Patent ID: 11951637
Assignee: DELTA ELECTRONICS, INC.
Field: Handling (Mechanical engineering)
Classification: CPC B  G  Y | IPC B  G

Claim 8:
9. A calibration method for a coordinate system of a robotic arm, incorporated with a calibration apparatus comprising an alignment device, a robotic arm, a tool arranged on a flange on one end of the robotic arm and comprising a tool center point (TCP), and a processor electrically connected with the alignment device and the robotic arm, wherein the robotic arm uses a robot coordinate system, the flange uses an end-effector coordinate system, the tool uses a tool coordinate system, the alignment device uses an alignment device coordinate system, and the robotic arm and the alignment device are arranged individually, the calibration method comprising:
a) controlling the alignment device to capture an image in a Field of view (FoV), wherein the FoV is a three-dimensional space, the alignment device is immovable, and the alignment device coordinate system is fixed;
b) controlling the tool, by the processor, to move in the three-dimensional space generated by the alignment device under multiple gestures for performing a tool calibration procedure, wherein the processor records a first homogeneous matrix indicating a transforming relationship between the end-effector coordinate system and the robot coordinate system;
c) computing a second homogeneous matrix indicating a transforming relationship between the tool coordinate system and the end-effector coordinate system based on data obtained from the tool calibration procedure;
d) computing a third homogeneous matrix indicating a transforming relationship between the tool coordinate system and the robot coordinate system based on the first homogeneous matrix and the second homogeneous matrix, and computing the relative position of the TCP in the robot coordinate system according to the third homogeneous matrix;
e) controlling the TCP, by the processor, to perform a three-point fix procedure in the three-dimensional space for regarding points in the alignment device coordinate system as points of the TCP;
f) computing a fourth homogeneous matrix indicating a transforming relationship between the alignment device coordinate system and the robot coordinate system based on the third homogeneous matrix after the step e); and
g) computing relative positions of points in the alignment device coordinate system and in the robot coordinate system according to the fourth homogeneous matrix.