| 摘要 |
PROBLEM TO BE SOLVED: To dispense with positioning between the detection axis of a gyro sensor and the turning shaft of an upper turning body.SOLUTION: Angular-velocity calculation means 12 executes coordinate conversion from a detection three-dimensional coordinate system defined by an X detection axis Xb, a Y detection axis Yb and a Z detection axis Zb into a reference three-dimensional coordinate system defined by a Z reference axis Zj agreeing with a turning shaft and an X reference axis Xj and a Y reference axis Yj intersecting mutually orthogonally on a plane orthogonal thereto, and thereby corrects deviation between the detection three-dimensional coordinate system and the reference three-dimensional coordinate system, and calculates the angular velocity ωzj around the Z reference axis Zj. |
