Control system for work vehicle, control method, and work vehicle

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

• at least one sensor;
• an operating device including at least one operating member, the operating device being configured to generate at least one operation signal in response to an operation of the at least one operating member;
• and
• a controller including a memory and a processor, the controller being operatively connected to receive at least one detection signal from the at least one sensor and to receive the at least one operation signal from the operating device,
• the controller being programmed to
• control the work implement based on the at least one operation signal,
• use the at least one detection signal to obtain a distance between the work implement and a design terrain which represents a target shape of a work object,
• use the at least one operation signal to determine whether a leveling determination condition indicating that work performed by the work implement is leveling work is satisfied, and to determine whether a surface compaction determination condition indicating that work performed by the work implement is surface compaction work is satisfied, the surface compaction determination condition including a first surface compaction condition and a second surface compaction condition,
• determine whether to execute a leveling control in which the work implement is controlled so that the work implement moves along the design terrain, or to execute a surface compaction control in which the velocity of the work implement towards the design terrain is limited in response to the distance between the work implement and the design terrain,
• start the surface compaction control when the first surface compaction condition is satisfied,
• switch to the leveling control when the leveling determination condition is satisfied while the first surface compaction condition is satisfied and the second surface compaction condition is not satisfied, and
• maintain the surface compaction control when the leveling determination condition is satisfied while the second surface compaction condition is satisfied, the second surface compaction condition having been satisfied following a state in which the first surface compaction condition was satisfied.

A control method for a work vehicle including a work implement, at least one sensor, an operating device, and a controller programmed to control the work implement based on signals from the at least one sensor and the operating device, the method comprising:

• obtaining a distance between the work implement and a design terrain which represents a target shape of a work object based on the signals;
• determining whether a leveling determination condition indicating that the work performed by the work implement is leveling work is satisfied based on the signals;
• determining whether a surface compaction determination condition indicating that the work performed by the work implement is surface compaction work is satisfied based on the signals;
• executing a leveling control in which the work implement is controlled such that the work implement moves along the design terrain when the leveling determination condition is satisfied;
• executing a surface compaction control in which the velocity of the work implement toward the design terrain is limited in response to the distance between the work implement and the design terrain when the surface compaction determination condition is satisfied;
• and
• maintaining the surface compaction control when the leveling determination condition is satisfied while the surface compaction control is being executed.

A work vehicle comprising:

• a work implement;
• and
• a controller including a memory and a processor, the controller being programmed to
• execute a leveling control in which work implement is controlled such that the work implement moves along a design terrain indicating a target shape of a work object when a leveling determination condition is satisfied, the leveling determination condition indicating that the work performed by the work implement is leveling work,
• execute a surface compaction control in which the work implement is controlled such that a velocity of the work implement toward the design terrain is limited in response to a distance between the work implement and the design terrain when a surface compaction determination condition is satisfied, the surface compaction determination condition indicating that the work performed by the work implement is surface compaction work, and
• maintain the surface compaction control when the leveling determination condition is satisfied while the surface compaction control is being executed.