US 12,073,672 B2
Determining when a portable key device is located on a front side or on a back side
Anders Sahlström, Stockholm (SE); Fredrik Einberg, Huddinge (SE); Mattias Haeger, Solna (SE); and Mats Cederblad, Sigtuna (SE)
Assigned to ASSA ABLOY AB, Stockholm (SE)
Appl. No. 18/009,272
Filed by ASSA ABLOY AB, Stockholm (SE)
PCT Filed Jun. 1, 2021, PCT No. PCT/EP2021/064696
§ 371(c)(1), (2) Date Dec. 8, 2022,
PCT Pub. No. WO2021/249832, PCT Pub. Date Dec. 16, 2021.
Claims priority of application No. 2050676-2 (SE), filed on Jun. 9, 2020.
Prior Publication US 2023/0222855 A1, Jul. 13, 2023
Int. Cl. G07C 9/00 (2020.01); G01S 13/76 (2006.01)
CPC G07C 9/00309 (2013.01) [G01S 13/765 (2013.01); G07C 2209/63 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for determining when a portable key device is located on a front side or on a back side in relation to a barrier secured by an electronic lock, the method being performed in a location determiner and comprising:
obtaining a channel impulse response, CIR, based on an impulse signal transmitted from the portable key device, the CIR being based on a plurality of samples of the impulse signal as received by at least one antenna being fixedly mounted in relation to the electronic lock; and
determining, based on the CIR, whether the portable key device is located on the front side or on the back side;
wherein obtaining the CIR comprises obtaining a first CIR from a first antenna and a second CIR from a second antenna and wherein determining is based on determining a difference between the first CIR and the second CIR over a measurement time period, wherein both the first antenna and the second antenna face the front side.