Control system for work vehicle, method and work vehicle

A control system for a work vehicle including a travel device and a work implement, the control system comprising:

• a controller configured to
• control the work implement according to a target value, the target value being a target soil amount,
• control the work implement so that a soil amount dug by the work implement coincides with the target soil amount,
• determine whether a slip of the travel device has occurred during control of the work implement, and
• change the target value according to a result of determination of the slip,
• the controller being configured to increase the target value upon determining that the slip has not occurred.

A method for controlling a work implement performed by a controller, the method comprising:

• determining a target design surface in accordance with a target value such that a distance from an as-built surface of a work target to the target design surface increases as the target value increases, the target design surface indicating a target trajectory of the work implement,
• controlling the work implement according to the target trajectory;
• determining whether a slip of a travel device has occurred during control of the work implement;
• and
• changing the target value according to a result of determination of the slip, the changing the target value including increasing the target value upon determining that the slip has not occurred.