This paper presents a follow-the-leader algorithm for serpentine control of hyper-redundant manipulators. Given an obstacle-free trajectory for the manipulator tip generated by a path planner or teleoperation, the follow-the-leader algorithm ensures whole-arm collision avoidance by forcing ensuing links to follow the same trajectory. The algorithm requires two steps to place the tip on each tra...

Abstract— In this paper, the design of a hip joint of an exoskeleton is presented so as to automatically assist the hip joint motion of a physically weak person. A spherical three-degrees-of-freedom parallel mechanism is used for the purpose. The problem is framed as an optimization problem with an objective of determining the proper connection points for the links of the structure at the human...

The aim of this work is to characterize the regularity and variability of human arm movements. The arm posture is quantified by a swivel angle that is experimentally measured when a healthy subject is reaching for targets in a spherical workspace. It is shown that without specific instruction, a subject moving his/her arm tends to use a consistent arm posture with small variations when reaching...

Operation of underground coal mine mobile equipment is usually done in a restricted workspace with reduced visibility. This work environment puts machine operators in awkward postures for tasks that require awareness of their surroundings and fast reactions to avoid hazardous situations. Using experienced equipment operators as a source, researchers conducted an investigation that developed a m...

in this research work, a novel parallel manipulator with high positioning and orienting rate is introduced. this mechanism has two rotational and one translational degree of freedom. kinematics and jacobian analysis are investigated. moreover, workspace analysis and optimization has been performed by using genetic algorithm toolbox in matlab software. because of decreasing moving elements, it i...

Surgery is one of the fields where robots have been introduced due to their positioning accuracy which exceed the human capabilities. Parallel robots offer higher stiffness and smaller mobile mass than serial ones, thus allowing faster and more precise manipulations that fit medical applications. In the paper is presented the modeling and simulation of a new parallel robot, based on an innovati...

Two different visual servoing controls have been developed to govern a translating parallel manipulator with an eye-in-hand configuration, That is, a position-based and an image-based controller. The robot must be able to reach and grasp a target randomly positioned in the workspace; the control must be adaptive to compensate motions of the target in the 3D space. The trajectory planning strate...

The paper aims to analyze the kinematics of a three-degreeof-freedom (3-DOF) in-parallel actuated mechanism, which can be used as a wrist robotic device. Basic kinematic models are given. Due to symmetry in mechanism geometry, the input-output polynomial degree derived in position forward kinematics can be considerably reduced. By analyzing the relationship between the independent and dependent...

ABSTRACT This paper deals with the sensitivity analysis of 3-RPR planar parallel manipulators (PPMs). First, the sensitivity coefficients of the pose of the manipulator moving platform to variations in the geometric parameters and in the actuated variables are expressed algebraically. Moreover, two aggregate sensitivity indices are determined, one related to the orientation of the manipulator m...