Kinematically-Decoupled Impedance Control for Fast Object Visual Servoing and Grasping on Quadruped Manipulators
This work addresses the challenge of precise object manipulation on dynamically moving quadruped robots, which is incremental as it builds on existing visual servoing and impedance control methods.
The authors tackled the problem of enabling quadruped manipulators to perform fast and robust visual servoing and grasping by proposing a control pipeline that combines kinematic decoupling and impedance control. They demonstrated its performance on a 140 kg robot, achieving robust tracking under dynamic conditions and external disturbances.
We propose a control pipeline for SAG (Searching, Approaching, and Grasping) of objects, based on a decoupled arm kinematic chain and impedance control, which integrates image-based visual servoing (IBVS). The kinematic decoupling allows for fast end-effector motions and recovery that leads to robust visual servoing. The whole approach and pipeline can be generalized for any mobile platform (wheeled or tracked vehicles), but is most suitable for dynamically moving quadruped manipulators thanks to their reactivity against disturbances. The compliance of the impedance controller makes the robot safer for interactions with humans and the environment. We demonstrate the performance and robustness of the proposed approach with various experiments on our 140 kg HyQReal quadruped robot equipped with a 7-DoF manipulator arm. The experiments consider dynamic locomotion, tracking under external disturbances, and fast motions of the target object.