Automated charging of electric cars for improving user experience and charging infrastructure utilization

The number of electric cars on the roads is steadily increasing and it is expected that
markets of battery-electric vehicles will experience an accelerated growth during the
upcoming years. One challenge for a successful employment of electric mobility represents the provision of sufficient charging points for large fleets. In this context, public charging systems play an essential role to provide access for a broad range of users. Standard technology today is manual charging by plug-in and plug-off the charging cables. This has drawbacks in view of safety, user comfort and limited access of persons with disabilities. In addition, cars are parked for a longer duration at charging stations so that they block access for other electric cars, and manual charging does not support future automated driving and parking vehicles.
This article introduces a selection of automated charging technologies for cars and
discusses their strengths and weaknesses for application in public areas. This includes
inductive charging, battery swapping, conductive charging from the vehicle underbody and conductive side-charging by use of standard connectors. Based on a value analysis, robot supported conductive charging by use of standard connectors is selected as the preferred solution for automated charging of private cars under consideration of investment costs, avoidance of specific vehicle adaptations and easy customer handling. The potentials of this technology to enhance existing charging infrastructure are discussed based on a research prototype of an automated robotic charging station. The discussion comprises aspects of charging system integration in urban and sub-urban infrastructure, operational boundary conditions as well as requirements for safe and reliable system usage. In addition, an outlook is given to an integration of self-driving and -parking cars in combination with automated charging systems with the target to optimize the operational load of the charging infrastructure, e.g., in public parking areas. User experience during automated charging processes can be enhanced by smart phone applications and on-site interfaces, guidance
of the car to the right parking position, as well as provision of information about charging status and billing.