STEERABLE VEHICLE

• US 20180050724A1
• Filed: 10/31/2017
• Published: 02/22/2018
• Est. Priority Date: 09/07/2011
• Status: Active Grant

• Current Assignee: Blue Leaf IP Incorporated (CNH Industrial N.V.)
• Original Assignee: CNH Industrial America LLC (CNH Industrial N.V.)
• Inventors: Morselli, Riccardo, Canuto, Francesco, Turco, Patrizio, Raffone, Enrico
• Granted Patent: US 10,710,629 B2
• Time in Patent Office: Days
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: B62D 1/04 Hand wheels
• CPC Class Codes: B62D 1/12 Hand levers
• CPC Class Codes: B62D 1/22 Alternative steering-control elements, e.g. for teaching purposes
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 5/0463 calculating assisting torque from the motor based on driver input
• CPC Class Codes: B62D 5/093 Telemotor driven by steering wheel movement hydraulic steering gear B62D3/14
• CPC Class Codes: B62D 6/007 adjustable by the driver, e.g. sport mode

Abstract

A steerable, self-propelled vehicle includes a rotatable steering column that is connected to control the steering angle of one or more ground-engaging members of the vehicle. The vehicle includes between the steering column and the ground-engaging member a first steering servomechanism having at least a first steering assistance characteristic; a second steering servomechanism having a second steering assistance characteristic also being connected to act on the steering column. A controller is provided for causing the first and second steering assistance characteristics to influence the steering of the vehicle in dependence on one or more one or more control commands generated in the controller.

Claims

1. A steerable vehicle, comprising:

a steering mechanism having a rotatable steering column;

a first steering servomechanism comprising a hydraulic steering servomechanism, wherein the hydraulic steering servomechanism comprises a hydraulic steering valve coupled to the rotatable steering column and at least one hydraulic steering cylinder fluidly coupled to the hydraulic steering valve by hydraulic lines, and wherein the hydraulic steering valve is configured to control a hydraulic flow in the hydraulic lines based on a rotational angle of the rotatable steering column to drive the at least one hydraulic steering cylinder to adjust a steering angle of at least one ground-engaging member of the steerable vehicle;

a second steering servomechanism comprising an electric power steering servomechanism, wherein the electric power steering servomechanism comprises a motor configured to control a torque on the rotatable steering column to establish a steering assistance characteristic; and

a controller configured to control the steering assistance characteristic by outputting control signals indicative of a magnitude and a direction of the torque to influence steering of the steerable vehicle;

wherein the at least one ground-engaging member is not coupled to the rotatable steering column by a mechanical linkage.

2. The steerable vehicle of claim 1, comprising a steering wheel mechanically coupled to the rotatable steering column.

3. The steerable vehicle of claim 1, wherein the controller is configured to control the steering assistance characteristic based at least on one of a speed of the steerable vehicle, a speed of the at least one ground-engaging member, the rotational angle of the rotatable steering column, a position of the motor, a position of a joystick, a steerable wheel alignment angle, the torque on the rotatable steering column, hydraulic pressure in the at least one hydraulic steering cylinder, operator input torque to the rotatable steering column, and current or voltage supplied to the motor.

4. The steerable vehicle of claim 1, comprising a human-machine interface (HMI) configured to receive input commands indicative of selection of one of a plurality of programmed modes of operation of the second steering servomechanism.

5. The steerable vehicle of claim 4, wherein a first programmed mode of operation of the plurality of programmed modes of operation comprises steering during movement of the steerable vehicle within a field headland, and a second programmed mode of operation of the plurality of programed modes of operation comprises steering during movement of the steerable vehicle within a field and along a road.

6. The steerable vehicle of claim 5, wherein the first programmed mode of operation comprises a steering feedback sub-mode, a torque-free sub-mode, an automatic steering centering sub-mode, and a lock-to-lock assistance sub-mode;

and

wherein the second programmed mode of operation comprises a steering feedback sub-mode, an automatic steering centering sub-mode, and a torque-free sub-mode.

7. The steerable vehicle of claim 1, wherein the controller is configured to output second control signals to the motor to instruct the motor to drive the rotatable steering column to steer the steerable vehicle along a target route in response to engagement of automatic guidance.

8. The steerable vehicle of claim 7, wherein the controller is configured to disengage the automatic guidance in response to the magnitude of the torque exceeding a threshold torque.

9. The steerable vehicle of claim 1, wherein the hydraulic steering valve is coupled to the rotatable steering column at a first location, the motor is coupled to the rotatable steering column at a second location, and the first location is different than the second location.

10. A steerable vehicle, comprising:

a steering mechanism having a rotatable steering column;

a first sensor configured to output a first sensor signal indicative of a steering angle of at least one ground-engaging member of the steerable vehicle;

a first steering servomechanism comprising a hydraulic steering servomechanism, wherein the hydraulic steering servomechanism comprises a hydraulic steering valve coupled to the rotatable steering column and at least one hydraulic steering cylinder fluidly coupled to the hydraulic steering valve by hydraulic lines, and wherein the hydraulic steering valve is configured to control a hydraulic flow in the hydraulic lines based on a rotational angle of the rotatable steering column to drive the at least one hydraulic steering cylinder to adjust the steering angle of the at least one ground-engaging member;

a second steering servomechanism comprising an electric power steering servomechanism, wherein the electric power steering servomechanism comprises a motor configured to control a torque on the rotatable steering column to establish a steering assistance characteristic; and

a controller communicatively coupled to the first sensor and to the motor, wherein the controller is configured to control the steering assistance characteristic by outputting control signals indicative of a magnitude and a direction of the torque based at least in part on the first sensor signal to influence steering of the steerable vehicle;

wherein the at least one ground-engaging member is not coupled to the rotatable steering column by a mechanical linkage.

11. The steerable vehicle of claim 10, wherein the first sensor comprises a Hall effect sensor.

12. The steerable vehicle of claim 10, comprising a second sensor configured to output a second sensor signal indicative of the torque applied to the rotatable steering column, wherein the controller is communicatively coupled to the second sensor, and the controller is configured to control the steering assistance characteristic by outputting the control signals indicative of the magnitude and the direction of the torque based at least in part on the first sensor signal and the second sensor signal.

13. The steerable vehicle of claim 12, wherein the controller is configured to output second control signals to the motor to instruct the motor to drive the rotatable steering column to steer the steerable vehicle along a target route in response to engagement of automatic guidance, and the controller is configured to disengage the automatic guidance in response to receiving the second sensor signal indicative of the magnitude of the torque exceeding a threshold torque.

14. The steerable vehicle of claim 10, comprising a third sensor configured to output a third sensor signal indicative of a speed of the steerable vehicle or a speed of the at least one ground-engaging member, wherein the controller is communicatively coupled to the third sensor, and the controller is configured to control the steering assistance characteristic by outputting the control signals indicative of the magnitude and the direction of the torque based at least in part on the first sensor signal and the third sensor signal.

15. The steerable vehicle of claim 10, comprising a joystick communicatively coupled to the controller, wherein the joystick is configured to output a joystick signal indicative of a position of the joystick, and the controller is configured to instruct the motor to drive the rotatable steering column to rotate based at least in part on the joystick signal.

16. The steerable vehicle of claim 10, wherein the hydraulic steering valve is coupled to the rotatable steering column at a first location, the motor is coupled to the rotatable steering column at a second location, and the first location is different than the second location.

17. A steerable vehicle, comprising:

a steering mechanism having a rotatable steering column configured to be mechanically connected to at least one ground-engaging member of the steerable vehicle to control a steering angle of the at least one ground-engaging member;

a first steering servomechanism comprising a hydraulic steering servomechanism configured to establish a first steering assistance characteristic, wherein the hydraulic steering servomechanism comprises a hydraulic steering valve coupled to the rotatable steering column and at least one hydraulic steering cylinder fluidly coupled to the hydraulic steering valve by hydraulic lines, wherein the hydraulic steering valve is configured to control a hydraulic flow in the hydraulic lines based on a rotational angle of the rotatable steering column to drive the at least one hydraulic steering cylinder to adjust the steering angle of the at least one ground-engaging member, and wherein the hydraulic steering valve is coupled to the rotatable steering column at a first location;

a second steering servomechanism comprising an electric power steering servomechanism, wherein the electric power steering servomechanism comprises a motor configured to control a torque on the rotatable steering column to establish a second steering assistance characteristic, and wherein the motor is coupled to the rotatable steering column at a second location, different from the first location; and

a controller communicatively coupled to the motor, wherein the controller is configured to control at least the second steering assistance characteristic by outputting control signals indicative of a magnitude and a direction of the torque to influence steering of the steerable vehicle.

18. The steerable vehicle of claim 17, wherein the hydraulic steering servomechanism comprises a pump fluidly coupled to the hydraulic steering valve, the controller is communicatively coupled to the pump, and the controller is configured to control the first steering assistance characteristic by outputting second control signals indicative of a hydraulic fluid pressure to influence the steering of the steerable vehicle.

19. The steerable vehicle of claim 17, wherein the controller is configured to output third control signals to the motor to instruct the motor to drive the rotatable steering column to steer the steerable vehicle along a target route in response to engagement of automatic guidance, and wherein the controller is configured to disengage the automatic guidance in response to the magnitude of the torque exceeding a threshold torque.

20. The steerable vehicle of claim 17, comprising a sensor configured to output a sensor signal indicative of the steering angle of the at least one ground-engaging member, wherein the controller is communicatively coupled to the sensor, and the controller is configured to control at least the second steering assistance characteristic based at least in part on the sensor signal.