Abstract: A wheel position identification apparatus includes: braking force fluctuation generating means controlling the braking force-applying means to generate a braking force fluctuation of the wheel independently. The apparatus further includes response probability obtaining means for obtaining a presence, or an absence, of a response of the wheel relative to the braking force fluctuation based upon a wheel rotational speed fluctuation of the wheel. The wheel rotational speed fluctuation is obtained from a rotation state sensor mounted on each wheel. The apparatus still further includes associating means for associating the wheel with the braking force-applying means respectively. The association is based upon a combination of a presence, or an absence, of the braking force fluctuation at each braking force-applying means and the presence, or the absence, of the response obtained by the response probability obtaining means.

Abstract: In a disc brake control system for a vehicle, a control unit determines that a brake disc is in a condition of a thermal inclination of brake disc, and further determines that the brake disc is restored from the thermal inclination. The control unit operates an actuator of a disc brake devices to push a brake pad to the brake disc, when it determines that the brake disc is restored from the thermal inclination. According to such operation, the brake pad is moved to its normal position to the brake disc, so that a brake drag of the brake pad to the brake disc is suppressed.

Abstract: A wheel position identification apparatus includes: braking force fluctuation generating means controlling the braking force-applying means to generate a braking force fluctuation of the wheel independently. The apparatus further includes response probability obtaining means for obtaining a presence, or an absence, of a response of the wheel relative to the braking force fluctuation based upon a wheel rotational speed fluctuation of the wheel. The wheel rotational speed fluctuation is obtained from a rotation state sensor mounted on each wheel. The apparatus still further includes associating means for associating the wheel with the braking force-applying means respectively. The association is based upon a combination of a presence, or an absence, of the braking force fluctuation at each braking force-applying means and the presence, or the absence, of the response obtained by the response probability obtaining means.

Abstract: In a disc brake control system for a vehicle, a control unit determines that a brake disc is in a condition of a thermal inclination of brake disc, and further determines that the brake disc is restored from the thermal inclination. The control unit operates an actuator of a disc brake devices to push a brake pad to the brake disc, when it determines that the brake disc is restored from the thermal inclination. According to such operation, the brake pad is moved to its normal position to the brake disc, so that a brake drag of the brake pad to the brake disc is suppressed.

Abstract: A straight running state is accurately determined using only wheel speed data in any running state. Based upon right and left wheel speed values calculated by a wheel speed calculating mechanism (13) from detection values of right and left wheel speed sensors (11, 12), a wheel speed ratio calculating mechanism (21), a distance calculating mechanism (31), and a distance ratio calculating mechanism (32) respectively calculate a right and left wheel speed ratio, an actual running distance, a linear distance, and a distance ratio of the two distances at every preset checkpoint (CP). A wheel speed ratio change amount evaluating mechanism (24) extracts CPs at times where a change amount of the wheel speed ratio is relatively small as effective CPs, and a determining mechanism (43) determines an effective CP with the smallest distance ratio from among the effective CPs as in a straight running state.

Abstract: A tire air pressure detection device includes an ideal driving status calculating portion (3e) and a rotational status value compensating portion (3f). The ideal driving status calculating portion calculates an ideal status value (?id) corresponding to a slip value under an ideal driving status without tire slippage. The rational status value compensating portion calculates and ideal rotational status value under the ideal driving status without tire slip based on the regression line calculated by a regression line calculating portion (3d) and the ideal slip status value calculated by the ideal driving status calculating portion.

Abstract: A straight running state is accurately determined using only wheel speed data in any running state. Based upon right and left wheel speed values calculated by a wheel speed calculating mechanism (13) from detection values of right and left wheel speed sensors (11, 12), a wheel speed ratio calculating mechanism (21), a distance calculating mechanism (31), and a distance ratio calculating mechanism (32) respectively calculate a right and left wheel speed ratio, an actual running distance, a linear distance, and a distance ratio of the two distances at every preset checkpoint (CP). A wheel speed ratio change amount evaluating mechanism (24) extracts CPs at times where a change amount of the wheel speed ratio is relatively small as effective CPs, and a determining mechanism (43) determines an effective CP with the smallest distance ratio from among the effective CPs as in a straight running state.

Abstract: A tire air pressure detection device of the present invention includes a warning anticipation timing calculating portion for anticipating a warning timing at which tire air pressure decrease detecting portion will detect the tire air pressure decrease based on rotational status value compensated for by a rotational status value compensating portion. A tire air pressure decrease detecting portion detects a decrease in tire air pressure when a clocked determination time reaches the warning anticipation timing anticipated by the warning anticipation timing calculating portion.

Abstract: A tire pneumatic pressure detector includes a tire pneumatic pressure detection unit, a first memory storing data associated with a timing at which the drop of tire pneumatic pressure occurs, a second memory storing second data including one or more of a lapse of time from which the tire pneumatic pressure drop occurs, and third data associated with running distance from the timing when a fault diagnosis signal is input.

Abstract: The invention provides an apparatus and a method of estimating tire air pressure with high accuracy from vehicle operation at low at high speeds regardless of various elements to be mounted to the vehicle. Estimation of tire air pressure based on a resonance frequency extracted based on a wheel speed signal outputted from a wheel speed sensor corresponding to the respective tire and estimation of tire air pressure based on a dynamic load radius derived based on the wheel speed signal, are used to selectively switch in accordance with a magnitude of a variance value of the resonance frequency at a plurality of time points.

Abstract: A tire air pressure detection device includes an ideal driving status calculating portion (3e) and a rotational status value compensating portion (3f). The ideal driving status calculating portion calculates an ideal status value (&bgr;id) corresponding to a slip value under an ideal driving status without tire slippage. The rational status value compensating portion calculates and ideal rotational status value under the ideal driving status without tire slip based on the regression line calculated by a regression line calculating portion (3d) and the ideal slip status value calculated by the ideal driving status calculating portion.

Abstract: A variable value (dynamic load radial deviation &bgr;) for making determination of a tire air pressure is calculated from pulse number cumulative values PFL, PFR, PRL and PRR that are cumulated for individual wheels when a predetermined condition is fulfilled. The calculated variable value is stored as a reference variable value, and a speed of a vehicle at the time when the reference variable value is calculated is stored as a reference vehicle speed associated with the reference variable value. If the value is newly calculated, it is determined whether or not a vehicle speed at that moment is within a predetermined vehicle speed range determined by the reference vehicle speed. If it is determined that the vehicle speed is within the predetermined vehicle speed range, it is determined, based on a difference between the newly calculated variable value and the reference variable value associated with the reference vehicle speed, whether or not the tire air pressure is normal.

Abstract: A tire air pressure detection device of the present invention includes a warning anticipation timing calculating portion for anticipating a warning timing at which tire air pressure decrease detecting portion will detect the tire air pressure decrease based on rotational status value compensated for by a rotational status value compensating portion. A tire air pressure decrease detecting portion detects a decrease in tire air pressure when a clocked determination time reaches the warning anticipation timing anticipated by the warning anticipation timing calculating portion.

Abstract: In a tire air pressure warning device, an outside impact such as hydraulic brake pressure is intentionally applied in a pulsating way to a tire when the vehicle substantially stops so as to exert vibration (rotation variation) of the tire axle. Through data processes in analyzing signals of wheel speed sensors that reflect the rotation variation of the tire axle, tire air pressure is estimated for informing to a driver abnormal tire air pressure.

Abstract: The invention provides an apparatus and a method of estimating tire air pressure with high accuracy from vehicle operation at low at high speeds regardless of various elements to be mounted to the vehicle. Estimation of tire air pressure based on a resonance frequency extracted based on a wheel speed signal outputted from a wheel speed sensor corresponding to the respective tire and estimation of tire air pressure based on a dynamic load radius derived based on the wheel speed signal, are used to selectively switch in accordance with a magnitude of a variance value of the resonance frequency at a plurality of time points.

Abstract: Data about a running distance from a time at which the drop of a tire pneumatic pressure occurs is stored, and a warning method of an alarm is changed in accordance with this data. For example, when the running distance is smaller than a predetermined value, a flashing frequency of an alarm lamp provided to the alarm is set to a lower frequency, and when the running distance becomes greater than the predetermined value, the flashing frequency of the alarm lamp is set to a higher frequency. When a fault-diagnosing device is connected to a tire pneumatic pressure detector, the data about the running distance from the timing of the occurrence of the drop of the tire pneumatic pressure can be read out. In consequence, the tire pneumatic pressure detector can judge the degrees of blowout and the drop of the pneumatic pressure. Further, market data about the blowout of the tire and the running after the drop of the pneumatic pressure can be collected.

Abstract: In a tire air pressure estimating apparatus, wheel speeds of respective wheels are successively calculated when a vehicle is running. At least one of a tire resonance frequency and a tire spring constant is extracted from vibration frequency components included in a wheel speed signal with respect to each of tires. Tire air pressures of drive wheels are estimated based on the extracted tire resonance frequencies or the tire spring constants. Rotational state values (e.g. wheel speed values) of driven wheel tires are calculated based on the detected wheel speeds. Tire air pressures of driven wheels are estimated based on a deviation of the rotational state values of the driven wheel tires.

Abstract: An integrated value &Dgr;tsum of pulse intervals &Dgr;t during one rotation of a signal rotor is computed, and the integrated value &Dgr;tsum is updated by replacing the pulse interval achieved one rotation ago with a newly obtained pulse interval &Dgr;t(m) after exceeding one rotation, while determining an average pulse interval &Dgr;tave which is an average value of the integrated value &Dgr;tsum. That is, the pulse information is extracted on the basis of time information required for one rotation of the tire. After the one rotation of the tire, pulse information having the same uniformity as one rotation ago is regained. Therefore, it is possible to easily obtain pulse information with the uniformity cancelled, by replacing the pulse information achieved one rotation ago with the newly obtained pulse information.

Abstract: A variable value (dynamic load radial deviation &bgr;) for making determination of a tire air pressure is calculated from pulse number cumulative values PFL, PFR, PRL and PRR that are cumulated for individual wheels when a predetermined condition is fulfilled. The calculated variable value is stored as a reference variable value, and a speed of a vehicle at the time when the reference variable value is calculated is stored as a reference vehicle speed associated with the reference variable value. If the value is newly calculated, it is determined whether or not a vehicle speed at that moment is within a predetermined vehicle speed range determined by the reference vehicle speed. If it is determined that the vehicle speed is within the predetermined vehicle speed range, it is determined, based on a difference between the newly calculated variable value and the reference variable value associated with the reference vehicle speed, whether or not the tire air pressure is normal.

Abstract: A signal processor comprises wheel speed-detecting means for detecting a wheel speed signal including vibrational components of a tire, extraction means for extracting a resonant frequency of the vibrational components of the tire or a tire spring constant based on the wheel speed signals, air pressure-estimating means for estimating a tire air pressure based on the resonant frequency or the tire spring constant, and determining means for determining whether the estimated tire air pressure is abnormal or not by comparing with a determination value. Further, correcting means corrects at least one of the determination value, the estimated tire air pressure, the resonant frequency and the tire spring constant in response to a tire temperature. A temperature-sensing device is mounted inside the signal processor to detect a temperature associated with the tire temperature.