A mechanical backpack can enhance the sensation of jumping or falling in virtual reality by sliding a weight up or down.
Simulating forces on the body while in virtual reality (VR), like those you might feel in a roller coaster or a racing car, often requires bulky and expensive hardware that is unsuitable for home use.
Instead, Pedro Lopes at the University of Chicago and his colleagues have developed a backpack, called JumpMod, that can create the sensation of being pulled up or down by modifying the user’s sense of vertical momentum. “You can play lots of tricks just by playing with perception, rather than physically having these massive infrastructures,” says Lopes.
To trick the brain, JumpMod senses within milliseconds the need to give a sense of jumping or falling and then quickly moves a 2-kilogram weight up or down to achieve this.
Lopes and his colleagues used the device to create a variety of effects in a VR simulation. In one part of the game, players collected a token that enabled them to jump higher, helping them to leap over a cow. By moving the weight up as the player was lifting off the ground, JumpMod made it feel as if they were jumping higher.
In another scenario, players had to smash a pumpkin by jumping on it. By moving the weight down as the player was descending, JumpMod made it feel as if they were landing harder.
At the end of the game, the player is lifted off the ground by a bird. The weight in the backpack moved downwards to give a sense of being lifted upwards.
Lopes presented the work at the Conference on Human Factors in Computing Systems in Hamburg, Germany, on 24 April. He says the system could also be used for training people to jump more effectively through physical feedback.
It is a novel VR accessory, but it would be good to see longer-term data on its use to rule out the effect of novelty in the initial studies, says Brendan Walker at the University of Middlesex in London. It could also be more ergonomically designed to avoid putting all of the force through the rucksack straps, he says.