OPERATIONS MANAGEMENT
environment and measure up to ranges of 250-350m.
2D lidars, such as Sick’s LMS1000,
The latest sensor solutions can act as extra pairs of eyes
KEEPING EYES ON Neil Sandhu discusses collision avoidance in the outdoors T
he mining sector faces increasing pressure to structure safe work procedures and processes in outdoor environments, without
compromising on efficiency or productivity. Accident-free navigation of mobile machinery, as well as efficient and safe loading and unloading of materials, are major everyday challenges. Failure to make adequate provision for collision avoidance could lead to unplanned stoppages, expensive delays, reduced throughput or personal injury. But, in surface mines, quarries and
stockyards, static and mobile machinery can be lumbering giants that struggle to see around every corner and obstacle. Large machines frequently work together in confined areas. Driver-operated mobile vehicles such as bucket and shovel excavators, haul trucks and wheel loaders, have considerable blind spots that impair operator visibility. Te harsh environment, weather conditions and difficult terrain all add to the risk of stoppages. Sensing technologies provide the “eyes”
to “see” around the corners and through the dust clouds. Increasingly, with Internet of Tings (IoT) intelligence, they also feed their data back and integrate with automated software and maintenance systems. Technologies such as lidar and radar combine with gateway systems to help mine operators to reduce potential
22
www.engineerlive.com
dangers and increase operational efficiency. But what kinds of “eyes” are best?
LIGHTING THE WAY Laser distance sensors and lidar are common technologies used for collision avoidance in outdoor industrial environments. Tey use optical time of flight (ToF) technologies to send invisible, but safe, infrared light beams to an object and measure the time they take to be reflected back to the sensor. Sick’s laser-based sensors overcome harsh environments using the company’s HDDM+ technology and send out multiple echoes – up to five – to overcome the limitations otherwise caused by bad weather, bright light, dust, smoke or mist. Te sensor automatically filters out irrelevant reflections, such as from water droplets or dust particles, and reliably identifies the actual measurement signals. As a result, the risk of false trips is eliminated.
2D LIDAR SENSORS
2D lidar sensors scan in a fan-shape around the sensor, creating a plane that can be divided into several detection zones. Mounted on machinery or infrastructure, the best-performing can reach a wide angle of view to the side and behind a scanner, typically up to 275°, although some can scan up to a full 360° around their
perform distance sensing and ranging duties to detect moving and stationery objects and output accurate data that can be processed to measure both lengths and widths. Access into zoned areas can be controlled by creating vertical monitoring areas, for example, to control safe access for people or vehicles. Protection against collisions with over height objects, or with stockpiles, can be achieved by establishing horizontal monitoring areas. Systems can be expanded using RFiD tags, GPS or other sensors to identify manned or unmanned mobile vehicles entering a pre-defined area.
3D LIDAR SENSORS 3D lidar sensors go further by scanning in several measurement levels to map a more detailed profile of the environment and its contours, as well as the shape of objects detected. Sick’s AOS lidar solution combines a 2D laser scanner with the firm’s Flexi Soft safety controller to provide a complete system that can help avoid collisions, with sensor self-monitoring to avoid system failures.
RADAR SENSORS Radar sensors work on similar ToF principles to lidar but they emit electromagnetic radio waves instead of infrared light. Radio waves are not affected by environmental conditions in the same way as light-based technologies, so radar sensors can be the ultimate, super- tough choice for harsh environments and operation during the hours of darkness. Sick’s recently launched RMS1000 radar sensor can achieve 24-hour detection performance with long-range resolution and distance accuracy.
Collision avoidance using the Sick MRS1000 3D lidar sensor
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52
