Dual-IMU-WIP: An easy-to-build Walk-in-Place System based on Inertial Measurement Units

Locomotion interfaces for virtual environments remain an active field of research. Walk-in-place (WIP), where the intent to move is communicated to the system by taking steps on the spot, provides a realistic experience to the user without being confined to a limited tracking area. The proposed systems found in the literature have complex setups, require bulky hardware, and use closed source software, which makes reproduction of the results as well as follow-up research difficult or impossible. We propose an easy-to-build wireless WIP system based on consumer grade electronic components which is versatile, affordable, and extensible. We use the rotation and position data of inertial measurement units attached to the user’s left and right shin, perform signal processing directly on the device, and show how to use this data for continuous movement in a virtual environment. Our locomotion interface uses a state machine and features low start and stop latencies as well as the detection of foot gestures for rotation and sideward movements. The proposed device is small enough to be mounted on a pair of shin guards. We developed an exercise application to proof that our system works in a practical scenario, where the user moves through a virtual environment by using her/his legs only. We publish building plans of the device and make our software open source in order to make our results replicable and allow for follow-up research.