System and method for laser-based auto-alignment
AssigneeBeckman Coulter, Inc.
InventorStephen Otts
Life of this patent
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Abstract
In a laser-based alignment system, a laser sensor tool, comprising a laser emitter and detector element can be gripped by a gripper unit of a robotic arm and used to automatically align the robotic arm with a work surface. A landmark on the work surface can be identified by scanning the work surface with the laser sensor in an X-Y plane. A center point of the landmark in the X-Y plane can be determined to align the gripper unit with the work surface in the X-Y plane. The robotic arm can be calibrated on a Z-axis by moving the gripper downward in a z-direction until the gripper unit contacts the work surface.
Claims22
A method for auto-alignment, comprising:
- gripping a laser sensor tool by a gripper unit of a robotic arm, wherein the laser sensor is configured to emit a laser pulse and receive a reflection of the laser pulse;
- identifying a landmark on a work surface by scanning the work surface with the laser sensor in an X-Y plane;
- and
- determining a center point of the landmark in the X-Y plane to align the gripper unit with the work surface in the X-Y plane.
An assembly, comprising:
- a robotic arm, including a gripper unit configured to grip a laser sensor tool, wherein the robotic arm is configured to move in three dimensions over a work surface;
- an auto-alignment system, including one or more controllers coupled to the robotic arm and laser sensor, wherein the auto-alignment system is configured to instruct the robotic arm to grip the laser sensor tool, wherein the laser sensor is configured to emit a laser pulse and receive a reflection, and to move the robotic arm over the work surface in an X-Y plane;
- and
- wherein the auto-alignment system is further configured to instruct the laser sensor tool to scan the work surface to identify a landmark, and determine a center point of the landmark in the X-Y plane to align the robotic arm with the work surface in the X-Y plane.
A method of identifying a center point of a landmark, comprising:
- identifying a first set of boundary points of a landmark in a first direction;
- determining a first midpoint of the landmark in the first direction based on the first set of boundary points;
- identifying a second set of boundary points of the landmark in a second direction, substantially orthogonal to the first direction, wherein the second set of boundary points and the first midpoint are collinear;
- determining a second midpoint of the landmark in the second direction based on the second set of boundary points;
- and
- comparing a location of the first midpoint to a location of the second midpoint, and
- if the location of the first midpoint is within a predetermined distance of the second midpoint, calculating an average location and storing the average location, wherein the average location corresponds to a center point of the landmark;
- if the location of the first midpoint is not within the predetermined distance of the second midpoint, iteratively determining midpoints in alternating orthogonal directions, until locations of at least two midpoints are within the predetermined distance of each other.
Dependencies are inferred from the claim text.