Wojciech Szynkiewicz

Rubik's cube as a benchmark validating MRROC++ as an implementation tool for service robot control systems

Purpose – This paper seeks to develop universal software (a programming framework) enabling the implementation of service robot controllers. The software should distinguish the hardware‐oriented part of the system from the task‐oriented one. Moreover, force, vision as well as other sensors should be taken into account. Multi‐effector systems have to be considered.Design/methodology/approach – The robot programming framework MRROC++ has been implemented as a hierarchical structure composed of processes, potentially consisting of threads. All of the software is written in an object‐oriented manner using C++ and is supervised by a QNX real‐time operating system. The framework has been verified on several systems executing diverse tasks. Here, a Rubiks cube puzzle‐solving system, consisting of two arms and utilizing force control and visual servos, is presented.Findings – The presented framework is well suited to tasks requiring two‐handed manipulation with force sensing, visual servoing and online construct...

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...

Mechatronic design of open-structure multi-robot controllers

Abstract The paper proposes a structure for open, hierarchical, multi-device controllers. The proposed structure takes into account that the system may contain several robots of different types, a certain number of cooperating devices, diverse sensors and also the fact that the task, the system has to execute, and the number and type of its components may vary considerably over time. The concept has been verified by designing a controller for a prototype Robot of a New Type (RNT) robot. The flexibility of the system is due to the software, so the programming aspect is treated comprehensively in the paper.

A prototype robot for polishing and milling large objects

The paper describes a prototype robot which due to its serial‐parallel structure exhibits, high stiffness and has a large work envelope. These features make this robot suitable for relatively high precision machining operations on large workpieces. The conroller for this robot was based on MRROC++, which is a robot programming framework. Thus the controller could be tailored to the tasks at hand, including the capability of in‐program switching of kinematic model parameters. To obtain those parameters for different locations in the work‐space a calibration procedure using linear measurement guides has been devised.

Control of two 5 d.o.f. robots manipulating a rigid object

The paper presents an open structure controller for a system consisting of several robots, cooperating devices and diverse sensors. This controller has been successfully used for the execution of tasks by two 5 d.o.f. (degree of freedom) robots equipped with sensors. When dealing with two robots having less than 6 d.o.f each and manipulating a rigid object, extra problems arise, because most of the trajectories expressed in six-dimensional task space are not admissible. A technique for computing the accessible positions for an object handled by two cooperating robot arms is developed. This technique can be incorporated into a motion planning algorithm for the dual-arm system. The motion planning problem is decomposed into two subproblems: first, an admissible path finding, and second, planning the trajectory along the given path. For the experimental verification of the method of generating and executing admissible trajectories the open structure multi-robot research-oriented controller (MRROC) was used. The paper presents how to build a controller tailored to the task at hand on the example of two robots transferring a rigid object.

Applications of MRROC++ robot programming framework

The paper concentrates on the way that the MRROC++ robot programming framework has been applied to produce control systems for robots of different types performing diverse tasks. Moreover, both a brief formal specification and the method of implementation of the MRROC ++ based system is presented.

Control Architecture for Sensor-Based Two-Handed Manipulation

In this paper we propose a sensor-based control architecture for two-handed robotic manipulation in a partially structured environment. We deal with two major aspects of sensor-based manipulation: visual localisation and recognition of objects and utilization of force and torque measurements. We also take into account that service robots should be endowed with reasoning capabilities about motions that have to executed and that high level operations must be translated into trajectories to be executed by the manipulators. As a benchmark task we chose the manipulation of Rubik’s cube.

A hierarchical CSP search for path planning of cooperating self-reconfigurable mobile fixtures

The paper presents the application of artificial intelligence tools for the path planning of complex multi-agent robotic systems. In particular, a solution is proposed to the planning problem for the conjoint operation of two or more mobile robotic fixtures used for the manufacturing of large workpieces, like those used in the aerospace industry. Such fixturing systems have been recently designed and tested, raising hopes to better satisfy the dynamic conditions of modern manufacturing, with its increasing emphasis on flexibility, adaptability, and automation. The proposed planning method is novel in two fundamental aspects. First, it interprets planning as a constraint satisfaction problem (CSP), rather than as a constrained optimisation, an approach ubiquitous in the path and motion planning literature. Secondly, the formulated CSP is solved by a hierarchy of incremental state space search algorithms which differ in some way from the existing state of the art. This hierarchy includes levels related to the robot and workpiece arrangement parameters and to three components of mobile fixture agents: a supporting head, a mobile base, and a parallel manipulator, respectively. Due to the use of CSP search, the planner constitutes a largely application-independent framework, on the basis of which specific industrial implementations can be defined by supplying the relevant physical, geometrical, and time-related constraints.

Nao Robot Navigation System Structure Development in an Agent-Based Architecture of the RAPP Platform

This paper focuses on the development of a navigation system structure for the Nao humanoid robot in an agent-oriented distributed architecture. The proposed navigation system is a part of the RAPP framework, a cloud based robotics platform. The RAPP framework is an open-source software platform to support the creation and delivery of robotic applications, which are expected to increase the versatility and utility of robots. All navigation tasks are defined and divided into separate components. The robot navigation system consists of a relative localisation based on Extended Kalman Filter (EKF) using both IMU and odometry measurements, visual QR-code based global localization, path planning, and motion control components. A proper allocation of navigation components, in the four-agent structure of the RAPP platform, is the main goal of this work. Navigation system components are implemented using Robot Operating System and Nao robot programming framework—NAOqi. Experimental results for the Nao robot are presented to show the validity of the proposed approach.

Reconfigurable control architecture for exploratory robots

Robots have to perform diverse and complex tasks. To face the limitations of the computational capabilities of robot on-board control computer, it is required to split the control systems between the robot embedded and the cloud computational resources. This paper presents a reconfigurable control architecture for a robot designed to meet this requirement. The embedded computer hosts a core agent, which provides the task-independent robot capabilities. The task dependent part called the dynamic agent is loaded from the cloud when required. The two mentioned agents execute the task, additionally utilising the capabilities of the cloud. Once the task is finished the dynamic agent is destroyed and the core agent awaits new user demands, upon which it reacts by downloading a new dynamic agent. Thus a reconfigurable system results, limited only by the resources provided by the cloud. The system is presented on an example of a humanoid robot exploring a home environment in search for hazards resulting from negligence of people suffering from mild dementia.