Preventing Stacked Luggage in Airport Baggage Retrieval Systems

Every day, airport baggage claim systems distribute large quantities of luggage items to passenger-facing conveyor carousels, sometimes combining checked bags from multiple arrived flights. As passengers retrieve their belongings, space opens up for additional baggage from the sortation system. If passengers are delayed in getting to the carousel and locating their items, luggage can accumulate and potentially stack on top of each other, making retrieving luggage more difficult. Minneapolis-St. Paul International Airport (MSP) needed a way to prevent luggage congestion on its baggage claim carousels at Terminal 1. Specifically, the airport needed a technology to stop infeed conveyors when carousels fill up and restart them once space is cleared.

The airport chose Banner Q5X background-suppression sensors. These were installed a few feet upstream of the carousel infeed conveyor, with the output programmed for a distance of about three feet to sense when a bag moves passed. When one of these sensors detects a bag, signals are sent to stop the infeed conveyor from sending more bags down until the area is clear again.

There are several reasons why the best-in-class Q5X laser sensor is particularly well suited to this application:

• First, unlike photoelectric sensors that use gap identification (checking for spaces between items on a conveyor, which allow a beam of light to pass through uninterrupted), the Q5X uses laser technology and an algorithm to detect changes in distance, providing a much more accurate identification for the physical position of objects.
  
  
• Second, the Q5X series features extraordinarily high excess gain. This means that the laser emitter has enough power to detect targets of any color, including dark black targets on a black background. This is important, considering that black is the most common color for checked luggage.
  
  
• Third, because the Q5X is a laser measurement sensor, it does not require a separate receiver or reflector on the opposite side of a conveyor belt as a photoelectric sensor would. Rather, it calculates the position of objects by the angle of the laser beam as it bounces back from the target. Because the sensor beam returns directly from targets, airport maintenance teams do not need to add holes to the conveyor side guards for mounting a receiver or reflector, which reduces the chances of straps and tags getting caught and causing jams or damaging the luggage.

The Metropolitan Airports Commission, which owns and operates MSP International Airport comments that “The addition of the sensor and changes to the bag stop have reduced baggage jams at the carousels and have improved guest safety.”