In a recent white paper, Wenco Mining Systems looks at the next steps to make sure V2X technology reaches its full safety potential on today’s minesites. V2X has dominated conversations around mine vehicular safety for years. “This vehicle-to-everything communication system currently stands as the most promising solution for reducing the thousands of injuries or fatalities that occur on mine sites each year. Yet, today’s most common V2X systems rely on a technology that actually hinders their full potential for safety in a live mining environment: low-fidelity positioning.”
“Low-precision GNSS provides V2X systems with positional accuracy within 5 m of their actual geolocation — relatively close, but not nearly accurate enough to evade the nuisance alarms that bother operators working in normal and safe proximities. Users of low-precision V2X systems routinely complain of these nuisance alarms, eventually learning to distrust the alerts, become complacent, or turn the system off completely. Options are available to resolve this problem, though. Cameras and LiDAR are two technologies used in mining V2X that reliably improve safety outcomes, albeit with drawbacks. Now, a third solution is making inroads as an effective means of improving proximity detection without the complications of either camera or LiDAR systems: high-precision GNSS.”
High-precision GNSS systems take a different approach to mining hazard detection from environmental sensing systems like cameras or LiDAR. These systems equip vehicles with a high-precision GNSS receiver that can detect its geolocation within 50 cm of accuracy. By adding these receivers to all vehicles on site and updating their positions at a specific frequency, system logic can rapidly determine the likelihood of vehicles colliding with any instrumented asset. “Although popular for commercial vehicles and hotly discussed for mining, camera- and LiDAR-based systems both require an unobstructed line of sight between the system and any hazards in order to function properly. They cannot detect nearby hazards hidden behind a visual blockage, such as a berm or pitwall – regular occurrences on mine sites. Vehicles on a collision course around blind curves or intersections remain vulnerable, unable to receive protection from these systems.”
Conversely, high-precision GNSS-based systems do not require line of sight; they use peer-to-peer radio communication in conjunction with highly accurate geolocations and onboard system logic to calculate potential collisions. Operators remain consistently aware of other vehicles travelling nearby, regardless of visibility. Furthermore, instrumenting vehicles and other infrastructure with high-precision GNSS is also significantly less costly than outfitting them with elaborate technology like LiDAR. The biggest issue with GNSS-based systems is their inability to actively sense their environment. Unless a vehicle or fixed asset maintains a GNSS receiver, it remains undetectable by the system. “Obviously, this technological hurdle reduces the overall level of safety possible in relation to a LiDAR or camera system working in ideal operating conditions. Yet, the advantages of high-precision GNSS still make it a much more viable option for advancing the quality of V2X systems along the complexity-safety curve — and for mitigating vehicular hazards throughout this generation of technology.”
“Along with GNSS, camera- and LiDAR-based options form a curve of adoptable safety technologies for use in mining V2X systems. Each one builds on previous technologies to add supplementary layers of safety, culminating in an ultimate solution that uses high-precision GNSS for essential proximity awareness and sensing technologies to detect nearby uninstrumented objects.”
For most mining operations, Wenco believes that high-precision GNSS represents the sweet spot in this curve — the point of greatest return on investment. It allows hazard detection around visual obstructions, an essential requirement for industrial vehicular safety, and its comparatively low cost and flexibility enable widespread use across site. “True, these systems do not actively sense their environment, but instead function at a deeper level — preventing equipment operators from placing themselves in situations that would necessitate environmental sensing in the first place. When joined with an open communications protocol like 802.11p, a high-precision GNSS-based V2X system allows vehicles to communicate their highly accurate geolocations rapidly, maintaining constant peer-to-peer proximity awareness without constant Wi-Fi network coverage.”
The modest cost of GNSS technology also allows mining operations to instrument more units than practical with other approaches, enabling contractor equipment and other non-standard units to easily receive protection from the system. Hence, a preferred approach for enhancing mine safety in 2019 involves a combination of high-precision GNSS and 802.11p technologies.
A typical V2X system that uses high-precision GNSS outfits both heavy and light vehicles at the mine site with an integrated set of computers and radios. Light vehicles receive a single high-precision GNSS receiver mounted on their roofs. Heavy vehicles use two similar receivers, the additional one mounted at the opposite end of the vehicle. This secondary receiver allows the V2X system to calculate accurate heading in addition to its geolocation and speed. Unlike light vehicles, the direction of travel for heavy vehicles is a chief concern while spotting and loading at shovels, so they require this secondary receiver. These receivers send their data via Ethernet to an onboard router, which connects them to a ruggedised onboard computer and its monitor. Beyond standard processing, storage, and networking capabilities, these computers also include an 802.11p communications device that allows them to transmit and receive data directly without passing it through a site-wide network.
Users travel throughout the mine site on either a heavy or light vehicle, observing the position of instrumented vehicles as necessary on the V2X system display. Every second, the high-precision GNSS updates the vehicle’s geolocation and receives a correction from the site-wide network. Using 802.11p, the vehicle communicates its position directly to other instrumented vehicles up to a kilometre away every 100 milliseconds. Receiving this data, onboard displays update with a visual indicator and provide an audio alert to make operators aware of any vehicles working at a safe distance nearby. If the system determines that two or more vehicles may collide, it sends a more severe audiovisual alert to the respective operators — in effect, prompting them to focus on their surroundings and cease accel-eration. A third level of audiovisual alert serves as an emergency alarm, demanding operators brake immediately to avoid a highly probable collision.
“Of course, these options are merely stop-gap measures along the path to mining autonomy. A fully autonomous mine results in the pinnacle of industrial safety, keeping equipment and operational personnel segregated. Before the mining industry can achieve it, though, several essential capabilities must emerge. V2X with high-precision GNSS moves mining further along this capability adoption track. LiDAR- or camera-based technologies that supplement high-precision GNSS take proximity awareness further, but they still remain firmly within the boundaries of proximity awareness — not true collision avoidance. To advance to this next tier of safety, systems would need to interrupt operator control over their equipment and activate their braking systems. Although such technologies are gaining ground in recent models of commercial vehicles, they have yet to see widespread adoption. Industrial vehicles involve parameters, such as stopping time, that are significantly different from commercial vehicles. Likewise, they operate in less predictable environments. While these systems are eagerly anticipated for mining, they are still in early stages of development.”
However, autonomous braking systems also serve as a prerequisite for autonomous haulage as a whole — a topic of major interest to the mining industry. Autonomous vehicles raise the level of safety in mining environments even higher, further separating heavy equipment from site personnel. Much discussion and anticipation circles through mining communities about the advent of autonomous vehicles, but mining companies continue to struggle with a core problem of the technology: interoperability.While all major mining OEMs are rapidly developing autonomous haul trucks, most of them function through siloed, proprietary protocols. “With virtually all mining operations running mixed fleets from multiple OEMs, the industry must solve this interoperability issue prior to adopting autonomous equipment and witnessing their safety advantages. Industry advocates for open technologies are currently working with the International Organisation for Standardisation (ISO) to develop standards for autonomous control system interfaces, which ought to ease the adoption of autonomous technologies. The establishment of these open standards is fundamental to advancing mining vehicular safety beyond collision avoidance, which itself does not preclude the possibility of injury or fatality.”
“All of these higher order systems and integrations that improve mine safety rely on those systems and integrations that come before them. At the root of these improvements lies V2X — the vehicle-to-everything communication system already used in many industrial applications. Yet, the step beyond the bare basics is high-precision GNSS — a technology that simply integrates into current V2X structures, but one that fundamentally transforms the experience of using it. Even with the most advanced com-munications protocols like 802.11p, V2X proximity awareness depends on locating potential hazards with high degrees of specificity.”
“Low-precision GNSS receivers can only ascertain their global position within 5 m — resulting in probable false alarms when two equipped vehicles pass each other less than 10 metres apart. Users of these systems recognise the poor accuracy of their alerts and quickly learn to ignore them or, worse, turn off their machines. Without acceptance from users, a V2X system is as good as no system at all. High-precision GNSS turns that problem on its head. High-precision V2X places its receivers’ geoposition within 50 cm, so operators only receive meaningful alarms when collisions appear highly probable.”
Other technologies such as LiDAR and camera banks can actively sense hazards in the proximity, but concerns around line-of-sight requirements and faulty readings in poor visibility — not to mention cost — make them work best as secondary, supplementary technologies at a point later in the mining vehicular complexity-safety curve. “They serve as a step beyond high-precision GNSS, moving equipment further and further along the safety spectrum toward proactive, machine learning-based collision avoidance, autonomous haulage, and full mining autonomy. Each of these forthcoming safety solutions can further increase safety throughout mine operations, but they require several precursor technologies and systems to prove themselves before seeing widespread adoption. In the meantime, high-precision GNSS offers a cost-effective, easily deployable means of moving mining safety along this curve, reducing false positives, raising operator trust, and — most importantly — improving the safety of mining for all the industry’s personnel.”