摘要:
A correlation coefficient computing unit receives front-left and front-right wheel-accelerations from high-pass filters, each having a driver-operating component removed therefrom, and computes a correlation coefficient therebetween. A computing-unit of upper and lower limits of a correlation coefficient of a population sets upper and lower limits of a correlation coefficient of a population. First and second correction-gain setting units set first and second correction-gains varying in accordance with running and driving states, respectively. A correlation coefficient computing unit of a population computes a correlation coefficient of a population of this time based on the correlation coefficients computed as above, a correlation coefficient of a population of the previous time, the upper and lower limits, and the first and second correction-gains. A coefficient of friction on road surface estimating unit estimates a coefficient of friction on road surface by comparing the correlation coefficient of the population of this time with a determining threshold value previously set according to the running state.
摘要:
To provide a new vehicle control technique, a calculation section calculates a cornering power ka using the detected longitudinal force Fx, lateral force Fy, and vertical force Fz, and the identified friction coefficient μ. This calculation is made based on the correlation between a slip angle β of the wheels and the lateral force Fy. Based on thus calculated cornering power ka and a target cornering power ka′ required for the wheels, a processing section determines a change amount for changing at least one action force out of the longitudinal force Fx, the lateral force Fy, and the vertical force Fz, all acting on the wheels. Based on thus determined change amount, a control section controls at least one action force out of the longitudinal force Fx, the lateral force Fy, and the vertical force Fz, all acting on the wheels.
摘要:
A vehicle behavior control apparatus is divided into three major parts, sensors for detecting engine and vehicle operating conditions, a target yaw rate establishing section for establishing the rate and differential limiting apparatuses for selectively varying distribution ratios of driving force between front and rear wheels and/or between left and right wheels. The target yaw rate establishing section calculates a target yaw rate based on a vehicle mass, a mass distribution ratio between front and rear axles, front and rear axle mass, distances between front and rear axles and a center of gravity, a steering angle of a front wheel, and front and rear wheels equivalent cornering powers. A steady state yaw rate gain is separately calculated for left and right steering, respectively. A reference yaw rate is calculated by correcting a time constant of lag of yaw rate with respect to steering based on estimated road friction coefficient.
摘要:
A vehicle front-view monitoring system determines whether there is a fail occurring on the monitoring system based on luminance data on an image of a front view taken by camera and takes fail-safe measures if the fail is occurring. The luminance data indicates luminance-distribution characteristic values indicating horizontal luminance-distribution on the image. A fail can be determined based on a parameter obtained by normalizing the luminance-distribution characteristic values by a shutter speed for the camera equipment.
摘要:
A vehicle front-view monitoring system takes fail-safe measures when a fail-safe measure-interruption requirement using first parameter are met on a monitored image for a predetermined first period. The functions interrupted by the fail-safe measure is resumed when a fail-safe measure-release requirement using second parameter which is different from the first parameter is met within a predetermined second period after the fail-safe measure-interruption requirement has been met. The first period is variable in accordance with how accurately lane marking on a road in the monitored image is recognized.
摘要:
A road friction coefficient estimating apparatus primarily includes an adaptive control road friction coefficient estimating section and an actual value comparison road friction coefficient estimating section. The adaptive control road friction coefficient estimating section inputs signals indicative of a road surface condition with low friction coefficient from a wiper switch, low outside air temperature judging section and the like and estimates an accurate road friction coefficient even under the low friction coefficient road surface condition. When the vehicle travels at high speeds, the actual value comparison road friction coefficient estimating section renders a road friction coefficient estimating value by a yaw rate comparison method gradually close to a road friction coefficient of an asphalted road surface. When a signal IMAGE HALT indicative of a road surface totally covered with snow is inputted, the actual value comparison road friction coefficient estimating section renders the road friction coefficient estimating value gradually close to a low side road friction coefficient produced by the adaptive control road friction coefficient estimating section. Further, when the vehicle travels at high speeds and the signal IMAGE HALT is inputted, the road friction coefficient estimating value is rendered moderately, gradually close to the low side road friction coefficient.
摘要:
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.
摘要:
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. In addition, the system may further comprise an output discriminating section for comparing the difference in yaw rate with a discriminating threshold to discriminate as to whether the difference in yaw rate is within a control region. A first threshold is set as the discriminating threshold. After the under-steering tendency is changed to the over-steering tendency, a set period of time and a second threshold, the absolute value of which is smaller than that of the first threshold, are set. With this construction, it is possible to smoothly perform the control without giving uncomfortable feeling to a driver, and it is also possible to restrain the control by a rear wheel.
摘要:
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. The target braking force calculating means produce a braking force according to the difference between the target slip amount and the actual slip amount and brake is automatically applied to a wheel requiring the traction control through the brake drive apparatus. At the same time, the target engine torque calculating means produce a signal to the engine control apparatus so as to reduce engine torque.
摘要:
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. When an output discriminating section determines that there is within a controllable region, a braking signal output section outputs a signal to a brake driving section so as to add the target braking force to the selected wheel.