Shovel

1 . A shovel comprising:

a lower traveling body;

an upper swing body swingably mounted on the lower traveling body;

an attachment attached to the upper swing body; a hydraulic cylinder configured to drive the attachment;

a main pump configured to supply hydraulic oil to the hydraulic cylinder;

a direction switching valve configured to control a flow rate and a flow direction of the hydraulic oil supplied from the main pump to the hydraulic cylinder;

a pilot pump configured to supply a pilot pressure to the direction switching valve;

a hydraulic control valve provided in a pilot line between the pilot pump and the direction switching valve; and

processing circuitry configured to control, in accordance with a state of acceleration of the hydraulic cylinder, movement of the hydraulic cylinder to suppress vibration of the hydraulic cylinder caused by an operation input related to the hydraulic cylinder by detecting acceleration of the hydraulic cylinder, correcting an operation command for the hydraulic control valve based on a value obtained by multiplying the detected acceleration by a gain, the operation command being generated based on an operation input related to the hydraulic cylinder, and outputting the corrected operation command to the hydraulic control valve,

wherein the processing circuitry is configured to correct the operation command such that:

(i) an operation amount according to the corrected operation command is smaller than an operation amount corresponding to the operation command, in a period of an increase in the operation amount corresponding to the operation command and

(ii) the operation amount according to the corrected operation command is larger than the operation amount corresponding to the operation command, in a period of a decrease in the operation amount corresponding to the operation command.

2 . The shovel as claimed in claim 1 , wherein the processing circuitry is configured to control, in accordance with a state of the acceleration of the hydraulic cylinder, the movement of the hydraulic cylinder to suppress vibration of the hydraulic cylinder due to the operation input related to the hydraulic cylinder, regardless of whether or not the vibration of the hydraulic cylinder occurs.

3 . The shovel as claimed in claim 1 , wherein the processing circuitry is configured to control, in accordance with a state of the acceleration of the hydraulic cylinder, the movement of the hydraulic cylinder to suppress an overshoot or undershoot in thrust of the hydraulic cylinder with respect to the operation input related to the hydraulic cylinder.

4 . The shovel as claimed in claim 1 , wherein the processing circuitry is configured to adjust, in accordance with a state of the acceleration of the hydraulic cylinder, a transfer function from the operation input to thrust of the hydraulic cylinder to simulate an increase in a frictional force of the hydraulic cylinder depending on the acceleration of the hydraulic cylinder.

5 . The shovel as claimed in claim 4 , wherein the processing circuitry is configured to adjust, in accordance with the state of the acceleration of the hydraulic cylinder, the transfer function from the operation input to the thrust of the hydraulic cylinder such that a relationship between the operation input and the simulated frictional force approaches linearity.

6 . The shovel as claimed in claim 1 , wherein the processing circuitry is configured to control the movement of the hydraulic cylinder by using a state of the acceleration of the hydraulic cylinder as feedback to the operation input related to the hydraulic cylinder.

7 . The shovel as claimed in claim 1 , wherein the operation input is an input of an operation command for automatically operating the hydraulic cylinder.

8 . The shovel as claimed in claim 1 , wherein

the attachment includes a boom, an arm, and an end attachment, and

the hydraulic cylinder is a boom cylinder configured to drive the boom.

9 . The shovel as claimed in claim 1 , wherein the processing circuitry is further configured to correct the operation command such that (iii) a vibration opposite in phase to a vibration of thrust of the hydraulic cylinder is generated in an initial stage of a period in which the operation amount according to the operation command is constant between the period of the increase and the period of the decrease.

10 . The shovel as claimed in claim 1 , wherein the processing circuitry is further configured to correct the operation command such that (iii) a vibration opposite in phase to a vibration of thrust of the hydraulic cylinder is generated in (a) an initial stage of a period in which the operation amount according to the operation command is constant between the period of the increase and the period of the decrease and (b) an initial stage of a period in which the operation amount according to the operation command is zero after the period of the decrease.