WORK MACHINE

To provide a work machine capable of suppressing a reduction in measuring accuracy of GNSS positioning even when postures of a work device and an upper revolving body are changed during operation of the work machine.SOLUTION: A hydraulic shovel 1 comprises: a receiver 33 which calculates a position and an azimuth angle of an upper revolving body 3 on the basis of satellite signals received by two GNSS antennas 31 and 32; and a controller 38 which calculates the position of a tip of a bucket 8 on the basis of the position and the azimuth angle of the upper revolving body calculated by the receiver. The controller sets regions where the front work machine possibly obstructs reception of the satellite signals as mask regions 90 for each of the two GNSS antennas 31 and 32 on the basis of installation locations of the two GNSS antennas 31 and 32, a movable range of a front work machine 5, and an inclination angle and the azimuth angle of the upper revolving body. The receiver calculates the position and the azimuth angle of the upper revolving body on the basis of the satellite signals transmitted from satellites excluding those existing in the mask regions.SELECTED DRAWING: Figure 4 【課題】作業機械の作業中に作業装置や上部旋回体の姿勢が変化しても，ＧＮＳＳ測位の精度低下を抑制できる作業機械を提供すること。【解決手段】２つのＧＮＳＳアンテナ３１，３２で受信された衛星信号に基づいて上部旋回体３の位置と方位角を演算する受信機３３と，受信機で演算された上部旋回体の位置及び方位角とに基づいてバケット８の先端位置を演算するコントローラ３８とを油圧ショベル１に備える。コントローラは，２つのＧＮＳＳアンテナ３１，３２の設置位置と，フロント作業機５の可動範囲と，上部旋回体の傾斜角度及び方位角とに基づいて，２つのＧＮＳＳアンテナ３１，３２のそれぞれについてフロント作業機が衛星信号の受信の妨げとなり得る範囲をマスク範囲９０として設定する。受信機は，マスク範囲に位置する衛星を除いた残りの衛星から送信される衛星信号に基づいて上部旋回体の位置と方位角を演算する。【選択図】 図４