Flexible charging of electric vehicles with robots

In Hall 2 at Stand A10 of the Lower Saxony Ministry of Science and Culture, researchers from the Plan-Based Robot Control department of DFKI Lower Saxony will be presenting an original concept for charging electric vehicles.

In the ChargePal project, mobile charging robots are equipped with high-performance batteries, which they transport and connect to electric vehicles. Once charging is complete, the batteries are picked up again by the robots. Compared to conventional, static charging stations, a mobile charging robot can supply several vehicles without the need for extra charging parking spaces. The robot comes to the car and not the car to the charging station.

The key point is that, as in the normal case, charging takes place without the owner of the vehicle being present, but once charging is complete, the car does not block the charging option for others. Since in practice direct access to the charging socket on the car is not possible without the owner, ChargePal places inexpensive adapter columns between the car and the robot, to which the car is connected when parked and to which the robot later plugs in the battery.

A robot-assisted approach like the one in ChargePal could make it easier to upgrade existing properties and public parking spaces for e-mobility and expand the charging infrastructure.

One of DFKI's responsibilities in ChargePal is to ensure that the robot arm can insert the plug into the socket. Controlling the arm is difficult because the target position of the plug in the socket can never be precisely estimated in advance. These estimation errors increase the contact forces acting during insertion, which need to be compensated for. The researchers are also working on the planning and control of a fleet of charging robots. With several robots, each one must know exactly which battery it has to bring to which car and when.