Daphne Antotsiou

ISN Group · Electrical and Electronic Engineering · Imperial College London · South Kensington Campus · London SW7 2AZ · UK d.antotsiou17@imperial.ac.uk

I am currently a PhD candidate at Imperial College London and a member of the Imperial Computer Vision and Learning Lab. My main research interests are Machine Learning, Computer Vision, and Control. My main research topic is Imitation Learning in human-centric environments that involve object manipulation.


Timeline

Presented at ICRA

Philadelphia, USA

Presented the work titled "Modular Adaptive Policy Selection for Multi-Task Imitation Learning through Task Division" at ICRA.

May 2022

Presented at ICRA

Xi'an, China

Presented the work titled "Adversarial Imitation Learning with Trajectorial Augmentation and Correction" at ICRA.

June 2021

Presented at WiML

Montréal, Canada

Presented the work titled "Task Oriented Hand Motion Retargeting for Dexterous Manipulation Imitation" at the WiML workshop of NeurIPS. Was awarded the WiML travel grant.

December 2018

Presented at ECCV

Munich, Germany

Presented the work titled "Task Oriented Hand Motion Retargeting for Dexterous Manipulation Imitation" at the HANDS workshop of ECCV.

September 2018

PhD Candidate

Imperial College London, UK
September 2017 - Present

Research Software Engineer

Nordson DAGE, UK

Developed algorithms for Image Analysis and Automation on Manual X-ray Inspection Systems.

July 2015 - August 2017

MSc in Advanced Computing: Creative Technology

University of Bristol, UK

Thesis: Introducing Programming Concepts With WebGL.

2013 - 2014

Master's Diploma in Electrical and Computer Engineering

Aristotle University of Thessaloniki, Greece

Thesis: Detection and Classification of Gestures During the Eating Process Using Camera Feed.

2007 - 2013

Publications

Modular Adaptive Policy Selection for Multi-Task Imitation Learning through Task Division

ICRA

Abstract: Deep imitation learning requires many expert demonstrations, which can be hard to obtain, especially when many tasks are involved. However, different tasks often share similarities, so learning them jointly can greatly benefit them and alleviate the need for many demonstrations. But, joint multi-task learning often suffers from negative transfer, sharing information that should be task-specific. In this work, we introduce a method to perform multi-task imitation while allowing for task-specific features. This is done by using proto-policies as modules to divide the tasks into simple sub-behaviours that can be shared. The proto-policies operate in parallel and are adaptively chosen by a selector mechanism that is jointly trained with the modules. Experiments on different sets of tasks show that our method improves upon the accuracy of single agents, task-conditioned and multi-headed multi-task agents, as well as state-of-the-art meta learning agents. We also demonstrate its ability to autonomously divide the tasks into both shared and task-specific sub-behaviours.

May 2022

Adversarial Imitation Learning with Trajectorial Augmentation and Correction

ICRA

Abstract: Deep Imitation Learning requires a large number of expert demonstrations, which are not always easy to obtain, especially for complex tasks. A way to overcome this shortage of labels is through data augmentation. However, this cannot be easily applied to control tasks due to the sequential nature of the problem. In this work, we introduce a novel augmentation method which preserves the success of the augmented trajectories. To achieve this, we introduce a semi-supervised correction network that aims to correct distorted expert actions. To adequately test the abilities of the correction network, we develop an adversarial data augmented imitation architecture to train an imitation agent using synthetic experts. Additionally, we introduce a metric to measure diversity in trajectory datasets. Experiments show that our data augmentation strategy can improve accuracy and convergence time of adversarial imitation while preserving the diversity between the generated and real trajectories.

June 2021

Task Oriented Hand Motion Retargeting for Dexterous Manipulation Imitation

ECCV HANDS Workshop

Abstract: Human hand actions are quite complex, especially when they involve object manipulation, mainly due to the high dimensionality of the hand and the vast action space that entails. Imitating those actions with dexterous hand models involves different important and challenging steps: acquiring human hand information, retargeting it to a hand model, and learning a policy from acquired data. In this work, we capture the hand information by using a state-of-the-art hand pose estimator. We tackle the retargeting problem from the hand pose to a 29 DoF hand model by combining inverse kinematics and PSO with a task objective optimisation. This objective encourages the virtual hand to accomplish the manipulation task, relieving the effect of the estimator's noise and the domain gap. Our approach leads to a better success rate in the grasping task compared to our inverse kinematics baseline, allowing us to record successful human demonstrations. Furthermore, we used these demonstrations to learn a policy network using generative adversarial imitation learning (GAIL) that is able to autonomously grasp an object in the virtual space.

September 2018