Abstract: A lane departure prevention apparatus (17) has: a controlling device (172) configured to control a braking device (122) so that prevention yaw moment for preventing a vehicle from departing from a driving lane; and determining device (173) configured to determine whether or not slip ratio of a front wheel is larger than a first threshold value (KSfr) and whether or not slip ratio of a rear wheel is larger than a second threshold value (KSrr), the controlling device is configured to control the braking device so that the braking force applied from the braking device becomes smaller than the braking force for applying the prevention yaw moment, if it is determined that the slip ratio of the front wheel is larger than the first threshold value and/or the slip ratio of the rear wheel is larger than the second threshold value.

Abstract: A lane departure prevention apparatus (17) has: a controlling device (172) configured to control a braking device (122) so that prevention yaw moment for preventing a vehicle from departing from a driving lane; and determining device (173) configured to determine whether or not slip ratio of a front wheel is larger than a first threshold value (KSfr) and whether or not slip ratio of a rear wheel is larger than a second threshold value (KSrr), the controlling device is configured to control the braking device so that the braking force applied from the braking device becomes smaller than the braking force for applying the prevention yaw moment, if it is determined that the slip ratio of the front wheel is larger than the first threshold value and/or the slip ratio of the rear wheel is larger than the second threshold value.

Abstract: The present invention provides a vehicle-speed estimation device capable of obtaining vehicle speed with high accuracy, thereby simultaneously detecting decrease of air pressure in all wheels by using the vehicle speed. The vehicle-speed estimation device includes means for detecting lateral acceleration of a vehicle, means for detecting a yaw rate of the vehicle, means for detecting a roll angle of the vehicle, and speed estimation and calculation means for estimating vehicle speed from the lateral acceleration, yaw rate and roll angle. Alternatively, the device includes means for detecting lateral acceleration of a vehicle, means for detecting a yaw rate of the vehicle, and speed estimation and calculation means for estimating vehicle speed from the lateral acceleration and the yaw rate.

Abstract: A method for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle. Respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not are changed depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements. It is possible to improve the detection accuracy without issuing an erroneous alarm even in the case where a large driving force is applied when the vehicle is, for instance, running on a climbing road or when it performs trailer towing.

Abstract: A method for detecting decrease in internal pressure of a tire mounted to a vehicle on the basis of rotational information obtained from the tire. The method includes the steps of: detecting the rotational information of the respective tires; storing the rotational information of the respective tires; calculating a front and rear wheel ratio which can be obtained on the basis of rotational information of both front wheels and rotational information of both rear wheels of the vehicle; calculating a driving wheel torque of the vehicle; and obtaining a value of the front and rear wheel ratio when the driving wheel torque is zero on the basis of a relationship between the front and rear wheel ratio and the driving wheel torque. It is possible to shorten the time for obtaining effective front and rear wheel ratios.

Abstract: A method of detection of the limited slip differential device, wherein it is detected whether a vehicle is mounted with a limited slip differential device on the basis of a relationship between a lateral directional acceleration of a vehicle calculated by using rotational information obtained from tires attached to the vehicle or on the basis of a turning radius of the vehicle, and a specified judged value. It is possible to improve performance and safety of the vehicle since it is possible to accurately judge decrease in internal pressure of a tire.

Abstract: A method for alarming decrease in tire air-pressure in which decrease in tire air-pressure is determined on the basis of rotational velocity information of a wheel of a vehicle. Respective thresholds for determining whether judgment of decrease in tire air-pressure is to be made or not are changed depending on magnitude of driving torque of the vehicle when the vehicle is performing turning movements. It is possible to improve the detection accuracy without issuing an erroneous alarm even in the case where a large driving force is applied when the vehicle is, for instance, running on a climbing road or when it performs trailer towing.

Abstract: A method for detecting decrease in internal pressure of a tire mounted to a vehicle on the basis of rotational information obtained from the tire. The method includes the steps of: detecting the rotational information of the respective tires; storing the rotational information of the respective tires; calculating a front and rear wheel ratio which can be obtained on the basis of rotational information of both front wheels and rotational information of both rear wheels of the vehicle; calculating a driving wheel torque of the vehicle; and obtaining a value of the front and rear wheel ratio when the driving wheel torque is zero on the basis of a relationship between the front and rear wheel ratio and the driving wheel torque. It is possible to shorten the time for obtaining effective front and rear wheel ratios.

Abstract: A method for alarming decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed. A plurality of thresholds for judging bad road are set. Decrease in air-pressure of a tire can be judged and alarm is issued upon decrease in air-pressure also when running on a bad road so that it is possible to secure safe driving for the driver.

Abstract: A method of detection of the limited slip differential device, wherein it is detected whether a vehicle is mounted with a limited slip differential device on the basis of a relationship between a lateral directional acceleration of a vehicle calculated by using rotational information obtained from tires attached to the vehicle or on the basis of a turning radius of the vehicle, and a specified judged value. It is possible to improve performance and safety of the vehicle since it is possible to accurately judge decrease in internal pressure of a tire.

Abstract: An apparatus for alarming a decrease in internal pressure of tires attached to a four-wheeled vehicle using judgement values obtained based on rotational information obtained from the tires. The apparatus comprises rotational information detecting means for detecting rotational information on each of the tires; memory means for storing the rotational information; arithmetic processing means for processing a judgement value from the rotational information; and judgement value correcting means for correcting the judgement value using a weight determined based on a rudder angle obtained by a rudder angle sensor attached to a steering wheel. The frequency of the occurrence of erroneous alarms during cornering can be reduced. As a result, it is possible to improve accuracy for detecting the pressure reduction of tires.

Abstract: An apparatus for alarming decrease in tire air-pressure which detects the decrease in internal pressure of the tire based on wheel speed information obtained from wheels of a vehicle and accordingly alarms a driver. The apparatus comprises: a wheel speed information detecting means, a memory means for storing the wheel speed information of the respective tires, a calculating means for calculating a judged value based on a vehicle velocity and wheel speed information, and a judging means for determining a decrease in tire air-pressure based on correlation of the vehicle velocity and an outer diameter of the tire at the time of performing high-speed running. It is possible to determine a decompression of a tire based on the correlation also in case the judged value will not become large owing to increased influence of centrifugal force during high-speed running even though a tire is in a decompressed condition.

Abstract: A method for alarming decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed. A plurality of thresholds for judging bad road are set. Decrease in air-pressure of a tire can be judged and alarm is issued upon decrease in air-pressure also when running on a bad road so that it is possible to secure safe driving for the driver.

Abstract: An apparatus for alarming decrease in tire air-pressure based on rotational information obtained from tires, comprising a rotational information detecting means for detecting rotational information of each tire, a steering angle detecting means, a memory means for storing the rotational information of each tire and the steering angle, a turning radius calculating and processing means, a judged value calculating and processing means, and a correction means for correcting the turning radius. It is possible to obtain an accurate turning radius also in case any tire of the following wheels is decompressed by correcting the turning radius obtained on the basis of rotational information by using the steering angle information, thereby the DEL value might be obtained in a more accurate manner than compared to conventional arrangements.

Abstract: An apparatus for alarming a decrease in tire air-pressure by using a judged value calculated based on rotational information obtained from tires fitted to a four-wheeled vehicle. The apparatus comprises: traveling determining means for determining whether the vehicle should be stopped at once or the vehicle can still travel to some extent; vehicle position detecting means; collating means for collating the detected vehicle traveling position with positional information on a blowout repairing facility; facility calling means for calling a nearest blowout repairing facility; and display means for displaying a route from the vehicle traveling position to the called facility. The apparatus according to the present invention can teach the route to the blowout repairing facility after giving the alarm of the decrease in tire pressure, thus achieving the repairing of blown-out tire after the safe traveling.

Abstract: An apparatus for alarming decrease in tire air-pressure which detects the decrease in internal pressure of the tire based on wheel speed information obtained from wheels of a vehicle and accordingly alarms a driver. The apparatus comprises: a wheel speed information detecting means, a memory means for storing the wheel speed information of the respective tires, a calculating means for calculating a judged value based on a vehicle velocity and wheel speed information, and a judging means for determining a decrease in tire air-pressure based on correlation of the vehicle velocity and an outer diameter of the tire at the time of performing high-speed running. It is possible to determine a decompression of a tire based on the correlation also in case the judged value will not become large owing to increased influence of centrifugal force during high-speed running even though a tire is in a decompressed condition.

Abstract: An apparatus for alarming a decrease in tire air-pressure by using a judged value calculated based on rotational information obtained from tires fitted to a four-wheeled vehicle. The apparatus comprises: traveling determining means for determining whether the vehicle should be stopped at once or the vehicle can still travel to some extent; vehicle position detecting means; collating means for collating the detected vehicle traveling position with positional information on a blowout repairing facility; facility calling means for calling a nearest blowout repairing facility; and display means for displaying a route from the vehicle traveling position to the called facility. The apparatus according to the present invention can teach the route to the blowout repairing facility after giving the alarm of the decrease in tire pressure, thus achieving the repairing of blown-out tire after the safe traveling.

Abstract: An apparatus for alarming decrease in tire air-pressure based on rotational information obtained from tires, comprising a rotational information detecting means for detecting rotational information of each tire, a steering angle detecting means, a memory means for storing the rotational information of each tire and the steering angle, a turning radius calculating and processing means, a judged value calculating and processing means, and a correction means for correcting the turning radius. It is possible to obtain an accurate turning radius also in case any tire of the following wheels is decompressed by correcting the turning radius obtained on the basis of rotational information by using the steering angle information, thereby the DEL value might be obtained in a more accurate manner than compared to conventional arrangements.

Abstract: An apparatus for alarming a decrease in internal pressure of tires attached to a four-wheeled vehicle using judgement values obtained based on rotational information obtained from the tires. The apparatus comprises rotational information detecting means for detecting rotational information on each of the tires; memory means for storing the rotational information; arithmetic processing means for processing a judgement value from the rotational information; and judgement value correcting means for correcting the judgement value using a weight determined based on a rudder angle obtained by a rudder angle sensor attached to a steering wheel. The frequency of the occurrence of erroneous alarms during cornering can be reduced. As a result, it is possible to improve accuracy for detecting the pressure reduction of tires.