Abstract: A circuit board unit includes a first circuit board having a first ground layer, a second circuit board having a second ground layer and arranged so as to be opposed to the first circuit board, a connector unit having a first connector attached to the first circuit board, and a second connector attached to the second circuit board and coupled to the first connector, and a metal member arranged between the first circuit board and the second circuit board, and configured to electrically couple the first ground layer and the second ground layer to each other. The metal member is arranged so as to be adjacent to the connector unit.

Abstract: A device for estimating a state of a road surface on which a tire is running, the device including: an acceleration sensor 11 installed in the tire; an acceleration information acquiring means 12, 13, 14 that acquires acceleration information input to the tire from an output of the acceleration sensor 11; a storage means 15 that stores acceleration information of each road surface roughness set in advance; and a road surface state estimating means 16 that compares the acquired acceleration information with the acceleration information of each road surface roughness stored in the storage means 15 so as to estimate the state of the road surface.

Abstract: A method for determining a state of a road surface in which, a time-series waveform of tire vibration detected by an acceleration sensor is windowed by a windowing means with a time T and a feature vector Xi in each time window is calculated through the extraction of a time-series waveform of the tire-vibration in each time window. Thereafter, in the calculation of a kernel function KA from the feature vector Xi in each time window and a road surface feature vector YAj that is a feature vector in each time window calculated from a time-series waveform of tire-vibration that has been calculated in advance for each road surface state, the feature vector Xi in each time window and the road-surface feature vector YAj are made to be vibration levels of frequency bands of 500 Hz or greater extracted from the time-series waveform in each time window.

Abstract: A sensor case (10) with a sensor housed therein for obtaining information on a tire, including a lower side member (11) having a bottom surface (11b) to be attached on an inner surface of the tire or to a base (20) for mounting the sensor case (10) on the inner surface of the tire, and an upper side member (12) protruding from a surface (11a) opposite to the bottom surface (11b) of the lower side member (11) to a side opposite to the bottom surface (11b) and having a width smaller than a width of the lower side member (11). A side surface (11c) of the lower side member (11) is formed of a curved surface convex outwardly in a width direction, and a side surface (12c) of the upper side member (12) and a top surface (12a) of the upper side member (12), which is a surface opposite to the bottom surface (11b), are connected by a curved surface (12p) being in contact with the top surface (12a).

Abstract: In order to provide a method and a device capable of precisely estimating a load acting on a tire with less sensors, a load estimation device 10 for estimating the load acting on the tire is provided with: an acceleration sensor 11; an acceleration waveform detection means 13 that detects an acceleration waveform in a tire radial direction on the basis of an output of the acceleration sensor 11; a differential acceleration waveform computing means 14 that differentiates the acceleration waveform to obtain a differential acceleration waveform; a peak position detection means 15 that detects a position of a peak on a leading edge side and a position of a peak on a trailing edge side appearing in the differential acceleration waveform; a ground contact time ratio calculation means 16 that calculates a ground contact time and a rotation time on the basis of the peak positions and calculates a ground contact time ratio, which is a ratio between the calculated ground contact time and the rotation time; and a load e

Abstract: A device for estimating a state of a road surface on which a tire is running, the device including: an acceleration sensor 11 installed in the tire; an acceleration information acquiring means 12, 13, 14 that acquires acceleration information input to the tire from an output of the acceleration sensor 11; a storage means 15 that stores acceleration information of each road surface roughness set in advance; and a road surface state estimating means 16 that compares the acquired acceleration information with the acceleration information of each road surface roughness stored in the storage means 15 so as to estimate the state of the road surface.

Abstract: A method and an apparatus configured to acquire, as acceleration information, a peak level ak which is a magnitude of a peak on a positive side or a negative side of an acceleration signal in a tire circumferential direction or a tire width direction detected by an acceleration sensor, or a peak interval bk which is a time interval between peaks, or acquire the peak level ak or the peak interval bk of a differential acceleration signal in a tire radial direction obtained by differentiating the acceleration signal in the tire radial direction; calculate ratios Pk, Qk of a difference between the acquired acceleration information ak, bk and average values Ak?1 of the acceleration information to the average values; and determine that the acceleration sensor is detached from the inside of the tire when the calculated ratio Pk, Qk exceeds a preset threshold value Kp, Kq by multiple times successively.

Abstract: A device for estimating a condition of a road surface on which a tire is travelling, the device including: an acceleration sensor 11 that detects acceleration in a tire radial direction, an acceleration waveform extracting unit 12 that extracts an acceleration waveform from the acceleration, a differential waveform calculating unit 13 that calculates a differential waveform of the acceleration waveform, a rotation time calculating unit 14 that calculates a rotation time of the tire from the differential waveform, a normalized acceleration waveform generating unit 15 that generates a normalized acceleration waveform by using the rotation time, and a road surface condition estimating unit 16 that determines whether or not a water infiltration condition between the tire and the road surface is in a condition to be shifted to a hydroplaning condition.

Abstract: A method and apparatus capable of estimating a tire wear amount even on snow-covered road surfaces accurately and reliably are provided. To that end, a differentiated acceleration waveform of a radial acceleration waveform of a tire is obtained, and an operation of calculating a leading-end differentiated peak value and a trailing-end differentiated peak value from the differentiated acceleration waveform is repeated a plurality of times. At the same time, a differentiated peak ratio, which is a ratio between the leading-end differentiated peak value and the trailing-end differentiated peak value, is calculated for each of the leading-end differentiated peak values and the trailing-end differentiated peak values obtained. Either one of the leading-end differentiated peak values and the trailing-end differentiated peak values, having a differentiated peak ratio within a lower limit range of 0.6 to 0.8 and an upper limit range of 1.0 to 1.

Abstract: A sensor case (10) with a sensor housed therein for obtaining information on a tire, including a lower side member (11) having a bottom surface (11b) to be attached on an inner surface of the tire or to a base (20) for mounting the sensor case (10) on the inner surface of the tire, and an upper side member (12) protruding from a surface (11a) opposite to the bottom surface (11b) of the lower side member (11) to a side opposite to the bottom surface (11b) and having a width smaller than a width of the lower side member (11). A side surface (11c) of the lower side member (11) is formed of a curved surface convex outwardly in a width direction, and a side surface (12c) of the upper side member (12) and a top surface (12a) of the upper side member (12), which is a surface opposite to the bottom surface (11b), are connected by a curved surface (12p) being in contact with the top surface (12a).

Abstract: A method and an apparatus configured to acquire, as acceleration information, a peak level ak which is a magnitude of a peak on a positive side or a negative side of an acceleration signal in a tire circumferential direction or a tire width direction detected by an acceleration sensor, or a peak interval bk which is a time interval between peaks, or acquire the peak level ak or the peak interval bk of a differential acceleration signal in a tire radial direction obtained by differentiating the acceleration signal in the tire radial direction; calculate ratios Pk, Qk of a difference between the acquired acceleration information ak, bk and average values Ak?1 of the acceleration information to the average values; and determine that the acceleration sensor is detached from the inside of the tire when the calculated ratio Pk, Qk exceeds a preset threshold value Kp, Kq by multiple times successively.

Abstract: A method and an apparatus for estimating uneven wear in the tire shoulder with high accuracy using a fewer number of sensors are provided. An uneven tire wear estimating apparatus includes an acceleration sensor (11) disposed on an inner surface of a tire tread for measuring radial acceleration, an acceleration waveform extracting means (12) for extracting an acceleration waveform in a post-trailing-end domain from output signals of the acceleration sensor, means for calculating a vibration level ? of an uneven wear measured band and a vibration level ? of a reference band from the extracted acceleration waveform, an uneven wear determination index calculating means (16) for calculating an uneven wear determination index ?, which is an index for determining au uneven wear, from the vibration level ? and the vibration level ?, and a determining means (18) for determining whether an uneven wear is occurring in an edge of the tire shoulder from the value of the uneven wear determination index ?.

Abstract: In order to provide a method and a device capable of precisely estimating a load acting on a tire with less sensors, a load estimation device 10 for estimating the load acting on the tire is provided with: an acceleration sensor 11; an acceleration waveform detection means 13 that detects an acceleration waveform in a tire radial direction on the basis of an output of the acceleration sensor 11; a differential acceleration waveform computing means 14 that differentiates the acceleration waveform to obtain a differential acceleration waveform; a peak position detection means 15 that detects a position of a peak on a leading edge side and a position of a peak on a trailing edge side appearing in the differential acceleration waveform; a ground contact time ratio calculation means 16 that calculates a ground contact time and a rotation time on the basis of the peak positions and calculates a ground contact time ratio, which is a ratio between the calculated ground contact time and the rotation time; and a load e

Abstract: A method and apparatus capable of estimating a tire wear amount even on snow-covered road surfaces accurately and reliably are provided. To that end, a differentiated acceleration waveform of a radial acceleration waveform of a tire is obtained, and an operation of calculating a leading-end differentiated peak value and a trailing-end differentiated peak value from the differentiated acceleration waveform is repeated a plurality of times. At the same time, a differentiated peak ratio, which is a ratio between the leading-end differentiated peak value and the trailing-end differentiated peak value, is calculated for each of the leading-end differentiated peak values and the trailing-end differentiated peak values obtained. Either one of the leading-end differentiated peak values and the trailing-end differentiated peak values, having a differentiated peak ratio within a lower limit range of 0.6 to 0.8 and an upper limit range of 1.0 to 1.

Abstract: A method and an apparatus for estimating uneven wear in the tire shoulder with high accuracy using a fewer number of sensors are provided. An uneven tire wear estimating apparatus includes an acceleration sensor (11) disposed on an inner surface of a tire tread for measuring radial acceleration, an acceleration waveform extracting means (12) for extracting an acceleration waveform in a post-trailing-end domain from output signals of the acceleration sensor, means for calculating a vibration level ? of an uneven wear measured band and a vibration level ? of a reference band from the extracted acceleration waveform, an uneven wear determination index calculating means (16) for calculating an uneven wear determination index ?, which is an index for determining au uneven wear, from the vibration level ? and the vibration level ?, and a determining means (18) for determining whether an uneven wear is occurring in an edge of the tire shoulder from the value of the uneven wear determination index ?.

Abstract: A method for accurately determining internal failures, such as separations, of a tire without affecting tire behaviors. Radial acceleration signals of a tire during vehicular travel are detected by an acceleration sensor (11) attached to the inner surface of the tire at the axial center of the tread. A frequency analysis is performed on the radial acceleration signals to obtain a frequency spectrum. A band value Xab is calculated of a specific frequency band [fa, fb] within the range of 100 Hz-400 Hz, which includes the frequency of the second lowest peak of the peaks appearing in the frequency spectrum. Then a check is made to see whether or not the difference between this band value Xab and a predetermined band value Yab of a normal tire exceeds a threshold value K. And when Yab?Xab>K, it is determined that an internal failure, such as a separation, is present in the tire.

Abstract: The present invention provides a method and apparatus for accurately detecting shoulder edge wear without impairing the durability of a tire. The method includes extracting an acceleration waveform from output signals of an acceleration sensor (11) disposed on the inner surface of a tire tread by an acceleration waveform extracting means (12), extracting either a pre-leading-end region or a post-trailing-end region of the acceleration waveform by an acceleration waveform separating means (13), obtaining a frequency spectrum by analyzing the extracted acceleration waveform by a frequency analysis means (14), calculating a frequency band value, which is the magnitude of acceleration in a specific frequency band, from the frequency spectrum by a frequency band value calculating means (15), and detecting an uneven wear in the edge of the tire shoulder from the magnitude of the calculated frequency band value by a shoulder edge wear detecting means (17).

Abstract: A method for accurately determining internal failures, such as separations, of a tire without affecting tire behaviors. Radial acceleration signals of a tire during vehicular travel are detected by an acceleration sensor (11) attached to the inner surface of the tire at the axial center of the tread. A frequency analysis is performed on the radial acceleration signals to obtain a frequency spectrum. A band value Xab is calculated of a specific frequency band [fa, fb] within the range of 100 Hz-400 Hz, which includes the frequency of the second lowest peak of the peaks appearing in the frequency spectrum. Then a check is made to see whether or not the difference between this band value Xab and a predetermined band value Yab of a normal tire exceeds a threshold value K. And when Yab?Xab>K, it is determined that an internal failure, such as a separation, is present in the tire.