High Speed Package Profiling with Laser Sensors
Sorting parcels and packages prior to delivery is an essential step in shipping and handling. Order fulfillment applications rely on accurate automated sorting to keep costs down, maximize efficiency, and accommodate large volumes of packages during peak shipping seasons. Furthermore, incorrectly sorted packages can delay delivery and reduce customer satisfaction. Keep reading to learn how laser measurement sensors facilitate reliable package sorting, even at high speeds.
To reduce the risk of error in material handling applications, an automated profiling solution is necessary to scan packages to ensure accurate—and fast—sortation. However, it can be challenging to find a reliable solution due to the high speed of the application and the wide variety in color, size, and sheen of packages—from soft packs to polybags, from corrugated boxes to flat envelopes, and from matte finishes to glossy surfaces or tape. A solution is needed that can reliably scan all packages quickly, regardless of target size, color, or reflectivity.
Learn More About Smart Sensor Solutions for Challenging Applications
In a recent application, an OEM that supplies conveyors to end users was looking for a high-speed profiling solution to reliably sort packages into larges (greater than 18 inches high) and smalls (generally envelopes). In this application, if two or more parcels are stacked on top of one another, their sizes cannot be accurately determined, so these are directed into a bin. A worker periodically removes the contents of the bin and places the packages back on the conveyor to be re-sorted.
A failure occurs when a package is placed on the wrong conveyor (for example, when a small flat envelope is sorted with large boxes). These failures occur most often when packages are stacked on top of one another, making it difficult to accurately determine the size of each individual item. The existing solution, a light grid, yielded a failure rate of 2%. The OEM’s goal was to find a new solution that could reduce the failure rate to less than 1%.
The solution: an array of 4-8 LE Series laser measurement sensors mounted above the conveyor belt, looking down at the packages. The sensors scan the parcels as they pass below in order to:
- Determine the size of the parcel (large or small) and ensure that it is sorted to the correct conveyor, and
- Verify that each package has four sides/corners, confirming that it is a single item. If two or more parcels are stacked, the corners are typically offset, indicating an irregularity. These parcels are diverted to a bin for re-sorting.
LE laser measurement sensors are an ideal solution for this application due to performance and versatility to meet 5 key application criteria: high response speed, excellent reliability, robustness, simple mounting, and low-maintenance operation.
1. Fast Response Speeds
The LE laser measurement sensor features fast response speeds within 5-10 milliseconds. Since each sensor operates independently, the response speed is significantly faster than the typical light grid, for greater accuracy at high speeds.
2. Real World Reliability
Laser measurement sensors from Banner can reliably detect any target, regardless of size, color, or reflectivity.
3. Robustness
Compared to other technologies, such as vision solutions, laser measurement sensors are less affected by environmental conditions like fluctuations in ambient light or temperature. The LE sensor can also withstand vibration from the conveyor for long-term, reliable operation.
4. Flexible and Secure Mounting
The ability to mount the sensors up to 1 meter above the conveyor enables flexible mounting. In addition, laser sensors only require mounting and power to one side of the application, whereas an automation light grid requires mounting and power to both the emitter and receiver units mounted on either side of the conveyor. Mounting above the application also means that the sensors cannot be easily knocked out of alignment.
5. Low Maintenance Operation and Predictive Maintenance
Laser measurement sensors are a low maintenance solution compared to competing technologies. There is no need to continually adjust settings after installation, and the sensors are built to last in the most difficult industrial environments. In addition, sensors with IO-Link communication provide remote health diagnostics and let you know when maintenance is needed (such as cleaning the lens) before a failure occurs. IO-Link sensors are also resistant to tampering, since the settings cannot be changed directly on the device.
Overall, a laser measurement solution is ideal for package sorting in order fulfillment applications and helps drives failure rates down—ultimately saving costs and maximizing profits.