Imperial College London

Dr Thrishantha Nanayakkara

Faculty of EngineeringDyson School of Design Engineering

Reader in Design Engineering and Robotics
 
 
 
//

Contact

 

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

 
 
//

Location

 

RCS1 M229Dyson BuildingSouth Kensington Campus

//

Summary

 

Publications

Publication Type
Year
to

117 results found

Rijanto E, Sugiharto A, Utomo S, Rahmayanti R, Afrisal H, Nanayakkara Tet al., 2017, Trends in Robot Assisted Endovascular Catheterization Technology: A Review, International Conference on Robotics, Biomimetics, and Intelligent Computational Systems (Robionetics), Publisher: IEEE, Pages: 34-41

Conference paper

Abad S-A, Sornkarn N, Nanayakkara T, 2016, The role of morphological computation of the goat hoof in slip reduction, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 5599-5605, ISSN: 2153-0866

The remarkable ability of goats to maintain stability during climbing cliffs or trees provides a valuable opportunity to understand some of the secrets of stable legged locomotion on unstructured terrains. This paper, for the first time, presents analytical and experimental explanations as to how the morphological computation at the goat hoof makes a significant contribution to slip reduction on both smooth and rough surfaces. We conducted experiments using a laboratory made hoof and compared its dynamic behavior against a rounded foot. We recorded forces and position of the hoof to analyze the effect of its shape and the individual contributions from 3-joints in the hoof on the work required to slip. Results state that the work required to move the hoof is more than 3 times that required to move a rounded foot. Additionally, the variables in the transient state are affected not only by the number and type of joints but also by the interaction with the environment. These findings promote the development of new types of feet for robots for all terrain conditions with greater stability and less control complexity.

Conference paper

Wijesundera I, Halgamuge MN, Nirmalathas A, Nanayakkara Tet al., 2016, MFPT calculation for random walks in inhomogeneous networks, PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS, Vol: 462, Pages: 986-1002, ISSN: 0378-4371

Journal article

Sornkarn N, Nanayakkara T, 2016, Can a Soft Robotic Probe Use Stiffness Control Like a Human Finger to Improve Efficacy of Haptic Perception?, IEEE TRANSACTIONS ON HAPTICS, Vol: 10, Pages: 183-195, ISSN: 1939-1412

When humans are asked to palpate a soft tissue to locate a hard nodule, they regulate the stiffness, speed, and force of the finger during examination. If we understand the relationship between these behavioral variables and haptic information gain (transfer entropy) during manual probing, we can improve the efficacy of soft robotic probes for soft tissue palpation, such as in tumor localization in minimally invasive surgery. Here, we recorded the muscle co-contraction activity of the finger using EMG sensors to address the question as to whether joint stiffness control during manual palpation plays an important role in the haptic information gain. To address this question, we used a soft robotic probe with a controllable stiffness joint and a force sensor mounted at the base to represent the function of the tendon in a biological finger. Then, we trained a Markov chain using muscle co-contraction patterns of human subjects, and used it to control the stiffness of the soft robotic probe in the same soft tissue palpation task. The soft robotic experiments showed that haptic information gain about the depth of the hard nodule can be maximized by varying the internal stiffness of the soft probe.

Journal article

Konstantinova J, Cotugno G, Dasgupta P, Althoefer K, Nanayakkara Tet al., 2016, Autonomous robotic palpation of soft tissue using the modulation of applied force, IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics 2016, Publisher: IEEE, Pages: 323-328, ISSN: 2155-1774

Palpation or perception of tactile information from soft tissue organs during minimally invasive surgery is required to improve clinical outcomes. One of the methods of palpation includes examination using the modulation of applied force on the localized area. This paper presents a method of soft tissue autonomous palpation based on the mathematical model obtained from human tactile examination data using modulations of palpation force. Using a second order reactive auto-regressive model of applied force, a robotic probe with spherical indenter was controlled to examine silicone tissue phantoms containing artificial nodules. The results show that the autonomous palpation using the model abstracted from human demonstration can be used not only to detect embedded nodules, but also to enhance the stiffness perception compared to the static indentation of the probe.

Conference paper

Chathuranga DS, Wang Z, Noh Y, Nanayakkara T, Hirai Set al., 2016, Magnetic and Mechanical Modeling of a Soft Three-Axis Force Sensor, IEEE SENSORS JOURNAL, Vol: 16, Pages: 5298-5307, ISSN: 1530-437X

Journal article

Nanayakkara V, Ataka A, Venetsanos D, Duran O, Vitzilaios N, Nanayakkara T, Sahinkaya MNet al., 2016, Kinematic analysis of the human thumb with foldable palm, TAROS 2016, Publisher: Springer, Pages: 226-238, ISSN: 0302-9743

There have been numerous attempts to develop anthropomorphic robotic hands with varying levels of dexterous capabilities. However, these robotic hands often suffer from a lack of comprehensive understanding of the musculoskeletal behavior of the human thumb with integrated foldable palm. This paper proposes a novel kinematic model to analyze the importance of thumb-palm embodiment in grasping objects. The model is validated using human demonstrations for five precision grasp types across five human subjects. The model is used to find whether there are any co-activations among the thumb joint angles and muskuloskeletal parameters of the palm. In this paper we show that there are certain pairs of joints that show stronger linear relationships in the torque space than in joint angle space. These observations provide useful design guidelines to reduce control complexity in anthropomorphic robotic thumbs.

Conference paper

Sornkarn N, Nanayakkara T, 2016, The efficacy of interaction behavior and internal stiffness control for embodied information gain in haptic perception, IEEE International Conference on Robotics and Automation (ICRA) 2016, Publisher: IEEE, Pages: 2657-2662, ISSN: 1050-4729

Haptic perception in biological systems not only depends on the environmental conditions, but also on the behavioral state and the internal impedance of the embodiment because proprioceptive sensors are embedded in the muscle and tendons used for actuation. A simple example of such a phenomenon can be found when people are asked to palpate a soft tissue to identify a stiff-inclusion. People tend to perform a variety of palpation strategies depending on their previous knowledge and the desired information. Does this mean that the probing behavioral variables and internal muscle impedance parameters and their interaction with given environmental conditions play a role in the perception information gain during the estimation of soft tissue's properties? In this paper, we use a two-degree of freedom laboratory-made variable stiffness and indentation probe to investigate how the modulation of probing behavioral and internal stiffness variables can affect the accuracy of the depth estimation of stiff inclusions in artificial silicon phantom tissue using information gain metrics based on prior knowledge in form of memory primitives.

Conference paper

Sadati SMH, Shiva A, Ataka A, Naghibi SE, Walker ID, Althoefer K, Nanayakkara Tet al., 2016, A geometry deformation model for compound continuum manipulators with external loading, 2016 IEEE International Conference on Robotics and Automation, Pages: 4957-4962, ISSN: 1050-4729

© 2016 IEEE. The complexity of soft continuum manipulators with hybrid and tuneable structures poses a challenging task to achieve an inverse kinematics model which is both precise and computationally efficient for control and optimization purposes. In this paper, a new method based on the principle of virtual work and a geometry deformation approach is presented for the inverse kinematics model of the STIFF-FLOP arm which is a pneumatically actuated continuum manipulator. We propose a novel simplified and computationally efficient yet accurate analytical solution to analyse the static behaviour of a compound soft manipulator in the presence of external and body forces which is verified against experimental data, showing promising agreement with 10% mean error for planar movements. In the process, we present a new modelling approach for braided soft extensor actuators with no braid-surface relative slip constraint. For the first time, our model predicts a simple analytical solution for the cross section deformation which is essential to control soft manipulators with regional tunable stiffness structure.

Conference paper

Sornkarn N, Dasgupta P, Nanayakkara T, 2016, Morphological computation of haptic perception of a controllable stiffness probe, PLOS One, Vol: 11, ISSN: 1932-6203

When people are asked to palpate a novel soft object to discern its physical properties such as texture, elasticity, and even non-homogeneity, they not only regulate probing behaviors, but also the co-contraction level of antagonistic muscles to control the mechanical impedance of fingers. It is suspected that such behavior tries to enhance haptic perception by regulating the function of mechanoreceptors at different depths of the fingertips and proprioceptive sensors such as tendon and spindle sensors located in muscles. In this paper, we designed and fabricated a novel two-degree of freedom variable stiffness indentation probe to investigate whether the regulation of internal stiffness, indentation, and probe sweeping velocity (PSV) variables affect the accuracy of the depth estimation of stiff inclusions in an artificial silicon phantom using information gain metrics. Our experimental results provide new insights into not only the biological phenomena of haptic perception but also new opportunities to design and control soft robotic probes.

Journal article

Nanayakkara T, Jiang A, Del Rocío Armas Fernández M, Liu H, Althoefer K, Bimbo Jet al., 2016, Stable grip control on soft objects with time-varying stiffness, IEEE Transactions on Robotics, Vol: 32, Pages: 626-637, ISSN: 1552-3098

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.

Journal article

Wijesundera I, Halgamuge MN, Nanayakkara T, Nirmalathas Tet al., 2016, Natural Disasters, When Will They Reach Me?, Publisher: Springer, ISBN: 9789811011139

A complex natural process that occurs on earth is referred to as a natural disaster when it results in catastrophic life, economic and structural losses. Ranging from cyclone activity, bushfire, and tsunami waves to thunderstorms, earthquake and ...

Book

Cotugno G, Althoefer K, Nanayakkara T, 2016, The Role of the Thumb: Study of Finger Motion in Grasping and Reachability Space in Human and Robotic Hands, IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS, Vol: 47, Pages: 1061-1070, ISSN: 2168-2216

It is well acknowledged that the opposing thumb granted humans advanced manipulation capabilities. However, such a feature is not statistically quantified, and its representation is not formally addressed in robotics yet. This paper studies whether the displacement of the opposing thumb in humans is a determining factor for shaping the grip. Using statistical analysis of the variability of motion capture data from the GRASP database, we found that the displacement of the thumb plays a leading role on the shaping of the grip, independently from the specific object being grasped. Furthermore, we map and compare the reachability spaces of the human thumb and two state-of-the-art robotic thumbs: (1) the shadow and (2) the iCub hands. We conclude that the kinematics of robotic thumbs does not evenly span the reachability space of the human thumb, favoring precision grasping motions. Hence, our findings contribute to the discussion of the optimal modeling of robotic hands.

Journal article

Chathuranga DS, Wang Z, Noh Y, Nanayakkara T, Hirai Set al., 2016, A Soft Three Axis Force Sensor Useful for Robot Grippers, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 5556-5563

Conference paper

Li M, Konstantinova J, Secco EL, Jiang A, Liu H, Nanayakkara T, Seneviratne LD, Dasgupta P, Althoefer K, Wurdemann HAet al., 2015, Using visual cues to enhance haptic feedback for palpation on virtual model of soft tissue, MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, Vol: 53, Pages: 1177-1186, ISSN: 0140-0118

Journal article

Ranasinghe A, Dasgupta P, Althoefer K, Nanayakkara Tet al., 2015, Identification of Haptic Based Guiding Using Hard Reins, PLOS ONE, Vol: 10, ISSN: 1932-6203

Journal article

Ranasinghe A, Sornkarn N, Dasgupta P, Althoefer K, Penders J, Nanayakkara Tet al., 2015, Salient feature of haptic-ased guidance of people in low visibility environments using hard reins., IEEE Transactions on Cybernetics, Vol: 46, Pages: 568-579, ISSN: 2168-2267

This paper presents salient features of human-human interaction where one person with limited auditory and visual perception of the environment (a follower) is guided by an agent with full perceptual capabilities (a guider) via a hard rein along a given path. We investigate several salient features of the interaction between the guider and follower such as: 1) the order of an autoregressive (AR) control policy that maps states of the follower to actions of the guider; 2) how the guider may modulate the pulling force in response to the trust level of the follower; and 3) how learning may successively apportion the responsibility of control across different muscles of the guider. Based on experimental systems identification on human demonstrations from ten pairs of naive subjects, we show that guiders tend to adopt a third-order AR predictive control policy and followers tend to adopt second-order reactive control policy. Moreover, the extracted guider's control policy was implemented and validated by human-robot interaction experiments. By modeling the follower's dynamics with a time varying virtual damped inertial system, we found that it is the coefficient of virtual damping which is most sensitive to the trust level of the follower. We used these experimental insights to derive a novel controller that integrates an optimal order control policy with a push/pull force modulator in response to the trust level of the follower monitored using a time varying virtual damped inertial model.

Journal article

Gonzalez-Fierro M, Hernandez-Garcia D, Nanayakkara T, Balaguer Cet al., 2015, Behavior sequencing based on demonstrations: a case of a humanoid opening a door while walking, ADVANCED ROBOTICS, Vol: 29, Pages: 315-329, ISSN: 0169-1864

Journal article

Morland MFE, Althoefer K, Nanayakkara T, 2015, Novel method to form adaptive internal impedance profiles in walkers, 2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), Pages: 7764-7767, ISSN: 1557-170X

Journal article

Sadati SMH, Noh Y, Naghibi SE, Kaspar A, Nanayakkara Tet al., 2015, Stiffness Control of Soft Robotic Manipulator for Minimally Invasive Surgery (MIS) Using Scale Jamming, 8th International Conference on Intelligent Robotics and Applications (ICIRA), Publisher: SPRINGER-VERLAG BERLIN, Pages: 141-151, ISSN: 0302-9743

Conference paper

Chathuranga DS, Wang Z, Noh Y, Nanayakkara T, Hirai Set al., 2015, Disposable Soft 3 Axis Force Sensor for Biomedical Applications, 37th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC), Publisher: IEEE, Pages: 5521-5524, ISSN: 1557-170X

Conference paper

Chathuranga DS, Wang Z, Noh Y, Nanayakkara T, Hirai Set al., 2015, Robust Real time Material Classification Algorithm Using Soft Three Axis Tactile Sensor: Evaluation of the Algorithm, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 2093-2098, ISSN: 2153-0858

Conference paper

Li M, Luo S, Nanayakkara T, Seneviratne LD, Dasgupta P, Althoefer Ket al., 2014, Multi-fingered haptic palpation using pneumatic feedback actuators, SENSORS AND ACTUATORS A-PHYSICAL, Vol: 218, Pages: 132-141, ISSN: 0924-4247

Journal article

Jiang A, Ranzani T, Gerboni G, Lekstutyte L, Althoefer K, Dasgupta P, Nanayakkara Tet al., 2014, Robotic Granular Jamming: Does the Membrane Matter?, SOFT ROBOTICS, Vol: 1, Pages: 192-201, ISSN: 2169-5172

Journal article

Calinon S, Bruno D, Malekzadeh MS, Nanayakkara T, Caldwell DGet al., 2014, Human-robot skills transfer interfaces for a flexible surgical robot, COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE, Vol: 116, Pages: 81-96, ISSN: 0169-2607

Journal article

Konstantinova J, Jiang A, Althoefer K, Dasgupta P, Nanayakkara Tet al., 2014, Implementation of Tactile Sensing for Palpation in Robot-Assisted Minimally Invasive Surgery: A Review, IEEE SENSORS JOURNAL, Vol: 14, Pages: 2490-2501, ISSN: 1530-437X

Journal article

Gonzalez-Fierro M, Balaguer C, Swann N, Nanayakkara Tet al., 2014, Full-Body Postural Control of a Humanoid Robot with Both Imitation Learning and Skill Innovation, INTERNATIONAL JOURNAL OF HUMANOID ROBOTICS, Vol: 11, ISSN: 0219-8436

Journal article

Cianchetti M, Ranzani T, Gerboni G, Nanayakkara T, Althoefer K, Dasgupta P, Menciassi Aet al., 2014, Soft Robotics Technologies to Address Shortcomings in Today's Minimally Invasive Surgery: The STIFF-FLOP Approach, SOFT ROBOTICS, Vol: 1, Pages: 122-131, ISSN: 2169-5172

Journal article

Konstantinova J, Li M, Mehra G, Dasgupta P, Althoefer K, Nanayakkara Tet al., 2014, Behavioral Characteristics of Manual Palpation to Localize Hard Nodules in Soft Tissues, IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, Vol: 61, Pages: 1651-1659, ISSN: 0018-9294

Journal article

Sareh S, Jiang A, Faragasso A, Noh Y, Nanayakkara T, Dasgupta P, Seneviratne L, Wurdemann H, Althoefer Ket al., Bio-inspired tactile sensor sleeve for surgical soft manipulators, 2014 IEEE International Conference on Robotics and Automation (ICRA)

Conference paper

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: id=00933397&limit=30&person=true&page=2&respub-action=search.html