Magnetorheological Active Damper with Linear Resonating Actuator (MAD-LRA) and Magnetorheological Impact Foams (MIF) for Mitigation of Helmet Vibratio

Noisy cockpits lead to higher workload during flight, compromised radio communications and excessive fatigue in pilots post flight. Excessive noise in cockpit also results in a temporary shift of the auditory threshold known as a Temporary Threshold Shift(TTS). At low frequencies, the helmet itself starts resonating at the characteristic frequency of the helmet close to the excitation source frequency such as BPF. This causes the ear cups to break seal with the pilots head and subject the pilot to excessive noise. The existing Communications earplug and active noise reduction technology cannot eliminate the helmet vibration. Therefore there is a need for new a technology reduce resonating helmet noise. We propose to develop a Magnetorheological Active Damper with Linear Resonating Actuator(MAD-LRA) and Magnetorheological Impact Foams(MIF) for mitigation of helmet vibration. There are two key innovations; one, is to integrate magnetorheological damping along with existing Linear Resonance Actuator(LRA) to develop an active damper with tunable damping force and frequency; two, to use state-of-the-art Magnetorheological Impact Foam(MIF) pads for passive damping using magnetic sheets creating light weight MIF damping pads for effective passive damping at selected locations. Combination of these active and passive damping will provide effective mitigation of helmet vibration during flight.