Damien Charles Chablat

French National Centre for Scientific Research | CNRS · Institut des sciences de l'ingénierie et des systèmes (INSIS)

The optimization of parallel kinematic manipulators (PKM) involve several constraints that are difficult to formalize, thus making optimal synthesis problem highly challenging. The presence of passive joint limits as well as the singularities and self-collisions lead to a complicated relation between the input and output parameters. In this article...

Piping inspection robots play an essential role for industries as they can reduce human effort and pose a lesser risk to their lives. Generally, the locomotion techniques of these robots can be classified into mechanical and bioinspired. By using slot-follower leg mechanisms, DC-motors, and control units, a rigid caterpillar type inspection robot w...

In a human-robot interaction system, the most important thing to consider is the safety of the user. This must be guaranteed in order to implement a reliable system. The main objective of this paper is to generate a safe motion scheme that takes into account the obstacles present in a virtual reality (VR) environment. The work is developed using th...

The use of an endoscope in otological surgery as compared to using a microscope provides many benefits in terms of visibility and access to the operating region. The disadvantage of using an endoscope is that it has to be handled by the surgeon during the surgery. A novel parallel kinematic mechanism has been proposed recently for manipulating the...

From the list of interfaces used in virtual reality systems, haptic interfaces allow users to touch a virtual world with their hands. Traditionally, the user's hand moves the end-effector of a robotic arm. When there is no contact in the virtual world, the robotic arm is passive; when there is contact, the arm suppresses mobility to the user's hand...

This work proposed the design of a simple, robust and inexpensive motion transmission for hand prostheses. The main challenge to be solved is to generate not only fast movements for the closing of the fingers during the grasping but also important forces to hold these objects. A Two-Speed Load Adaptive Variable Transmission is introduced to solve t...

In this article a multi-segmented planar tensegrity mechanism was presented. This mechanism has a three-segment structure with each segment residing on top of another. The size of the segments may decrease proportionally from base to top, resulting in a tapered shape from base to tip like an elephant trunk. The system was mechanically formulated as...

Cuspidal robots can travel from one inverse kinematic solution (IKS) to another without meeting a singularity. This property can be analyzed by understanding the inverse kinematic model (IKM) as well as the singularities in the joint space and in the workspace. In this article, we revisit the geometrical interpretation of the IKM with conics. The c...

In this paper, a robot with parallel architecture is proposed for charging an electric vehicle having the charging socket on its front side. Kinematic models are developed to design the robot for a given workspace that corresponds to the car's plug placements. A demonstrator composed by commercial components is shown.

Cuspidal robots are robots with at least two inverse kinematic solutions that can be connected by a singularity-free path. Deciding the cuspidality of a generic 3R robots has been studied in the past, but extending the study to six-degree-of-freedom robots can be a challenging problem. Many robots can be modeled as a polynomial map together with a...

For haptic interaction, a user in a virtual environment needs to interact with proxies attached to a robot. The device must be at the exact location defined in the virtual environment in time. However, due to device limitations, delays are always unavoidable. One of the solutions to improve the device response is to infer human intended motion and...

The optimization of parallel kinematic manipulators (PKM) involve several constraints that are difficult to formalize, thus making optimal synthesis problem highly challenging. The presence of passive joint limits as well as the singularities and self-collisions lead to a complicated relation between the input and output parameters. In this article...

In a human-robot interaction system, the most important thing to consider is the safety of the user. This must be guaranteed in order to implement a reliable system. The main objective of this paper is to generate a safe motion scheme that takes into account the obstacles present in a virtual reality (VR) environment. The work is developed using th...

Cuspidal robots can travel from one inverse kinematic solution to another without meeting a singularity. The name cuspidal was coined based on the existence of a cusp point in the workspace of 3R serial robots. The existence of a cusp point was proved to be a necessary and sufficient condition for orthogonal robots to be cuspidal, but it was not po...

The paper focuses on the stiffness analysis of multi-link serial planar manipulators, which may demonstrate nonlinear stiffness behavior under the compressive loading. Two important cases are considered, where the manipulator has either a straight or non-straight initial configuration. It was proved that in the first case the loading may cause the...

The paper focuses on the stiffness analysis of multi-link serial planar manipulators, which may demonstrate nonlinear stiffness behavior under the compressive loading. Two important cases are considered, where the manipulator has either a straight or non-straight initial configuration. It was proved that in the first case the loading may cause the...

Cuspidal robots can travel from one inverse kinematic solution to another without meeting a singularity. The name cuspidal was coined based on the existence of a cusp point in the workspace of 3R serial robots. The existence of a cusp point was proved to be a necessary and sufficient condition for orthogonal robots to be cuspidal, but it was not po...

Musculoskeletal disorder (MSD) is one of the major health problems in physical work especially in manual handling jobs. In several literatures, muscle fatigue is considered to be closely related to MSD, especially for muscle related disorders. In addition to many existing analysis techniques for muscle fatigue assessment and MSD risk analysis, in t...

The paper deals with the equilibrium configurations and their stability study of a new type of compliant tensegrity mechanism based on dual-triangle structures, which actuated by adjusting elastic connections between the triangle edges. For a single segment of such mechanism, the torque-deflection relation was obtained as a function of control inpu...

In otolaryngologic surgery, more and more robots are being studied to meet the clinical needs of operating rooms. However, to help design and optimize these robots, the workspace must be precisely defined taking into account patient variability. The aim of this work is to define a geometric atlas of the middle ear and paranasal sinuses for endoscop...

In otolaryngologic surgery, more and more robots are being studied to meet the clinical needs of operating rooms. However, to help design and optimize these robots, the workspace must be precisely defined taking into account patient variability. The aim of this work is to define a geometric atlas of the middle ear and paranasal sinuses for endoscop...

This paper presents a novel three-degree-of-freedom (3-DOF) translational parallel manipulator (TPM) by using a topological design method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations. The proposed PM is only composed of lower-mobility joints and actuated prismatic joints, together with the investigatio...

In otolaryngologic surgery, endoscopy is increasingly used to provide a better view of hard-to-reach areas and to promote minimally invasive surgery. However, the need to manipulate the endoscope limits the surgeon's ability to operate with only one instrument at a time. Currently, several robotic systems are being developed, demonstrating the valu...

In otolaryngologic surgery, endoscopy is increasingly used to provide a better view of hard-to-reach areas and to promote minimally invasive surgery. However, the need to manipulate the endoscope limits the surgeon's ability to operate with only one instrument at a time. Currently, several robotic systems are being developed, demonstrating the valu...

The paper focuses on the redundancy resolution in kinematic control of a new type of serial manipulator composed of multiple tensegrity segments, which are moving in a multi-obstacle environment. The general problem is decomposed into two sub-problems, which deal with collision-free path planning for the robot end-effector and collision-free motion...

In the list of interfaces used to make virtual reality, haptic interfaces allow users to touch a virtual world with their hands. Traditionally, the user’s hand touches the end effector of a robotic arm. When there is no contact, the robotic arm is passive; when there is contact, the arm suppresses mobility to the user’s hand in certain directions....

This article presents a new hand architecture with three under-actuated fingers. Each finger performs spatial movements to achieve more complex and varied grasping than the existing planar-movement fingers. The purpose of this hand is to grasp complex-shaped workpieces as they leave the machining centres. Among the taxonomy of grips, cylindrical an...

In the list of interfaces used to make virtual reality, haptic interfaces allow users to touch a virtual world with their hands. Traditionally, the user’s hand touches the end effector of a robotic arm. When there is no contact, the robotic arm is passive; when there is contact, the arm suppresses mobility to the user’s hand in certain directions....

This article presents the actuation strategy of a 2-DOF tensegrity type mechanism that employs three tension springs and a passive universal joint. This mechanism is proposed to be incorporated as an articulation unit for a piping inspection robot in order to overcome pipe bends and junctions. In the event of a junction, external actuations are req...

The paper focuses on the redundancy resolution in kinematic control of a new type of serial manipulator composed of multiple tensegrity segments, which are moving in a multi-obstacle environment. The general problem is decomposed into two sub-problems, which deal with collision-free path planning for the robot end-effector and collision-free motion...

The paper focuses on the stiffness modeling of a new type of compliant manipulator and its non-linear behavior while interacting with the environment. The manipulator under study is a serial mechanical structure composed of dualtriangle segments. The main attention is paid to the initial straight configuration which may suddenly change its shape un...

The paper deals with the elastostatic modeling of multi-link flexible manipulator based on dual-triangle tensegrity mechanism and its non-linear behavior under external loading. The main attention is paid to the static equilibriums and the manipulator stiffness behavior under the loading for the arbitrary initial configuration. It was proved that t...

Football, as the most popular sport in the world, has a very wide spread worldwide. With the wide spread of football, more and more people participate in football activities. Football is a very strenuous sport and athletes are easily injured. This article examines the problem of kicking through two experiments, one is the normal kicking process, an...

This paper is devoted to the control and identification of a manipulator with three anti-parallelogram joints in series, referred to as X-joints. Each X-joint is a tensegrity one-degree-of-freedom mechanism antagonistically actuated with cables and springs in parallel. As compared to manipulators built with simple revolute joints in series, manipul...

This article presents a new hand architecture with three under-actuated fingers. Each finger performs spatial movements to achieve more complex and varied grasping than the existing planar-movement fingers. The purpose of this hand is to grasp complex-shaped workpieces as they leave the machining centres. Among the taxonomy of grips, cylindrical an...

This paper presents a novel three-degree-of-freedom (3-DOF) translational parallel manipulator (TPM) by using a topological design method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations. The proposed PM is only composed of lower-mobility joints and actuated prismatic joints, together with the investigatio...

This paper presents the kinematic design of a translational parallel mechanism (PM) named Vari-Orthoglide by means of the workspace superposition, according to the sub-kinematic chain (SKC) based PM composition principle. The main topological characteristics of the manipulator with two SKCs under study, such as the position and orientation (POC) ch...

During Otologic surgery, and more broadly during microsurgery, the surgeon encounters several difficulties due to the confined spaces and micro-manipulations. The purpose of the paper is to design a robot with a prescribed regular workspace shape to handle an endoscope to assist the Otologic surgery. A spherical parallel mechanism with two degrees...

The paper focuses on the kinematics control of a compliant serial manipulator composed of a new type of dualtriangle elastic segments. Some useful optimization techniques were applied to solve the geometric redundancy problem, ensure the stability of the manipulator configurations with respect to the external forces/torques applied to the endeffect...

For fast-moving robot systems, the fluctuating dynamic loads transmitted to the supporting frame can excite the base and cause noise, wear, and fatigue of mechanical components. By reducing the shaking force completely, the dynamic characteristics of the robot system can be improved. However, the complete inertial force and inertial moment balancin...

This article presents an optimization approach for the design of a piping inspection robot. A rigid bio-inspired piping inspection robot that moves like a caterpillar was designed and developed at LS2N, France. By the addition of tensegrity mechanisms between the motor modules, the mobile robot becomes flexible to pass through the bends. However, t...

The paper focuses on the kinematics control of a compliant serial manipulator composed of a new type of dual-triangle elastic segments. Some useful optimization techniques were applied to solve the geometric redundancy problem, ensure the stability of the manipulator configurations with respect to the external forces/torques applied to the end-effe...

This article analyzes the singularities and workspace of two tensegrity mechanisms that employ a passive universal joint and either three or four tension springs. These two architectures are correlated to 3-SPS-U and 4-SPS-U parallel mechanisms for determining their geometric equations. By fixing the limits of prismatic joints, the workspace for th...

The paper focuses on the mechanics of a compliant serial manipulator composed of new type of dual-triangle elastic segments. Both the analytical and numerical methods were used to find the manipulator stable and unstable equilibrium configurations, as well as to predict corresponding manipulator shapes. The stiffness analysis was carried on for bot...

The shaking force balancing is a well-known problem in the design of high-speed robotic systems because the variable dynamic loads cause noises, wear and fatigue of mechanical structures. Different solutions, for full or partial shaking force balancing, via internal mass redistribution or by adding auxiliary links were developed. The paper deals wi...

Crutch is the most common tool for temporary or permanent ambulation assistance. Crutch-using transforms human kinematic chain, and therefore is hypothesized to have dynamical influence on the trunk. In this paper, two different crutch gaits were analyzed with regard to their associated risks of scoliosis. A numerical human-crutch model was constru...

As a traditional tool of external assistance, crutches play an important role in society. They have a wide range of applications to help either the elderly and disabled to walk or to treat certain illnesses or for post-operative rehabilitation. But there are many different types of crutches, including shoulder crutches and elbow crutches. How to ch...

This paper deals with the joint space and workspace analysis of a two degree of freedom spherical parallel mechanism designed to be used to handle an endoscope. This mechanism is composed of the three legs (2USP-U) to connect the base to a moving platform. As the manipulator can get up to six solutions to the direct kinematic problem (DKP) in four...

The paper deals with the stiffness analysis and stability study of equilibrium configurations for dual-triangle tensegrity mechanism, which is actuated by adjusting elastic connections between the triangle edges. For this mechanism, the torque-deflection relation was obtained as a function of control inputs and geometric parameters. It was proved t...

This article presents an optimization approach for the design of an inspection robot that can move inside variable diameter pipelines having bends and junctions. The inspection robot uses a mechanical design that mimics the locomotion of a caterpillar. The existing prototype developed at LS2N, France is a rigid model that makes it feasible for work...

The paper deals with the shaking force balancing of the DELTA robot. The balancing of the shaking force of the DELTA robot is carried out through the center of mass acceleration minimization. The trajectories of the total mass center of moving links are defined as straight lines between the initial and final positions of the platform. Then, the mot...