The role of the forearm (extrinsic) finger flexor muscles in initiating rotation of the metacarpophalangeal (MCP) joint and in coordinating flexion at the MCP, the proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints remains a matter of some debate. To address the biomechanical feasibility of the extrinsic flexors performing these actions, a computer simulation of the index f...

When all the inputs of a parallel manipulator (PM) are locked, the manipulator is usually turned into a structure. When an uncertainty singularity occurs for a PM, the latter structure is unstable or, in other words, it may undergo infinitesimal or finite motion. Hence, the investigation of the uncertainty singularities of a PM can be reduced to the instability analysis of its corresponding str...

This paper proposes a new family of four degrees-of-freedom (dof) parallel mechanisms with two platforms and its application to a footpad device that can simulate the spatial motions of the human foot. The new mechanism consists of front and rear platforms, and three limbs. Two limbs with 6-dof serial joints (P-S-P-P) are attached to each platform and are perpendicular to the base plate, while ...

This work deals with the modelling of lubricated revolute joints in multibody mechanical systems. In most machines and mechanisms, the joints are designed to operate with some lubricant fluid. The high pressures generated in the lubricant fluid act to keep the journal and the bearing apart. Moreover, the thin film formed by lubricant reduces friction and wear, provides load capacity and adds da...

In this paper we introduce a new technique, based on dual quaternions, for the analysis of closed linkages with revolute joints: the theory of bonds. The bond structure comprises a lot of information on closed revolute chains with a one-parametric mobility. We demonstrate the usefulness of bond theory by giving a new and transparent proof for the well-known classification of overconstrained 5R ...

This paper proposes a new control strategy for noncompliant and compliant antagonistic tendon drives. It is applied to a succession of increasingly complex single‐joint systems, starting with a linear and noncompliant system and ending with a revolute, nonlinearly tendon coupled and compliant system. The last configuration mimics the typical human joint struct...

In this paper we provide a vibration analysis model and the modeling method for a fully flexible 3-Parallel-Revolute-joint-and-Spherical-joint (3PRS) manipulator—a sliding-leg tripod with flexible links and joints. A series of tripod configurations are set by rigid kinematics for simulation and experiment. All the links are modeled by finite elements: triangular membranes combined with bending ...

Generally Kinematic and Dynamic analysis of robots are performed without modeling the flexibility of kinematic Joints, because of which the results obtained are not accurate. For better analysis and control the correct estimation and inclusion of joint effects is imminent. This paper attempts to determine the effect of joint flexibility on two link manipulator when the end effector moves in a p...

In this paper, it is studied how a certain class of physical constraints can be represented by a continuous set of orientations and how this representation is especially suitable for representing the constraints imposed by revolute and spherical joints. Further, it is shown how this can be used to represent the freedom of passive joints. It is recognised that in cooperative manipulation, the re...