Real-time wireless dynamic tire pressure sensor and energy harvesting system

Abstract

An instantaneous / real-time wireless dynamic tire pressure sensor (DTPS) for characterizing pavement qualities and for detecting surface and subsurface pavement defects under normal driving conditions. Signal processing provides quantitative assessment of surface conditions. DTPS includes a vehicle tire valve stem-mounted pressure sensor and wheel hub-mounted signal conditioning, amplification, and transmitting circuitry. A signal processing computer within the vehicle is wirelessly coupled to the hub-mounted circuitry. Tire pressure changes caused by ground vibration excitation from the interaction between the tire and pavement at normal driving speeds are detected. When acoustic radiation from a surface wave is significantly stronger than acoustic noise, subsurface information can be extracted. An energy harvester based on strong magnetostatic coupling between a high permeability core solenoid, fixed proximate a vehicle wheel, and a bias magnet array, fixedly mounted in conjunction with a dust shield, can provide power the DIPS.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and is a continuation of International Application No. PCT / US2012 / 038842 filed May 21, 2012, entitled “REAL-TIME WIRELESS DYNAMIC TIRE PRESSURE SENSOR AND ENERGY HARVESTING SYSTEM,” which claims the priority of U.S. Provisional Application No. 61 / 488,399 filed May 20, 2011, entitled “REAL-TIME WIRELESS DYNAMIC TIRE PRESSURE SENSOR (DTPS),” and U.S. Provisional Patent Application No. 61 / 488,407 filed May 20, 2011, entitled “WIRELESS ENERGY HARVESTING SYSTEM FOR REAL-TIME PRESSURE MONITORING SYSTEM.” The aforementioned related applications are hereby incorporated by reference in their entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]The research leading to this invention was carried out with U.S. Government support provided under a grant from the National Institute of Standards and Technology (NIST) Technology Innovation Program (TIP), Grant No. 70NANB9H9012. The U.S. Governme...

AI Technical Summary

Benefits of technology

The patent describes a non-destructive and non-contact acoustic sensing technique for inspecting road and bridge deck conditions with vehicles running at normal speed without delaying or stopping other traffic. The technique uses a real-time dynamic tire pressure sensor (DIPS) placed inside the tire to measure dynamic pressure change inside the tire. The DIPS is able to isolate and amplify ground motion from environmental noise and detect surface and subsurface conditions. The disclosed approach provides advantages such as enabling non-destructive testing, requiring no periodic striking contact, and being able to travel at high speeds. The data analysis algorithm enhances detection accuracy, and the unique features of the DTPS include the tire as a natural barrier, direct contact with the ground, protection of the instruments, and mapping of roadway condition information with precision. The DIPS data is preferably time-stamped for accurate positioning information. The patent also describes a rotating energy harvester that can power electronic sensors and wireless sensor networks, which can be used to power the DIPS. The energy harvester design has been fabricated and tested, and results show that it can generate constant and steady power sufficient for continuous operation of the TPMS. The technical effects of the patent include improved efficiency and accuracy in inspecting road and bridge deck conditions with vehicles running at normal speed.

Problems solved by technology

Aside from the obvious risk of transducer impact with the ground, there is a risk that the ambient noise would prevent the detection of acoustic signals from the tire-road interface and surface waves that propagate in the road.

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