Hydraulic balancing for steering management
First Claim
1. A machine controller for controlling a flow of hydraulic fluid to each of two or more actuators associated with a machine, wherein at least one of the actuators is a steering actuator for steering the machine and at least one of the actuators is a non-steering actuator for performing a function other than steering the machine, the controller comprising:
- a control input for receiving operator commands related to desired steering and non-steering actuator movements;
a translation module for translating the operator commands into a first valve control command associated with the steering actuator and a second valve control command associated with the non-steering actuator; and
a balancing module configured to generate a first adjusted valve control command from the first valve control command wherein the first adjusted valve control command is the lesser of the first valve control command 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, and if the flow corresponding to the first valve control command is less than a nonlinear threshold function of machine engine speed, the balancing module being further configured to provide the first adjusted valve control command to one of the two or more actuators associated with the machine.
1 Assignment
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Accused Products
Abstract
A method of allocating hydraulic fluid between two or more actuators in a machine processes a first command intended to provide a first requested fluid flow to a steering actuator for steering the machine, and a second command intended to provide a second requested fluid flow to a non-steeling actuator, such as a lift or tilt actuator. The system modifies the first and second commands to produce modified first and second commands corresponding to modified first and second fluid flows, such that the sum of the adjusted first and second fluid flows is less than or equal to a currently available flow and the modified first fluid flow meets or exceeds the lesser of the first requested fluid flow and a threshold curve that is a function of a machine variable such as engine speed or other variable or parameter.
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Citations
19 Claims
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1. A machine controller for controlling a flow of hydraulic fluid to each of two or more actuators associated with a machine, wherein at least one of the actuators is a steering actuator for steering the machine and at least one of the actuators is a non-steering actuator for performing a function other than steering the machine, the controller comprising:
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a control input for receiving operator commands related to desired steering and non-steering actuator movements; a translation module for translating the operator commands into a first valve control command associated with the steering actuator and a second valve control command associated with the non-steering actuator; and a balancing module configured to generate a first adjusted valve control command from the first valve control command wherein the first adjusted valve control command is the lesser of the first valve control command 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, and if the flow corresponding to the first valve control command is less than a nonlinear threshold function of machine engine speed, the balancing module being further configured to provide the first adjusted valve control command to one of the two or more actuators associated with the machine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. 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 steering actuator for steering the machine and the second hydraulic actuator is a non-steering actuator for performing a function other than steering the machine, the method comprising:
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receiving a first command to provide a first requested fluid flow to the steering actuator and a second command to provide a second requested fluid flow to the non-steering actuator; identifying a nonlinear threshold curve that specifies fluid flows as a function of engine speed; producing modified first and second commands for producing modified first and second fluid flows based on the first and second commands, 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 fluid flow specified by the threshold curve; and providing the modified first and second commands to the steering actuator and the non-steering actuator respectively, to produce flows through the steering actuator and the non-steering actuator corresponding to the modified first and second fluid flows respectively. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A machine having a hydraulic priority system for controlling hydraulic fluid flow among multiple hydraulic actuators, the machine comprising:
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at least one steering actuator for steering the machine; at least one non-steering actuator for performing a function other than steering the machine; a power source and a hydraulic pump linked to the power source for providing a 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 steering and non-steering 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 (18, 19)
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Specification