Refueling robots are a specialized type of vehicle service robots. Refueling robots are designed to refuel a vehicle without human assistance. A refueling robot may be installed in the front, rear, or side of the vehicle. When you enter a gas station, you simply park your car near a gas pump, shut off the engine, and the refueling robot does the rest. The refueling robot reaches out and grasps the nozzle of the gasoline pump, and inserts the nozzle into your car. After the robot refuels your car, it puts the gas nozzle back on the gas pump. Then you can start your engine and leave. Several types of electronic payment systems are possible with refueling robots, you can pay for the gasoline without getting out of your car. If gasoline is replaced by hydrogen fuel, refueling robots would become more important, since hydrogen is more dangerous to handle than gasoline. Gasoline can be stored and pumped at normal atmospheric pressure, but hydrogen fuel is stored and pumped at high pressure, so using a robot to refuel a hydrogen-powered car would be safer than allowing a person to refuel it.