Alexandre Girard — accepted AI-conference papers

2023

Modular Magnetorheological Actuator With High Torque Density and Transparency for the Collaborative Robot Industry

Catherine Véronneau, Jeff Denis, Pierre Lhommeau, Alexandre St-Jean, Alexandre Girard, Jean-Sébastien Plante +1

RA-L 2023

In the last decade, the development of simple and easy-to-use robotics has provided a significant step towards the democratization of collaborative robots, which can now work closely alongside humans. However, state-of-the-art cobots still provide safety at the cost of work-speed, which is purposely

Cited by 15 Source ↗Scholar ↗

2022

Multimodal Hydrostatic Actuators for Wearable Robots: A Preliminary Assessment of Mass-Saving and Energy-Efficiency Opportunities

Jeff Denis, Alex Lecavalier, Jean-Sébastien Plante, Alexandre Girard

ICRA 2022poster

Wearable robots are limited by their actuators performances because they must bear the weight of their own power system and energy source. This paper explores the idea of leveraging hybrid modes to meet multiple operating points with a lightweight and efficient system by using hydraulic valves to dy…

Cited by 8 Source ↗Scholar ↗

2021

Low-Level Force-Control of MR-Hydrostatic Actuators

Jeff Denis, Jean-Sébastien Plante, Alexandre Girard

RA-L 2021

Precise and high-fidelity force control is critical for new generations of robots that interact with humans and unknown environments. Mobile robots, such as wearable devices and legged robots, must also be lightweight to accomplish their function. Hydrostatic transmissions have been proposed as a pr

Cited by 8 Source ↗Scholar ↗

2020

A Supernumerary Robotic Leg Powered by Magnetorheological Actuators to Assist Human Locomotion

Charles Khazoom, Pierre Caillouette, Alexandre Girard, Jean-Sébastien Plante

RA-L 2020

Supernumerary robotic limbs are emerging to augment human function. Unlike exoskeletons, these robots provide additional kinematic structures to the user that enable novel human-robot interactions. To assist walking, a supernumerary leg should be compliant to impacts, minimize efforts on users, move

Cited by 56 Source ↗Scholar ↗

2020

Multifunctional Remotely Actuated 3-DOF Supernumerary Robotic Arm Based on Magnetorheological Clutches and Hydrostatic Transmission Lines

Catherine Véronneau, Jeff Denis, Louis-Philippe Lebel, Marc Denninger, Vincent Blanchard, Alexandre Girard +1

RA-L 2020

Supernumerary robotic limbs (SRL) are wearable extra limbs intended to help humans perform physical tasks beyond conventional capabilities in domestic and industrial applications. However, unique design challenges are associated with SRLs as they are mounted on the human body. SRLs must!) be lightwe

Cited by 74 Source ↗Scholar ↗

2019

A Lightweight Force-Controllable Wearable Arm Based on Magnetorheological-Hydrostatic Actuators

Catherine Véronneau, Jeff Denis, Louis-Philippe Lebel, Marc Denninger, Jean-Sébastien Plante, Alexandre Girard

ICRA 2019poster

Supernumerary Robotic Limbs (SRLs) are wearable robots augmenting human capabilities by acting as a co-worker, reaching objects, support human arms, etc. However, existing SRLs lack the mechanical backdrivability and bandwidth required for tasks where the interaction forces must be controlled such a…

Cited by 35 Source ↗Scholar ↗

2019

Design and Control of a Multifunctional Ankle Exoskeleton Powered by Magnetorheological Actuators to Assist Walking, Jumping, and Landing

Charles Khazoom, Catherine Véronneau, Jean-Philippe Lucking Bigué, Jordane G. Grenier, Alexandre Girard, Jean-Sébastien Plante

RA-L 2019

Lower-limb exoskeletons have shown increasing potential to augment human performance in many locomotion tasks. However, most lower-limb exoskeletons use highly geared, nonback-drivable actuators with limited power and force bandwidth in order to be light enough to be carried without metabolic penalt

Cited by 69 Source ↗Scholar ↗

2017

Leveraging Natural Load Dynamics With Variable Gear-Ratio Actuators

Alexandre Girard, H. Harry Asada

RA-L 2017

This paper presents a robotic system where the gear-ratio of an actuator is dynamically changed to either leverage or attenuate the natural load dynamics. Based on this principle, lightweight robotic systems can be made fast and strong; exploiting the natural load dynamics for moving at higher speed

Cited by 18 Source ↗Scholar ↗

2016

A practical optimal control approach for two-speed actuators

Alexandre Girard, H. Harry Asada

ICRA 2016

This paper addresses the closed-loop control of an actuator with both a continuous input variable (motor torque) and a discrete input variable (mode selection). In many applications, robots have to bear large loads while moving slowly and also have to move quickly through the air with almost no load

Cited by 9 Source ↗Scholar ↗

2015

A two-speed actuator for robotics with fast seamless gear shifting

Alexandre Girard, H. Harry Asada

IROS 2015poster

In many applications, robots have to bear large loads while moving slowly and also have to move quickly through the air with almost no load. This leads to conflicting requirements for their actuators. Multiple gear ratios, like in a powertrain, address this issue by allowing an effective use of powe…

Cited by 38 Source ↗Scholar ↗