System and method for controlling hydraulic flow
AssigneeCaterpillar Inc.
InventorStephen V. Lunzman
Life of this patent
Estimating the term…
Abstract
A method is provided for controlling hydraulic flow through a valve in fluid communication with a pump and a hydraulic actuator. The method includes monitoring load pressure of the valve, and selecting a flow limit and a pressure limit of the valve. A flow-pressure relationship in the valve is determined based on the flow limit, the pressure limit, and a desired flow-pressure characteristic. A hydraulic flow rate command is computed based on the determined flow pressure relationship and the monitored load pressure of the valve.
Claims20
A method for controlling hydraulic flow through a valve in fluid communication with a pump and a hydraulic actuator, comprising:
- monitoring load pressure of the valve;
- selecting a flow limit and a pressure limit of the valve;
- determining a flow-pressure relationship in the valve based on the flow limit, the pressure limit, and a desired flow-pressure characteristic;
- and
- computing a hydraulic flow rate command based on the determined flow pressure relationship and the monitored load pressure of the valve.
A method for providing a plurality of flow-pressure relationships in a valve in fluid communication with a pump and a hydraulic actuator, comprising:
- selecting a flow limit and a pressure limit of the valve;
- determining a first flow-pressure relationship of the plurality of flow-pressure relationships in the valve based on the flow limit, the pressure limit, and a first desired flow-pressure characteristic;
- and
- determining a second flow-pressure relationship of the plurality of flow-pressure relationships in the valve based on the flow limit, the pressure limit, and a second desired flow-pressure characteristic different from the first desired flow-pressure characteristic.
A system for controlling hydraulic flow in a valve in fluid communication with a pump and a hydraulic actuator, the valve having an inlet port and an outlet port, the system comprising:
- a pressure sensor assembly for monitoring load pressure;
- and
- a flow controller electrically coupled to the pressure sensor assembly, the controller including a flow-pressure control unit configured to determine a flow-pressure relationship in the valve based on a flow limit and a pressure limit of the valve and a desired flow-pressure characteristic.
A system for controlling hydraulic flow, comprising:
- an independent metering valve having an inlet port and an outlet port;
- a pressure sensor assembly for monitoring load pressure of the independent metering valve;
- and
- a flow controller electrically coupled to the pressure sensor assembly, the controller including:
- a flow-pressure control unit configured to determine a flow-pressure relationship in the independent metering valve based on a flow limit and a pressure limit of the valve and a desired flow-pressure characteristic;
- and
- a flow-pressure control unit configured to compute a hydraulic flow rate command based on the determined flow-pressure relationship and the monitored load pressure of the independent metering valve,
- the controller being preprogrammed with the desired flow-pressure characteristic.
A method for controlling movement of a hydraulic actuator, comprising:
- storing predetermined valve operational characteristics;
- generating input signals based on movement of an input device;
- simulating a flow-pressure relationship based on the input signals and the predetermined valve operational characteristics;
- generating a valve command based on the flow-pressure simulation;
- and
- causing movement of the actuator through communication of the valve command with a control valve in fluid communication with the actuator.
Dependencies are inferred from the claim text.