Abstract: Article position estimation system comprises: article movement recognition part; reference point recognition part; position information generation part; and article position estimation part. Article movement recognition part generates article movement information including time point when article is taken out by mobile body or time point when article placement is completed by mobile body. Reference point recognition part recognizes reference point and generates reference point recognition information including identification information according to recognized reference point, reference point recognition time point, and information related to recognized reference point. Position information generation part generates information related to position of mobile body at reference point recognition time point based on reference point recognition information.

Abstract: There is provided a three-dimensional object printing apparatus including a first robot supporting a head having a nozzle for discharging a liquid and changing a position and a posture of the head, a second robot supporting a three-dimensional workpiece and changing a position and a posture of the workpiece, a curing unit that emits energy to cure or solidify the liquid discharged from the head, and a maintenance unit that performs maintenance on the head. The first robot has a first base portion fixed to a base. The second robot has a second base portion fixed to the base. In a plan view of the base, a virtual line segment connecting the first base portion and the second base portion passes between the curing unit and the maintenance unit.

Abstract: There is provided a three-dimensional object printing apparatus including an imaging device fixed to a base and imaging an object located inside an imaging range, a first robot supporting a head having a nozzle for discharging a liquid and changing a position and a posture of the head, and a second robot supporting a three-dimensional workpiece and changes a position and a posture of the workpiece. The three-dimensional object printing apparatus performs a material feeding step of causing the second robot to move the workpiece from an outside to an inside of the imaging range, and a printing step of causing the head to discharge the liquid to the workpiece while at least one of the first robot and the second robot relatively moves the head and the workpiece inside the imaging range.