Sumitomo Rubber Industries Limited

Other

Sumitomo Electric Industries, Limited

Toyota Jidosha Kabushiki Kaisha

Honda Motor Co., Ltd.

Advics Co., Ltd.

Sri Sports Limited

Minao Yanase

Yuji Oshiro

Shinzo Kajiwara

Yoshio Konii

Hiroto Horie

Masakazu Arita

Yoshikazu Kishimoto

Yoshikazu Kushimoto

Hideki Ohashi

Motoshi Suzuki

Yukio Nakao

Ichiro Ueno

Seigou Sakagami

Akihiko Nakamura

Kazutaka Saito

Kazuyoshi Miyamoto

Mikao Nakajima

Yasushi Kobayashi

Hidenori Kajino

Shinya Notomi

Masahiro Yonetani

Tomonori Sakai

Kazunari Okada

Masaaki Komazawa

A tire pressure decrease detection apparatus comprising a rotation speed information detection unit for detecting rotation speed information of wheels of a vehicle, a resonance frequency estimate unit for time-series estimating a torsional resonance frequency of the rotation speed information from the rotation speed information obtained by the rotation speed information detection unit, and a judgment unit for judging a decrease in pressure of tires installed in the wheels based on the estimated torsional resonance frequency. The resonance frequency estimate unit includes a noise removal unit for removing a noise superimposed on a wheel speed signal serving as the rotation speed information for each of the wheels with using an active noise control technology.

Tire pressure decrease detection apparatus, method, and program

A system for detecting deflated tires by making a relative comparison among rotation speeds of tires attached to a vehicle. The system includes a rotation speed information detection means for detecting rotation speed information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; and a determination means for determining deflated tires by comparing a decreased pressure determination value using the calculated rotation speeds with a predetermined threshold value. The determination means determines that the vehicle is going straight when it is found, with regard to factors composed of a lateral G, a yaw rate, and a steering angle of the vehicle, at least two of the factors including the yaw rate show that a difference between the maximum value and the minimum value at a predetermined time is lower than a predetermined value, thereby detecting deflated tires.

System, method, and program for detecting deflated tires

A method for detecting a tire having decreased air pressure based on wheel rotation information obtained from the tire attached to a vehicle in which there is a predetermined difference between front and rear wheel loads. The method includes the steps of acquiring wheel rotation information obtained from the tire, storing the wheel rotation information, acquiring a load sensitivity of a tire dynamic loaded radius due to load shift during turning, acquiring speed dependency of the load sensitivity, comparing load sensitivity of the tire dynamic loaded radius at a speed acquired based on the speed dependency with preliminarily stored load sensitivities of dynamic loaded radiuses of various tires, estimating decreased pressure sensitivity of the tire dynamic loaded radius based on a result of the comparison, and determining that the tire has a decreased air pressure based on a result of the estimation.

Method, apparatus, and program for detecting tire having decreased air pressure

The method includes: a step of calculating wheel rotation information; a judgment step of judging a decrease in a tire air pressure by comparing a predetermined reference value with a decreased pressure judgment value showing a wheel speed ratio of the front and rear axes; an initialization step of storing the wheel speed ratio between the front and rear axes at the regular internal pressure; and a step of determining whether the distribution of the front and rear driving torque is equidistribution or not.

Method and apparatus for detecting decrease in tire air pressure and program for determining decrease in tire air pressure

To provide an apparatus, method and program for alarming decrease in tire air-pressure which enable to detect decrease in air-pressure of all of four-wheels tires at reduced costs. The apparatus for alarming decrease in tire air-pressure includes means of (1) detecting decrease in tire air-pressure by measuring change of parameter in relation to resonance condition in the tire, and (2) detecting decrease in tire air-pressure by making relative comparison of dynamic loaded radii of tires, wherein the means (1) is included in one to three-wheel tires on a four-wheel vehicle.

Apparatus, method and program for alarming decrease in tire air-pressure

An apparatus for calculating an initial correction coefficient for correcting rotational angular velocities obtained from outputs of rotational angular velocity detecting means. The apparatus includes a judged value calculating means which calculates a judged value on the basis of the rotational angular velocities; an identifying means which identifies whether the vehicle is performing turning movements at high velocity, straight-ahead running or turning movements at mid/low velocity; and an initial correction coefficient calculating means which obtains an initial correction coefficient when it has been identified by the identifying means that the vehicle is performing straight-ahead running or turning movements at mid/low velocity. It is possible to obtain accurate correction coefficients so that it is possible to accurately detect, for instance, a decrease in tire air-pressure and thus to maintain safe running.

Apparatus and method for calculating initial correction coefficient, and program for calculating initial correction coefficient

A detection method of reducing the air pressure of tires based on the rotational speed of wheels mounted on a vehicle. The method includes steps of: determining the rotational speed of each wheel, memorizing the rotational speed of each wheel, determining the loading sensitivity of the dynamic load radius of tires caused by movement of a load during turning, comparing said loading sensitivity with the loading sensitivity of the dynamic load radii of tires at initialization which are preliminarily memorized, and judging decompression of tires based on the result of the comparison. Further, a loading sensitivity-calculating method of determining the loading sensitivity of the dynamic load radii of tires includes steps of: determining a lateral acceleration during turning of a vehicle, determining the shift rate of a judgment value which is the relative comparison of rotational speed of wheels on a pair of diagonals of a vehicle, and determining the loading sensitivity.

Method and device for detecting decompression of tires, and program for judging decompression of tires

A tire deflation warning system having a means for detecting the rotational speeds of wheels on a vehicle and a means for judging tires with reduced air pressure from the rotational speed information of the wheels including a means for judging whether driving force works to respective wheels or not a means for calculating a vehicle speed when driving force works to respective wheels, a means for comparing the average of the rotational speeds of the driving wheels against the average of the rotational speeds of the following wheels, with the average of the rotational speeds of the driving wheels against the average of the rotational speeds of the following wheels at normal air pressure in running state in which the vehicle has driving force and a means for judging that the air pressures of the all wheels which are mounted on the vehicle are simultaneously reduced, or that the air pressures of the driving wheels are reduced by the result of the comparison.

Tire deflation warning system and method thereof, and judgment program of tire with reduced pressures

A method for detecting decrease in tire air-pressure on the basis of wheel rotational information obtained from tires attached to a four-wheeled vehicle. The method includes the steps of: obtaining wheel rotational information obtainable from the respective tires, storing the wheel rotational information, and judging decrease in air-pressure of a tire. The step of judging decrease in air-pressure includes the step of adjusting a sensitivity of judgment upon multiplying a specified sensitivity coefficient to the wheel rotational information of the respective wheels of a front axis or those of the respective wheels of a rear axis of the vehicle and of judging a running condition of the vehicle. When it is determined that the vehicle is performing straight-ahead running, the judgment of decrease in tire air-pressure is performed only on the basis of wheel rotational information when performing straight-ahead running. It is possible to maintain detection accuracy of decrease in tire air-pressure and to prevent erroneous alarm.

Method and apparatus for detecting decrease in tire air-pressure, and program for judging decompression of tire

A tire air-pressure alarming device includes wheel speed sensors for detecting wheel speeds of wheels of a motor vehicle and also includes a microcomputer-base control device and an alarming unit. The control device is programmed to execute function steps of: deriving a decision value based on the wheel speeds detected by the wheel speed sensors; judging the occurrence of air-pressure drop of the tires constituting wheels, based on the decision value; and outputting a command when the occurrence of the air-pressure drop of the tires is judged. The alarming unit is responsive to the command from the control device thereby to raise an alarm indicating the occurrence of the air-pressure drop of the tire. The tires are monitored by the tire air-pressure alarming device, wherein the control device is also programmed to execute a function step of standardizing the speed dependency of a rolling radius of the tires thereby to standardize the performance in judging the air-pressure drop of the tires. Thus, the tire property can be controlled to improve the accuracy in detecting the tire air-pressure drop.

Tire air-pressure alarming device, tire monitored thereby and control method for properties of tire

A detection method of reduced air pressure of tires based on the rotational speed of wheels mounted on a vehicle. The method includes steps of: determining the rotational speed of each wheel, memorizing the rotational speed of each wheel, determining the loading sensitivity of the dynamic load radius of tires caused by movement of a load during turning, comparing the loading sensitivity with the loading sensitivity of the dynamic load radii of tires at initialization which are preliminarily memorized, and judging decompression of tires based on the result of the comparison. Further, a loading sensitivity-calculating method of determining the loading sensitivity of the dynamic load radii of tires includes steps of: determining a lateral acceleration during turning of a vehicle, determining the shift rate of a judgment value which is the relative comparison of rotational speed of wheels on a pair of diagonals of a vehicle, and determining the loading sensitivity.

A method for detecting decrease in tire air-pressure in which decrease in internal pressure of a tire is detected on the basis of wheel speed information obtained from wheels attached to a vehicle. The method includes the steps of: detecting wheel speed information of the respective tires; storing the wheel speed information of the respective tires; obtaining a vehicle body velocity of the vehicle; obtaining vehicle information of the vehicle during running such as driving force, wheel torque or slip rate; calculating a judged value of decompression; and detecting decrease in air-pressure of a tire upon calculating a multiple correlation coefficient for the judged value between the vehicle body velocity and the vehicle information and comparing the multiple correlation coefficient with a specified threshold. It is possible to accurately detect decompression of a tire.

Method and apparatus for detecting decrease in tire air-pressure and program for judging decompression of tire

A method for detecting decrease in tire air-pressure includes the steps of: detecting rotational angular velocities of respective tires; calculating an initial correction coefficient for a ratio of right and left wheels; terminating initialization of a first stage at a point of time when the initial correction coefficient has been calculated for performing a provisional judgment of decompression; calculating an initial correction coefficient for a ratio of front and rear wheels; and terminating initialization of a second stage at a point of time when the initial correction coefficient has been calculated for performing normal judgement of decompression. Detection of decompression when performing running including mostly straight-ahead running such as driving in an urban area might be made at an early stage and at high accuracy to thereby improve the performance of the system.

A vehicle wheel speed is calculated based on a vehicle wheel speed signal outputted from a vehicle wheel speed sensor and a change width w which is an amplitude of a time change component of the calculated vehicle wheel speed. When the calculated change width w is equal to or more than a reference value wit is judged that a quick tire deformation is currently generated and a driver of the vehicle is informed of the quick deformation by actuating a warning device.

Tire information obtaining device, method for obtaining tire information and tire information obtaining program

A method for estimating a mass of a vehicle including the steps of: correcting a wheel torque of a vehicle during running by using a preliminarily obtained wheel torque necessary for running on a flat surface at constant speed, obtaining a regression line of the corrected wheel torque and an acceleration/deceleration of the vehicle, and estimating a mass of the vehicle on the basis of a slope of the regression line. It is possible to estimate the mass of the vehicle at high accuracy.

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Kobe, Japan

Minao Yanase