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\title
%{Virtual Reality Surface Mine Simulator\thanks{This 
{Surface Mine Truck Safety Training with VR\thanks{This 
work 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]{c@{\extracolsep{8em}}c}
	\author{\begin{tabular}[t]{ccc}
	Denis Cote 	&  Damien Ennis 	& Benjamin Lucchesi \\
	Nerissa Oberlander & 			&Keith Wesolowski \\
	\multicolumn{3}{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}

\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 an
	alternative training method, a VR-based simulator known as the
	Mine Vehicle Safety Simulator (MVSS), which can cut costs and
	improve mine safety. It further discusses implementation issues
	including the trainer and trainee interfaces, attempts to draw
	conclusions about the effectiveness of the MVSS with respect to
	traditional training methods, and outlines possible future
	work.

{\bf keywords:} Surface Mining, Safety Training, Virtual Reality

\section{Introduction.}

	\hspace*{1em}
	Workplace accidents in the mining industry reduce production,
	increase costs, and result in temporary and permanent
	disabilities and even death to mine workers.  They are always a
	major concern in day-to-day mining operations, where accidents
	can be expensive in terms of both cost and employee morale.

	One of the most important tools for on-the-job accident
	prevention is worker training.  However, the cost of accident
	prevention training is quite high, particularly when the
	training attempts to provide a realistic and compelling image
	of the risks that are associated with mining and the proper
	techniques for avoiding or managing those risks.  Preparing
	video demonstrations, conducting safety training tours of work
	sites, and conducting on-site safety briefings can all be
	effective training tools, but each can be expensive and even
	disruptive to daily operations.  As a general rule, the more
	realistic a training exercise, the more expensive.

	Virtual reality technology offers an excellent approach to
	reducing both job accident rates and the high cost of
	training.  The Mine Vehicle Safety Simulator (MVSS) developed
	at the University of  Nevada is an example of such a virtual
	reality tool.  It provides a cost-effective simulation of mine
	vehicle operation. As a simulation, MVSS provides the
	opportunity for realistic, flexible mine safety training at a
	substantial reduction in cost.

	This paper provides a brief overview of the
	accident prevention challenge facing the surface mining
	industry with particular reference to off-highway haulage trucks
	that are typically used in this type of mining.
	It discusses the industry trend to explore
	new techniques for training workers and preventing accidents,
	describes the goals, concepts, and technology that
	underlie MVSS and provides an overview of its capabilities and
	operational modes.  Finally, the effectiveness of
	MVSS as a training tool and its future potential is discussed.

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

	\hspace*{1em}
	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. 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 trucks, such as the CAT 785
	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 to be somewhat ineffective in reducing
	the number of accidents involving off-highway trucks.
	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,height=2.5in}}
   \centerline{\psfig{figure=truck.ps,width=8cm}}
   \caption{A Cat 785.}
   \label{fig:cat785}
\end{figure}

	Only trained operators who are specifically authorized to do so
	can operate off-highway trucks.  The amount and type of
	training provided  is dealt with on an individual basis.  This
	training will be directly related to the operator's ability to
	acquire the skills that are necessary to safely operate the
	truck.  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 not been an
	exception.

	The introduction of new safety and environmental legislation
	throughout the world has changed the emphasis of industrial law
	from prescriptive legislation toward 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 the new legislative and
	production requirements.

	Large mining organizations are now looking for ways to improve
	their performance, including new technologies.  The rapid
	advances in computer graphics and Virtual Reality provide a
	very ``real'' way through which complex ideas and information
	can be conveyed to a work force or to the general public.
	These new techniques allow videos, simulators, and planning
	systems to be developed quickly, efficiently, and relatively
	inexpensively. A typical individual's ability to remember
	information gained from an interactive three-dimensional computer
	environment is far greater than his or her ability to translate
	information from a printed page into the real world.
	This enhanced understanding has been extensively
	discussed by a number of authors.

	MVSS is example of how such virtual reality technology can be
	adapted to the needs of a specific industry.


\section{Implementation of MVSS.}\label{sec:mvss}

	\hspace*{1em}
	The project specifications dictated that the simulation be
	useable on MS Win 9X/NT systems, as the sponsoring companies
	primarily use Windows-based PC's for their information
	systems.  MVSS was designed using the Open Inventor Graphics
	API~\cite{openinventor}.  The Open Inventor API had a 
	number of advantages for the
	project. It is powerful and flexible while having a reasonable
	learning curve, which leads to a remarkably rapid development
	time.

	The mine vehicle safety simulator can accept multiple graphic
	file formats for input of mine terrain data. Currently
	supported formats include Surpac and a variety of
	proprietary formats. This flexibility is accomplished through a
	set of utilities, one for each file format supported, which
	process and output the mine data to a common file format.  
	MVSS can then read this common file format.
	Support for additional terrain formats can be added by 
	implementing a utility to convert to a common file format.

	MVSS can provide a variety of training exercises for the
	vehicle operator.  The experiences that are provided for the
	operator can be organized into two categories. The first
	category is experiences relating to the process of adhering to
	specific mine vehicle operation regulations.  These so-called
	``rules of the road'' for mine vehicle operators differ
	considerably from Department of Motor Vehicle regulations for
	regular highway vehicles, the rules most people including new
	mine vehicle operators, are familiar with.  For example, in
	most mines, mine vehicle operators are required to drive on the
	left rather than the right side of the road.  The
	second category relates to the physical operation of the mine
	vehicle.

	MVSS provides a rich variety of simulation scenarios for 
	operator regulations. The operator can be exercised and tested
	in basic procedure adherence, responding to static hazards, and
	responding to dynamic hazards (involving other moving
	objects).  Any combination of rules and conditions can be set
	up through MVSS, with the most basic scenario being an exercise
	in driving on the proper side of the road in the mine setting.
	The interface for setting these options is shown in Figure 2.
	Another simple scenario can monitor whether the trainee adheres
	to correct speed limits in the mine, such as the 25-mph maximum
	speed limit. At the opposite extreme, a more challenging
	scenario could involve requiring that the trainee respond to
	multiple moving vehicles behaving in an irregular manner.

\begin {figure}[h]
   \centerline{\psfig{figure=hazard_placement.ps,width=8cm}}
   \caption{Setting up the Simulation.}
   \label{fig:trainer-interface}
\end{figure}

	MVSS can also be used to teach the trainee the layout of the
	mine, such as the location of the loader, dumpsite, and other
	important landmarks.  Regulations relating to static hazards
	can be introduced. These are regulations, unique to surface
	mines, regarding vehicle operation in the proximity of static
	objects, with the regulations varying depending on the type of
	object.  The static objects that can be presented to the
	trainee by MVSS include cones, persons, pick-ups, loaders,
	and other trucks.  
	One scenario might involve placing a
	pick-up in the vicinity of a loader, such that the pick-up is
	a nuisance to loading operations. The trainee could then be
	tasked with safely carrying out loading operations under the
	increased stress.

	The most challenging scenarios MVSS can present to trainees 
	include dynamic hazards such as persons, pick-ups, 
	loaders, and other trucks.  A typical scenario
	could involve the trainee approaching a loading zone with a moving
	pick-up added to complicate the process.  As with any
	of the simulations, the trainee's response to the situation can
	be scored. The most extreme scenarios could involve the trainee
	responding to single or multiple moving vehicles behaving
	irregularly or dangerously.  An example would include a pick-up
	that sneaks behind the trainee's truck, positioned to
	cause an accident should the trainee ignore any of the required
	procedures for safely reversing his or her truck.
	An example a situation a trainee is faced with is shown in 
	Figure 3. 

\begin {figure}[h]
   \centerline{\psfig{figure=driving.ps,width=8cm}}
   \caption{Another hauling truck to avoid.}
   \label{fig:truck-hazard}
\end{figure}

	The second category of training provided by MVSS provides the
	trainee with a feel for the physical operation of the truck.
	The actual Caterpillar trucks operated by the trainees can weigh
	up to  170 tons empty and 460 tons when fully loaded with
	rock. Obviously, these trucks behave and respond very
	differently from any passenger vehicle or even highway trucks
	that the trainee might have previously encountered.
	Furthermore, there is a considerable difference in the behavior
	of these trucks in their loaded and unloaded states. Therefore,
	experiences that give trainees a feel for handling these
	vehicles can be of great value.  MVSS currently supports
	gearing, breaking, steering and the general handling
	characteristics of the Caterpillar trucks.  But MVSS is unable
	to provide the feel of slipping when an unloaded vehicle
	accelerates or de-accelerates too rapidly.

	Another training dimension provided by MVSS includes allowing
	trainees to respond to equipment malfunctions.  The graphical
	display of the cab, dashboard and gauges is modeled to have the
	same appearance as the actual layout in the Caterpillar trucks.
	MVSS can test the trainee by displaying these gauges showing
	malfunctions such as low oil, high engine temperature, low
	battery power, and other mechanical problems.

	After completing the simulation, the trainees will receive
	their performance results. These results are in the form of a
	text file. The results file details the trainee's performance
	during the simulation.  In addition, immediate feedback is
	given when a catastrophic event such as a collision occurs. 

\section{Conclusions \& Future Work}\label{sec:conclusions}

	\hspace*{1em}
	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.  Presenting hard
	statistics on current costs, in addition to well-founded
	predictions of cost savings incurred by the use of virtual
	reality simulators, will help attract interest from the mining
	industry.  In addition, many mining professionals are probably
	not aware of what is possible with the current state of virtual
	reality technology. Therefore, participation in industry
	conferences to demonstrate current technology should help the
	use of simulators, such as MVSS, gain mining industry
	acceptance.

	Although MVSS has many training capabilities that can improve
	workplace safety, there are significant opportunities to
	improve the system.

	Making the hardware of the simulator more realistic can enhance
	immersion of the trainee into the physical experience of
	operating a truck.  The current MVSS hardware is shown in Figure
	4.  Hardware, in this case, includes output
	devices, such as large-screen monitors and displays; and input
	devices, such as realistic accelerator and brake pedals, gear
	shifters, and steering wheels.  More ambitious implementations
	could be built around an actual truck cab, much as commercial
	jet simulators are based on an exact duplicate of the
	aircraft's cockpit. 

\begin {figure}[h]
   %\centerline{\psfig{figure=production1-new.ps,height=2.5in}}
   \centerline{\psfig{figure=production2.ps,height=2.5in}}
   \caption{MVSS Trainee Interface with steering wheel, gear shift, and gas/brake pedals.}
   \label{fig:sim-interface}
\end{figure}

	MVSS software can also be improved. Simple improvements to MVSS
	could include a broader variety of hazards to challenge the
	trainee. For example, due to the structure of surface mines,
	small rock slides can occur onto the haul road.  Therefore, the
	addition to MVSS of a falling rock in front of a moving truck
	would improve the simulation. The current version of MVSS
	supports just one trainee at a time. A distributed MVSS would
	allow adding additional trainees to the same simulation. It is
	quite 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. Depending on the implementation of
	the distributed MVSS, the trainees might not even need to be
	located in the same physical area.

	The current version of MVSS could be further improved by adding
	sound support. Sound has a large effect on the realism of
	any virtual reality system. For example, the engine sound of a
	Caterpillar hauling truck can be loud and fatiguing. In a
	real truck, this engine sound could effect the ability of the
	trainee to concentrate and respond to a given situation. A MVSS
	with sound support would add this realism, better preparing the
	trainee for actual mine operations. Sound support would also
	increase the number of simulation scenarios possible. As an
	example of a scenario not possible without sound, consider one
	that included the production of engine noise that
	simulated a specific engine problem, with the trainee's
	recognition of the sound and response scored.


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