Last July, Australian airline Qantas launched one of the world's most advanced passenger check-in systems, promising an improved passenger experience - although it seems that not all of the airline's customers are impressed.

The technology, dubbed the 'Next-Generation Check-in' system has caused a spike in passenger-staff confrontations at Perth Airport, where the technology was first introduced, according to reports from the country.

The Australian Services Union (ASU), which represents staff, says that passengers have been left frustrated by the technology, leading to a rise in attacks on staff which has prompted Perth airport to issue panic alarms to some workers.

The new system was made available to approximately 100,000 Qantas frequent flyers last year, all of whom were issued with a special card which acts as a permanent boarding pass and allows them to check in with a single swipe.

Instead of handing their bags to a staff member, pre-registered users weigh and hand over their bags themselves, paying any excess fees through the machines, something which the ASU says passengers simply don't understand.

For its part, Qantas reportedly says that the feedback has been overwhelmingly positive and says that it plans to expand the system, now live in Perth, Melbourne and Sydney, to terminals in Brisbane, Adelaide and Canberra this year.

The Next-Generation Check-in is currently restricted to domestic Qantas passengers, although with the rapid growth in automated travel services it may not be long before other airlines launch similar systems, making Qantas's experience an important test.

Last year, airport technology firm SITA said that it believed 70 percent of air passengers wanted more self-service along their journey, based on the results of interviews with 2,490 passengers travelling through airports around the world.

Almost half of the passengers surveyed said that the only reason they checked in using a traditional desk was because they needed to drop a bag, and 70 percent said that they would tag their own bag (as per Qantas's system) if they could.

Find out more about Qantas' system:

See it in action: