How safety laser scanners can protect people and machines
structure determine how the scanner gets mounted into the system to monitor the needed area(s). Protection zones. Safety laser scanners have multiple protection zones, including the primary protection zone and one or more warning zones. Some can use scanned data for automatic configuration to ignore stationary objects in the warning zones (Figure 3). In some cases, a safety laser scanner can scan multiple zones sequentially or simultaneously. For example, one scanner can support up to 70 unique safety zone sets. On an AMR, this feature enables the scanner to adjust the scanned areas based on the surroundings and speed of movement. Protective field range. It is the maximum distance that the protected area can extend from the scanner. Typical values range from 3 to 10 m. The required protective field range depends on local regulations and the scanner's response time and resolution. Resolution. It is measured in mm and determines the minimum size object the scanner can accurately detect. Typical values range from 30 mm to 200 mm. Response time. Also called detection time, it measures how quickly a scanner can recognize
the approach of an object. Typical values range from 60 to 500 ms. Sampling. Indicates how many times an object must be scanned in succession to be recognized by the scanner. By default, it usually takes at least two sampling scans. However, for some scanners and under some circumstances it can require ten or more successive sampling scans to recognize an object.
SE2L unit can independently scan two adjacent zones simultaneously, eliminating the need for a second scanner and simplifying system design. Low power for battery- operated safety Extending the run times of AGVs and AMRs can be an important consideration. Those applications can benefit from using Omron's compact (104.5 mm) OS32C- SP1-4M safety laser scanner. It consumes a maximum of 5 W (3.75 W in standby mode) and has 70 sets of safety zone and warning zone combinations available, making it suitable for use in complex environments (Figure 4).
Dual protection zones
Safety laser scanners have various features and functions that suit different application needs. For example, IDEC's SE2L safety laser scanners include master/ slave functionality and dual protection zones. The master/slave function enables one scanner to communicate with up to three other scanners. That can significantly simplify system design and allow the use of a lower-cost controller since the safety controller only needs to communicate with the master, which relays the instructions to the slave scanners. The model SE2L-H05LP can be installed using 2 to 20 m long cables, further enhancing flexibility. These scanners have a scan cycle time of 30 ms and can include 32 patterns in the scan area. Using the dual-zone function, a single
Figure 4: This low-power safety laser scanner supports 70 sets of safety zone and warning zone combinations, making it suitable for AMRs operating in complex or dynamic environments. (Image source: Omron)
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