Patent ID: 8688274

Claim:
A robot positioning method, comprising: providing a robot, having a control unit, wherein an optical sensing device is disposed on a front end of the robot, and the optical sensing device has an optical sensing device coordinate system fixed thereon, wherein the optical sensing device comprises a lens and a charge coupled device (CCD), the CCD has an optical sensing surface and has an optical sensing surface coordinate system fixed on the optical sensing surface; providing a calibration plate, wherein multiple positioning marks are disposed on a surface of the plate, and the calibration plate has a calibration plate coordinate system fixed thereon; and performing a positioning step, comprising: capturing by the optical sensing device a calibration plate image; and according to the calibration plate image, calculating by the control unit a transformation matrix between the optical sensing device coordinate system and the calibration plate coordinate system and an optical sensing device-calibration plate coordinate value; wherein the step of calculating the transformation matrix comprises: capturing by the control unit a positioning mark-calibration plate coordinate value of each positioning mark in the calibration plate coordinate system; capturing by the control unit a positioning mark-optical sensing surface coordinate value of each positioning mark in the calibration plate image in the optical sensing surface coordinate system; and substituting by the control unit the positioning mark-calibration plate coordinate values, the positioning mark-optical sensing surface coordinate values, and a focal length value of the lens into a Bundle Adjustment formula, to calculate multiple matrix elements of the transformation matrix and the optical sensing device-calibration plate coordinate value, wherein the Bundle Adjustment formula is as follows: x a - x 0 = - f â¡ [ m 11 â¡ ( X A - X L ) + m 12 â¡ ( Y A - Y L ) + m 13 â¡ ( Z A - Z L ) m 31 â¡ ( X A - X L ) + m 32 â¡ ( Y A - Y L ) + m 33 â¡ ( Z A - Z L ) ] y a - y 0 = - f â¡ [ m 21 â¡ ( X A - X L ) + m 22 â¡ ( Y A - Y L ) + m 23 â¡ ( Z A - Z L ) m 31 â¡ ( X A - X L ) + m 32 â¡ ( Y A - Y L ) + m 33 â¡ ( Z A - Z L ) ] where x a and y a are the positioning mark-optical sensing surface coordinate value of the positioning mark in the optical sensing surface coordinate system, x 0 and y 0 are a projection center of the optical sensing surface coordinate system, m ij is the matrix element of the transformation matrix between the optical sensing device coordinate system and the calibration plate coordinate system, where i: 1 to 3 and j: 1 to 3 , X A , Y A , and Z A are the positioning mark-calibration plate coordinate value of the positioning mark in the calibration plate coordinate system, and X L , Y L and Z L are the optical sensing device-calibration plate coordinate value of the optical sensing device in the calibration plate coordinate system.