Active human body models for virtual occupant response, step 3

Research Project, 2014 – 2017

Human Body Models (HBMs) are valuable tools to simulate the pre-crash and in-crash occupant response in order to develop advanced restraint systems and reconstructions of real world crashes. Also, HBMs offer possibilities to understand injury mechanisms on a detailed level and to determine injury criteria. These injury criteria are essential in assessment methods of new restraint systems. As compared to physical crash test dummies, HBM can have biofidelic sensitivity to different loading directions and differences in g-levels. HBM’s can represent different occupant sizes, gender, anthropometry and muscle tonus. HBMs are predicted to be essential tools for future virtual testing and verification.

This specific project focuses on the development of an HBM capable of tensing musculature (the SAFER A-HBM) to simulate bracing, reflexes to startle, and voluntary actions like braking and steering, which is essential to simulate occupant kinematics during emergency events, long duration crash events, and multiple events. Previous research projects have implemented muscle activity in an HBM for sagittal plane loading scenarios and applied the SAFER A-HBM to study autonomous braking combined with seat belt pretension. This project will enhance the developed methodology for sagittal plane muscle control to events with oblique and lateral loading components, including generation of volunteer data for model validation. It will also apply the enhanced SAFER A-HBM to study complex long-duration crash scenarios, like run of road and multiple crash events.

The two PhD students involved in the project will do fundamental research on how to simulate the active muscle response in a biofidelic manner. One student will focus on implementing closed loop control to simulate the active muscle response in lateral and oblique pre-crash situations, based on experimental data analyzed and published in the previous project. The other student will focus on validation data and perform an experimental study with volunteers, measuring muscle activity, kinematics and forces for oblique emergency events. The combined research of these two students is crucial in order to develop a methodology that will enhance the current SAFER A-HBM so that it can be applied to questions addressing both omnidirectional pre-crash situations as well as complex crash situations.

Beside the fundamental research by Chalmers, industrial application activities will be an important part of the project. The industrial partners will be responsible for defining the requirements for the active human body model for performance, validity range and boundaries. In addition the industrial partners will in cooperation with Chalmers be responsible for carrying out the volunteer tests. The industrial partners will apply the SAFER A-HBM in simulations to study the whole sequence of pre-crash and crash. The industrial partners will use the model at the different stages of refinement for in-house product development, with the aim to drive the developments of the model for optimal industrialization.

This project is a clear step towards development of a SAFER HBM for the extended crash sequence. Together with the other human model projects within SAFER, this project contribute to a competence platform on HBM within SAFER/Chalmers. Also, cooperation with international partners is ongoing, e.g. the Technical University of Delft, KTH, Virtual Vehicle Competence Center at K2, University of Virginia, and will be established with for example the Global Human Body Model Consortium (GHBMC) and Indian Institute of Technology in Delhi. This HBM competence platform is highly valuable for Swedish OEMs as a joint effort in establishing advanced tools for the next generation of safety system development, and the activities within this project is in the frontline research and HBM development globally. The SAFER objective within the area of human body modelling is to build edge competence that is valuable to the SAFER partners, by creating a strong network and a critical mass of researchers and PhD students. In focus are competences based on fundamental research, focusing on applied aspects with complex kinematics (including low-g and high-g, combination of various directions) and various human properties.