Optimal control of a biomechanical multibody model for the dynamic simulation of working tasks

In this contribution a framework for digital human modelling using optimal control of a biomechanical multibodymodel is presented. The skeleton of the human body is represented as a multibody system, actuated by simplifiedHill muscles. Motions of the digital human model are generated by optimal control with different objective functions.The optimal control problem is discretized by the DMOCC approach, using a variational integrator for the constrainedequations of motion. With this approach, the task of "lifting of a box from a lower to a higher position" is simulatedas a test example. Both arms are modeled with seven degrees of freedom each, actuated by 29 muscles. In the optimalcontrol problem an arbitrary grasp position is included, as well as frictional contact between the box and the hand.

[1]  J. Betts.  Survey of Numerical Methods for Trajectory Optimization , 1998 .

[2]  Sigrid Leyendecker,et al.  Muscle paths in biomechanical multibody simulations , 2013 .

[3]  J. Marsden,et al.  Discrete mechanics and variational integrators , 2001, Acta Numerica.

[4]  Michael Koch,et al.  Structure Preserving Optimal Control of a Three-Dimensional Upright Gait , 2016 .

[5]  Roy Featherstone,et al.  Rigid Body Dynamics Algorithms , 2007 .

[6]  E. A. Foumeny,et al.  Rigid Body Dynamics Algorithm for Modeling Random Packing Structures of Nonspherical and Nonconvex Pellets , 2018, Industrial & engineering chemistry research.

[7]  F. Zajac.  Muscle and tendon: properties, models, scaling, and application to biomechanics and motor control. , 1989, Critical reviews in biomedical engineering.

[8]  Lorenz T. Biegler,et al.  On the implementation of an interior-point filter line-search algorithm for large-scale nonlinear programming , 2006, Math. Program..

[9]  J. Marsden,et al.  Discrete mechanics and optimal control for constrained systems , 2010 .

[10]  Sigrid Leyendecker,et al.  Biomechanical optimal control of human arm motion , 2013 .

[11]  M. Gerdts.  Optimal Control of ODEs and DAEs , 2011 .

[12]  Michael Koch,et al.  Structure Preserving Simulation of Monopedal Jumping , 2013 .

[13]  Bengt Lennartson,et al.  Enhancing Digital Human Motion Planning of Assembly Tasks Through Dynamics and Optimal Control , 2016 .

[14]  M. McCall,et al.  Rigid Body Dynamics , 2008 .

[15]  Bengt Lennartson,et al.  Inverse Dynamics for Discrete Geometric Mechanics of Multibody Systems With Application to Direct Optimal Control , 2018, Journal of Computational and Nonlinear Dynamics.

[16]  Sigrid Leyendecker,et al.  Optimal control of biomechanical motion using physiologically motivated cost functions , 2012 .