Imperial College London

Dr Thrishantha Nanayakkara

Faculty of EngineeringDyson School of Design Engineering

Reader in Design Engineering and Robotics



+44 (0)20 7594 0965t.nanayakkara Website CV




RCS1 M229Dyson BuildingSouth Kensington Campus






BibTex format

author = {Nanayakkara, T and Jiang, A and Del, Rocío Armas Fernández M and Liu, H and Althoefer, K and Bimbo, J},
doi = {10.1109/TRO.2016.2549545},
journal = {IEEE Transactions on Robotics},
pages = {626--637},
title = {Stable grip control on soft objects with time-varying stiffness},
url = {},
volume = {32},
year = {2016}

RIS format (EndNote, RefMan)

AB - Humans can hold a live animal like a hamster without overly squeezing despite the fact that its soft body undergoes impedance and size variations due to breathing and wiggling. Although the exact nature of such biological motor controllers is not known, existing literature suggests that they maintain metastable interactions with dynamic objects based on prediction rather than reaction. Most robotic gripper controllers find such tasks very challenging mainly due to hard constraints imposed on the stability of closed-loop control and inadequate rates of convergence of adaptive controller parameters. This paper presents experimental and numerical simulation results of a control law based on a relaxed stability criterion of reducing the probability of failure to maintain a stable grip on a soft object that undergoes temporal variations in its internal impedance. The proposed controller uses only three parameters to interpret the probability of failure estimated using a history of grip forces to adjust the grip on the dynamic object. Here, we demonstrate that the proposed controller can maintain smooth and stable grip tightening and relaxing when the object undergoes random impedance variations, compared with a reactive controller that involves a similar number of controller parameters.
AU - Nanayakkara,T
AU - Jiang,A
AU - Del,Rocío Armas Fernández M
AU - Liu,H
AU - Althoefer,K
AU - Bimbo,J
DO - 10.1109/TRO.2016.2549545
EP - 637
PY - 2016///
SN - 1552-3098
SP - 626
TI - Stable grip control on soft objects with time-varying stiffness
T2 - IEEE Transactions on Robotics
UR -
UR -
VL - 32
ER -