no code implementations • 25 Feb 2025 • Georgios Kamaras, Subramanian Ramamoorthy
We present an integrated (or end-to-end) framework for the Real2Sim2Real problem of manipulating deformable linear objects (DLOs) based on visual perception.
1 code implementation • 13 Dec 2024 • Jonghyuk Park, Alex Lascarides, Subramanian Ramamoorthy
In this paper, we offer a learning framework in which the agent's knowledge gaps are overcome through corrective feedback from a teacher whenever the agent explains its (incorrect) predictions.
no code implementations • 18 Nov 2024 • Shuai Li, Michael Burke, Subramanian Ramamoorthy, Juergen Gall
Motivated by the fact that in real-world scenarios object motion can be usually represented by a Markov process, we present a novel expectation maximization (EM) algorithm that trains a neural network to associate detections for tracking, without requiring prior knowledge of their temporal correspondences.
no code implementations • 13 Oct 2024 • Rimvydas Rubavicius, Antonio Valerio Miceli-Barone, Alex Lascarides, Subramanian Ramamoorthy
Cyber-physical systems like autonomous vehicles are tested in simulation before deployment, using domain-specific programs for scenario specification.
no code implementations • 27 Sep 2024 • Peter David Fagan, Subramanian Ramamoorthy
We validate the efficacy of our neural network layer on the task of reproducing human handwriting motions using the LASA Human Handwriting Dataset.
no code implementations • 26 Sep 2024 • Rimvydas Rubavicius, Peter David Fagan, Alex Lascarides, Subramanian Ramamoorthy
This paper addresses a challenging interactive task learning scenario we call rearrangement under unawareness: to manipulate a rigid-body environment in a context where the agent is unaware of a concept that is key to solving the instructed task.
no code implementations • 18 Aug 2024 • Chen Long-fei, Subramanian Ramamoorthy, Robert B Fisher
To address these challenges and improve the accuracy of human body motion estimation for healthcare purposes, we propose the OPPH operator designed to enhance current vision-based motion estimation methods.
no code implementations • 14 Jun 2024 • Chen Long-fei, Muhammad Ahmed Raza, Craig Innes, Subramanian Ramamoorthy, Robert B. Fisher
We simulate weakness in healthy subjects by having them perform physical exercise and observing the behavioral changes in their daily activities before and after workouts.
no code implementations • 21 Mar 2024 • Nikolaos Tsagkas, Jack Rome, Subramanian Ramamoorthy, Oisin Mac Aodha, Chris Xiaoxuan Lu
Precise manipulation that is generalizable across scenes and objects remains a persistent challenge in robotics.
1 code implementation • 13 Mar 2024 • Craig Innes, Subramanian Ramamoorthy
Two common issues arise when using existing techniques to produce this estimation: If violations occur rarely, simple Monte-Carlo sampling techniques can fail to produce efficient estimates; if simulation horizons are too long, importance sampling techniques (which learn proposal distributions from past simulations) can fail to converge.
no code implementations • 25 May 2023 • Anthony Knittel, Morris Antonello, John Redford, Subramanian Ramamoorthy
Typical predictors use the trajectory history to predict future motion, however in cases of motion initiation, motion in the trajectory may only be clearly visible after a delay, which can result in the pedestrian has entered the road area before an accurate prediction can be made.
1 code implementation • 5 May 2023 • Jonghyuk Park, Alex Lascarides, Subramanian Ramamoorthy
Interactive Task Learning (ITL) concerns learning about unforeseen domain concepts via natural interactions with human users.
1 code implementation • 20 Sep 2022 • Craig Innes, Subramanian Ramamoorthy
Testing black-box perceptual-control systems in simulation faces two difficulties.
no code implementations • 22 Jun 2022 • Aravinda Ramakrishnan Srinivasan, Yi-Shin Lin, Morris Antonello, Anthony Knittel, Mohamed Hasan, Majd Hawasly, John Redford, Subramanian Ramamoorthy, Matteo Leonetti, Jac Billington, Richard Romano, Gustav Markkula
Even though the models' RMSE value differed, all the models captured the kinematic-dependent merging behavior but struggled at varying degrees to capture the more nuanced courtesy lane change and highway lane change behavior.
no code implementations • 22 Jun 2022 • Dhaminda B. Abeywickrama, Amel Bennaceur, Greg Chance, Yiannis Demiris, Anastasia Kordoni, Mark Levine, Luke Moffat, Luc Moreau, Mohammad Reza Mousavi, Bashar Nuseibeh, Subramanian Ramamoorthy, Jan Oliver Ringert, James Wilson, Shane Windsor, Kerstin Eder
As autonomous systems (AS) increasingly become part of our daily lives, ensuring their trustworthiness is crucial.
1 code implementation • 21 May 2022 • Anthony L. Corso, Sydney M. Katz, Craig Innes, Xin Du, Subramanian Ramamoorthy, Mykel J. Kochenderfer
We formulate a risk function to quantify the effect of a given perceptual error on overall safety, and show how we can use it to design safer perception systems by including a risk-dependent term in the loss function and generating training data in risk-sensitive regions.
no code implementations • 25 Feb 2022 • Manu Lahariya, Craig Innes, Chris Develder, Subramanian Ramamoorthy
We simulate the task of using DEA to pull a coin along a surface with frictional contact, using FEM, and evaluate the physics-informed model for simulation, control, and inference.
1 code implementation • 12 Feb 2022 • Luca Viano, Yu-Ting Huang, Parameswaran Kamalaruban, Craig Innes, Subramanian Ramamoorthy, Adrian Weller
Imitation learning (IL) is a popular paradigm for training policies in robotic systems when specifying the reward function is difficult.
no code implementations • 27 Jan 2022 • Xin Du, Benedicte Legastelois, Bhargavi Ganesh, Ajitha Rajan, Hana Chockler, Vaishak Belle, Stuart Anderson, Subramanian Ramamoorthy
Robustness evaluations like our checklist will be crucial in future safety evaluations of visual perception modules, and be useful for a wide range of stakeholders including designers, deployers, and regulators involved in the certification of these systems.
no code implementations • 25 Oct 2021 • Allison McCarn Deiana, Nhan Tran, Joshua Agar, Michaela Blott, Giuseppe Di Guglielmo, Javier Duarte, Philip Harris, Scott Hauck, Mia Liu, Mark S. Neubauer, Jennifer Ngadiuba, Seda Ogrenci-Memik, Maurizio Pierini, Thea Aarrestad, Steffen Bahr, Jurgen Becker, Anne-Sophie Berthold, Richard J. Bonventre, Tomas E. Muller Bravo, Markus Diefenthaler, Zhen Dong, Nick Fritzsche, Amir Gholami, Ekaterina Govorkova, Kyle J Hazelwood, Christian Herwig, Babar Khan, Sehoon Kim, Thomas Klijnsma, Yaling Liu, Kin Ho Lo, Tri Nguyen, Gianantonio Pezzullo, Seyedramin Rasoulinezhad, Ryan A. Rivera, Kate Scholberg, Justin Selig, Sougata Sen, Dmitri Strukov, William Tang, Savannah Thais, Kai Lukas Unger, Ricardo Vilalta, Belinavon Krosigk, Thomas K. Warburton, Maria Acosta Flechas, Anthony Aportela, Thomas Calvet, Leonardo Cristella, Daniel Diaz, Caterina Doglioni, Maria Domenica Galati, Elham E Khoda, Farah Fahim, Davide Giri, Benjamin Hawks, Duc Hoang, Burt Holzman, Shih-Chieh Hsu, Sergo Jindariani, Iris Johnson, Raghav Kansal, Ryan Kastner, Erik Katsavounidis, Jeffrey Krupa, Pan Li, Sandeep Madireddy, Ethan Marx, Patrick McCormack, Andres Meza, Jovan Mitrevski, Mohammed Attia Mohammed, Farouk Mokhtar, Eric Moreno, Srishti Nagu, Rohin Narayan, Noah Palladino, Zhiqiang Que, Sang Eon Park, Subramanian Ramamoorthy, Dylan Rankin, Simon Rothman, ASHISH SHARMA, Sioni Summers, Pietro Vischia, Jean-Roch Vlimant, Olivia Weng
In this community review report, we discuss applications and techniques for fast machine learning (ML) in science -- the concept of integrating power ML methods into the real-time experimental data processing loop to accelerate scientific discovery.
no code implementations • 9 Oct 2021 • Jack Geary, Henry Gouk, Subramanian Ramamoorthy
Safe interaction between vehicles requires the ability to choose actions that reveal the preferences of the other vehicles.
no code implementations • 21 Sep 2021 • Xin Du, Subramanian Ramamoorthy, Wouter Duivesteijn, Jin Tian, Mykola Pechenizkiy
Specifically, we propose to leverage causal knowledge by regarding the distributional shifts in subpopulations and deployment environments as the results of interventions on the underlying system.
no code implementations • 6 Aug 2021 • Simón C. Smith, Subramanian Ramamoorthy
When the robot successfully executes the task, we use the attainment regions to gain insights into the limits of the controller, and its robustness.
no code implementations • 7 Jul 2021 • Todor Davchev, Sarah Bechtle, Subramanian Ramamoorthy, Franziska Meier
Inverse reinforcement learning is a paradigm motivated by the goal of learning general reward functions from demonstrated behaviours.
no code implementations • 14 May 2021 • Paola Ardón, Èric Pairet, Katrin S. Lohan, Subramanian Ramamoorthy, Ronald P. A. Petrick
Affordances describe the possibilities for an agent to perform actions with an object.
no code implementations • 2 May 2021 • Michael Burke, Subramanian Ramamoorthy
Data association is a fundamental component of effective multi-object tracking.
no code implementations • 1 Nov 2020 • Henry Pulver, Francisco Eiras, Ludovico Carozza, Majd Hawasly, Stefano V. Albrecht, Subramanian Ramamoorthy
In this paper, we present PILOT -- a planning framework that comprises an imitation neural network followed by an efficient optimiser that actively rectifies the network's plan, guaranteeing fulfilment of safety and comfort requirements.
no code implementations • 18 Sep 2020 • Simón C. Smith, Subramanian Ramamoorthy
', motivated by applications in robot control.
no code implementations • 18 Aug 2020 • Todor Davchev, Kevin Sebastian Luck, Michael Burke, Franziska Meier, Stefan Schaal, Subramanian Ramamoorthy
Dynamic Movement Primitives (DMP) are a popular way of extracting such policies through behaviour cloning (BC) but can struggle in the context of insertion.
1 code implementation • 3 Aug 2020 • Michael Burke, Kartic Subr, Subramanian Ramamoorthy
Humans can easily reason about the sequence of high level actions needed to complete tasks, but it is particularly difficult to instil this ability in robots trained from relatively few examples.
no code implementations • 23 Jul 2020 • Simón C. Smith, Subramanian Ramamoorthy
The system induces a controller program by learning from immersive demonstrations using sequential importance sampling.
no code implementations • ICLR 2021 • Yordan Hristov, Subramanian Ramamoorthy
We show that such alignment is best achieved through the use of labels from the end user, in an appropriately restricted vocabulary, in contrast to the conventional approach of the designer picking a prior over the latent variables.
no code implementations • 15 Apr 2020 • Paola Ardón, Èric Pairet, Katrin S. Lohan, Subramanian Ramamoorthy, Ronald P. A. Petrick
Affordances are key attributes of what must be perceived by an autonomous robotic agent in order to effectively interact with novel objects.
Robotics
2 code implementations • 6 Feb 2020 • Stefano V. Albrecht, Cillian Brewitt, John Wilhelm, Francisco Eiras, Mihai Dobre, Subramanian Ramamoorthy
The ability to predict the intentions and driving trajectories of other vehicles is a key problem for autonomous driving.
Robotics
no code implementations • 4 Feb 2020 • Michael Burke, Katie Lu, Daniel Angelov, Artūras Straižys, Craig Innes, Kartic Subr, Subramanian Ramamoorthy
This work considers the inverse problem, where the goal of the task is unknown, and a reward function needs to be inferred from exploratory example demonstrations provided by a demonstrator, for use in a downstream informative path-planning policy.
no code implementations • 3 Feb 2020 • Craig Innes, Subramanian Ramamoorthy
We also implement our system on a PR-2 robot to show how a demonstrator can start with an initial (sub-optimal) demonstration, then interactively improve task success by including additional specifications enforced with our differentiable LTL loss.
1 code implementation • 18 Dec 2019 • Emmanuel Kahembwe, Subramanian Ramamoorthy
This work presents an analysis of the discriminators used in Generative Adversarial Networks (GANs) for Video.
1 code implementation • 29 Nov 2019 • Todor Davchev, Michael Burke, Subramanian Ramamoorthy
Context plays a significant role in the generation of motion for dynamic agents in interactive environments.
no code implementations • 31 Jul 2019 • Yordan Hristov, Daniel Angelov, Michael Burke, Alex Lascarides, Subramanian Ramamoorthy
Learning from demonstration is an effective method for human users to instruct desired robot behaviour.
no code implementations • 23 Jul 2019 • Stefano V. Albrecht, Jacob W. Crandall, Subramanian Ramamoorthy
Past research has studied two approaches to utilise predefined policy sets in repeated interactions: as experts, to dictate our own actions, and as types, to characterise the behaviour of other agents.
no code implementations • 22 Jul 2019 • Stefano V. Albrecht, Subramanian Ramamoorthy
In this work, we empirically evaluate five MAL algorithms, representing major approaches to multiagent learning but originally developed with the homogeneous setting in mind, to understand their behaviour in a set of ad hoc team problems.
no code implementations • 18 Jul 2019 • Daniel Angelov, Yordan Hristov, Michael Burke, Subramanian Ramamoorthy
Robot control policies for temporally extended and sequenced tasks are often characterized by discontinuous switches between different local dynamics.
no code implementations • 15 Jul 2019 • Stefano V. Albrecht, Subramanian Ramamoorthy
In this paper, we provide theoretical guidance on two central design parameters of this method: Firstly, it is important that the user choose a posterior which can learn the true distribution of latent types, as otherwise suboptimal actions may be chosen.
no code implementations • 10 Jul 2019 • Stefano V. Albrecht, Jacob W. Crandall, Subramanian Ramamoorthy
To address this problem, researchers have studied learning algorithms which compute posterior beliefs over a hypothesised set of policies, based on the observed actions of the other agents.
no code implementations • 10 Jul 2019 • Stefano V. Albrecht, Subramanian Ramamoorthy
Belief filtering in DBNs is the task of inferring the belief state (i. e. the probability distribution over process states) based on incomplete and uncertain observations.
1 code implementation • 9 Jul 2019 • Michael Burke, Yordan Hristov, Subramanian Ramamoorthy
This paper introduces switching density networks, which rely on a categorical reparametrisation for hybrid system identification.
no code implementations • 24 Jun 2019 • Daniel Angelov, Yordan Hristov, Subramanian Ramamoorthy
Many realistic robotics tasks are best solved compositionally, through control architectures that sequentially invoke primitives and achieve error correction through the use of loops and conditionals taking the system back to alternative earlier states.
Robotics
no code implementations • 24 Jun 2019 • Paola Ardón, Èric Pairet, Ronald P. A. Petrick, Subramanian Ramamoorthy, Katrin S. Lohan
We use Markov Logic Networks to build a knowledge base graph representation to obtain a probability distribution of grasp affordances for an object.
Robotics
no code implementations • 17 Jun 2019 • Adeel Mufti, Svetlin Penkov, Subramanian Ramamoorthy
The agent improves its policy in simulations generated by the DNC model and rolls out the policy to the live environment, collecting experiences in new portions or tasks of the environment for further learning.
Model-based Reinforcement Learning
reinforcement-learning
+2
no code implementations • 7 May 2019 • Todor Davchev, Timos Korres, Stathi Fotiadis, Nick Antonopoulos, Subramanian Ramamoorthy
Specifically, we study the effects of using robust optimisation in the source and target networks.
no code implementations • ICLR 2019 • Svetlin Penkov, Subramanian Ramamoorthy
We present the perceptor gradients algorithm -- a novel approach to learning symbolic representations based on the idea of decomposing an agent's policy into i) a perceptor network extracting symbols from raw observation data and ii) a task encoding program which maps the input symbols to output actions.
no code implementations • 4 Mar 2019 • Daniel Angelov, Yordan Hristov, Subramanian Ramamoorthy
In this work we show that it is possible to learn a generative model for distinct user behavioral types, extracted from human demonstrations, by enforcing clustering of preferred task solutions within the latent space.
no code implementations • 27 Feb 2019 • Michael Burke, Svetlin Penkov, Subramanian Ramamoorthy
This work introduces an approach to learning hybrid systems from demonstrations, with an emphasis on extracting models that are explicitly verifiable and easily interpreted by robot operators.
no code implementations • 10 Feb 2019 • Stavros Gerakaris, Subramanian Ramamoorthy
We address this problem using the Harsanyi-Bellman Ad Hoc Coordination (HBA) algorithm, which conceptualises this interaction in terms of a Stochastic Bayesian Game and arrives at optimal actions by best responding with respect to probabilistic beliefs maintained over a candidate set of opponent behaviour profiles.
no code implementations • 17 Jul 2018 • Yordan Hristov, Alex Lascarides, Subramanian Ramamoorthy
Effective human-robot interaction, such as in robot learning from human demonstration, requires the learning agent to be able to ground abstract concepts (such as those contained within instructions) in a corresponding high-dimensional sensory input stream from the world.
no code implementations • 6 Mar 2018 • Helen Hastie, Katrin Lohan, Mike Chantler, David A. Robb, Subramanian Ramamoorthy, Ron Petrick, Sethu Vijayakumar, David Lane
To enable this to happen, the remote operator will need a high level of situation awareness and key to this is the transparency of what the autonomous systems are doing and why.
no code implementations • 10 Jan 2018 • Craig Innes, Alex Lascarides, Stefano V. Albrecht, Subramanian Ramamoorthy, Benjamin Rosman
Methods for learning optimal policies in autonomous agents often assume that the way the domain is conceptualised---its possible states and actions and their causal structure---is known in advance and does not change during learning.
no code implementations • 26 Jul 2017 • Svetlin Penkov, Subramanian Ramamoorthy
Explaining and reasoning about processes which underlie observed black-box phenomena enables the discovery of causal mechanisms, derivation of suitable abstract representations and the formulation of more robust predictions.
no code implementations • WS 2017 • Yordan Hristov, Svetlin Penkov, Alex Lascarides, Subramanian Ramamoorthy
As robots begin to cohabit with humans in semi-structured environments, the need arises to understand instructions involving rich variability---for instance, learning to ground symbols in the physical world.
no code implementations • 23 May 2017 • Svetlin Penkov, Subramanian Ramamoorthy
Explaining and reasoning about processes which underlie observed black-box phenomena enables the discovery of causal mechanisms, derivation of suitable abstract representations and the formulation of more robust predictions.
no code implementations • 25 Jul 2016 • Majd Hawasly, Florian T. Pokorny, Subramanian Ramamoorthy
Autonomous robots operating in dynamic environments must maintain beliefs over a hypothesis space that is rich enough to represent the activities of interest at different scales.
no code implementations • 28 Jul 2015 • Stefano V. Albrecht, Jacob W. Crandall, Subramanian Ramamoorthy
The idea is to hypothesise a set of types, each specifying a possible behaviour for the other agents, and to plan our own actions with respect to those types which we believe are most likely, given the observed actions of the agents.
no code implementations • 3 Jun 2015 • Stefano V. Albrecht, Subramanian Ramamoorthy
Based on this model, we derive a solution, called Harsanyi-Bellman Ad Hoc Coordination (HBA), which utilises the concept of Bayesian Nash equilibrium in a planning procedure to find optimal actions in the sense of Bellman optimal control.
no code implementations • 1 May 2015 • Benjamin Rosman, Majd Hawasly, Subramanian Ramamoorthy
We formalise the problem of policy reuse, and present an algorithm for efficiently responding to a novel task instance by reusing a policy from the library of existing policies, where the choice is based on observed 'signals' which correlate to policy performance.
no code implementations • 30 Jan 2014 • Stefano V. Albrecht, Subramanian Ramamoorthy
Furthermore, we demonstrate how passivity occurs naturally in a complex system such as a multi-robot warehouse, and how PSBF can exploit this to accelerate the filtering task.
no code implementations • 15 Nov 2013 • M. M. Hassan Mahmud, Majd Hawasly, Benjamin Rosman, Subramanian Ramamoorthy
The source subset forms an `$\epsilon$-net' over the original set of MDPs, in the sense that for each previous MDP $M_p$, there is a source $M^s$ whose optimal policy has $<\epsilon$ regret in $M_p$.