Aude Billard

Aude Billard
École Polytechnique Fédérale de Lausanne | EPFL

About

824
Publications
98,225
Reads
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21,022
Citations
Citations since 2017
62 Research Items
9268 Citations
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201720182019202020212022202305001,0001,500
201720182019202020212022202305001,0001,500
201720182019202020212022202305001,0001,500
Introduction
Skills and Expertise

Publications

Publications (824)
Article
Full-text available
Objective: The limited functionality of hand prostheses remains one of the main reasons behind the lack of its wide adoption by amputees. Indeed, while commercial prostheses can perform a reasonable number of grasps, they are often inadequate for manipulating the object once in hand. This lack of dexterity drastically restricts the utility of pros...
Preprint
Full-text available
In robotics motion is often described from an external perspective, i.e., we give information on the obstacle motion in a mathematical manner with respect to a specific (often inertial) reference frame. In the current work, we propose to describe the robotic motion with respect to the robot itself. Similar to how we give instructions to each other...
Article
Full-text available
This article presents a closed-form approach to constraining a flow within a given volume and around objects. The flow is guaranteed to converge and to stop at a single fixed point. The obstacle avoidance problem is inverted to enforce that the flow remains enclosed within a volume defined by a polygonal surface. We formally guarantee that such a f...
Preprint
Full-text available
Humans are remarkable at navigating and moving through dynamic and complex spaces, such as crowded streets. For robots to do the same, it is crucial that they are endowed with highly reactive obstacle avoidance robust to partial and poor sensing. We address the issue of enabling obstacle avoidance based on sparse and asynchronous perception. The pr...
Article
State-dependent dynamical systems (DSs) offer adaptivity, reactivity, and robustness to perturbations in motion planning and physical human–robot interaction tasks. Learning DS-based motion plans from non-linear reference trajectories is an active research area in robotics. Most approaches focus on learning DSs that can (i) accurately mimic the dem...
Article
Full-text available
In this paper, we present an approach for learning a neural implicit signed distance function expressed in joint space coordinates, that efficiently computes distance-to-collisions for arbitrary robotic manipulator configurations. Computing such distances is a long standing problem in robotics as approximate representations of the robot and environ...
Article
Full-text available
Humans excel at navigating and moving through dynamic and complex spaces, such as crowded streets. For robots to do the same, it is crucial that they are endowed with highly reactive obstacle avoidance which is adept at partial and poor sensing. We address the issue of enabling obstacle avoidance based on sparse and asynchronous perception. The pro...
Article
Full-text available
Robotic assistance via motorized robotic arm manipulators can be of valuable assistance to individuals with upper-limb motor disabilities. Brain-computer interfaces (BCI) offer an intuitive means to control such assistive robotic manipulators. However, BCI performance may vary due to the non-stationary nature of the electroencephalogram (EEG) signa...
Article
In industrial or surgical settings, to achieve many tasks successfully, at least two people are needed. To this end, robotic assistance could be used to enable a single person to perform such tasks alone, with the help of robots through direct, shared, or autonomous control. We are interested in four-arm manipulation scenarios, where both feet are...
Article
Full-text available
In this work, we propose a real-time self-collision avoidance approach for whole-body humanoid robot control. To achieve this, we learn the feasible regions of control in the humanoid's joint space as smooth self-collision boundary functions. Collision-free motions are generated online by treating the learned boundary functions as constraints in a...
Article
Full-text available
A seamless interaction requires two robotic behaviors: the leader role where the robot rejects the external perturbations and focuses on the autonomous execution of the task, and the follower role where the robot ignores the task and complies with human intentional forces. The goal of this work is to provide (1) a unified robotic architecture to pr...
Article
We propose a novel controller for powered prosthetic arms, where fused EMG and gaze data predict the desired end-point for a full arm prosthesis, which could drive the forward motion of individual joints. We recorded EMG, gaze, and motiontracking during pick-and-place trials with 7 able-bodied subjects. Subjects positioned an object above a random...
Conference Paper
Full-text available
Many manipulation tasks require coordinated motions for arm and fingers. Complexity increases when the task requires to control for the force at contact against a non-flat surface; This becomes even more challenging when this contact is done on a human. All these challenges are regrouped when one, for instance, massages a human limb. When massaging...
Article
Full-text available
Objective: Translational studies on motor control and neurological disorders require detailed monitoring of sensorimotor components of natural limb movements in relevant animal models. However, available experimental tools do not provide a sufficiently rich repertoire of behavioral signals. Here, we developed a robotic platform that enables the mo...
Preprint
We seek to augment human manipulation by enabling humans to control two robotic arms in addition to their natural arms using their feet. Thereby, the hands are free to perform tasks of high dexterity, while the feet-controlled arms perform tasks requiring lower dexterity, such as supporting a load. The robotic arms are tele-operated through two foo...
Article
Full-text available
Myoelectric prostheses allow users to recover lost functionality by controlling a robotic device with their remaining muscle activity. Such commercial devices can give users a high level of autonomy, but still do not approach the dexterity of the intact human hand. Here we present a method to control a robotic hand, shared between user intention an...
Conference Paper
Full-text available
Assistive robotics aims to design physically collab-orative robots which are able to help human partners with cumbersome tasks; for instance, lifting a heavy plank/guard and inserting it into a frame at the ceiling. To reduce human load-share, it is expected from the robot to perform such tasks in coordination with the human partner. Uncertainty of...
Conference Paper
Full-text available
Many tasks require the robot to enter in contact with surfaces, be it to take support, to polish or to grasp an object. It is crucial that the robot controls forces both upon making contact and while in contact. While many solutions exist to control for contact, none offer the required robustness to adapt to real-world uncertainties, such as sudden...
Article
Full-text available
Hand it to you Our ability to grab, hold, and manipulate objects involves our dexterous hands, our sense of touch, and feedback from our eyes and muscles that allows us to maintain a controlled grip. Billard and Kragic review the progress made in robotics to emulate these functions. Systems have developed from simple, pinching grippers operating in...
Preprint
Full-text available
Translational studies on motor control and neurological disorders require detailed monitoring of sensorimotor components of natural limb movements in relevant animal models. However, available experimental tools do not provide a sufficiently rich repertoire of behavioral signals. Here, we developed a robotic platform that enables the monitoring of...
Article
Full-text available
The goal of this work is to enable robots to intelligently and compliantly adapt their motions to the intention of a human during physical Human-Robot Interaction (pHRI) in a multi-task setting. We employ a class of parameterized dynamical systems that allows for smooth and adaptive transitions between encoded tasks. To comply with human intention,...
Article
Full-text available
This paper contributes a novel framework to efficiently learn cost-to-go function representations for robotic tasks with latent modes. The proposed approach relies on the principle behind ensemble methods, where improved performance is obtained by aggregating a group of simple models, each of which can be efficiently learnedq. The maximum-entropy a...
Conference Paper
Cognitive information has been exploited in noninvasive Brain Computer Interface (BCI) scenarios to provide autonomous external agents with additional information. In this context, Error-related potentials (ErrPs), temporal deflections in electroencephalogram (EEG) signals when humans perceive erroneous actions, have been exploited to teach correct...
Article
Full-text available
This paper presents a closed-form approach to obstacle avoidance for multiple moving convex and star-shaped concave obstacles. The method takes inspiration in harmonic-potential fields. It inherits the convergence properties of harmonic potentials. We prove impenetrability of the obstacle's hull and asymptotic stability at a final goal location, us...
Article
Full-text available
Language acquisition theories classically distinguish passive language understanding from active language production. However, recent findings show that brain areas such as Broca's region are shared in language understanding and production. Furthermore, these areas are also implicated in understanding and producing goal-oriented actions. These obse...
Conference Paper
Full-text available
In this work, we present an adaptive motion planning approach for impedance-controlled robots to modify their tasks based on human physical interactions. We use a class of parameterized time-independent dynamical systems for motion generation where the modulation of such parameters allows for motion flexibility. To adapt to human interactions, we u...
Article
Full-text available
Background: Active upper-limb prostheses are used to restore important hand functionalities, such as grasping. In conventional approaches, a pattern recognition system is trained over a number of static grasping gestures. However, training a classifier in a static position results in lower classification accuracy when performing dynamic motions, s...
Article
Full-text available
Gripper adaptability to handle objects of different size and geometry brings high flexibility to manipulation. Gripping flat, round, or narrow objects poses challenges to even the most sophisticated robotic grippers. Among various gripper technologies, the vacuum suction grippers provide design simplicity, yet versatility at low cost, however, thei...
Article
In this paper, we propose an asymptotically stable joint-space dynamical system (DS) that captures desired behaviors in joint-space while converging towards a task-space attractor in both position and orientation. To encode joint-space behaviors while meeting the stability criteria, we propose a DS constructed as a Linear Parameter Varying (LPV) sy...
Article
Many daily life tasks require precise control when making contact with surfaces. Ensuring a smooth transition from free motion to contact is crucial as incurring a large impact force may lead to unstable contact with the robot bouncing on the surface, i.e. chattering. Stabilizing the forces at contact is not possible as the impact lasts less than a...
Article
In this paper we focus on extracting a parametrization of asymmetrical bimanual tasks from human demonstration. Two arms coordinate while being in physical contact and fulfilling complementary aspects of the task: one arm is mostly assistive while the other performs active manipulation. Such a task can be executed either autonomously by a bimanual...
Article
Full-text available
Coordination is essential in the design of dynamic control strategies for multi-arm robotic systems. Given the complexity of the task and dexterity of the system, coordination constraints can emerge from different levels of planning and control. Primarily, one must consider task-space coordination, where the robots must coordinate with each other,...
Article
Full-text available
The aim of the present study was to explore how schizophrenia patients attribute mind to a humanoid robot compared to healthy individuals. Results show that if there is no doubt that robots could assist schizophrenia patients in a variety of their living daily tasks, mind perception and other social cognition deficits could negatively impact their...
Article
Full-text available
An important challenge when using reinforcement learning for learning motions in robotics is the choice of parameterization for the policy. We use Gaussian Mixture Regression to extract a parameterization with relevant non-linear features from a set of demonstrations of a motion following the paradigm of learning from demonstration. The resulting p...
Article
Full-text available
Reliable physical interaction is essential for many important challenges in robotic manipulation. In this paper, we consider Constrained Object Manipulations tasks (COM), i.e. tasks for which constraints are imposed on the grasped object rather than on the robot’s configuration. To enable robust physical interaction with the environment, this paper...
Article
Full-text available
Rapid progress in the area of humanoid robots offers tremendous possibilities for investigating and improving social competences in people with social deficits, but remains yet unexplored in schizophrenia. In this study, we examined the influence of social feedbacks elicited by a humanoid robot on motor coordination during a human-robot interaction...
Poster
Over recent decades, myoelectric prostheses have demonstrated their potential to vastly improve autonomy and quality of life for upper-limb amputees by restoring some lost mobility. However, current upper-limb myoelectric prostheses are very limited in their number of controllable degrees of freedom, often allowing only a few discrete grasp types,...
Article
In this work, we tackle the problem of transform-invariant unsupervised learning in the space of Covariance matrices and applications thereof. We begin by introducing the Spectral Polytope Covariance Matrix (SPCM) Similarity function; a similarity function for Covariance matrices, invariant to any type of transformation. We then derive the SPCM-CRP...
Conference Paper
Full-text available
The problem of acquiring multiple tasks from demonstration is typically divided in two sequential processes: (1) the segmentation or identification of different subgoals/subtasks and (2) a separate learning process that parameter-izes a control policy for each subtask. As a result, segmentation criteria typically neglect the characteristics of cont...
Article
Full-text available
Simultaneous Localization and Mapping (SLAM) is concerned with the development of filters to accurately and efficiently infer the state parameters (position, orientation, etc.) of an agent and aspects of its environment, commonly referred to as the map. A mapping system is necessary for the agent to achieve situatedness, which is a precondition for...
Conference Paper
Full-text available
The use of coordinated multi-arm robotic systems allows to preform manipulations of heavy or bulky objects that would otherwise be infeasible for a single-arm robot. This paper concisely introduces our work on coordinated multi-arm control [Salehian et al., 2016a], where we proposed a virtual object based dynamical systems (DS) control law to gener...
Article
Full-text available
Mirror game test could detect schizophrenia A new test of movement and social interaction could detect markers of schizophrenia, and help to diagnose and manage the condition. In an effort to establish reliable indicators of schizophrenia, Piotr Slowinski at the University of Exeter, UK and colleagues developed a test that could detect deficits in...
Article
Predicting the grasping function during reach-to-grasp motions is essential for controlling a prosthetic hand or a robotic assistive device. An early accurate prediction increases the usability and the comfort of a prosthetic device. This work proposes an electromyographic-based learning approach that decodes the grasping intention at an early stag...
Conference Paper
Full-text available
Handovers are seamless events that occur frequently and naturally between people. Although previous works have focused on the design of robot handover controllers synthesizing one of the phases of a handover (approaching, passing, or retracting) in an isolated manner, we take a different approach and treat the handover as a single continuous entity...
Article
Compliance has become a key requirement for robots meant to interact with humans. It is viewed as a necessary property to increase safety and efficiency in human–robot cooperative actions. In humans, compliance takes three dimensions: mechanical, cognitive and social. While robotics has focused primarily on modeling the first two, we here discuss t...
Conference Paper
Full-text available
Among the symptoms of schizophrenia, deficits in the recognition of intention is one of the most studied. However, there is no cognitive model of intention recognition that takes into account both innate and environmental/developmental factors. This work proposes a developmental model of intention recognition based on a neural network. This model e...
Article
Impedance control is a commonly used control architecture for robotic manipulation. For increased flexibility, the impedance can be programmed to vary during the task. This has important implications on the stability properties of the control system, which are often overlooked in practice. In fact, the standard stability analysis is not valid in th...
Article
Full-text available
Haptic exploration has received a great deal of attention of late thanks to the variety of commercially available tactile sensors. While the majority of previous works consider control of a single contact point at a time, we tackle simultaneous control of multiple contact points on several links. In addition, we use information from the existing ta...
Article
We present a unified framework for grasp planning and in-hand grasp adaptation using visual, tactile, and proprioceptive feedback. The main objective of the proposed framework is to enable fingertip grasping by addressing problems of changed weight of the object, slippage, and external disturbances. For this purpose we introduce the Hierarchical Fi...
Article
Full-text available
Abstract: Background: The use of humanoid robots to play a therapeutic role in helping individuals with social disorders such as autism is a newly emerging field, but remains unexplored in schizophrenia. As the ability for robots to convey emotion appear of fundamental importance for human-robot interactions, we aimed to evaluate how schizophrenia...
Conference Paper
Full-text available
This paper contributes a novel framework that enables a robotic agent to efficiently learn and synthesize believable handwriting motion. We situate the framework as a foundation with the goal of allowing children to observe, correct and engage with the robot to learn themselves the handwriting skill. The framework adapts the principle behind ensemb...