WIRELESS CHARGING
Autonomous wireless charging keeps robots running Buck-boost regulators efficiently power wireless charging stations for mobile robots.
LOGISTICS,
delivery and inspection industries increasingly rely on mobile robotic fleets. These fleets have become large enough that their users are trying to find ways of recharging them that don’t rely on human operators. One means of automating the robotic charging process is through use of equipment from WiBotic. The approach is to build wireless charging hardware into the robotic platform. The charging hardware sends the bot to a charging station when it senses the battery needs a charge. The bot positions itself near the charging station in a way that aligns transmitting and receiving coils for power transfer. The various possible configurations of ambulatory and flying robotic platforms complicate the design of the charging apparatus. Today, there are several ways of wirelessly charging batteries. The most common is inductive charging as is typical in cell phones. But inductive systems are only efficient when the antennas are extremely close. It’s tough to design robots and drones to position themselves accurately enough for reliable charging. Magnetic resonance charging offers more flexible positioning but has a relatively small sweet spot for maximum transfer efficiency. WiBotic technology incorporates both inductive and resonant systems via what’s called an Adaptive Matching system. It constantly monitors relative antenna position and dynamically adjusts both hardware and firmware parameters to maintain maximum eeworldonline.com | designworldonline.com
energy transfer efficiency across several centimeters of vertical, horizontal and angular offset. An embedded identification and communication system lets any robot charge from any station, even if the robots have different battery chemistries, voltages, and charging rates. APIs from WiBotic let computers on the same network as the transmitter monitor charging and set charging parameters. For example, operators might schedule robots for charging at their highest power level when they’re busy, but more slowly overnight to maximize battery lifespan. WiBotic chargers must carefully manage charging modes to optimize up-time while not degrading batteries through repetitive quick charges. This 10 • 2020
An aerial drone landing on a WiBotic charging pad. The WiBotic charging system automatically manages both inductive charging when the receiver sits close to the power transmitter and magnetic resonance charging for situations like this one where the receiver sits some distance from the power transmitter.
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