A reception control section obtains a rotation angle of each wheel assembly when a reception circuit receives transmission data. The reception control section calculates the absolute value of the difference between the obtained rotation angle and a previously obtained rotation angle. The reception control section determines whether the absolute value of the difference is included in a reference range or a specific range. The reference range includes 0. The specific range includes the angle difference between specific angles.

Techniques are described for using one or more wireless host devices to perform tire localization of TPMS sensor data by determining received signal strength indicator (RSSI) signatures that are unique to the wireless communication channel between a host device and each TPMS sensor. RSSI signatures represents a periodic variation of the wireless communication channel between a host device on the car body and a TPMS sensor in a rotating tire. Characteristics of the communication channel is a function of the wheel angle and is periodic with wheel rotations. The RSSI signatures may be created by matching RSSI measurements of packets received by the host device from a TPMS sensor with wheel angles derived from wheel speed sensor (WSS) data of the anti-lock braking system (ABS). The RSSI signatures are a unique marker of each wheel that may be used to identify the locations of the TPMS sensors for tire localization.

The tire state detecting device includes a calculating unit that calculates an acceleration difference of the gravitational acceleration value acquired at a first acquiring angle and the gravitational acceleration value acquired at a second acquiring angle; a storage unit that stores a correction formula defined in advance based on an angular difference between the adjacent acquiring angles and an angular difference of the first acquiring angle and the second acquiring angle, and corrects the first acquiring angle to an angle determined in advance from the acceleration difference; a transmission unit that transmits a transmission signal including information indicating the angle determined in advance in addition to information indicating the state of the tire; and a control unit that causes the transmission signal to be transmitted to a wheel position specifying device.

An aspect of the invention relates to a method for the radio-oriented optimization of wheel monitoring in a vehicle equipped with vehicle wheels, wherein the monitoring of at least one of the vehicle wheels is prompted by an electronic wheel unit arranged on the relevant vehicle wheel capturing at least one wheel operating parameter of the vehicle wheel, and radio signals containing information about the at least one captured wheel operating parameter being transmitted for a respective wheel rotational position of the vehicle wheel, stipulated by the electronic wheel unit, wherein the radio signals are received and evaluated by a control device of the vehicle and wherein the radio-oriented optimization of the wheel monitoring is prompted by the electronic wheel unit being used to transmit multiple radio signals for different wheel rotational positions, wherein the radio signals are received by means of the control device and rated in respect of their respective radio signal strength, wherein the control device is used to transmit an optimization radio signal to the electronic wheel unit, wherein the optimization radio signal contains optimization information formed on the basis of the rating of the radio signals, and wherein the electronic wheel unit is used to receive the optimization radio signal, and the optimization information contained therein is taken into consideration for the stipulation of the wheel rotational position of the vehicle wheel for radio signals that are to be transmitted subsequently.

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.

Determining installation positions of tires can include: measuring, by a magnetic sensor provided in each tire in the same manner, a first magnetic field strength in a first direction and a second magnetic field strength in a second direction, where the first direction is a circumferential or axial direction of the tire and the second direction is a radial direction of the tire; acquiring a first magnetic field strength sampling value of the tire by sampling the first magnetic field strength; acquiring a second magnetic field strength sampling value of the tire by sampling the second magnetic field strength; calculating a difference between the first and second magnetic field strength sampling values; and determining whether the installation position of the tire is on the left or right side of a vehicle according to a change trend of the calculated difference of the tire.

Method for locating the position of the wheels of a vehicle, each equipped with an electronic module for measuring operational parameters of each wheel, includes: controlling the transmission, by the module equipping that wheel, of n signals transmitted at times t.sub.1 to t.sub.n for given angular positions .sub.1 to .sub.n of the module, to a connected central processing unit, and to speed sensors each positioned close to a wheel, capable of delivering, values convertible into angular values, data representing the orientation of the wheel. The central processing unit is programmed to calculate, for each series of angular values .sub.1 to .sub.n provided by a wheel measuring sensor at the times t.sub.1 to t.sub.n, a characteristic value V.sub.n1-V.sub.nr representing the dispersion of the values .sub.1, (.sub.2.sub.2) . . . (.sub.n.sub.n), and to compare the characteristic values to allocate, to the electronic module, the position of the wheel located close to the wheel speed sensor.

A vehicle tire monitoring system has an electronic controller in electronic communication with a rotation sensor, an input device and a signaling device. The electronic controller is configured to do at least the following. In response to the input device receiving a request to orient a valve stem of a tire with low air pressure to a predetermined orientation, the electronic controller determines that the valve stem is not currently in the predetermined orientation. The electronic controller operates the signaling device to provide a first signal to a vehicle passenger and/or the vehicle operator. Further, in response to receiving the request to orient the valve stem to the predetermined orientation and determining that the valve stem is currently in the predetermined orientation, the electronic controller operates the signaling device to provide a second signal indicating the need to rotate the tire to bring the valve stem to the predetermined orientation.

A sensor transmitter calculates a tilt angle for attachment of a G sensor to a corresponding one of wheels and estimates whether the sensor transmitter itself is attached to a right wheel or a left wheel based on a calculation quadratic function, a calculation linear function, a measurement quadratic function, and a measurement linear function. Then, a receiver determines whether the sensor transmitter is attached to a front wheel or a rear wheel based on the result of the estimation and an effective tire radius. In this manner, it can be determined which one of the wheels the sensor transmitter is attached to.

A tire pressure monitoring device can include: a magnetic sensor configured to measure a first magnetic field intensity in a first direction, and to measure second magnetic field intensity in a second direction; and a controller configured to control a state of the tire pressure monitoring device based on a variation of the first magnetic field intensity and a variation of the second magnetic field intensity.