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Renaud Ronsse
Professor
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Recent publications

has always been intrigued by the neural control of human movements, and the way these principles can be transferred to human-centered robotics. Consequently, he is mainly active in the field of bio-inspired robotics, i.e. the design and control of robots obeying principles that are directly inspired by nature. This holds both regarding design issues, i.e. in the mechanical structure and actuation principles of the robot’s body; and control issues, i.e. in the algorithmic laws governing the robot behavior. His main application fields are medical robotics and humanoid robotics. In the former, he is active in the design and control of assistive and rehabilitation robots, mainly for the lower-limb. Bio-inspiration consists for instance in embedding elastic elements within the robot mechanical structure, thus reproducing muscle-like compliance. At the control level, he develops rehab robots whose behavior is governed by virtual spinal neural circuitries. This is well exemplified by the EU collaborative projects CYBERLEGs and CYBERLEGs++. Regarding humanoid robotics, he is again mainly involved in bio-inspired locomotion. His research driver is to design humanoid robot achieving better locomotion skills because they emulate human behavior. This is well exemplified by the EU collaborative project WALK-MAN. More recently, Renaud Ronsse developed an interest for the biomechanics of animals exchanging forces with the fluid they evolve in. He started a new collaborative research agenda to unveil the efficiency optimization mechanisms deployed by biological swimmers and flyers. Again, compliance and neural-like control structures are thought to play a significant role in this line of research.

IMMC main research direction(s):
Biomedical engineering
Dynamical and electromechanical systems

Keywords:
biomechanics
multi-body systems
robotics

Research group(s): MEED

PhD and Post-doc researchers under my supervision:

ELSA, an ankle-foot prosthesis to restore amputees locomotion
François Heremans

Over the last decade, active lower-limb prostheses demonstrated their ability to restore a physiological gait for lower-limb amputees by supplying the required positive energy balance during daily life locomotion activities.
However, the added-value of such devices is significantly impacted by their limited energetic autonomy, excessive weight and cost preventing their full appropriation by the users. There is thus a strong incentive to produce active yet affordable, lightweight and energy efficient devices.
To address these issues, we are developing the ELSA (Efficient Lockable Spring Ankle) prosthesis embedding both a lockable parallel spring and a series elastic actuator, tailored to the walking dynamics of a sound ankle. The first contribution concerns the developement of a bio-inspired, lightweight and stiffness adjustable parallel spring, comprising an energy efficient ratchet and pawl mechanism with servo actuation. The second contribution is the addition of a complementary rope-driven series elastic actuator to generate the active push-off.
Our new system produces a sound ankle torque pattern during flat ground walking. Up to 50% of the peak torque is generated passively at a negligible energetic cost (0.1 J/stride). By design, the total system is lightweight (1.2 kg) and low cost.

Modelisation and optimization of bird flight
Victor Colognesi

This research project aims at modeling and optimizing bird flight. The goal of this modelization is to get a deep understanding of the mechanisms that govern avian flight and the best way to understand it is to re-create it. That is, the flight will be modeled starting from the given anatomy of a bird and the kinematics will be the result of an optimization process aiming at the most optimal flight.
Compared to other existing studies on the subject of bird flight, this project will follow a "bottom-up" approach, all the way from muscle activation, up to the wing aerodynamics and gait optimization. This approach is necessary to be able to evaluate key values such as metabolic rates, ...
This will allow us to answer a few questions such as :
- What are the mechanisms enabling high efficiency in bird flight ?
- How do we achieve a stable flapping flight ?
This work is purely numerical. The bio-mechanical model of the bird is developed using the multi-body solver Robotran developed at UCLouvain. This bio-mechanical model will be coupled to an aerodynamical model based on a vortex particle-mesh code (VPM) developed at UCLouvain as well.

Flight Control and Wake Characterization of Migratory Birds
Gianmarco Ducci

The RevealFlight project aims at shedding light on the efficiency optimization mechanisms deployed by biological flyers, with a specific focus on migratory birds. The efficiency-seeking mechanisms will be sought through the numerical reproduction of flight that includes the morphology, the neuro-muscular configuration and the gait generation. This resulting gait then exploits aerodynamics at the scale of an individual (unsteady lift generation) and at the level of the flock (formation flight). This project thus proposes to synthesize the flight mechanics of birds into a unified framework, combining bio-mechanical, sensory, aerodynamic and social interaction models, in order to reproduce the flying gaits and the interactions within a flock.
A neuro-mechanical model of the birds is currently under development, capturing bio-inspired principles both in the wing bio-mechanics (e.g. structure and compliance) and in its coordinated control (through e.g. a network of coordinated oscillators). The dynamics of this model will be solved by means a multi-body solver and in turn, coupled to a massively parallel flow solver (an implementation of the Vortex Particle-Mesh method) in order to capture the bird’s wake up to the scales of the flock. The study of self-organization phenomena and inter-bird interactions are currently beginning on simple conceptual models, and will be gradually extended to more advanced models developed during the project. It will aim at comparing the efficiency of flocks of selfish flyers with that of flocks in which collaboration takes place, whether implicitly or explicitly.
In my global project picture, the following bottom-up strategy will be adopted:
- Wake characterization: This task studies the wake in terms of the vortex dynamics at play over long distances. The candidate will perform simulations of flying agents in long computational domains in order to capture the wake behavior (topology, instabilities and decay) over longer times and larger scales. This will provide another basis of validation of the project results, given the volume of work on bird wakes;
- Flight stabilization in turbulent or wake-impacted flow: This task aims at the realization of a stabilized flight within a perturbed flow. Two perturbations are envisioned: ambient turbulence and an analytical wake composed of two counter-rotating vortices. Il will Combine previously synthesized gaits and control schemes in order to study the stability of the flyer in a turbulent flow or inside a wake;
- Maneuvers: This task realizes the first maneuvers of the virtual flyer: avoidance and trajectory tracking that will be leveraged in the simulation of multiple flyers that need to interact and swap places. In the present task, this trajectory is still prescribed, in a step towards an autonomous decision-making agent. In order to realize maneuvers, this task implements a control layer above the controllers developed in earlier tasks. Complex maneuvers will be achieved by closing the loop between trajectory errors and the inputs of the lower level controller.

Locomotion assistance through active motor primitives
Henri Laloyaux

This project is about the development and validation of a new method for assisting human locomotion with robotic devices. It will be based on so-called “motor primitives”, i.e. fundamental units of action which have been identified in the human locomotor apparatus. These primitives will be constrained to be mathematical functions with a limited number of open parameters, therefore optimizing the computational efficiency. Next, the assistance will be designed to be adaptive to the user’s particular gait and status. Finally, some primitives will be specifically developed to support the user’s balance, on top of delivering energy for assisting locomotion. These three objectives will require first theoretical developments, and then experimental validation.

Captive Trajectory System for the handling of wake-impacted flow devices
Emile Moreau

The main objective of the thesis is to develop a Captive Trajectory System (CTS) for the handling of wake-impacted flow devices that are free flying or swimming, such as aircrafts or bio-inspired robots. Which means that there is no other external force applied on those models, barring gravity, than the one applied by the fluid.
The envisioned facility will be unique at an international level. At the same time, its scope of applications will be quite wide, covering, but not limited to, applied and fundamental fluid mechanics (fluid-structure interaction problems), biomechanics (biolocomotion), and civil engineering (wind or flow-structure interactions). Additionally, we see this project as a first foray into the emerging field of experimental studies augmented by Artificial Intelligence or co-simulation.
Nowadays, this is not experimentally achievable by the use of Lab facilities, because they only allow, at most, horizontal and vertical displacements and do not feature any force or motion control. Hence, the goal of this thesis, of a rather experimental nature, is to design a robotic system – possibly partially immersed – whose precision, sensing and control capabilities will be able to handle free-moving devices, and to validate fluid-structure interaction models developed by various IMMC research teams, also involved in the project.

Detecting and using locomotion affordances for lower-limb prostheses by active vision
Ali Hussein Al-Dabbagh

Healthy lower-limb biomechanics reveals that active prostheses are necessary to provide amputees with human-like dynamics in various locomotion tasks like walking or stair ascending/descending. Ali’s project is about the specific challenges associated to the transition between two of these tasks, where the control parameters of the device has to be smoothly and timely adapted. Active vision is proposed to be used to augment the prosthesis with vision-based detection of possible locomotion affordances, therefore anticipating these transitions as a function of the user’s behavior.

PaDAWAn: Parkinson's Disease - Adaptive Walking Assistance
Virginie Otlet

Characterization of validation of ELSA prosthesis.
Jeanne Evrard

Design, Control and Validation of an Active Bionic Leg for Patients with Hip Disarticulation
Louis Devillez

Hip disarticulation is a highly mutilating intervention, which consists in amputating a whole leg to circumvent the propagation of a bone tumor in the pelvis. Although bionic prostheses for transtibial and transfemoral amputees are rapidly developing nowadays, active hip modules are not part of this research agenda yet. This is likely due to the relatively low incidence of hip disarticulation, and to the intrinsic challenges associated to the interfacing between an amputated subject and a whole artificial leg. In this project, I propose to address three research questions, related to the design, control, and validation of an active leg prosthesis for a disarticulated amputee. First, I will design an innovative active hip prosthesis. Combined with existing knee and ankle modules, this will provide the first full-leg prosthesis having the capacity to continuously deliver mechanical energy through each of its three joints. Secondly, I will design a control strategy to achieve levelground walking by interfacing this device with a disarticulated amputee. This control framework will rely on bioinspired control mechanisms through a neuro-mechanical model of the lower limb, combining reflexes and a descending oscillator. A particular challenges will consist in designing a “steering” (or “pacing”) signal from the detected motion intention of the user, in order to guide the behavior of the prosthesis in symbiosis with the intact segments. A second version of the controller will be designed with specific focus on enhancing the user’s balance. Last but not least, the project will also comprise a strong experimental section, in order to validate the proposed ideas with disarticulated amputees wearing our prototype.

BleDePro: Blended Design of Bionic Prosthesis over a Continuous Space
Julien Guiaux Brinon

The ambition of this project is to provide a framework having the potential to drastically change the way bionic prostheses are designed nowadays, in particular for the lower-limb. Bionic prostheses aim at replacing the missing leg joints and segments of amputees. Their design specifications are challenged by the movement biomechanics that should be assisted (highly fluctuating torque and power profiles) and strong constraints regarding their usability (weight, volume, noise, comfort). Therefore, researchers investigated the design of their actuators by combining passive elastic elements to store and release energy, and active systems to provide net energy. However, these devices systematically integrate of-the-shelf components, such as motors, sensors, transmissions, and springs. Consequently, this constraints the design optimization to “discrete” variables only – i.e. the different configurations provided by the suppliers – and also narrows the possibility of integrating several functions into more compact systems displaying better performance. In this project, we will break this ceiling, by developing, implementing, testing, and validating an integrated method for designing so-called “esensorimotor systems” for bionic prostheses. Instead of restricting ourselves to the integration of of-the-shelf components, we will envisage the design in a holistic way and seek for the

highest possible level of integration of functions, over a continuous design space. A second contribution of the present project is to extend the set of tasks that could be assisted by lower-limb bionic prostheses. On top of bipedal locomotion tasks, our design will also cover the assistance of cycling, therefore raising the potential for amputees to contribute to sustainable and healthy mobility. The different requirements of these tasks will be integrated into our design by optimizing its specifications to reach the most versatile possible system. Our approach will be embodied into the design of a specific joint, i.e. the knee. It is characterized by conflicting requirements regarding velocity and torque profiles, as a function of the task being executed.

Recent publications

See complete list of publications

Journal Articles

1. Al-Dabbagh, Ali; Ronsse, Renaud. Depth Vision based Terrain Detection Algorithm during Human Locomotion. In: IEEE Transactions on Medical Robotics and Bionics, Vol. 4, no. 4, p. 1010-1021 (2022). doi:10.1109/tmrb.2022.3206602. http://hdl.handle.net/2078.1/265373

2. Chatelain, Philippe; Vitucci, Gennaro; Ronsse, Renaud; Colognesi, Victor; Ducci, Gianmarco. Stability and Sensitivity Analysis of Bird Flapping Flight. In: Journal of Nonlinear Science, Vol. 31, no.2, p. 47 (2021). doi:10.1007/s00332-021-09698-1. http://hdl.handle.net/2078.1/244939

3. Chatelain, Philippe; Colognesi, Victor; Ronsse, Renaud. A model coupling biomechanics and fluid dynamics for the simulation of controlled flapping flight. In: Bioinspiration & Biomimetics, Vol. 16, no.2, p. 026023 (2021). doi:10.1088/1748-3190/abdd9c. http://hdl.handle.net/2078.1/241981

4. Tolu, Silvia; Heins, Sophie; Ronsse, Renaud. Online Learning of the Dynamical Internal Model of Transfemoral Prosthesis for Enhancing Compliance. In: IEEE Robotics and Automation Letters, Vol. 6, no. 4, p. 6156-6163 (2021). doi:10.1109/LRA.2021.3091953. http://hdl.handle.net/2078.1/248933

5. Ronsse, Renaud; Al-Dabbagh, Ali Hussein. A review of terrain detection systems for applications in locomotion assistance. In: Robotics and Autonomous Systems, Vol. 133, p. 103628 (2020). doi:10.1016/j.robot.2020.103628. http://hdl.handle.net/2078.1/232844

6. Van der Noot, Nicolas; Ronsse, Renaud; Ijspeert, Auke Jan. Neuromuscular model achieving speed control and steering with a 3D bipedal walker. In: Autonomous Robots, Vol. 43, p. 1537-1554 (2019). doi:10.1007/s10514-018-9814-6. http://hdl.handle.net/2078.1/204150

7. Stoquart, Gaëtan; Leconte, Patricia; Lejeune, Thierry; Ronsse, Renaud. Rhythmic robotic training enhances motor skills of both rhythmic and discrete upper-limb movements after stroke : a longitudinal pilot study. In: International Journal of Rehabilitation Research, Vol. 42(1):46-55., no. 1, p. 46-55 (2019). doi:10.1097/mrr.0000000000000325. http://hdl.handle.net/2078.1/204563

8. Gazzola, Mattia; Chatelain, Philippe; Ronsse, Renaud; Bernier, Caroline. Simulations of propelling and energy harvesting articulated bodies via vortex particle-mesh methods. In: Journal of Computational Physics, Vol. 392, p. 34-55 (1 september 2019). doi:10.1016/j.jcp.2019.04.036. http://hdl.handle.net/2078.1/214744

9. Van der Noot, Nicolas; Ronsse, Renaud; Ijspeert, Auke Jan. Bio-inspired controller achieving forward speed modulation with a 3D bipedal walker. In: The International Journal of Robotics Research, Vol. 37, p. 168-196 (2018). doi:10.1177/0278364917743320. http://hdl.handle.net/2078.1/194213

10. Lefeber, Dirk; Flynn, Louis; Ronsse, Renaud; Heins, Sophie; Geeroms, Joost. Torque control of an active elastic transfemoral prosthesis via quasi-static modelling. In: Robotics and Autonomous Systems, Vol. 107, p. 100-115 (2018). doi:10.1016/j.robot.2018.05.015. http://hdl.handle.net/2078.1/199538

Patents

1. Dehez, Bruno; Heremans, François; Ronsse, Renaud. Prosthesis or Orthosis. http://hdl.handle.net/2078.1/263251 http://hdl.handle.net/2078.1/263251

2. Dehez, Bruno; Everarts, Christophe; Ronsse, Renaud. Continuously Variable Planetary Transmission. http://hdl.handle.net/2078.1/169001 http://hdl.handle.net/2078.1/169001

Conference Papers

1. Ronsse, Renaud; Heins, Sophie. Compliant Control of a Transfemoral Prosthesis Combining Predictive Learning and Primitive-Based Reference Trajectories. In: Biosystems & Biorobotics, 2022, 978-3-030-69546-0, p. 89-93 xxx. doi:10.1007/978-3-030-69547-7_15. http://hdl.handle.net/2078.1/248930

2. Ronsse, Renaud; Al-Dabbagh, Ali Hussein. A New Terrain Recognition Approach for Predictive Control of Assistive Devices Using Depth Vision. In: Biosystems & Biorobotics, Moreno J.C. Masood J. Schneider U. Maufroy C. Pons J.L. 2022, 978-3-030-69546-0, p. 443-447 xxx. doi:10.1007/978-3-030-69547-7_71. http://hdl.handle.net/2078.1/248928

3. Ronsse, Renaud; Otlet, Virginie. Predicting the effects of oscillator-based assistance on stride-to-stride variability of Parkinsonian walkers. In: 2022 International Conference on Robotics and Automation (ICRA). Vol. X, no.X, p. 8083-8089 (2022). I E E E Computer Society, 2022 xxx. doi:10.1109/icra46639.2022.9811822. http://hdl.handle.net/2078.1/263930

4. Laloyaux, Henri; Ronsse, Renaud. Reconstruction of Hip Moments Through Constrained Shape Primitives. In: Biosystems & Biorobotics, 2022, 978-3-030-69546-0, p. 383-388 xxx. doi:10.1007/978-3-030-69547-7_62. http://hdl.handle.net/2078.1/248929

5. Livolsi, Chiara; Laloyaux, Henri; Ronsse, Renaud; Vitiello, Nicola; Pergolini, Andrea; Crea, Simona; Beatriz Sanz-Morère, Clara. Experimental Assessment of a Control Strategy for Locomotion Assistance Relying on Simplified Motor Primitives. 2022 xxx. http://hdl.handle.net/2078.1/266714

6. Al-Dabbagh, Ali; Ronsse, Renaud. Using Depth Vision for Real-Time Terrain Detection in Various Locomotion Modes. 2021 xxx. http://hdl.handle.net/2078.1/263252

7. Al-Dabbagh, Ali; Ronsse, Renaud. Using Depth Vision for Terrain Detection during Active Locomotion*. In: 2021 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2021, 978-1-6654-1714-3, p. 208--515 xxx. doi:10.1109/iros51168.2021.9636077. http://hdl.handle.net/2078.1/255303

8. Van der Noot, Nicolas; Ronsse, Renaud; Ijspeert, Auke Jan. Trajectory Planning of a Bio-inspired Walker in 3D Cluttered Environments using Internal Models. In: 2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob), IEEE, 2020, 9781728159072 xxx. doi:10.1109/biorob49111.2020.9224461. http://hdl.handle.net/2078.1/238574

9. Heins, Sophie; Flynn, Louis; Laloyaux, Henri; Ronsse, Renaud; Lefeber, Dirk; Geeroms, Joost. Compliant Control of a Transfemoral Prosthesis by combining Feed-Forward and Feedback. In: 2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob), IEEE, 2020, 9781728159072 xxx. doi:10.1109/biorob49111.2020.9224434. http://hdl.handle.net/2078.1/238572

10. Vijayakumar, Sethu; Heremans, François; Bouri, Mohamed; Dehez, Bruno; Ronsse, Renaud. Bio-inspired design and validation of the Efficient Lockable Spring Ankle (ELSA) prosthesis. In: 2019 IEEE 16th International Conference on Rehabilitation Robotics (ICORR), IEEE, 2019, 9781728127552 xxx. doi:10.1109/icorr.2019.8779421. http://hdl.handle.net/2078.1/221894

Book Chapters

1. Ronsse, Renaud. Adaptive Oscillators as Template for Modeling and Assisting Rhythmic Movements. In: Biosystems and Biorobotics , Springer International Publishing, 2022, p. 271-275. 978-3-030-70316-5. xxx xxx. doi:10.1007/978-3-030-70316-5_44. http://hdl.handle.net/2078.1/252386

2. Ronsse, Renaud. Bio-inspired Walking: From Humanoids to Assistive Devices. In: Biosystems & Biorobotics : Wearable Robotics: Challenges and Trends (Wearable Robotics: Challenges and Trends; xxx), Springer: Cham, 2019, p. 271-275. 9783030018863. xxx xxx. doi:10.1007/978-3-030-01887-0_52. http://hdl.handle.net/2078.1/204504

3. Ronsse, Renaud; Lefèvre, Philippe. Bio-Inspired Robotics: From Rehabilitation to Human Augmentation. In: The Genesis of Concepts and the Confrontation of Rationalities (Bibliotheca Ephemeridum Theologicarum Lovaniensium; xxx), Peeters: Louvain, 2018, p. 245. 978-90-429-3597-6. xxx xxx. http://hdl.handle.net/2078.1/197601

4. Tsagarakis, Nikolaos; Fisette, Paul; Ronsse, Renaud; Dallali, Houman; Natale, Lorenzo; Cardellino, Alberto; Habra, Timothée. Robotran-YARP interface: a framework for real-time controller developments based on multibody dynamics simulations. In: Multibody Dynamics Computational Methods and Applications , Springer International Publishing, 2016. 978-3-319-30612-4. xxx xxx. doi:10.1007/978-3-319-30614-8. http://hdl.handle.net/2078.1/173786