System and method for situationally optimized turning assistance

1. A vehicle control system comprising:

electric motors associated with front and rear wheels of the vehicle;

a plurality of vehicle sensors to receive information including driving surface type, vehicle speed and handwheel position;

a controller operably coupled to the electric motors and the sensors to control wheel slip during a turn based on the driving surface type, the vehicle speed and the handwheel position; and

a torque control module operably coupled to the controller and to front wheels of the vehicle and rear wheels of the vehicle,

wherein the vehicle control system further comprises a plurality of operator selectable modes of operation that each define respective different functions,

wherein the torque control module applies different torque values during the turn responsive to operator selection of a corresponding one of the modes of operation and detection of a trigger event, and

wherein the trigger event comprises detecting that a limit of rotation of a handwheel is reached when a current steering wheel angle of the handwheel is equal to a maximum steering wheel angle, and responsive to the detecting the limit of rotation of the handwheel is reached, measuring additional torque placed on the handwheel to apply the different torque values based on the additional torque measured.

2. The system of claim 1 , wherein responsive to control by the controller, the torque control module selectively applies the different torque values to at least an inside one of the rear wheels relative to an outside one of the rear wheels.

3. The system of claim 2 , wherein selectively applying the different torque values comprises applying a negative torque to the inside rear wheel and applying a positive torque to the front wheels and the outside rear wheel during the turn.

4. The system of claim 3 , wherein the negative torque is applied by operating an electric motor associated with the inside rear wheel in a reverse direction.

5. The system of claim 2 , wherein selectively applying the different torque values comprises applying a different torque to each of the front wheels and each of the rear wheels.

6. The system of claim 1 , wherein speed changes associated with the applying the different torque values change nonlinearly with respect to changes in the application of the additional torque to the handwheel.

7. The system of claim 1 , wherein the controller controls wheel slip based on a selected slip table from a plurality of slip tables, the selected slip table defining an amount of slip between an inside wheel and an outside wheel of one or both of the front wheels and the rear wheels.

8. A vehicle control system comprising:

electric motors associated with front and rear wheels of the vehicle;

a plurality of vehicle sensors to receive information including driving surface type, vehicle speed and handwheel position; and

a controller operably coupled to the electric motors and the sensors to control wheel slip during a turn based on the driving surface type, the vehicle speed and the handwheel position,

wherein a torque control module is operably coupled to the controller and to the front wheels and rear wheels of the vehicle

wherein the controller controls wheel slip based on a selected slip table from a plurality of slip tables, the selected slip table defining an amount of slip between an inside wheel and an outside wheel of one or both of the front wheels and the rear wheels, and

wherein the selected slip table is chosen based on the driving surface type,

wherein the torque control module applies different torque values during the turn responsive to operator selection of a corresponding one of the modes of operation and detection of a trigger event, and

wherein the trigger event comprises detecting that a limit of rotation of a handwheel is reached when a current steering wheel angle of the handwheel is equal to a maximum steering wheel angle, and responsive to the detecting the limit of rotation of the handwheel is reached, measuring additional torque placed on the handwheel to apply the different torque values based on the additional torque measured.

9. The system of claim 8 , further comprising:

a torque control module operably coupled to the controller and/or to front wheels of the vehicle and rear wheels of the vehicle, the torque control module being operable, responsive to control by the controller, to selectively apply different torque values to at least an inside one of the rear wheels relative to an outside one of the rear wheels,

wherein the controller controls vehicle operation in any of a plurality of operator selectable modes of operation, and

wherein the torque control module applies the different torque values during the turn responsive to operator selection of a corresponding one of the modes of operation and detection of a trigger event.

10. The system of claim 8 , wherein the driving surface type is determined locally at the vehicle based on surface information provided by a surface sensor.

11. The system of claim 10 , wherein the surface sensor is a camera.

12. The system of claim 8 , wherein the driving surface type is determined based on a mode selection made by a driver of the vehicle.

13. The system of claim 8 , wherein the driving surface type is determined based on a location of the vehicle.

14. A method of providing automated application of turn radius reduction for a vehicle, the method comprising:

receiving a mode selection selecting a turning radius reduction mode;

receiving steering wheel angle and vehicle speed information to determine if turn radius reduction criteria are met during a turn;

determining a surface type on which the vehicle is operating; and

in response to the turn radius reduction criteria being met, applying a torque differential to at least an inside rear wheel and an outside rear wheel of the vehicle based on a steering wheel angle, vehicle speed information, the surface type and a selected mode of operation,

wherein a torque control module applies different torque values during the turn responsive to operator selection of a corresponding one of the modes of operation and detection of a trigger event, and

wherein the trigger event comprises detecting that a limit of rotation of a handwheel is reached when a current steering wheel angle of the handwheel is equal to a maximum steering wheel angle, and responsive to the detecting the limit of rotation of the handwheel is reached, measuring additional torque placed on the handwheel to apply the different torque values based on the additional torque measured.

15. The method of claim 14 , wherein determining the surface type on which the vehicle is operating comprises determining the surface type locally at the vehicle based on surface information provided by a surface sensor.

16. The method of claim 14 , wherein determining the surface type on which the vehicle is operating comprises determining the surface type based on the mode selection.

17. The method of claim 14 , wherein determining the surface type on which the vehicle is operating comprises determining the surface type based on a location of the vehicle.

18. The method of claim 14 , wherein applying the torque differential further comprises applying the torque differential also to an inside rear wheel relative to an outside rear wheel of the vehicle.

19. The method of claim 14 , wherein applying the torque differential comprises applying a positive torque to the outside rear wheel and applying a negative torque to the inside rear wheel.