Engineers from the Hasso Plattner Institute have created a system that offers haptic support to avoid crossing virtual objects with our hands and feeling their weight when manipulating them.
Hasso Plattner Institute has conducted research on how to add haptic support to walls and other heavy objects in virtual reality. The main idea is to prevent the user’s hands from passing through virtual objects by applying muscle electrostimulation. The system is able to make the user feel the weight and resistance of objects. The heavier the element is and the more we press it, the stronger the force generated by the system on the opposite muscles to counteract the action. When holding an object we will feel the tension of its weight on our biceps and pectorals, by stimulating the triceps and shoulder muscles.
The system can stimulate up to 4 different muscle groups and through the combination of these is able to recreate different effects such as, for example, pressing buttons placed on vertical surfaces by stimulating the biceps and wrist. In the document they have published and in the previous video, other interactions are also shown such as noticing projectiles, feeling how an element pushes our arm and the operation of walls, among others. In the case of walls, the solution acts quickly as soon as we touch the wall with our fingers, offering a strong proportional force contrary to that of the user to prevent us from crossing it.
The programming has been carried out with Unity and for its operation we use a backpack, which includes the 8-channel electric muscle stimulator that is controlled via USB and a virtual reality viewer with room scale. In this case they have used a mobile viewer and 8 OptiTrack cameras for a room scale of 4,5×4,5 meters, but according to comment they could have also used HTC Vive.
The system uses two designs with the aim of increasing credibility. The first is based on applying a low electrostimulation that allows the user to cross the object about 10 cm and produces the illusion of soft objects. Giving the feeling of having a constant magnetic field that drives the arm in the opposite direction. The second method is based on reducing the duration of the electrostimulation to 300ms, but applying an impulse of maximum intensity, without harming us, which causes a repulsion effect that makes us move our hand away from the object.
The study offers an alternative to face the interaction with virtual objects and concludes that it is an appropriate solution for this type of experiences. The HPI engineers will continue their research to apply the knowledge learned in augmented reality.
