Necessary and Sufficient Conditions for the Passivity of Impedance Rendering With Velocity-Sourced Series Elastic Actuation

  title={Necessary and Sufficient Conditions for the Passivity of Impedance Rendering With Velocity-Sourced Series Elastic Actuation},
  author={Fatih Emre Tosun and Volkan Patoglu},
  journal={IEEE Transactions on Robotics},
Series elastic actuation (SEA) has become prevalent in applications involving physical human–robot interaction, as it provides considerable advantages over traditional stiff actuators in terms of stability robustness and force control fidelity. Several impedance control architectures have been proposed for SEA. Among these alternatives, the cascaded controller with an innermost velocity loop, an intermediate torque loop, and an outermost impedance loop is particularly favored for its simplicity… 
Stability and Transparency in Series Elastic Actuation: A Two-Port Analysis
This study extends the one-port passivity analyzes provided in the literature and provides the necessary and sufficient condition for two- port passivity of SEA under velocity-sourced impedance control, and derives non-conservative passivity bounds for a virtual coupler.
VnStylus: A Haptic Stylus With Variable Tip Compliance
This article presents the design, mathematical modeling, implementation, characterization and user evaluations of VnStylus, a stylus with hardware-based tip compliance modulation that is lightweight, low cost, and robust.
Novel fractional hybrid impedance control of series elastic muscle-tendon actuator
The main aim of this paper is to derive the dynamic simulation models of the SEM-TA, to develop a control architecture allowing for high-sensitive contact stress force control in three cases and to verify the simulation models and the proposed controller with experimental results.
Design, Implementation, and Evaluation of a Variable Stiffness Transradial Hand Prosthesis
The design, implementation, and experimental evaluation of a low-cost, customizable, easy-to-use transradial hand prosthesis capable of adapting its compliance and the control of the variable stiffness transradials is achieved by an sEMG based natural human-machine interface.
Simulation-based multi-criteria comparison of mono-articular and bi-articular exoskeletons during walking with and without load
A simulation-based multi-criteria design approach to systematically study the effect of different device kinematics and corresponding optimal assistive torque profiles under actuator saturation on the metabolic cost, muscle activation, and joint reaction forces of subjects walking under different loading conditions is presented.
Towards collaborative drilling with a cobot using admittance controller
A general methodology to design an admittance controller for a pHRI system is developed by considering the stability and transparency objectives and three different sets of parameters are selected from the allowable range and the effect of admittance controllers utilizing these parameter sets on the task performance is investigated.
Efficacy of Haptic Pedal Feel Compensation on Driving With Regenerative Braking
Experimental results indicate that pedal feel compensation can significantly decrease the hard braking instances, improving safety for both two-pedal cooperative braking and one-Pedal driving conditions.
A Computational Multicriteria Optimization Approach to Controller Design for Physical Human-Robot Interaction
A Pareto optimization framework is proposed, which jointly optimizes the stability robustness and transparency of a closed-loop pHRI system for a given interaction controller and enables a fair comparison among different interaction controllers.


Passivity constraints for the impedance control of series elastic actuators
Conservative passivity conditions are derived when a cascade-controlled series elastic actuator is used to haptically display different models of virtual impedance, useful for the selection of the control gains as well as for determining the ranges of renderable virtual impedance.
Series elasticity for free free-space motion for free
A haptic device featuring series elastic actuation is capable of providing both the low impedances required in free-space and the high impedance required for rendering stiff virtual walls.
Effects of discretization on the K-width of series elastic actuators
This paper proposes a hybrid model for a single degree-of-freedom (DoF) SEA based on prior hybrid models for rigid haptic systems, and derives a closed-form bound on the K-Width of SEAs that is a generalization of known constraints for both rigid haaptic systems and continuous time SEA models.
Complementary Stability and Loop Shaping for Improved Human–Robot Interaction
A loop-shaping design method is developed from a study of fundamental differences between interaction control and the more common servo problem, using a computational approach to search parameter spaces and displaying variations in performance as control parameters are adjusted.
Series elastic actuators
  • G. Pratt, M. Williamson
  • Engineering
    Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems. Human Robot Interaction and Cooperative Robots
  • 1995
It is proposed that for natural tasks, zero motion force bandwidth isn't everything, and incorporating series elasticity as a purposeful element within the actuator is a good idea.
Bounded-Impedance Absolute Stability of Bilateral Teleoperation Control Systems
A powerful 3D geometrical robust stability analysis method based on the notions of wave variables and scattering parameters that results in less conservative guaranteed stability conditions compared to the Llewellyn's criterion, promising a better compromise between stability and performance.
Compliant actuation of rehabilitation robots
It is concluded that compliant actuation and a lightweight exoskeleton provide effective means to accomplish the desired AAN behavior of a rehabilitation robot.
Design of a compact rotary series elastic actuator for improved actuation transparency and mechanical safety
The proposed cRSEA with a mechanical clutch is applied to develop a wearable robot for incomplete paraplegic patients and is optimally selected for the controllability, the input and output torque transmissibility, and the mechanical impedance.
Time domain passivity control of haptic interfaces
  • B. Hannaford, J. Ryu
  • Computer Science
    Proceedings 2001 ICRA. IEEE International Conference on Robotics and Automation (Cat. No.01CH37164)
  • 2001
An energy-based method is presented for controlling a haptic interface system to ensure stable contact under a wide variety of operating conditions and requires very little additional computation and does not require a dynamical model to be identified.