OEM&Lieferant Ausgabe 1/2020

85 of the position of the ground pad is crucial. Many companies that already offer inductive charging systems are looking for cost-effec- tive and reliable positioning systems. One obvious solution in this context is to use the cameras already available for other advanced driver assistance systems, in order to deter- mine the position of the vehicle relative to the ground pad. The engineers at ServiceXpert, with years of automotive experience along with in-depth knowledge of camera-based systems and em- bedded software development (especially AUTOSAR), have been able to develop an effi- cient, and a cost-effective pro- totype of a positioning system. The following lines depict a simple scenario while po- sitioning an automobile for inductive charging: As the automobile approaches the charging pad which is placed on the ground, the position- ing system guides the driver to follow a straight line in the direction of the charging pad. At a certain point, the charging pad is not visible from the au- tomobile and hence, the driver needs support from a posi- tioning system that aids him to park the vehicle exactly above the charging pad. Today, such systems do exist, these systems use various sensors and signals to aid in position- ing the automobile. However, current positioning systems have problems with range and interoperability with the different charging systems which in turn are affected by the characteristics of the ve- hicle and charging coil. In order to solve these chal- lenges for the optimal po- sitioning of the vehicle, the engineers at ServiceXpert have developed a unique, but simple solution that incorporates a stereo camera. A stereo camera functions like the eyes of a vehicle. With the camera’s aid, the vehicle’s system can see the vehicle’s surroundings, recognize objects and calculate the distance between these objects. It is also used to compute the position of the vehicle relative to the charging pad. In order to aid the process of positioning, the ground pad is provided with an optical positioning feature, which ensures easy rec- ognition by a standard camera. The camera then can provide information indispensable for the positioning process. As soon as the optical marker present on the ground pad is captured by the camera, the distance of the vehicle and the angle relative to the optical marker is calculated for each individual im- age generated by the camera. As soon as the ground pad is not in the field of view of the camera, an algorithm tracks the movement of the vehicle in relative to the last position. The information required to support the driver is shown on a display inside the vehicle. The driver receives a message to stop the vehicle as soon as the vehicle is within a predefined optimal range and a predetermined orienta- tion. For this system, the cameras of existing driver assistance systems only must be in- stalled on the vehicle in such a way that they recognize the ground pad at least once and thus the corresponding positioning algorithm can be “fed” with image data. Most of the inductive charging stations with higher charging power will have a wall base station in the future, a so-called “wall box” that controls and supplies the inductive ground pad. Communication between the two parties starts when the vehicle is within range of the wall box. As soon as the vehicle reaches the correct position above the ground pad, the vehicle sends the request for energy transfer in order to initiate the charging process. The wall box takes over the vehicle authentication, processes and online payment and then dis- plays the necessary information, such as the total energy units consumed. The prototype implemented by ServiceXpert was presented for the first time as part of the „Inductive Charging“ TechnologyDay by Zollner Elektronik AG on October 17, 2019. Among the participants were representatives from well- known automotive OEMs. The system pre- sented met with great interest among those present and proved to be very attractive, as there are no additional costs for installing new hardware in the vehicle. Visitors to the Technology Day were able to experience the position- ing system for themselves by parking the automobile above the ground pad with the help of an external display present on the center console of the automobile. For future development of the prototype developed by ServiceXpert, the connection to other sensors already avail- able in the vehicle along with existing vehicle operating data will be used in order to ensure more precise and sta- ble tracking of the movement. Also, the data calculated for a positioning system can also be used to support the driver support when parking and / or autonomous parking. Mr. Thomas Eiber, proj- ect manager for „Inductive Charging“ at Zollner Elek- tronikAG inZandt, whoworks closely with ServiceXpert on the project: „The agile way of working, the well-founded AUTOSAR know-how’s and the eye for cost-effective, practical solutions is what ServiceXpert is about and very much appreciated in de- velopment projects at Zollner.“ The team at ServiceXpert al- ways uses the current state of the art technology in the development and provision of intelligent solutions for complex mobility requirements and continuously builds up competencies and know-how in the con- text of technological change in the automo- tive industry. The use of a stereo camera for vehicle positioning during inductive charging offers a cost-effective, convenient solution in the area of electromobility. ServiceXpert GmbH  www.servicexpert.de/en/home Website