Hidehiro Yoshida

Dynamic control for robot-human collaboration

This paper proposes a new robotic system, which consists of multiple robots and executes a task in cooperation with humans. The authors consider a task in which the robots and humans manipulate an object in coordination. The authors assume that no interactions occur among robots and humans, that is, robots and humans have interactions with each other only through the object. The authors also assume that the humans are manipulating the object around a point fixed to the object. Under these assumptions, the authors design a controller for each robot around the point so that the object has a prescribed passive dynamics around the point. The stability of the resultant system is assured based on Popovs hyper stability theorem under the assumption that the passivity conditions for the humans are satisfied. The resultant control algorithm is applied to an experimental system, which consists of two industrial manipulators and a human. The results illustrate the proposed control algorithm.<<ETX>>

Manipulation of a flexible object by dual manipulators

Proposes a control algorithm of dual manipulators handling a flexible sheet metal. How to bend a sheet metal and how to manipulate the deformed sheet are discussed in this paper. First the authors derive the relation between the static deformation of the sheet metal and the bending moments exerted on the sheet using Lagranges equation based on a finite element model of the sheet. The authors then design a control algorithm by which the motion of the manipulated sheet is controlled using the resultant force applied to the sheet and the deformation of the sheet is controlled using the internal force applied to the sheet. Since the rigidity of the deformed sheet is not uniform, that is, the stiffness of the deformed sheet may depend on the direction along which the external force is applied, the authors cannot use the compliance of the flexible sheet for tasks having interactions between the sheet and its environment. The proposed control algorithm is designed so that the apparent impedance of the manipulated sheet metal is specified. The experimental results using industrial robots illustrate the validity of the proposed control system.

Manipulation of sheet metal by dual manipulators based on finite element model

Control algorithms of dual manipulators handling a flexible sheet metal is discussed in this paper. We consider two types of problems. One is the bending of a sheet metal, which is treated by a two-dimensional model, and the other is the twisting of a sheet metal where three dimensional deformation should be considered. In both cases, we derive the relation between the static deformation of the sheet metal and the bending and twisting moments exerted on the flexible sheet metal based on a finite element model. The experimental results using two industrial robots illustrates the validity of the proposed methods.