Since the advent of large surface mining equipment, there have been ongoing problems with collisions on mine sites. Poor external vision due to blind spots and limited maneuverability are all major contributing factors in mine site heavy vehicle accidents.
According to Mine safety and Health Administration (MSHA) Institute Proximity Detection alerts or Collision Avoidance is defined to be a technology that can be installed on mining machinery to detect the presence of personnel or machinery within a certain distance of a machine.
This technology is able to interact with the mobile equipment or vehicle’s brakes and bring it rapidly to a complete stop.
These systems can be programmed to send warning signals and stop machine movement when the programmed areas are breached. The term “proximity detection” is used to refer to underground mining applications which often are intended to inhibit machine movement. Whereas we use the term “collision warning” to refer to surface machinery applications that typically provide warning signals only.
For the last couple of years different countries have highlighted the dangers of mining, with most fatal incidents found in Chile and New Zealand whereas Wales remains some of the most high profiled.
These cited examples and many more have brought to the fore the dangers of mines and have shown more than ever before the importance of protecting staff from some of these hazardous incidents with collision avoidance technologies by preventing vehicle to vehicle collisions or persons to vehicle.
According to a paper by Advanced Mining Technologies (AMT), published at MiningCongress.com, vehicle-to-vehicle collisions is one of the biggest causes of accidents in surface mine sites around the world, with 58 people being killed in this way in the US alone since 1987.
The paper said that the main reason for collisions in these locations is because of poor visibility, with large mining machinery not providing operators with the best field of vision.
While everything from flashing beacons, walkie-talkies and horn signals have been used to warn other machinery operators of their vehicle’s presence, none have provided a fool-proof protection for mining employees.
Known as collision avoidance technologies, these systems have numerous features to help ensure safety and provide a less dangerous arena to work in. Video cameras can provide pictures around the vehicle in which they are being used to rule out any blind spots, while proximity detection can set off visual or audible alarms, notifying the driver that they are close to hitting another object.
“By nature, large mining equipment operates in proximity to other equipment. Without the use of technology that provides for positive and configurable alarms there is a real danger that operators will become immune to the alarms and therefore reduce the efficiency of the collision avoidance system,” warned AMT.
There are various technology systems that are currently available on the market to help in developing proximity alerts and collision avoidance systems in surface and underground mining. A technology in surface mining includes RADAR (Radio Detection and Ranging), sonar, Global Positioning System (GPS), radio transceiver tags, Laser, Radio Frequency, (RF) and Cameras while the underground mining utilizes technologies such as VHF, UHF and Electro Magnetic (EM).
However, in reference to a research done on method for testing proximity detection and warning technology for mine construction equipment operation conducted by Mark Teaser a Ph.D. Candidate, School of Civil and Environmental Engineering, Georgia Institute of Technology USA; he says in his paper that Standards and regulations mandated by the Occupational Safety and Health Administration (OSHA) in USA have proven imperative to promote safety in mine construction, but are currently not capable of preventing contact collisions between workers and mine construction equipment.
Current safety regulations require passive safety devices such as hard hats, reflective safety vests and other personal protective equipment (PPE). These passive safety devices are incapable of alerting construction operators and workers in real-time during a hazardous proximity situation.
Other safety regulations such as safety training and education can increase the awareness of close proximity issues for construction operators and workers.
The Global Positioning System (GPS).
The Global Positioning System (GPS) has been available for civilian use for more than 20 years now. It is used to enhance safety Collision Avoidance. If all mobile vehicles are fitted with GPS and telemetry systems, they can continuously report their position to a central control base. Software at the base can then analyze the data and warn when two vehicles are on a collision course, as it is done with civilian air flights in crowded air corridors.
Radar is an acronym for Radio Detection and Ranging system used in mining used to improve proximity alerts for a surface haul truck or a remote-controlled continuous mining machine. The operator of a continuous mining machine spends much time close to the mine walls, large power cables, shuttle cars, and other objects that continuously trigger a radar system that have sensors have some unique installation and placement issues. Radar system is suitable in an underground coal mine, miners and machines that are always close to one another. Many underground mining machines run relatively slowly compared to surface haul trucks.
SAFE mine is one company that uses Radio Detection and Ranging to provide a complete range of advanced traffic safety solutions for surface mining. The SAFE mine Collision Avoidance System (CAS) is the world’s most installed CAS for surface mining. It warns with audio and visual indications of possible collisions and supports the operator by improving traffic awareness, especially in blind spots around the vehicle.
It is real-time fleet monitoring solutions to avoid damaging clean-up equipment around heavy rotating machines, and sophisticated displays that present vital information intuitively in truck cabins.
The SAFE mine CAS is a compact collision avoidance system, which increases situational awareness and reduces incidents by actively alerting the vehicle operator to imminent threats.
RADIO FREQUENCY, (RF)
Radio-frequency identification (RFID) is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purposes of automatically identifying and tracking tags attached to objects. The tags contain electronically stored information though some tags are powered by and read at short ranges (a few meters) via magnetic fields (electromagnetic induction).
One of the companies that use Radio-frequency identification (RFID) enhancing proximity alerts is Essen RFID Company. Essen recommends a UHF RFID-based system that tracks the trucks and iron ore that they carry, updates transactions, and saves this information into the RFID server as well as sends it to SAP v 6.0, the existing ERP used by Sesa Goa.
This system enables automation and data updating in near real-time. Efficient automated tracking of over 10,000 mining trucks has led to substantial operational efficiencies.
The system has centralized web-based reporting features that display details of all registered trucks, truck owners/contractors, drivers, date-wise entry/exit reports and summary reports. These reports can be generated in real-time, enabling up-to-date information to administrators.
In addition Orbit Communications is also such company that uses Radio-frequency identification RFID technology to manufacture collision avoidance system. Bodyguard is a TB-PWAS (Tag Based Proximity Warning Alert) manufactured by Orbit Communications to reduce risk of collision by improving driver awareness in mining sites.
Body Guard helps reduce risk of collision by detecting vehicles entering and exiting high risk areas and activating warning lamps and/or traffic advisory signals to alert pedestrians of vehicles in the area.
CAMERA AND VISIONS SYSTEM.
Large mining trucks have an ongoing problem with collisions resulting from poor vision and limited maneuverability. This has resulted in a very high incidence of accidents where large mining trucks collide with other vehicles and occasionally workers on foot. Proponents of camera-based detection systems believe that, although radar is excellent for accurate range estimates, it is not as reliable as a video camera in determining potential false alarms, such as detected road signs. The most challenging problem for camera-based systems is depth measurement.
This could be handled using a stereo system, but such a system is not yet available for rugged applications. For this reason, a camera-based system could also use radar to provide the distance measurement.
The thermal images produced by the PathFindIR are displayed on a 7″ LCD display inside the trucks cabin. They help the driver to avoid accidents.
A PathFindIR Thermal Imaging Camera is a Vision Enhancement System that uses camera-based detection systems to avoiding accidents with mining vehicles. The FLIR Systems PathFindIR is a compact thermal imaging camera that significantly reduces the hazards of driving at night time and in mining sites. It enables drivers to see much further, with improved clarity, than with standard headlights.
According to Test and Measurement Instruments & Equipment Company who are the manufacturer of the Thermal Imaging Camera; the African continent generally has poor street lighting and pedestrians are often under the influence of alcohol and not street wise. This regularly causes road accidents. As a solution the camera in most cases is used to enable vehicle drivers to detect and monitor pedestrians, animals and objects on or near the road in total darkness allowing more reaction time to any potential danger.
Laddartech Company based in Canada advices any potential user and buyer of a collision avoidance and proximity alerts system that when implementing sensing solutions in any machine one needs to properly identify the minimum required operating conditions for the application. It’s important to specify the objects that will be detected, as well as characteristics such as their dimensions and level of reflectivity (color). It is also essential to indicate at what minimal distance the objects will be detected and specify the required detection zone for the application in particular. For example, in a mining application, one may need several wide detection zones for key areas around the vehicle in order to avoid collisions with objects and people. Other needs in terms of accuracy, repeatability and specific interfaces are also interesting points to consider. Once these parameters have been defined, it can be determined which Leddar sensor which is best suited to the application, as it will include the most appropriate optics and other key features that will be valuable for that purpose.
Further, the company believes tha technology is so versatile, easy to integrate and cost-effective that it will cater to an increasing amount of industries and applications in the coming years. Its affordability, performance and ruggedness will allow the technology to gain ground in key sectors such as mining, automotive, transportation and industrial and even entertainment. Moreover, the company believes that it will play a role in environmental applications as their technology is already being used to save water and energy in smart buildings.