Yasumichi Aiyama

Pivoting: A new method of graspless manipulation of object by robot fingers

Graspless manipulation refers to operations in which a robot attempts to change the position and posture of an object without grasping it. Typical examples of graspless manipulation which have been studied so far are pushing and tumbling. This paper proposes a new method of graspless manipulation, pivoting, in which robot fingers maneuver an object in the same way that person moving furniture, as if an object walks on the floor by using appropriate vertices as virtual feet. This paper introduces the concept of this pivoting operation, describes its characteristics and analyzes it mathematically, points out the need for visual guidance for the precise performance of pivoting, and presents experiments with pivoting manipulation in connection with visual guidance.

Agile Assembly System by “Plug and Produce”

Abstract For highly flexible and agile assembly systems, installation of manufacturing devices is indispensable technology. In this paper, we propose a “Plug & Produce” concept. It is a methodology to introduce a new manufacturing device into a manufacturing system easily and quickly. It can also remove the device easily from the system. It is designed by analogy of Plug & Play concept in computer world. A holonic assembly system is installed using proposed Plug & Produce architecture. The validity of the proposed architecture is verified by experiments with robots and a belt conveyor. A robot will be installed to an existing cell in a short time. The proposed concept can enhance the agility of assembly systems greatly.

Holonic assembly system with Plug and Produce

Abstract An assembly system based on holonic concept has been newly installed. The system consists of three manipulators, one belt-conveyor and two warehouses. The system assembles several parts into a product. Its sequences are planned by negotiation among the assembly devices by means of contract net protocol. Thus, even though the parts are supplied at different warehouses, the system can generate a sequence of transportation automatically. Utilizing the characteristics of distributed autonomous systems, a new concept Plug and Produce is proposed. A device can be installed easily and then immediately start to work. This system has high robustness against the reconfiguration and sudden changes of products. Experiments were made for two kinds of assembly tasks and verified the efficiency of the system.

A holonic architecture for easy reconfiguration of robotic assembly systems

Proposes a flexible assembly system, where autonomous manufacturing devices and production management agents communicate with one another to accomplish production tasks. This architecture allows the system to arrange manufacturing devices independently of the type of products assembled and to assemble multiple products in parallel and asynchronous progress. This system also supports plug and produce, a system function that realizes easy reconfiguration. Thus, the system can return quick responses to breakdowns and changes in production quantities. This paper also presents an index for the general evaluation of reconfigurable manufacturing systems. With this index and the plug-and-produce function, the system can be reconfigured appropriately to adapt to changes in the manufacturing environments.

Cooperative transportation by two four-legged robots with implicit communication

Abstract In this paper, we show cooperative object transportation by two four-legged robots. To realize cooperative transportation with autonomy, we adopt implicit communication based cooperation. Each robot uses only its own sensors to estimate the state of a task. With this method, people can attend to the cooperation system without any changes. We will show an algorithm and two experiments; one is by two legged robots and the other is by one robot and a human.

Cooperative transport system with regrasping car-like mobile robots

This paper deals with motion planning of cooperative transfer with regrasping by a group of car-like mobile robots. In order to realize this transfer task by actual car-like robots, three aspects should be considered: the nonholonomic characteristic of car-like robots, how to control the force and avoid too large a force by position-controlled robots, and control cycle of the system. Based on algorithms from previous works, the authors propose the following approach: 1) designing robot hand mechanism; 2) constructing hybrid planning architecture composed of centralized and decentralized system including an object motion observer. A simple transport experiment by an actual robot system is made to show the effectiveness of this mechanism. Validity of the proposed method is verified by a transport simulation.

Planning of graspless manipulation by multiple robot fingers

Graspless manipulation is to manipulate objects without grasping by just pushing, tumbling and so on. One of the main difficulties in graspless manipulation is planning. To reduce the load of computation, we adopt a two-step approach: 1) construction and simplification of contact state graph at geometry level; and 2) planning of manipulation at mechanics levels. In this paper, we focus the latter and propose an algorithm to plan mechanically feasible manipulation. It generates digraphs that represent C-subspaces for all the contact states, and unites them into one big graph, which we call a manipulation-feasibility graph. The manipulation plan can be obtained by searching the graph. This algorithm is implemented for planar graspless manipulation by multiple robot fingers, and the planned results obtained are shown.

Cooperative transport with regrasping of torque-limited mobile robots

This paper deals with a motion planning of mobile robots during the cooperative transport of a large abject by a group of multiple mobile robots (a robot group). In spite of the complexity of the relationship between the several kinds of requirements for this problem, motion planning should be done in real time according to each robots torque limit to apply its force to the object. Based on the algorithm of Ota et al. (1995), the authors propose the following approach: (1) derive handling force applied to the object by each robot, and (2) determine the role for each robot (to handle the object or to regrasp it) by each robots torque limit and optimization of a penalty index indicating performance for obstacle avoidance, stable grasping, and reduction of force. Effectiveness of the proposed method is verified by a transferring simulation.

Tossing manipulation by 1 degree-of-freedom manipulator

There are some researches which perform complex manipulation tasks with low degree-of-freedom manipulator by sliding, rolling, releasing etc. They are called dynamic manipulation. In this paper, tossing manipulation is introduced as a form of dynamic manipulation. A 1-DOF manipulator swings its arm to roll/slide an object on it, and then tosses it to locate to goal position. This paper shows an analysis and a simulation of kinematic model of tossing manipulation. To locate an object to desired position, inverse problem is solved with various optimizations. Finally some experiments and their consideration are discussed.

Environmental support method for mobile robots using visual marks with memory storage

Presents a methodology of environmental support for autonomous mobile robots using visual marks with memory storage. The mark makes up for insufficient function of sensing and recognition; self-positioning, positioning of objects, and deciding methods to operate objects. The mark proposed in this paper consists of a landmark part and a memory part. The landmark part is used to estimate the relative position and orientation between robots and the mark, and the memory part gives information about what it is, what tasks there are, and how to conduct the tasks. Task execution using the marks with real robots is described to show the effectiveness of the proposed methodology.