Hysteresis compensation system
AssigneeBeckman Coulter, Inc.
InventorsMatt Briscoe, Rick Spencer, Jonn Hitch, Chad Buckles
Life of this patent
Estimating the term…
Abstract
A system and method for compensating for hysteresis in laboratory liquid handling apparatus. The system comprises a carriage holding a drive gear that meshes with and drives a gear rack. A hysteresis brake is also provided on the carriage and opposes the movement of the drive gear to provide continued positive engagement of the drive gear with the gear rack even when the system is static. When the direction of travel of the gear rack is reversed, the drive gear rotates an additional distance that compensates for the aggregate hysteresis found in the drive train.
Claims20
An automated liquid handling systems comprising:
- a. a gear rack;
- b. a chassis assembly having at least one drive gear operable to engage said gear rack;
- and
- c. at least one hysteresis brake engaging said gear rack operable to resist rotation, the hysteresis brake thereby maintaining positive engagement of the drive gear with the gear rack.
An apparatus for providing precision linear positioning of at least one laboratory pipette comprising:
- a. a rack;
- b. a drive mechanism having a drive component operable to engage a linear rack;
- c. a magnetic brake engaging the rack operable to provide a force opposing movement of the drive mechanism.
An apparatus for increasing precision in liquid handling systems comprising:
- a. a drive motor connected to a first gear;
- b. a rack in contact with said first gear;
- and
- c. a second gear equipped with a magnetic brake operable to provide a force opposing movement of the first gear.
A method for compensating for hysteresis in an automated laboratory device comprising the steps of:
- a. providing a drive gear that engages a gear rack;
- b. providing a motor in connection with said drive gear via a drive train;
- c. providing a hysteresis brake engaging said gear rack;
- d. moving the hysteresis brake such that resistance is provided to movement of the gear rack, thereby causing the drive gear to remain in positive engagement with the gear rack;
- and
- e. engaging the motor such that said drive train is positively engaged, causing said drive gear to move the gear rack in a first direction.
A method for reducing hysteresis in a mechanical drive system comprising:
- a. providing a drive train including a motor and a plurality of drive train components, the motor and drive train operable to move a driven component in a forward direction and a reverse direction;
- b. providing a hysteresis brake that resists movement of the drive train;
- c. calculating an error margin related to a distance of motor movement required to compensate for play between the drive train components when the direction of the driven component is reversed;
- d. receiving a requested direction of driven component travel and a requested distance of driven component travel;
- e. moving the motor a distance sufficient to drive driven component the requested distance of travel when the drive train components are in positive engagement;
- and
- f. causing the motor to move the distance related to the error margin if the requested direction of driven component travel is opposite a previous direction of driven component travel.
Dependencies are inferred from the claim text.