Publications de Mahdi Khoramshahi

Force Adaptation in Contact Tasks with Dynamical Systems

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

In many tasks such as finishing operations, achieving accurate force tracking is essential. However, uncertainties in the robot dynamics and the environment limit the force tracking accuracy. Learning a compensation model for these uncertainties to reduce ...

IEEE2020

Arm-hand motion-force coordination for physical interactions with non-flat surfaces using dynamical systems: Toward compliant robotic massage

Aude Billard, Mahdi Khoramshahi, Seyed Sina Mirrazavi Salehian, Aileen Charlotte Naef, Karl Gustav Henriks

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. Al ...

IEEE2020

A dynamical system approach for detection and reaction to human guidance in physical human-robot interaction

Aude Billard, Mahdi Khoramshahi

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 in ...

SPRINGER2020

A Dynamical System Approach to Task-Adaptation in Physical Human-Robot Interaction

Aude Billard, Mahdi Khoramshahi

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 all ...

2019

A Dynamical System Approach to Motion and Force Generation in Contact Tasks

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

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 co ...

MIT PRESS2019

Evaluation of an Industrial Robotic Assistant in an Ecological Environment

Aude Billard, Mahdi Khoramshahi, Leonardo Urbano, Baptiste Busch

Social robotic assistants have been widely studied and deployed as telepresence tools or caregivers. Evaluating their design and impact on the people interacting with them is of prime importance. In this research, we evaluate the usability and impact of AR ...

2019

A Dynamical System Approach to Motion and Force Generation in Contact Tasks

Aude Billard, Walid Amanhoud, Mahdi Khoramshahi

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 co ...

Robotics: Science and Systems (RSS)2019

From human-intention recognition to compliant control using dynamical systems in physical human-robot interaction

Mahdi Khoramshahi

Human ability to coordinate one's actions with other individuals to perform a task together is fascinating. For example, we coordinate our action with others when we carry a heavy object or when we construct a piece of furniture. Capabilities such as (1) f ...

EPFL2019

Does this robot have a mind? Schizophrenia patients' mind perception toward humanoid robots

Aude Billard, Mahdi Khoramshahi, Laura Bénédicte Marine Cohen

2018

From Human Physical Interaction To Online Motion Adaptation Using Parameterized Dynamical Systems

Aude Billard, Mahdi Khoramshahi, Thomas Triquet

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 mod ...

2018

Influence of Facial Feedback and Mind Perception During a Cooperative Human-Robot Task in Schizophrenia

Aude Billard, Mahdi Khoramshahi, Laura Bénédicte Marine Cohen

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 ...

Nature Research2017

Unravelling socio-motor biomarkers in schizophrenia

Aude Billard, Mahdi Khoramshahi, Laura Bénédicte Marine Cohen

We present novel, low-cost and non-invasive potential diagnostic biomarkers of schizophrenia. They are based on the 'mirrorgame', a coordination task in which two partners are asked to mimic each other's hand movements. In particular, we use the patient's ...

2017

Role of Gaze Cues in Interpersonal Motor Coordination: Towards Higher Affiliation in Human-Robot Interaction

Aude Billard, Ashwini Shukla, Mahdi Khoramshahi

Background The ability to follow one another's gaze plays an important role in our social cognition; especially when we synchronously perform tasks together. We investigate how gaze cues can improve performance in a simple coordination task (i.e., the mirr ...

Public Library of Science2016

From joint-attention to joint-action: Effects of gaze on human following motion

Aude Billard, Ashwini Shukla, Mahdi Khoramshahi

2015

Cognitive mechanism in synchronized motion: An internal predictive model for manual tracking control

Aude Billard, Ashwini Shukla, Mahdi Khoramshahi

Many daily tasks involve spatio-temporal coordination between two agents. Study of such coordinated actions in human-human and human-robot interaction has received increased attention of late. In this work, we use the mirror paradigm to study coupling of h ...

2014

Piecewise linear spine for speed-energy efficiency trade-off in quadruped robots

Auke Ijspeert, Mahdi Khoramshahi

We compare the effects of linear and piecewise linear compliant spines on locomotion performance of quadruped robots in terms of energy efficiency and locomotion speed through a set of simulations and experiments. We first present a simple locomotion syste ...

Elsevier2013

Benefits of an Active Spine Supported Bounding Locomotion With a Small Compliant Quadruped Robot

Auke Ijspeert, Alexander Spröwitz, Alexandre Tuleu, Mahdi Khoramshahi

We studied the effect of the control of an active spine versus a fixed spine, on a quadruped robot run- ning in bound gait. Active spine supported actuation led to faster locomotion, with less foot sliding on the ground, and a higher stability to go straig ...

2013

Angular Motion Control Using a Closed-Loop CPG for a Water-Running Robot

Auke Ijspeert, Mahdi Khoramshahi, Metin Sitti

The Basilisk Lizard’s striking ability to sustain highly dynamic legged locomotion on a range of surfaces from hard-ground to water is a remarkable feat [1]. Most legged robots would have difficulty emulating this animal’s ability to robustly locomote on y ...

Carnegie Mellon University2013

Use Your Spine! Effect of Active Spine Movements on Horizontal Impulse and Cost of Transport in a Bounding, Quadruped Robot

Auke Ijspeert, Alexander Spröwitz, Alexandre Tuleu, Mahdi Khoramshahi

2013