Ruprecht-Karls-Universität Heidelberg
Optimization in Robotics and Biomechanics

Stability and robustness of human motion

Khai-Long Ho HoangKatja Mombaur - IWR

Sebastian Wolf - Orthopedic University Hospital Schlierbach, Heidelberg University


Human locomotion on two legs is characterized by its high versatility. Individuals perform everyday tasks such as running on an even racetrack, jumping over gaps, climbing rough ground on a mountain, or strolling around in a museum given the ability to instantly switch between locomotion modes adapted to very diverse circumstances.

Human locomotion requires high-level dynamic coordination and stability control enabling it to work quite robustly even in very uneven and changing environment. 

The execution of different locomotive tasks is possible even with disturbances in the locomotor system, e.g. in patients walking with prosthetic devices. Nevertheless, walking with prostheses can be extremely challenging when it comes to descending slopes, ascending stairs or walking on uneven ground.

Unfortunately, the amazing stability control capabilities of humans (and of animals alike) are not yet fully understood. This becomes obvious in the field of humanoid robots which in recent years have been taught a variety of different motions, but which still lack far behind their human counterparts in terms of speed, elegance and efficiency. The aim of our research is to gain a fundamental understanding of the underlying principles human movement, and in particular of walking - in healthy subjects as well as patients with prostheses - by using scientific computing techniques.

We investigate human locomotion using a multi-body system model of the human body, which includes the rigid multi-body dynamics and compliant elements as well as models of major muscles and relevant feedback loops. Experiments cover stable and unstable motions in various situations for different subjects representing healthy walking and unilateral amputees. Optimal control is used to determine the controls that lead to the best fit between model and experiments. Stability criteria related to angular momentum, capture point and Lyapunov stability are investigated for these gaits.

 

K. Mombaur, orb@uni-hd.de
Last Update: 19.10.2011 - 16:03

The photographs in the header of this webpage have been taken at the Musee de l'Automate in Souillac, France