Work machine

A work machine comprising:

• a work implement that is attached to a machine body, and has a plurality of front implement members including a work tool;
• a plurality of actuators that drive the machine body and the plurality of front implement members;
• an operation device that operates the plurality of actuators;
• a posture sensor that senses postural data about the machine body and the work implement;
• an operation sensor that senses operation data about the operation device;
• and
• a controller configured to control the work implement by using excavation assistance control of controlling the work implement such that the work tool moves along a predetermined target excavation surface and deviation prevention control of preventing deviation of the work implement from a predetermined work area, having a boundary different from the target excavation surface, by decelerating or stopping operation of a subject front implement member, that is included in the plurality of front implement members, which causes the deviation of the work implement from the predetermined work area,
• wherein when the controller controls the work implement by using both the excavation assistance control and the deviation prevention control, the controller is configured to decelerate or stop the operation of the subject front implement member by the deviation prevention control when the subject front implement member is included in the plurality of front implement members controlled by the excavation assistance control, and based on a deceleration or stopping state of the operation of the subject front implement member, to operate a remaining front implement member excluding the subject front implement member from the plurality of front implement members thereby controlling the work implement such that an operation direction of the work tool approximates to an operation direction of the work tool that is to be generated when the work implement is controlled by using only the excavation assistance control,
• wherein the controller is configured to:
• compute, when the excavation assistance control is used, a target velocity related to at least two front implement members in the plurality of front implement members on a basis of the postural data and the operation data such that the work tool operates along the target excavation surface,
• compute, when the deviation prevention control is used, a limited velocity related to the subject front implement member on a basis of the postural data such that the work implement does not deviate from the work area,
• compute, when a target velocity related to the subject front implement member exceeds the limited velocity related to the subject front implement member, a limited velocity related to the remaining front implement member on a basis of the limited velocity related to the subject front implement member, and
• control operation of the at least two front implement members on a basis of the limited velocity related to the subject front implement member and the limited velocity related to the remaining front implement member.