Anuradha Ranasinghe

Anuradha Ranasinghe

B.Sc (special) in Physics,PhD in Robotics

Anuradha

Email-anuradha.ranasinghe@kcl.ac.uk View Anuradha Ranasinghe's profile on LinkedIn

I have been awarded my PhD in human-robot interactions on 1st September 2015.  (Thesis advisor: Dr. Thrishantha Nanayakkara).  My thesis focuses on identification of abstracted dynamics of haptic based human control policies and human responses in guiding/following using hard reins in low visibility conditions. The extracted haptic based guidance policies can be implemented on a robot to guide a human in low visibility conditions like indoor fire-fighting, disaster response, and search and rescue.

My work is funded by the UK Engineering and Physical Sciences Research Council (EPSRC) under the REINS project.

My work was featured in

1. EPSRC news release found here.

2. California based CBS Radio in a live interview found here.

Publications

Journals

  1. Ranasinghe, Anuradha, Jacques Penders, Prokar Dasgupta, Kaspar Althoefer, &  Thrishantha Nanayakkara, “Salient feature of haptic based guidance of people in low visibility environments using hard reins”,  IEEE Transactions on Systems, Man, and Cybernetics, Part B, 2015, DOI: 10.1109/TCYB.2015.2409772.  PDF
  2.  Ranasinghe, Anuradha,Prokar Dasgupta, Kaspar Althoefer, &  Thrishantha Nanayakkara, “Identification of Haptic Based Guiding Using Hard Reins”,   PLOS ONE journal, 2015, DOI: 10.1371/journal.pone.0132020.

Conference papers

  1. Ranasinghe, Anuradha, Jacques Penders, Prokar Dasgupta, Kaspar Althoefer, and Thrishantha Nanayakkara. “A two party haptic guidance controller via a hard rein.” In Intelligent Robots and Systems (IROS), 2013 IEEE/RSJ International Conference on, pp. 116-122. IEEE, 2013.
  2.  Ranasinghe, Anuradha, Kaspar Althoefer, Thrishantha Nanayakkara, Jacques Penders, and Prokar Dasgupta. “An Optimal State Dependent Haptic Guidance Controller via a Hard Rein.” In Systems, Man, and Cybernetics (SMC), 2013 IEEE International Conference on, pp. 2322-2327. IEEE, 2013. (This paper was short-listed  at  IEEE SMC2013 conference for the Franklin Taylor Memorial Award for the best paper and the Best Student Paper Award).
  3. Penders, J., Jones, P., Ranasinghe, Anuradha. & Nanayakkara, Thrishantha. . Enhancing       trust and confidence in human robot interaction. UKRE, Sheffield, 25-3, 2013.

Abstract

Ranasinghe, Anuradha, Althoefer, Kaspar., Penders, Jacques., Dasgupta, Prokar., & Nanayakkara, Thrishantha, “Differential involuntary recruitment of upper arm muscles determine direction dependent haptic perception of uniform external perturbations​”, Society of Neuroscience (SfN) 2014, Washington DC, 2014.

Papers under preparation:

  • Ranasinghe, Anuradha, Prokar Dasgupta, Kaspar Althoefer &  Thrishantha Nanayakkara, “Characteristics of voluntary movements in response to haptic commands without visual feedback”,  (under preparation to submit IEEE Transactions on Haptics: Special Issue on Haptics in Neuroscience)
  • Ranasinghe, Anuradha, Prokar Dasgupta, Kaspar Althoefer &  Thrishantha Nanayakkara, “How humans generalize cutaneous feedback”,  (under preparation to submit IEEE Transaction on Haptic)

Main findings

1. Human-human demonstrations of guiding showed that the guider uses on average, a 3rd order predictive policy to take current guiding actions based on predicted errors of the follower.

2. The follower uses on average, a 2nd order reactive policy to make current movements based on past commands given by the guider.

3. When the follower’s movements in response to tug forces generated by the guider is modeled using a virtual damped inertial model (virtual model because, followers movements largely comes from voluntary forces than due to tug forces of the guider), the variability of the damping coefficient reliably reflects the variability of the follower’s trust in the guider.

4. When control policy identified from human demonstration experiments was implemented on a planar 1-DoF robotic arm to perturb the blindfolded subjects’ most dominant arm in leftward/rightward directions, it was found that naive subjects elicit a 2nd order reactive behaviour similar to human demonstration experiments. However, trained subjects developed 2nd order predictive following behaviour.

5. Naive and trained subjects’ arm muscle activation is significantly different in leftward/rightward arm perturbation.

6. When humans are trained with primitive vibroactuator array patterns given in a sleeve worn in the arm, they can accurately recognize linear combinations of those patterns.

The experimental data can be found from here

 

Human-robot interactions

I implemented the closed loop feedback controller derived from HHI on a planner 1-DoF robotic arm to study the stability of the controller and variability of the movements when the visually impaired human arm perturbed by the robotic arm to convey the movement directions.

It was found that the guiding controller can bring human subjects into the desired angular position. Moreover, it was found that even though humans’ perception and behavior are same when the same controller is used to generate the arm perturbation from leftward/rightward directions,  however human muscle activation is different for leftward/rightward perturbations.

 

Design a wearable haptic based pattern feedback system

I have designed a wearable haptic based pattern feedback sleeve that has 7 vibrators to generate different intensity patterns. The aim of this  study to understand how humans generalize cutaneous feedback in different intensity patterns. The results provide new design guidelines to convey messages encoded in vibro-tactile patterns specially in scenarios where vision and audition are less reliable.

 

My broad future research interests

  1. Computational motor control
  2. Human robot interaction
  3. Haptics

Work Experience

  1. July 2007 – April 2012- Lecturer, Department of Electronics and Electrical, General Sir John Kotelawela Defence University, Sri Lanka.
  2. January 2006 –July 2007: Assistant Lecturer, Division of Electronics and Electrical, Institute of Technology,University of Moratuwa, Sri Lanka.
  3. February 2006 – December 2006: .Instructor, Division of Electronics and Electrical,  Institute of Technology,University of Moratuwa, Sri Lanka.
  4. April 2005 – January 2006: Demonstrator , Department of Physics, University of Sri Jayewardanepura, Sri Lanka.

Future Professional Objectives To become a Scientist to make useful contributions to the academic community and society while being an academically sound successful researcher.