US 12,449,435 B2
Methods and systems for picking and placing vessels and for aligning an instrument
Jon Lindquist, Coon Rapids, MN (US); Kevin Nowak, Waconia, MN (US); John Moyer, Delano, MN (US); Creigh Thompson, Chaska, MN (US); Steven Alseth, Cologne, MN (US); Nicholas Hofmann, Waconia, MN (US); Robert Torney, Chanhassen, MN (US); and Vladimir Goldman, Bloomington, MN (US)
Assigned to Beckman Coulter, Inc., Brea, CA (US)
Filed by Beckman Coulter, Inc., Brea, CA (US)
Filed on Jun. 25, 2021, as Appl. No. 17/358,830.
Application 17/358,830 is a continuation of application No. PCT/US2019/068809, filed on Dec. 27, 2019.
Claims priority of provisional application 62/786,112, filed on Dec. 28, 2018.
Prior Publication US 2021/0396773 A1, Dec. 23, 2021
Int. Cl. G01N 35/00 (2006.01); G01N 25/04 (2006.01); G01N 35/04 (2006.01)
CPC G01N 35/0099 (2013.01) [G01N 35/04 (2013.01); G01N 2035/0406 (2013.01); G01N 2035/0493 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of aligning a pick and place unit and a target, the method comprising:
a. providing the pick and place unit with a gripper assembly configured to move in a lateral direction and a vertical direction that is perpendicular to the lateral direction;
b. moving the gripper assembly in the vertical direction toward a first predetermined position with at least a first actuator, the first actuator comprising a stepper motor and an encoder;
c. determining if the target is located proximate the first predetermined position by performing acts comprising:
i. monitoring the first actuator for a first stalled position while moving the gripper assembly in the vertical direction, the first stalled position being detected by determining a slippage between the stepper motor and the encoder of the first actuator while moving the gripper assembly in the vertical direction
ii. determining if a presence of the target was detected or not detected by analyzing the first stalled position, wherein:
A. determining the target is present by detecting the slippage of the first stalled position is in a predetermined range, indicating the gripper assembly made physical contact with the target; and
B. determining the target is not present by detecting the slippage of the first stalled position is not in the predetermined range, indicating the gripper assembly missed the target;
d. if the presence of the target was not detected at the first predetermined position based on the first stalled position, then:
i. moving the gripper assembly toward a second predetermined position with at least the first actuator and a second actuator, the second predetermined position being offset in the lateral direction from the first predetermined position, the moving of the gripper assembly toward the second predetermined position including movement in the lateral direction by the second actuator and movement in the vertical direction by the first actuator;
ii. while moving the gripper assembly in the vertical direction toward the second predetermined position, monitoring the first actuator for stalling;
iii. determining a second stalled position of the gripper assembly when the first actuator stalls while moving the gripper assembly in the vertical direction and toward the second predetermined position; and
iv. determining if the presence of the target was detected or not detected by analyzing the second stalled position of the gripper assembly, wherein determining slippage between the stepper motor and the encoder comprises comparing a difference reported by the stepper motor and the encode.