Abstract: A vehicle chassis control stores first and second calibrated values of a predetermined braking parameter and a steering correction parameter. The control includes apparatus for detecting a split coefficient condition with respect to the road surface; and, when it does and a braking signal is present, the control actuates braking apparatus for a wheel on the side of the vehicle having the higher coefficient of friction with the first calibrated value of the predetermined braking parameter and simultaneously actuates the steering apparatus with a steering correction to compensate for yaw induced by braking on the split coefficient road surface. If the steering correction is not available, however, the braking apparatus is actuated for the wheel having the higher coefficient of friction with the second calibrated value of the predetermined braking parameter without simultaneously actuating the steering apparatus with the steering correction.

Abstract: The road surface friction sensor of this invention comprises means for measuring the strain of the tire or around the wheel of a vehicle. By using this sensor, a vehicle antilock braking device can be constructed which is adapted to cyclically increase the pressure of brake fluid while the road surface frictional force increases in response to elevation of brake fluid pressure, decrease the brake fluid pressure when the road surface frictional force declines despite elevation of brake fluid pressure and increase the brake fluid pressure again when the road surface frictional force has declined in response to fall-off of brake fluid pressure. The output signal from the above road surface friction sensor can be subjected to mathematical operation to find a road surface friction coefficient.

Abstract: In alarming apparatus and method for an automotive vehicle, a vehicular running state is detected, a frictional coefficient of a road surface on which the vehicle is running is detected, a vehicle using road surface frictional coefficient that corresponds to a road surface frictional force the presently running vehicle is using is calculated on the basis of the detected vehicular running state, a road surface frictional coefficient utilization rate is calculated which is a rate of the calculated vehicle using road surface frictional coefficient of the road surface to a maximum frictional coefficient detected by the road surface frictional coefficient detector, and an alarm controlling section is calculated to output an alarm command to an alarm device to issue an alarm when the calculated road surface frictional coefficient utilization rate is equal to or larger than a set value.

Abstract: A vehicle deceleration unit has a power train decelerator which controls a power train output to decelerate the vehicle and a brake device which presses a frictional member against a wheel or a rotational member rotating together with the wheel. Upon issuance of a demand for deceleration of the vehicle, the vehicle is decelerated by means of power train output control through the power train decelerator and brake control through the brake device. The vehicle deceleration unit has a target deceleration determiner for detecting a target deceleration, a turning state detector for detecting a turning state of the vehicle, and a control amount calculator for calculating a power train output control amount and a brake control amount based on the target deceleration and the turning state. The vehicle deceleration unit makes it possible to stably decelerate the vehicle regardless of a turning state of the vehicle.

Abstract: The braking effect in a vehicle is set in the sense of preventing a tendency to lock-up with at least two wheels which are arranged on at least one axle on the right and left and whose motion characteristics are detected. The braking effect on the two wheels is set jointly, with at least two operating modes (select low, select high) being provided; they can be selected depending on the coefficients of friction prevailing on the wheels and/or depending on the vehicle speed. An operating mode is selected according to the value of the prevailing coefficients of friction when there are coefficient of friction differences of a preselectable lower value. As an alternative or in addition, an operating mode is selected according to the detected vehicle speed when there are coefficient of friction differences of a preselectable greater value.

Abstract: A correction factor setting unit sets correction factors for a front-rear traction distribution control unit, an anti-lock brake control unit, a traction control unit, and a braking power control unit according to the situation of a road and the shape thereof which are inputted from a road information recognizing unit. At this time, the correction factors are preset values according to the situation of the road and the shape thereof so that the actions of the control units will be balanced with each other. Consequently, the plurality of vehicle behavior control units mounted in a vehicle act efficiently according to the situation of the road, on which the vehicle is driven forwards, and the shape thereof while quickly responding to the situation of the road and the shape thereof. Besides, the actions of the vehicle behavior control units are balanced with one another.

Abstract: An anti-lock brake control system 12 for a vehicle 10 that enhances vehicle braking when the vehicle is commanded to travel in a substantially straight trajectory. The brake control system 12 has an operator input 18 for commanding vehicle braking, and brake actuators 20A-20C for applying braking force to wheels 14A-14D in response to the operator input. In addition, the brake control system includes a steering angle sensor 34 for sensing a steering angle of the vehicle, and a wheel speed sensors 36 for sensing rotational speed of the wheels. Further, the brake control system 12 includes a controller 22 for controlling the amount of braking by the brake actuators 20A-20C in accordance with a tire slip as determined by the wheel speed. The controller 22 determines the amount of tire slip during braking and increases the amount of tire slip to increase vehicle braking when the vehicle 10 is commanded to travel in a substantially straightline trajectory.

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 vehicle running condition judgment device for accurately detecting a change in a road surface condition and a vehicle's limit running condition. With substitution of respective tire characteristics and a detected state quantity into a vehicle motion model, vehicle slip angles are estimated for respective assumed road surface conditions. Based on the current state quantity and the last estimated vehicle slip angle, currently estimated vehicle slip angles for the respective assumed road surface conditions are compensated. A differential operation section calculates an estimation value of a vehicle slip angular velocity for each of the assumed road surface conditions based on the compensated vehicle slip angles for the respective assumed road surface conditions. Meanwhile, an operation section calculates a detection value of a vehicle slip angular velocity based on the detected state quantity.

Abstract: A moving behavior control device for a vehicle calculates first target braking forces to be applied to the respective wheels for stabilizing the vehicle against a turn instability, second target braking forces to be applied to the respective wheels for stabilizing the vehicle against a roll instability, and target overall braking forces to be applied to the respective wheels by integrating the first and second target braking forces, and applies braking forces to the respective wheels according to the target overall braking forces, wherein the applied braking forces are decreased according to a first rate schedule by which the applied braking forces are decreased at a first rate according to an excess of the applied braking forces relative to the target overall braking forces when the vehicle is running at no probability of rolling beyond a predetermined threshold roll, and according to a second rate schedule by which the braking forces are lowered at a second rate smaller than the first rate according to the

Abstract: A vehicle braking system including a controller, in an initial anti-skid cycle, performs a first determination to select a high or a low control mode in accordance with wheel speed parameters. The controller in a second, or subsequent anti-skid cycle, performs a second determination to determine whether a near &mgr; test is to be performed in accordance with wheel speed parameters. The controller consequent upon selection of low control mode performs a near &mgr; test. The near &mgr; test includes performing a rise in the brake pressure and then selecting a high or low mode in accordance with the speed of the wheels resulting from the rise in brake pressure in the near &mgr; test.

Abstract: The coefficient of friction &mgr;s between the wheels of the vehicle and the road surface is identified as a function of the slip, and the maximum drive torque MAmax which can be transmitted is determined as a function of this slip-dependent coefficient of friction &lgr;. &lgr; is corrected when there is an increased slip requirement &lgr;erf as a result of the speed of the vehicle and/or the tire mixture used.

Abstract: A travel state of a vehicle is detected by a travel-state detecting device. A lateral slip angle of a vehicle body is calculated as a first lateral slip angle in a first lateral slip angle calculating device by integrating a differentiated value of lateral slip angle determined based on a non-linear four-wheel vehicle's motion model. A lateral slip angle of the vehicle body is calculated as a second lateral slip angle in a second lateral slip angle calculating device by a calculation in a linear two-wheel vehicle's motion model. One of the first and second lateral slip angles is selected alternatively in a selecting device in accordance with the travel state detected by the travel-state detecting device such that the second lateral slip angle is selected when the travel-state detecting device detects a state in which the vehicle is traveling straightforwardly at a low speed.

Abstract: An improved vehicle yaw control that does not require a yaw sensor, wherein the validity of an estimate of vehicle yaw is determined and used to select an appropriate control methodology. The vehicle yaw is estimated based on the measured speeds of the un-driven wheels of the vehicle, and various other conditions are utilized to determine if the estimated yaw rate is valid for control purposes. When it is determined that the estimated yaw rate is valid, a closed-loop yaw rate feedback control strategy is employed, whereas in conditions under which it is determined that the estimated yaw rate is not valid, a different control strategy, such as an open-loop feed-forward control of vehicle yaw, is employed. The validity of the estimated yaw rate is judged based on a logical analysis of the measured wheel speed information, braking information, and steering wheel angle. The measured speeds of the un-driven wheels are used to compute an average un-driven wheel speed and an average un-driven wheel acceleration.

Abstract: A system and method for vehicle dynamic control processes a compensated yaw rate signal measurement and a compensated lateral acceleration signal measurement (30, 32) to derive a signal measurement of road bank angle disturbance not compensated for in a compensated steering angle signal measurement and provides the derived signal to a controller (12). The compensated steering angle signal measurement is an input to the controller. Because a disturbance already compensated in the compensated steering angle signal measurement is transparent to the controller, the controller is able to adjust the control action of the vehicle dynamic control system based on the derived signal measurement of road bank angle disturbance not compensated for in a compensated steering angle signal measurement, thereby providing enhanced robustness of control.

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: An antiskid brake controller utilizes measured wheel speed in order to provide brake control for a vehicle such as an aircraft. The controller estimates the speed of the vehicle via approximation based on the measured wheel speed and a model of the mu-slip ratio curve representing the wheel to running surface friction characteristics. The controller then predicts the slip ratio based on the measured wheel speed and estimated vehicle speed. The difference between the predicted slip ratio and a predefined desired slip ratio is used to drive a modified integral controller segment to achieve maximum obtainable friction. In another embodiment, the controller measures and integrates the applied braking torque in order to estimate the vehicle speed. The estimated vehicle speed is again combined with the measured wheel speed to determine an estimated slip ratio. The controller compares the estimated slip ratio with a predefined desired slip ratio which again drives a modified integral controller.

Abstract: An anti-skid control system for an automotive vehicle, comprises a plurality of actuators each associated with one of front-left, front-right, rear-left and rear-right road wheels, for adjusting braking forces applied to the road wheels, sensors for detecting wheel speeds of the road wheels to generate wheel-speed indicative signals, and a controller for controlling the actuators in response to the wheel-speed indicative signals. The controller controls a hydraulic actuator associated with a controlled outer rear road wheel through a so-called select-LOW process between a wheel-speed indicative signal value of the controlled rear outer road wheel and a wheel-speed indicative signal value of a diagonal front wheel located on the vehicle diagonally to the controlled outer rear wheel only when the controller determines that the vehicle is in a cornering state with a high lateral acceleration during a braking-force control for the controlled outer rear wheel.

Abstract: A descending grade condition detecting system which can accurately detect a descending grade such as a snow-packed road or the like where slippage is likely determines whether permission has been granted to perform descending grade determination. If so, it determines whether established vehicle body deceleration is 0.3 G or less. If so, the system determines whether a road surface at each of the wheels is low .mu. corresponding to a snow-packed road or the like. If estimated vehicle body deceleration is small and of comparatively high .mu., descending grade condition flags KF are set for the respective wheels for which determination thereof has been made to indicate that a condition of a road being traveled is a condition of a low .mu. descending grade of a snow-packed road or the like.

Abstract: In order to correctly detect the frictional state of a running road surface, the running road surface is determined as a low-friction road surface, when tire lock is detected by tire lock detection device, and besides a state in which vehicle deceleration obtained by vehicle deceleration detection means is greater than a predetermined value, is shorter than a predetermined time in a period extending from the start of braking until the tire lock.

Abstract: Traction control for an internal combustion engine uses the gas pedal position, steering wheel position and velocity to set a wheel slip target during traction control operation.