As the fraction of vehicles on the road that are electric increases, finding places to charge up away from home gets more complicated. Ideally, you want your car charging whenever it’s parked so that it’s always topped up, but in urban parking garages, typically just a few spaces (if any) are equipped for electric vehicle charging.
Ideally, the number of EV-friendly spaces would increase with demand, but wiring up a bajillion parking spaces with dedicated chargers isn’t likely to happen anytime soon. With that in mind, Volkswagen has come up with a concept for a way to charge any vehicle in a parking garage, using an autonomous mobile robot that can ferry battery packs around and plug them directly into your car.
After it is started via app or V2X communication, the mobile robot drives itself to the vehicle that needs charging and communicates with it. From opening the charging socket flap to connecting the plug to decoupling—the entire charging process occurs without any human interaction. The highlight: the mobile robot brings a trailer in the form of a mobile energy storage device to the vehicle and connects them; it then uses this energy storage device to charge the battery of the electric vehicle. The mobile energy storage device stays with the vehicle during the whole charging process. The robot, in the meantime, charges other electric vehicles. Once the charging service is complete, the robot collects the energy storage device and brings it back to the charging station.
While this is very obviously just a concept, it’s got some things going for it. Primarily, it’s easy to integrate into existing infrastructure, because you just need to map the garage once and then establish a comfy little home base for your new fleet of robots. From there, it’s straightforward to scale in both area and capacity. It’s also nice that most of the complicated and expensive robotics stuff (like sensors and brains) is all crammed into one unit, leaving the “battery wagons” completely passive, improving their reliability while lowering cost. It may take more than one of the 25 kWh battery wagons to charge a single vehicle, but that’s okay, because the robot has nothing better to do than shuffle them around.
The ambition underlying this concept is certainly worth appreciating, but it’s not entirely clear whether this is a problem that is necessarily best solved with a small fleet of mobile robots, as opposed to gradually building out more traditional EV charging infrastructure. Mobile robots like these are relatively complex and expensive, even if they’re constrained to operating in a parking garage. In theory, this level of autonomy is achievable, but in practice, any near-future deployment would likely require some level of human supervision: not only are there potentially tricky manipulation tasks that the robot needs to do, but the environment is only semi-structured (humans walking and driving through the garage add unpredictability), and all kinds of stuff can cause robot-unfriendly complications, from poor parking to litter.
Volkswagen seems to be imagining that this concept would be most useful when EVs are common enough that it would be impractical to assign them dedicated parking areas in a typical parking garage (where charging infrastructure could be concentrated). It’ll take more than just one car company to make that happen, but Volkswagen is doing its part, having just revised the timing of its production target of one million electric vehicles from 2025 to 2023.
For now, Volkswagen says that this concept “can be made into reality quite quickly, if the general conditions are right,” but they don’t say what those conditions actually are. “Makes technological and financial sense” is a condition that isn’t going to be met within the next couple years, although “desire for useful and cute robots” is a valid condition anytime.
Evan Ackerman is a senior editor at IEEE Spectrum. Since 2007, he has written over 6,000 articles on robotics and technology. He has a degree in Martian geology and is excellent at playing bagpipes.