Abstract: pg,2 A vehicle dynamic control system carries out smooth and natural vehicle dynamic control even when road data are discontinuous. In this system, a vehicle dynamic control value calculator calculates a vehicle dynamic control value based on vehicle running conditions and road data from a road data recognizer. The vehicle dynamic control value calculator, upon receipt of a discord signal and after a predetermined number of calculation cycles pass, reduces gradually the vehicle control value to 0 (zero). The calculator increases the vehicle dynamic control value gradually to a value corresponding to the road data and the vehicle running conditions in a predetermined number of calculation cycles, when reception of the discord signal is discontinued. When the calculator receives the discord signal but a predetermined number of calculation cycles are not counted yet, the vehicle dynamic control value is calculated based on road data previously detected.

Abstract: A road friction coefficient detecting apparatus and method of a vehicle includes a vehicle data calculating section, a tire characteristic initial value judging section and a road friction coefficient estimating section. In the vehicle data calculating section, parameters needed for the calculation of road friction coefficients are established based on signals from a steering wheel rotation angle sensor, a vehicle speed sensor and a yaw rate sensor. The tire characteristic initial value judging section sends a signal to establish parameters corresponding to a low friction coefficients to the vehicle data calculating section, when road condition sensing means such as an outside air temperature, a rain fall sensor and the like detect a road surface having a relatively low friction coefficient.

Abstract: A braking force control system and method of a vehicle comprises a steering angle detecting section for detecting a steering angle, a vehicle speed detecting section for detecting a vehicle speed, an actual yaw rate detecting section for detecting an actual yaw rate, a target yaw rate calculating section for calculating a target yaw rate, a target yaw rate restricting section for restricting the target yaw rate to an upper limit value, a yaw rate deviation calculating section for calculating a yaw rate deviation of the actual yaw rate and the target yaw rate, a target braking force calculating section for calculating a target braking force, a braking wheel determining section for determining a braking wheel, an output judging section for judging whether the yaw rate deviation is in a control zone or in a noncontrol zone.

Abstract: A braking force control system and method of a vehicle comprises a steering angle detecting section for detecting a steering angle, a vehicle speed detecting section for detecting a vehicle speed, an actual yaw rate detecting section for detecting an actual yaw rate, a target yaw rate calculating section for calculating a target yaw rate, a target yaw rate restricting section for restricting the target yaw rate to an upper limit value, a yaw rate deviation calculating section for calculating a yaw rate deviation of the actual yaw rate and the target yaw rate, a target braking force calculating section for calculating a target braking force, a braking wheel determining section for determining a braking wheel, an output judging section for judging whether the yaw rate deviation is in a control zone or in a noncontrol zone.

Abstract: A braking force control system and method of a vehicle includes a vehicle speed detecting section, a steering angle detecting section, a yaw rate detecting section, a target yaw rate calculating section, a yaw rate deviation calculating section, turning requirement detecting means for detecting a driver's requirement to turn the vehicle, brake pressure correction coefficient generating section, a target braking force calculating section, a braking force correction section for correcting the braking force according to the driver's requirement to turn the vehicle, a braking wheel determining section for determining an object wheel to apply brakes, an output judging section, a brake signal outputting section and a brake drive apparatus for applying brake pressure to the wheel cylinder of the object wheel. Whereby, the driver can make a sharp turn even when the normal braking force control is operative.

Abstract: A braking force control system comprises a yaw rate sensor for detecting an actual yaw rate of a vehicle, a target yaw rate calculating section for detecting a vehicle speed and a steering angle to calculate a target yaw rate, a yaw-rate difference calculating section for calculating a difference in yaw rate by subtracting the target yaw rate from the actual yaw rate, and a braked-wheel discriminating section for selecting a rear-inside wheel as a braked wheel when the sign of the actual yaw rate is different from that of the difference in yaw rate, and for selecting a front-outside wheel as the braked wheel when the sign of the actual yaw rate is the same as that of the difference in yaw rate. Therefore, when the vehicle is in an under-steering tendency, the rear-inside wheel is selected, and when it is in an over-steering tendency, the front-outside wheel is selected.

Abstract: A traction control system and method of a four-wheel drive vehicle comprises an engine control apparatus, a brake drive apparatus for automatically and independently applying brake to each of four wheels, wheel speed detecting means, vehicle speed detecting means, steering angle detecting means, yaw rate detecting means, target yaw rate calculating means, yaw rate deviation calculating means, slip amount calculating means for calculating an actual slip amount, reference slip amount storing means for memorizing a reference slip amount, target slip amount determining means for determining a target slip amount based on the reference slip amount, traction control judging means for outputting a traction control signal when a traction control is needed, target braking force calculating means, target engine torque calculating means. When a traction control is needed, the target slip amount determining means determine a target slip amount of a wheel needing the traction control.

Abstract: In a driving force control system for a vehicle, an angular velocity of the course direction of the vehicle body is calculated. On the other hand, a target angular velocity of the course direction is determined based on a steering angle and a vehicle speed. Then, based on the degree of the deviation of the calculated angular velocity from the target angular velocity, a correction coefficient for reducing an engine power is generated. When the vehicle traces off the course in the marginal condition on the low friction coefficient road, the correction coefficient reduces the engine power to prevent the vehicle from going out of the course.

Abstract: In a vehicle motion control system, a target rear-wheel steering-angle calculating section calculates a target rear-wheel steering angle, a rear-wheel steering-quantity setting section sets a rear-wheel steering quantity, and a rear-wheel steering signal output section outputs a rear-wheel steering quantity to a motor driving section to perform a steering angle control. In addition, a front-and-rear wheel steering response-parameter calculating section calculates a response parameter, and a front-and-rear wheel steering target yaw-rate calculating section calculates a target yaw rate. A yaw-rate difference calculating section calculates a yaw-rate difference, a target braking-force calculating section calculates a target braking force, and a braked-wheel discriminating section selects a wheel to be braked.

Abstract: In a torque distribution control system of a four wheel drive vehicle, it is important to distribute a driving force properly between front and rear wheels according to friction coefficient of road surface. Especially when a vehicle runs on roads with low friction coefficients of road surface, it is very important to estimate friction coefficients of the road surface which vary every moment and to control the driving force according to the estimated friction coefficients. The present invention provides the torque distribution control system with means for estimating friction coefficients of road surface every moment based on data from a steering angle sensor, a vehicle speed sensor and a yaw rate sensor and for reflecting them on the calculation of torque distribution between front and rear wheels. Furthermore, yaw moment calculating means are provided to prevent the vehicle from tack-in phenomenon by properly controlling left and right wheels.

Abstract: A traction control system for a fourwheel drive vehicle having a center differential comprises a brake pressure control apparatus, an engine output control apparatus, a differential limiting torque control apparatus, vehicle speed calculating means for calculating a reference vehicle speed of a vehicle, slip amount calculating means for calculating a slip amount of each wheel, target slip amount determining means for determining a front target slip amount of front wheels and a rear target slip amount of rear wheels, traction control determining means for determining to operate a traction control when the slip amount of the front wheels exceeds the front target slip amount or when the slip amount of the rear wheels exceeds the rear target slip amount, brake pressure calculating means for calculating a brake pressure so as to apply a brake to the wheels and engine output calculating means for calculating a target engine torque corresponding to a difference between the slip amount and the target slip amount, whe

Abstract: In a driving force control system for a vehicle, an angular velocity of the course direction of the vehicle body is calculated. On the other hand, a target angular velocity of the course direction is determined based on a steering angle and a vehicle speed. Then, based on the degree of the deviation of the calculated angular velocity from the target angular velocity, a correction coefficient for reducing an engine power is generated. When the vehicle traces off the course in the marginal condition on the low friction coefficient road, the correction coefficient reduces the engine power to prevent the vehicle from going out of the course.

Abstract: A vehicle speed calculation system capable of calculating a reference vehicle speed of a fourwheel drive vehicle with high accuracy when a fourwheel slip or lock occurs. An integrated value of a longitudinal acceleration is forcedly used for the calculation of the reference vehicle speed when the vehicle is accelerated and a variation of a lowest wheel speed is negative or when the vehicle is decelerated and a variation of a highest wheel speed is positive.

Abstract: A braking force control system and method of a vehicle comprises an estimated yaw rate calculating section for calculating an estimated yaw rate on a road surface having low friction coefficient, a target yaw rate differential calculating section for calculating a target yaw rate differential, an estimated yaw rate differential calculating section for calculating an estimated yaw rate differential, a yaw rate differential deviation calculating section for calculating a deviation of the both differentials, a first target braking force calculating section for calculating a first target braking force, a yaw rate deviation calculating section for calculating a deviation of an actual yaw rate and a target yaw rate, a second target braking force calculating section for calculating a second target braking force, a final target braking force calculating section for calculating a final target braking force based on the first and second target braking forces.

Abstract: An ideal lateral acceleration is calculated based on vehicle speed and steering angle, and an actual lateral acceleration is calculated based on a lateral acceleration detected by a lateral G sensor. A breakaway point of tires is determined by comparing the actual lateral acceleration with the ideal lateral acceleration. A differential operation of a central differential is controlled by restricting the differential operation in accordance with a determined breakaway point and the difference between the ideal lateral acceleration and the actual lateral acceleration.

Abstract: A lapping tape has an abrasive coat which comprises an acicular iron oxide powder having a surface area of at least 30 m.sup.2 /g as determined by the BET method and a granular inorganic powder having a Moh's hardness of more than 7 and contained in an amount of from 2.0 to 30 percent by weight on the basis of the weight of the oxide powder. The coat has a centerline mean roughness between 0.015 and 0.03 .mu.m. Preferably the acicular iron oxide is magnetic, and the inorganic powder ranges in particle diameter from 0.05 to 0.4 .mu.m.