- April 11, 2017
- IDEC Corporation
By Don Pham, IDEC
New laser scanner technology allows plant personnel to address safety challenges with more comprehensive coverage zones and configurations. This article will explore some of these technology advancements and discuss how they help improve safety and optimize operations.
By Don Pham, Product Manager, IDEC
Manufacturing, transportation and logistics facilities all face the same dilemma when it comes to traditional protection devices: they are difficult to implement, only offer limited protection, and often hinder operations. New laser scanner technology allows plant personnel to address these challenges with more comprehensive coverage zones and configurations. This article will explore some of these technology advancements and discuss how they help improve safety and optimize operations.
Protection and Warning Zones
While safety mats and light curtains provide basic protection, each technology is limited in coverage. The limited functionality of these devices leads to much larger warning zones than necessary to ensure safety and comply with industry regulations. These shortcomings can also hinder operations by creating unnecessary downtime when workers must momentarily pass through an area within an oversized warning zone.
The next generation of laser scanners addresses these limitations. With a much smaller form factor and a host of configurable scanning options, it’s often possible for one laser scanner to take the place of multiple devices. Customizable protective and warning zones also allow users to pinpoint hazardous coverage areas with a variety of programmable scan patterns, each of which can be customized for specific areas and distances.
Traditionally, these types of laser scanners were primarily used on tow motors or automated guide vehicles (AGVs) because of their limited detection capabilities. Newer scanners can provide up to a 5-meter protection zone and a 20-meter warning zone, which significantly increases the number of practical applications.
For instance, a robot may require an 18-inch safety zone spanning 180° around a potentially dangerous moving arm. Instead of installing multiple light curtains that would cease operations within the entire 10-foot area surrounding the robot in case of intrusion, modern laser scanners such as the IDEC SE2L can be deployed to shut down machinery only within the desired 18-inch safety area, and issue warnings within an expanded area. When implemented properly, this type of coverage provides plant personnel with the required levels of safety, while also enhancing their range of movement in designated areas near the robot but out of the danger areas.
Figure 1, Dual zone protection. Configurable zones allow for one laser scanner to monitor multiple areas using a variety of detection patterns.
Since protection zones can be configured in a variety of ways, it is also possible for one laser scanner to provide coverage across several different safety areas at once. Figure 1 shows how the IDEC SE2L laser scanner can replace two light curtains in a robot protection zone application. With a 270° coverage radius, up to 32 different area patterns can be covered by a single SE2L laser scanner (Figure 2). To ensure there are no gaps in coverage, the scanner’s laser beam is deployed every 0.125° on a 30-millisecond rotation, with only a 11mm gap between beams at five meters.
Figure 2, Enhanced Detection Zones. The IDEC SE2L safety laser scanner offers 270° sensing angles up to 20 meters away.
Communication and Control
Other challenges with existing laser scanning technology are difficult setup, configuration and routine maintenance. Some scanners must be aligned by hand and manually adjusted, which leading to lost efficiency. Since each deployed laser is a standalone unit with only basic connectivity, coverage zones are often redundant.
The next generation of laser scanners address these issues by offering simplified configuration modes. Users can map out area configurations by uploading video to a PC, mapping the desired scan area, and transferring the information via USB cable or a Micro SD card.
Alternately, a scanner can be placed in a teaching mode to intelligently identify surrounding objects and map out safety zones. Plant personnel can then fine-tune those learned zones for more precise safety notifications and alerts.
To simplify communication with a safety controller, the IDEC SE2L is the world’s first laser scanner with a master/slave mode, allowing up to three slave units to sync and communicate with a master unit. In this setup, a master unit maps out required safety and warning areas within its maximum 270 ° coverage zone. Up to three additional units can then be configured as slaves to fill in coverage gaps. This functionality allows users to create true 360°coverage areas (Figure 3), or a number of other customized protection areas.
Figure 3, Master/Slave functionality. The IDEC SE2L safety laser scanner can be configured in a master/slave setup reduce the number of required connections to the safety controller.
Laser scanners without this master/slave functionality require communication from each of the four units to the safety controller. For instance, an AGV would traditionally require at least four independent laser scanners to cover all 360° of the vehicle’s operating zone. Since these devices do not communicate with each other, the safety controller must provide communication and coordination to provide the required coverage.
The IDEC SE2L scanner only requires communication from the master, cutting the required communication requirements at the safety controller from four to one. This can often allow a less expensive safety controller to be used, providing significant savings. It also can provide much of the required coordination among the master and slave units, offloading the safety controller from this task, and increasing safety because protection is not dependent on communication with the safety controller.
Built-in Ethernet connectivity also allows next-generation scanners to communicate with other devices and share data logs in real time. This functionality is essential since the Internet of Things (IoT) is allowing animatronics and other equipment to self-detect potential problems in real-time. Collected information can then be shared wirelessly to give technicians sufficient reaction time before a potential problem or shutdown occurs.
Imagine the typical setup of a single light curtain around a stationary device. For it to function properly, technicians need to determine the right-sized through-beam sensors, order the correct parts, hang the necessary mounting brackets, and then calibrate the entire system. Not only is this process extremely time-consuming, it also requires frequent maintenance whenever a sensor is accidentally bumped or touched, as this often requires the entire alignment process to be repeated.
The dimensions of the light curtain are often not ideal since the required safety zone is rarely a perfect square or rectangle. Desired mounting options are often unavailable directly outside the safety zone since it is likely within a high traffic area. This forces technicians to improvise with a less than optimal solution, sacrificing floor space and causing numerous unintentional shutdowns by intrusions into the protection area.
The IDEC SE2L laser scanner measures just 80 by 95 by 80mm in diameter, which means a single unit can be installed in a much more optimal location (Figure 4). The unit’s advanced scan patterns can be configured to reduce the safety zone’s footprint down to exact measurements around the machinery, with the ability to add extended warning zones to signify plant personnel approaching a dangerous area. Since additional zones can be added from a single unit or additional slave devices, the coverage is more comprehensive and less likely to require maintenance.
Figure 4, picture of SE2L. Newer laser scanners, such as this IDEC SE2L unit, can replace multiple safety curtains in certain applications.
Installation and setup effort are also minimized since the unit’s programming can be calibrated and reconfigured from a nearby PC or digital device. Data logs can be imported to measure long-term precision or warn of potential problems, giving operators quick access to metrics that matter. Modern laser scanners therefore simplify deployment, while enhancing production and improving safety.
As robotics and machinery grow more complex, safety challenges will increase. While there’s no way to fully determine those upcoming issues, modern laser scanners create a unique opportunity to build smarter, more efficient and future-proof safety systems. This will also become a major factor as the IoT reinvents productivity within the workplace, and as machinery requires additional intelligence to operate at optimal capacity.
Light curtains and other safety devices serve their purpose in many basic and simple applications, but the next generation of safety laser technology offers far more benefits, while reducing configuration and other deployment costs. These advancements will ultimately keep plants and facilities safer and more efficient.
Photos and figures all courtesy of IDECLearn More
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