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US 6,808,041 B2Granted
Method and system for providing secondary vehicle directional control through braking
AssigneeDelphi Technologies, Inc.
InventorJon D. Demerly
Life of this patent
Estimating the term…
Abstract
A method for implementing directional control of a motor vehicle is disclosed. In an exemplary embodiment, the method includes determining whether a failure of a primary steering system of the motor vehicle exists. If a failure of the primary steering system exists, then a yaw moment is created on the vehicle by causing a differential longitudinal force to be applied with respect to a first wheel on one side of the vehicle and a second wheel on an opposite side of the vehicle, thereby causing the vehicle to turn in a commanded direction.
Claims8
A method for implementing directional control of a motor vehicle, the method comprising:
- determining whether a failure of a primary steering system of the motor vehicle exists;
- if a failure of the primary steering system exists, then creating a yaw moment on the vehicle by causing a differential longitudinal force to be applied with respect to a first wheel on one side of the vehicle and a second wheel on an opposite side of the vehicle, thereby causing the vehicle to turn in a commanded direction;
- wherein said causing a differential longitudinal force further comprises applying a braking force to at least one of said first and second wheels of the vehicle;
- wherein said creating a yaw moment on the vehicle further comprises:
- determining a desired directional response,
- determining whether a desired braking operation exists, and
- generating a brake torque output signal, based upon said desired directional response and whether said desired braking operation exists, said brake torque output signal being used in said selectively applying a braking force;
- wherein said desired directional response is determined by a closed-loop yaw rate control mechanism, said closed-loop yaw rate control mechanism being implemented by:
- generating an error signal, said error signal representing the difference between a desired yaw rate and said vehicle yaw rate;
- and
- said desired yaw rate being determined from a steering wheel angle and a vehicle speed;
- wherein said desired yaw rate is further determined by:
- inputting said steering wheel angle and said vehicle speed into a lookup table, said lookup table thereby determining a desired steady state yaw rate;
- and
- filtering said desired steady state yaw rate through a second order filter.
12 more elements
A method for implementing directional control of a motor vehicle, the method comprising:
- determining whether a failure of a primary steering system of the motor vehicle exists;
- if a failure of the primary steering system exists, then creating a yaw moment on the vehicle by causing a differential longitudinal force to be applied with respect to a first wheel on one side of the vehicle and a second wheel on an opposite side of the vehicle, thereby causing the vehicle to turn in a commanded direction, wherein said causing a differential longitudinal force further comprises applying a braking force to at least one of said first and second wheels of the vehicle;
- wherein said creating a yaw moment on the vehicle further comprises:
- determining a desired directional response,
- determining whether a desired braking operation exists, and
- generating a brake torque output signal, based upon said desired directional response and whether said desired braking operation exists, said brake torque output signal being used in said selectively applying a braking force;
- wherein said desired directional response is determined by a closed-loop yaw rate control mechanism, said closed-loop yaw rate control mechanism being implemented by:
- generating an error signal, said error signal representing the difference between a desired yaw rate and said vehicle yaw rate;
- and
- said desired yaw rate being determined from a steering wheel angle and a vehicle speed;
- and
- using a feedforward term to generate an initial brake input component to said braking force, said feedforward term being a function of said vehicle speed.
9 more elements
A method for implementing directional control of a motor vehicle, the method comprising:
- determining whether a failure of a primary steering system of the motor vehicle exists;
- if a failure of the primary steering system exists, then creating a yaw moment on the vehicle by causing a differential longitudinal force to be applied with respect to a first wheel on one side of the vehicle and a second wheel on an opposite side of the vehicle, thereby causing the vehicle to turn in a commanded direction, wherein said causing a differential longitudinal force further comprises applying a braking force to at least one of said first and second wheels of the vehicle;
- wherein said creating a yaw moment on the vehicle further comprises:
- determining a desired directional response,
- determining whether a desired braking operation exists, and
- generating a brake torque output signal, based upon said desired directional response and whether said desired braking operation exists, said brake torque output signal being used in said selectively applying a braking force;
- configuring a switching mechanism for selectively switching between a first, a second and a third mode of operation;
- said first mode of operation corresponding to an operational status of the primary steering system;
- said second mode of operation corresponding to a failure of the primary steering system and a commanded directional control operation of the motor vehicle;
- said third mode of operation corresponding to a failure of the primary steering system and a combined directional control operation and a braking operation of the motor vehicle;
- and
- wherein said brake torque output signal is dependent upon which of said first, second and third modes of operation is selected by said switching mechanism.
9 more elements
Dependencies are inferred from the claim text.