Showing papers in "Mechanism and Machine Theory in 2003"

TL;DR: In this paper, an approach based on the theory of screws and on the principle of virtual work is proposed to calculate the actuator forces as a function of the external applied forces and the imposed trajectory.

TL;DR: The term kinematic structure encompasses all those characteristics of mechanisms which are determined solely by the pattern of interconnection among the constituent links of the mechanism and hence are independent of metric properties of the mechanisms as discussed by the authors.

TL;DR: In this paper, the direct kinematics solutions for a novel 3-PRS parallel mechanism are presented, where the geometric method is applied to formulate three coupled trigonometric equations.

TL;DR: A reference table created by investigating the mechanical characteristic and the differences between 16 patented laparoscopic surgical devices will benefit engineers, designers, and students in analyzing the mechanical subsystems used in surgical instruments and suggest alternative options available for replacing existing designs.

TL;DR: In this article, the nonlinear dynamics of a planetary gear system with multiple clearances taken into account are investigated. And the solutions are determined by using harmonic balance method from the equations in matrix form.

TL;DR: In this paper, a variational approach for planning singularity-free path-planning for parallel manipulators based on a Lagrangian incorporating both a kinetic energy term which keeps the path short and a potential energy term that ensures that the obtained path is singularity free and the actuator lengths remain within their prescribed limits.

TL;DR: In this article, a four contact-point bearing with one row of ball bearings was discussed under general load conditions (moment, axial load, and radial load) and the load distribution in two contact point rolling elements was calculated.

TL;DR: In this paper, a mathematical dynamic model is derived for compliant, constant-force compression mechanisms, based on the pseudo-rigid-body model simplification of the device, which allows every configuration to be represented by the same model, so a separate treatment is not required for each configuration.

TL;DR: A comprehensive volumetric kinematics error model that relates all kinematic error sources in the manipulator’s architecture to the pose errors of the end-effector is derived for HexaSlide type parallel manipulators.

TL;DR: In this article, an elastic, dynamic model with worn teeth having two degrees of freedom has been developed, based on the rigid model with only one-degree of freedom, and the dynamic coefficient was then determined using this new model, and by referring to the changeable gear ratio, the teeth rigidity, the normal backlash, the friction force and the mass moments of inertia in the power transmission.

TL;DR: In this paper, an approach is presented for automatically generating inverse dynamic solutions for planar parallel manipulators with 3-DOF and spatial parallel manipulator with 6-DoF to eliminate the errors and tedium associated with hand derivations.

TL;DR: In this paper, it is shown that the 3-UPU wrist may reach singular configurations in which the spherical constraint between the end effector and the frame fails. And the singularity condition, that makes it possible to find all the 3 UPU wrist's singular configurations, is written in explicit form and is geometrically interpreted.

TL;DR: In this paper, failure analysis of parallel and serial manipulators is presented and classified based on the component, subsystem, and system failures, and two criteria are defined for the identification of optimum configurations of parallel manipulators with one redundant actuation.

TL;DR: In this paper, a model is developed to analyze the load distribution of ball screws with geometry errors, and the results demonstrate that the negative geometry errors of the ball screw result in the decrease of the load on balls or guiding grooves, and when the negative errors reach certain value there is no contact between the balls and the groove.

TL;DR: In this article, the kinematics and dynamics analysis of a 6-degree-of-freedom RTS fully parallel manipulator with elastic joints is presented. And the effect of the elastic moment in dynamic analysis is investigated by only using the vector operation.

TL;DR: In this paper, the reliability-based design of gear pairs has been investigated using the techniques from perturbation method and reliability based design theory, and the theoretical formulae of the reliability of the gear pairs are obtained.

TL;DR: In this paper, the forward kinematics of the general Stewart-Gough platform using dialytic elimination is presented, which leads to a 40th degree univariate equation from a constructed 15×15 Sylvester's matrix which is relatively small in size.

TL;DR: In this article, the authors classify all architecturally singular planar parallel manipulators and show that they are projectively invariant, i.e., they are movable and satisfy an assembly condition.

TL;DR: The application of a design space reduction technique decreases considerably the computational cost and makes the problem affordable and the efficiency of the combined gross-fine search method proves.

TL;DR: In this article, the authors present a fast and reliable method of designing isotropic 6-DOF parallel manipulators, which can be easily developed from an isotropy generator, which consists of six straight lines satisfying the isotropy conditions.

TL;DR: In this paper, the authors focus their attention on the gaits of animals and the energy they consume for locomotion, with the hope that engineers trying to design and develop legged robots would find such information useful.

TL;DR: In this article, a non-planar dynamic modeling and analysis of the spindle-disk system equipped with an Automatic Ball-type Balancer (ABB) system for optical disk drives is presented.

TL;DR: In this paper, the dynamic behavior of a hybrid actuator is studied by applying numerical simulation on the whole system, and Lagrangian mechanics is applied to derive equations of motion.

TL;DR: In this article, a new method for dynamic calculation of mobile cranes has been developed, where the flexible multibody model of the structure of a crane is coupled with the model of its drive system.

TL;DR: In this paper, quantitative measures are developed in a very simple way, using some of the principles of the genetic process to test isomorphism and to know relatively the characteristics like speed ratios and transmission efficiency.

TL;DR: In this article, a robust controller design based on the second method of Lyapunov using simple quantitative bounds on the model uncertainties is illustrated for use during the trajectory tracking phase in multi-link manipulator control.

TL;DR: In this paper, the orientation capability of a serial manipulator is investigated by examining the rotatability of its equivalent mechanism and by proposing the workspace region decomposition, based on the polynomial discriminant derived from the virtual angle analysis of the end-effector link of the equivalent mechanism.

TL;DR: In this paper, a radial basis neural network (NN) was employed to predict the amplitude of acceleration for different road conditions such as concrete, waved stone block paved and country roads.

TL;DR: In this article, position analysis in analytical form of the Assur group of class 3 and order 3 with four links and six revolute/prismatic joints (triad) is presented.

TL;DR: Closure-equation algebra and deployment of prior findings allow us to begin a comprehensive search for mobile six-bar loops and name many solutions with parallel adjacent joint-axes and specify those chains which require further study.