Programmable speed controllers and variable speed drives from Schneider Electric brands are ensuring passenger cabins on the London Eye are kept level and stable as the wheel rotates.
The construction of the London Eye is different to that of a traditional Ferris wheel, as the passenger cabins are mounted outside the big wheel, giving uninterrupted views over London. Each of the 32 cabins is mounted on two rings which are attached to the rim of the wheel. A motor controlled by a PLC system rotates the cabin within the rings to ensure the cabin remains horizontal at all times.
The wheel’s complete automation installation includes two Modicon Premium PLCs and two Monitor Pro supervisory systems mounted at ground level. Most of the control equipment, however, is mounted in the cabins themselves, each one being equipped with two Premium PLCs and two Altivar 58 variable speed drives. Data is exchanged between the ground-based and cabin-mounted equipment via a radio link, using the Modbus protocol.
In addition to controlling and stabilising the positions of the passenger cabins, products from the brands of Schneider Electric perform a range of other functions, designed to optimise passenger safety and comfort. The automation system, for example, controls cabin heating, air-conditioning and lighting, which are automatically adjusted as the wheel rotates, and also provides facilities for language selection on the multi-lingual commentary system.