
	and Health Administration (MSHA) reports that over the last
	few years accidents involving operators of off-highway vehicles,
	an example of which is shown in Figure~\ref{fig:cat785}, in
	surface ground mining operations have resulted in between 15 and
	20 fatalities per year and between 350 and 450 near fatalities per
	year~\cite{MSHA98}.  Present training standards appear ineffective
	in reducing the number of accidents involving off-highway vehicles.
	OSHA and MSHA both have been revising standards to increase
	their effectiveness by requiring initial and followup training.

\begin {figure}[h]
   %\centerline{\psfig{figure=truck.ps,width=8cm}}
   \centerline{\psfig{figure=truck-fixed.ps,width=8cm}}
   \caption{An Off-Highway Mining Vehicle.}
   \label{fig:cat785}
\end{figure}

	Only trained and authorized employees can operate off-highway
	vehicles.  The amount and type of training provided  is dealt
	with on an employee by employee basis and is directly
	related to the operator's ability to acquire the skills 
	necessary to safely operate the vehicle.  A periodic evaluation
	of each  operator's performance is required. Followup or remedial
	training is required, based primarily on incidents of unsafe
	operation, an accident or near miss, or deficiencies found in
	a routine periodic evaluation of the operator.

	General attitudes towards industrial safety, environmental
	concerns, and industrial design have advanced significantly
	in recent years, and the mining industry has advanced in this
	direction.  The introduction of new safety and environmental
	legislation throughout the world has changed the emphasis of
	industrial law from prescriptive legislation to the adoption of
	more effective management systems.  Many mining companies have
	responded to these new ideas and initiated the introduction
	of modern management philosophies~\cite{staley92:cscatsim}.
	A range of new techniques have been applied to meet new
	legislative and production requirements.

	Large mining organizations are now looking for ways to improve
	their performance by utilizing new technologies.  Rapid
	advances in computer graphics and VR provide a very ``real''
	way to describe complex ideas. By applying VR technologies to
	training, mining companies are able to convey the risks
	involved in various job roles.	This type of training is much
	more understandable by the operator than books, videos, and
	seminars. This enhanced understanding has been extensively
	discussed by a number of authors.


\section{VR Technologies.}


	The value of virtual reality is that it can offer experiences
	that would otherwise be inaccessible to an individual, because
	such situations might be too expensive, too dangerous, occur
	at the wrong time, or in the wrong location.  VR training can
	give the individual experience beyond training methods currently
	in use.  One of the most successful examples of a VR application
	is commercial aircraft flight simulation.  This extremely
	expensive implementation of VR provides a very realistic setting
	for pilot training that includes all of the sights, sounds,
	control motions, and physical movement associated with flying
	aircraft.

	Hardware and software used to implement VR applications have
	improved dramatically over the last few years.	High-end 
	PC-class workstations, with the addition of a 3D accelerated video
	card, have the potential to support VR applications which were
	once restricted to expensive hardware-specific applications.
	In addition, a number of peripheral hardware devices, such as
	VR goggles, gloves, 3D sound, and motion tracking systems are
	designed to heighten the user's sense of reality and increase
	training effectiveness.  Furthermore, software vendors are
	marketing a range of packages for developing VR applications.

	As noted by Foley, van Dam, et al. \cite{fvdfhp97:itcg}
	``Interactive graphics is a field whose time has come.''
	Software Application Programming Interfaces (APIs) that draw
	geometric objects for developing graphically intensive software
	are becoming standardized.  One such low level API is OpenGL.
	The challenge of using a low level graphics API for developing
	software is that the application developer must make a substantial
	effort to create even the simplest 3D object.  To reduce
	the complexity of developing graphically intensive software,
	toolkits built on top of low level graphics APIs are used.
	These toolkits focus development on user interaction and scene
	management rather than drawing objects.

	One method of implementing this type of high-level toolkit
	utilizes scene graph technology (SGT).	Scene objects such as
	cameras, lights, and geometry allow the programmer to concentrate
	on scene composition. Examples of APIs that implement SGT
	include Open Inventor, Java3D, and Fahrenheit.	In addition,
	these packages are windowing system and platform independent.


\section{Mine Vehicle Driving Simulator.}

	The first project our group developed was the Mine Vehicle
	Driving Simulator (MVDS).  MVDS simulates driving mine vehicles
	in an open-pit surface mine. One of the project specifications
	dictated that the simulation be usable on high-end PC-class
	workstations.  MVDS was designed using the Open Inventor 
	API~\cite{openinventor}.  We chose the Open Inventor API because
	it incorporates a powerful and flexible implementation of scene
	graph technology.

	In order to accommodate a variety of mine terrain  formats, we
	have designed utilities for MVDS to process and output the data
	to an Open Inventor compatible file format.  We currently have
	several utilities to process mine terrain data files.  Support for
	additional terrain formats can be added by implementing a utility
	to convert these to the Open Inventor compatible file format.

	One of the main goals of MVDS is to allow the trainers to observe
	the reactions of new vehicle operators without having to be
	in the vehicles with them while they are learning to drive.
	This will give the trainers a better idea of how the trainees
	will react to the hazards in the mine.  MVDS also allows 
	trainees to get the basic feel for how the vehicles will react
	before they actually step inside the real vehicle.  With different
	weather conditions that can be simulated in a mine, operators
	will have a fairly good idea of how these vehicles will react
	during less than ideal conditions.  

\section{Scenario Setup for MVDS.}

	Once a prototype of MVDS was completed the trainers that
	used it asked whether training scenarios could be added.
	The additions that were recommended can be organized into two
	categories. The first category relates to adhering to specific
	operation regulations, particularly when you interact with other
	moving	and stationary vehicles.  These ``rules of the road''
	for mine vehicle operators differ considerably from Department
	of Motor Vehicle regulations for highway vehicles. For example,
	in most mines, operators are required to drive on the left rather
	than the right side of the road.  The second category of additions
	they recommended relates to the physical operation of the mine
	vehicle.  This will teach the trainees how the vehicle ``feels''
	on the road.  The trainee  will have to deal with the effects of
	having wet, icy, or muddy roads; how the slope of the haul road
	effects acceleration and breaking; and how other environmental
	conditions, such as fog, will effect driving in the mine.

	In addition to the rules of the road, MVDS can be used to teach
	the trainee the layout of the mine, such as the location of the
	loader, dump site, and other important landmarks.  In order to
	do this, the location of these things in the scenario can be
	changed  as the mine itself changes.

\begin {figure}
   \centerline{\psfig{figure=mvdss-view.ps,width=8cm}}
   \caption{Setting up a scenario with MVDSS.}
   \label{fig:trainer-interface}
\end{figure}

	The MVDS Setup program (MVDSS), shown in
	Figure~\ref{fig:trainer-interface}, will allow on-site trainers
	to make new scenarios for trainees to navigate as the mine and
	operating regulations change.  The trainers will be able to change
	the entire feel of the mine by moving shovels, loaders, and closing
	routes the trainee may have used in the past.  With this kind
	of flexibility for configuring the mine, a trainer can test the
	trainee's ability to handle situations that can occur in the mine.

	When designing a scenario, objects added by the trainer fall into
	two classifications, static and dynamic hazards.  A static hazard may
	be something like a traffic cone used to close off an area of
	the operation, or a surveyor's truck parked on the side of the
	road.  A dynamic hazard could be another mine vehicle operating
	in the mine.  When placing a hazard, the  trainer selects a
	location in the mine, and a hazard to go there.  If the trainer
	is placing a dynamic hazard, the location is a path (or series
	of locations) the hazard will follow at a pre-defined speed.
	With these hazards in place, regulations relating to static
	and dynamic hazards can be reviewed, since regulations vary
	depending on the type of hazard.  Any object that is modeled in
	an Open Inventor compatible file format can be added as a static or
	dynamic hazard.  We currently provide cones, people, pick-ups,
	loaders, and other vehicles.

        The second category of training provided by MVDS provides the
        trainee with a feel for the physical operation of the vehicles.
        Off-highway mine vehicles are significantly different 
	than passenger vehicles or highway trucks that the trainee might have
        previously driven.  Furthermore, there is a considerable
        difference in the behavior of these vehicles in their loaded and
        unloaded states. Training that gives trainees
        a feel for handling these vehicles can be of great value.
        MVDS currently supports gearing, breaking, steering, and the
        general handling characteristics of the mining vehicles.

	MVDSS can be used to configure the vehicle state (such as load),
	weather, and haul road conditions.  The trainer can keep the
	hazards the same, but change the type of whether conditions
	that are present in the mine or change the load that the vehicle
	is carrying.  By doing this the trainer will be able to see how
	well the trainee will be able to react to the different types
	of driving conditions.

	Once a scenario is fully configured, this information can be
	saved to a file which is used by MVDS.	Scenarios can also be
	re-loaded and modified to reflect changes in the mine and MSHA
	regulations over time.	This gives trainers the flexibility to
	build a library of scenarios used to test the skills of vehicle
	operators.

\section{Conclusions and Future Work.}

	Although virtual reality simulators are not new, employing such
	simulators to reduce training costs and reduce accident rates
	is relatively new to the mining industry.  Some of our previous work
	dealing with pre-operational vehicle inspection, the Mine Vehicle
	Inspection Simulator (MVIS)~\cite{MVIS}, has shown that the
	industry is quite willing to expand their training into new
	technological areas.  Response to MVIS and prototypes of MVDS
	have generated strong interest in development of more training
	tools of this type.


	Future improvements to MVDS include a broader variety of hazards
	to challenge the trainee. For example dynamic scenery, such as
	rock slides, will allow the trainer to evaluate the trainees
	response to a broader range of unexpected situations. Our
	current implementation of MVDS supports one vehicle operator. A
	distributed version of MVDS would allow  multiple vehicle operators to
	interact with each other in the same simulation. It is reasonable
	to imagine the equivalent of a complete surface mining operation
	within a single simulation, with many trainees concurrently
	engaged in their specific assignments and interacting with
	each other.

	With these and other improvements to MVDS, such as sound, the
	MVDSS would help provide safety trainers with a wide variety of
	possibilities to effectively train new hires in the
	correct and safe operation of mining vehicles.
        
\parskip=0pt
\itemsep=0pt
\bibliography{/staff/fredh/papers/bibdir/vr}
\end{document}
