3 research outputs found
Kinematically-Decoupled Impedance Control for Fast Object Visual Servoing and Grasping on Quadruped Manipulators
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.Comment: Accepted as contributed paper at 2023 IEEE/RSJ International
Conference on Intelligent Robots and Systems (IROS 2023
Identification of a Class of Hybrid Dynamical Systems
This paper presents a novel identification procedure for a class of hybrid dynamical systems. In particular, we consider hybrid dynamical systems which are single flowed and single jumped and whose flow and jump maps linearly depend on two sets of unknown parameters. A systematic way to determine whether the system is flowing or jumping is introduced and used to identify the unknown parameters by employing a linear recursive estimator. Simulations have been performed to prove the validity of the proposed methodology. Results proved the efficiency and accuracy of the developed identification procedure.ISSN:2405-896
Passivity-based control for haptic teleoperation of a legged manipulator in presence of time-delays
When dealing with the haptic teleoperation of multi-limbed mobile manipulators, the problem of mitigating the destabilizing effects arising from the communication link between the haptic device and the remote robot has not been properly addressed. In this work, we propose a passive control architecture to haptically teleoperate a legged mobile manipulator, while remaining stable in the presence of time delays and frequency mismatches in the master and slave controllers. At the master side, a discrete-time energy modulation of the control input is proposed. At the slave side, passivity constraints are included in an optimization-based whole-body controller to satisfy the energy limitations. A hybrid teleoperation scheme allows the human operator to remotely operate the robot’s endeffector while in stance mode, and its base velocity in locomotion mode. The resulting control architecture is demonstrated on a quadrupedal robot with an artificial delay added to the network