A shared control solution for safe assisted power wheelchair navigation in an environment consisting of negative obstacles: a proof of concept

Abstract

Power wheelchairs allow people with motor disabilities to have more mobility and independence. However, driving safely such a vehicle is a daily challenge particularly in urban environments while navigating on sidewalks, negotiating curbs or dealing with uneven grounds. Indeed, differences of elevation have been reported to be one of the most challenging environmental barrier to negotiate, with tipping and falling being the most common accidents power wheelchair users encounter. It is thus our challenge to design assistive solutions for power wheelchair navigation in order to improve safety while navigating in such environments. To this aim, we propose a shared-control algorithm which provides assistance while navigating with a wheelchair in an environment consisting of negative obstacles. We designed a dedicated sensor-based control law allowing trajectory correction while approaching negative obstacles e.g. steps, curbs, descending slopes. This shared control proposed method takes into account the humanin-the loop factor. In this study, our solution the ability of our system to ensure a safe trajectory while navigating on a sidewalk is demonstrated through simulation, thus providing a proof-of-concept of our method.

Limited Information Shared Control: A Potential Game Approach

“…Lemma 2 (Boundedness of NPDGs). Given an LQ differential game Γ d and an LQ PDG Γ (p) d defined by ( 3) and ( 11), respectively, where the underlying dynamics system is given in (5). It is assumed that the initial values are identical:…”

“…For the sake of readability, the index (p) symbolizing the NPDG and the time dependencies are omitted in the following. Let the Hamiltonian function of the NPDG be given as in (12) with linear system dynamics (5). To find the NE, an optimal control problem for the potential function (11) with the underlying linear system dynamics (5) has to be solved, which is more simple then solving the coupled Ricatti Equation (6).…”

“…The design of adequate automatic controllers for human-machine shared-control systems requires the consideration and understanding of the control action of the human, which increases the acceptance and the performance of the control system [2]. In literature, there are several problemspecific shared-control concepts for applications like working machines [3], sea excavator [4], in the development of cooperative assistive wheelchair [5] or automated and autonomous vehicles [6], [7], [8], [9]. However, because these concepts are problem-specific, they are not easily generalizable.…”

Vestibular Feedback on a Virtual Reality Wheelchair Driving Simulator

“…Moreover semi-autonomous systems that have currently been developed within research laboratories do not manage all types of complex situations. Indeed, current solutions mainly focus on avoiding obstacles within indoor environments [6,42] and do not yet show sufficiently good performances in more complex situations such as navigation within complex urban environments [34], social interactions with pedestrians [11,18], and negotiation of ramps or curbs [8]. Furthermore, these systems still require good driving skills by the user [20] and thus require training before they can be used in daily life.…”

Power Wheelchair Virtual Reality Simulator with Vestibular Feedback

“…Moreover semi-autonomous systems that have currently been developed within research laboratories do not manage all types of complex situations. Indeed, current solutions mainly focus on avoiding obstacles within indoor environments [6,42] and do not yet show sufficiently good performances in more complex situations such as navigation within complex urban environments [34], social interactions with pedestrians [11,18], and negotiation of ramps or curbs [8]. Furthermore, these systems still require good driving skills by the user [20] and thus require training before they can be used in daily life.…”