ACTIVE SUSPENSION SYSTEM

• US 20130030650A1
• Filed: 07/28/2011
• Published: 01/31/2013
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Romig, Bernard E., Norris, William R.
• Granted Patent: US 8,825,294 B2
• Time in Patent Office: Days
• US Class Current: 701/40
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 17/0182 involving parameter estimation, e.g. observer, Kalman filter
• CPC Class Codes: B60G 2400/63 Location of the center of gravity
• CPC Class Codes: B60G 2600/1879 Fuzzy Logic Control
• CPC Class Codes: B60G 2800/915 Suspension load distribution

Abstract

A method of controlling a vehicle suspension system including the steps of detecting, computing and altering the center of gravity of the vehicle. The detecting step includes the detecting of a center of gravity of the vehicle thereby defining a detected center of gravity. The computing step includes computing what alteration of a plurality of actuators is needed to substantially reduce a value of a difference between the detected center of gravity and a preferred center of gravity using a fuzzy relations control strategy. The computing step is carried out in a controller. The altering step includes altering the center of gravity of the vehicle by way of the controller actuating at least one of the actuators connected to suspension elements of the vehicle dependent upon the alteration arrived at in the computing step.

Claims

1. A vehicle suspension control system, comprising:

a plurality of ground engaging traction devices;

a plurality of actuators, with at least one of said plurality of actuators correspondingly associated with each of said plurality of ground engaging traction devices;

a plurality of sensors positioned about the vehicle; and

a controller controllingly connected to each of said plurality of actuators, said controller receiving information from said plurality of sensors, said information relating to at least one of mass distributions of the vehicle and mass distributions of loads carried by the vehicle thereby defining distributed masses, said controller activating said plurality of actuators dependent upon said information and dependent upon a desired center of gravity of the vehicle to thereby alter a center of gravity of the vehicle, said controller computing what alteration of said actuators is needed to substantially reduce a value of a difference between said center of gravity of the vehicle and said desired center of gravity using a fuzzy relations control strategy.

2. The vehicle of claim 1, wherein said fuzzy relations control strategy is a hierarchical method carried out on said controller.

3. The vehicle of claim 2, wherein said controller is a multi-objective nonlinear controller.

4. The vehicle of claim 1, wherein said fuzzy relations control strategy uses a reduced size rule base.

5. The vehicle of claim 4, wherein said fuzzy relations control strategy includes minimizing system error states using fuzzy membership functions and linguistic variables.

6. The vehicle of claim 5, wherein the linguistic variables are used as classifiers within a rule based structure to define a relative importance of the fuzzy membership functions.

7. The vehicle of claim 6, wherein the linguistic variables each have a corresponding degree of importance assigned thereto, said degree of importance being dependent upon said error states.

8. The vehicle of claim 1, wherein the vehicle is one of an agricultural vehicle, a construction vehicle, and a forestry vehicle.

9. The vehicle of claim 1, wherein said fuzzy relations control strategy includes said activation of said actuators dependent on a current state of the vehicle.

10. The vehicle of claim 9, wherein said fuzzy relations control strategy also includes said activation of said actuators being dependent on said current state of the vehicle without any prior state input.

11. A method of controlling a vehicle suspension system, the method comprising:

detecting a center of gravity of the vehicle thereby defining a detected center of gravity;

computing what alteration of a plurality of actuators is needed to substantially reduce a value of a difference between said detected center of gravity and a preferred center of gravity using a fuzzy relations control strategy, said computing step being carried out in a controller; and

altering the center of gravity of the vehicle by way of said controller actuating at least one of said actuators connected to suspension elements of the vehicle dependent upon said alteration arrived at in said computing step.

12. The method of claim 11, wherein said fuzzy relations control strategy is a hierarchical method carried out on said controller.

13. The method of claim 12, wherein said controller is a multi-objective nonlinear controller.

14. The method of claim 11, wherein said fuzzy relations control strategy uses a reduced size rule base.

15. The method of claim 14, wherein said fuzzy relations control strategy includes the step of minimizing system error states using fuzzy membership functions and linguistic variables.

16. The method of claim 15, wherein the linguistic variables are used as classifiers within a rule based structure to define a relative importance of the fuzzy membership functions.

17. The method of claim 16, wherein the linguistic variables each have a corresponding degree of importance assigned thereto, said degree of importance being dependent upon said error states.

18. The method of claim 11, wherein the vehicle is one of an agricultural vehicle, a construction vehicle, and a forestry vehicle.

19. The method of claim 11, wherein said fuzzy relations control strategy includes said actuating of said actuators being dependent on a current state of the vehicle.

20. The method of claim 19, wherein said fuzzy relations control strategy also includes said actuating of said actuators being dependent on said current state of the vehicle without any prior state input.