Human-Inspired Control of a Whip: Preparatory Movements Improve Hitting a Target

Manipulating flexible and underactuated objects, such as a whip, remains a significant challenge in robotics. Remarkably, humans can skillfully manipulate such objects to achieve tasks, ranging from hitting distant targets to snapping a stick in someone's hand with the tip of a whip. This study explored this problem by constructing and modeling a 25-degree-of-freedom whip. Our goal was to investigate the strategies employed by humans when using a whip to strike a target. To that end, a human-inspired controller was devised that emulated two observed movement strategies: “striking only” and “preparing and striking”. While the latter strategy involved a more intricate and parameter-intensive trajectory definition, our findings revealed that the more complex “preparing and striking” approach enabled the whip to reach targets at greater distances. The outcomes of this study provided first insights into preparatory movements that humans employ when manipulating objects. By directly bridging between human and robot studies, we show how insights into human movements may inform effective robot control strategies for the manipulation of underactuated objects.