Abstract: An estimating unit 7 estimates an element aij of a system matrix based on state quantity including at least a longitudinal force Fx applied to a wheel, a vertical force Fz applied to the wheel and a vehicle speed V. A setting unit 8 sets a target value aij? regarding the element aij of the system matrix. A processing unit 9 calculates a control value so that the estimated element aij approaches the set target value aij?. Controlling units 10 to 13 control a vehicle based on the calculated control value. Here, the element aij is expressed by a sum of a linear term changing with linearity of the wheel and a nonlinear term changing with nonlinearity of the wheel, and the setting unit 8 sets the linear term of the element aij as the target value aij?.

Abstract: A drive power from an engine is transferred to front wheel drive systems and rear wheel drive systems via a central differential. A torque distribution ratio between front and rear wheels defined by the central differential is set to one for the front wheels being made too much thereof, with a motor generator being coupled to the rear wheel drive systems. In response to detection signals from various sensors for detecting the running conditions, a drive power control unit controls the additional torque from the motor generator toward the drive torque or regenerative braking torque side, thereby changing the torque distribution ratio between the front and rear wheels. Thus, a degree of flexibility in making a change in the torque distribution between front and rear wheels or between right and left wheels is increased, thereby realizing an all-wheel drivable hybrid vehicle which provides further improved running performance.

Abstract: An estimating unit 7 estimates an element aij of a system matrix based on state quantity including at least a longitudinal force Fx applied to a wheel, a vertical force Fz applied to the wheel and a vehicle speed V. A setting unit 8 sets a target value aij? regarding the element aij of the system matrix. A processing unit 9 calculates a control value so that the estimated element aij approaches the set target value aij?. Controlling units 10 to 13 control a vehicle based on the calculated control value. Here, the element aij is expressed by a sum of a linear term changing with linearity of the wheel and a nonlinear term changing with nonlinearity of the wheel, and the setting unit 8 sets the linear term of the element aij as the target value aij?.

Abstract: In a differential limiting torque control section, a target differential rotation speed between front and rear drive shafts is established according to a dial position inputted by a driver of a variable dial. Further, an actual differential rotation speed between front and rear drive shafts is calculated and a deviation between the target differential rotation speed and the actual differential rotation speed is calculated. Based on the deviation, a first differential limiting torque and based on a dial position of a variable dial a second differential limiting torque are calculated. Further, a third differential limiting torque is calculated based on the dial position and a throttle opening angle. A final differential limiting torque between front and rear drive shafts is obtained by summing up these first, second and third differential limiting torques.

Abstract: A transfer clutch control units operates a second transfer clutch torque corresponding to a yaw moment out of the transfer clutch torque to be output to a transfer clutch drive unit by a second transfer clutch torque operational unit. The second transfer clutch torque operational unit operates a reference lateral acceleration from a lateral acceleration to be operated based on a linear vehicle motion model from a vehicle driving state and a preset coefficient according to the vehicle driving state, in addition to the yaw moment sensing the yaw rate and the yaw moment sensing the steering wheel angle, and operate the yaw moment corresponding to the deviation between the reference lateral acceleration and the actual lateral acceleration as a corrected value of the yaw moment. Not only a high ? road but also a low ? road, even abrupt change of road surfaces or the like can be consistently and optimally coped with in excellent response.

Abstract: A center differential limiting control unit calculates and sets a vehicle speed, a target difference in a rotational speed between front and rear axle shafts, a control start difference in the rotational speed, and an actual difference in the rotational speed, respectively. Then, when the actual difference is large than the control start difference, it is determined that a front and rear axle shaft control start condition is established, and front and rear axle shaft differential limiting torque is calculated according to the actual difference and the target difference. In contrast, when the actual difference is smaller than the control start difference, it is determined that the front and rear axle shaft control start condition is not established, and an integral term in the front and rear axle shaft limiting torque and control is set to 0.

Abstract: Steering stability of a vehicle under a traveling state such as cornering is enhanced by controlling a state of the vehicle based on cornering powers of right and left wheels. A detecting unit 1 detects action force containing longitudinal force Fx, lateral force Fy and vertical force Fz which act on each wheel. A specifying unit 2 specifies a friction coefficient between the wheels and road surface. An estimating unit 6 estimates cornering power ka of each wheel based on the action force and the friction coefficient. A processing unit 7 determines control values so that the representative value ka_ave of the cornering powers concerning the right and left wheels is larger than the present value of the representative value ka_ave of the cornering powers concerning the right and left wheels. Controlling units 8 to 10 control the state of the vehicle based on the control values thus determined.

Abstract: 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.

Abstract: A control apparatus for four wheel drive vehicle having differential limiting unit has: turning state determining unit; actual left and right wheel differential speed calculating unit; target differential speed setting unit; differential limiting torque calculating unit for setting a differential limiting torque at 0 in the event that an inside wheel speed falls below an outside wheel speed by a preset threshold value in the turning condition, and calculating a differential limiting torque on the basis of the target left and right wheel differential speed and the actual left and right wheel differential speed in the event that an inside wheel speed exceeds an outside wheel speed by the preset threshold value in the turning condition; and front and rear wheel differential limiting torque setting unit for setting a front and rear wheel differential limiting torque on the basis of a differential limiting torque which is calculated.

Abstract: 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 &mgr;. This calculation is made based on the correlation between a slip angle &bgr; 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.

Abstract: A mode establishing section of a differential limiting control apparatus for a four wheel drive vehicle commands an automatic mode control section or a manual mode control section to output calculated clutch torques according to a signal from a mode switch operated by a driver. In an initial condition of an ignition switch turned on, the execution command is issued to the automatic mode control section, until the driver newly selects the manual mode through the mode switch. Further, when the vehicle travels at a speed higher than a preestablished threshold value, the execution command is outputted to the automatic mode control section, irrespective of the signal from the mode switch.

Abstract: A center differential limiting control unit calculates and sets a vehicle speed, a target difference in a rotational speed between front and rear axle shafts, a control start difference in the rotational speed, and an actual difference in the rotational speed, respectively. Then, when the actual difference is large than the control start difference, it is determined that a front and rear axle shaft control start condition is established, and front and rear axle shaft differential limiting torque is calculated according to the actual difference and the target difference. In contrast, when the actual difference is smaller than the control start difference, it is determined that the front and rear axle shaft control start condition is not established, and an integral term in the front and rear axle shaft limiting torque and control is set to 0.

Abstract: A temporary indicated torque is obtained by taking a conventional dead zone area for a first slip control area, and the value proportional to the slip quantity for a maximum value, this temporary indicated torque is corrected by a correction value according to the tight cornering brake quantity to be the indicated torque of the transfer clutch, and occurrence of any tight cornering brake phenomenon is prevented thereby. In a slip control area after passing a dead zone area (a second slip control area), the slip control is smoothly transferred from the first slip control area to the second slip control area by performing the slip control with a value of the indicated torque according to the slip quantity added to the indicated torque in the first slip control area as the indicated torque, abrupt torque change is prevented, and the vehicle behavior is stabilized thereby.

Abstract: 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.

Abstract: In a differential limiting torque control section, a target differential rotation speed between front and rear drive shafts is established according to a dial position inputted by a driver of a variable dial. Further, an actual differential rotation speed between front and rear drive shafts is calculated and a deviation between the target differential rotation speed and the actual differential rotation speed is calculated. Based on the deviation, a first differential limiting torque and based on a dial position of a variable dial a second differential limiting torque are calculated. Further, a third differential limiting torque is calculated based on the dial position and a throttle opening angle. A final differential limiting torque between front and rear drive shafts is obtained by summing up these first, second and third differential limiting torques.

Abstract: A control apparatus for four wheel drive vehicle having differential limiting unit has: turning state determining unit; actual left and right wheel differential speed calculating unit; target differential speed setting unit; differential limiting torque calculating unit for setting a differential limiting torque at 0 in the event that an inside wheel speed falls below an outside wheel speed by a preset threshold value in the turning condition, and calculating a differential limiting torque on the basis of the target left and right wheel differential speed and the actual left and right wheel differential speed in the event that an inside wheel speed exceeds an outside wheel speed by the preset threshold value in the turning condition; and front and rear wheel differential limiting torque setting unit for setting a front and rear wheel differential limiting torque on the basis of a differential limiting torque which is calculated.

Abstract: A motion control system controls a vehicle so as to avoid contacting an obstacle in front of the vehicle by applying a braking force or a turning force to the vehicle. In particular, the turning force is applied to the vehicle to avoid the obstacle by turning the vehicle when the system judges that the vehicle can not avoid contact with the obstacle with deceleration presently applied. The turning force is calculated by comparing a first turning force necessary to make a turn to avoid the obstacle with a second turning force presently applied to the vehicle. The system generates the turning force presently applied to the vehicle. The system generates the turning force by controlling at least one of a braking force of a selected wheel, a front wheel steering mechanism and a rear wheel steering mechanism.

Abstract: A slip angle calculating unit calculates a slip angle of a vehicle body corresponding to a steering wheel angle and a vehicle speed, based on a vehicle wheel angle and the vehicle speed, by an observer of a preset vehicle motion model under a motion equation of a vehicle. A front wheel slip angle calculating unit calculates a front wheel slip angle based on the steering wheel angle, a vehicle speed, a yaw rate, and the calculated vehicle body slip angle. A self-aligning torque calculating unit calculates the self-aligning torque based on the hydraulic chamber pressure of the left side and the hydraulic chamber pressure of the right side in a power cylinder. The vehicle speed, an estimated front wheel slip angle, and the self-aligning torque are inputted to a road friction coefficient setting unit, and the road friction coefficient setting unit sets a road friction coefficient by referring to a map based on the input to output the set value.

Abstract: A control section of a road friction coefficient estimating apparatus inputs a vehicle speed, a steering wheel angle and a yaw rate from a vehicle speed sensor, a steering wheel angle sensor and a yaw rate sensor, respectively. The control section comprises a reference yaw rate calculating section, a yaw rate deviation calculating section, a yaw rate deviation dispersion calculating section and a road friction coefficient establishing section. The reference yaw rate calculating section calculates a reference yaw rate based on vehicle speed and steering angle in accordance with a vehicle motion model. The yaw rate deviation calculating section calculates a yaw rate deviation based on the reference yaw rate and the actual yaw rate. The yaw rate deviation dispersion calculating section calculates a dispersion of the yaw rate deviation for a specified sampling number.

Abstract: A correction coefficient setting unit calculates as a difference in an actual revolution speed the difference between the actual revolution speed of a front driving axle and the actual revolution speed of a rear driving axle. Moreover, the correction coefficient setting unit calculates the ideal reference revolution speed of the front driving axle and the ideal reference revolution speed of the rear driving axle in consideration of a difference in a radius of gyration between the driving axles. The correction coefficient setting unit also calculates as a difference in a reference revolution speed the difference between the ideal reference revolution speed of the front driving axle and the ideal reference revolution speed of the rear driving axle.