183 results found
Moulin-Frier C, Fischer T, Petit M, et al., 2018, DAC-h3: A Proactive Robot Cognitive Architecture to Acquire and Express Knowledge About the World and the Self, IEEE TRANSACTIONS ON COGNITIVE AND DEVELOPMENTAL SYSTEMS, Vol: 10, Pages: 1005-1022, ISSN: 2379-8920
Chang HJ, Fischer T, Petit M, et al., 2018, Learning Kinematic Structure Correspondences Using Multi-Order Similarities, IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, Vol: 40, Pages: 2920-2934, ISSN: 0162-8828
Sarabia M, Young N, Canavan K, et al., 2018, Assistive robotic technology to combat social isolation in acute hospital settings, International Journal of Social Robotics, Vol: 10, Pages: 607-620, ISSN: 1875-4791
Social isolation in hospitals is a well established risk factor for complications such as cognitive decline and depression. Assistive robotic technology has the potential to combat this problem, but first it is critical to investigate how hospital patients react to this technology. In order to address this question, we introduced a remotely operated NAO humanoid robot which conversed, made jokes, played music, danced and exercised with patients in a London hospital. In total, 49 patients aged between 18–100 took part in the study, 7 of whom had dementia. Our results show that a majority of patients enjoyed their interaction with NAO. We also found that age and dementia significantly affect the interaction, whereas gender does not. These results indicate that hospital patients enjoy socialising with robots, opening new avenues for future research into the potential health benefits of a social robotic companion.
Nguyen P, Fischer T, Chang HJ, et al., 2018, Transferring visuomotor learning from simulation to the real world for robotics manipulation tasks, IEEE/RSJ International Conference on Intelligent Robots and Systems, Publisher: IEEE, Pages: 6667-6674, ISSN: 2153-0866
Hand-eye coordination is a requirement for many manipulation tasks including grasping and reaching. However, accurate hand-eye coordination has shown to be especially difficult to achieve in complex robots like the iCub humanoid. In this work, we solve the hand-eye coordination task using a visuomotor deep neural network predictor that estimates the arm's joint configuration given a stereo image pair of the arm and the underlying head configuration. As there are various unavoidable sources of sensing error on the physical robot, we train the predictor on images obtained from simulation. The images from simulation were modified to look realistic using an image-to-image translation approach. In various experiments, we first show that the visuomotor predictor provides accurate joint estimates of the iCub's hand in simulation. We then show that the predictor can be used to obtain the systematic error of the robot's joint measurements on the physical iCub robot. We demonstrate that a calibrator can be designed to automatically compensate this error. Finally, we validate that this enables accurate reaching of objects while circumventing manual fine-calibration of the robot.
Zolotas M, Elsdon J, Demiris Y, 2018, Head-mounted augmented reality for explainable robotic wheelchair assistance, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE
Robotic wheelchairs with built-in assistive fea-tures, such as shared control, are an emerging means ofproviding independent mobility to severely disabled individuals.However, patients often struggle to build a mental model oftheir wheelchair’s behaviour under different environmentalconditions. Motivated by the desire to help users bridge thisgap in perception, we propose a novel augmented realitysystem using a Microsoft Hololens as a head-mounted aid forwheelchair navigation. The system displays visual feedback tothe wearer as a way of explaining the underlying dynamicsof the wheelchair’s shared controller and its predicted futurestates. To investigate the influence of different interface designoptions, a pilot study was also conducted. We evaluated theacceptance rate and learning curve of an immersive wheelchairtraining regime, revealing preliminary insights into the potentialbeneficial and adverse nature of different augmented realitycues for assistive navigation. In particular, we demonstrate thatcare should be taken in the presentation of information, witheffort-reducing cues for augmented information acquisition (forexample, a rear-view display) being the most appreciated.
Goncalves Nunes U, Demiris Y, 2018, 3D motion segmentation of articulated rigid bodies based on RGB-D data, British Machine Vision Conference (BMVC 2018), Publisher: British Machine Vision Association (BMVA)
This paper addresses the problem of motion segmentation of articulated rigid bodiesfrom a single-view RGB-D data sequence. Current methods either perform dense motionsegmentation, and consequently are very computational demanding, or rely on sparse 2Dfeature points, which may not be sufficient to represent the entire scene. In this paper,we advocate the use of 3D semi-dense motion segmentation which also bridges somelimitations of standard 2D methods (e.g. background removal). We cast the 3D motionsegmentation problem into a subspace clustering problem, adding an adaptive spectralclustering that estimates the number of object rigid parts. The resultant method has fewparameters to adjust, takes less time than the temporal length of the scene and requiresno post-processing.
Chang HJ, Demiris Y, 2018, Highly Articulated Kinematic Structure Estimation Combining Motion and Skeleton Information, IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, Vol: 40, Pages: 2165-2179, ISSN: 0162-8828
Wang R, Amadori PV, Demiris Y, Real-Time Workload Classification during Driving using HyperNetworks
Classifying human cognitive states from behavioral and physiological signalsis a challenging problem with important applications in robotics. The problemis challenging due to the data variability among individual users, and sensorartefacts. In this work, we propose an end-to-end framework for real-timecognitive workload classification with mixture Hyper Long Short Term MemoryNetworks, a novel variant of HyperNetworks. Evaluating the proposed approach onan eye-gaze pattern dataset collected from simulated driving scenarios ofdifferent cognitive demands, we show that the proposed framework outperformsprevious baseline methods and achieves 83.9\% precision and 87.8\% recallduring test. We also demonstrate the merit of our proposed architecture byshowing improved performance over other LSTM-based methods.
Kucukyilmaz A, Demiris Y, 2018, Learning shared control by demonstration for personalized wheelchair assistance, IEEE Transactions on Haptics, Vol: 11, Pages: 431-442, ISSN: 1939-1412
An emerging research problem in assistive robotics is the design of methodologies that allow robots to provide personalized assistance to users. For this purpose, we present a method to learn shared control policies from demonstrations offered by a human assistant. We train a Gaussian process (GP) regression model to continuously regulate the level of assistance between the user and the robot, given the user's previous and current actions and the state of the environment. The assistance policy is learned after only a single human demonstration, i.e., in one-shot. Our technique is evaluated in a one-of-a-kind experimental study, where the machine-learned shared control policy is compared to human assistance. Our analyses show that our technique is successful in emulating human shared control, by matching the location and amount of offered assistance on different trajectories. We observed that the effort requirement of the users were comparable between human-robot and human-human settings. Under the learned policy, the jerkiness of the user's joystick movements dropped significantly, despite a significant increase in the jerkiness of the robot assistant's commands. In terms of performance, even though the robotic assistance increased task completion time, the average distance to obstacles stayed in similar ranges to human assistance.
Fischer T, Demiris Y, 2018, A computational model for embodied visual perspective taking: from physical movements to mental simulation, Vision Meets Cognition Workshop at CVPR 2018
To understand people and their intentions, humans have developed the ability to imagine their surroundings from another visual point of view. This cognitive ability is called perspective taking and has been shown to be essential in child development and social interactions. However, the precise cognitive mechanisms underlying perspective taking remain to be fully understood. Here we present a computa- tional model that implements perspective taking as a mental simulation of the physical movements required to step into the other point of view. The visual percept after each mental simulation step is estimated using a set of forward models. Based on our experimental results, we propose that a visual attention mechanism explains the response times reported in human visual perspective taking experiments. The model is also able to generate several testable predictions to be explored in further neurophysiological studies.
Choi J, Chang HJ, Fischer T, et al., 2018, Context-aware Deep Feature Compression for High-speed Visual Tracking
We propose a new context-aware correlation filter based tracking framework toachieve both high computational speed and state-of-the-art performance amongreal-time trackers. The major contribution to the high computational speed liesin the proposed deep feature compression that is achieved by a context-awarescheme utilizing multiple expert auto-encoders; a context in our frameworkrefers to the coarse category of the tracking target according to appearancepatterns. In the pre-training phase, one expert auto-encoder is trained percategory. In the tracking phase, the best expert auto-encoder is selected for agiven target, and only this auto-encoder is used. To achieve high trackingperformance with the compressed feature map, we introduce extrinsic denoisingprocesses and a new orthogonality loss term for pre-training and fine-tuning ofthe expert auto-encoders. We validate the proposed context-aware frameworkthrough a number of experiments, where our method achieves a comparableperformance to state-of-the-art trackers which cannot run in real-time, whilerunning at a significantly fast speed of over 100 fps.
Cully A, Demiris Y, 2018, Quality and Diversity Optimization: A Unifying Modular Framework, IEEE TRANSACTIONS ON EVOLUTIONARY COMPUTATION, Vol: 22, Pages: 245-259, ISSN: 1089-778X
Cully A, Demiris Y, Hierarchical Behavioral Repertoires with Unsupervised Descriptors
Enabling artificial agents to automatically learn complex, versatile andhigh-performing behaviors is a long-lasting challenge. This paper presents astep in this direction with hierarchical behavioral repertoires that stackseveral behavioral repertoires to generate sophisticated behaviors. Eachrepertoire of this architecture uses the lower repertoires to create complexbehaviors as sequences of simpler ones, while only the lowest repertoiredirectly controls the agent's movements. This paper also introduces a novelapproach to automatically define behavioral descriptors thanks to anunsupervised neural network that organizes the produced high-level behaviors.The experiments show that the proposed architecture enables a robot to learnhow to draw digits in an unsupervised manner after having learned to draw linesand arcs. Compared to traditional behavioral repertoires, the proposedarchitecture reduces the dimensionality of the optimization problems by ordersof magnitude and provides behaviors with a twice better fitness. Moreimportantly, it enables the transfer of knowledge between robots: ahierarchical repertoire evolved for a robotic arm to draw digits can betransferred to a humanoid robot by simply changing the lowest layer of thehierarchy. This enables the humanoid to draw digits although it has never beentrained for this task.
Fischer T, Puigbo J-Y, Camilleri D, et al., 2018, iCub-HRI: A Software Framework for Complex Human-Robot Interaction Scenarios on the iCub Humanoid Robot, FRONTIERS IN ROBOTICS AND AI, Vol: 5, ISSN: 2296-9144
Fischer T, Chang HJ, Demiris Y, 2018, RT-GENE: Real-time eye gaze estimation in natural environments, Pages: 339-357, ISSN: 0302-9743
© Springer Nature Switzerland AG 2018. In this work, we consider the problem of robust gaze estimation in natural environments. Large camera-to-subject distances and high variations in head pose and eye gaze angles are common in such environments. This leads to two main shortfalls in state-of-the-art methods for gaze estimation: hindered ground truth gaze annotation and diminished gaze estimation accuracy as image resolution decreases with distance. We first record a novel dataset of varied gaze and head pose images in a natural environment, addressing the issue of ground truth annotation by measuring head pose using a motion capture system and eye gaze using mobile eyetracking glasses. We apply semantic image inpainting to the area covered by the glasses to bridge the gap between training and testing images by removing the obtrusiveness of the glasses. We also present a new real-time algorithm involving appearance-based deep convolutional neural networks with increased capacity to cope with the diverse images in the new dataset. Experiments with this network architecture are conducted on a number of diverse eye-gaze datasets including our own, and in cross dataset evaluations. We demonstrate state-of-the-art performance in terms of estimation accuracy in all experiments, and the architecture performs well even on lower resolution images.
Elsdon J, Demiris Y, 2018, Augmented Reality for Feedback in a Shared Control Spraying Task, IEEE International Conference on Robotics and Automation (ICRA), Publisher: IEEE COMPUTER SOC, Pages: 1939-1946, ISSN: 1050-4729
Elsdon J, Demiris Y, 2017, Assisted painting of 3D structures using shared control with a hand-held robot, IEEE International Conference on Robotics and Automation, Publisher: IEEE, Pages: 4891-4897
Abstract— We present a shared control method of painting3D geometries, using a handheld robot which has a singleautonomously controlled degree of freedom. The user scansthe robot near to the desired painting location, the singlemovement axis moves the spray head to achieve the requiredpaint distribution. A simultaneous simulation of the sprayingprocedure is performed, giving an open loop approximationof the current state of the painting. An online prediction ofthe best path for the spray nozzle actuation is calculated ina receding horizon fashion. This is calculated by producing amap of the paint required in the 2D space defined by nozzleposition on the gantry and the time into the future. A directedgraph then extracts its edge weights from this paint density mapand Dijkstra’s algorithm is then used to find the candidate forthe most effective path. Due to the heavy parallelisation of thisapproach and the majority of the calculations taking place on aGPU we can run the prediction loop in 32.6ms for a predictionhorizon of 1 second, this approach is computationally efficient,outperforming a greedy algorithm. The path chosen by theproposed method on average chooses a path in the top 15%of all paths as calculated by exhaustive testing. This approachenables development of real time path planning for assistedspray painting onto complicated 3D geometries. This methodcould be applied to applications such as assistive painting forpeople with disabilities, or accurate placement of liquid whenlarge scale positioning of the head is too expensive.
Korkinof D, Demiris Y, 2017, Multi-task and multi-kernel Gaussian process dynamical systems, PATTERN RECOGNITION, Vol: 66, Pages: 190-201, ISSN: 0031-3203
Zambelli M, Demiris Y, 2017, Online Multimodal Ensemble Learning Using Self-Learned Sensorimotor Representations, IEEE TRANSACTIONS ON COGNITIVE AND DEVELOPMENTAL SYSTEMS, Vol: 9, Pages: 113-126, ISSN: 2379-8920
Georgiou T, Demiris Y, 2017, Adaptive user modelling in car racing games using behavioural and physiological data, USER MODELING AND USER-ADAPTED INTERACTION, Vol: 27, Pages: 267-311, ISSN: 0924-1868
Yoo Y, Yun S, Chang HJ, et al., 2017, Variational Autoencoded Regression: High Dimensional Regression of Visual Data on Complex Manifold, 30th IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), Publisher: IEEE, Pages: 2943-2952, ISSN: 1063-6919
Choi J, Chang HJ, Yun S, et al., 2017, Attentional Correlation Filter Network for Adaptive Visual Tracking, 30th IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), Publisher: IEEE, Pages: 4828-4837, ISSN: 1063-6919
Zhang F, Cully A, Demiris Y, 2017, Personalized Robot-assisted Dressing using User Modeling in Latent Spaces, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 3603-3610, ISSN: 2153-0858
Ros R, Oleari E, Pozzi C, et al., 2016, A Motivational Approach to Support Healthy Habits in Long-term Child-Robot Interaction, International Journal of Social Robotics, Vol: 8, Pages: 599-617, ISSN: 1875-4791
Petit M, Fischer T, Demiris Y, 2016, Towards the Emergence of Procedural Memories from Lifelong Multi-Modal Streaming Memories for Cognitive Robots, Workshop on Machine Learning Methods for High-Level Cognitive Capabilities in Robotics at IEEE/RSJ IROS
Various research topics are emerging as the demand for intelligent lifelong interactions between robot and humans increases. Among them, we can find the examination of persistent storage, the continuous unsupervised annotation of memories and the usage of data at high-frequency over long periods of time. We recently proposed a lifelong autobiographical memory architecture tackling some of these challenges, allowing the iCub humanoid robot to 1) create new memories for both actions that are self-executed and observed from humans, 2) continuously annotate these actions in an unsupervised manner, and 3) use reasoning modules to augment these memories a-posteriori. In this paper, we present a reasoning algorithm which generalises the robots’ understanding of actions by finding the point of commonalities with the former ones. In particular, we generated and labelled templates of pointing actions in different directions. This represents a first step towards the emergence of a procedural memory within a long-term autobiographical memory framework for robots.
Zambelli M, Fischer T, Petit M, et al., 2016, Towards Anchoring Self-Learned Representations to Those of Other Agents, Workshop on Bio-inspired Social Robot Learning in Home Scenarios IEEE/RSJ International Conference on Intelligent Robots and Systems, Publisher: Institute of Electrical and Electronics Engineers (IEEE)
In the future, robots will support humans in their every day activities. One particular challenge that robots will face is understanding and reasoning about the actions of other agents in order to cooperate effectively with humans. We propose to tackle this using a developmental framework, where the robot incrementally acquires knowledge, and in particular 1) self-learns a mapping between motor commands and sensory consequences, 2) rapidly acquires primitives and complex actions by verbal descriptions and instructions from a human partner, 3) discoverscorrespondences between the robots body and other articulated objects and agents, and 4) employs these correspondences to transfer the knowledge acquired from the robots point of view to the viewpoint of the other agent. We show that our approach requires very little a-priori knowledge to achieve imitation learning, to find correspondent body parts of humans, and allows taking the perspective of another agent. This represents a step towards the emergence of a mirror neuron like system based on self-learned representations.
Petit M, Fischer T, Demiris Y, 2016, Lifelong Augmentation of Multimodal Streaming Autobiographical Memories, IEEE TRANSACTIONS ON COGNITIVE AND DEVELOPMENTAL SYSTEMS, Vol: 8, Pages: 201-213, ISSN: 2379-8920
Gao Y, Chang HJ, Demiris Y, 2016, Personalised assistive dressing by humanoid robots using multi-modal information, Workshop on Human-Robot Interfaces for Enhanced Physical Interactions at ICRA
In this paper, we present an approach to enable a humanoid robot to provide personalised dressing assistance for human users using multi-modal information. A depth sensor is mounted on top of the robot to provide visual information, and the robot end effectors are equipped with force sensors to provide haptic information. We use visual information to model the movement range of human upper-body parts. The robot plans the dressing motions using the movement rangemodels and real-time human pose. During assistive dressing, the force sensors are used to detect external force resistances. We present how the robot locally adjusts its motions based on the detected forces. In the experiments we show that the robot can assist human to wear a sleeveless jacket while reacting tothe force resistances.
Ribes A, Cerquides J, Demiris Y, et al., 2016, Active Learning of Object and Body Models with Time Constraints on a Humanoid Robot, IEEE TRANSACTIONS ON COGNITIVE AND DEVELOPMENTAL SYSTEMS, Vol: 8, Pages: 26-41, ISSN: 2379-8920
Georgiou T, Demiris Y, 2016, Personalised Track Design in Car Racing Games, IEEE Conference on Computational Intelligence and Games (CIG), Publisher: IEEE, ISSN: 2325-4270
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