Flexible interface tailored for robot development

This work aims to make an application with the primary objective of control and be able to schedule, in principle, a robot anthropomorphic six-axis, located in the workshops of the area of engineering of processes of manufacture of the University of Vigo. The followed methodology is the prior preparation of the implementation of communication with the own robot to subsequently install the application in a distributed manner.

Within the work carried out for the development and distributed control of a cell of production constituted by robot and lathe CNC in the Faculty of engineering, we have found the need for custom software application to be able to control the robot System Robot is available in the laboratory in the engineering area manufacturing processes in the Faculty of engineering.

As prerequisite has developed the DNC implementation [1] that it controls the CNC lathe and we have the need for the realization of the control of the robot to allow integration [2], [6] and to take control of information in a distributed mannertaking into account the implementation of new Internet-based technologies. In this work the main aim is the realization of an interface that allows comfortable handling and robot programming.

The industrial robot has been described as the most visible element of computer-assisted manufacturing and as the technical basis for greater automation of the production.

The development of the robots is closely related to the other technologies of manufacturing within the generic concept of CAM. [5] [7].

The robot System Robot RM10 [4] which will focus our study and development, has been acquired for the laboratory in the area of engineering of the processes of manufacture of the University of Vigo. Is of anthropomorphic type and has 6 degrees of freedom, by A.C. servo drives and load carrying capacity is 10 kg.

In the pilot phase is carried out a preliminary study for the identification and assessment of language or programming languages to be used, for the development of the working environment, as well as to solve the problem of communication with the system, since there was no information of any communications protocol used by the manufacturer. Originally an interface that simulates the control panel of the robot has been developed for which carried out the relevant measurements of the signal provided by the control via serial port via oscilloscope. Translated once map of signals that is obtained through the control panel has been the realization of the interface in the Visual Basic 6 development program. On the other hand it has needed make a parallel circuit to decide if the entry is well made by the panel of the Robot controller or from a computer. The development of the module of communications, via RS232, [3] has been required first to measure the speed and communication parameters.

Figure 1 reflects all the options that are in the control Panel of the robot, which have been used for the development of the new interface. A second interface decided to implement a number of improvements such as for example the management of these same instructions from your computer now using the keyboard to send signals by the easier handling for the user, use of keys in continuous format, reading the messages of response, programming, editing, loading and unloading of programs module. The application for the robot, requires security in industrial aspects and aspects of production quality by what application we must be allowed the administration of our tools in real time and the possibility of programming and implementation of programmes for which the following modules were developed in Delphi development programme: bi-directional communication ROBOT - PC, PC - ROBOT, configuration of the communication, the study of signal reception, movement of axes of the robot, programming of the robot, and administration in real time of the robot.

Figura1: Main screen of the operator panel

The implementation of the communication is based on a component developed in Delphi. Their behavior can highlight information receiving and sending data, as well as also the opening and closing of the serial port. Figure 2 shows the sending and reception of signals with the robot and the PC.

For the recognition of the Protocol of communication and the most significant values of the robot he had to perform a series of functions for the cleaning of information because data strings contained too many characters garbage and made it difficult to read such information.

Figure 2: Communication interface. PC-Robot

In the implementation of the module corresponding to the movement of the axis was essential to know the possible parameters that have to be set up before moving to the robot and its axes, so the study of signal collaborated in the making of the values of these parametersmanaging to jointly develop an interface which move the axes already configured, as illustrated in Figure 3.

Figure 3: Introduction of settings options.

"For the programming of the robot had to carry out a study of the functioning of each instruction based on the robot [4] user manual however was little information, so it had to develop a simulator with own rules syntactic and grammatical for the robot for which developed a so-called database""robot", in which there is a table "programs", where general information of the created programs and the location is stored. The table stores Detprogramas the sequence of instructions that contains a program, as well as the parameters used. The "Instructions" table contains the set of possible instructions in the robot and its syntax. The "move", without a doubt the most important table, contains the value of the configuration and points in a Cartesian plane of location of each axis.

For the programming of the robot were the following modules: creation of new programs, program loading from the robot and the PC, storage of programs in the robot and the PC, simulation of step by step execution, as well asthe programming of the robot (Figure 4).

Figure 4: Sample of programming screen. interactive.

The program example consisting of a series of previously stored and revised instructions. Then you can run this step by step program and when the user is in accordance with the required programming gets underway for an indefinite time.

A module of vital importance is the management of the robot in real time and this means that our application is able to move and execute commands by setting the robot for a possible start of process, movement or programming. (Figure 5). The module performs a series of shipments of instructions interpreting and shaping what the user wanted to do.

Finally, a very interesting module, is being conducted in phase of development, consisting of the idea to launch the application on an Intranet developed in Java with the basic movements of the robot in a distributed application.

Figure 5: Module for remote control of the robot.

After making stages corresponding to the development of the interface of the robot, and tune the operation of the aircraft, with all the functionality of the control in your own panel PC analyzes and determines the needs of programming and remote control in order to develop the working environment at the station. The application developed in Delphi presents to the user an easy to use environment-friendly to helping the understanding of the functions of the robot. The database set up for the robot stores information from the session initiated by the user and related to the administration of the robot to keep track of the various programmes, use or possible defects in the same. The robot to be administered from the PC processing instructions with a minimum delay time. It is said that it runs the instructions with a small delay almost insignificant.

As goals afterwards raised the debugging of distributed communication and integration with other applications developed that would allow access according to different geographical distributions. In our case would be reduced to a simulation of access from the classroom CAD/CAM in the area of engineering of the manufacturing processes, with communication to an application server, which would execute the implementation of control.

An automated system adjusts its operations in response to changes in external conditions in three phases: measurement, evaluation and control. The implementation of the robot includes the control stage. So it refers to the operations of measurement and evaluation requires specialized equipment like sensors specific, and can be incorporated as input signals in the card itself from entries from the robot and consequently in the programming of the robot and thusthey can be managed by the application.

In addition, the implemented application allows the development of the programming of the own robot friendly and can be performed in a practical way without needing to know the specific programming language of the RM10 Robot.

On the other hand, the application allows the ability to introduce additional improvements thanks to the modularity of the software with a view to be able to be extended to other types of devices or create module cell made up of different elements, in addition to the expansion of libraries to other types of robots and allow easy expansion of the application.

With regard to the technologies that form the structure of the distributed network we can mention that the same are making transactions in a world of web services. This application will allow the use of it for the development of utilities of remote control and distributed control in order to carry out an integrated manufacturing system based on web in the future.

[1] Alonso, J.A. Pereira, a. Diéguez, J.L development of a DNC implementation for numerical control Fagor 8050 and 8030.
[2] Chang Hsin-Chi, Lu Wen F, 1999, WWW-Based Collaborative System for Integrated Design and Manufacturing, Concurrent Engineering: Research and Applications
[3] EIA232E - Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, Electronic Industries Association.
[4] Industries LANBI, first start-up instructions, 1995.
[5] Manual Mitsubishi Industrial Micro robot System. Model VR-M1. BFP-A5191EB.
[6] To Paul Rodgers, Husor Avon P, Caldwell Nicholas H.M, 1999, Design Support Using Distributed Web-Based AI Tool, Research in Engineering Design.
[7] Ulrich Feth, Robot Simulation and Off-Line Programming Software, 1997.