US 12,012,716 B2
Work machine
Yusuke Suzuki, Tsuchiura (JP); Hiroaki Tanaka, Kasumigaura (JP); Hisami Nakano, Tsuchiura (JP); Hiroshi Sakamoto, Kashiwa (JP); and Akihiro Narazaki, Tsukuba (JP)
Assigned to HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
Appl. No. 17/434,491
Filed by HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
PCT Filed Aug. 3, 2020, PCT No. PCT/JP2020/029704
§ 371(c)(1), (2) Date Mar. 18, 2022,
PCT Pub. No. WO2021/059749, PCT Pub. Date Apr. 1, 2021.
Claims priority of application No. 2019-174611 (JP), filed on Sep. 25, 2019.
Prior Publication US 2022/0220694 A1, Jul. 14, 2022
Int. Cl. E02F 3/43 (2006.01); E02F 3/32 (2006.01); E02F 9/20 (2006.01); E02F 9/22 (2006.01); E02F 9/26 (2006.01)
CPC E02F 3/435 (2013.01) [E02F 3/32 (2013.01); E02F 9/2203 (2013.01); E02F 9/262 (2013.01); E02F 9/2004 (2013.01); E02F 9/2225 (2013.01); E02F 9/2285 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A work machine comprising:
a machine body having a track structure and a swing structure attached to an upper portion of the track structure;
an articulated work device attached to the swing structure;
a plurality of actuators that operate the work device;
an operation lever that instructs each of the plurality of actuators on an operation according to an operator's operation; and
a controller configured to calculate a target velocity vector of the work device such that a position of the work device is maintained on a predetermined construction target surface or above an upper side thereof while the operation lever is operated, and perform an area restriction control of controlling at least one of the plurality of actuators such that the work device is operated according to the calculated target velocity vector,
wherein the controller is configured to calculate an operation velocity of the work device in a machine body coordinate system and a movement velocity of the machine body in a gravity coordinate system, and correct a direction of the calculated target velocity vector upward away from the construction target surface when occurrence of dragging is detected during execution of the area restriction control based on the calculated operation velocity of the work device and the calculated movement velocity of the machine body.