A simulator for both manual and powered wheelchairs in immersive virtual reality CAVE

C Genova,A Prini,G Reni,E Biffi,M Sacco,C Corbetta,D F Redaelli,A Davalli,S Arlati,M Malosio

doi:10.1007/s10055-021-00547-w

Abstract

A large number of people in the world need to use a wheelchair because of different disabilities. Driving a wheelchair requires complex physical and cognitive abilities which need to be trained. Virtual training helps users acquire driving skills in a safe environment. The aim of this paper is to describe and technically validate simulation models for both manual (MW) and powered wheelchairs (PW) based on immersive virtual reality CAVE (VR). As VR system, the Gait Real-time Analysis Interactive Lab (GRAIL) was used, a CAVE equipped with a motion platform with two degrees of freedom and an optoelectronic motion capture system. A real wheelchair was positioned onto the motion platform with rear wheels free to turn in MW modality, and a commercial joystick was installed on an armrest to simulate the PW modality. Passive markers were used to track the wheel rotation, the joystick and the user hand motion. Custom D-flow applications were developed to manage virtual scene response to user actions. Overground tests, based on single wheel rotation, were performed to verify the simulation model reliability. Quantitative results demonstrated that the MW simulator kinematics was consistent with a real wheelchair overground in the absence of wheel slip and inertia (median error for MW 0.40 °, no systematic bias p = 0.943, high correlation rho > 0.999, p < 0.01). The proposed solution is flexible and adaptable to different wheelchairs, joysticks and optoelectronic systems. The main limitation is the absence of force feedback. Nevertheless, it is a reliable prototype that can be used to validate new virtual scenarios as well as for wheelchair training. The next steps include the system validation with real end users and assessment of the simulator effectiveness as a training tool.

Highlights

According to estimates of the World Health Organization, 75 million people in the world were using a wheelchair in 2018 (WHO 2018)
The quantitative test of the MW simulator assessed that the developed model, based on the hypothesis of absence of wheel slipping phenomenon and inertia, was consistent with overground movements of a real wheelchair
This work aimed at describing a new simulation system, based on an immersive virtual reality CAVE (VR) CAVE that integrates both manual and powered wheelchairs

Summary

Introduction

According to estimates of the World Health Organization, 75 million people in the world were using a wheelchair in 2018 (WHO 2018). Wheelchair driving requires complex physical and cognitive abilities, such as vision, balance, spatial awareness and a general knowledge of the wheelchair characteristics and reaction times (Bigras et al 2020; Morgan et al 2017; Pithon et al 2009). It is important for people with physical disabilities to manage all these skills. Some studies have highlighted that the risk of tipping over, falling and colliding with static or moving objects in the environment is not negligible (Corfman et al 2003; Kirby et al 1994; Rice et al 2019; Xiang et al 2006)

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