Abstract: Provided is a method for detecting decrease in an inner pressure of a tire with excellent accuracy by calculating accurate dynamic load radii by comparing the GPS speed information with tire rotational speed information collecting data only when a stable measurement of the dynamic load radii is possible, as well as by utilizing GPS positioning information for a running state of a vehicle, and an apparatus and a program thereof.

Abstract: A magnetic bias film 9 includes a magnetic bias magnet 11 that has magnetic layers and generates a magnetic field within a plane perpendicular to a lamination direction of the magnetic layers, which is manufactured in the shape of substantially a rectangular prism having a long side, a short side, and a thickness (in the lamination direction) in order of decreasing lengths. A ratio of the long side with respect to the short side of the magnetic bias magnet 11 in length is in a range of 5 to 200.

Abstract: A pneumatic tire (1) has a tire cavity surface (HS) to which an accommodation tool (11) for accommodating an electronic component is bonded. The accommodation tool (11) includes an accommodation space (10) for accommodating an electronic component (W) therein, and includes a bonding region (11Sb) which is bonded to the tire cavity surface (HS) and which is provided on one end of a back surface (11S) directed to the tire cavity surface (HS). Only the bonding region (11Sb) is bonded to the tire cavity surface (HS), thereby making it possible to separate a portion of a non-bonding region (11Sa) on the side of the other end of the back surface (11S) from the tire cavity surface (HS).

Abstract: 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 w0 it 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.

Abstract: A judgment method of road surface condition includes steps of: periodically detecting the wheel rotational speeds of the four wheel tires of a vehicle, memorizing the wheel rotational speed of each of tires, determining a slip ratio from said wheel rotational speeds, determining the acceleration or deceleration of the vehicle, determining a relation equation between said slip ratio and the acceleration or deceleration of the vehicle, determining a judgment value for judging a friction coefficient between the road surface and tires based on the slope of said relation equation determined, and setting a threshold which is used for judging the friction coefficient from the judgment value using the information of wireless tags which were buried in the tires.

Abstract: A method for alarming decrease in tire air-pressure. The method includes the steps of: detecting rotational information of respective tires; respectively calculating and storing a wheel speed, a vehicle acceleration, a slip ratio between front and rear wheels, a running distance and a turning radius; accumulating the running distance, the moving-averaged vehicle acceleration and the slip ratio between front and rear wheels; obtaining a linear regression coefficient and a correlation coefficient of the vehicle acceleration and the slip ratio; judging whether at least a driving wheel tire has decompressed upon comparing a judged value of the linear regression coefficient and a reference value for internal pressure of the linear regression coefficient; and issuing an alarm of decrease in tire air-pressure.

Abstract: A method for judging road surface conditions for judging road surface conditions on which a vehicle is running. The method includes the steps of: obtaining wheel speed rotational information of driving wheels of the vehicle during running from wheel speed detecting means, receiving GPS radio waves to calculate positional information, and judging road surface conditions during running on the basis of a relationship between the wheel speed rotational information and the positional information. Conditions of road surfaces on which a vehicle is running can be accurately judged.

Abstract: 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 w0 it 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.

Abstract: A method for detecting abnormalities of a tire which detects abnormalities of a tire on the basis of rotational information obtained from tires attached to wheels of a vehicle. The method includes the steps of: detecting rotational pulses of wheels of the tires, calculating and storing rotational information of the tires on the basis of the rotational pulses, calculating and processing fluctuations in rotational pulse intervals in a single rotation of the tires on the basis of the rotational information, and storing data during driving which have been processed for each single rotation and performing prediction of abnormalities of a tire on the basis of changes in the data. Irregularities in rotational information of rotational pulses in a single rotation of the tires are detected for predicting a danger of abnormalities occurring to the tires to thus enable safe driving.

Abstract: A method and an apparatus for judging road surface conditions are disclosed. The method includes the steps of: detecting rotational information of tires; storing the rotational information of the respective tires; calculating a vehicle velocity; calculating an acceleration/deceleration of the vehicle; calculating a slip ratio of left-sided front and rear wheels and right-sided front and rear wheels and a slip ratio of front and rear wheels, respectively; calculating an amount of fluctuation in differences in slip ratios between the right and left wheels; obtaining a linear regression coefficient and a correlation coefficient between the slip ratio of the front and rear wheels and the acceleration/deceleration of the vehicle; and setting a threshold for judging road surface conditions. The method and apparatus allow for road surface conditions to be judged accurately.

Abstract: A method for alarming decrease in tire air-pressure. The method includes the steps of: detecting rotational information of respective tires; respectively calculating and storing a wheel speed, a vehicle acceleration, a slip ratio between front and rear wheels, a running distance and a turning radius; accumulating the running distance, the moving-averaged vehicle acceleration and the slip ratio between front and rear wheels; obtaining a linear regression coefficient and a correlation coefficient of the vehicle acceleration and the slip ratio; judging whether at least a driving wheel tire has decompressed upon comparing a judged value of the linear regression coefficient and a reference value for internal pressure of the linear regression coefficient; and issuing an alarm of decrease in tire air-pressure.

Abstract: An apparatus for identifying tires comprising: a rotational speed detecting means; a first calculating means for calculating a vehicle speed; a second calculating means for calculating acceleration/deceleration of the vehicle; a third calculating means for calculating a slip ratio; a fourth calculating means for respectively obtaining moving averages of the acceleration/deceleration and the slip ratios of the vehicle; a fifth calculating means for obtaining linear regression coefficients and correlation coefficients of the moving-averaged acceleration/deceleration of the vehicle and the slip ratio; a sixth calculating means for calculating a tire identifying coefficient; and a tire identifying means for identifying tires which is presently mounted based on the tire identifying coefficient. Differences in tread rigidities of the tires can be automatically reflected for controlling the vehicle.

Abstract: An apparatus for determining a condition of road surface comprising: rotational speed detecting means for periodically detecting rotational speeds of four tires of a vehicle; first computing means for computing a slip ratio from measurement values of the rotational speed detecting means; second computing means for obtaining a relational formula between the slip ratio and either the acceleration or deceleration of the vehicle; and friction coefficient judging means for judging a coefficient of friction occurring between a road and a tire on the basis of a slope of the relational formula obtained by the second computing means. The road friction coefficient can be judged with high accuracy in a short time using only the wheel rotational speed information of four wheels, whereby the performance and safety of a vehicle can be increased.

Abstract: A system for distributing road surface information comprising means for sensing numerical information on slipperiness of a road surface; means for sensing positional information of the travelling vehicle; means for transmitting the numerical information and/or positional information from the vehicle; means for collecting the information transmitted by a plurality of vehicles; means for preparing road surface information of a road on the basis of each information; means for distributing the road surface information also to a vehicle other than the vehicle; and means for receiving the distributed road surface information. By changing a parameter of road surface information in a vehicle movement control system such as an ABS or a VSC, the performance of the control can be improved.

Abstract: A method for judging road surface conditions, comprising the steps of: detecting rotational information of tires; storing the rotational information of the respective tires; calculating a vehicle velocity; calculating an acceleration/deceleration of the vehicle; calculating a slip ratio of left-sided front and rear wheels and right-sided front and rear wheels and a slip ratio of front and rear wheels, respectively; calculating an amount of fluctuation in differences in slip ratios between the right and left wheels; obtaining a linear regression coefficient and a correlation coefficient between the slip ratio of the front and rear wheels and the acceleration/deceleration of the vehicle; and setting a threshold for judging road surface conditions.

Abstract: A method for detecting abnormalities of a tire which detects abnormalities of a tire on the basis of rotational information obtained from tires attached to wheels of a vehicle. The method includes the steps of: detecting rotational pulses of wheels of the tires, calculating and storing rotational information of the tires on the basis of the rotational pulses, calculating and processing fluctuations in rotational pulse intervals in a single rotation of the tires on the basis of the rotational information, and storing data during driving which have been processed for each single rotation and performing prediction of abnormalities of a tire on the basis of changes in the data. Irregularities in rotational information of rotational pulses in a single rotation of the tires are detected for predicting a danger of abnormalities occurring to the tires to thus enable safe driving.

Abstract: An apparatus for detecting decrease in air-pressure for use in a two-wheeled vehicle including: a wheel speed detecting means for detecting wheel speeds; an acceleration calculating means for obtaining accelerations of a vehicle body of the two-wheeled vehicle; a slip rate calculating means for calculating slip rates when the acceleration of the vehicle body is in a specified range which is proximate to zero; an average value calculating means for obtaining average values of the slip rates and average vehicle body speeds; a difference calculating means for obtaining differences between the average values of the slip rates and a reference value which is based on an average vehicle body speed as preliminarily set when an internal pressure is normal; and a means for judging decrease in internal pressure. A decrease in air-pressure in a two-wheeled vehicle can be judged so as to enable safe driving.

Abstract: An apparatus for detecting decrease in air-pressure for use in a two-wheeled vehicle including: a wheel speed detecting means for detecting wheel speeds; an acceleration calculating means for obtaining accelerations of a vehicle body of the two-wheeled vehicle; a slip rate calculating means for calculating slip rates when the acceleration of the vehicle body is in a specified range which is proximate to zero; an average value calculating means for obtaining average values of the slip rates and average vehicle body speeds; a difference calculating means for obtaining differences between the average values of the slip rates and a reference value which is based on an average vehicle body speed as preliminarily set when an internal pressure is normal; and a means for judging decrease in internal pressure. A decrease in air-pressure in a two-wheeled vehicle can be judged so as to enable safe driving.

Abstract: An apparatus for determining a condition of road surface comprising: rotational speed detecting means for periodically detecting rotational speeds of four tires of a vehicle; first computing means for computing a slip ratio from measurement values of the rotational speed detecting means; second computing means for obtaining a relational formula between the slip ratio and either the acceleration or deceleration of the vehicle; and friction coefficient judging means for judging a coefficient of friction occurring between a road and a tire on the basis of a slope of the relational formula obtained by the second computing means. The road friction coefficient can be judged with high accuracy in a short time using only the wheel rotational speed information of four wheels, whereby the performance and safety of a vehicle can be increased.

Abstract: An apparatus for identifying tires comprising: a rotational speed detecting means; a first calculating means for calculating a vehicle speed; a second calculating means for calculating acceleration/deceleration of the vehicle; a third calculating means for calculating a slip ratio; a fourth calculating means for respectively obtaining moving averages of the acceleration/deceleration and the slip ratios of the vehicle; a fifth calculating means for obtaining linear regression coefficients and correlation coefficients of the moving-averaged acceleration/deceleration of the vehicle and the slip ratio; a sixth calculating means for calculating a tire identifying coefficient; and a tire identifying means for identifying tires which is presently mounted based on the tire identifying coefficient. Differences in tread rigidities of the tires can be automatically reflected for controlling the vehicle.