True off-line programming based on second generation virtual robot technology.

Divic, A. ; Kohlmaier, M. ; Krappinger, R. 等

Abstract: Robotic manufacturing systems are widely used in industry. These systems are composed of many automated machines, industry robots and sensors. However since these systems are composed of many Robots, which share their workspace, they are very complex to be coordinated. In order to complete the production task accurately, optimized, without any collision and without interruption of production flow these systems must to be simulated. Nowadays manufacturing processes are supported commonly from the simulation models. This new technology of modelling guarantees a high accuracy finished tasks, optimized flow of production and coordination of all components and Robots too.

This paper describes briefly the use of the software tools to simulate and optimize the production process on the flexible manufacturing cell for the various parts. The software used on this research was RobotStudio.

Key words: Simulation, modelling, off-line programming, optimizing.

1. INTRODUCTION

One very difficult task of the manufacturing is coordination of movable resources in very tide shared areas at manufacturing plant. Coordination of industrial robots is a very difficult problem especially at the automotive industry. This task would take a very long time when we are trying to make that without support of computer. And the costs will be very high, if we trying to make that task on-line during interruption of productions. Due to the decreasing cost and increasing power of computers and due the rapid development of software tools, the virtual engineering and the simulation technology becomes most widely used technology for training, design and off-line programming. The three dimensional visualization capabilities of these tools is the primary reason why this advanced technology is becoming the interface of the future for computing. For specific application there are designed and developed special software tools.

The second aspect which deals this paper is the arc welding application. To achieve the high performance of the arc welding process is very importing to understand more about the thermodynamic process of collision between arc and workpiece. It is very important to choose appropriate arc welding parameters such are speed of the arc welding gun and weld, seams and weave parameter as well.

2. INTRODUCTION OF THE CASE STUDY

In order to introduce the power of new, revolutionary, simulation tool of ABB-RobotStudio and their Power Pacs, the arc welding application with several ABB industrial robots was chose. The case study is the flexible manufacturing cell which consists of four ABB Robots. The big Robot holds the workpiece and another three Robots performs the arc welding process. The Figure 1. extracted from RobotStudio shows exactly the Layout of arc welding cell.

[FIGURE 1 OMITTED]

3. INTRODUCTION OF THE SOFTWARE TOOLS

The software tool used for simulation, visualization and the off-line programming was RobotStudio. This tool was developed for the simulation of ABB robots and it is a very powerful tool for building a various scenarios for robots wrist paths. Using this tool enables the simulation analyst to take important decision about Layout planning, avoiding the collisions between a robot and surrounding and so on. RobotStudios kernel is built on the ABB Virtual Controller, an exact copy of the real software that runs a robot in production. It thus allows very realistic simulations to be performed, using real robot programs and configuration files identical to those used on the shop floor.

3.1 CAD Import

RobotStudio can import CAD Data easily in major CAD format like IGES, STEP, VRML, VDAFS, ACIS and CATIA. By working of this very exact data, the robot programmer is able to generate more robot programs, giving higher product quality.

3.2 AutoPath

This is one of the most time-saving features in RobotStudio. By using a CAD-model of the part to be processed, it is possible to automatically generate the robot positions needed to follow the curve in just a few minutes, a task that otherwise would take hours or maybe days.

3.3 Autoreach

Autoreach automatically analyses reachability and is a handy feature that let's you simple move the robot or the work piece around until all positions are reachable. This allows verifying and optimizing the layout of work cell.

3.4 Path optimization

RobotStudio can automatically detect and warn about programs that include motions in close vicinity to singularities, so that measures can be taken to avoid such conditions. Simulation Monitor is a visual tool for optimizing robot movement. Red lines indicate what targets you can improve to make the robot to move in the most effective way. It is possible to optimize TCP speed, acceleration, singularity or axes to gain cycle time.

3.5 Collision detection

Collision detection prevents costly damage to your equipment. By selecting objects concerned, RobotStudio will automatically monitor and indicate if they collide when a robot program executes.

3.6 Virtual FlexPendant

This is a graphical representation of the real flex pendant, powered by the VirtualRobot. Essentially everything that can be done on the real flex pendant can be done in the virtual flex pendant making this a great for the teaching or training tool.

3.7 True Upload and Download

Your whole robot program can be downloaded to the real system without any translation. This is a unique feature thanks VirtualRobot technology that technique only provided by ABB.

3.8 MultiMove

With RobotStudio 5, ABB takes its VirtualRobot technology to the next level. MultiMove is one new feature in RobotStudio 5 that's allowing the possibility to load multiple virtual controllers in one station. Another improvement is the MultiMove feature that enables a controller to run multiple robots.

4. ARC WELDING FOR ROBOTSTUDIO

PowerPacs are "plug ins" for the off-line programming system RobotStudio to optimize it for specific applications. ArcWeld PowerPac provides a number of strong features that makes it easier and more efficient to program arc welding robots off-line. ArcWeld PowerPac has been totally redesigned for the 5.0 release. A new Path View is introducing a totally new way of looking at a weld program. Instead of listing traditional program statements ArcWeld PowerPac is using icons and symbols to represent the weld program. Linking icons into a horizontal chain makes it possible to stack several paths in the Path View, which then creates a good overview for synchronized paths in a MultiMove system Figure 2.

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

ArcWeld PowerPac 5.0 is building on strong concepts introduced in earlier versions, such as paths, welds and templates. New concepts include part programs, setup and service procedures. All these concepts are introduced and neatly organized in the new ArcWeld Browser. Altogether ArcWeld PowerPac provides a number of strong features that makes it easier and more efficient to program arc welding robots off-line.

4.9 Path View

After opening the Path View, welds are added to the path using process and weld templates, combined with input from clicking at geometry objects in RobotStudio's graphics window. The instruction icons will immediately alarm the programer if a target is out of reach by changing the target color to red. If the target is within the reach of the robot, the target color will change to yellow. The path is tested and verified by pushing the play button in the Path Player. A successfully executed path will show all targets in green color. If the execution failed, it is possible to tune individual target position, orientation and other instruction attributes. Changes are checked by executing the path again. This procedure is repeated until all targets are tested and verified i.e. all targets in the Path View are green.

5. CONCLUSION

In this paper was introduced a great offline programming solution tool for robotized manufacturing systems. Offline programming reduce the risk by visualizing and confirming solutions and layouts before the actual robot is installed and generate higher part quality through creation of more accurate paths from CAD Data.

RobotStudio 5 is the leading product for offline programming on the market. With the new programming methods ABB is setting the standard for robot programming world wide.

6. REFERENCES

RobotStudio 5.06 .(2005) Users Guide, ABB Robotics Products AB, Article number: 3HAC025152-001, ABB Automation Technologies, ABB Robotics SE-721 68 Vasteras, Sweden

ArcWeld PowerPac 5.0 Users Guide, ABB Automation Technologies, ABB Robotics SE-721 68 Vasteras, Sweden

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Stopper, M. & Stuja, K. (2004). "Optimizing cycle time of flexible manufacturing cell using simulation software", Proceedings of the 11th International DAAAM Symposium, pp. 451-452, ISBN 3-901509-13-5, B. Katalinic (Ed.), October 2000, Opatija, Croatia

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