A Precise Real-Time Force-Aware Grasping System for Robust Aerial Manipulation

TL;DR

The paper tackles the problem of safe, force-aware aerial grasping on lightweight platforms, where conventional force sensors add mass and cost. It introduces a deformable quadrotor equipped with six magnetic soft tactile sensors and a geomagnetic-compensation scheme using a reference Hall sensor to provide real-time 3D force sensing onboard, coupled with an admittance-based control framework for precise force modulation. Key contributions include a compact tactile sensor array with a physics-based force decoupling model, geomagnetic compensation, and integrated position, attitude, and grasp control validated through balloon grasping and dynamic payload experiments. The work demonstrates practical, autonomous aerial manipulation of fragile objects without external infrastructure, paving the way for robust force-aware aerial manipulation in unstructured environments.

Abstract

Aerial manipulation requires force-aware capabilities to enable safe and effective grasping and physical interaction. Previous works often rely on heavy, expensive force sensors unsuitable for typical quadrotor platforms, or perform grasping without force feedback, risking damage to fragile objects. To address these limitations, we propose a novel force-aware grasping framework incorporating six low-cost, sensitive skin-like tactile sensors. We introduce a magnetic-based tactile sensing module that provides high-precision three-dimensional force measurements. We eliminate geomagnetic interference through a reference Hall sensor and simplify the calibration process compared to previous work. The proposed framework enables precise force-aware grasping control, allowing safe manipulation of fragile objects and real-time weight measurement of grasped items. The system is validated through comprehensive real-world experiments, including balloon grasping, dynamic load variation tests, and ablation studies, demonstrating its effectiveness in various aerial manipulation scenarios. Our approach achieves fully onboard operation without external motion capture systems, significantly enhancing the practicality of force-sensitive aerial manipulation. The supplementary video is available at: https://www.youtube.com/watch?v=mbcZkrJEf1I.

Figures (10)

• Figure 1: Grasping experiments. (a) Experimental setup for handling fragile toy blocks using our proposed magnetic soft tactile sensor, demonstrating gentle manipulation capability. (b-d) Deformable quadrotor sequence showing shrinkage-expansion-shrinkage states, with (c) exhibiting wider balloon deformation during expansion compared to shrunk configurations. (d) Measured grasping force from proposed tactile sensors, demonstrating force reduction during expansion and subsequent increase upon re-shrinkage.
• Figure 2: Hardware architecture. (a) Deformable quadrotor with six tactile sensors mounted on the inner wall. (b) Exploded view of the proposed tactile sensor showing its internal components and assembly. (c) Working principle schematic of the magnetic soft tactile sensor.
• Figure 3: System overview showing the integration of perception (force sensing and visual-inertial odometry), control (position, attitude, and grasp controllers), actuation (motor and servo system), and task execution (fragile object grasping and weight measurement capabilities).
• Figure 4: Sensor size comparison showing dimensions along all each axes with a coin for scale. The complete sensor weighs only 8 grams.
• Figure 5: Magnetic flux density measurements with/without geomagnetic compensation across different attitudes, showing reduced variation after compensation.