Development and Experimental Validation of a Minimalistic Shape-Changing Haptic Navigation Device

This paper presents a minimalistic handheld haptic interface designed to provide pedestrian navigation assistance via the intuitive and unobtrusive stimulus of shape-changing. The new device, named the Haptic Taco, explores a novel region of robotic interfaces which we believe to have benefits over other communication methods. In previous work, we demonstrated the use of a 2DOF shape changing interface for navigation without the use of sight. In this paper we seek to explore the potential of minimal 1DOF interfaces, whose simplicity may increase intuitiveness and performance despite conveying less information. The Haptic Taco utilizes the same 'variable volume' concept as a previous device, the Haptic Lotus (2010), but with reduced body compliance and higher force exertion capability. Both devices modulate their perceived volume in relation to proximity to a navigational target (a destination or waypoint). As users walk within an environment, they also attempt to minimize the device volume, finding targets via an embodied 'steepest descent' method. Experimental comparison of the Lotus and Taco in a target-finding study revealed that the Taco interface increased motion path efficiency by 24% over the Lotus, to 47% average efficiency. This result is highly comparable to the mean motion efficiency of 43.6-48% observed in prior experiments with the 2DOF shape-changing interface, the Animotus. The findings indicate the potential for minimalistic interfaces in this emerging field.