In-vehicle device, recording medium, and keyless entry system

Patent metadata

Field	Value
Publication number	US-10894527-B2
Application number	US-201916452844-A
Country	US
Kind code	B2
Filing date	Jun 26, 2019
Priority date	Jul 10, 2018
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

An in-vehicle device includes a plurality of transmitting antennas, an in-vehicle device transmitter configured to transmit measurement signals via the plurality of respective transmitting antennas, an in-vehicle device receiver configured to receive, from a portable device, a measurement result signal that includes measurement data of received signal strengths of the respective measurement signals that have been transmitted from the plurality of respective transmitting antennas; and an in-vehicle device controller configured to calculate first distances from the portable device to a plurality of preset areas, based on differences between the received signal strengths of the respective measurement signals included in the measurement result signal, and to identify an area to which the portable device belongs from the plurality of preset areas based on the first distances.

First claim

What is claimed is:

1. An in-vehicle device provided in a vehicle and comprising:
a plurality of transmitting antennas;
an in-vehicle device transmitter configured to transmit measurement signals via the plurality of respective transmitting antennas;
an in-vehicle device receiver configured to receive, from a portable device, a measurement result signal that includes measurement data of received signal strengths of the respective measurement signals that have been transmitted from the plurality of respective transmitting antennas; and
an in-vehicle device controller configured to calculate first distances from the portable device to a plurality of preset areas, based on differences between a reference received signal strength that is received from one transmitting antenna and each of the received signal strengths of the respective measurement signals that are received from a rest of the plurality of transmitting antennas included in the measurement result signal, and to identify an area to which the portable device belongs from the plurality of preset areas based on the first distances, said difference being calculated as dij=xi−xj,
wherein the xi is the reference received signal strength and xj is the each of the received signal strengths that are received from the rest of the plurality of transmitting antennas, and
wherein the reference received signal strength is received from the one transmitting antenna that is provided in a center of the vehicle.

2. The in-vehicle device according to claim 1 , wherein the first distances are Mahalanobis distances or Euclidean distances.

3. The in-vehicle device according to claim 1 , wherein the in-vehicle device controller calculates second distances from the portable device to the plurality of preset areas, based on the received signal strengths of the respective measurement signals included in the measurement result signal, and to identify an area to which the portable device belongs from the plurality of preset areas based on the first distances and the second distances.

4. The in-vehicle device according to claim 3 , wherein the second distances are Mahalanobis distances or Euclidean distances.

5. The in-vehicle device according to claim 1 , wherein the in-vehicle device transmitter includes one in-vehicle device transmitter connected to the plurality of transmitting antennas.

6. The in-vehicle device according to claim 1 , wherein the in-vehicle device transmitter includes a plurality of in-vehicle device transmitters each connected to a corresponding transmitting antenna of the plurality of transmitting antennas.

7. The in-vehicle device according to claim 1 , wherein the number of the plurality of transmitting antennas is 5 and the number of the rest of the plurality of transmitting antennas is 4.

8. A non-transitory recording medium storing a program for causing a computer to execute a process comprising:
transmitting measurement signals from a plurality of respective transmitting antennas;
receiving, from a portable device, a measurement result signal that includes measurement data of received signal strengths of the respective measurement signals that have been transmitted from the plurality of respective transmitting antennas; and
calculating first distances from the portable device to a plurality of preset areas, based on differences between a reference received signal strength that is received from one transmitting antenna and each of the received signal strengths of the respective measurement signals that are received from a rest of the plurality of transmitting antennas included in the measurement result signal, and identifying an area to which the portable device belongs from the plurality of preset areas based on the first distances, said difference being calculated as dij=xi−xj,
wherein the xi is the reference received signal strength and xj is the each of the received signal strengths that are received from the rest of the plurality of transmitting antennas, and
wherein the reference received signal strength is received from the one transmitting antenna that is provided in a center of the vehicle.

9. A keyless entry system including a portable device and an in-vehicle device, the keyless entry system comprising:
a received signal strength measuring unit configured to measure received signal strengths of a plurality of respective measurement signals that have been transmitted from a plurality of transmitting antennas;
a distance calculating unit configured to calculate first distances from the portable device to a plurality of areas, based on differences between a reference received signal strength that is received from one transmitting antenna and each of the received signal strengths of the plurality of respective measurement signals that are received from a rest of the plurality of transmitting antennas; and
an area identifying unit configured to identify an area to which the portable device belongs from the plurality of areas based on the first distances, said difference being calculated as dij=xi−xj,
wherein the xi is the reference received signal strength and xj is the each of the received signal strengths that are received from the rest of the plurality of transmitting antennas, and
wherein the reference received signal strength is received from the one transmitting antenna that is provided in a center of the vehicle.

Assignees

• Alps Alpine Co Ltd

Inventors

• Suzuki Yasuhiro
• Hayasaka Satoshi
• Nakajima Satoshi
• Fang Chengchun

Classifications

• H04B17/318

  Received signal strength · CPC title

• G01S5/02

  using radio waves (using satellite radio beacon systems for determining position G01S19/00) · CPC title

• H04W4/48

  for in-vehicle communication · CPC title

• B60R25/245 Primary

  where the antenna reception area plays a role · CPC title

• G06F17/11

  for solving equations {, e.g. nonlinear equations, general mathematical optimization problems (optimization specially adapted for a specific administrative, business or logistic context G06Q10/04)} · CPC title