Technologies that drive proximity detection

Image: Strata Worldwide

No matter how advanced mining becomes, reducing the risk of unintentional interaction between miner and machine continues to be a vital component of safety.

The industry reports injuries and even deaths each year, due to unsafe contact with mobile equipment.

In response, a range of proximity detection technologies and collision avoidance solutions have emerged on the market over the years, all in an effort to reduce – and hopefully eliminate – these hazards.

But how does a mine decide which one will be most suitable for its needs? Some questions to ask include:

  • Do you want a system to simply assist machine operators to see their surroundings before and during operation?
  • Do you want a system that warns operators with alarms to alert them of hidden obstacles and potential dangers?
  • Or do you want a fully interactive system that detects possible dangers, sends warnings to personnel involved and can take action to prevent a collision?

Cameras

Camera systems with display screen provide a view of the surrounding areas and the ability to monitor when personnel and other vehicles are approaching or in a precarious location.

Radar

Radar systems work by installing a sensor at the front and rear (and sides as applicable) of machinery to send out pulse waves and detect reflections or shifts in frequency.

Such an indicator represents the presence of an object or pedestrian, and an alarm is triggered for the machine’s operator. Any object will be detected, and no receiver/tag is required.

RFID

Radio Frequency Identification (RFID) systems for proximity detection in mining and construction work by using an “activator” installed on machinery and small battery-powered “tags” worn on a miner’s person.

The activator sends out RF pulses to create a “read field” around the machine and any tag within range is, per the name, activated. When this happens, the tag sends out a location signal to alert of its presence and trigger a warning alarm to the machine operator.

Global Positioning Systems (GPS)

Similar to consumer products, GPS uses satellite signals to triangulate a position based on latitude and longitude.

For collision avoidance, the system then shares location data with other vehicles by using radio frequencies.

Two-way communication between vehicles allows operators to monitor the locations and movements of others so collisions can be avoided.

Ultra-Wide Band (UWB)

Ultra-Wide Band is a newer technology that uses a wide spectrum of radio frequencies to create two-way communication between system transceivers.

Transceivers are installed on machinery and vehicles and are carried by personnel. The time-of-flight (ToF) of the RF signals is used to obtain the distance between and the position of the objects.

Electromagnetic (EM)

Electromagnetic systems work with field generators and personnel-worn receivers. The generators are installed onto equipment and create electromagnetic zones that surround the unit.

Personnel wear Personal Alarm Devices (PADs), which detect these zones and trigger alarms of warning to all parties when the zones are breached.

If elected by the mine, the machine will automatically slow its speed or stop completely when the warning and hazard zones are breached.

This interlocking capability ensures the highest level of personnel safety while working around operating machinery.

No two are the same

All technologies discussed here have been used in active working environments. Radar and GPS have been strongly adopted into surface applications, as well as the use of cameras.

Electromagnetic systems, while newer to the surface mining industry, can be used in conjunction with far-field technologies. It is ideal for close-range blind spot coverage for vehicles starting up, reversing and traveling at slow speeds.

Given the nature of the underground working environment, with factors such as low visibility, confined work areas, physical barriers and the heavy presence of mobile machinery, electromagnetic proximity detection has over the years been proven to be the most effective technology for these environments.

The core technology of Strata’s HazardAvert system is refined for these applications and has demonstrated high accuracy in close quarters. It has the capacity to function with hundreds of vehicles and pedestrians in close proximity without latency or delay.

For more detailed information on these technologies, please read Strata Worldwide’s blog here.

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