Vincent Bonnet

University of Paul Sabatier, Toulouse · LAAS-CNRS

Modeling the interface between the lower limb segments and a socket, orthosis or exoskeleton is crucial to the design, control, and assessment of such devices. The present study aimed to estimate translational and rotational soft tissue stiffness at the thigh and shank during daily living activities performed by six subjects. Smooth orthogonal deco...

Multi-modal assistive system is a hybrid system that aims to provide assistance-as-needed for paretic subjects. The hybrid system combines human muscle efforts, stimulated by a Functional Electric Stimulator (FES) and an lower-limb active exoskeleton. With optimal sharing of the two activation inputs, a hybrid system could overcome several challeng...

Human gait patterns have been intensively studied, both from medical and engineering perspectives, to understand and compensate pathologies. However, the muscle-force sharing problem is still debated as acquiring individual muscle force measurements is challenging, requiring the use of invasive devices. Recent studies, using various objective funct...

As an important movement of the daily living activities, sit-to-stand (STS) movement is usually a difficult task facing elderly and dependent people. In this article, a novel impedance modulation strategy of a lower-limb exoskeleton is proposed to provide appropriate power and balance assistance during STS movements while preserving the wearer’s co...

This study investigates the possibility of estimating lower-limb joint kinematics and meaningful performance indexes for physiotherapists, during gait on a treadmill based on data collected from a sparse placement of new Visual Inertial Measurement Units (VIMU) and the use of an Extended Kalman Filter (EKF). The proposed EKF takes advantage of the...

Human–robot interaction requires a robust estimate of human motion in real time. This work presents a fusion algorithm for joint center positions tracking from multiple depth cameras to improve human motion analysis accuracy. The main contribution is the proposed algorithm based on body tracking measurement fusion with an extended Kalman filter and...

This study aims at developing and evaluating an affordable and user-friendly motion capture system for human upper limbs’ joint kinematics estimation. The objective is to provide quantitative assessments during the clinical evaluation of poststroke patients performing daily living activities. The proposed system is based on the simultaneous use of...

This work proposes to improve the accuracy of joint angle estimates obtained from an RGB-D sensor. It is based on a constrained extended Kalman Filter that tracks inputted measured joint centers. Since the proposed approach uses a biomechanical model, it allows physically consistent constrained joint angles and constant segment lengths to be obtain...

Assessment of gait parameters is commonly performed through the high-end motion tracking systems, which limits the measurement to sophisticated laboratory settings due to its excessive cost. Recently, Microsoft Kinect (v2) sensor has become popular in clinical gait analysis due to its low-cost. But, determining the accuracy of its RGB-D image data...

44th Congress of the Société de Biomécanique, Poitiers, France, 28/10/2019 - 30/10/2019

Accurate geometric and inertial parameter estimates of a modern manipulator are of crucial importance to obtain good performances during a contact task or for obtaining more and more required realistic simulations. CAD data are often provided by the manufacturer, but these are inaccurate and do not take into account eventual end-effector modificati...

In human motion science, the dynamics plays an important role. It relates the movement of the human to the forces necessary to achieve this movement. It also relates the human and its environment through interaction forces. Estimating subject-specific dynamic models is a challenging problem, due to the need for both accurate measurement and modelin...

The present study aims at designing and evaluating a low-cost, simple and portable system for human kinematics (joint angles) and kinetics (joint torques) motion assessment. The system is based on a single camera, a set of customized markers, low-cost inertial measurement units and an affordable Wii Balance board. The automatically detected and tra...

In realistic situations such as human-robot interactions or contact tasks, robots must have the capacity to adapt accordingly to their environment, other processes and systems. Adaptive model based controllers, that requires accurate dynamic and geometric robot’s information, can be used. Accurate estimations of the inertial and geometric parameter...

Knowledge of the inertial parameters of a humanoid robot is crucial for the development of model-based controllers or realistic simulation and motion planning in dynamic situations. Inertial parameters are usually provided from CAD data and thus are inaccurate especially if the robot is modified over time. Recent results showed that the inertial pa...

This paper presents a method allowing a simple and efficient sensitivity analysis of dynamics parameters of complex whole-body human model. The proposed method is based on the ground reaction and joint moment regressor matrices, developed initially in robotics system identification theory, and involved in the equations of motion of the human body....

To reduce the impact of the soft tissue artefact (STA) on the estimate of skeletal movement using stereophotogrammetric and skin-marker data, multi-body kinematics optimisation (MKO) and extended Kalman filters (EKF) have been proposed. This paper assessed the feasibility and efficiency of these methods when they embed a mathematical model of the S...

This study aims at developing and evaluating a new practical method for the real-time estimate of joint torques and external wrenches during multi-contact sit-to-stand task using kinematics data only. The proposed method allows also identifying subject specific body inertial segment parameters that are required to perform inverse dynamics. The iden...

This work proposes a method to enable the use of non-intrusive, small, wearable, wireless sensors to estimate the pose of the lower body during gait and other periodic motions and to extract objective performance measures useful for physiotherapy. The Rhythmic Extended Kalman Filter (Rhythmic- EKF) algorithm is developed to estimate the pose, learn...

This paper presents a method for real-time estimation of the kinematics and kinetics of a human body performing a sagittal symmetric motor task, which would minimize the impact of the stereophotogrammetric soft tissue artefacts (STA). The method is based on a bi-dimensional mechanical model of the locomotor apparatus the state variables of which (j...

This paper proposes a new control framework to restore the coordination between upper (functional) and lower (paralyzed) limbs in the context of functional electrical stimulation in completely paraplegic individuals. A kinematic decoupling between the lower and upper limbs controls the 3D whole-body center of mass location and the relative foot pos...

Knowledge of the mass and inertial parameters of a humanoid robot or a human being is crucial for the development of model-based control, as well as for monitoring the rehabilitation process. These parameters are also important for obtaining realistic simulations in the field of motion planning and human motor control. For robots, they are often pr...

This study aims to develop and evaluate a new method for the automatic extraction and estimate of back anatomical landmark positions and of 3D spine curve from Kinect sensor data. The proposed method allows to robustly reconstruct different indexes of back deformity used in the evaluation of scoliosis. The algorithm input data are the depth map and...

This paper presents a method for the real-time determination of joint angles, velocities, accelerations and joint torques of a human. The proposed method is based on a constrained Extended Kalman Filter that combines stereophotogrammetric and dynamometric data. In addition to the joint variables, subject-specific segment lengths and inertial parame...

In this study, we propose to explore inverse optimization process to better understand human arm motion in industrial screwing task. The process combines several criteria to minimize such as energy expenditure or trajectory smoothness leading to the optimal trajectory of a typical screwing task, often performed by workers. Estimated joint trajector...

This study aimed at developing and evaluating a new method for the fast and reliable identification of body segment inertial parameters with a planar model using affordable sensors. A Kinect sensor, with a new marker-based tracking system, and a Wii balance board were used as an affordable and portable motion capture system. A set of optimal exciti...

This paper proposes an affordable mobile platform for pathological gait analysis. Gait spatio-temporal parameters are of great importance in clinical evaluation but often require expensive equipment and are limited to a small and controlled environment. The proposed system uses state-of-the art robotic tools, in contrast to their original use, for...

Entropy measures are often used to quantify the regularity of postural sway time series. Recent methodological developments provided both multivariate and multiscale approaches allowing the extraction of complexity features from physiological signals; see “Dynamical complexity of human responses: A multivariate data-adaptive framework,” in Bulletin...

This paper investigated the possibility of estimating 3D lower limb joint kinematics during five popular rehabilitation exercises of the hip and knee joints based on the data collected from a single inertial measurement unit located on the shank. The leg was modeled as a four-degree-of-freedom serial chain, and the relevant joint angles were repres...

he trajectory of the whole body center of mass (CoM) is useful as a reliable metric of postural stability. If the evaluation of a subject-specific CoM were available outside of the laboratory environment, it would improve the assessment of the effects of physical rehabilitation. This paper develops a method that enables tracking CoM position using...

This study investigates the possibility of using the so-called Statically Equivalent Serial Chain approach to estimate the subject-specific 3D whole body centre of mass (CoM) location. This approach is based on a compact formulation of the 3D whole body CoM position associated with a least squares identification process. This process requires a cal...

The present study aims at designing and evaluating a low-cost, simple and portable system for arm joint angle estimation during grasping-like motions. The system is based on a single RGB-D camera and three customized markers. The automatically detected and tracked marker positions were used as inputs to an offline inverse kinematic process based on...

In this study, we propose to evaluate a 7 DOF exoskeleton in terms of motion control. Using criteria from the human motor control literature, inverse optimization was performed to assess an industrial screwing movement. The results of our study show that the hybrid composition of the free arm movement was accurately determined. At contrary, when we...

In PSA Peugeot Citroen factories, high precision requirements of workstations make them being manual. One of the main goal of the car manufacturer is to minimize the pain of workers while maintaining high efficiency of production lines. Consequently, assisting operators with an exoskeleton is a potential solution for improving ergonomics of painful...

The present study was aimed at evaluating the Empirical Mode Decomposition (EMD) method to estimate the 3D orientation of the lower trunk during walking using the angular velocity signals generated by a wearable inertial measurement unit (IMU) and notably flawed by drift. The IMU was mounted on the lower trunk (L4-L5) with its active axes aligned w...

This preliminary study aimed at analyzing the direction of exchanges between the hip and the ankle movement in a visual tracking task (Bonnet et al., 2011). The rate of the visual target's oscillation was scaled up from 0.1 to 0.65 Hz, Movements were essentially embedded in the sagittal plane. The angle of hip and ankle joints were estimated from m...

This preliminary study aimed at analyzing the direction of exchanges between the hip and the ankle movement in a visual tracking task (Bonnet et al., 2011). The rate of the visual target's oscillation was scaled up from 0.1 to 0.65 Hz, Movements were essentially embedded in the sagittal plane. The angle of hip and ankle joints were estimated from m...

Trunk mobility impairment can cause balance, postural and gait challenges during overground level walking in patients with different pathologies. Assessment of the rotations of the trunk during walking with an abnormal gait can provide knowledge required for a better understanding of the nature of the motor control deficit and support decision-maki...

Background The present study aimed at devising a data processing procedure that provides an optimal estimation of the 3-D instantaneous orientation of an inertial measurement unit (IMU). This result is usually obtained by fusing the data measured with accelerometers, gyroscopes, and magnetometers. Nevertheless, issues related to compensation of int...

This study aimed at the real-time estimation of the lower-limb joint and torso kinematics during a squat exercise, performed in the sagittal plane, using a single inertial measurement unit placed on the lower back. The human body was modeled with a three-degrees-of-freedom planar chain. The planar IMU orientation and vertical displacement were esti...

Our aim is to develop an algebraic approach to estimate human posture in the sagittal plane using Inertial Measurement Unit (IMU) providing accelerations and angular velocities. For this purpose, we address the issue of the estimation of the amplitude, frequency and phase of a biased and noisy sum of three sinusoidal waveform signals on a moving ti...

The objective of this paper is to present a new paradigm in control strategy for unsupported paraplegic standing, based on closed-loop control of paraplegics' lower extremities. The main advantage of our approach is taking into account voluntary motions of the upper-part of the body by controlling Center of Mass (CoM) position. The validity of our...

The objective of this paper is to present a new paradigm in control strategy for unsupported paraplegic standing, based on closed-loop control of paraplegics' lower extremities. The main advantage of our approach is taking into account voluntary motions of the upper-part of the body by controlling Center of Mass (CoM) position. The validity of our...

In this paper a human-based control strategy is proposed for walking of humanoid robots. Its basic idea lies in the control of the CoM as well as the relative position of robot's feet. Through the proposed study, it is shown that this reduced set of data allows to fully describe and reproduce a whole body human-like walking. In addition of reducing...

This study proposes the use of a combination of Weighted Fourier Linear Combiner and Fourier Linear Combiner algorithms to estimate lower trunk orientation angles during walking using the three angular velocity components measured by an inertial measurement unit. The proposed method enables the determination in real-time of the rotations around thr...

The objective of this paper is to investigate what would be the optimal strategy for voluntary trunk movement, which would minimize hip, knee and ankle torques demanding as well minimal upper limb participation during Functional Electrical Stimulation (FES)-assisted sit to stand motion in person suffering from Spinal cord injury. Our results sugges...

The use of dynamic optimization as a tool to estimate joint kinematics and kinetics, and ground reaction forces using data from a single inertial measurement unit (IMU) positioned on the lower trunk was investigated. The feasibility of this approach and its accuracy was explored for the analysis of a squat task, focusing on the ankle, knee and hip...

This paper proposes a closed-loop optimal control model predicting changes between in-phase and anti-phase postural coordination during standing and related supra-postural activities. The model allows the evaluation of the influence of body dynamics and balance constraints onto the adoption of postural coordination. This model minimizes the instant...

We investigated dynamic optimization as a tool to improve functional electrical stimulation (FES) assisted sit to stand transfers of paraplegic subjects. The objective would be to find optimal strategy for voluntary trunk movement, which would minimize hip, knee and ankle torques and demand minimal upper limb participation during the motion. Motion...

A closed-loop model with actuator dynamics and sensory feedback has been developed to capture the complex postural behaviors observed in a human head tracking task. In motor-control literature, spindle feedback gains are scaled by the central nervous system to adapt muscle stiffness depending on the postural task. We propose to identify spindle ref...

This paper models recent data in the field of postural coordination showing the existence of self-organized postural states, and transition between them, underlying suprapostural tracking movements. The proposed closed-loop controller captures the complex postural behaviors observed in humans and can be used to implement efficient and simple balanc...

This paper models recent data in the field of postural coordination showing the existence of self-organized postural states, and transition between them, underlying supra-postural tracking movements. The proposed closed-loop controller captures the complex postural behaviors observed in humans and can be used to implement efficient and simple balan...