Collision Avoidance Systems (CAS) play a critical role in mining operations by significantly reducing the risk of accidents involving workers, vehicles, and machinery. These systems are designed to prevent collisions that can lead to injuries, equipment downtime, and decreased productivity, ultimately impacting the bottom line of a mining operation.
Key functions of CAS include monitoring the positions of workers and equipment, providing alerts to operators and pedestrians when they are in close proximity, and automatically limiting machine motion in severe cases.
However, these systems can be prone to producing false alarms, technically referred to as false positives.
Several factors contribute to the occurrence of false positives in CAS:
Understanding the technological underpinnings of CAS helps clarify why false positives occur and what can be done to mitigate them.
CAS typically integrates various technologies such as Time-of-Flight, radar, LiDAR, Low-Frequency sensors, GPS, and computer vision. Each of these technologies has its strengths and weaknesses, and their combined use is intended to provide a robust detection system.
However, the complexity of integrating the correct combination of sensing technologies introduces potential points of failure, particularly if the incorrect technology selections are made for the specific operational environment.
For instance, comparing Time-of-Flight with Low-Frequency (LF) sensors highlights the trade-offs between repeatability and detection range. LF field generation offers strong repeatability and can penetrate obstacles, but it is limited by its detection range.
On the other hand, Time-of-Flight technology excels in range and accuracy but lacks the ability to penetrate objects, making it less effective in environments where obstructions are common.
If only Time-of-Flight (ToF) technology is used in a CAS, the system often compensates for ToF's inability to penetrate obstacles by enlarging the detection zones. This broadening of zones increases the likelihood of false positives, as the system may trigger alerts for objects or scenarios that do not pose a real threat.
However, by combining ToF with Low-Frequency (LF) field generation technology, the detection zones can be made smaller and more precise. LF’s ability to penetrate obstacles complements ToF’s range and accuracy, allowing the CAS to accurately detect objects behind barriers while reducing unnecessary alarms.
This overlap between the two technologies not only mitigates the risk of false positives but also enhances the system’s overall reliability, providing a more effective safety solution in complex mining environments.
False positives in CAS can have significant adverse effects on safety, production, and costs as per the examples below:
Safety:
Production:
Costs:
The human element in operating CAS-equipped machinery cannot be underestimated. Operators are the first line of interaction with these systems, and their response to false positives can make or break the effectiveness of CAS.
Training is critical to ensure that operators understand the importance of the alerts and how to appropriately respond to it. However, excessive false positives can erode operators’ trust in the system, leading to a dangerous cycle of ignoring alerts and increasing the risk of genuine collisions.
Operators who lose faith in CAS due to false positives may develop habits of disabling the system, either partially or entirely. This practice, while addressing the annoyance of false alarms, reintroduces the original risk of collisions that CAS is meant to prevent. It is essential to strike a balance where the system is trusted and relied upon without causing undue frustration.
To mitigate the impact of false positives, it is crucial to select the right CAS technology and vendor. Here are some guidelines:
Collision Avoidance Systems are vital for enhancing safety and productivity in mining operations. However, the occurrence of false positives can undermine its effectiveness, leading to operator frustration, reduced efficiency, and increased costs.
By understanding the causes of false positives and selecting advanced, reliable CAS technologies, mining companies can mitigate these issues. Investing in premium CAS solutions not only enhances safety but also protects the bottom line, making it a sound investment for any forward-thinking mining company.
Article written by: Eric Baker, Global Product Manager, Epiroc.
