WiBotic Secures US Approval for High Power Wireless Charging

Article By : Maurizio Di Paolo Emilio

WiBotic has obtained authorization from the U.S. FCC for its 300W high power transmitters and receivers for wireless charging of drones, mobile robots, and other commercial/industrial battery-powered devices operated in the U.S...

WiBotic has announced it obtained authorization from the Federal Communications Commission (FCC) for its 300W high power transmitters and receivers for wireless charging of drones, mobile robots, and other commercial/industrial battery-powered devices operated in the U.S. WiBotic is working to obtain other certificates allowing similar approvals of their products in other countries.

As Ben Waters, CEO of WiBotic, points out, this certification represents a transition point in the industry as, in the past, only low-power cell phone and high-power battery chargers for electric vehicles had been approved for such a widespread use. WiBotic’s technology allows drones and medium-sized robots to be recharged quickly, thus making it possible to use drone and robot technology for various industrial applications such as transport and safety.

“I think that the certifications play an important role because we help companies now quickly use an approved charging system that has a lot of unlimited use cases. And it is intended to work across a variety of charging requirements for different robots,” said Waters.

Wireless charging
Inductive coupling and MR (magnetic resonance) are the two methods being used by the most common Wireless Power Transfer systems. Each method has its strengths and weaknesses. WiBotic has attempted to get the best of both worlds by including both. Its patented Adaptive Impedance Matching system constantly monitors relative antenna position and dynamically adjusts both hardware and firmware parameters to maintain maximum efficiency.

The firmware allows users to monitor and set charging parameters. The onboard charger unit directly accesses the transmitter to perform the required functions. The system architecture allows for reduced downtime and overall maintenance costs.

FCC for WiBotic
The reliability of electrical charging systems is a fundamental prerequisite to greater device autonomy, with less human intervention and maintenance. WiBotic high-power wireless charging systems can charge a wide variety of robots, drones, and industrial automation equipment.

Automation-driven robots and drones are and will be increasingly faced with stricter safety and emissions regulations. “FCC approval allows us to meet the customers’ demand by providing standard products to a rapidly growing industry,” said Waters.

It’s difficult for robots and drones to achieve millimeter-level navigation accuracy to successfully dock for charging. With full power delivery within several centimeters from the transmitter, robots can connect to the power supply more easily with a wireless connection than with a contact-based connection, thus improving uptime. The software, equipped with dynamic tuning and charge scheduling algorithms, allows complete visualization of charging parameters and their optimized values, in order to increase system efficiency and substantially reduce maintenance costs over time.

WiBotic Drone Kit. Click to enlarge the image.

“FCC approval is a major achievement, representing thousands of hours of product development and testing,” Waters said. “Engineering of WiBotic’s projects to comply with FCC requirements has been a non-trivial task.”

The steps to apply for approval of a wireless charging system are similar to those required for a typical radio device. The difference lies in the radio frequency and power level used.

“In general, the three areas for which our system needs to be tested are safety, radiated emissions, and conducted emissions,” said Waters.

Safety is defined by SAR or specific absorption rate as in the case of cell phones.

SAR, which stands for Specific Absorption Rate, is defined as the amount of electromagnetic energy absorbed by the tissues of the human body in units of mass and is measured in W/Kg. High-frequency electromagnetic fields produce energy that is absorbed by human tissue and commonly dissipated in the form of heat.

Most wireless power systems use a very low frequency, which is why SAR does not represent a major challenge for the approval requirement. Just like a wireless cell phone charger the system is safe, even when dealing with robots.

As mentioned by Waters, the radiated emissions test is probably the most challenging one. He added that “radiated emissions are the harmonics of the frequency that we use for the power transfer. The systems generate harmonics just like any radio, so we’ll have multiples of that primary frequency. If those are above a certain threshold, then they could potentially interfere with other devices, so radiated emissions is sometimes called EMI.” Many tests under various conditions have been performed in order to meet the FCC requirements.

Measuring the conducted emissions produced by a device through its power cord requires proper instrumentation and well-defined test setup. Most standards require a measurement in a shielded chamber, using an impedance adapter, to decouple noise, and a measurement receiver that can measure the mean value and near peak value of the noise produced in the frequency range to be verified. The purpose of the conducted emission measurement is to check the noise related to the current coming out of the power supply cable of the object being tested. This noise propagates through the power supply network to which the object is connected, thus creating a large antenna that radiates noise; these propagating currents can therefore cause noise to the equipment connected to the network or nearby.

In terms of certification, the software is also important as it must be demonstrated the system properly meets all requirements according to the different modes of operation.

“Not only must we be able to demonstrate this, but we must also be able to set those settings appropriately,” said Waters.

Apart from wireless charging, there are evolving standards to prove robots comply with safety certificates. There is also an ISO standard for robot safety which is related to electrical safety guidelines that are largely governed by IEC, the world standard for electronics.

“These are quite challenging for robot companies because, just as in wireless charging, there are many requirements. Some of them are not related to electronics. They’re more related to the robots and the sensing and the software that the robots used to navigate. In fact, they’re quite different than what we’ve done for the FCC. They’re more related to just electronic safety in general,” said Waters.

Energy is a constantly challenging aspect.  As drones flights and robot use become more constant and repetitive, the use of flexible wireless charging stations offers a possibility for fast charging without interfering with operation. FCC approval can boost the entire wireless charging market and the robotics market by providing different robot solutions featuring wireless charging.

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