Work machine control system, work machine, excavator control system, and work machine control method

1. A work machine control system that controls a work machine including a working unit with a working tool, the work machine control system comprising:

a position detection device that detects a position information item of the work machine;

a generation unit that obtains a position of the working unit based on the position information item detected by the position detection device and generates a target excavation ground shape information item indicating a target shape of an excavation target of the working unit from an information item of a target construction face indicating the target shape; and

a working unit control unit that performs an excavation control of controlling a velocity in a direction in which the working unit approaches the excavation target so that the velocity becomes equal to or less than a limitation velocity based on the target excavation ground shape information item acquired from the generation unit,

wherein when the working unit control unit is not able to acquire the target excavation ground shape information item during the excavation control, the working unit control unit continues the excavation control by using the target excavation ground shape information item obtained before a time point at which the working unit control unit is not able to acquire the target excavation ground shape information item.

2. The work machine control system according to claim 1 ,

wherein the working unit control unit stores the target excavation ground shape information item obtained before the time point at which the working unit control unit is not able to acquire the target excavation ground shape information item for a predetermined time, and

wherein the working unit control unit ends the excavation control being currently performed by ending the storage of the target excavation ground shape information item when the predetermined time elapses, the work machine travels, or a swing body to which the working unit is attached swings.

3. The work machine control system according to claim 2 , comprising:

a swing angle detection device that detects a swing angle of the swing body, and

wherein when the swing angle detected by the swing angle detection device is equal to or more than a predetermined magnitude, the working unit control unit ends the storage of the target excavation ground shape information item to end the excavation control being currently performed.

4. The work machine control system according to claim 2 ,

wherein the working unit control unit updates the stored target excavation ground shape information item by using an inclination angle detected by a device that obtains the inclination angle of the work machine.

5. The work machine control system according to claim 1 ,

wherein when the working unit control unit acquires the target excavation ground shape information item which is new before a predetermined time elapses, the working unit control unit starts the excavation control by using the acquired target excavation ground shape information item.

6. The work machine control system according to claim 2 ,

wherein when the working unit control unit acquires the target excavation ground shape information item which is new after ending the excavation control being currently performed, the working unit control unit starts the excavation control by using the acquired target excavation ground shape information item.

7. An excavator control system that controls a work machine including a working unit with a working tool, the excavator control system comprising:

a position detection device that detects a position information item of the work machine;

a generation unit that obtains a position of the working unit based on the position information item detected by the position detection device and generates a target excavation ground shape information item indicating a target shape of an excavation target of the working unit from an information item of a design face indicating the target shape; and

a working unit control unit that performs an excavation control of restraining the working unit from performing an excavation beyond the target shape based on the target excavation ground shape information item acquired from the generation unit,

wherein when the position detection device is not able to detect the position information item of the work machine during the excavation control, the working unit control unit continues the excavation control by storing the target excavation ground shape information item obtained before a time point at which the position information item is not able to be detected, for a predetermined time, and

wherein the working unit control unit ends the excavation control being currently performed by ending the storage of the target excavation ground shape information item when the predetermined time elapses, the working unit travels, or the working unit swings.

8. A work machine comprising:

the work machine control system according to claim 7 .

9. A work machine control method that controls a work machine including a working unit with a working tool, the work machine control method comprising:

detecting a position information item of the work machine;

obtaining a position of the working unit based on the detected position information item and generating a target excavation ground shape information item indicating a target shape of an excavation target of the working unit from an information item of a design face indicating the target shape; and

performing an excavation control of restraining the working unit from performing an excavation beyond the target shape based on the target excavation ground shape information item and, when the target excavation ground shape information item is not able to be acquired during the excavation control, continuing the excavation control by storing the target excavation ground shape information item obtained before a time point at which the target excavation ground shape information item is not able to be acquired, for a predetermined time.

10. A work machine comprising: control system that controls a work machine including a working unit with a working tool, the work machine control system comprising:

a position detection device that detects a position information item of the work machine;

a generation unit that obtains a position of the working unit based on the position information item detected by the position detection device and generates a target excavation ground shape information item indicating a target shape of an excavation target of the working unit from an information item of a target construction face indicating the target shape; and

a working unit control unit that performs an excavation control of controlling a velocity in a direction in which the working unit approaches the excavation target so that the velocity becomes equal to or less than a limitation velocity based on the target excavation ground shape information item acquired from the generation unit,

wherein when the working unit control unit is not able to acquire the target excavation ground shape information item during the excavation control, the working unit control unit continues the excavation control by using the target excavation ground shape information item obtained before a time point at which the working unit control unit is not able to acquire the target excavation ground shape information item.