1. An article conveying robot system comprising: a conveyor adapted to convey a container having a plurality of containing cells where an article is positioned; a plurality of robot mechanical units positioned along a conveying direction of the conveyor; a plurality of robot controllers connected to each other by means of a communication part, each robot controller adapted to control respective robot mechanical unit; and a sensor positioned on the upstream side of the conveying direction of the conveyor relative to a robot mechanical unit on the most upstream side of the conveying direction, the sensor adapted to detect the position or position-orientation of the container conveyed by the conveyor and a containing state of the article in the container, the robot controller being adapted to activate the robot mechanical unit based on the detection result of the sensor so as to locate the article in the container, wherein: at least a robot controller corresponding to the robot mechanical unit on the most upstream side comprises an information managing part adapted to previously store the position or the position-orientation of each containing cell in the container and calculate containing cell information including the position or the position-orientation of each containing cell relative to the conveyor and the containing state of each containing cell, based on the stored position or position-orientation of the plurality of containing cells in the container, the position or the position-orientation of the container obtained by the sensor, and the containing state of the article, a robot controller corresponding to the robot mechanical unit other than the robot mechanical unit on the most upstream side comprises a receiving part adapted to receive the containing cell information from a robot controller of an adjacent robot mechanical unit on the upstream side, via the communication part, in synchronization with the conveying motion of the conveyor, a robot controller corresponding to the robot mechanical unit other than the robot mechanical unit on the most downstream side comprises a transmitting part adapted to transmit the containing cell information to a robot controller of an adjacent robot mechanical unit on the downstream side, via the communication part, in synchronization with the conveying motion of the conveyor, and each robot controller corresponding to each of the plurality of robot mechanical units comprises a controlling part adapted to control respective robot mechanical unit, based on the containing cell information, so as to locate an article in a containing cell in relation to the containing cell information when the containing cell is not occupied by an article.