Sumitomo Rubber Industries Limited

Other

Honda Motor Co., Ltd.

Sumitomo Electric Industries, Limited

Yuji Oshiro

Minao Yanase

Seigou Sakagami

Masashi Kitano

Kazunari Okada

Tomonori Sakai

Shinya Notomi

Hiroaki Kawasaki

Ichiro Ueno

Akihiko Nakamura

Kazutaka Saito

Kazuyoshi Miyamoto

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 system detects deflated tires based on a resonance frequency of tires with a vehicle and a relative comparison value of rotation speeds of the tires. The system includes: a rotation information detection means for detecting rotation information of the tires; a rotation speed calculation means for calculating rotation speeds of the tires; a resonance frequency assumption means for assuming a resonance frequency of the tires; and a determination means for detection of deflated tires using a decreased pressure determination index calculated by a relative comparison of the rotation speeds of the tires and the resonance frequency. The determination means is so configured as to reduce the second threshold to be compared with the decreased pressure determination index to a value equal to or higher than 1% and equal to or lower than 90% and to detect deflated tires when the decreased pressure determination index exceeds the reduced threshold.

An apparatus for detecting a decrease in air pressure of a tire attached to a vehicle includes a rotation speed detection means for periodically detecting rotation speeds of tires of respective wheels of the vehicle; a rotation wheel speed ratio calculation means for calculating a rotation wheel speed ratio between front wheels and rear wheels of the vehicle; a wheel torque calculation means for calculating a wheel torque of the vehicle; an initialization means for obtaining a relation at a normal internal pressure between the wheel torque and the rotation wheel speed ratio; a comparison means for comparing the rotation wheel speed ratio with the rotation wheel speed ratio at a normal internal pressure obtained from the wheel torque and the relation; and a determination means for correcting the comparison result by a front-to-rear direction acceleration and determining whether there is a tire having a decreased air pressure or not.

Apparatus and method for detecting decrease in tire air pressure and program for detecting decrease in tire air pressure

An apparatus includes an acceleration calculation means for calculating, based on rotation speed information obtained from a rotation speed detection means, accelerations of the respective tires; an acceleration variation calculation means for calculating acceleration variations of the tires; a comparison means for comparing the acceleration variations; a presumption means for presuming a pressure decrease of a tire; an examination means for identifying, based on the tire rotation speed information, a tire having a rotation speed that is higher than the rotation speeds of the other tires or that is lower than a predetermined criterion; and a determination means for determining, when a tire identified by the presumption means is identical with a tire identified by the examination means, a pressure decrease of the tire.

Apparatus, method, and program for detecting decrease in tire air pressure

An apparatus includes a rotating wheel speed ratio calculation means for calculating, based on rotation velocity information, a rotating wheel speed ratio between front wheels and rear wheels of the vehicle; a wheel torque calculation means for calculating a wheel torque of the vehicle; an initialization means for obtaining a relation at a normal internal pressure between the wheel torque and the rotating wheel speed ratio between the front wheels and the rear wheels; a storage means for storing the relation obtained; a comparison means for comparing the rotating wheel speed ratio obtained by the rotating wheel speed ratio calculation means with the rotating wheel speed ratio at a normal internal pressure obtained from the wheel torque obtained by the wheel torque calculation means and the relation; and a judgment means for judging whether a tire air pressure is decreased or not based on a comparison result.

An apparatus for detecting a decreased air pressure of a tire includes an acceleration calculation circuit for calculating, based on rotation velocity information of tires of respective wheels of a vehicle; an acceleration variation calculation circuit for calculating acceleration variations of the respective tires; a comparison circuit for comparing the acceleration variations of the respective tires; an estimation component for estimating, when a comparison result of the comparison shows that an acceleration variation of a certain tire is greater than acceleration variations of the other tires, a decrease in air pressure of the certain tire; a test circuit for determining a tire having a rotation velocity that is faster than the rotation velocities of the other tires or that is further slower than a predetermined reference; and a judgment circuit for judging, when a certain tire identified by the estimation is identical with the tire identified by the test, a decrease in air pressure of the certain tire.

It is the purpose of the present invention to provide a method, apparatus and program for alarming abnormality in tire air-pressure capable of precisely detecting decrease in tire air-pressure even at actuation of air suspension in a vehicle equipped with air suspensions. The present invention discloses a method for alarming abnormality in tire air-pressure informing decrease in tire air-pressure mounted on a vehicle, comprising a step of judging whether loads applied on respective tires are changed by the influence of air suspensions based on the difference of the heights of strokes between left wheel and right wheel in a vehicle equipped with the air suspensions and affect the rotational wheel speeds of tires or not, and increasing threshold for carrying out the judgment of decrease in tire air-pressure when the air suspensions provide influence.

Method, apparatus and program for alarming abnormality in tire air-pressure

The present invention provides an apparatus, method and program for detecting abnormality in tire air-pressure which allow detecting abnormality in tire air-pressure even if pressure in a tire is completely zero. The apparatus for alarming abnormality in tire air-pressure includes means of (1) calculating the acceleration variations of respective tires from accelerations of the tires calculated by rotational wheel velocities; (2) comparing the calculated acceleration variations of the respective tires; and (3) detecting air-pressure in a tire is abnormal when the acceleration variation of the tire is larger than the acceleration variations of the remaining tires as a result of comparison.

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

An object of the present invention is to provide a device for detecting as to whether or not the heterogeneous tires are set on the right and left wheels, respectively, and accurately detecting the loss of the pneumatic pressure in the tire, even when heterogeneous tires are set on the right and the left wheels, respectively. This is a method for detecting as to whether or not the kinds of the tires set on a vehicle are different based on the rotational velocity of the wheels set on the vehicle, so that, when the pneumatic pressure of the tire set on said vehicle is normal, the velocity ratios of the right and left front wheels or the velocity ratios of the right and left rear wheels are obtained by each velocity region of the vehicle as described above, and comparison is made between the wheel velocity ratios of the right and left front wheels by each velocity region or between the wheel velocity ratios of the right and left rear wheels by each velocity region, thereby detecting that the heterogeneous tires are set between the right and left sides. Furthermore, the method for detecting loss of the pneumatic pressures of tires according to the present invention is designed to modify the threshold value for judging loss of the pneumatic pressures of the tires based on the results detected by the method for detecting the heterogeneous tires as described above.

Means for detecting loss of pneumatic pressure in tire and device for the purpose

The present invention provides an apparatus, method and program for alarming abnormality in tire air-pressure which prevent the issuance of an erroneous alarm and thus determine abnormality in tire air-pressure even when a rotational velocity of the tire changes by causes other than a decrease in an air pressure. An apparatus for alarming abnormality in tire air-pressure decrease detects a change in a relationship between wheel velocities of front wheel tires and those of rear wheel tires, and replaces a relationship between the wheel velocities of the front wheel tires and those of the rear wheel tires with a relationship between wheel velocities of front wheel tires and those of rear wheel tires obtained after the change of the relationship, thereby determining abnormality in air-pressure when the change is detected.

The present invention provides an apparatus, method and program for alarming abnormality in tire air-pressure which detects abnormality of a tire even under unusual conditions such as offset load on a vehicle or providing a snow chain on one wheel. The apparatus, method and program for alarming abnormality in tire air-pressure include means of comparing rotational wheel velocities of respective tires provided on a vehicle and detecting whether or not rotational wheel velocity of one wheel is slower than those of other wheels by comparing rotational wheel velocities of respective tires provided on a vehicle.

A method, an apparatus and a program for alarming abnormality in tire air-pressure which enables to prevent issuing a erroneous alarm or no alarm when only one tire is replaced with a new tire can be provided. The method of alarming abnormality in tire air-pressure includes a step of detecting whether or not a new tire has been mounted by comparing the difference between determinate values to judge a decrease in air-pressure before and after enlargement of a diameter of the new tire with a set threshold value when solely one tire is replaced with the new tire with the use of a phenomenon that a diameter of a new tire on a vehicle enlarges after running.

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 device, and an analogous method and program, for detecting whether different tires are mounted on the left and right driving wheels of a vehicle and accurately detecting decreased tire pressures. The device detects the rotational speeds of wheels mounted on the vehicle, detects torque applied to driving wheels, and calculates the inclinations of straight lines representing (1) the relation between the rotational speed ratio of the front and rear left side wheels and torque applied to driving wheels and (2) the relation between the rotational speed ratio of the front and rear left side wheels and torque applied to driving wheels. The device compares the inclinations of the lines to detect whether different tires are mounted on the driving wheels. Based on the comparison of the inclinations, the device changes the threshold for judging tire deflation to different values for different tires and tires that are not different.

Detection device for decreased tire pressures and method thereof

A tire deflation warning system, including a device for detecting a rotational velocity of a wheel attached to a vehicle and a device for judging a tire pneumatic pressure drop by determining a reduced pressure judging value that judges the tire pneumatic pressure drop made of difference of rotational velocity sum of two pairs of the wheels which are diagonally disposed in the vehicle, correcting the reduced pressure judging value by multiplying a weight coefficient that continuously varies according to the velocity of the vehicle, and comparing the corrected reduced pressure judging value with a threshold value, wherein it is tentatively judged whether or not there is a reduced pressure wheel; and in the case when it is tentatively judged that a driving wheel is being reduced pressure, the reduced pressure judging value is multiplied by the weight coefficient which is larger than in the case when it is tentatively judged that a driven wheel is being reduced pressure.

Growing community of inventors

Kobe, Japan

Yuji Oshiro