A tire pressure decreased detection apparatus comprising rotation speed information detection means, rotation acceleration information calculation means, resonance frequency estimate means for time-series estimating a torsional resonance frequency of the rotation speed information, correlation calculation means for, regarding left and right wheels of driving wheels, calculating a time series correlation of the rotation acceleration information of the left and right wheels, and determination means for determining a decrease in pressure of the tires based on the estimated torsional resonance frequency. In a case where the correlation exceeds a predetermined threshold value, the resonance frequency estimate means stops estimating the torsional resonance frequency.

The present invention relates to a method and an apparatus for monitoring a tire pressure using zero crossing. Provided is a tire pressure monitoring method using zero crossing including: acquiring a wheel speed signal of a vehicle; interpolating the obtained wheel speed signal by a fixed time; calculating a maximum value of the interpolated wheel speed signal using a time range of zero crossing; calculating a changed amount of the maximum value by comparing the maximum value of the calculated wheel speed signal and the maximum value of the predetermined normal pressure; and determining a low pressure of a tire mounted on a vehicle using the calculated changed amount of the maximum value.

A method for ascertaining the deformation of a tire comprises: fastening to the tire a sensor able to generate a signal sensitive to the movement of the sensor; acquiring (201) a temporal wheel-turn signal Sig.sup.TDR (101) comprising the amplitude of the movement while rolling; determining a reference speed W.sup.reference (202) associated with a portion of the wheel-turn signal Sig.sup.TDR; normalizing (203) the portion of the wheel-turn signal Sig.sup.TDR by a variable which is a function F of W.sup.reference; angularly resampling (204) the portion of the wheel-turn signal Sig.sup.TDR; obtaining the spectral signal (205) of the portion of the normalized and angularly resampled wheel-turn Sig.sup.TDR; defining a spectral variable (206); and identifying the deformation of the tire Def % (207) as a function G of the spectral variable.

The present invention relates to an apparatus for monitoring a tire pressure using a mass of a vehicle. Provided is a tire pressure monitoring apparatus using a mass of a vehicle including: a radius analyzing unit; a frequency analyzing unit; a mass estimating unit; a calibration unit; and a low pressure determining unit.

The present invention relates to an apparatus and a method for monitoring a tire pressure using a speed section. The tire pressure monitoring apparatus using a speed section of the present invention includes a frequency measuring unit which measures frequency data for every wheel mounted on a vehicle; a frequency calculating unit which calculates a mean frequency for every speed section by accumulating the measured frequency data for every predetermined speed section to obtain a mean; a frequency calibration unit which performs the frequency calibration by calculating a deviation of the mean frequency for every adjacent speed section and comparing the calculated deviation of the mean frequency with the predetermined frequency range; and a low pressure determining unit which determines a low pressure by performing the frequency analysis in accordance with the speed section in which the frequency calibration is completed.

The present disclosure relates to a tire rotation imbalance detection device and method, and a vehicle provided therewith. A device according to one embodiment of the present disclosure is a device provided in a vehicle, including a memory and a processor configured to perform processing to detect whether tire rotation imbalance occurs using information stored in the memory. The processor is configured to identify an angular velocity () of each of a plurality of tires of the vehicle over time using a sensor signal from a wheel speed sensor installed on the tire, perform Fourier transform on the angular velocity (), and determine whether tire rotation is imbalanced based on signal magnitudes of frequency signals included in a reference region according to the Fourier transform in a frequency domain.