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Selected Works

Antonie J. van den Bogert

Optimal control

Articles 1 - 4 of 4

Full-Text Articles in Mechanical Engineering

Optimality Principles For Model-Based Prediction Of Human Gait, Marko Ackermann, Antonie J. Van Den Bogert Dec 2013

Optimality Principles For Model-Based Prediction Of Human Gait, Marko Ackermann, Antonie J. Van Den Bogert

Antonie J. van den Bogert

Although humans have a large repertoire of potential movements, gait patterns tend to be stereotypical and appear to be selected according to optimality principles such as minimal energy. When applied to dynamic musculoskeletal models such optimality principles might be used to predict how a patient's gait adapts to mechanical interventions such as prosthetic devices or surgery. In this paper we study the effects of different performance criteria on predicted gait patterns using a 2D musculoskeletal model. The associated optimal control problem for a family of different cost functions was solved utilizing the direct collocation method. It was found that ...


Implicit Methods For Efficient Musculoskeletal Simulation And Optimal Control, Antonie J. Van Den Bogert, Dimitra Blana, Dieter Heinrich Dec 2013

Implicit Methods For Efficient Musculoskeletal Simulation And Optimal Control, Antonie J. Van Den Bogert, Dimitra Blana, Dieter Heinrich

Antonie J. van den Bogert

The ordinary differential equations for musculoskeletal dynamics are often numerically stiff and highly nonlinear. Consequently, simulations require small time steps, and optimal control problems are slow to solve and have poor convergence. In this paper, we present an implicit formulation of musculoskeletal dynamics, which leads to new numerical methods for simulation and optimal control, with the expectation that we can mitigate some of these problems. A first order Rosenbrock method was developed for solving forward dynamic problems using the implicit formulation. It was used to perform real-time dynamic simulation of a complex shoulder arm system with extreme dynamic stiffness. Simulations ...


Predictive Musculoskeletal Simulation Using Optimal Control: Effects Of Added Limb Mass On Energy Cost And Kinematics Of Walking And Running, Antonie J. Van Den Bogert, Maarten Hupperets, Heiko Schlarb, Berthold Krabbe Dec 2013

Predictive Musculoskeletal Simulation Using Optimal Control: Effects Of Added Limb Mass On Energy Cost And Kinematics Of Walking And Running, Antonie J. Van Den Bogert, Maarten Hupperets, Heiko Schlarb, Berthold Krabbe

Antonie J. van den Bogert

When designing sports equipment, it is often desirable to predict how certain design parameters will affect human performance. In many instances, this requires a consideration of human musculoskeletal mechanics and adaptive neuromuscular control. Current computational methods do not represent these mechanisms, and design optimization typically requires several iterations of prototyping and human testing. This paper introduces a computational method based on musculoskeletal modeling and optimal control, which has the capability to predict the effect of mechanical equipment properties on human performance. The underlying assumption is that users will adapt their neuromuscular control according to an optimality principle, which balances task ...


Predictive Simulation Of Gait At Low Gravity Reveals Skipping As The Preferred Locomotion Strategy, Marko Ackermann, Antonie J. Van Den Bogert Dec 2013

Predictive Simulation Of Gait At Low Gravity Reveals Skipping As The Preferred Locomotion Strategy, Marko Ackermann, Antonie J. Van Den Bogert

Antonie J. van den Bogert

The investigation of gait strategies at low gravity environments gained momentum recently as manned missions to the Moon and to Mars are reconsidered. Although reports by astronauts of the Apollo missions indicate alternative gait strategies might be favored on the Moon, computational simulations and experimental investigations have been almost exclusively limited to the study of either walking or running, the locomotion modes preferred under Earth's gravity. In order to investigate the gait strategies likely to be favored at low gravity a series of predictive, computational simulations of gait are performed using a physiological model of the musculoskeletal system, without ...