Flying Calligrapher: Contact-Aware Motion and Force Planning and Control for Aerial Manipulation

TL;DR

This paper introduces a contact-aware motion and force planning and control framework for aerial manipulation, enabling drones to perform dynamic contact tasks like aerial calligraphy with high precision and flexibility.

Contribution

It presents a novel pipeline combining a contact-aware trajectory planner and a hybrid motion-force controller for dynamic aerial contact tasks.

Findings

Successfully drew diverse letters with an IoU of 0.59.

Achieved an end-effector position RMSE of 2.9 cm.

Achieved a force tracking RMSE of 0.7 N.

Abstract

Aerial manipulation has gained interest in completing high-altitude tasks that are challenging for human workers, such as contact inspection and defect detection, etc. Previous research has focused on maintaining static contact points or forces. This letter addresses a more general and dynamic task: simultaneously tracking time-varying contact force in the surface normal direction and motion trajectories on tangential surfaces. We propose a pipeline that includes a contact-aware trajectory planner to generate dynamically feasible trajectories, and a hybrid motion-force controller to track such trajectories. We demonstrate the approach in an aerial calligraphy task using a novel sponge pen design as the end-effector, whose stroke width is positively related to the contact force. Additionally, we develop a touchscreen interface for flexible user input. Experiments show our method can effectively draw diverse letters, achieving an IoU of 0.59 and an end-effector position (force) tracking RMSE of 2.9 cm (0.7 N). Website: https://xiaofeng-guo.github.io/flying-calligrapher/