Published in June 2005 Australian Longwall Magazine

The CSIRO-driven research aims to provide mines with a system capable of providing real-time risk management data so the disasters of the past are not repeated. In almost all the mine accidents of the last 20 years, data predicting an impending incident was found to have existed. But because this data was hard to access, was frequently incomplete and sometimes contradictory, it was often missed during critical decision-making.

Modern mine monitoring systems can pour over 20,000 separate data bits into control rooms every few seconds. Embedded in all this information are the critical pieces of information that can tell a mine manager or a ventilation officer something is not right.

Analysis of those charged with incident management shows people are having to make decisions based on less than ideal, or too much, data. Providing better support for critical decision-making is an important driver behind the real-time data project.

The two outcomes are the delivery of the LAMPS (Location And Monitoring for Personal Safety) project and the first version of the Nexsys Realtime Risk Management System – the critical backbone of a hard/software system to manage real-time risk information.

The LAMPS project received funding from the Australian Coal Association Research Program (ACARP) and CSIRO. The Japan Coal Energy Center (JCOAL), ACARP and CSIRO have funded the development of the Nexsys System, with generous in-kind support from Anglo Coal’s Grasstree mine.

It is envisaged these real-time systems will allow mines to monitor critical data drawn from the huge volume of underground sensors and provide timely warnings that will pre-empt and even prevent disasters.

The LAMPS project was developed to report the real-time location of mine workers underground – a need identified by accident investigators at the Moura No. 2 and other disasters.

LAMPS consists of intrinsically safe tags – attached to workers or equipment - and intrinsically safe stationery readers. Monitoring the safety of workers is the primary application of LAMPS but it can also be used to track the whereabouts of equipment. Trials in an underground metal mine last year showed up to 20 tags could be reliably detected at a vehicle speed of 40kmph.

The system is manufactured and sold by Australian communications company MineCom.

The Nexsys system, now in its third year of development, will be the backbone upon which real-time risk analysis is built.

So far researchers have developed a communication protocol converter – essentially a hardware device that can convert any serial protocol language into internet protocols. This is important because of the many differing and sometimes proprietary “languages” used by the multitude of monitoring devices in mines.

In a typical longwall mine, for instance, equipment monitoring is handled by various SCADA systems; voice communications by a mixture of DAC intercom, analogue telephone and leaky feeder systems; while tube bundle and telemetric sensors are employed for gas monitoring. Ethernet-based internet protocols can not only support this wide range of applications, but opens the door for the introduction of a wide range of other ethernet-enabled devices.

Critically, a high-speed Ethernet switch has been developed – believed to be the world’s first fibre-optic IEC (Exia)-certified intrinsically safe (IS) Ethernet switch. The significance of this is that any serial output sensor can now connect into the high-speed communication highway. Up until now, no IS interface existed to allow serial sensor information to be turned into internet protocols and communicated across an IS communications system.

Unlike current data systems, this highway will not be limited by distance, will work when power is down, will not depend on ventilation and will have multiple redundant pathways.

Another nifty device CSIRO has developed is the e-Reporting system – a stainless steel tablet that captures handwritten reports and transfers them instantaneously across the mine’s local area network (LAN).

Consider the possibilities of the next shift having the most up-to-date information immediately to hand with no delays.

At the moment, all monitoring devices will be connected together by fibre-optic cable but eventually wireless access is envisaged, said CSIRO research leader Greg Rowan. Previously a mine inspector and chairman of the Queensland Emergency Exercise Management Committee, Rowan has been involved with mine safety and risk management processes for several years.

Wireless access will open up further possibilities such as the use of web-cameras, wireless PDA (Personal Digital Assistants) units and real-time video streaming over the LAN.

At the heart of the Nexsys system is a set of rules embedded in software, to be defined by people at any particular mine depending on site-specific conditions.

This system continuously checks whether prevailing mine conditions satisfy the rules – is the gas make within certain parameters? Are the ventilation fans working properly?

Simplistically speaking, if the rules are “broken” or diverge from a defined baseline, Nexsys triggers an alarm and can autonomously initiate a series of actions, such as, raising alerts, sending e-mails, SMS text messages or even voice messages.

In reality, the Nexsys rules inference engine functions at a far more complex level. The software is designed to take into account various interacting factors (gas, temperature and pressure say), effectively emulating human decision-making.

Rowan emphasises the point that Nexsys is not designed to replace human logic but is designed to support human decision-making. To be truly useful Nexsys must be in use as part of normal day-to-day activity, Rowan said.

Nexsys allows events to be viewed historically, which would enable a decision-maker to interrogate the data and find out what path of action was taken in a similar situation previously and what the outcome was.

A fully developed Nexsys system could be expected to be governed by 200-300 rules – one risk to be avoided is not to make the decision-support rules too complex.

CSIRO is currently developing rule input wizards to make it easier for mine personnel to set up the rules.

Further down the track a sub-set of rules could be developed that could track health risks. Rules could be set up to track factors like temperature, humidity and shift length to enable a risk profile to be developed for risks such as fatigue, heat stress or dehydration. The possibilities are endless.

But for now, “the vision...click here to read on.