Digital Human Modeling and Simulation for Biomechanical Analysis
10:00 am, March 17, 2008 in RHFH 557
Abstract
Digital human modeling and simulation plays an important role in product design, prototyping, manufacturing, and biomechanical study. Data-driven models are widely used in engineering and biomechanical applications. However, the attention in this presentation is focused on the optimization-based human model developed by the author.
The optimization-based human model is a new generation of digital human models that are highly realistic in terms of appearance, movement, and feedback (evaluation of the human body during task execution). It includes the following capabilities: an anatomically accurate human model with high degrees of freedom, posture prediction, predictive dynamics, musculoskeletal modeling (muscle wrapping, muscle force determination, and muscle stress analysis), and hand biomechanics. Posture prediction includes multiple end-effectors (two arms, two arms + head + legs). This approach allows the avatar to operate with complete autonomy rather than with dependence on stored animations and data or restrictions associated with inverse kinematics. Traditionally, there are forward and inverse dynamics. In forward dynamics, we try to find the kinematic properties given the external forces; in inverse dynamics, we try to find the external forces given the motion. However, in predictive dynamics, we predict the motion without being given the complete set of external forces and motion. Furthermore, with predictive dynamics, it is not necessary to directly integrate equations of motion. Based on the optimization-based formulation, we can predict all different kinds of motions, such as walking, running, stair-climbing, throwing, and box-lifting. After obtaining joint torques in predictive dynamics, we can determine the muscle forces and analyze muscle stresses. Furthermore, we can obtain joint reaction forces to launch joint/bone finite element analysis and predict injuries.
About the speaker
Dr. Jingzhou Yang is currently a Research Engineer with the Center for Computer Aided Design (CCAD), and Adjunct Assistant Professor at the Department of Mechanical and Industrial Engineering, the University of Iowa, Iowa City, USA. He received his BS and MS degrees in Automotive Engineering from Jilin University, China and a Ph.D. degree in Mechanical Engineering from the University of Iowa. He was a faculty member at the Department of Automobile Engineering and a researcher at the State Key Laboratory of Automotive Safety and Energy Conservation, Tsinghua University, Beijing, China. He is a recipient of the Arch T. Colwell Merit Award from the Society of Automotive Engineers (SAE) in 2003, the 2004 Outstanding Paper Award from ASME, and the 2007 The Prometheus Award (Top U.S. Government Technology Award). Dr. Yang is Executive Editor for International Journal of Human Factors Modelling and Simulation, Associate Editor for International Journal of Robotics and Automation, Guest Editors for special issues of International Journal of Vehicle Design and International Journal of Vehicle Autonomous Systems. His research interests include digital human modeling and simulation, computational biomechanics, bioengineering modeling, and ergonomics.
