Sir Robert Stawell Ball and methodologies of modern screw theory

Author(s):  
H Lipkin ◽  
J Duffy

The theory of screws was largely developed by Sir Robert Stawell Ball over 100 years ago to investigate general problems in rigid body mechanics. Nowadays, screw theory is applied in many different but related forms including dual numbers, Plilcker coordinates and Lie algebra. An overview of these methodologies is presented along with a perspective on Ball. Screw theory has re-emerged after a hiatus to become an important tool in robot mechanics, mechanical design, computational geometry and multi-body dynamics.

Author(s):  
Francesco Braghin ◽  
Paolo Pennacchi ◽  
Edoardo Sabbioni

The dynamic behavior of the human body during race car maneuvers and frontal crash tests is analyzed in this paper. Both the vehicle and the human body have been modeled using the multi-body approach. Two commercial codes, BRG LifeMOD Biomechanics Modeler®, for the simulation of the human body dynamics, and MSC ADAMS/Car® for the modeling of the vehicle behavior, have been used for the purpose. Due to the impossibility of co-simulating, at first the accelerations on the driver’s chassis are determined using the vehicle’s multibody code and approximating the driver as a rigid body. Then, the calculated accelerations are applied to the vehicle chassis in the biomechanics code to assess the accelerations in various significant points on the driver.


2013 ◽  
Vol 756-759 ◽  
pp. 3021-3029
Author(s):  
Jie Li ◽  
Hong Lei An ◽  
Xue Qiang Gu ◽  
Hong Tao Xue

General pseudospectral method is extended to Lie group by virtue of equivariant map for solving rigid dynamics on Lie group. In particular, for the problem of structural characteristics of the dynamics system can not be conserved by using general pseudospectral method directly on Lie group, the differential equation evolving on the Lie group is transformed to an equivalent differential equation evolving on a Lie algebra on which general pseudospectral method is used, so that the numerical flow of rigid body dynamics is ensured to stay on Lie group. Furthermore, structural conservativeness and numerical stabilities of this method are validated and analyzed by simulation on a 3D pendulum in comparison with using pseudospectral method directly on Lie group.


2014 ◽  
Vol 989-994 ◽  
pp. 3037-3040
Author(s):  
Xiao He Deng

Based on the theory of gear dynamics and contact, the paper uses multi-rigid-body dynamics software ADAMS to build transmission simulation model. The model takes the highest shift gears of a transmission as objects to finish gear meshing simulation analysis. The corresponding meshing force and its Fourier transform results are acquired based on the analysis to get the transmission gears meshing properties.


2012 ◽  
Vol 09 (04) ◽  
pp. 1250029 ◽  
Author(s):  
JINGGUO WANG ◽  
YANGMIN LI

Based on the screw theory and Lie group notations, this paper presents a modeling method for a kind of wheeled humanoid robot whose upper human-like body is mounted on the top of a mobile platform with three wheels. By combining the reciprocal product of the twist and wrench with Jourdain variation principle, a general formulation method is proposed to model the whole system's dynamics that represents directly the relationship between the input and the resultant external and inertial wrench. Both the system kinematics and dynamics are derived carefully. The simulations are made to verify the proposed modeling methodology and the simulation results are also compared with the results obtained from the multi-body dynamics software.


Author(s):  
Firdaus E Udwadia ◽  
Phailaung Phohomsiri

The power of the new equations of motion developed in part I of this paper is illustrated using three examples from multi-body dynamics. The first two examples deal with the problem of accurately controlling the orientation of a rigid body, while the third example deals with the synchronization of two rigid bodies so that their relative orientations are ‘locked’ through prescribed dynamical relationships. The ease, simplicity and accuracy with which control of such highly nonlinear systems is achieved are demonstrated.


2011 ◽  
Vol 188 ◽  
pp. 487-492 ◽  
Author(s):  
Q.J. Yang ◽  
D.N. Li ◽  
L.L. Kong ◽  
K. Li

In modern machining processes, Gantry Machining Center is one of the most important machine tools. Moreover, beam components directly relate to the overall performance. From multi-body simulation (MBS) and finite element analysis (FEA) respectively, the paper discusses current state of the multi-body dynamics modelling of the machine tool components in domestic and overseas. In this paper, We adopt a method, the multi-flexible body dynamics(MFBD) modeling method for machine tool transmission components (linear guidance and ball screw drives) in software Recurdyn, to create the conditions for MFBD simulation analysis of the beam components system. Much more, it provides a way of MFBD modelling for machine tools components in both the high-speed and high-performance.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Jie Li ◽  
Honglei An ◽  
Huayong Zhu ◽  
Lincheng Shen ◽  
Bin Fang

General pseudospectral method is extended to the special Euclidean group SE(3) by virtue of equivariant map for rigid-body dynamics of the aircraft. On SE(3), a complete left invariant rigid-body dynamics model of the aircraft in body-fixed frame is established, including configuration model and velocity model. For the left invariance of the configuration model, equivalent Lie algebra equation corresponding to the configuration equation is derived based on the left-trivialized tangent of local coordinate map, and the top eight orders truncated Magnus series expansion with its coefficients of the solution of the equivalent Lie algebra equation are given. A numerical method called geometric pseudospectral method is developed, which, respectively, computes configurations and velocities at the collocation points and the endpoint based on two different collocation strategies. Through numerical tests on a free-floating rigid-body dynamics compared with several same order classical methods in Euclidean space and Lie group, it is found that the proposed method has higher accuracy, satisfying computational efficiency, stable Lie group structural conservativeness. Finally, how to apply the previous discretization scheme to rigid-body dynamics simulation and control of the aircraft is illustrated.


2016 ◽  
Vol 47 (7) ◽  
pp. 775-782
Author(s):  
Vladimir Alekseevich Shvilkin

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