A tire pressure monitor sensor is disclosed. The sensor includes a wireless transmitter and a processing unit. The processing unit provides a time trigger signal within a measurement period and triggers a wireless transmission of a reference signal indicating an occurrence of the time trigger signal to a remote unit. The tire pressure monitor sensor is configured to derive, based on a plurality of acceleration measurement samples within the measurement period, information indicting at least one rotation property of a tire. The tire pressure monitor sensor is further configured to wirelessly transmit the derived information to a remote unit separate from the reference signal.

It should be enabled to transmit tire-pressure information also on a spare wheel to a tire-pressure notification device, while suppressing battery consumption. A transmission controller of a sensor unit makes a transmitter periodically transmit wheel information, when an acceleration Gx detected by an acceleration sensor is larger than a running-judgment threshold value 5G. The transmission controller accumulates a point P set up according to the acceleration Gx in a predetermined period when the acceleration Gx is not more than the running-judgment threshold value 5G, and makes the transmitter transmit the wheel information when an accumulated value of the point P accumulated in the predetermined period is larger than a running-track-record-judgment threshold value.

The present invention relates to the system for measuring the slip of a tyre (10) with respect to a rim (20), on which said tyre (10) is mounted. In particular, said system comprises a first electronic device (1) and a second electronic device (2), each of which is configured at least to acquire, filter, store and send data, and a processing unit (3), external to said electronic devices (1, 2), configured at least to receive and process the data sent by each electronic device (1, 2), in order to measure said slip by measuring an angle (?) and comparing the value of this angle with respect to at a reference angle ?.sub.ref. The present invention also relates to method for measuring the slip of a tyre (10) with respect to a rim (20), on which said tyre (10) is mounted.

A wheel position detection apparatus is applicable to a vehicle in which four wheels provided with tires are attached to a vehicle body, and is provided with sensor transmitters and a receiver. The sensor transmitters each include an acceleration sensor and a first control portion that detects the position of the corresponding wheel on the basis of the acceleration thereof, and creates and transmits a frame in which data indicating the result of the wheel position detection are stored. The receiver is provided in the vehicle body, and includes: a receiving portion that receives each transmitted frame by means of a receiving antenna; and a second control portion that identifies whether the sensor transmitter that has transmitted each frame is attached to the right wheels or the left wheels, from among the four wheels.

A method of measuring and transmitting a tire characteristic using a sensor device mounted to a tire of a wheel, the sensor device comprising a sensor element, an accelerometer, a wireless transmitter, and a microprocessor; the method comprising the steps of: a) obtaining acceleration data; b) digitally filtering the acceleration data; c) determining moments in time when the wheel is in an angular position range; d) obtaining other sensor data; e) transmitting the other sensor data at said moments in time, step b) comprising using exponential moving average filters connected in series, corresponding to a predefined set of formulas comprising parameters, and f) determining number of samples per 360 rotation, and setting the parameters to a value proportional to said number of samples. A sensor device adapted for performing said method.

A method for localizing the installation position of wheels in a motor vehicle having at least a first, second and third wheels, includes allocating respective wheel electronics to the wheels for emitting a radio signal with an identifier and allocating at least one vehicle-side rotational angle sensor to at least a first possible installation position. The installation position of the first wheel is determined by output signals of the rotational angle sensor at a first possible installation position. In addition, the installation position of the second and third wheels is determined by measuring the field strength of radio signals with identifiers of the wheel electronics of the second and third wheels by using a vehicle-side receiving device. In this way, precise determination of the location of the wheel electronics can be performed with minimum expenditure on devices, without having to provide a rotational angle sensor on each wheel.

Systems and methods of determining tire load from measured tire parameters include using a piezoelectric based sensor to obtain one or more contact patch parameters (e.g., contact patch entry time, contact patch exit time total contact patch time and contact patch angle) and one or more additional sensors to obtain tire pressure. Selected contact patch parameter measurements and pressure values are then compared with known combinations of contact patch parameter values and pressure values stored in a look-up table. A corresponding determined tire load value is then provided as electronic output.

A sensor module is provided that includes a magnetic sensor and a microcontroller. The magnetic sensor is configured to measure a magnitude of a magnetic field component of an Earth magnetic field projected on a sensing axis of the magnetic sensor and is configured to generate a measurement signal. The magnetic sensor is configured to rotate about an axis through the Earth magnetic field such that the measurement signal oscillates between a first and second extremas as the magnitude of the magnetic field component projected onto the sensing axis changes due to rotation of the magnetic sensor about the axis. The microcontroller is configured to receive the measurement signal, acquire a predetermined number of measurement samples over a sampling period, calculate a variance value of the acquired measurement samples, and determine whether the magnetic sensor is rotating about the axis based on a threshold test of the variance value.

An intelligent tire pressure monitoring system and method are provided in present disclosure. The system includes a CAN bus module, a diagnosing module, a processor, a 3G module, a GPS module and a server. The CAN bus module and the diagnosing module detect rotational speed of each tire and steering angle of steering wheel, and send a detecting result data the processor. The GPS module obtains position information of the automobile, and sends it to the processor. The processor calculates and processes the detecting result data and the position information of the automobile, and uploads them to the server through the 3G module. The server calculates a pressuring value of each tire according to the detecting result data, the position information of the automobile, weather conditions of continuous several days, and condition of road traveled by the automobile, and do appropriate treatment.

A wheel position detection device includes: a transmitter in each wheel of a vehicle having a first control unit for transmitting a frame with ID and an acceleration sensor; and a receiver on a vehicle body, including a second control unit for registering the ID in association with the wheel. The first control unit detects a wheel speed, and stores data of the acceleration sensor in the frame. The second control unit includes: a first determination device that determines a condition that the acceleration sensor is not in an on-state; a candidate registration device that registers a candidate of the ID of a spare wheel when the condition is satisfied; a second determination device that determines a travel history of the vehicle; and a registration device that identifies the ID of the spare wheel when the travel history is present, and registers the ID in association with the spare wheel.