Validation and Comparison of Alignment Methodologies for the SAE Wireless Power Transfer, J2954 Standard

Wireless Power Transfer (WPT) is set to become an alternative to conductive charging and promises highly efficient charging of electric and plug-in-hybrid vehicles based on the previous publications of the SAE J2954 standards. However, a single common methodology for alignment of the Vehicle Assembly (VA) to the Ground Assembly (GA) for wireless charging public infrastructure was not included in the first two versions of the SAE J2954 standard. Two methodologies for alignment are evaluated in this technical paper for a future SAE J2954 standard: Differential Inductive Positioning System (DIPS) using an auxiliary magnetic field to align; and Ultra-Wide Band (UWB) Ranging using Radio Frequency triangulation to align. Data and comparison of the two alignment methodologies are shown in conjunction with analysis and input from the SAE J2954 WPT Taskforce. The objective is to show the benefits and shortcomings of each technology based on testing and to indicate a harmonized decision for one methodology to be published in the next version of the SAE J2954 standard. This test report documents the results of two SAE J2954 Alignment Witness Tests of the Differential Inductive Positioning System (DIPS) performed in Stuttgart, Germany in September 2023 and Ultra-Wide Band Ranging Positioning System (UWB) performed in Switzerland in October 2023.