US 11,655,612 B2
Work machine
Hiroaki Tanaka, Kasumigaura (JP); Hisami Nakano, Tsuchiura (JP); Yuusuke Suzuki, Tsuchiura (JP); and Hiroshi Sakamoto, Hitachi (JP)
Assigned to HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
Appl. No. 16/981,508
Filed by HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo (JP)
PCT Filed Jun. 13, 2019, PCT No. PCT/JP2019/023409
§ 371(c)(1), (2) Date Sep. 16, 2020,
PCT Pub. No. WO2020/049821, PCT Pub. Date Mar. 12, 2020.
Claims priority of application No. JP2018-166397 (JP), filed on Sep. 5, 2018.
Prior Publication US 2021/0115643 A1, Apr. 22, 2021
Int. Cl. E02F 3/43 (2006.01); B60K 35/00 (2006.01); E02F 3/32 (2006.01); E02F 9/26 (2006.01); E02F 9/20 (2006.01); E02F 9/22 (2006.01)
CPC E02F 3/435 (2013.01) [B60K 35/00 (2013.01); E02F 3/32 (2013.01); E02F 9/2004 (2013.01); E02F 9/2029 (2013.01); E02F 9/261 (2013.01); E02F 9/265 (2013.01); B60K 2370/152 (2019.05); B60K 2370/162 (2019.05); E02F 9/2246 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A work machine comprising:
a work implement having a boom, an arm and a bucket;
an operation device that gives an instruction to operate the work implement;
a controller that outputs an operation command to control operation of the work implement in accordance with an operation signal outputted from the operation device;
a construction-target determining device that outputs a designed surface; and
a bucket-position measuring device that measures a bucket-claw-tip position of the bucket, wherein
the work machine includes a load measuring device that measures a drive load of the work implement, and
the controller is configured to:
perform, in order for the bucket to excavate a ground according to the designed surface inputted from the construction-target determining device, a semi-automatic control by calculating a bucket-claw-tip target position and correcting the operation command, such that a velocity of the bucket is restricted more as a deviation between the designed surface and the bucket-claw-tip position measured by the bucket-position measuring device decreases;
acquire, when an excavation work is performed with the bucket, soil-nature information on a basis of the operation command, the bucket-claw-tip position outputted from the bucket-position measuring device, and the drive load outputted from the load measuring device, the soil nature information including a ground-surface height and a unit load which is a load per unit excavation depth;
generate a soil-nature map on a basis of the bucket-claw-tip position and the soil-nature information, the soil-nature map including a height map which indicates a relationship between the bucket-claw-tip position and the ground-surface height and a load map which indicates a relationship between the bucket-claw-tip position and the unit load;
calculate, when the semi-automatic control is performed, an estimated load that is an estimate of an excavation load on a basis of the height map of the soil-nature map, the load map of the soil-nature map, and the bucket-claw-tip target position; and
correct the operation command such that excavation force of the work implement increases as the estimated load increases.