Novel wireless power supply system for wireless communication devices in industrial automation systems

There have been considerable advances in low power, integration and micro-systems technologies, enabling wireless communication for very small, affordable, lightweight and high performance devices. These technologies are still mainly used for consumer and office applications, but significant advantages can be obtained by applying the technologies to new areas. One area of particular interest industrial is automation and control systems, such as robotics and factory automation. In this paper we discuss the main challenges involved with realizing a reliable, wireless, and energy autonomous communication system suited for industrial automation. Special emphasis is placed on providing an overview of suitable power supply possibilities and describing a novel magnetic medium frequency power supply concept enabling true wireless energy supply within cell-volumes of more than 100 m/sup 3/ with sufficiently small infrastructure. The novel resonant power supply concept uses medium frequencies (/spl sim/120 kHz) in a "coreless transformer", enabling the supply of devices within a certain volume, for example a production cell, surrounded by coils. By using omni-directional or rotating magnetic fields, together with three orthogonal receiver coils, it enables a shielding tolerant supply system with unique properties. Compared to primary battery technologies, the new approach offers approximately 50 times higher energy densities over the application lifetime.