Optimizing Welding Cycle with the Utilization of the IPS Tool

Abstract: A car body is one of the most significant part of a vehicle; known as Body-in-White, BiW, it impacts characteristics such as top speed, fuel consumption, safety and handling. In today’s industry most of the path planning is performed manually instead of automated offline programming, thus consuming more time and eliminates the opportunity of finding the most optimized path. A typical BiW consist of approximately 300 sheet metal parts that is joined by around 4000 weld spots. BiWs are usually pre-assembled into under-body, body sides, roof and body closures separately before assembled into a complete BiW. Therefore all the weld spots have to be distributed amongst a number of robots. The weld spots have to be distributed equally amongst every robot cells as well as robots to gain the most efficient welding cycles.
Collaboration between Fraunhofer-Chalmers Centre, FCC, and Swedish vehicle manufacturers such as Scania CV, Volvo Cars, Volvo Trucks, and Saab Automobile resulted in a support software called Industrial Path Solutions or IPS. Since the introduction of the IPS software several companies have manage to implement the software.
In a competitive vehicle manufacturing market, companies are driven to always look for new ways of improving the production line. Consequently, faster production rates results in having the capability to produce more product within same time frame as before the improvement. With a new cab under construction an opportunity has presented itself to optimize the production line and improve the production rate at Oskarshamn cab assembly factory.
Today, Scania uses Delmia V5 for programming and simulating welding cycle. Unfortunately Delmia lack the functionalities that exist in Industrial Path Solutions, IPS, such as sequencing, load balancing, line balancing etc. With the help of the mathematical analysis in IPS, welding cycle time compared to an experienced engineer has been proven to reduce with around 20%.
The thesis will be aimed at finding a more optimized path using simulations i.e. offline programming. This will be conducted with the help of a software tool called Industrial Path Solutions. By comparing the two different results a clearer insight on what the IPS actually optimizes. The most efficient welding cycle will depend on parameters such as cycle time, robot impacts and external impacts.