Kinematically-Decoupled Impedance Control for Fast Object Visual
  Servoing and Grasping on Quadruped Manipulators
Riccardo Parosi Mattia Risiglione Darwin G. Caldwell Claudio Semini Victor Barasuol
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.