US 2010/0059017 A1 · METHOD AND DEVICE FOR DETERMINING AN OPTIMIZED EMERGENCY RUNNING FUNCTION IN A FAULT-AFFLICTED ENGINE OF A MOTOR VEHICLE

Abstract

In a motor vehicle having an emergency running device, there is the problem that, in the event of certain fault symptoms occurring, an emergency running function is initiated and the torque of the engine is in the process limited to an unsuitable low value. In the worst case, this can lead to insufficient acceleration, for example during an overtaking maneuver, and to an accident occurring. It is therefore proposed that the determination of an optimized emergency running function be defined as a function both of the present driving state of the motor vehicle and also of the type of fault symptom depending on which the risk and the level of danger are graded into classes and an optimized emergency running function is then determined and initiated. Thus, sufficient torque and rotational speed can be provided for reliable vehicle control even in an unfavorable traffic situation without damaging the endangered components.

Claims20

Dependent claims

A method of determining an optimized limp-home function for an engine of a motor vehicle, the engine being designed with a device, by means of which in the event of at least one of a fault symptom the torque and the rotational speed of the engine is limited, the method comprising the steps of:

evaluating, on the basis of actual values of at least one of appropriate vehicle-data, engine data, and the previous trend thereof, the actual driving state of the motor vehicle,
determining, for the evaluated actual driving state of the motor vehicle, a classification of the criticality, in which at least one of a high torque and a high rotational speed is required,
evaluating, for a detected fault symptom of the engine or of one of the vehicle devices, a classification of the risk of damage occurring to at least one of the engine and to one of the vehicle devices at a high torque or a high rotational speed, and
while simultaneously taking the determined classifications of the criticality and the risk into account, determining an optimized limp-home function.

1 more element

Dependencies are inferred from the claim text.

Method and device for determining an optimized emergency running function in a fault-afflicted engine of a motor vehicle

Life of this patent

Method and device for determining an optimized emergency running function in a fault-afflicted engine of a motor vehicle

Life of this patent

Abstract

Claims20