• Research and Development
• Underwater Navigation and Devices
• Prosthetics and Electro-Mechanical Devices
• Energy Harvesting Wireless Sensor
• Noise and Vibration Control and Optimization
• Piezoelectric and Smart Material Devices

Noise and Vibration Control and Optimization

• Testing and Analysis for On-Highway Wheel Vibration
• Wireless Video Monitoring inside Automotive Wheels
• Designing Quiet Structures through Vibro-Acoustic Optimization
• Innovative Quiet UAV Technologies (N101-039)

Testing and Analysis for On-Highway Wheel Vibration

Since the first extensive vibration study of EQUAL in 1997, a series of laboratory experiments and road tests have been performed to assess the ability of the product EQUAL to reduce tire vibration for a variety of vehicles, axle loads, and rotational speeds. The laboratory tests show that EQUAL consistently reduces the vertical (Z-direction) vibration magnitude at the fundamental frequency (1/rev). In the tests the average disturbance reduction compared to dual plane balanced wheel assemblies was 29 % in on-vehicle acceleration dynamometer testing and 55 % in fixed axle dynamometer testing. The road and test track measurements show that EQUAL consistently reduces the overall vibration magnitude in a variety of vehicles.

Wireless Video Monitoring inside Automotive Wheels

Videos were taken of the EQUAL system moving dynamically within a rotating tire. The videos have aided in understanding the mechanism by which tire vibration is reduced. Initial videos were taken with a modified wheel, and then when wireless camera technology progressed videos were taken with wireless cameras attached inside the wheel. A model describing the dynamics of the particle/tire interaction mechanism was developed to predict the vibration reduction for given operating conditions. These tests have been followed with numerous road and test track measurements.