Pneumatic Artificial Muscles (PAMs) are complex nonlinear systems characterized by hysteresis, making them challenging to model with classical system identification methods. While deep learning has emerged as a powerful tool for modeling nonlinear systems from data, purely neural networkbased models often lack interpretability and are prone to overfitting. To address these challenges, this study explores several hybrid approaches that combine analytical models with neural networks to model PAM behavior more effectively. The results demonstrate that hybrid models significantly outperform both purely analytical and black-box neural network models, particularly in terms of generalization and dynamic accuracy. Among the approaches, the Physics-Informed Neural Network (PINN) unsupervised model shows the most robust performance, capturing complex PAM dynamics while maintaining computational efficiency. These findings suggest that hybrid modeling is a promising and scalable solution for accurately representing the intricate behavior of PAMs.

Automatic tracking of viral and intracellular structures displayed as spots with varying sizes in fluorescence microscopy images is an important task to quantify cellular processes. We propose a novel probabilistic tracking approach for multiple particle tracking based on multi-detector and multi-scale data fusion as well as Bayesian smoothing. The approach integrates results from multiple detectors using a novel intensity-based covariance intersection method which takes into account information about the image intensities, positions, and uncertainties. The method ensures a consistent estimate of multiple fused particle detections and does not require an optimization step. Our probabilistic tracking approach performs data fusion of detections from classical and deep learning methods as well as exploits single-scale and multi-scale detections. In addition, we use Bayesian smoothing to fuse information of predictions from both past and future time points. We evaluated our approach using image data of the Particle Tracking Challenge and achieved state-of-the-art results or outperformed previous methods. Our method was also assessed on challenging live cell fluorescence microscopy image data of viral and cellular proteins expressed in hepatitis C virus-infected cells and chromatin structures in non-infected cells, acquired at different spatial-temporal resolutions. We found that the proposed approach outperforms existing methods.

Haptic simulators are used in many education domains to improve hands-on training performance. Many of these simulators are used in the medical domain, where it is particularly important to be trained, guided by an expert. However, the majority of haptic hands-on training devices are usable by only one user at the same time, either the trainer or the trainee. Dual-user approaches have enhanced this situation by allowing both trainer and trainee to use the same simulator to introduce guided training into the simulation. In this paper, we introduce a multi-trainee architecture that expands further a former dual-user hands-on haptic training solution designed according to an energetic approach. This system will permit several trainees to be involved in the same simulation at the same time, guided by a single trainer. It paves the way to the multi-trainee hands-on training on haptic simulators.

This paper proposes a general approach to design a feedback control law for DC/DC power converters. These last ones can be modeled as switched port-Hamiltonian systems. Based on Lyapunov theory, a candidate Lyapunov function representing the energy of the system is proposed. Advantages of the resulting control law include ease of design and implementation in real time applications. The proposed control is applied in simulation for Buck, Buck-Boost, SEPIC and Ćuk converters. A comparison with a PWM state feedback control law is given for the last two converters.

A hybrid Lyapunov control for a flying capacitor multicellular converter is presented. This control law is based on the Port-Hamiltonian (PH) formalism of power converters and allows to enhance load current quality and reduce switching losses. The proposed control is applied to a three-cell multicellular converter. A procedure for selecting the best weighting parameters in the control law according to a performance criterion is presented. The simulation and experimental results indicate the stability of the control for changes in the reference signals. A comparison with a different Lyapunov control technique shows the performance of the proposed solution and the advantage of such a strategy in order to reduce the switching losses.

This paper presents a Bond Graph (BG) modellingapproach to add and exploit on existing Modelica mod-els some information on the energy structure of thesystems. The developed models in the ThermosysProlibrary (Modelica-based) are already validated againstthe experimental data in previous works. A plate heatexchanger (PHE), which is equipment for nuclear powerplants, is considered as a case study in this paper.Simulation results of the BG model for the counterflowPHE are compared with simulation results of the testedModelica model. Comparisons show good agreementbetween both model results.

This paper deals with a comparative analysis of different pick & place strategies. The purpose is to give some rules to obtain a good sizing in terms of components (number of robots, conveyor speed) and control laws (individual scheduling rules of each robot, collaborative strategy of all the robots) of a multi-robot cell. This approach is validated by the use of a new simulation tool combining a behavioral simulation of multiple robots and the product flows. This simulation tool takes into account not only the end effector, but also the robots collaborative aspect to ensure the desired overall performance for a given task.

A pneumatic actuator with solenoid valves is a discontinuous-input system because each valve can be either in on or off state. For such an actuator, this paper proposes a sliding-mode control scheme based on an averaged continuous-input equivalent model for the open-loop system. The averaged model is obtained from the nonlinear dynamics of the open-loop discontinuous-input system undergoing pulse-width-modulation (PWM) at the input (i.e., valve open/close action). The PWM duty cycle will be regarded as a continuous input to the proposed averaged model, and thus generated by the proposed sliding-mode controller. By adjusting the PWM duty cycle, the controller switches between seven modes of operation of the open-loop system in order to select the ones with necessary and sufficient amounts of drive energy to achieve position tracking. We will show that this results in reduced position error and valve switching activity for the actuator. The proposed control scheme is experimentally used in the position control of a pneumatic actuator and the results are presented.

Supply chains are becoming more vulnerable because of harsher and more frequent natural and man-made disasters. Supply chain disruptions now seem to occur more frequently and with more serious consequences. During and after supply chain disruptions, companies may lose revenue and incur high recovery costs. Therefore, if supply chain managers were able to better measure and manage supply chain vulnerability, they might be able to reduce the number of disruptions and their impacts. However, how to measure such risk is still an emerging topic for both research and practice. This paper presents a new interactive decision support method for measuring such risk using Value at Risk (VaR) and Conditional Value at Risk (CVaR). The proposed method, based on a disruption recovery model consisting of abrupt, linear and exponential modes, aims to help supply chain managers conduct "what-if" analyses, in order to tackle such vulnerability and other risk factors that would affect their business continuity.

For a pneumatic teleoperation system, sliding-mode control laws ensuring both transparency and low switching (open/close) activity of the valves are developed. Each pneumatic actuator has four on/off valves, thus sixteen possible combinations (“operating modes”) for the valves exist but only seven of them are both functional and unique. While previous works have focused on three-mode sliding-based position control of one pneumatic actuator, this paper develops seven-mode sliding-based bilateral control of a teleoperation system comprising a pair of pneumatic actuators. The proposed bilateral sliding control scheme is experimentally validated on a pair of actuators arranged in a force-position teleoperation architecture. The results demonstrate that leveraging the additional modes of operation leads to more efficient and smooth control of the system.

This paper presents a novel bilateral control scheme for pneumatic teleoperation systems that are actuated by low cost solenoid valves. A sliding mode control is incorporated into a two-channel, bilateral teleoperation architecture involving position-position, force-force, or force-position schemes. An analysis of stability and transparency of the closed-loop teleoperation system is carried out. The proposed control design is verified on a single-degree-of-freedom pneumatic teleoperation system with four on/off solenoid valves. Moreover, simulation results demonstrate high accuracies in terms of position and force tracking in the teleoperation system.

This paper proposes a sliding mode law for precise position control with minimal switching activity for a robotic system that uses on/off (solenoid) pneumatic actuators, For a two-chamber pneumatic actuator with four binary solenoid valves, there is a total of sixteen possible input combinations defined directly from the state of the four on/off solenoid valves present in the system. However, only seven of these discrete operating modes are considered both functional and unique. Accordingly, we use a seven-mode sliding controller that minimizes the position error using modes that have both the necessary and sufficient amounts of drive energy and, thus, involve reduced switching activity. An analysis of the closed-loop system stability is carried out. The performance of the proposed control design is experimentally verified on a single pneumatic actuator comprising of two chambers driven by four on/off solenoid valves.

This paper presents an enhanced sliding mode control for pneumatic master-slave teleoperation systems that are actuated by low-cost solenoid valves. A five-mode sliding control is incorporated into position-position, force-force, and force-position teleoperation architectures. While on/off valve pneumatic actuators have previously been modeled as having three discrete operating modes, an extension to five discrete control levels as proposed here helps to improve the actuator dynamic performance and reduce the switching activities of the valves. Stability and transparency analyses of the closed-loop teleoperation system are carried out. The proposed control design is experimentally tested on a single-degree-of-freedom pneumatic teleoperation system. Experimental results demonstrate high accuracies in terms of position and force tracking in the teleoperation system.

This paper presents the control algorithm implanted on the childbirth simulator BirthSIM in order to provide training to novice obstetricians. The forceps extraction is an obstetric manipulation learned by experience. However, nowadays the training is mainly provided during real childbirths. This kind of training could lead to dramatic consequences due to the lack of experience of some operators. This paper explains the approach that has been used to simulate the dynamic process of a childbirth on the BirthSIM simulator. We especially focus on one procedure that reproduces a difficult instrumental delivery. The recorded tractive force to extract the fetus corresponds to the literature results that confirm the realism of the simulator. The novice results emphasize the need of a childbirth simulator in order to gain initial experience without any risks.

This paper presents a new predictive hybrid control law for a pneumatic teleoperation system using solenoid valves. Based on a predictive model of the mass flow rate of the valves, this method is used within a four-channel (4CH) bilateral control architecture for haptic teleoperation. An analysis of the controller parameters is carried out in order to achieve acceptable performances. The results show that a good accuracy in position and force tracking of the teleoperation system is obtained.

This paper presents a new predictive hybrid control law for a pneumatic teleoperation system using solenoid valves. Based on a predictive model of the mass flow rate of the valves, this method is used within a four-channel (4CH) bilateral control architecture for haptic teleoperation. An analysis of the controller parameters is carried out in order to achieve acceptable performances. To evaluate the new strategy, a comparison study has been performed with a classical PWM control of a teleoperation system. The results show that the accuracy in position and force tracking in steady state but also the dynamic behavior of the pressures are better in the case of hybrid control than PWM control.

This paper presents a new available feature on the childbirth simulator BirthSIM. This feature offers a risk- free training for novice obstetricians to proceed to forceps extractions. The different forces involved during deliveries are described and modeled. The choice of a control strategy in order to reproduce all these forces is explained and argued. This paper also introduces the concepts of simple and double synchronization during deliveries. Its application allows to minimize the amount of forces exerted with forceps during an instrumental delivery to make it as safe as possible. Simulations of forceps extraction carried out by two junior obstetricians are provided and analyzed. The corresponding results are compared to the literature and to the results obtained by an expert.

Today, medical simulators are increasingly gaining attraction in clinical settings. These tools allow physicians to visualize the positions of organs, plan surgical interventions, and carry out more comprehensive post operative monitoring. A childbirth simulator provides a risk-free training and research tool for comparing various techniques that use obstetrical instruments or validating new methods. This paper presents a new teaching method to place forceps blades for obstetricians using an instrumented childbirth simulator. The proposed method is based on a physical simulator coupled with a computer graphics interface. Another aspect of this paper is to provide understanding marks to quantify the progression during a training. A first one allows to study the path in space and to quantify their repeatability, a second one allows to compute the error to a reference gesture defined by an expert. Both marks are complementary. Two novices were trained and they manage to have a more repeatable gesture and above all to become closer to a reference gesture, i.e. to reduce the injury linked to the use of forceps during instrumental deliveries.

Birth represents for each human being one the most wonderful days of his life but also one of the most dangerous. Being born in safe conditions requires to be surrounded by professionals who acquire a rigorous knowledge of diagnostic and therapeutic procedures. Nowadays, midwives and obstetricians learn mainly in delivery ward during real childbirths. For difficult childbirths, the use of obstetrical instruments (forceps, spatulas or vacuum extractors) is unavoidable. However, the use of such instruments increases the risks of lesions for the mother and the fetus. In practical, only clinical experience acquired in the delivery ward enables these risks to be reduced. Nowadays, simulators in medicine have a real appeal in the medical environment. These tools enable doctors to visualize the position of the organs in the human body, to plan their movements or to carry out a more complete post operational control. A birth simulator provides a training tool and a research tool to compare various techniques for the use of obstetrical instruments or to validate new methods. It is in this context that we have developed, in collaboration with researchers and medical doctors, a new type of instrumented forceps to offer new solutions for training obstetricians for the safe use of obstetrical forceps delivery. The main contributions of this paper are the design of instrumented forceps coupled with the BirthSIM simulator and the path analysis during the forceps blades placement. This analysis leads to the comparison of the repeatability of the movement between novice obstetricians and expert obstetricians. The results highlight the lack of teaching tool to correctly train the novice obstetricians

In this paper, the authors describe the design of a bendable robotic tip for semi-autonomous colonoscopy called COLOBOT. It is a flexible robotic manipulator made of silicone rubber in view of the compact size and biocompatibility. The outer diameter of the tip is 17 mm which is lesser than the average diameter of colon (20 mm). Three servo-valves are used to control the pressure of each chamber of this tip to obtain its flexible movement. The experimental results of this new prototype show that it can bend until 120 degrees under the pressure of 2 bar. Based on the geometric deformation and a nonlinear analysis of the silicone behavior, a direct kinematic model analogous to the forward kinematics of a conventional industrial robot kinematics chain has been put forward. The proposed kinematic model of this bendable tip is an extended model of classical models found for such a mechanism. At first a polynomial approximation is used to characterize the non linear behavior of each chamber of the actuator. Next the coupling phenomena between each chamber are highlighted through experimental tests. A new correction parameter is then proposed to take into account these interactions and a non linear optimization is made to compute this coefficient. Finally, the proposed kinematic model is experimentally validated

During the conventional procedure of the colonoscopy, there are two important movements, the introduction of colonoscope in the colon and the maneuver of the distal end. In this paper, the authors focus on a new type of automatic bendable tip while keeping the advance of the colonoscope in the colon by endoscopist. The main purpose of this tip is to make the colonoscope overcome acute intestinal bends and make easier the progression of the colonoscope for the surgeon. Firstly, we model our current prototype tip, named EDORA (distal extremity with automatic orientation). Next, the parameters of the system are estimated by using the Levenberg-Margquardt's algorithm. Finally, by using the maximum of the sensitivity function a gain margin specification is made. A set point for a position controller is designed, thus the tip can stay in the middle of the colon with disturbance rejection due to the manipulation of the colonoscope. In the same time, this controller has been designed to make the tip have some degrees of compliance to reduce the contact force due to the undesirable contact with the colon. Simulation and experimental results for the controller would be presented by emulating the real environments.

This paper deals with a new mechanical birth simulator (BirthSIM). Currently available birth simulators provide manikins that include new-born head and maternal pelvis but they do not produce the movements of the new-born in the mother's pelvis. Furthermore available maternal pelvis do not include interface pressure and are not enough realistic to simulate maternal pelvic muscles. In summary, these simulators do not help students to practice the gestures they should safely use to help the new-born in normal and at-risk situations of delivery. The originality of our mechanical birth simulator, is to provide a system to mimic the last step of the instrumental delivery, to insure a safe training of junior obstetricians and to test new techniques in obstetrics practice. The new mechanical birth simulator is composed of three parts: a physical new-born head and a maternal pelvis manikin, an interface pressure system, and a pneumatic actuator that develops an active resistance. Driven by a computer, the simulator can simulate the contractions, the interface pressure applied in the new-born head and mimic birth complications.

Deals with a comparison of sensor location and nature in the identification of physical parameters for mechanical systems with lumped elasticities. The identification model is a linear model in relation to a minimal set of parameters. The dynamic parameters are estimated by using the solution of weighted least squares of an over determined linear system obtained from the sampling of the dynamic model along a closed loop tracking trajectory. An experimental study exhibits the identification results depending on two types of sensors (position, acceleration) and different locations (motor, load).

Proposes a method to identify the joint stiffness of a robot using a bandpass filter. It is based on moving one axis at a time. The dynamic model reduces to a model which is linear in relation to a minimum set of dynamical parameters which have to be identified. These parameters are estimated using the least squares solution of an over determined linear system obtained from the sampling of the dynamic model along a closed loop tracking trajectory. Conditions for a good data processing before identification are exhibited through practical aspects concerning data sampling and data filtering. An experimental study shows the efficiency of the method with two sets of data depending on motor joint position measurements.