JP-7856419-B2 - Location determination system

JP7856419B2JP 7856419 B2JP7856419 B2JP 7856419B2JP-7856419-B2

Inventors

山口晃平

Assignees

ミネベアミツミ株式会社

Dates

Publication Date: 20260511
Application Date: 20211214

Claims (6)

At least three first communication devices are provided inside the vehicle's interior, which is enclosed by the vehicle's metal body , and each device obtains the distance to a mobile terminal via wireless communication with the vehicle's surroundings or inside the vehicle's interior. A plurality of second communication devices are provided outside the passenger compartment of the vehicle and each acquires the distance to the mobile terminal, The system comprises a location determination unit that determines the location of the mobile terminal from the distances acquired by at least three first communication devices and the plurality of second communication devices, The aforementioned at least three first communication devices include three first communication devices that are positioned at different locations from one another when viewed along the vehicle height direction. At least two of the three first communication devices are positioned at different locations in the vehicle's longitudinal direction. Of the three first communication devices, at least two are positioned at different locations in the vehicle width direction. At least two of the aforementioned plurality of second communication devices are arranged at different positions from each other in the vehicle length direction or vehicle width direction. The at least three first communication devices are provided at a position higher than the lower edge of the vehicle's side window, and the plurality of second communication devices are provided at a position lower than the lower edge of the side window. The position determination system is configured such that the position determination unit determines the spatial position of the mobile terminal located outside the vehicle using the distance obtained by a combination of communication devices including at least one of the at least three first communication devices and at least one of the plurality of second communication devices .
The position determination system according to claim 1, wherein, when viewed along the vehicle height direction, the three straight lines connecting the three first communication devices form a triangle.
Two of the three first communication devices are provided on a pair of front pillars of the vehicle, The position determination system according to claim 1 or 2, wherein one of the at least three first communication devices is provided on the rear window or on a peripheral member located around the rear window.
A region determination unit determines, based on the position of the mobile terminal determined by the position determination unit, which of a plurality of regions set around the vehicle or inside the vehicle the mobile terminal is located in. The system includes a selection unit that selects a distance from the distances acquired by the at least three first communication devices and the plurality of second communication devices, according to the region in which the mobile terminal is located, as determined by the region determination unit. The position determination system according to any one of claims 1 to 3, wherein the position determination unit determines the provisional position of the mobile terminal from any distance among the distances acquired by the at least three first communication devices and the plurality of second communication devices, respectively, when no distance has been selected by the selection unit, and determines the position of the mobile terminal from the distance selected by the selection unit when a distance has been selected by the selection unit.
The position determination system according to claim 4, wherein the selection unit selects the distance such that it includes at least one of the distances acquired by the at least three first communication devices.
The position determination system according to claim 4 or 5, wherein the selection unit selects the distance acquired by the first communication device as having a higher priority than the distance acquired by the second communication device.

Description

This disclosure relates to a location determination system. Conventional location determination systems involve wireless communication between multiple communication devices installed in a vehicle and a mobile terminal carried by the user, and determining the position of the mobile terminal relative to the vehicle using radio wave propagation time or signal strength. For example, Patent Document 1 describes a location determination system that determines the position of three communication devices and a mobile terminal arranged side-by-side in the vehicle's width direction. Japanese Patent Publication No. 2021-096119 A block diagram of a position determination system according to an embodiment of the present disclosure.A top view of the vehicle according to the above embodiment.A side view of the vehicle according to the above embodiment.A diagram showing the region according to the above embodiment.A diagram showing the selection table according to the above embodiment.A flowchart of the position determination process according to the above embodiment. The embodiments of this disclosure will be described below with reference to the attached drawings. Referring to Figure 1, the location determination system 1 determines the location of the smartphone 3 either in the vicinity of the vehicle 2 (shown in Figure 2) (i.e., outside the vehicle compartment) or inside the vehicle compartment. The location determination system 1 is mounted on the vehicle 2. The location determination system 1 comprises three first communication devices 10A to 10C, four second communication devices 20A to 20D, and a control device 30. The smartphone 3 in this embodiment is an example of a mobile terminal according to this disclosure. The mobile terminal according to this disclosure is not limited to the smartphone 3 in this embodiment; for example, it may be a tablet terminal or a wearable terminal. In the following explanation, the longitudinal direction of vehicle 2 (i.e., the vehicle length direction) may be referred to as the X direction, the lateral direction of vehicle 2 (i.e., the vehicle width direction) as the Y direction, and the vertical direction of vehicle 2 (i.e., the vehicle height direction) as the Z direction. In the following explanation, when there is no need to distinguish between the three first communication devices 10A to 10C, one of them may simply be referred to as "first communication device 10." Similarly, when there is no need to distinguish between the four second communication devices 20A to 20D, one of them may simply be referred to as "second communication device 20." Furthermore, when there is no need to distinguish between the first communication device 10 and the second communication device 20, one of them may simply be referred to as "communication device." The communication device is a wireless communication device that communicates wirelessly with smartphone 3. The communication device uses UWB (Ultra Wide Band) communication with smartphone 3. The communication device obtains the distance between itself and the smartphone 3 by communicating wirelessly with the smartphone 3. Upon receiving a request signal from the smartphone 3, the communication device sends a response signal to the smartphone 3. Upon receiving the response signal from the communication device, the smartphone 3 calculates the time Δt1 from the time the request signal was sent until the response signal was received. The smartphone 3 then sends information about time Δt1 to the communication device. The communication device calculates the time Δt2 from the time Δt1 until the time the response signal was sent. The communication device calculates the signal propagation time between itself and the smartphone 3 from times Δt1 and Δt2. The communication device calculates and obtains the distance from itself to the smartphone 3 by multiplying the propagation time by the signal speed. As shown in Figures 2 and 3, the first communication device 10 is located inside the passenger compartment of the vehicle 2. In this embodiment, the first communication devices 10A and 10B are attached to a pair of front pillars RFP and LFP of the vehicle 2, respectively. The pair of front pillars RFP and LFP are located between the windshield WS, which is a non-metallic material such as glass located at the front of the passenger compartment, and the side window SW, which is a non-metallic material such as glass located at the side of the passenger compartment. In this embodiment, the first communication device 10C is attached to the rear window RW, which is a non-metallic material such as glass located at the rear of the passenger compartment. The first communication device 10C may also be attached to a peripheral member (not shown) made of resin located around the rear window RW. In other words, the first communication device 10C may be attached to a peripheral member arranged surrounding the rear window RW. As shown in Figure 2, the first communication