We give an exposition of Plücker vectors for a system of joint axes in projective 3-space. We use Plücker vectors to analyze dependencies among joint axes and in particular to show that two rotational joints rigidly joined by a bar and each with 3 degrees of freedom always form a 5-dimensional system. We introduce the concept of reduced redundancy in a dependent set of projective Lines and argu...

Although locomotor kinematics in walking and running birds have been examined in studies exploring many biological aspects of bipedalism, these studies have been largely limited to two-dimensional analyses. Incorporating a five-segment, 17 degree-of-freedom (d.f.) kinematic model of the ostrich hind limb developed from anatomical specimens, we quantified the three-dimensional (3-D) joint axis a...

This paper formulates and solves the design equations for three degree-of-freedom spatial serial chains constructed with two revolute (R) joints and one prismatic (P) joint. Previous work has shown that equating the kinematics equations of the chain to a set of end-effector positions yields 24 equations in 25 unknowns, which means one of the design parameters can be chosen arbitrarily. Here it ...

In this paper we develop two noble mechanisms for im proving the motions of humanoid robots The double spherical joint is a six DOF joint that consists of six sin gle DOF mechanical pairs in series with their axes inter secting at a point The double spherical joint replaces two hip joints six DOF of humanoid robot and even provides the equivalent function of waist joints without actually adding...

In the presented work model and experiments of compliant robots with piezo actuators are carried out. The robot is designed to perform automatic injection of cells in the range of 10-30 μm. A kinematics model of serial-parallel structures is presented. Pseudo rigid body approach is used, where the elastic joints are modelled as revolute joints. Models for tension of parallel structures with ela...

Orientation of the subtalar joint axis dictates inversion and eversion movements of the foot and has been the focus of evolutionary and clinical studies for a number of years. Previous studies have measured the subtalar joint axis against the axis of the whole foot, the talocrural joint axis and, recently, the principal axes of the talus. The present study introduces a new method for estimating...

ion is a very important feature when thinking about industrial machine programming. Code abstraction makes possible generalize implementation reaching high code re-use and less memory allocation. This abstract programming way makes feasible and easy, merge code from isolated software packages to new and specialized applications fields. With an abstract modelling of basic mechanisms structures l...

steel structures are usually built with some defects. according to the standard building codes, the central axes of the bracing members should go through the beam-column joints, however, in most of the braced steel structures, bracing members are unintentionally connected eccentrically. this paper presents a numerical investigation on performance analysis of cbfs (concentrically braced frames) ...

This paper presents an ICP-based algorithm for tracking an articulated skeletal model of the human body (stick figure) in 3D. The data are 3D points distributed roughly around the limbs’ medial axes. The algorithm fits each stick to a limb in a hierarchical fashion, traversing the body’s kinematic chain, while preserving the connection of the sticks at the joints. Experimental results illustrat...