A tire parameter monitoring apparatus, method, and system are provided. The apparatus includes a receiver, a processor, and an output circuit. The receiver may be configured to receive an excitation signal. The processor may be configured to determine an output parameter, such as a frequency, a phase, or an amplitude, of a reflected output signal based on a monitoring parameter of a tire, where resonance frequency information of the tire is related to the monitoring parameter of the tire, and the output parameter of the output signal is related to the resonance frequency information of the tire. Passive tire pressure monitoring can be performed, so that production and use costs of the tire pressure monitoring system can be reduced, and reliability can be improved.

A radio frequency identification (RFID) tag includes an antenna, an analog front end, a processing circuit, and memory. The analog front end includes a power circuit, a tuning circuit, a transmitter, and a receiver. The power circuit is operably coupled to convert a radio frequency (RF) signal into a power supply voltage. The tuning circuit, when enabled, adjusts an RF characteristic of the analog front end to tune power harvesting from the RF signal. The transmitter is operably coupled to transmit a response signal to the RFID reader via the antenna. The receiver is operably coupled to receive a command signal from the RFID reader, wherein the command signal is contained within a portion of the RF signal. The processing circuit is operable to interpret the command signal and generate the response signal.

The present invention is related, but is not restricted, to the field of the study or analysis of materials by determining the chemical or physical properties thereof, in particular the field of the investigation or analysis of materials by using electromagnetic waves, specifically providing a method from measuring internal stress in tires, using a ferromagnetic material.

The invention provides a method for measuring internal stress in a tire, characterized in that it comprises: incorporating into the tire a material that is a combination of a rubber matrix and a plurality of microwires made of a ferromagnetic material; irradiating said tire with electromagnetic waves by means of a transmitting antenna; receiving an electromagnetic wave absorption response from said tire by means of a receiving antenna; and determining the internal stress of the tire by means of a processor operatively connected to said receiving antenna, on the basis of the electromagnetic wave absorption response. The invention further provides a material for measuring the internal stress in a tire, characterized in that it is a combination of a rubber matrix and a plurality of microwires made of a ferromagnetic material.

A tire management system is provided for automatically inflating and deflating tires of a vehicle. The system comprises: couplings, for releasably coupling to each of the tires of the vehicle; an inlet, for receiving compressed gas, the inlet selectively couplable to the couplings for inflating the tires of the vehicle; an outlet, selectively couplable to the couplings for deflating the tires of the vehicle; and a controller, configured to receive a desired target pressure for one or more of the tires and automatically couple the inlet or outlet to the one or more tires to achieve the target pressure. The tires are grouped into two or more groups of tires, and wherein the controller is configurable to inflate and/or deflate the tires according to the groups of tires.

A patch-type passive acoustic waving sensing device includes a surface acoustic wave sensor and at least a first and second rubber sheets. A cross-section of each of the first and second rubber sheets is larger than that of the surface acoustic wave sensor. A bottom of the surface acoustic wave sensor is on an upper surface of the first rubber sheet, and a first central hole allowing the surface acoustic wave sensor to penetrate therethrough is formed in a center of the second rubber sheet. The surface acoustic wave sensor penetrates the first central hole, and the second rubber sheet is fixedly connected to the upper surface of the first rubber sheet. The surface acoustic wave sensor includes pins at the bottom thereof such that free ends of the pins are connected to an antenna, and the antenna and some of the pins are inside the first rubber sheet.

A tire pressure monitoring system (TPMS) sensor module as provided herein includes a pressure sensor configured to measure an internal air pressure of a tire and generate tire pressure information; a transducer configured to receive a structure borne sound signal induced by sound waves; a receiver circuit electrically connected to the transducer and configured to detect the structure borne sound signal and generate a detection indication that the structure borne sound signal has been detected; a processing circuit electrically connected to the pressure sensor and the receiver circuit, and configured to receive the tire pressure information from the pressure sensor, receive the detection indication from the receiver circuit, and generate a communication signal in response to receiving the detection indication; and a transmitter electrically connected to the processing circuit and configured to transmit the communication signal.

A system for estimating a tire load of a tire includes a pressure sensor configured to generate a tire pressure signal; an acceleration sensor configured to generate a tire acceleration signal; a temperature sensor configured to generate a tire temperature signal; and at least one processor configured to calculate a duration of a contact patch based on the tire acceleration signal, calculate a vehicle speed based on the tire acceleration signal, determine at least one system model coefficient based on the tire pressure signal and the tire temperature signal, and calculate the tire load of the tire using a linear system model that relates tire pressure, the duration of the contact patch, and the vehicle speed to the tire load of the tire, where the linear system model further includes the at least one system model coefficient for calculating the tire load of the tire.

A surface elastic wave resonator comprises a piezoelectric material to propagate the surface elastic waves and a transducer inserted between a pair of reflectors comprising combs of interdigitated electrodes and having a number Nc of electrodes connected to a hot spot and an acoustic aperture W wherein the relative permittivity of the piezoelectric material is greater than about 15, a product of Nc.Math.W/fa for the transducer being greater than 100 m.Math.MHz.sup.1, where fa is the antiresonance frequency of the resonator. A circuit comprises a load impedance and a resonator according to the invention and having an electrical response manifesting as a peak in the coefficient of reflection S.sub.11 at a frequency of a minimum value of the parameter S.sub.11 that is lower than 10 dB, the antiresonance peak of the resonator being matched to the impedance of the load.

A system for estimating a tire load of a tire includes a pressure sensor configured to generate a tire pressure signal; an acceleration sensor configured to generate a tire acceleration signal; a temperature sensor configured to generate a tire temperature signal; and at least one processor configured to calculate a duration of a contact patch based on the tire acceleration signal, calculate a vehicle speed based on the tire acceleration signal, determine at least one system model coefficient based on the tire pressure signal and the tire temperature signal, and calculate the tire load of the tire using a linear system model that relates tire pressure, the duration of the contact patch, and the vehicle speed to the tire load of the tire, where the linear system model further includes the at least one system model coefficient for calculating the tire load of the tire.

A tire pressure monitoring system (TPMS) sensor module as provided herein includes a pressure sensor configured to measure an internal air pressure of a tire and generate tire pressure information; a transducer configured to receive a structure borne sound signal induced by sound waves; a receiver circuit electrically connected to the transducer and configured to detect the structure borne sound signal and generate a detection indication that the structure borne sound signal has been detected; a processing circuit electrically connected to the pressure sensor and the receiver circuit, and configured to receive the tire pressure information from the pressure sensor, receive the detection indication from the receiver circuit, and generate a communication signal in response to receiving the detection indication; and a transmitter electrically connected to the processing circuit and configured to transmit the communication signal.