Drive wheel traction control during vehicle stability enhancement events
First Claim
1. A method for controlling the traction on a drive surface of drive wheels of a motor vehicle having a vehicle stability enhancement system of the type becoming active when a vehicle yaw rate error is sensed for providing braking control of individual wheels of the motor vehicle to reduce the vehicle yaw rate error below a predetermined value, the method comprising the steps:
- deriving a target velocity from a vehicle longitudinal speed and one or more of a vehicle longitudinal acceleration, a vehicle lateral velocity and a vehicle turn curvature;
estimating a coefficient of friction between the vehicle wheels and the drive surface; and
responsive to activity of the vehicle stability enhancement system in reducing a vehicle yaw rate error, bounding the target velocity between a maximum target velocity value and a minimum target velocity value, at least one of the maximum target velocity value and the minimum target velocity value being derived from the estimated coefficient of friction.
2 Assignments
0 Petitions
Accused Products
Abstract
A traction control for a motor vehicle derives a target delta velocity as the sum of a longitudinal velocity of the vehicle and a target delta velocity derived from one or more of a longitudinal acceleration, a lateral acceleration and a turn curvature. The vehicle has a vehicle stability enhancement system of the type becoming active when a vehicle yaw rate error is sensed for providing braking control of individual wheels of the motor vehicle to reduce the vehicle yaw rate error below a predetermined value. In response to activity of the vehicle stability enhancement system in reducing a vehicle yaw rate error, the target delta velocity, and thus the target velocity, is bounding between a maximum target velocity value and a minimum target velocity value, at least one of which is derived from an estimated coefficient of friction between the vehicle drive wheels and the drive surface. The choice of which of the upper and lower bounds is to be so limited depends on whether the drive wheels are front wheels or rear wheels and whether the vehicle is in understeer or oversteer.
32 Citations
18 Claims
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1. A method for controlling the traction on a drive surface of drive wheels of a motor vehicle having a vehicle stability enhancement system of the type becoming active when a vehicle yaw rate error is sensed for providing braking control of individual wheels of the motor vehicle to reduce the vehicle yaw rate error below a predetermined value, the method comprising the steps:
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deriving a target velocity from a vehicle longitudinal speed and one or more of a vehicle longitudinal acceleration, a vehicle lateral velocity and a vehicle turn curvature;
estimating a coefficient of friction between the vehicle wheels and the drive surface; and
responsive to activity of the vehicle stability enhancement system in reducing a vehicle yaw rate error, bounding the target velocity between a maximum target velocity value and a minimum target velocity value, at least one of the maximum target velocity value and the minimum target velocity value being derived from the estimated coefficient of friction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A traction control for a motor vehicle having drive wheels and a vehicle stability enhancement system of the type becoming active when a vehicle yaw rate error is sensed for providing braking control of individual wheels of the motor vehicle to reduce the vehicle yaw rate error below a predetermined value, the traction control comprising:
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means for deriving a target velocity from a vehicle longitudinal speed and one or more of a vehicle longitudinal acceleration, a vehicle lateral velocity and a vehicle turn curvature;
means for estimating a coefficient of friction between the vehicle wheels and the drive surface; and
means responsive to activity of the vehicle stability enhancement system in reducing a vehicle yaw rate error for bounding the target velocity between a maximum target velocity value and a minimum target velocity value, at least one of the maximum value and the minimum value being derived from the estimated coefficient of friction. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification