IM 2020 July/August 20 | Page 28

HIGH PROFILE Optimising fleets with uninterrupted connectivity By Chris Mason, VP of Sales for EMEA at Rajant Corporation Underground mines are some of the most challenging places to deploy technology in the world. Despite significant technological breakthroughs over the years, laying the foundations required for fibre networks still requires a great deal of care and management. Traditional wireless networks must still be connected at various points to the same fixed fibre infrastructure that can easily be damaged but not easily relocated. This creates a problem in the ever-changing layout of an underground mine. In such environments, it is vital the network is able to reach every corner of the mine and adapt with miners’ movements to provide constant, uninterrupted communications. Enhanced connectivity on the surface On the surface, equipment and infrastructure must be moved almost daily away from new blast zones, which means the network that provides vital connectivity must frequently shift as well. This creates a problem for traditional wireless networks that operate from fixed infrastructure. One innovative solution has seen equipment, people and vehicle fleets equipped with wireless technology and sensors to stream real-time data back to a command centre. This includes everything from a machine’s current location to its tyre pressure, enabling operators to gain full visibility into the health status and performance of every asset. Rajant’s Kinetic Mesh ® network architecture allows open-pit operations to easily introduce, relocate, or remove network infrastructure. It does this by placing lightweight BreadCrumb ® nodes on fixed or moving assets, such as trucks and shovels, uniquely enabling vehicle-to- vehicle (V2V) communications between mobile equipment. That means nodes can be relocated without causing any downtime, and interference or signal blockage caused by the changing openpit environment will not compromise network performance. Flexible underground networks In the most challenging underground environments, open-pit know-how is leveraged to solve networking shortfalls where connectivity and throughput demands are high, but infrastructure places limitations on how far wireless signals can travel. Typically, an underground mining network requires fibre to every device. But installing fibre in active drives, panels and declines is challenging to schedule and can create operational and maintenance nightmares. Also, development, drill and blast areas can rarely support any fibre infrastructure, while trucks have been known to accidentally catch and rip down sections of fibre, dramatically affecting coverage. As on the surface, it is possible to create a complete underground wireless network for mission-critical data, video, and voice communications. By using communication nodes attached to fixed and moving objects within the mine, a flexible network is created that can go wherever needed without requiring the installation of cumbersome equipment and infrastructure. Predominantly used in hard-rock or metalliferous mines, but just as easily installed in soft-rock mines, a combination of Rajant BreadCrumbs and Poynting wide-band, bi-directional, circular polarised antennas are being used on more than 200 underground sites around the world. BreadCrumbs maintain multiple simultaneous connections between peers and can send and receive information on different frequencies, mitigating issues due to interference, congestion, and equipment outages. Poynting antennas provide bi-directional coverage with dualfrequency Wi-Fi connections to assist in propagating signals around tunnel bends and to and from moving machinery. The system is especially useful in providing expanded coverage in mining production and new development areas where there might be daily blasting operations or where existing infrastructure is minimal. Network coverage can be easily extended or changed as the mine develops too. With nodes on all production vehicles, the network travels with the equipment into areas where existing networks find limitations or no coverage at all. Each node can be a mesh node, an access point, a bridge or a switch depending on the role an operator wants it to play. Because each node operates on two frequencies simultaneously, they can be connected to the rest of the mesh and act as a standalone Wi-Fi access point at the same time. This has proven to be particularly useful for mine surveyors and geologists who do not have to wait to get back to the surface to get connectivity for their phone or tablet. Networks and automation By deploying autonomous equipment for drilling and haulage, mines can achieve production and safety gains without the presence of an operator. The challenge is that autonomous applications are not only bandwidth-intensive, but most require continuous, uninterrupted communication otherwise the autonomous vehicle has to stop due to safety reasons until communications are re-established. With network nodes attached to vehicles that can connect wirelessly, via multiple hops, back to a primary fixed network, a mesh network is the perfect solution for sending vehicles to places people cannot access. An example is Australian Droid + Robot (ADR). This Brisbane-based underground robot and drone survey specialist was selected to inspect an abandoned mine in Queensland by the Department of Natural Resources, Mines and Energy (DNRME). ADR chose Rajant Kinetic Mesh to enable it to remain in constant communication with each robot while underground. The Collingwood tin mine site, located 30 km south of Cooktown, had inadequate ventilation and ground support. There was also visible water making it a difficult terrain to traverse, yet the inspection needed to determine the condition of the bulkhead, which would be out of range of ADR’s line-of-sight remote control. The mine had, therefore, been deemed by DNRME to be too hazardous for human inspection, so it looked to trial the safe alternative ADR had to offer. Every ADR robot had a BreadCrumb node onboard enabling it to independently perform visual inspections, thermal imaging, laser survey scanning, gas sensing, and other tasks to identify and/or operate in the hazardous mine conditions. The network also uniquely enables these autonomous systems to communicate V2V and create an autonomous mesh network to manage their movements throughout the mine. Regardless of the issues, Rajant’s Kinetic Mesh maintained uninterrupted high throughput and low latency to overcome any obstacles. ADR’s robotic ‘inspectors’ were enabled to independently scan, sense, and explore on behalf of DNRME personnel. It’s not just equipment that can be connected. Wi-Fi tags for personnel are emerging as a solution designed to be used in hazardous work areas. Underground, like in other industrial settings, personnel tracking is an essential requirement to improve situational awareness and communication – delivering real-time visibility, which is needed to maximise the safety, security and productivity of personnel. With the Rajant-Poynting solution, underground mines can enhance network capacity and mobility to run advanced applications that power greater safety, efficiency, and autonomy – all without the use of expensive fibre. IM 26 International Mining | JULY/AUGUST 2020