Ford Motor Company Limited

University of Michigan

John Wang

Edwin B Olson

Prakash Tuljaram Thawani

Mukesh Kumar

Hemant Sumentlal Shah

Richard Charles Kosik

John Stuart Hollingshead

A method for determining the rotational rate of a movable member using an array of inertial sensors is provided. The method includes defining a hidden Markov model ('HMM'). The HMM represents a discrete value measurement of the rotational rate of the movable member. A transition probability of the HMM accounts for a motion model (linear or non-linear) of the movable member. An observation probability of the HMM accounts for noise and bias of at least one of the inertial sensors of the array of inertial sensors. A processor receives input from the array of inertial sensors. The processor determines the rotational rate of the movable member by solving for an output of the HMM using the input received from the array of inertial sensors. The processor may use a forward algorithm, a forward-backward algorithm, or a Viterbi algorithm to solve the HMM.

High-performance inertial measurements using a redundant array of inexpensive inertial sensors

The present invention is a system and method to significantly reduce noise associated with air-moving devices such as an axial flow fan using a fan shroud and barrel combination with built in silencers such as Helmholtz resonators. The invention can be applied to a variety of applications such as a thermal management system for a fuel cell powered vehicle. The resonator can be a hollow cavity in networks attached to an outer or inner barrel or shroud and tuned to reduce noise at predetermined noise frequency ranges within the airflow. The invention can also attach stator members on the inner surface of the outer barrel to further reduce noise. Additional sound absorbing material, such as steel wool, can be disposed within the resonator cavity.

Fan shroud with built in noise reduction

Growing community of inventors

Ann Arbor, MI, United States of America

John Wang