Abstract: A tire pressure monitoring system comprising a tire pressure monitoring device for mounting on an internal surface of a tire and including a pressure sensor for monitoring the fluid pressure in the tire. The system has an RFID tag located on the tire separately from the tire pressure monitoring device. In response to detecting a tire pressure event from monitoring the fluid pressure of said fluid, the tire pressure monitoring device causes the RFID to transmit data, which is received by the tire pressure monitoring device.

Abstract: A method of determining an orientation of a tire mounted device with respect to a wheel rim using an acceleration sensor. With the wheel in a designated orientation and not rotating, a polarity of acceleration along a vertical axis is determined. Then it is determined which of a first absolute orientation or a second absolute orientation the tire mounted device is in depending on the determined polarity. The determined absolute orientation is correlated with the designated orientation to determine which of a first or second orientation with respect to the wheel rim the tire mounted device is in.

Abstract: A method of locating a wheel-mounted electronic device, such as a tire pressure monitoring device. A wireless signal is transmitted from an interrogation device from each of a plurality of interrogation locations. The signals are received by the wheel-mounted device and received signal strength is measured for each interrogation location. The wheel-mounted device then transmits, in respect of each interrogation location, a wireless signal indicating the measured signal strength. These signals are received by the interrogation device which determines from them a location of the wheel-mounted device with respect to a wheel.

Abstract: A method of determining an orientation of a tire mounted device with respect to a wheel rim using an acceleration sensor, With the wheel in a designated orientation and not rotating, a polarity of acceleration along a vertical axis is determined. Then it is determined which of a first absolute orientation or a second absolute orientation the tire mounted device is in depending on the determined polarity. The determined absolute orientation is correlated with the designated orientation to determine which of a first or second orientation with respect to the wheel rim the tire mounted device is in.

Abstract: A method of locating a wheel-mounted electronic device, such as a tire pressure monitoring device. A wireless signal is transmitted from an interrogation device from each of a plurality of interrogation locations. The signals are received by the wheel-mounted device and received signal strength is measured for each interrogation location. The wheel-mounted device then transmits, in respect of each interrogation location, a wireless signal indicating the measured signal strength. These signals are received by the interrogation device which determines from them a location of the wheel-mounted device with respect to a wheel.

Abstract: A tire monitoring apparatus comprising a monitor installed on a tire and a pulse width measuring apparatus for measuring the width of pulses produced by the monitor. The pulse width measuring apparatus comprises a frequency analyzer for producing a frequency representation of the pulse, a signal processor for determining a minimum value of the frequency representation, and a pulse width estimator that inverts the minimum value to produce a measurement for the pulse width. The tire monitoring apparatus uses the pulse width measurement as an indication of characteristics of the tire.

Abstract: A tire pressure monitoring system comprising a tire pressure monitoring device for mounting on an internal surface of a tire and including a pressure sensor for monitoring the fluid pressure in the tire. The system has an RFID tag located on the tire separately from the tire pressure monitoring device. In response to detecting a tire pressure event from monitoring the fluid pressure of said fluid, the tire pressure monitoring device causes the RFID to transmit data, which is received by the tire pressure monitoring device.

Abstract: A tyre monitoring apparatus comprising a monitor installed on a tyre and a pulse width measuring apparatus for measuring the width of pulses produced by the monitor. The pulse width measuring apparatus comprises a frequency analyzer for producing a frequency representation of the pulse, a signal processor for determining a minimum value of the frequency representation, and a pulse width estimator that inverts the minimum value to produce a measurement for the pulse width. The tyre monitoring apparatus uses the pulse width measurement as an indication of characteristics of the tyre.

Abstract: An apparatus for determining the position and/or orientation of a tire mounted unit in a wheel monitoring system comprises a lateral force sensor that is responsive to forces exerted on the respective tire along a lateral axis that is parallel with an axle of the vehicle on which the tire is mounted. The lateral force sensor is arranged to produce an output signal that indicates the direction of the exerted forces. A controller determines the position and/or orientation of the tire unit depending on the exerted force direction indicated by the output signal.

Abstract: An apparatus for determining the position and/or orientation of a tyre mounted unit in a wheel monitoring system comprises a lateral force sensor that is responsive to forces exerted on the respective tyre along a lateral axis that is parallel with an axle of the vehicle on which the tyre is mounted. The lateral force sensor is arranged to produce an output signal that indicates the direction of the exerted forces. A controller determines the position and/or orientation of the tyre unit depending on the exerted force direction indicated by the output signal.

Abstract: A tire monitor system employs a single RF detector mounted on the vehicle. The tire monitor system also includes a control unit and a receiver. The single RF detector is positioned to be proximate a front axle or a rear axle. The RF detector also may be positioned off-center. The control unit distinguishes front tire monitors from rear tire monitors by comparing a number of RF transmissions received by each tire monitor. The control unit also may distinguish between left tire monitors and right tire monitors by comparing the number of RF transmissions received by each tire monitor. In other embodiment, the tire monitor system may further use a received signal strength and/or acceleration signals to determine position information of the tire monitors.

Abstract: A remote tire monitor system includes a control unit and a plurality of tire monitors mountable on respective wheels of a vehicle to transmit radio signals to the control unit. The tire monitors each include a pair of motion sensors such as shock sensors and a control circuit configured to determine position information for the respective tire monitor based on first and second shock sensor signals from the pair of shock sensors. The shock sensors produce an output voltage proportional to a change in applied force. Therefore, the offset created by centrifugal force in previously used accelerometers is absent, simplifying design of the tire monitors.

Abstract: A tire monitor for mounting to a vehicle as part of a remote tire monitoring system includes a tire condition sensor to produce a tire condition signal, a controller coupled to the tire condition sensor to control operation of the tire monitor, and a radio circuit coupled to the controller to transmit radio signals based at least in part on the tire condition signal. A shock sensor is coupled to the controller of the tire monitor to produce a motion signal indicating motion of the tire monitor.

Abstract: An apparatus for detecting motion of a wheel comprising tyre. The apparatus comprises a pressure sensor for measuring the tyre pressure and generating a signal corresponding to the measured tyre pressure, and means for detecting a component of said signal that corresponds to, or is generated by, vibrations of the tyre. Upon detection of the signal component, the apparatus determines that the wheel is in motion. The detecting means may arranged to detect an audio signal component or signal components having a frequency in the range 200 Hz to 300 Hz.

Abstract: A tire monitor for use in conjunction with a remote tire monitoring system of a vehicle includes in one embodiment a dual-axis accelerometer and a control circuit. The control circuit determines position information such as the right/left position of the tire monitor on the vehicle in response to an acceleration signal from the dual axis accelerometer. The tire monitor transmits tire data and the position information to a control unit of a remote tire monitor system. The control unit determines additional position information such as front/rear position of the transmitting tire monitor by detecting signal strength of the transmission. This allows the system to automatically re-learn the position of tire monitors on the vehicle, even after tire rotation.

Abstract: A tire monitor system and method rely on only two RF detector mounted on the vehicle, one in close proximity to one of the front wheels and the other in close proximity to one of the rear wheels. An RF detector can distinguish between its local transmitter and the other transmitter on the same axle by the amount of signal received. Every time the controller decodes transmitted RF data, the controller looks to see if and which RF detector has detected the transmission. The controller can then determine over a short period of time which sensor identifier belongs to which corner of the vehicle.

Abstract: In a remote tire monitor system, radio frequency (RF) signals including tire data are transmitted from a plurality of tire monitors at wheels of a vehicle. At an RF receiver, the signals are received and tire data is detected. The RF signals are detected at a receiving RF detector associated with the transmitting tire monitor. The receiving RF detector produces a transmission indication in response to the received RF signals. A control unit is coupled to the RF receiver and the RF detector. The control unit receives the tire data and the transmission indication and associates a position of the transmitting tire monitor with the tire data in response to transmission indication. This permits automatic update of the position of tire monitors on the vehicle.

Abstract: In a remote tire monitor system, radio frequency (RF) signals including tire data are transmitted from a plurality of tire monitors at wheels of a vehicle. At an RF receiver, the signals are received and tire data is detected. The RF signals are detected at a receiving RF detector associated with the transmitting tire monitor. The receiving RF detector produces a transmission indication in response to the received RF signals. A control unit is coupled to the RF receiver and the RF detector. The control unit receives the tire data and the transmission indication and associates a position of the transmitting tire monitor with the tire data in response to transmission indication. This permits automatic update of the position of tire monitors on the vehicle.

Abstract: A tire monitor for use in conjunction with a remote tire monitoring system of a vehicle includes in one embodiment a dual-axis accelerometer and a control circuit. The control circuit determines position information such as the right/left position of the tire monitor on the vehicle in response to an acceleration signal from the dual axis accelerometer. The tire monitor transmits tire data and the position information to a control unit of a remote tire monitor system. The control unit determines additional position information such as front/rear position of the transmitting tire monitor by detecting signal strength of the transmission. This allows the system to automatically re-learn the position of tire monitors on the vehicle, even after tire rotation.

Abstract: In a remote tire monitor system, radio frequency (RF) signals including tire data are transmitted from a plurality of tire monitors at wheels of a vehicle. At an RF receiver, the signals are received and tire data is detected. The RF signals are detected at a receiving RF detector associated with the transmitting tire monitor. The receiving RF detector produces a transmission indication in response to the received RF signals. A control unit is coupled to the RF receiver and the RF detector. The control unit receives the tire data and the transmission indication and associates a position of the transmitting tire monitor with the tire data in response to transmission indication. This permits automatic update of the position of tire monitors on the vehicle.