Electrical motor control for high performance hydraulic systems
AssigneeHusqvarna AB
InventorMasoud Varshosaz
Life of this patent
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Abstract
A control unit (150) for controlling a hydraulic system on a construction machine (100), where the hydraulic system comprises a hydraulic pump arrangement with an electric drive motor configured to drive a hydraulic pump at a controllable drive torque, wherein the control unit (150) is arranged to obtain a load pressure of at least one actuator in the hydraulic system, to convert the obtained load pressure into a corresponding torque, and to control the electric drive motor to generate the torque.
Claims19
A control unit for controlling a hydraulic system on a construction machine, wherein the hydraulic system comprises a hydraulic pump arrangement with an electric drive motor configured to drive a hydraulic pump at a controllable drive torque and/or controllable drive speed,
- wherein the control unit is arranged to obtain a load pressure of at least one actuator in the hydraulic system, to map the obtained load pressure to a target drive torque or a target drive speed based on a mapping between the load pressure and the target drive torque or the target drive speed, and to control the electric drive motor to generate the target drive torque or the target drive speed, and
- wherein the control unit is arranged to detect a type and/or identification of the hydraulic pump and to configure the mapping between the load pressure and the target drive torque or the target drive speed based on the pump type and/or identification.
A control unit for controlling a hydraulic system on a construction machine, wherein the hydraulic system comprises a hydraulic pump arrangement with an electric drive motor configured to drive a hydraulic pump at a controllable drive torque and/or controllable drive speed,
- wherein the control unit is arranged to obtain a load pressure of at least one actuator in the hydraulic system, to convert the obtained load pressure into a target drive torque or a target drive speed, and to control the electric drive motor to generate the target drive torque or the target drive speed,
- wherein the control unit is arranged to receive a signal from a pressure sensor arranged to measure an actual pump output pressure, and to verify that the actual pump output pressure is within an acceptable range from an expected pump output pressure resulting from the target drive torque or the target drive speed.
A control unit for controlling a hydraulic system on a construction machine, wherein the hydraulic system comprises a hydraulic pump arrangement with an electric drive motor configured to drive a hydraulic pump at a controllable drive torque and/or controllable drive speed,
- wherein the control unit is arranged to obtain a load pressure of at least one actuator in the hydraulic system, to convert the obtained load pressure into a target drive torque or a target drive speed, and to control the electric drive motor to generate the target drive torque or the target drive speed,
- wherein the load pressure is converted into the target drive torque or the target drive speed based on an analytical relationship between the load pressure and the target drive torque,
- wherein the analytical relationship between the load pressure and the target drive torque is given by
- T
- =
- V
- g
-
- P
- 20
-
- π
-
- η
- [
- Nm
- ]
- where Vg is a displacement per revolution of the pump in cm3 and η is a unitless hydraulic-mechanical efficiency parameter associated with the hydraulic pump arrangement, or
- wherein the analytical relationship between the load pressure and the target drive torque is given by
- T
- =
- V
- g
-
- P
- 20
-
- π
-
- η
- +
- d
-
- ω
- dt
-
- J
- [
- Nm
- ]
- where Vg is a displacement per revolution of the pump in cm3, η is a unitless hydraulic-mechanical efficiency parameter associated with the hydraulic pump arrangement, J is a sum of moments of inertia of the pump and the electric drive motor, and ω is a rotational velocity of an electric drive motor axle.
Dependencies are inferred from the claim text.