Towards Grasping with a Helicopter Platform: Landing Accuracy and Other Challenges

This paper presents recent research efforts to extend the functionality of unmanned aerial vehicles beyond passive observation to active interaction with and manipulation of objects. The archetypical aerial manipulation task — grasping objects during flight — is difficult due to the unstable dynamics of flying vehicles and limited positional accuracy currently demonstrated by hovering vehicles. Conventional rigid robot grippers require centimetre-level accuracy positioning to successfully grasp objects. Instead, we utilise passive mechanical compliance and adaptive underactuation in a gripper to allow for large positional displacements between a vehicle and target. We show that our approach allows a helicopter to reliably grasp objects, robust to the inherent inaccuracy of the aircraft’s landing precision. This paper begins by describing key challenges of the aerial manipulation task, then presents our approach to overcoming these challenges, and finally demonstrates experimental results showing successful grasping of a range of objects as a function of landing accuracy.