Increased production of PEMFCs face several challenges, including higher manufacturability at lower cost of essential fuel cell system components and increasing quantities to meet market demand. In addition, there is a need for automated end of line (EOL) testing as well as traceability and quality data collection. Solutions to these bottlenecks are sought by manufacturers of fuel cells for industrial mobile applications such as material handling and municipal vehicles. The EU-funded INLINE project addressed these challenges by redesigning the media supply unit (MSU) and the tank valve regulator of the fuel cell. Both components are currently difficult to manufacture and are perceived as bottlenecks in the production process. Based on these new designs, consortium members planned an integrated production line using simulation tools that enabled the evaluation of different layouts and part flow strategies in different production scenarios. This included methods for automated quality inspection to improve the EOL test and to ensure traceability of critical components, and improved scalability of the manufacturing process.
INLINE included all the manufacturing processes along the supply chain and created a design concept for the MSU. “It was mandatory to know exactly where the bottlenecks in the existing processes are, so that the improvements made in INLINE have the highest impact,” says project coordinator Daniela Kirchberger. Researchers developed several new technologies specifically for the fuel cell production process. They included a tool for simulating the existing manufacturing processes and integration of the newly developed fuel cell components and processes. Project partners also developed an endoscopic sensor to automate burr detection in the drill holes in the tank valves. “A collaborating robot moves the tank valve to the sensor. The benefits of this system are the fast inspection time, only 20 seconds per valve, and the decreasing scrap rate and at the same time 100 % quality control,” Kirchberger explains.
During the fabrication of the power box the assisted assembly station provides projection-based support for workers. The parallelisation of assembly steps through the collaborating robot lead to a reduction of assembly time of 50 %, and inline quality control for carrying out assembly steps is provided. A smart camera sensor supported the worker through a light-based feedback system during the assembly of the battery pack of the fuel cell system. The sensor prevents the worker from incorrect assembly of the single battery cells, which enhances safety for the worker and shortens cycle time. In addition, project partners integrated a prediction visualisation tool into the EOL test software of the whole fuel cell system. According to Kirchberger: “The software predicts the values of the various sensors and can inform the worker if the EOL test will fail or not. The worker can then stop the test and re-work a possible failed sensor. The tool works in real time and can immediately alert the worker if a problem occurs.” The INLINE project provides an excellent base for further enhancement in the production of fuel cell systems with the technologies developed resulting in a higher quality, shorter cycle time in assembly steps and decreasing costs in the production of fuel cell systems. “The developments were made for production of fuel cell systems for forklift trucks. However, these developments can also be adapted for the manufacturing of other fuel cell systems which are used in cars, trains and so on,” Kirchberger concludes.
INLINE, assisted assembly, endoscopic inspection, proton exchange membrane fuel cells, tank valve, end of line test, media supply unit, robot