Control system for construction machine, construction machine, and method for controlling construction machine

1. A control system for a construction machine including a work machine including: a boom rotatable about a boom axis relative to a vehicle main body, an arm rotatable about an arm axis parallel to the boom axis relative to the boom, and a bucket rotatable about a bucket axis parallel to the arm axis and about a tilt axis perpendicular to the bucket axis relative to the arm, the control system comprising:

a first acquisition unit configured to acquire dimension data including a dimension of the boom, a dimension of the arm, and a dimension of the bucket;

a second acquisition unit configured to acquire external shape data of the bucket including contour dimensions of an external surface of the bucket and width dimensions of the bucket;

a third acquisition unit configured to acquire target excavation landform data indicating a target excavation landform that is a two-dimensional target shape of an excavation object on a work machine operation plane perpendicular to the bucket axis;

a fourth acquisition unit configured to acquire work machine angle data including a boom angle data indicating a turning angle of the boom about the boom axis, arm angle data indicating a turning angle of the arm about the arm axis, and a bucket angle data indicating a turning angle of the bucket about the bucket axis;

a fifth acquisition unit configured to acquire tilt angle data indicating a turning angle of the bucket about the tilt axis;

a calculation unit configured to obtain two-dimensional bucket data indicating an external shape of the bucket on the work machine operation plane on the basis of the dimension data, the external shape data, the work machine angle data, and the tilt angle data; and

a work machine control unit configured to control the work machine on the basis of the two-dimensional bucket data.

2. The control system for a construction machine according to claim 1 , wherein

the external shape data of the bucket includes first contour data including contour of an external surface of the bucket at one end in a width direction of the bucket and second contour data including the contour of the external surface of the bucket at another end in the width direction of the bucket, and

the calculation unit obtains the two-dimensional bucket data on the basis of the first contour data, a position of the work machine operation plane, and a position of a bucket blade edge.

3. The control system for a construction machine according to claim 1 , wherein

the two-dimensional bucket data includes bucket position data indicating a current position of the bucket on the work machine operation plane, and

the work machine control unit determines a speed limit according to a distance between the target excavation landform and the bucket on the basis of the target excavation landform data and the bucket position data, and limits a speed of the boom to be equal to or lower than the speed limit in a direction in which the work machine moves toward the target excavation landform.

4. The control system for a construction machine according to claim 1 , wherein

the two-dimensional bucket data includes bucket position data indicating a current position of the bucket on the work machine operation plane, and

the control system further comprises a display unit configured to display the target excavation landform data and the bucket position data.

5. A construction machine comprising:

a lower running body;

an upper swing body supported by the lower running body;

a work machine including a boom, an arm, and a bucket, and supported by the upper swing body; and

the control system according to claim 1 .

6. A method for controlling a construction machine including a work machine including: a boom rotatable about a boom axis relative to a vehicle main body, an arm rotatable about an arm axis parallel to the boom axis relative to the boom, and a bucket rotatable about a bucket axis parallel to the arm axis and about a tilt axis perpendicular to the bucket axis relative to the arm, the method comprising:

acquiring dimension data including a dimension of the boom, a dimension of the arm, and a dimension of the bucket;

acquiring external shape data of the bucket including contour dimensions of an external surface of the bucket and width dimensions of the bucket;

acquiring work machine angle data including a boom angle data indicating a turning angle of the boom about the boom axis, arm angle data indicating a turning angle of the arm about the arm axis, and a bucket angle data indicating a turning angle of the bucket about the bucket axis;

acquiring tilt angle data indicating a turning angle of the bucket about the tilt axis;

specifying target excavation landform data indicating a target excavation landform that is a two-dimensional target shape of an excavation object on a work machine operation plane perpendicular to the bucket axis;

obtaining two-dimensional bucket data indicating an external shape of the bucket on the work machine operation plane on the basis of the dimension data, the external shape data, the work machine angle data, and the tilt angle data; and

controlling the work machine on the basis of the two-dimensional bucket data.