There are actually a couple of companies in Europe working with robotic gas pumps, and their systems work pretty much the same way.
First, you have to choose which pump to use, depending on which side your gas cap is on. Can't remember? No one can, apparently. Fuelmatics will give you a little sticker for the dashboard to help you out with that. Next, you have to prepay, just like most of us do now anyway. Fuelmatics uses either a screen at the pump, much like a drive-up ATM, or an app on your phone. Rotec Engineering's pumps in the Netherlands use an RFID sticker in the windshield that's tied to your account, so you have to preregister before filling up. While your information is being verified, the robot waits patiently near the fuel door.
Once the robots have determined that you're worth their time, the machine goes to work. A Dalek-like arm with a little suction cup on the end pops open the fuel door. The Rotec machines are a bit older, so another Dalek-like arm with a little claw spins the gas cap off. The Fuelmatics system takes advantage of the capless "flapper-like solution," as Corfitsen called it, that some auto manufacturers are using now. If your tank still has a cap, Fuelmatics will also give you a "speed fuel cap" that works with their machines. So generous.
Now it's time for the gas to get in the tank. In the Fuelmatics system, two cameras locate the exact location of the fuel pipe. "In an early generation, we used a microwave transponder," said Corfitsen. "It was too difficult for the motorist to get the transponder in the right position." No kidding. We can't even back the car up without a camera and colored guidelines on a screen anymore. In any case, once the machine finds the fuel pipe, it puts a spout in and starts filling the tank, just like a human would, but with less mess, and without smoking a cigarette at the same time.
When the sensors in the spout detect that the tank is full (or the app on your phone tells the system to stop), the spout withdraws and lets you know you're allowed to go now. The Dalek has spared your life ... this time.