


Registros recuperados: 47  

 

 

 

 

 

 

 

 

 

 


Stefan Uhlar; Peter Betsch. 
We have shown that the proposed rotationless formulation of multibody dynamics is wellsuited for the energymomentum conserving integration of both openloop and closedloop multibody systems. Although the use of rotations has been completely circumvented throughout the whole discretization, jointforces can still be applied to a specific multibody system by resorting to the proposed coordinate augmentation technique. The present developments have been restricted to the planar case. However, it is important to note, that the extension to the threedimensional setting can be performed without any conceptual differences. Similarly, alternative types of joints belonging to the class of lower kinematic pairs such as cylindric joints can be easily incorporated... 
Tipo: 5 
Palavraschave: Parallel Manipulators; New Developments. 
Ano: 2008 
URL: http://www.intechopen.com/articles/show/title/conserving_integrators_for_parallel_manipulators 
 

 


Alan Lytle; Fred Proctor; Kamel Saidi. 
This chapter presented new research developments at NIST in control algorithms and controller design for parallel robots applied to Construction applications. In particular, this research focused on the NIST RoboCrane platform for automated placement of construction components. This work was the first to demonstrate the use of a laserbased site measurement system for 6 degreeoffreedom tracking of a robotic crane, and presented new methods for incorporating pose estimation errors in a compensation transform for the NIST GoMotion controller. Finally, this work presented task decomposition approaches for analyzing and automating construction crane operations based on a NIST 4D/RCS approach. 
Tipo: 1 
Palavraschave: Parallel Manipulators; Towards New Applications. 
Ano: 2008 
URL: http://www.intechopen.com/articles/show/title/control_of_cable_robots_for_construction_applications 
 

 


Massimo Callegari. 
The article has described an innovative spherical parallel wrist developed at the Polytechnic University of Marche in Ancona, revisiting all the main design steps, from kinematic synthesis up to physical prototyping. Machine kinematics has been worked out in closed form and all the singularity surfaces have been analysed: it has been pointed out that the mechanism does not possess inverse kinematics singularities, while direct kinematics singularities and translation singularities lie on the same closed surface. The inner space, where motion paths can be safely planned, has been identified and unfortunately it cannot be enlarged by kinematics optimisation because machine's Jacobian does not depend on geometrical parameters. For this reason, it was decided... 
Tipo: 9 
Palavraschave: Parallel Manipulators; New Developments. 
Ano: 2008 
URL: http://www.intechopen.com/articles/show/title/design_and_prototyping_of_a_spherical_parallel_machine_based_on_3cpu_kinematics 
 

 

 

 


Rosario Sinatra; Fengfeng Xi. 
In this chapter, the inverse dynamics of hexapods with fixedlength legs is analyzed using the natural orthogonal complement method, with considering the mass of the moving platform and those of the legs. A complete kinematics model is developed, which leads to an explicit expression for the twistmapping matrix. Based on that, the inverse dynamics equations are derived that can be used to compute the required applied actuator forces for the given movement of the moving platform. The developed method has been implemented and demonstrated by simulation. Successively, the static balancing of hexapods is addressed. The expression of the global center of mass is derived, based on which a set of static balancing equations has been obtained. It is shown that... 
Tipo: 12 
Palavraschave: Parallel Manipulators; Towards New Applications. 
Ano: 2008 
URL: http://www.intechopen.com/articles/show/title/dynamics_of_hexapods_with_fixedlength_legs 
 


Hongliang Cui; Zhenqi Zhu; Zhongxue Gan; Torgny Brogardh. 
It can be observed from the results, that Jacobian Matrix is effective with an accuracy up to 1.53 um with an input error of 1 mm (Link 1 of lower arm 1). This was verified using ADAMS simulation results. Results from NR method match very well with ADAMS simulation with a difference of only 0.06 um. Based on the DH model and an accurate Jacobian matrix, a series of results have been presented including error analysis, forward kinematic, redundant variable determination, error budget, and Jacobian approximation method. The Jacobian approximation method can be used in online control of the robot. For the TAU robot, a closed form solution of a forward kinematic problem is reached with a high accuracy instead of NR numerical solution. The simulation... 
Tipo: 13 
Palavraschave: Parallel Manipulators; New Developments. 
Ano: 2008 
URL: http://www.intechopen.com/articles/show/title/error_modeling_and_accuracy_of_tau_robot 
 
Registros recuperados: 47  


