Abstract:
A plurality of vehicle stabilizing devices which operate according to different strategies and which actuate, independently of the driver, brake actuators which are assigned to the vehicle wheels, in order to stabilize the vehicle are arranged in the vehicle. The vehicle is equipped with at least one switchable differential lock in the drive train. The differential lock assumes a non-switched operating state, a first operating state in which the differential lock is preselected, and a second operating state in which the differential lock is switched. When the differential lock assumes the first operating state, some of the vehicle stabilizing devices, other than that vehicle stabilizing device which, by actuating the brake actuators independently of the driver, prevents the vehicle wheels from locking during a braking operation, are influenced in terms of their operating mode. When the differential lock assumes the second operating state, all the vehicle stabilizing devices are influenced in their operating mode. The operating mode of the vehicle stabilizing devices is influenced in such a way that the actuation of the brake actuators which is independent of the driver does not occur.
Abstract:
An anti-lock braking and traction control system includes a sources of pressurized fluid, an actuator adapted to selectively supply the pressurized fluid to wheel brakes and a clutch. A controller communicates with the actuator to control the duration of magnitude of pressure supplied to the wheel brakes and the clutch.
Abstract:
A method is directed to controlling a traction control system including a controllable center coupling and a controlled brake system. The method provides for receiving axle speed information, receiving a vehicle speed, determining at least one difference value between the vehicle speed and the axle speed information, and activating the controllable center coupling and the controlled brake system responsive to the difference values. The step of activating the controllable center coupling responsive to at least one of the difference values may include comparing the at least one difference value to at least one associated threshold value, and activating the controllable center coupling based on the comparison. The step of activating the controllable center coupling based on the comparison may include determining an engine torque request value based on the comparison, and engaging an engine with the controllable center coupling based on the engine torque request value.
Abstract:
The differential limiting control apparatus having a clutch unit interposed between one rotational shaft and the other rotational shaft for variably transmitting a driving force between the one rotational shaft and the other rotational shaft, having: a feedback control unit for computing the clutch torque on basis of vehicle behaviors through a feedback control, a feed forward control unit for computing the clutch torque based on the behaviors through feed forward control, a tire diameter difference computing unit for computing a diameter difference of a tire, and a clutch torque computing unit for computing a final clutch torque by changing a ratio of the clutch torque obtained through the feedback control and a clutch torque obtained through the feed forward control so as to appropriately decide the feed forward control by effectively suppress the tire slip while avoiding the occurrence of the internal circulation of the torque.
Abstract:
In a vehicle dynamics control (VDC) system for a four-wheel-drive vehicle employing a brake control system regulating braking forces applied to road wheels independently of each other and a differential mechanism controlling a differential motion between front and rear wheel axles, a VDC controller controls a braking force of each road wheel depending on whether the vehicle is in oversteering or understeering. The VDC controller includes a braking-force compensation section that compensates for a braking force of at least one of a first wheel, which is subjected to vehicle dynamics control, and a second wheel to which a transferred braking force is transferred from the first wheel through the differential mechanism, to reduce a braking force of the second wheel and to prevent the braking force of the second wheel from exceeding a lateral grip limit of the second wheel during the vehicle dynamics control.
Abstract:
A vehicle includes multiple wheels, a locking drive differential, and a stability controller. A first wheel is mechanically coupled to a second wheel. The locking drive differential mechanically couples the second wheel to a third wheel. The stability controller is coupled to the third wheel. The stability controller is programmed to attain a slip rate of about the first and the second wheel at the third wheel, which stabilizes the vehicle in an over-steer condition. The method applies a modulated stability pressure to the third wheel until the third wheel attains about the combined slip rate of the first wheel and the second wheel and a fourth wheel is rotating at about the velocity of the vehicle.
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 rearwheels 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 vehicle in which an engine output power is transmitted to front and rear wheels through a transmission and an inter axle differential, a wheel lock prevention device is provided. The wheel lock prevention device comprises a differential lock mechanism for locking the inter axle differential, a detection element for detecting a wheel lock state of the front and rear wheels, and an operation element for operating the differential lock mechanism so as to lock the inter axle differential by operating the differential lock mechanism upon the detection of the wheel lock state.
Abstract:
A method for controlling processes in a motor vehicle is intended, for example, for open-loop/closed-loop control of combustion processes, transmission switching processes or braking processes. An engine characteristics map is formed by operating quantities of the respective process and is represented by a number of support points. In the corresponding control unit, for each support point a piece of information about the value of the map at the position of the support point is provided. In the open-loop/closed-loop control of the process, for a determined working point of the process at least one map value that is decisive for this working point is determined from the map and taking account of this, at least one control quantity for the emission of a control signal is formed. The map is automatically adapted to a changed process behavior. For the adaptation, a correction value is determined for a certain operating phase of the map. According to the present invention, additionally for each support point a piece of information about the position of the support point within the map is provided so that the support points are enterable independent of a fixed grid into the map. For adaptation of the map, a number of support points of the map lying around the determined correction value is chosen. These support points are then adapted, the support point correction being carried out distance-weighted with reference to the position of the determined correction value within the map.
Abstract:
In a vehicle having a pair of right and left front wheels and a pair of right and left rear wheels, when the front wheels are driven wheels, a differential limiting mechanism such as a multi-disc viscous clutch is arranged between axle members coupled to axles of the front wheels via universal joints, or when the rear wheels are driven wheels, the differential limiting mechanism is arranged between axles of the rear wheels. The differential limiting force of the differential limiting mechanism is controlled on the basis of various physical quantities (a steering angle .theta.h, a vehicle speed V, a brake hydraulic pressure P, a vertical acceleration G, and a road-surface .mu.) associated with the traveling state of the vehicle detected by sensors. Therefore, there can be provided a driven wheel differential limiting apparatus for a vehicle, which has high reliability and durability since the differential limiting force is controlled via, e.g., the viscous force of a fluid, and which can assure quick-turn traveling performance at a low vehicle speed, and can improve straight traveling stability in a high-speed traveling state since the degree of differential limiting is varied in correspondence with the traveling state of the vehicle.