Th. Borangiu

Constraints-based motion planning for an automatic, flexible laser scanning robotized platform

The paper addresses an implementation issue of a robotized reverse engineering platform for not modelled objects. The RE platform is composed of three major components: a 6 d.o.f. industrial robot, a dual-camera laser scanner and a digitally controlled turntable on which the object is placed. One important objective of this work is to develop suitable scanning strategies and robot motion patterns for automatic sensor guiding and acquisition of 3D surface data of objects to be modelled. The proposed strategy implies the synchronization of the robot movements with the rotation of the turntable, in order to avoid collisions or axis out of range and to keep, if possible, the robot in the central area of its workspace. For each unique picture taking point, the adequate turntable angle and robot configuration will be computed. A 6 d.o.f vertical articulated robot simulator was developed to generate the set of necessary robot configurations and turntable angles corresponding to the scanning strategies. The simulator is used to test whether a scanning path is feasible from the kinematics point of view. The scanning strategy consists of two stages: first, predefined scanning paths are followed, based on offline planned motion patterns; secondly, evaluation of the acquired 3D data may eventually lead to new scanning paths with different orientations of the hand-held laser scanner to obtain complete 3D information of the hidden details of the objectpsilas surface.

Open architecture for robot controllers

The paper discusses a generic, open architecture for industrial or non-industrial robot controllers allowing system designers and robot manufacturers to develop rapid deployment automation solutions for particular mechanics of robot manipulators. The paper describes a multiple-axis open controller design for a mobile AGV platform carrying a robotic arm, with inclination control to provide horizontal alignment in any terrain configuration. The navigation and locating of the mobile robot platform, the motion control of the robotic arm, as well as monitoring, learning, program editing, debugging and execution are embedded in a multiprocessor system developed around a Motion Control solution for which a structured programming language was developed. A strongly coupled multi-processor architecture embedding model learning, control and man-machine GUI functionalities is described both as hardware implementing and basic software system design (RTOS, multitasking and operating modes). Experimental results are reported for the motion control of the 5-d.o.f. robot arm.

Intelligent Control Station for a Robot-Tended Adaptive Machine Tool

Abstract Intelligent manufacturing systems support a number of new functions, both for the real-time adaptive control of the machining process and for the supervision and control of the part and tool flow at cell level. The paper presents a method and implementation solution for the intelligent control of machine tools tended by industrial robots, integrated in a CIM environment. An adaptive extension of the CNC processor provides on-line optimisation of machine loading and batch productivity, with tool monitoring by means of a vision subsystem, integrated in a local supervision computer. The local supervisor links hierarchical feature-based representation of parts and tools with the on-line built process-knowledge data base, generating intelligent commands for the extended CNC system and for the robot controller.

Implementation of sequential function charts with microcontrollers

The paper describes an efficient method for process control using microcontrollers, based on logic control diagrams, that are commonly used by PLCs. The chosen software solution allows even quasi-simultaneous interpretation of several sequential function charts (SFC). The C compiler program CodeVision AVR was used for implementing this control solution on ATMEL microcontrollers from the ATMEGA family. The experimental results are described for the programming of a CNC machine using an ATMEGA microcontroller based circuit.

Open manufacturing control with agile reconfiguring of robot services

The paper describes a new, open control paradigm for discrete, repetitive shop floor production, designed as a solution for agile manufacturing reengineering through (a) multi-agent robot service reconfiguring and (b) implementing the robot service access model (RSAM) in a distributed, semi-heterarchical production planning, scheduling and execution control architecture. This distributed architecture integrates two layers with generic functionalities: (1) Dynamic reconfiguring of the resource (robot-vision) service access model RSAM through a multi-agent system organization; (2) Holonic manufacturing scheduling (robot allocation), control and tracking based on the PROSA holarchy and the Intelligent Product technology — implemented through intelligent embedded devices (acting as Active Holon Entities) which use OpenEmbedded Linux as real-time operating system. Experimental results are reported from production scenarios tested in the two shop-floor platforms of the Laboratories AIP-PRIMECA (University of Valenciennes) and CIMR (University Politehnica of Bucharest) composed by robot-vision workstations.

Remote control of a multirobot infrastructure for E-learning training sessions

The paper describes a scientific project aiming to build up an R&D collaboration portal and communication platform for robot integration in on demand, flexible manufacturing structures and hands-on team training. The project offer a solution to control remotely a fault tolerant robotized manufacturing cell. The platform is a software product designed to support multiple remote connections with a number of Adept Technology V+ robot-vision controllers (masters over manufacturing workstations), either located in a local network or via Internet. Additionally, allows the transfer of multiple captured pictures to an IBM xSeries server for high-speed, parallel processing of images according to existing or new algorithms (enhancement, feature extraction for part flow management, guidance vision for robots (GVR), and automated visual inspection (AVI) from measurements based on vision tools).

Integration of Machine Tools with Adaptive Control in Intelligent Manufacturing Systems

Abstract Intelligent manufacturing systems support a number of new functions, both for the real-time adaptive control of the machining process and for the supervision and control of the part and tool flow at the cell level. The paper presents a method and implementation solution for the intelligent control of machine tools tended by industrial robots, integrated in a CIM environment. An adaptive extension of the CNC processor provides on-line optimization of machine loading and batch productivity with tool monitoring by means of a machine vision subsystem, integrated in a local supervision computer. The local supervisor links hierarchical feature-based representation of parts and tools with the on-line built process-knowledge data base, generating intelligent commands for the NCAC and robot controllers.

G7.1: Biprocessor Configuration with Alternating Hierarchy for High Speed Process Control

Abstract The object of the paper is to present a biprocessor control configuration dedicated to high speed technological processes, such as electrical drives. In the proposed structure, a specialized asynchronous interface connects two INTEL 8085 microprocessors, the first of which performs the frequency control for two electric stepper motors, according to numerical two-axes interpolating algorithms, while the second works out the optimal controls (feedrate, speed) for a class of nonlinear performance indexes, subject to nonlinear constraints of inequality type.Any one of the two microprocessors, logically placed on priority based hierarchical levels, can take hold of the master position in the control system and communicate over an eight bit data bus with the subordinate processing unit (Slave). Real time processing diagrams are worked out, making therefore possible parallel high speed processing of both complex computing functions and of advanced optimization algorithms. Final remarks are made concerning some practical results, such as the improvement of contouring speed, productivity and cost of machining, in the computerized numerical-adaptive (CNC-AC) control of metal cutting processes.

Decentralizing Cloud Robot Services Through Edge Computing

The paper extends previous developments of cloud robot services for intelligent manufacturing with new data streaming and machine learning techniques that are used to dynamically reschedule resources and predict future behaviour on the shop floor. Data is obtained in real-time with edge computing solutions that ease the computing effort in the cloud, by moving intelligence to the edge of the manufacturing execution system. Thus, machine learning algorithms can be run in real-time context with re-training on new data; the insights become predictions, enabling real-time decisions for: operations scheduling, robot allocation and real status-based maintenance. Experiments are described.

LabView Based Control and Simulation of a Construction Robot

The paper describes a multiprocessor control system for construction robots integrated in a SOA designed as a layered CAD – CAE information structure. The motion control system addresses both the robot’s mobile carrier and the partially closed-loop arm of cylindrical type; their motion control is embedded in a multiprocessor Motion Control system for which programming library was developed. Experimental results concerning the motion control of the 5-d.o.f. robot arm are reported.