Closed loop transmission torque control
AssigneeCaterpillar Inc.
InventorsJason Stoller, Adam Vaccari
Life of this patent
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Abstract
The described system and method provide improved transmission performance and response with closed loop torque feedback by implementing situational gain scheduling and nonlinear control techniques for continuously variable transmissions. The system uses contextual information regarding the operation of the machine to determine a gain to be applied in associated PID control logic. In an embodiment, the determined gain is applied in the integral portion of the closed loop controller.
Claims20
A method for providing output torque control in a hydrostatic transmission, the system comprising:
- determining respective values for a selected plurality of machine operation parameters;
- identifying a machine state based on the determined values of the selected plurality of machine operation parameters and calculating a gain value based on the identified machine state;
- and
- executing output torque control of the hydrostatic transmission via a closed loop control module and an open loop control module, wherein the closed loop control module applies the calculated gain value.
A controller for providing output torque control in a hydrostatic transmission, the controller comprising a computer readable medium having thereon computer executable instructions comprising:
- instructions for determining respective values for a selected plurality of machine operation parameters;
- instructions for identifying a machine state based on the determined values of the selected plurality of machine operation parameters and calculating a gain value based on the identified machine state;
- and
- instructions for executing output torque control of the hydrostatic transmission via a closed loop control module and an open loop control module, wherein the closed loop control module applies the calculated gain value.
A machine for employing transmission output torque control, the machine comprising:
- a hydrostatic transmission;
- a plurality of user input elements operable by a machine user to affect the operation of the hydrostatic transmission;
- a measurement facility for determining respective values for a selected plurality of machine operation parameters;
- and
- a controller configured to identify a machine state based on the determined values of the selected plurality of machine operation parameters and calculate a gain value based on the identified machine state, and execute output torque control of the hydrostatic transmission via a closed loop control module and an open loop control module, wherein the closed loop control module applies the calculated gain value.
Dependencies are inferred from the claim text.