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US 11,685,367 B2Granted
System and method for reducing vehicle turning radius
AssigneeFord Global Technologies, LLC
InventorsKevin Sallee, Michael Edward Brewer
Life of this patent
Estimating the term…
Abstract
A method of providing automated application of turn radius reduction in a driver assist mode may include receiving steering wheel angle and wheel speed information to determine a target wheel slip during a turn. The method may further include comparing the target wheel slip to a current wheel slip to determine a slip error, and applying braking torque to an inside wheel based on the slip error to reduce the turn radius.
Claims12
A vehicle control system for reducing turn radius of a vehicle, the system comprising:
- a controller operably coupled to components and/or sensors of the vehicle to receive information including vehicle wheel speed and steering wheel angle, the controller being configured to determine a target wheel slip for a turn based on the information;
- and
- a torque control module configured to compare the target wheel slip to a current wheel slip and control application of braking torque to an inside wheel during the turn to reduce the turn radius based on a difference between the current wheel slip and the target wheel slip;
- wherein the controller is configured to control vehicle operation in any of a plurality of operator selectable modes of operation,
- wherein the torque control module is configured to apply the braking torque during the turn responsive to operator selection of a corresponding one of the modes of operation and detection of a trigger event,
- wherein the trigger event comprises detecting the steering wheel angle being within a first range of steering wheel angles, the first range of steering wheel angles extending from a starting angle to a maximum angle that corresponds to a limit of rotation of the steering wheel, and detecting vehicle speed within a range of enabling speeds,
- wherein the controller is configured to determine a state of a differential of the vehicle during the turn,
- wherein the applying the braking torque is enabled or disabled based on the state of the differential,
- wherein determining the state of the differential is performed over a second range of steering wheel angles, the second range of steering wheel angles less than the starting angle.
6 more elements
A torque control module of a vehicle control system, the torque control module comprising:
- a braking table configured to define a braking torque to be applied to a braking system based on a slip error defining a difference between a target wheel slip and a current wheel slip measured during a turn;
- and
- processing circuitry configured to compare the target slip to the current slip to define the slip error, and to control application of the braking torque to an inside wheel during the turn to reduce a turn radius of the vehicle based on the slip error;
- wherein the braking torque is applied as a step function, a ramp function, or a combination of the step function and the ramp function;
- wherein ramp rates defining rising versus falling ramps for the application of the braking torque are individually calibratable.
2 more elements
A method of providing automated application of turn radius reduction in a driver assist mode, the method comprising:
- receiving steering wheel angle and wheel speed information to determine a target wheel slip during a turn;
- comparing the target wheel slip to a current wheel slip to determine a slip error;
- and
- applying braking torque to an inside wheel based on the slip error to reduce the turn radius;
- wherein the method further comprises an initial operation of determining a predicted inside wheel speed for a turn based on a steering wheel angle and determining a state of a differential of the vehicle by comparing the predicted outside wheel speed to actual outside wheel speed,
- wherein the applying the braking torque is only enabled to be applied if the state of the differential is disengaged,
- wherein applying the braking torque is further only enabled over a first range of steering wheel angles, the first range of steering wheel angles extending from a starting angle to a maximum angle that corresponds to a limit of rotation of the steering wheel, and
- wherein determining the state of the differential is performed over a second range of steering wheel angles, the second range of steering wheel angles being entirely less than the starting angle.
5 more elements
Dependencies are inferred from the claim text.