Abstract:
In order to adapt a simplified vehicle model to the driving behavior of a real automotive vehicle, it is possible to modify the slip rigidity values assumed to be constant in a linear model. After departure from the linear range of the lateral-force/slip-angle characteristic, a lower value can be assumed for the slip rigidities. However, this will involve the risk that the wheels of the rear axle are already in a slip angle range to which the lower slip rigidity is associated whereas the front wheels are still in the linear range of the lateral-force/slip-angle characteristic. This would impart to the vehicle model an oversteering behavior which should the more so be avoided if such a vehicle model is used for presetting the nominal value. This problem is solved, in the practice of the invention, by suggesting to modify only the slip rigidity values of the front axle while the ones of the rear axle are assumed to be constant.
Abstract:
Apparatus for improving the driving behavior of a vehicle is provided. The vehicle has front and rear axles, each having a plurality of wheels. Each wheel-has a brake. Sensor are provided for measuring the rotational speed of each wheel, the vehicle yaw rate and the vehicle lateral acceleration. An anti-lock braking system provides first preset pressure values for controlling each brake, to prevent the wheels from locking during braking. A traction slip control system provides second preset pressure values for controlling each brake, to prevent the wheels from slipping during acceleration. A brake effort proportioning system provides third preset pressure values for distributing braking pressure between the wheels of the front axle and the wheels of the rear axle. A yawing moment controller provides fourth preset pressure values used to control each brake during cornering, to avoid application to the vehicle of an unbalanced moment which would cause the vehicle to understeer or oversteer. The antilock braking system, traction slip control system, brake effort proportioning means and yawing moment control system all operate independently of one another. A prioritizing mechanism applies criteria to determine a desired brake pressure that is applied to each wheel, based on the outputs of the antilack braking, traction slip control, brake effort proportioning, and yawing moment control systems.
Abstract:
Apparatus for improving the driving behavior of a vehicle is provided. The vehicle has front and rear axles, each having a plurality of wheels. Each wheel has a brake. Sensor are provided for measuring the rotational speed of each wheel, the vehicle yaw rate and the vehicle lateral acceleration. An anti-lock braking system provides first preset pressure values for controlling each brake, to prevent the wheels from locking during braking. A traction slip control system provides second preset pressure values for controlling each brake, to prevent the wheels from slipping during acceleration. A brake effort proportioning system provides third preset pressure values for distributing braking pressure between the wheels of the front axle and the wheels of the rear axle. A yawing moment controller provides fourth preset pressure values used to control each brake during cornering, to avoid application to the vehicle of an unbalanced moment which would cause the vehicle to understeer or oversteer. The antilock braking system, traction slip control system, brake effort proportioning means and yawing moment control system all operate independently of one another. A prioritizing mechanism applies criteria to determine a desired brake pressure that is applied to each wheel, based on the outputs of the antilock braking, traction slip control, brake effort proportioning, and yawing moment control systems.
Abstract:
Yaw moment control apparatus is provided for improving the driving behavior of an automotive vehicle tending to oversteering or understeering. The vehicle's velocity, steering angle, measured yaw rate, and lateral acceleration are determined. A yaw controller generates a value representing a desired yaw rate adjustment based on the steering angle, the velocity and the measured yaw rate. An estimated coefficient of friction is calculated based on the vehicle velocity, the lateral acceleration, the measured yaw rate and the steering angle. The estimated coefficent of friction is used by the yaw controller to determined the desired yaw rate adjustment. The mechanism for calculating the estimated coefficient of friction is only enabled while the vehicle is traveling through a curve.
Abstract:
A process for controlling the driving stability of a vehicle is provided. To avoid complicated models for determining the desired value of a variable characteristic of the travel behavior, which variable usually must be calculated by an expensive calculation circuit, a controlled variable is selected, which directly describes the driving stability and is compared with an actual value, which can be calculated in a relatively simple manner. An advantageous embodiment describes comparing an actual value of the variable, which can be determined in a simple manner, with a desired value. The range of tolerance of the variable is set directly by the driving stability limits. Advantageous variants pertain to the suitable scheme of calculation and the selection of a suitable range of tolerance.
Abstract:
A vehicle sensor device, which includes at least one sensor for detecting the yaw rate of a vehicle, at least one sensor for detecting the lateral acceleration of a vehicle, at least one computing unit and at least one interface of a data bus, especially CAN or FlexRay, via which the sensor signals or sensor data derived therefrom can be transmitted to at least one electronic control device. According to an aspect of the invention, a steering angle sensor is integrated with the other sensors in a housing, and the computing unit carries out plausibility checking and/or calibration of the yaw rate signals and/or the lateral acceleration signals and/or the steering angle signals.
Abstract:
A method for a Sensitive Electronic Stability Program (SESP) presents a general approach for the correction of maneuvers of turning into a bend at low speed. It integrates existing methods as well as subsequent extensions. SESP supplements the standard active yaw control (AYC) function. This allows the SESP to use variables and mechanisms of AYC, on the one hand. On the other hand, AYC continues operating unimpeded in the background and will intervene as usual when SESP cannot stabilize the vehicle appropriately. When the standard AYC intervenes, SESP control operations are forbidden, or running SESP control operations are stopped. This stop can take place either abruptly or (which is more comfortable) by way of a moderate decrease of the correcting variables.
Abstract:
The present invention relates to a method for modifying a driving stability control of a vehicle wherein the input variables essentially composed of the predetermined steering angle (δ) and the driving speed (v) are converted into a nominal value of the yaw velocity ({dot over (Ψ)}nominal) on the basis of a vehicle model defined by running characteristics. The nominal value is compared with a measured actual value of the yaw velocity ({dot over (Ψ)}measured), and an additional yaw torque (MG) is calculated in an ESP controller according to the result of the comparison and used to define an ESP intervention which produces an additional yaw torque by way of pressure quantities applied to the wheel brakes of the vehicle.
Abstract:
A method of ensuring stability and good quality of yaw torque control even in the case of road surface transversal inclination and/or a rolling motion of the vehicle requires a transversal inclination identification. This is done by calculating the transversal inclination angle .alpha..sub.q, When a transversal inclination is identified, the calculating device of the vehicle can be set to counteract the transversal inclination vigorously. Calculation of the transversal inclination angle .alpha..sub.q is based on a coordinate transformation. The value a.sub.qm measured by the transverse accelerometer fixed to the vehicle is related to a value a.sub.q of the ground-related transverse acceleration calculated from other sensor signals pursuant the equationa.sub.qm =a.sub.q cos .alpha..sub.q -g sin .alpha..sub.q.The solution of this equation provides the transversal inclination angle .alpha..sub.q.
Abstract:
Disclosed is a method for controlling a process according to which an actuation parameter is produced depending on a control deviation that is determined by comparing a nominal value with an actual value of a control variable. The method is characterized in that the actual value of the control variable is determined based on a first process model and a need for control (10) is additionally verified by determining control requirements (20, 30, 40) by way of values of the control variable, which are identified by additional process models and associated with each other by means of logical operations.