Papers by Clément Gosselin
Analysis and Design of a Novel Compact Three-Degree-of-Freedom Parallel Robot
Journal of Mechanisms and Robotics
This paper introduces a novel compact three-degree-of-freedom (DOF) parallel robot that will be u... more This paper introduces a novel compact three-degree-of-freedom (DOF) parallel robot that will be used as a leg of a 9-DOF kinematically redundant parallel robot. First, the kinematic model of the robot is established based on geometric constraint conditions. Then, the inverse and forward kinematic problems are solved. The inverse problem is straightforward, while the forward problem can be solved analytically by three different approaches. Afterward, a singularity analysis is presented based on the Jacobian matrices derived from the kinematic model. The mathematical conditions for singularities are obtained and their geometric interpretation is given. Finally, the workspace of the robot is analyzed and is shown to correspond to a portion of a torus. The analysis reveals that the robot can have a singularity-free workspace of significant size relative to its footprint provided that some simple limitations are introduced at the design stage.
On the Design of an Adaptable Underactuated Hand using Rolling Contact Joints and an Articulated Palm
Journal of Mechanisms and Robotics
Based on an optimized underactuated finger using rolling contact joints, a novel prosthetic hand ... more Based on an optimized underactuated finger using rolling contact joints, a novel prosthetic hand is proposed in this article to increase the adaptability to objects of highly underactuated grippers. The hand has 17 degrees of freedom and only one degree of actuation, yielding a robust and simple control. A manually operated thumb, able to reach three stable positions corresponding to the main grasping postures, is first presented. Its rolling contact joints, introducing geometric twist and tilt, are designed in an iterative process using 3D modeled contacts. In parallel, the parameters of the thumb are optimized to maximize the distribution of contacts and the ability to hold objects. A joint located inside the hand allows the palm to arch, increasing the opposition of the ring finger and the little finger to the thumb. The floating mechanism used to distribute the single actuation to the different degrees of freedom, reduces friction while avoiding the unnecessary blocking of compo...
Robotica
This paper presents an investigation of the effectiveness of different inverse kinematics strateg... more This paper presents an investigation of the effectiveness of different inverse kinematics strategies in a context of physical human-robot interaction in which passive articulated shells are mounted on the links of a serial robot for manual guidance. The concept of passive link shells is first recalled. Then, inverse kinematics strategies that are designed to plan the trajectory of the robot according to the motion sensed at the link shells are presented and formulated. The different approaches presented all aim at interpreting the motion of the shells and provide an intuitive interaction to the human user. Damped Jacobian based methods are introduced in order to alleviate singularities. A serial 5-dof robot used in previous work is briefly introduced and is used as a test case for the proposed inverse kinematics schemes. The robot includes two link shells for interaction. Simulation results based on the different inverse kinematic strategies are then presented and compared. Finally,...
On the Design of a Three-DOF Cable-Suspended Parallel Robot Based on a Parallelogram Arrangement of the Cables
Mechanisms and Machine Science, 2017
An original design for a cable-suspended mechanism based on six cables, but actuated with three m... more An original design for a cable-suspended mechanism based on six cables, but actuated with three motors, is proposed in this paper. Each pair of cables is wound by a single actuator and their attachment points on the mobile platform and on the fixed base form a parallelogram, so that the orientation of the mobile platform remains constant while performing translational movements. First, the paper presents the architecture of the three-degree-of-freedom (three-DOF) manipulator and its corresponding kinematic equations. Then, the static workspace of the mechanism is determined analytically based on the simplification of the Jacobian matrix for a constant orientation of the mobile platform. Finally, the static workspaces of several cable arrangements are compared in order to assess the capabilities of the presented mechanism. In particular, one configuration of the three-DOF system with crossing cables is studied in more detail.
Sensors (Basel, Switzerland), 2021
Most man-made objects are composed of a few basic geometric primitives (GPs) such as spheres, cyl... more Most man-made objects are composed of a few basic geometric primitives (GPs) such as spheres, cylinders, planes, ellipsoids, or cones. Thus, the object recognition problem can be considered as one of geometric primitives extraction. Among the different geometric primitives, cylinders are the most frequently used GPs in real-world scenes. Therefore, cylinder detection and extraction are of great importance in 3D computer vision. Despite the rapid progress of cylinder detection algorithms, there are still two open problems in this area. First, a robust strategy is needed for the initial sample selection component of the cylinder extraction module. Second, detecting multiple cylinders simultaneously has not yet been investigated in depth. In this paper, a robust solution is provided to address these problems. The proposed solution is divided into three sub-modules. The first sub-module is a fast and accurate normal vector estimation algorithm from raw depth images. With the estimation ...
ASME Open Journal of Engineering, 2022
Based on the cat-righting reflex, this paper presents two reorientation maneuvers for legged robo... more Based on the cat-righting reflex, this paper presents two reorientation maneuvers for legged robots that can produce roll and pitch reorientation during free fall. In order to better describe and plan these maneuvers, two separate, but equivalent, theoretical frameworks that describe the kinematic and dynamic behavior of free-floating articulated architectures are explored and developed. A nine-degree-of-freedom quadruped robot architecture is then presented and used to demonstrate the proposed maneuvers. Finally, kinematic and dynamic simulations of this architecture are performed. The results validate the presented theoretical framework and demonstrate that both roll and pitch reorientations are obtained through the application of the presented maneuvers.
2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016
This paper presents an anticipative robot kinematic limitation avoidance algorithm for collaborat... more This paper presents an anticipative robot kinematic limitation avoidance algorithm for collaborative robots. The main objective is to improve the performance and the intuitivity of the physical human-robot interaction. One obstacle to achieve this goal is the management of limitations such as joint position limitation, singularities and collisions with the environment. Indeed, in addition to performing a given principal task, human users must pay a close attention to the manipulator configuration in order to handle the kinematic limitations. The proposed anticipative algorithm aims at relieving the human user from having to deal with such limitations. The algorithm is first presented and detailed for each individual limitation of a planar RR serial robot. The framework developed to manage several limitations occurring simultaneously is then presented. Finally, experiments are performed in order to assess the performance of the algorithm.
Humanoid Robotics: A Reference, 2017
This section discusses the use of mechanical linkages in the design of underactuated robotic hand... more This section discusses the use of mechanical linkages in the design of underactuated robotic hands. First, a literature review is provided that introduces the main contributions in this area. Then, a static analysis is briefly described, and a model that can be used for analysis and synthesis of linkage-based underactuated fingers is developed. Two examples of underactuated fingers with, respectively, two and three phalanges are then introduced in order to demonstrate the application of the model and to raise the main design issues. Examples of underactuated hands based on these underactuated fingers are then described, and some existing prototypes are presented.
Mechanisms and Machine Science, 2017
A cable suspended robot can be moved beyond its static workspace while keeping all cables in tens... more A cable suspended robot can be moved beyond its static workspace while keeping all cables in tension, by relying on end-effector inertia forces. This allows the robot capabilities to be extended by choosing suitable dynamical trajectories. In this paper, we study 3D elliptical motions, which are the most general case of spatial sinusoidal oscillations, for a robot with a point-mass end-effector and an arbitrary base architecture. We find algebraic conditions that define the range of admissible frequencies for feasible trajectories; furthermore, we show that, under certain conditions, a special frequency exists, which allows arbitrarily large oscillations to be reached. We also study transition trajectories that displace the robot from an initial state of rest (within the static workspace) to the elliptical trajectory, and vice versa.
Modeling and Development of Passively Adaptive Assistive Tools for the Assembly of Press-Fit Components
Journal of Mechanical Design, 2021
This article discusses passive mechanical architectures for accuracy correction during assembly o... more This article discusses passive mechanical architectures for accuracy correction during assembly operations. A specific solution for passive force generation with thresholds is presented. Then, the kinematics of several rotational and translational mechanisms is presented. Afterwards, a case study is introduced and the design of a prototype is presented together with some tests performed on a spark plug assembly task.
Parallel Robots: Architecture, Modeling, and Design
Encyclopedia of Robotics, 2020
As robotic systems have to solve more and more complex problems, engineers are attempting to crea... more As robotic systems have to solve more and more complex problems, engineers are attempting to create systems that can perform the largest possible set of tasks. To evaluate the needs of the system to be implemented, both the task to be accomplished and the capabilities of the robot must be considered. One critical aspect of the studies is the link between the robot and the environment/object which is the end-effector. Specialised end-effectors are the ones designed with a well defined task in mind and are task specific, as opposed to general purpose end-effectors, which aim to be robust but execute most tasks rather poorly. General purpose grippers are designed to hold a variety of objects but are increasingly required to pick objects in real-world environments in a safe manner. With this in mind, this paper studies grasping methods found in the literature to compare them and emphasize the importance of compliant/soft end-effector compared to the use of force control techniques when ...
This paper presents the performance capabilities and possible applications of a novel design of a... more This paper presents the performance capabilities and possible applications of a novel design of a robotic hand for space applications that is self-adaptive and reconfigurable. In particular the Self-Adapting Robotic Auxiliary Hand (SARAH) was developed as a potential tool for Special Purpose Dextrous Manipulator (SPDM) on the International Space Station to support increasingly complex dextrous robotic operations on the International Space Station (ISS). SARAH's simple actuation and ability to grasp a large range of geometrical shapes, makes it an ideal multi-purpose tool used for unstructured and unrehearsed ISS operations. SARAH is being developed as a collaborative effort between MD Robotics Limited and Laval University. It consists of three underactuated fingers mounted on a common structure. The fingers can envelop various shapes including cylindrical and spherical geometries. SARAH has 10 DOF and is actuated only by the two drive systems of the SPDM End Effector or the ORU ...
This paper presents two types of five-degree-of-freedom parallel mechanism generating 3T2R motion... more This paper presents two types of five-degree-of-freedom parallel mechanism generating 3T2R motion with linear inputs. The kinematic geometry of the mechanism is presented and several important kinematic issues including the inverse kinematic problem, the velocity equations and the constant orientation workspace are investigated. The main contribution of this work is the determination of the workspace using Bohemian domes. This approach provides a 3D solid model that can be built in any CAD system.
This paper introduces novel displacement-sensing link shells for the physical interaction between... more This paper introduces novel displacement-sensing link shells for the physical interaction between a human user and a serial robotic arm. The approach is inspired from the concept of macro-mini robot architecture. The framework is developed for a general multi-degree-of-freedom serial robot and a corresponding impedance control scheme is proposed. The concept is demonstrated using a five-degree-of-freedom robotic arm equipped with a six-degree-of-freedom low-impedance sensing shell that is used to control the robot. Experimental results are provided.
The dynamic analysis of novel architectures of planar and spatial spring-loaded cable-loop driven... more The dynamic analysis of novel architectures of planar and spatial spring-loaded cable-loop driven parallel mechanisms is introduced in this paper. First, the geometry of the mechanisms is briefly described and the inverse kinematic equations are given. Then, the cable forces are obtained for both the static and dynamic conditions. Due to the cable loops in the mechanisms, cables might become slack when the end-effector moves with high acceleration. Therefore, it should be verified that the cables can be maintained in tension for a certain range of trajectory frequency. Based on the static force and the Newton-Euler formulation, the natural frequencies and the corresponding ratio of the amplitudes for these two mechanisms are also found.
Foundations of Trusted Autonomy, 2018
Determination of the Inverse Kinematics Branches of Solution Based on Joint Coordinates for Universal Robots-Like Serial Robot Architecture
Journal of Mechanisms and Robotics, 2021
This paper introduces a classification of the inverse kinematics solutions (or robot postures) of... more This paper introduces a classification of the inverse kinematics solutions (or robot postures) of six degrees-of-freedom serial robots with a geometry based on or similar to Universal Robots’ arms. The solution of the inverse kinematics problem is first presented briefly, and the equations required to classify the robot postures(branches) based on the joint coordinates are then introduced.
Exploiting Redundancies for Workspace Enlargement and Joint Trajectory Optimization of a Kinematically Redundant Hybrid Parallel Robot
Journal of Mechanisms and Robotics, 2021
In this paper, possibilities for workspace enlargement and joint trajectory optimization of a (6 ... more In this paper, possibilities for workspace enlargement and joint trajectory optimization of a (6 + 3)-degree-of-freedom kinematically redundant hybrid parallel robot are investigated. The inverse kinematic problem of the robot can be solved analytically, which is a desirable property of redundant robots, and is implemented in the investigations. A new method for detecting mechanical interferences between two links which are not directly connected is proposed for evaluating the workspace. Redundant degrees-of-freedom are optimized in order to further expand the workspace. An approach for determining the desired redundant joint coordinates is developed so that a performance index can be minimized approximately when the robot is following a prescribed Cartesian trajectory. The presented approaches are readily applicable to other kinematically redundant hybrid parallel robots proposed by the authors.
Stiffness Matrix of Compliant Parallel Mechanisms
Advances in Robot Kinematics: Analysis and Design, 2008
Starting from the definition of a stiffness matrix, the authors present the Cartesian stiffness m... more Starting from the definition of a stiffness matrix, the authors present the Cartesian stiffness matrix of parallel compliant mechanisms. The proposed formulation is more general than any other stiffness matrix found in the literature since it can take into account the stiffness of the passive joints and remains valid for large displacements. Then, the conservative property, the validity,and the positive definiteness of this matrix are discussed.
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Papers by Clément Gosselin