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We address multiple-robot rearrangement problems in this paper. The rearrangement of multiple objects is a fundamental problem involved in numerous applications. In this case, it must be considered that a rearrangement task has constraints regarding the order of the start, grasping and finish time of transportation. Attention to these constraints makes it possible to rearrange rapidly; however, the calculation of the constraints is costly in terms of computation. In this paper, we propose a rearrangement method that calculates constraints efficiently. We analyze constraints and classify them into two groups: those that require less computational cost and those that require more. Robots do not calculate all groups at the same time — the time required for each type of calculation varies. The proposed method is tested in a simulated environment 96 times in six kinds of working environments with up to four mobile robots. Compared to the method that calculates all constraints at the same time, the robots' inactive time is significantly reduced and the total time for task completion is also eventually reduced. The proposed method is incomplete, but can be used to perform most rearrangement problems in a short time. [ABSTRACT FROM AUTHOR]

This paper offers a proposal for realizing the exploration and rearrangement of multiple unknown objects that lay scattered in working environments. The objective of the exploration task is to find all the objects in the environments. On the other hand, the objective of the rearrangement task is to carry all the objects to their goal position. Many applications are possible if the exploration and rearrangement tasks are combined. Some of them are cleaning, mine detecting and housework. An algorithm that integrates two tasks is presented with respect to the effectiveness of the path length and computational cost. In addition, an exploration algorithm is proposed that can work well in an environment that has many objects. In order to verify the algorithm, experiments are conducted with an actual robot. In the experimentals, an environmental recognition method is developed by attaching a mark to the objects. The robot recognizes the objects by finding the mark. It then obtains information from the mark. The mark is also used to modify the odometry error of the robot by computing its configuration relative to a mark attached to a wall. The success rate of this experiment was almost 80% in 20 trials. [ABSTRACT FROM AUTHOR]

Service robots are frequently fitted with end-effecters, which require high energy, to achieve a specific task. Robots require high-power energy sources that can meet several goals simultaneously. Given the technology of today, a battery-driven robot cannot work for long on a single charge. Todevelop a new powerful battery technology may take many years of exhaustive research. In this paper, we present a dual-energized scheme called HYbrid POwer Supply (HYPOS) that integrates the function of batteries and a household electric system to supply a robot. This technique can be realized by existing technology and is applicable to a variety of indoor applications. The challenge of implementing the HYPOS system is to develop the outlet-connection procedures and to handle the electric cord to reduce movement disturbance. We report on the prototype robot and the experiments that illustrate the effectiveness and practicality of this proposed system. The result has shown that the HYPOS system can supply a robot consecutively for almost 2 h and its efficiency is 73.6%, while the efficiency of a lead-acid battery is only 38.5%. [ABSTRACT FROM AUTHOR]

Abstract This study proposes a mechanism and a methodology for large force input to the environment by a mobile robot. To determine the limits on the force that a mobile robot can apply to a target object, we analyzed the forces between the robot, ground, and object, and the frictional-force limits between any two of these three bodies. To prevent the mobile robot from falling during the large-force application, the manipulator is connected to the robot via a passive rotational joint. This mechanism enables the mobile robot to search the environmental parameters. A new mobile robot fitted with the proposed mechanism, named ARODA, was developed. In a validation experiment, the developed mobile robot successfully tilted a relatively large and heavy object while searching the environmental parameters (the frictional coefficients of the floor and object and the size of the object). Equipped with the proposed mechanism, the mobile robot refrained from falling while applying a large force to the object by trial and error. Highlights • A mechanism for a mobile robot to apply a large force without falling is proposed. • The mobile robot with the proposed mechanism named ARODA is developed. • The ARODA successfully tilted a heavy object while searching the unknown parameters. [ABSTRACT FROM AUTHOR]