The development of electric vehicles is gathering speed. China has set itself and car manufacturers ambitious targets, and aims for 12 per cent of all vehicles to be electric by 2020. France wants all cars sold after 2040 to be electric. Volvo has announced its intention to end the production of vehicles powered by internal combustion engine in 2019. The London Taxi Company has also signalled its intention to enter the electric vehicle market by changing its name to the London Electric Vehicle Company. The new taxis will have the same classic look as their predecessors, but will be cleaner and quieter. The UK government has recognised the shift towards electric vehicles, and in July 2017 announced a major investment programme to develop battery technology.
The pilot project Automated Module-to-pack Pilot Line for Industrial Innovation, or AMPLiFII for short, is demonstrating how efficient automation can contribute to the competitive production of traction batteries in Europe.
Within the AMPLiFII pilot battery assembly line, special purpose machine builder and system integrator Horizon Instruments has developed a high-speed cell picker system. This presented a unique challenge for Technical Director Daniel Bolton and his team. When designing the battery module production line they faced several technical and practical constraints: “We had a relatively confined space in which to fit the equipment and strict budget parameters, as well as a lead-in time of just seven months. We also needed to find a way of electrically testing each cell, rotating cells when needed and placing them into each module extremely precisely and at great speed.” One of the core tasks of the pilot plant is the simultaneous testing of groups of 30 cells for current and voltage before they are picked and placed in the battery modules. The high costs and space constraints meant that it was not possible to accommodate 30 individual battery testers. A solution had to be found. Together with the research and education group WMG at the University of Warwick, Horizon Instruments developed a bespoke multiplexer interface which allowed a single battery tester to be used. This not only delivered savings on space and capital cost, but also enabled the collation of comparative data regarding test status.
After testing, the battery cells are aligned accurately and inverted if necessary. The pick and place system then inserts them into the module located on a conveyor. The plant can be configured to handle the exact number of battery cells, which can sometimes vary. 100 individual cells per module is typical, with a total weight of approximately 9 kg once assembled. Festo delivered a compact complete solution using Cartesian robot technology for fast and precise handling. “We didn’t need to coordinate multiple suppliers or worry about product compatibility”, explains Daniel Bolton. “Within just eight weeks of the order being placed we had a custom system. Festo also provided us with technical support throughout the design, installation and commissioning process.” With the new automation solution, each cell can be picked, rotated, aligned and placed in the modules within 1.2 seconds.