M. Walęcki

Control and programming of a multi‐robot‐based reconfigurable fixture

Purpose – Machining fixtures must fit exactly the work piece to support it appropriately. Even slight change in the design of the work piece renders the costly fixture useless. Substitution of traditional fixtures by a programmable multi‐robot system supporting the work pieces requires a specific control system and a specific programming method enabling its quick reconfiguration. The purpose of this paper is to develop a novel approach to task planning (programming) of the reconfigurable fixture system.Design/methodology/approach – The multi‐robot control system has been designed following a formal approach based on the definition of the system structure in terms of agents and transition function definition of their behaviour. Thus, a modular system resulted, enabling software parameterisation. This facilitated the introduction of changes brought about by testing different variants of the mechanical structure of the system. A novel approach to task planning (programming) of the reconfigurable fixture syst...

Specification of a Multi-agent Robot-Based Reconfigurable Fixture Control System

The paper presents a formal specification of the control software of a reconfigurable fixture used for machining thin plates. The fixture is based on relocatable supporting robots. A multi-agent approach to control system structuring is used. The behaviour of agents is defined in terms of finite state automatons, transition functions, and terminal conditions.

Research Oriented Motor Controllers for Robotic Applications

Motor controllers are vital parts of robotic manipulators as well as their grippers. Typical, commercial motor controllers available on the market are developed to work with high level robot industrial controllers, hence their adaptation to work as a part of a scientific, experimental robotic system is problematic. The general concept of research oriented motor controllers for robotic systems is presented in this article as well as an exemplary gripper and manipulator application based on this concept.

Control system of a service robot's active head exemplified on visual servoing

The article presents approach to active head control systems development. It describes the system structure including motor drivers with low level position control, as well as high level control mechanisms running on a computer. The formal specification of this system is based on the agent approach. Finally, an exemplary implementation of the active head control system for visual servoing application is presented. Experiments conducted on the system confirm the adequacy of the approach.

Localization of Essential Door Features for Mobile Manipulation

In this paper, we present a control system of a robot actively detecting and labeling door features, such as handle, lock or door plate. System is described using agent-based approach, with clear division into control, effector and receptor subsystems, with most important parts deeply explained. Presented approach supplements gap between door detection and opening algorithms, giving a robot the ability to take more actions, like recognizing room number or opening door lock.

Motor Cascade Position Controllers for Service Oriented Manipulators

In the article a method is proposed to achieve some advantages of impedance control in the manipulators without direct torque controllers in joints, that is with indirect position–force control, position controlled joints and force–torque sensor in the wrist. The method is applicable to robots with backdrivable gears, where the external force exerted on the links causes the joints movement. The approach improves safety behaviour of a manipulator without the need for major changes in the hardware nor building a new robot, which is very important especially from the point of view of research systems.

Automated inspection of door parts based on fuzzy recognition system

The article presents a comprehensive strategy of door parts (locks, handles, doorplates etc.) examination as a paradigm of active sensing. It covers the whole process - from segmentation, through initial hypothesis generation based on fuzzy inference, to final recognition and precise localization of the keyholes in a robot base coordinate system. The strategy is a preliminary stage of a door locks opening procedure. The image analysis process is divided into three steps. First, an initial region of interest is localized using a RGB-D low resolution camera mounted on the robots head. It is then categorized, based on its properties, as a lock, handle, doorplate etc. Finally it is inspected using 2D camera mounted on the robots arm. Thanks to the preliminary localization with the head camera the robot can look at the point of interest at sight, without time-consuming thorough inspection of the whole door. The whole system was formally specified as an embodied agent. For that purpose a system modeling language was used to specify embodied agent subsystems behaviors. The proposed strategy is verified experimentally using Velma prototype service robot.

Multibehavioral position-force manipulator controller

In the article the whole process of a manipulator controller development is presented. The controller is designed for the execution of various benchmark tasks in the field of service robotics. Initially, a set of system behaviors is presented as the base of the universal controller structure. For that purpose the embodied agent theory and the System Modeling Language are utilized. The execution and switching between the behaviors relies on a particular algorithm. The control system is verified on a two arm robotic system that consists of position-controlled industrial manipulators and a number of extra force/torque sensors and cameras.