A tire air pressure detection device has transmitters each detecting a running state of a vehicle on the basis of a detection signal of an acceleration sensor and transmitting a frame when it is determined that the vehicle is running. Because acceleration varies independently of a tire rotation speed, a frame can be transmitted even before a vehicle speed reaches or exceeds, for example, 30 km/h. Consequently, data on a tire air pressure can be transmitted in a short time period from a running start of the vehicle and hence a decrease in tire air pressure can be detected in a short time period from the running start of the vehicle.

An apparatus for determining a driving situation of a vehicle to be monitored is disclosed. The apparatus comprises a provider configured to provide measurement values, wherein the provider is configured to obtain the measurement values at non-equidistant sampling instants, wherein the measurement values comprise information relating to the driving situation of the vehicle to be monitored. The apparatus further comprises an evaluator configured to evaluate a plurality of the measurement values with respect to a measure indicating a temporal variation of the plurality of measurement values.

A tire pressure sensor device (122) for a wheel (112) of an aircraft (102) including a pressure sensor (124) for measuring the internal pressure of a tire, a temperature sensor (126) for measuring a temperature local to the tire (116), a memory unit (131) local to the tire for storing data, and a control unit (128) local to the tire arranged to record in the memory unit (131) data of the readings taken at intervals of time. The data recorded for each reading includes an indication of the time of the reading, the tire pressure and the temperature local to the tire. Measurements may be taken and recorded over time, both when the aircraft is on the ground and when the aircraft is in flight. Data may be uploaded to a portable handheld device (140) for analysis when maintaining the tires in their correctly inflated state.

Method for transmitting a radio signal between a moving electronics unit of a wheel and a fixed central electronic control unit of the vehicle, includes: defining an angular reference point of the wheel; defining a division of one wheel revolution into successive basic sectors, and transmitting successive radio signals between the two units so that each signal is transmitted at a calculated predetermined wheel angular position; calculating the angular rotation speed of the wheel; determining a minimum wheel rotation sector required for the transmission time of a signal between the two units, at the calculated angular rotation speed; determining an angular offset of transmission between a first and a second following signal, with respect to the angular reference point, as being equal to the smallest multiple of the basic division sector which covers the time required for transmission of the first radio signal at the calculated angular rotation speed.

Methods and apparatus for determining whether a vehicle tyre pressure check has been carried out, comprising: receiving from a pressure reader module a request for tyre pressure data indicative of a the pressure of a gas retained within a pneumatic tyre; storing, by a pressure check register, data indicating that the request for tyre pressure data was received; transmitting, by a transmitter to an apparatus, an indication confirming whether a tyre pressure check has been carried out based on whether the request for tyre pressure data was received; receiving, at the apparatus from a plurality of tyre pressure sensing modules, a plurality of indications of whether a tyre pressure reader has been used on each of the plurality of tyre pressure sensing modules to check a corresponding tyre pressure; and determining, by a pressure check confirmer, whether a vehicle tyre pressure check has been carried out based on the received plurality of indications.