Method for assisting in determining the position of an identifier in relation to a vehicle
First Claim
1. A method for assisting in determining a position of an identifier for accessing and starting a vehicle, in relation to said vehicle, the method comprising:
- transmission, from a first device from among the vehicle and the identifier, to a second device, separate from the first, from among the vehicle and the identifier, at a transmission time t0, of an initial train of N sinusoidal signals, with identical amplitudes and with respective frequencies fp, pϵ
[1;
N], such that, for all values of p between 1 and N−
1;
reception, by the second device, of an image train corresponding to the initial train altered by the transmission,construction of a frequency spectrum of the image train,an inverse Fourier transform of the spectrum to obtain a temporal signaturea first integration of the temporal signature, between the transmission time and a predetermined intermediate time tint, to obtain a first resulta second integration of the temporal signature, between the intermediate time and a predetermined final time tf, to obtain a second result, andcomparison of a ratio of the first result to the second result with a threshold value, to determine whether the identifier is positioned inside the vehicle.
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Accused Products
Abstract
The invention relates to a method (METH) for assisting in determining the position of an identifier (I) for accessing and starting a vehicle (V), relative to the vehicle (V), comprising: transmission (Em_TSvp), from a first device, either the vehicle (V) or the identifier (I) to a second device, different from the first, either the vehicle (V) or the identifier (I), at a transmission time t0, of an initial train (TSvp) of N sinusoidal signals, having identical amplitudes and respective frequencies fp, pϵ[1;N], for any p between 1 and N−1; reception (Rec_TSvp′) by the second device of an image train (TSvp′) corresponding to the initial train (TSvp, TSip) altered by the transmission (Em_TSvp); construction (Cons_Spv) of a frequency spectrum (Spv) for the image train (TSvp′); inverse Fourier transformation (TFI_Spv) of the spectrum (Spv), allowing a time signature (Sgv) to be obtained; first integration (Int1_Sgv) of the time signature (Sgv), between the transmission time t0 and a pre-determined intermediate time tint, producing a first result (Rlt1); second integration (Int2_Sg v) of the time signature (Sgv) between the intermediate time tint and a pre-determined end time tf, producing a second result (Rlt2); comparison (Comp_1/2) of a ratio (R) of the first result (Rlt1) to the second result (Rlt2) with a threshold value (S), so that it is possible to determine if the identifier (I) is positioned inside the vehicle (V).
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Citations
6 Claims
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1. A method for assisting in determining a position of an identifier for accessing and starting a vehicle, in relation to said vehicle, the method comprising:
transmission, from a first device from among the vehicle and the identifier, to a second device, separate from the first, from among the vehicle and the identifier, at a transmission time t0, of an initial train of N sinusoidal signals, with identical amplitudes and with respective frequencies fp, pϵ
[1;
N], such that, for all values of p between 1 and N−
1;reception, by the second device, of an image train corresponding to the initial train altered by the transmission, construction of a frequency spectrum of the image train, an inverse Fourier transform of the spectrum to obtain a temporal signature a first integration of the temporal signature, between the transmission time and a predetermined intermediate time tint, to obtain a first result a second integration of the temporal signature, between the intermediate time and a predetermined final time tf, to obtain a second result, and comparison of a ratio of the first result to the second result with a threshold value, to determine whether the identifier is positioned inside the vehicle. - View Dependent Claims (2, 3, 4, 5, 6)
Specification