Automotive manufacturers at the SAE World Congress this week rolled out new technologies that could help crash dummies provide better information to researchers.
Boxboro Systems, for example, showed off an optical non-contact measurement system that combines LEDs and optical sensors to simulate deflection of a driver’s chest during a crash. Employing the technology in a product known as the RibEye ATD Thorax Displacement Technology system from Robert A. Denton, Inc., engineers showed how optical sensors can be used to track movement of the LEDs. By “watching” the LEDs, which are mounted on each rib in an artificial ribcage, two light angle sensors on the unit’s spine can measure movement. The system employs a triangulation technique to calculate the exact amount of deflection in three axes. The new technique replaces simple, linear potentiometers, which measure the deflection of chests in only a single axis.
“Our method shows how the thorax compresses in the x-, y-, and z-axes and allows engineers to build better dummies,” said Daniel Handman, president of Boxboro Systems. “Linear potentiometers worked well, but only if you had compression straight into the chest.”
Boxboro’s method measures the position of the LEDs in three axes 10,000 times per second, thus enabling the system to accurately detect chest forces during the huge accelerations associated with crash tests.
Denton engineers also showed a separate system aimed at simulating forces around the human head and neck. Known as the Focus (Facial and Ocular Countermeasure for Safety Headform) head, it provides a test platform for eye and facial injury studies. The mechanical head incorporates facial sensors, load-cells for non-penetrating injuries, and synthetic eyes. Sensors in the head enable engineers to study five different facial bones and eight discrete facial bone segments. Denton engineers say that it could be employed for studies of motorcycle-related injuries and sports injuries, as well as facial effects from air bag impacts.
“It can help (researchers) better understand air bag loads on the forehead, chin, and to the eyes,” said Craig Morgan, vice president of research and development for Denton.
Suppliers at the show also rolled out crash dummy sensors. Measurement Specialties, for example, demonstrated new tri-axial MEMS-based accelerometers. The company also showed accelerometers in mini-packages that mount directly inside the dummy, thus enabling crash test engineers to replace only the sensor, instead of the entire accelerometer, when a change is needed.
“The big trend in dummies is away from large electronic packages,” said Bob Arkell, product manager for Measurement Specialties. “Manufacturers want just the sensor, not the entire electronic package, to be placed directly inside the dummy.”