RIDE HEIGHT LEVELING CONTROL FOR DUAL AIR SPRING CONFIGURATION

• US 20100259018A1
• Filed: 04/09/2009
• Published: 10/14/2010
• Est. Priority Date: 04/09/2009
• Status: Active Grant

• Current Assignee: ArvinMeritor Technology LLC (Meritor, Inc. (Nevada))
• Original Assignee: ArvinMeritor Technology LLC (Meritor, Inc. (Nevada))
• Inventors: Honig, Jonathan L., VanRaaphorst, David A.
• Granted Patent: US 7,950,674 B2
• Time in Patent Office: Days
• US Class Current: 280/5.514
• CPC Class Codes: B60G 11/28 characterised by means specially adapted for attaching the spring to axle or sprung part of the vehicle
• CPC Class Codes: B60G 17/0155 pneumatic unit
• CPC Class Codes: B60G 17/04 fluid spring characteristics
• CPC Class Codes: B60G 17/0485 the springs being pneumatic springs with a flexible wall, e.g. with levelling valves
• CPC Class Codes: B60G 17/0521 the spring having a flexible wall
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2202/314 The spring being a pneumatic spring
• CPC Class Codes: B60G 2202/412 Pneumatic actuator
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2500/201 Air spring system type
• CPC Class Codes: B60G 2500/2021 Arrangement of valves
• CPC Class Codes: B60G 2500/22 Spring constant
• CPC Class Codes: B60G 2500/30 Height or ground clearance
• CPC Class Codes: B60G 2600/182 Active control means
• CPC Class Codes: B60G 2600/70 Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2800/912 Attitude Control; levelling control
• CPC Class Codes: B60G 2800/914 Height Control System

Abstract

An air suspension system is configured to adjust and maintain a desired vehicle ride height and spring rate. The air suspension system includes a plurality of air spring assemblies that each include a piston airbag and a primary airbag mounted around the piston airbag. A controller receives ride height input data and adjusts pressures within the primary and piston airbags until the desired ride height and spring rate is achieved. The controller accommodates for system hardware differences by varying flow rates into and out of the primary and piston airbags relative to each other.

Claims

1. An air suspension system comprising:

a plurality of air spring assemblies, each air spring assembly including a piston airbag and a primary air bag mounted adjacent to the piston airbag with each air spring assembly being set at an initial ride height;

a plurality of valve assemblies, with at least one valve assembly being associated with each of said primary and said piston airbags; and

a controller configured to adjust and maintain a desired ride height and spring rate wherein said controller actively varies pressure within said primary and said piston airbags to achieve the desired ride height and spring rate by varying flow rates into and out of said primary and said piston airbags via associated valve assemblies.

2. The air suspension system according to claim 1 wherein said controller actively varies spring force and spring rate of each air spring assembly independently of any other air spring assemblies during vehicle operation.

3. The air suspension system according to claim 2 wherein said controller continuously adjusts spring force and spring rate of each of the air spring assemblies by controlling air flow into and out of each piston airbag and each primary airbag.

4. The air suspension system according to claim 1 wherein said controller simultaneously adjusts flow rates into both said primary and said piston airbag within a common air spring assembly to adjust to said desired ride height and spring rate.

5. The air suspension system according to claim 4 wherein said controller provides a first flow rate for said primary airbag of said common air spring assembly and a second flow rate for said piston airbag of said common air spring assembly that is different than said first flow rate.

6. The air suspension system according to claim 1 wherein said controller identifies hardware differences between various suspension components and modifies said flow rates to accommodate these hardware differences.

7. The air suspension system according to claim 1 including a plurality of ride height sensors continuously monitoring ride height and communicating ride height data to said controller as an input, and wherein said controller compares said desired ride height to the most recently received input and actively adjusts ride height to maintain said desired ride height.

8. The air suspension system according to claim 1 wherein, once said desired ride height is achieved, said controller adjusts ride height via controlling flow rates into and out of at least one of said primary airbag and piston airbag to maintain said desired ride height.

9. A method of adjusting ride height in an air suspension system comprising the steps of:

(a) providing a plurality of air spring assemblies, each air spring assembly including a piston airbag and a primary air bag mounted adjacent to the piston airbag;

(b) receiving a ride height change request defining a desired ride height;

(c) determining current ride height; and

(d) actively controlling flow rates into and out of the primary and piston airbags until the desired ride height is achieved.

10. The method according to claim 9 wherein step (d) includes simultaneously adjusting pressure in the primary and the piston airbags within a common air spring assembly.

11. The method according to claim 10 wherein step (d) includes inflating or deflating the piston airbag at a first flow rate and inflating or deflating the primary airbag at a second flow rate different than the first flow rate.

12. The method according to claim 9 including identifying hardware differences between various suspension components and modifying the flow rates to accommodate these hardware differences.

13. The method according to claim 9 including adjusting flow rates into and out of at least one the primary airbag and piston airbags once the desired ride height is achieved to maintain the desired ride height.