Robots are expected to expand their range of activities to human environment. Robots in human environment need redundancy for environmental adaptation. Furthermore, they have to automatically modify their controllers in response to varying conditions of the environment. Therefore, the authors have proposed a method to design a hyper-degrees-of-freedom (DOF) control system efficiently. The method decouples a large control system into small independent components called ldquofunction.rdquo Motion of the entire control system is expressed as superposition of multiple functions. Combination of some functions realizes many patterns of motion. Hence, various motions are realized with much smaller efforts on controller design. Additionally, the controller design is explicit since a controller and a function correspond directly. This paper expands the method to multi-DOF robots in 3-D space, since the conventional method was limited to a multirobot system in 1-D space. A new problem of interference among function-based systems occurs along with the expansion. A disturbance observer is applied on each actuator to eliminate the interference. Procedures of controller design under varying conditions are also shown. The proposed method is applied to a grasping manipulator with 18 DOF. Its experimental results show the validity of the method.

A Controller Design Method Based on Functionality

Design of a motion control system should take into account both the unconstrained motion performed without interaction with environment or another system, and the constrained motion where the system is in contact with environment or has certain functional interactions with another system. In this paper control systems design approach, based on siding mode methods, that allows selection of control for generic tasks as trajectory and/or force tracking as well as for systems that require maintaining some functional relation - like bilateral or multilateral systems, establishment of virtual relation among mobile robots or control of haptic systems - is presented. It is shown that all basic motion control problems - trajectory tracking, force control, hybrid position/force control scheme and the impedance control - can be treated in the same way while avoiding the structural change of the controller and guaranteeing stable behaviour of the system. In order to show applicability of the proposed techniques simulation and experimental results for high precision systems in microsystems assembly tasks and bilateral control systems are presented.

/pdf/smc-framework-in-motion-control-systems-2vilopbrxu.pdf

SMC framework in motion control systems

Decentralized control is a promising method with many advantages while an effective design method for it is desired. Design in conventional methods is complicated because the correspondence between a system role and its controllers is unclear. To solve this problem, we have proposed the idea of “functionality" for a bilateral control system. The idea is to divide the system role into minimum components. The design method based on this idea is clear since controllers correspond to respective functions. Furthermore, the design method is simple since each function is a minimum component. This study expands the idea of the functionality to design of decentralized control systems. Subsystems are constructed based on functions. Functions for normal operation and for exception handling are treated in a unified manner. The system can automatically sustain important functions by a priority order of functions. This method realizes simple and explicit controller design for a decentralized control system with exception handling. Simulation and experimental results show the flexibility, fault tolerance and expandability of the decentralized system.

A Controller Design Method of Decentralized Control System

Robots in human environment need some redundancy for adaptation. It is therefore necessary to solve a complicated design issue of large-scale systems with hyper-DOF. The authors have proposed a design framework of functionality to solve the issue. Although the framework deals with task shifts and exception handling in a unified manner, it was limited to a multi-robot system in one-dimensional space. This study expands the framework to multi-DOF robots in three-dimensional space and shows a developed form. Cooperative Jacobian matrix is introduced for coordinate transformation. A new problem of interactions among function-based systems occurs along with the expansion. Disturbance observer is applied on each actuator to eliminate the interactions. The simplicity and explicitness of function-based controller design carry on despite the expansion since function-based systems are decoupled with disturbance observer

/pdf/a-controller-design-method-based-on-functionality-ynh1pq5mg6.pdf

A controller design method based on functionality

Design of a motion control system should take into account (a) unconstrained motion performed without interaction with environment or other system, and (b) constrained motion with system in contact with environment or another system or has certain functional interaction with another system. Control in both cases can be formulated in terms of maintaining desired system configuration what makes essentially the same structure for common tasks: trajectory tracking, interaction force control, compliance control etc. It will be shown that the same design approach can be used for systems that maintain some functional relation - like bilateral or multilateral systems, relation among mobile robots or control of haptic systems.

/pdf/smc-based-bilateral-control-2cq42k8i2x.pdf

SMC Based Bilateral Control

Control architecture is an important problem for the distributed intelligent system. We describe on the evaluation of grouping with plural master cells for a cellular robotic system (CEBOT) as one of the group robotic systems. For the evaluation of the grouping, we use network energy as the estimation function, which we have proposed in a previous paper. By describing the grouping of the network with plural master cells as cores in a subnetwork, we represent the effect for the group structure of the organization or the society. Then for the estimation of the grouping of the network, which is organized by autonomous robotic units called "cells, " we propose the cross-dependence matrix in the cells. The matrix is led from the "task matrix, " which represents the relations between the cells and executing task steps. Finally, we show the simulation results for the example of the organized network by the cellular robotic system. This paper also describes mathematically the efficiency of grouping of the orgnization or the society.

加藤雄平

Papers

動的再構成可能ロボットシステムに関する研究 : 第10報, cebotの群構造に対するネットワーク・エネルギー評価を用いた組織の分散制御構造化

加藤 雄平

Papers

動的再構成可能ロボットシステムに関する研究 : 第10報, cebotの群構造に対するネットワーク・エネルギー評価を用いた組織の分散制御構造化

加藤雄平