\subsection{Wall Following Tasks}\label{wfTasks}


The wheelchair was driven in the Empty Hall VE which consists of a large empty room bounded by four walls (\hyperref[fig:wfmap]{Figure 5.3}). The volunteers were asked to select a side for wall following and then instructed to move the wheelchair close to the wall appropriately. In manual mode, they were asked to follow the wall using minimal keypad inputs to maintain the wheelchair within an arm's distance from the wall (i.e., keeping the wheelchair within a zone of about 6 tiles from the wall as shown in \hyperref[fig:wfmap]{Figure 5.3}. The first three tiles from the wall span a distance of approximately 65cm and the width of the wheelchair is roughly 65cm. Hence the wheelchair was required to be maintained within 6 tiles to be at arm's distance from the wall. The task involved negotiating three walls and two corners. A similar route was taken in the shared control mode. They were asked to bring the wheelchair back within the prescribed zone if it exited it and also provide corrections to the corner navigation if required.
