On Animating Whip-type Motions

This paper presents algorithmic methods to generate progressive, whip-type motions, characteristic of experienced humans in high speed athletic activities like throwing and striking. In deriving these methods, we deduce boundary conditions for dynamic quantities by analyzing the motion of a two-link system. A control algorithm based on cascading gains is introduced and is shown to be e cient when compared to xed-gain proportional control. Principles of energy redistribution within links are used to explain the mechanical advantage gained by a whip-type motion, and the e ciency of cascading gain control. The results can be applied in motion synthesis for animation which is demonstrated through simulation of a multi-link system. Our aim has been to obtain biomechanically plausible solutions which approximate natural motions.

[1]  Michael F. Cohen,et al.  Interactive spacetime control for animation , 1992, SIGGRAPH.

[2]  Carol Anne Putnam,et al.  Segment interaction in selected two-segment motions , 1981 .

[3]  Joseph K. Kearney,et al.  Efficient Generation of Whip-Like Throwing and Striking Motions , 1993 .

[4]  Robert J. Schilling,et al.  Fundamentals of robotics - analysis and control , 1990 .

[5]  S. Aleshinsky.  An energy 'sources' and 'fractions' approach to the mechanical energy expenditure problem--V. The mechanical energy expenditure reduction during motion of the multi-link system. , 1986, Journal of biomechanics.

[6]  A. J. Cochran,et al.  The search for the perfect swing , 1968 .

[7]  M. A. Lampsa.  Maximizing Distance of the Golf Drive: An Optimal Control Study , 1975 .

[8]  S Y Aleshinsky,et al.  An energy 'sources' and 'fractions' approach to the mechanical energy expenditure problem--IV. Criticism of the concept of 'energy transfers within and between links'. , 1986, Journal of biomechanics.

[9]  J. F. Cremer,et al.  An Architecture for General Purpose Physical System Simulation-Integrating Geometry, Dynamics, and Control , 1990 .

[10]  Andrew P. Witkin,et al.  Spacetime constraints , 1988, SIGGRAPH.

[11]  S Y Aleshinsky,et al.  An energy 'sources' and 'fractions' approach to the mechanical energy expenditure problem--III. Mechanical energy expenditure reduction during one link motion. , 1986, Journal of biomechanics.

[12]  D. Winter,et al.  Transfers of mechanical energy within the total body and mechanical efficiency during treadmill walking. , 1980, Ergonomics.

[13]  Eugene Fiume,et al.  Reusable motion synthesis using state-space controllers , 1990, SIGGRAPH.

[14]  Theodore P. Jorgensen.  On the Dynamics of the Swing of a Golf Club , 1970 .

[15]  B Elliott,et al.  A three-dimensional kinematic method for determining the effectiveness of arm segment rotations in producing racquet-head speed. , 1994, Journal of biomechanics.

[16]  E. Kreighbaum,et al.  Biomechanics: A Qualitative Approach for Studying Human Movement , 1981 .

[17]  P R Cavanagh,et al.  A biomechanical analysis of the karate chop. , 1976, Research quarterly.