System and method for electromagnetic pinning and hybrid control of a linear drive system
AssigneeRockwell Automation Technologies, Inc.
InventorsBrian M. Perreault, Yuhong Huang
Life of this patent
Estimating the term…
Abstract
A system and method for holding position of a mover in an independent cart system includes receiving a current feedback signal corresponding to a current present in at least one coil for a linear drive system in the independent cart system. A motion command for the mover is received, where the motion command defines a desired position along a track of the independent cart system to which the mover is to travel. An electromagnetic pinning control mode is disabled while controlling operation of the at least one mover to the desired position and enabled when the at least one mover is at the desired position.
Claims20
A method for holding position of a mover in an independent cart system, the method comprising the steps of:
- receiving a current feedback signal at a controller for the independent cart system in a physical reference frame, the current feedback signal corresponding to a current present in at least one coil for a linear drive system in the independent cart system;
- transforming the current feedback signal from the physical reference frame to a two-phase reference frame, wherein:
- a first phase of the two-phase reference frame corresponds to current providing a driving force to at least one mover along a track for the independent cart system;
- a second phase of the two-phase reference frame corresponds to current providing an attractive force between the at least one coil and the at least one mover;
- regulating the current in the first phase with the controller to drive the at least one mover to a desired position along the track in the independent cart system during a first operating mode;
- regulating the current in the second phase with the controller to a first level during the first operating mode;
- regulating the current in the first phase with the controller to hold the at least one mover at the desired position during a second operating mode;
- and
- regulating the current in the second phase to a second level, the second level greater than the first level during the second operating mode.
A system for holding position of a mover in an independent cart system, the system comprising:
- a track including a first drive member of a linear drive system;
- at least one mover including a second drive member of the linear drive system, wherein the first drive member and the second drive member operatively engage each other to drive the at least one mover along the track;
- and
- a controller configured to execute a series of instructions to:
- transform a current feedback signal, corresponding to a current present in the first drive member, from a physical reference frame to a two-phase reference frame,
- regulate the current present in the first drive member as represented by a first phase of the two-phase reference frame to drive the at least one mover to a desired position along the track during a first operating mode,
- regulate the current present in the first drive member as represented by a second phase of the two-phase reference frame to a first level during the first operating mode,
- regulate the current in the first phase to hold the at least one mover at the desired position during a second operating mode, and
- regulate the current in the second phase to a second level during the second operating mode, the second level greater than the first level.
A non-transitory computer-readable storage medium storing instructions for execution by a processor that, when executed, comprise the steps of:
- receiving a current feedback signal corresponding to a current present in at least one coil for a linear drive system in an independent cart system;
- transforming the current feedback signal from a physical reference frame to a two-phase reference frame, wherein:
- a first phase of the two-phase reference frame corresponds to current providing a driving force along a track for the independent cart system to at least one mover;
- a second phase of the two-phase reference frame corresponds to current providing an attractive force between the at least one coil and the at least one mover;
- receiving a motion command for the at least one mover to travel to a desired position along the track of the independent cart system;
- disabling an electromagnetic pinning control mode by regulating the current in the second phase to a first level while controlling operation of the at least one mover to the desired position;
- and
- enabling the electromagnetic pinning control mode by regulating the current in the second phase to a second level when the at least one mover is at the desired position, the second level greater than the first level.
Dependencies are inferred from the claim text.