Measurement of gaps and flushes in vehicle assembly

The Volkswagen Autoeuropa pilot will be demonstrated considering the process related with car alignment. The main goal for the demonstrator is that, through the data analytics results and the digital twin component, the not compliant products will be detected earlier in the production line and therefore reduce the number of products will need to be aligned. This objective is expected to be achieved by gathering data in order to correlate and predict process faults and thus allowing real time interventions in order to prevent the defects related to gap and flush and their propagation to down-stream processes

Pilot description

The pilot will focus on car alignment, which translates into ensuring the correct gaps and flushes values throughout the production process. The gap refers to the horizontal distance between the panels being measured, while the flush is related to the alignment of the two surfaces. The gap and flush measurements are carried out at several stages along the production line, to inspect the fitting and alignment between two surfaces, for instance to check the alignment of the tailgate or the correct assembly of the rear lights.
The main objective of the VWAE pilot is to correlate and predict process faults and thus allowing real time interventions in order to prevent the generation of defects related to gap and flush and their propagation to down-stream processes. Equipping the operators in the final assembly with measurement systems able to automatically collect data and analysing the data with those coming from the earlier automatic measurement stations of the body shop area, will allow a better control of the whole production process, by adapting the final assembly stations based on the complete set of data collected in previous processing stations. This will increase efficiency and reduce re-work by avoiding re-alignment operations, saving therefore time and reducing costs and waste.

Expected goals

Reduce the number of products needed to be aligned (-10%)

Improve the production costs avoiding alignment operations (-15%)

Improve the time that the operator needs to verify the product (-10%)

Problem definition

For a vehicle assembly line the main quality characteristic is the correct geometrical position of all assembled parts, such as the tail gate, the doors and the lights. The alignment of the car is not only important for aesthetic reasons but also for aerodynamics, thus having a significant impact on fuel efficiency or noise perception, as examples.
Therefore, these two controls are considered very important and mandatory from a quality point of view and for this reason they are measured at different stages of the process. For each stage, specific requirements are defined and strictly controlled. Currently, the gaps and flushes are measured automatically at several steps of the manufacturing process in the body shop area when the metal sheets are not painted yet, while in the assembly area they are measured at different stages, but manually by the operators.

Identified challenges

  • The amount of geometrical complexity and the demanding quality requirements requires a deep understanding of the data. The inclusion of pre-processing and analysis of data collected at several different stages, enabling the correct correlation of data at the multi-stage level and providing recommendations on the points to be checked, are the major challenge of Volkswagen Autoeuropa pilot.
  • Other significant challenge will be the introduction of a new portable, automatic measuring instrument to aid the operators in the gap and flush inspections at the assembly are, as well as allowing the automatic collection of these data, which were previously not recorded. This new instrument has to ensure a good ergonomics (easier handling and positioning of the instrument on the measurement locations), as well as, be compliant to industrial IT security standards.

Impact from openZDM technologies

Real time and early identification of deviations and trends, performed at local level, to prevent the generation of defects at single stage and their propagation; Non-destructive inspection (NDI) methods and data-driven quality assessment techniques; Implementation of a Digital Twin as key enabling technologies for online process simulation and adaptation.

Leading company

Volkswagen Autoeuropa (VWAE) is an automotive industry located in Portugal (Palmela) and a production plant of Volkswagen Group. It manufactures the Sharan and T-ROC models for VW and the Alhambra for Seat, another brand of the VW Group. Volkswagen Autoeuropa plays a strategic role in the Portuguese automotive industry, as it is the largest automotive manufacturing facility in the country and is responsible for around 10% of all Portuguese exportations. The plant employs around 6000 workers and, indirectly, it employs close to 10000 people through the more than 800 suppliers that provide materials, components and parts to the facility.
The plant is one of Europe’s most modern automotive production facilities. It was designed using advanced technology and continuous to incorporate the latest developments in automation and computerised production control, in order to meet the high standards required for manufacturing a quality product.