Nick Ivanescu

Holonic robot control for job shop assembly by dynamic simulation

The paper describes a holonic control solution for fault-tolerant job shop assembly with networked robots, based on the dynamic simulation of material processing and transportation. The designed holarchy considers the PROSA reference architecture, and was implemented by help of an object oriented step scheduler (off-line production planning, failure- and recovery management, and online production tracking) and OPC-based real-time PLC software integration (execution of order holons at batch level). Experimental results are reported as well as considerations about holarchy mapping on the computing architecture and future developments.

HOLONIC FAULT-TOLERANT CONTROL OF NETWORKED ROBOT-VISION ASSEMBLY STATIONS

Abstract The paper describes a networked fault-tolerant assembly system of job shop type containing multiple robotized stations operating under visual control. During the assembly process, the products are identified, located, qualified, and controlled by analyzing images from virtual cameras associated to stationary- and arm-mounted cameras. The holonic control architecture is formed by the following types of entities: a Global Assembly Scheduler generating Order Holons, a dual layer of Material Handling (Robot) Holons and Sensory Holons, and a System Monitoring & Database entity. These elements are embedded in a 3-layer computing & control structure, and interconnected by a 4-fold fault-tolerant communication network keeping track of assembly job execution. Implementing issues and experimental results are reported.

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.

A Distributed and Configurable Architecture for Controlling Industrial Processes

Abstract The paper presents a modern solution for supervising and controlling complex industrial processes, using an open and distributed architecture. Starting from a classical distributed control structure, a new software solution was developed, improving the capabilities of such a system with the capacity of interconnecting several classical distributed systems in a large control systems network. The software solution is based such a data base structure that allows an easy configuration of the control architecture. The result of this solution is a modular system consisting of several independent Remote Terminal Unit (RTU) that can be integrated in a single control system. In the final part, the paper presents a proposal for implementing specific functions in order to offer the possibility of remote supervising of industrial processes using Internet mechanisms.

Different Approaches Regarding the Operational Control of Production in a Flexible Manufacturing Cell

The chapter describes several modern solutions for controlling a complex manufacturing cell, consisting of conveyors, robots, stoppers and other devices, using one programmable logical controller (PLC). The objective was to design a control system for a Holonic Planned Manufacturing System running into an Intelligent Production Cell. In order to achieve this goal, each product processed in the manufacturing cell has to be identified and its own routing / workstation jobs schedule needs to be implemented without interfering with other products. Two solutions were implemented, one using an offline planner that calculates the necessary data for processing products on pallets and the other using Intelligent Electronic Devices (IED) attached to the pallets that can take decisions by themselves in real time. A special array of data structures was used to easily access and manage the pallets processed at the four robotized stations of the cell.

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).

INTERACTIVE LEARNING OF SCENE-ROBOT MODELS BASED ON AI TECHNIQUES

Abstract Intelligent image processing blurs the distinction between Guidance Vision for Robots (GVR) and Automated Visual Inspection (AVI) applications. The paper presents AI techniques for interactive learning of scene-object models by feature descriptions of part flows. Robot grippers are modelled by fingerprints for ***collision-free part access. The parameters of the vision models are remotely created by a Server application which accepts simultaneous connections over LAN/Internet with multiple Clients – executing on IBM PC robot terminals integrated in flexible, networked manufacturing structures. Experimental results are reported for cluster and pattern construction for part recognition.

MODERN SOLUTION FOR CONTROLLING A COMBINED FODDER PLANT

Abstract The paper presents a modern solution for controlling the industrial machines and the manufacturing process in a fodder producing factory. The automation system was chosen such as to allow correct control of whole plant without the need of a computer, using a single programmable logic controller (PLC). Also some interesting software solutions, for controlling some older devices that could not be replaced because of high cost, are presented. Production quality results and future development are also presented.

Robotized Flange Assembling with Line Scan Camera Control

Abstract The paper describes an intelligent manufacturing system which performs geometric control, manipulation and assembling circular flanges that arrive at high speed on a conveyor belt and are randomly positioned and oriented. The 2D image of incoming flanges is created from a number of line scans executed by a linear camera. A geometry inspection is carried out in real time based on visual measurements of the flanges holes. If the geometry test passed, the location data is transferred to a SCARA-type robot which mounts each of them on a 5-component assembly. A comparative performance analysis for two types of lighting devices is included in the paper.