Hydraulics management for bounded implements
First Claim
1. A machine controller for controlling a flow of hydraulic fluid to each of two actuators associated with a machine, wherein one of the actuators is a bounded actuator, the fluid flow of which is constrained to remain between an upper and lower bound, and a non-bounded actuator, the controller comprising:
- a control input for receiving operator commands related to desired bounded and non-bounded actuator movements;
a translation module for translating the operator commands into a first valve control command associated with the bounded actuator and a second valve control command associated with the non-bounded actuator; and
a balancing module configured to reduce the first valve control command to form a first adjusted valve control command if an available flow of hydraulic fluid is insufficient to service the first and second valve control commands, and if the difference between the available flow and a flow associated with the second valve control command is less than a flow corresponding to the first valve control command, wherein the first adjusted valve control command is the lesser of the first valve control command and a nonlinear threshold function of machine engine speed.
1 Assignment
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Accused Products
Abstract
A method of allocating hydraulic fluid between actuators in a machine accepts a first command to provide a first requested fluid flow to a first actuator, wherein the first actuator is a bounded actuator such as a steering actuator, and a second command to provide a second requested fluid flow to a second actuator. The system adjusts the first and second commands to produce adjusted first and second commands corresponding to adjusted first and second fluid flows, such that the sum of the adjusted first and second fluid flows is less than or equal to a maximum available flow and the adjusted first fluid flow meets or exceeds the lesser of the first requested fluid flow and a threshold curve that is a function of engine speed or other variable.
45 Citations
20 Claims
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1. A machine controller for controlling a flow of hydraulic fluid to each of two actuators associated with a machine, wherein one of the actuators is a bounded actuator, the fluid flow of which is constrained to remain between an upper and lower bound, and a non-bounded actuator, the controller comprising:
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a control input for receiving operator commands related to desired bounded and non-bounded actuator movements; a translation module for translating the operator commands into a first valve control command associated with the bounded actuator and a second valve control command associated with the non-bounded actuator; and a balancing module configured to reduce the first valve control command to form a first adjusted valve control command if an available flow of hydraulic fluid is insufficient to service the first and second valve control commands, and if the difference between the available flow and a flow associated with the second valve control command is less than a flow corresponding to the first valve control command, wherein the first adjusted valve control command is the lesser of the first valve control command and a nonlinear threshold function of machine engine speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of allocating hydraulic fluid between a first and second hydraulic actuator in a machine having an engine having a speed, wherein the engine is linked to a pressurized fluid source to provide pressurized fluid to the first and second hydraulic actuators, wherein the first hydraulic actuator is a bounded actuator, the fluid flow of which is constrained to remain between an upper and lower bound, and the second hydraulic actuator is a non-bounded actuator, the method comprising:
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receiving a first command to provide a first requested fluid flow to the bounded actuator and a second command to provide a second requested fluid flow to the non-bounded actuator; identifying a nonlinear threshold curve that specifies fluid flows as a function of engine speed; and reducing the first and second commands to produce modified first and second commands for producing modified first and second fluid flows, such that (1) the sum of the modified first and second fluid flows is less than or equal to an available fluid flow, and (2) the modified first flow meets or exceeds the lesser of the first requested fluid flow and a current fluid flow specified by the threshold curve. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A machine having a hydraulic priority system for controlling hydraulic fluid flow among multiple hydraulic actuators, the machine comprising:
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a power source and a hydraulic pump linked to the power source for providing a current available fluid flow; at least one bounded actuator, the fluid flow of which is constrained to remain between an upper and lower bound; at least one non-bounded actuator, the fluid flow of which is not bounded except by the current available fluid flow; at least one valve associated with each actuator for controlling the flow of hydraulic fluid to the actuator; at least one control input for allowing an operator to indicate first and second desired fluid flows respectively for the bounded and non-bounded actuators; and a controller for receiving from the control input an indication of the first and second desired fluid flows, and modifying the first desired fluid flow to a modified first fluid flow based on the current available fluid flow and a nonlinear threshold curve that specifies a fluid flow as a function of a second variable. - View Dependent Claims (19, 20)
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Specification