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 the 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 support future automated driving and parking vehicles.The proposed 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, conductive charging from the vehicle underbody and conductive 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 processes 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 an existing research prototype of a robotic automated 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 the operational integration of automated driving and parking cars and the automated charging system with the target to optimize the operational load of the charging infrastructure, e.g. in public parking areas. One main target of investigation represents the enhancement of user experience during the automated charging process. This includes the provision of smooth user interaction by a smart phone application and on-site interfaces, the guidance of the car to the right parking position, as well as provision of information about the actual charging status and billing data. In this way, the article introduces a comprehensive approach of automated robot-based charging of electric cars with the target to improve both user experience and the effectiveness of charging infrastructure utilization.