A tank-based approach to impedance control with variable stiffness

Ferraguti, Federica; Secchi, Cristian; Fantuzzi, Cesare

doi:10.1109/icra.2013.6631284

Cited by 161 publications

(123 citation statements)

References 17 publications

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“…On the other hand, in surgical and rehabilitation scenarios, stiffness regulation plays an important role to ensure accuracy and safety in the presence of both preplanned target and interaction with unpredictable dynamic environments. An interesting method that allows us to reproduce a specific time-varying stiffness profile during needle insertion by preserving passivity is proposed in [16], while the implementation of safe constraints along a specific task or to limit the user to stay within a safe region is considered in [17]. These topics are also of interest in the applications where collaborative robots (Cobots) are employed [18].…”

Section: Related Workmentioning

confidence: 99%

Variable Impedance Control of Redundant Manipulators for Intuitive Human–Robot Physical Interaction

2015

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This paper presents an experimental study on human-robot comanipulation in the presence of kinematic redundancy. The objective of the work is to enhance the performance during human-robot physical interaction by combining Cartesian impedance modulation and redundancy resolution. Cartesian impedance control is employed to achieve a compliant behavior of the robot's end effector in response to forces exerted by the human operator. Different impedance modulation strategies, which take into account the human's behavior during the interaction, are selected with the support of a simulation study and then experimentally tested on a 7-degree-of-freedom KUKA LWR4. A comparative study to establish the most effective redundancy resolution strategy has been made by evaluating different solutions compatible with the considered task. The experiments have shown that the redundancy, when used to ensure a decoupled apparent inertia at the end effector, allows enlarging the stability region in the impedance parameters space and improving the performance. On the other hand, the variable impedance with a suitable modulation strategy for parameters' tuning outperforms the constant impedance, in the sense that it enhances the comfort perceived by humans during manual guidance and allows reaching a favorable compromise between accuracy and execution time.Index Terms-Force control, physical human-robot interaction, redundant robots. 1552-3098

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Section: Related Workmentioning

confidence: 99%

Variable Impedance Control of Redundant Manipulators for Intuitive Human–Robot Physical Interaction

2015

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“…To achieve this aim, we will exploit the port-Hamiltonian framework [8] for modeling the surgical robotic architecture and the concept of energy tanks [9], [10] that allows us to use the (virtual) energy circulating in the controlled system in a flexible and passivity preserving way. This paper extends [11], where a variable stiffness impedance control was provided, by designing a tankbased admittance control strategy where inertia, stiffness, and damping can all be passively changed. Furthermore, we will extend [10] by exploiting energy tanks not only for implementing a passive coupling between master and slave, but also for implementing a stable switch and position compensation in the transition between autonomous and teleoperated mode.…”

Section: Introductionmentioning

confidence: 96%

“…1) A novel tank-based time-varying admittance controller extending the earlier results of [11], allowing one to adapt the interactive behavior of the robot while preserving passivity. 2) A novel flexible and passivity-based teleoperation architecture that ensures a stable switch between autonomous and teleoperated modes and compensates for the kine-1 http://www.isur.eu/isur matic mismatch between the master and the slave (i.e., the surgical robot).…”

Section: Introductionmentioning

confidence: 99%

An Energy Tank-Based Interactive Control Architecture for Autonomous and Teleoperated Robotic Surgery

et al. 2015

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Introducing some form of autonomy in robotic surgery is being considered by the medical community to better exploit the potential of robots in the operating room. However, significant technological steps have to occur before even the smallest autonomous task is ready to be presented to the regulatory authorities. In this paper, we address the initial steps of this process, in particular the development of control concepts satisfying the basic safety requirements of robotic surgery, i.e., providing the robot with the necessary dexterity and a stable and smooth behavior of the surgical tool. Two specific situations are considered: the automatic adaptation to changing tissue stiffness and the transition from autonomous to teleoperated mode. These situations replicate real-life cases when the surgeon adapts the stiffness of her/his arm to penetrate tissues of different consistency and when, due to an unexpected event, the surgeon has to take over the control of the surgical robot. To address the first case, we propose a passivity-based interactive control architecture that allows us to implement stable time-varying interactive behaviors. For the second case, we present a two-layered bilateral control architecture that ensures a stable behavior during the transition between autonomy and teleoperation and, after the switch, limits the effect of initial mismatch between master and slave poses. The proposed solutions are validated in the realistic surgical scenario developed within the EU-funded I-SUR project, using a surgical robot prototype specifically designed for the autonomous execution of surgical tasks like the insertion of needles into the human body

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“…But the system passivity could not be ensured for time-varying control gains. In [9] a Cartesian impedance control was introduced based on the concept of energy tank [10,11], which can be applied to reproduce time-varying stiffness and therefore ensure stable behavior.…”

Section: Introductionmentioning

confidence: 99%

Passivity Based on Energy Tank for Cartesian Impedance Control of DLR Space Robots With Floating Base and Elastic Joints

2018

JCC

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Abstract. This paper presents a control structure for orbital servicing mission of CEASAR robotic arm developed by German Aerospace Center (DLR). In order to reduce mass the CEASAR arm is equipped with Harmonic-Drives with high ratio which unfortunately lead to high joint elasticity and high motor friction and have to be considered in controller design for successful manipulator in-orbit operations. Therefore, in this control structure, for high tracking control a cascaded position controller based on state feedback control structure with observer-based friction compensation and for safe interaction control with the environment a Cartesian impedance controller is used, which is designed based on using energy tank method to ensure passivity of the controlled system. The proposed control methods are very efficient and practicable. Furthermore, they are very robust with dynamic parameter uncertainties, coupling dynamics, and can simultaneously provide good results in term of the position accuracy and dynamic behavior. Simulation results validate practical effciency of the controllers.

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A tank-based approach to impedance control with variable stiffness

Cited by 161 publications

References 17 publications

Variable Impedance Control of Redundant Manipulators for Intuitive Human–Robot Physical Interaction

Variable Impedance Control of Redundant Manipulators for Intuitive Human–Robot Physical Interaction

An Energy Tank-Based Interactive Control Architecture for Autonomous and Teleoperated Robotic Surgery

Passivity Based on Energy Tank for Cartesian Impedance Control of DLR Space Robots With Floating Base and Elastic Joints

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