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.

A system includes an acceleration sensor for detecting a centrifugal acceleration, and a processing unit, which is coupled to the acceleration sensor and which is configured to determine numerical values from measured values of the centrifugal acceleration. The determined numerical values are representative of a mileage of a tire and/or wear of the tire and/or an installation radius of the system in the tire.

In a method for determining identifiers of wheel units and positions relative to the vehicle of the wheels on which the wheel units are fitted, the vehicle is equipped with a speed sensor for each wheel and elements for transmitting at a predetermined angular position of the corresponding wheel about its axis a message including the identifier of the wheel unit. A central processing unit receives the message and information from the speed sensors. The method includes a) counting, for each identifier, of a number nt of receptions of the identifier, b) statistical processing of the numbers nt to determine candidate identifiers of a wheel unit of the vehicle, until the number of candidate identifiers at least equals the number of wheels, and c) determining that a candidate identifier is the identifier of a wheel unit if the candidate identifier meets a predetermined criterion.

A vehicle wheel information acquiring device includes a vehicle wheel sensor and a vehicle-body-side device. The vehicle wheel sensor is configured to revolve around an axle with a rotation of a vehicle wheel. The vehicle-body-side device includes a reception unit, a processing unit, a rotation position acquiring unit, an on-reception rotation position storage unit, and a determination unit. The determination unit is configured to determine whether a revolution position of the vehicle wheel sensor is included in an insufficient received intensity area during a stopping operation of a vehicle.

A wheel position detector for a vehicle includes: a transmitter at each wheel having a first control portion for transmitting a frame with specific identification information; and a receiver at a vehicle body receiving the frame from one wheel and having a second control portion for performing wheel position detection; and a wheel speed sensor for detecting a tooth of a gear. The second control portion: acquires gear information indicating a tooth position; sets a variation allowance based on the tooth position; registers the one wheel with using the variation allowance; and performs the wheel position detection by excluding an identified wheel as the one wheel from a candidate of another wheel mounting the transmitter that transmits another frame when the second control portion identifies the one wheel.

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.

Embodiments relates to systems and methods to calculate a tire pressure scheme to be utilized by a tire of a vehicle during a trip, communicate a command to the tire pressure control apparatus, to adjust tire pressure of a tire based on the tire pressure scheme, detect a problem encountered in adjusting the tire pressure of the tire based on the tire pressure scheme, generate an alert regarding the problem via a driver assistance interface, and recommend an action to be taken to mitigate the problem.

Embodiments relates to systems and methods to calculate a tire pressure scheme to be utilized by a tire of a vehicle during a trip, communicate a command to the tire pressure control apparatus, to adjust tire pressure of a tire based on the tire pressure scheme, detect a problem encountered in adjusting the tire pressure of the tire based on the tire pressure scheme, generate an alert regarding the problem via a driver assistance interface, and recommend an action to be taken to mitigate the problem.

The present invention provides an Active Tire Auto-Location systems for tire pressure monitor sensors and an operating method. The system includes a host, wheel axle rotation detection devices and tire pressure monitor sensors. By allowing the wireless tire pressure detector to receive and compare the rotation information of a toothed ring from the wheel axle rotation detection device and the tire rotation information from the wireless tire pressure detector, each wireless tire pressure detector can identify which wheel axle rotation detection device that corresponds to it. At the same time, the tire position where each wireless tire pressure detector is situated can also be determined. Compared to prior art, it is still possible for the present invention to determine the tire position where each wireless tire pressure detector is situated, without the need for additional modification to the host, thus significantly reducing the inconvenience in replacing tire pressure monitor sensors.

A method of determining a left or right side installation position of a trailer wheel of a trailer connected to a tow vehicle. A number of rotations of the trailer wheel is determined. A number of rotations of a left side tow vehicle wheel and a right side tow vehicle wheel is determined. A first correspondence value between the number of rotations of the trailer wheel and the number of rotations of the left side tow vehicle wheel is determined. A second correspondence value between the number of rotations of the trailer wheel and the number of rotations of the right side tow vehicle wheel is determined. A left side or right side installation position of the trailer wheel is determined based on the first correspondence value and the second correspondence value.