A New Approach to Walking in Place

Abstract

Abstract. Walking in Place (WIP) is an important locomotion technique used in virtual environments. This paper proposes a new approach to WIP, called Speed-Amplitude-Supported Walking-in-Place (SAS-WIP), which allows people, when walking along linear paths, to control their virtual speed based on footstep amplitude and speed metrics. We argue that our approach allows users to better control the virtual distance covered by the footsteps, achieve higher average speeds and experience less fatigue than when using state-of-the-art methods based on footstep frequency, called GUD-WIP. An in-depth user evaluation with twenty participants compared our approach to GUD-WIP on common travel tasks over a range of short, medium and long distances. We measured task performance using four distinct criteria: effectiveness, precision, efficiency and speed. The results show that SAS-WIP is both more efficient and faster than GUD-WIP when walking long distances while being more effective and precise over short distances. When asked their opinion via a post-test questionnaire, participants preferred SAS-WIP to GUD-WIP and reported experiencing less fatigue, having more fun and having a greater level of control when using our approach.

The Perceived Naturalness of Virtual Locomotion Methods Devoid of Explicit Leg Movements

“…Unlike real walking the feet motion is predominately vertical and the time it takes to perform a step in place may also be lower than taking an actual step. For that reason Bruno et al [2013] suggest that, instead of primarily relying on temporal characteristics of the WIP gait cycle, one might use the footstep amplitude (the step height). Seeing as the gestures used for the current study differed considerably from actual walking the algorithms used to generate the virtual speed relied on estimations of both f and l. Because the virtual velocity was given as the product of the f and l it was ensured that a combination of very short step lengths and unnaturally high step frequencies would not produce exaggerated velocities.…”

“…Indeed, measures of step frequency have previously been used to estimate virtual walking speed in relation to WIP locomotion [Wendt et al 2010]. However, the relationship between real gait parameters and walking speeds might not be ideal for generation of virtual movement in relation to WIP locomotion [Bruno et al 2013]. To be exact, Bruno et al [2013] highlight that the physical movements of stepping in place differ from those of actual walking.…”

“…However, the relationship between real gait parameters and walking speeds might not be ideal for generation of virtual movement in relation to WIP locomotion [Bruno et al 2013]. To be exact, Bruno et al [2013] highlight that the physical movements of stepping in place differ from those of actual walking. Unlike real walking the feet motion is predominately vertical and the time it takes to perform a step in place may also be lower than taking an actual step.…”

Walking in Place Through Virtual Worlds

“…The successor of the LLCM-WIP-called Gait-Understanding-Driven Walking-In-Place (GUD-WIP)-similarly derived walking speeds from the velocity of the user's vertical heel movement, but did so using an optical motion capture system [31]. One of the most recent WIP techniques-Speed-Amplitude-Supported Walking-in-Place (SAS-WIP)-also used optical motion tracking but relied on the footstep amplitude rather than heel-motion velocity [6]. Continuous tracking of the user's movement can also be achieved using commercially available hardware.…”

“…This approach was chosen since steps in place, unlike real walking, predominantly involve vertical motions and each step may also take less time to complete. Specifically, the virtual velocity is calculated through multiplication of the foot speed and a scale factor based on the foot amplitude, and movement is stopped when both feet are grounded for more than an amount of time which is varied based on the foot speed [6]. Finally, Langbehn et al [12] have proposed LeaningAmplified-Speed Walking-in-Place (LAS-WIP).…”