Magnetically-latchable fluid control valve system
AssigneeSturman Industries, Inc.
InventorsBruce G. Johnson, Oded E. Sturman, Kathy M. Misovec, Steve E. Massey
Life of this patent
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Abstract
A hydraulic valve control system that includes a plurality of digitally actuated magnetically-latchable four-way valves that directly or indirectly control the position of a hydraulic actuator. The digitally actuated magnetically-latchable four-way valves are controlled by a controller that can control the valves in accordance with a servo routine. The servo routine may include the computation of a plurality of cost functions and the selection of an action that corresponds to the lowest cost.
Claims16
A fluid driven control valve system adapted to be coupled to a supply line and a drain line and further adapted to control movement of a fluid driven actuator, said fluid driven control valve system comprising:
- the fluid driven actuator having a first fluid chamber and a second fluid chamber;
- a first digitally actuated magnetically-latchable four-way valve, the first digitally actuated magnetically-latchable four-way valve actuatable to couple the first fluid chamber to the supply line and the second fluid chamber to the drain line;
- a second digitally actuated magnetically-latchable four-way valve, the second digitally actuated magnetically-latchable four-way valve actuatable to couple the first fluid chamber to the drain line and the second fluid chamber to the supply line;
- and
- a controller coupled to the first and second digitally actuated magnetically-latchable four-way valves, the controller operable to selectively actuate at least one of said first and second digitally actuated magnetically-latchable four-way valves.
A control valve system adapted to be coupled to a supply line and a drain line, comprising:
- a main valve having a spool, a first fluid chamber and a second fluid chamber, the spool being coupled to the first fluid chamber at one end and the second fluid chamber at another end;
- a first digitally actuated magnetically-latchable four-way valve coupled to the supply and drain lines and the main valve, the first digitally actuated magnetically-latchable four-way valve being actuatable to couple said first fluid chamber to the drain line and the second fluid chamber to the supply line;
- a second digitally actuated magnetically-latchable four-way valve coupled to the supply and drain lines and the main valve, the second digitally actuated magnetically-latchable four-way valve being actuatable to couple the first fluid chamber to the supply line and the second fluid chamber to the drain line;
- and
- a controller coupled to the first and second digitally actuated magnetically-latchable four-way valves, the controller to actuate said first and second digitally actuated magnetically-latchable four-way valves.
A method of operating a fluid driven control valve system adapted to control movement of a fluid driven actuator, said method comprising the steps of:
- accepting a desired fluid driven actuator position;
- sensing an actual fluid driven actuator position;
- computing an error that is a function of the actual and desired fluid driven actuator positions;
- calculating a plurality of cost functions which are a function of the error;
- determining the lowest cost function;
- and,
- switching a pair of digitally actuated magnetically-latchable four-way valves to a collective valve state associated with the lowest cost function, wherein the four-way valves control movement of the fluid driven actuator.
Dependencies are inferred from the claim text.