Center seeking suspension system

A fluid strut for a vehicle suspension system comprising:

• an outer cylinder adapted for attachment to a vehicle chassis and including a first fluid chamber for receiving a compressible fluid;
• an inner cylinder at least partially received within said first fluid chamber, said inner cylinder including a second fluid chamber that is in fluid communication with the first fluid chamber;
• a plate abutting against an inner surface of said outer cylinder and abutting against an outer surface of said inner cylinder, said plate separating said first fluid chamber into a main chamber and an auxiliary chamber;
• a rod adapted for attachment to a vehicle wheel, said rod extending into said second fluid chamber;
• a first valve directing flow between said main chamber and said second fluid chamber;
• a second valve directing flow between said auxiliary chamber and said second fluid chamber;
• a transfer pump positioned within said inner cylinder between said second valve and an end of said rod;
• and
• a controller in communication with said first and said second valves to control fluid communication of the compressible fluid between said main chamber, said second fluid chamber, and said auxiliary chamber to provide a desired suspension rate during vehicle operation and to vary ride height as needed.

A method of controlling an active suspension system comprising the steps of:

• (a) mounting an outer cylinder to a vehicle chassis;
• (b) mounting an inner cylinder within a first fluid chamber defined by the outer cylinder;
• (c) mounting a rod to a vehicle wheel such that the rod extends into a second fluid chamber defined by the inner cylinder;
• (d) holding the inner and outer cylinders fixed relative to each other;
• (e) moving the rod within the second fluid chamber in response to a suspension input;
• and
• (f) controlling flow of a compressible fluid between the first and second fluid chambers to adjust suspension rate and ride height as needed.