Control device, control method, and program

Abstract

To provide a mechanism that can further improve the accuracy of estimating positional relationships between devices.SOLUTION: A control device includes a control unit that repeatedly executes, for each of a plurality of wireless communication units that perform wireless communication with another communication device, a process of calculating coordinates indicating the position of the other communication device and a reliability parameter indicating the reliability of the coordinates based on wireless signals transmitted and received by each of the plurality of wireless communication units, and estimates the presence area of the other communication device by preferentially referring to the coordinates obtained by a wireless communication unit that has obtained a greater number of highly reliable coordinates among a plurality of wireless communication units that have obtained highly reliable coordinates.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device, a control method, and a program. [Background technology]

[0002] In recent years, a technology has been developed that estimates the positional relationship between devices based on the results of transmitting and receiving wireless signals between the devices. For example, Patent Document 1 below discloses a technology that estimates the angle of arrival of a signal using UWB (Ultra-Wide Band). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 176776 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 above had a problem in that it did not address the possibility that the accuracy of estimating the angle of arrival may decrease in environments where there are obstructions between the transmitter and receiver.

[0005] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a mechanism that can further improve the estimation accuracy of the positional relationship between devices. [Means for solving the problem]

[0006] In order to solve the above problem, according to one aspect of the present invention, a control device is provided that includes a control unit that repeatedly executes a process of calculating coordinates indicating the position of the other communication device and a reliability parameter indicating the reliability of the coordinates based on wireless signals transmitted and received by each of a plurality of wireless communication units that perform wireless communication with the other communication device, for each of the plurality of wireless communication units, and estimates the presence area of ​​the other communication device by preferentially referring to the coordinates obtained by the wireless communication units that obtained a greater number of highly reliable coordinates among the plurality of wireless communication units from which highly reliable coordinates have been obtained.

[0007] In addition, in order to solve the above problem, according to another aspect of the present invention, there is provided a control method executed by a computer, which includes repeatedly executing, for each of a plurality of wireless communication units, a process of calculating coordinates indicating the position of the other communication device and a reliability parameter indicating the reliability of the coordinates based on wireless signals transmitted and received by each of the plurality of wireless communication units that perform wireless communication with the other communication device, and estimating the presence area of ​​the other communication device by preferentially referring to the coordinates obtained by the wireless communication units that obtained a greater number of highly reliable coordinates in the plurality of wireless communication units from which highly reliable coordinates have been obtained.

[0008] In addition, in order to solve the above problem, according to another aspect of the present invention, a program is provided to cause a computer to function as a control unit that repeatedly executes a process of calculating, for each of a plurality of wireless communication units that perform wireless communication with other communication devices, coordinates indicating the position of the other communication device and a reliability parameter indicating the reliability of the coordinates based on wireless signals transmitted and received by each of the plurality of wireless communication units that perform wireless communication with the other communication device, and estimates the presence area of ​​the other communication device by preferentially referring to the coordinates obtained by the wireless communication units that obtained a greater number of highly reliable coordinates among the plurality of wireless communication units that obtained highly reliable coordinates. Effect of the Invention

[0009] As described above, according to the present invention, a mechanism is provided that can further improve the estimation accuracy of the positional relationship between devices. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an example of a configuration of a system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining an example of an arrangement of antennas according to the embodiment. [Diagram 3] FIG. 2 is a diagram illustrating an example of a processing block of a wireless communication unit according to the embodiment. [Figure 4] 1 is a graph showing an example of a CIR according to the present embodiment. [Diagram 5] FIG. 11 is a sequence diagram for explaining an example of the flow of a process relating to estimation of a position parameter executed in the system according to the present embodiment. [Figure 6] 6 is a diagram for explaining an example of a process for estimating a presence area of ​​a portable device according to the embodiment; FIG. [Figure 7] 5 is a flowchart showing an example of a flow of processing executed by the control device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and duplicated explanations will be omitted.

[0012] In addition, in this specification and drawings, elements having substantially the same functional configuration may be distinguished by adding different alphabets after the same reference numeral. For example, multiple elements having substantially the same functional configuration may be distinguished as in-vehicle devices 200A and 200B as necessary. However, when there is no need to particularly distinguish between multiple elements having substantially the same functional configuration, only the same reference numeral may be added. For example, when there is no need to particularly distinguish between in-vehicle devices 200A and 200B, they are simply referred to as in-vehicle device 200.

[0013] <1. Configuration example> Fig. 1 is a block diagram showing an example of a configuration of a system 1 according to an embodiment of the present invention. As shown in Fig. 1, the system 1 according to the present embodiment includes a portable device 100, a plurality of vehicle-mounted devices 200 (200A and 200B), a control device 300, and a controlled device 400.

[0014] The vehicle-mounted device 200, the control device 300, and the controlled device 400 according to this embodiment are mounted on a vehicle 20. The vehicle 20 is an example of a moving body, and is, for example, a vehicle in which a user is permitted to ride (for example, a vehicle owned by the user, or a vehicle temporarily loaned to the user). Note that the moving body according to this embodiment includes not only the vehicle 20, but also an airplane, a ship, and the like.

[0015] (Portable device 100) The portable device 100 is an example of another communication device, and is a device carried by a user who uses the vehicle 20. The portable device 100 may be an electronic key, a smartphone, a tablet terminal, a wearable terminal, or the like. As shown in FIG. 1, the portable device 100 includes a control unit 110 and a wireless communication unit 120.

[0016] The control unit 110 controls the overall operation of the portable device 100. The control unit 110 controls the wireless communication unit 120 to transmit and receive wireless signals to and from the vehicle-mounted device 200. The control unit 110 is configured with an electronic circuit such as a CPU (Central Processing Unit) or a microprocessor.

[0017] The wireless communication unit 120 performs wireless communication with the vehicle-mounted device 200. Such wireless communication may be performed, for example, using a signal using UWB (hereinafter also referred to as a UWB signal). If an impulse method is used in wireless communication using a UWB signal, the propagation delay time of the radio wave can be measured with high accuracy by using a radio wave with a very short pulse width of less than nanoseconds, and distance measurement based on the propagation delay time can be performed with high accuracy. The wireless communication unit 120 is configured, for example, as a communication interface capable of communication using a UWB signal.

[0018] Moreover, the wireless communication unit 120 has at least one antenna 121. The wireless communication unit 120 transmits and receives wireless signals via the at least one antenna 121.

[0019] (Onboard device 200) The vehicle-mounted device 200 is an example of a communication device, and is a device mounted on the vehicle 20. The number of vehicle-mounted devices 200 mounted on the vehicle 20 is not limited to two, and may be three or more. As shown in FIG. 1, the vehicle-mounted device 200 includes a control unit 210 and a wireless communication unit 220.

[0020] The control unit 210 controls the overall operation of the vehicle-mounted device 200. The control unit 210 controls the wireless communication unit 220 to transmit and receive wireless signals to and from the portable device 100. The control unit 210 is configured by an electronic circuit such as an ECU (Electronic Processing Unit) or a microprocessor.

[0021] The wireless communication unit 220 performs wireless communication with the portable device 100. Such wireless communication may be performed using, for example, UWB signals. The wireless communication unit 220 is configured as, for example, a communication interface capable of communication using UWB signals.

[0022] Moreover, the wireless communication unit 220 has at least three or more antennas 221. The wireless communication unit 220 transmits and receives wireless signals via the three or more antennas 221.

[0023] In the following, it is assumed that the wireless communication unit 220 has four antennas 221. An example of the arrangement of the four antennas 221 will be described with reference to FIG.

[0024] FIG. 2 is a diagram for explaining an example of the arrangement of the antennas 221 according to the present embodiment. As shown in FIG. 2, the four antennas 221 (221A to 221D) may be arranged at positions forming a square on the wireless communication unit 220. The antennas 221A and 221C, and the antennas 221B and 221D are arranged in parallel to the X-axis. The X-axis may be, for example, an axis extending in the front-rear direction of the vehicle 20. On the other hand, the antennas 221A and 221B, and the antennas 221C and 221D are arranged in parallel to the Y-axis. The Y-axis may be, for example, an axis extending in the left-right direction of the vehicle 20. An axis perpendicular to the X-axis and the Y-axis is defined as the Z-axis. The Z-axis may be an axis extending in the up-down direction of the vehicle.

[0025] The arrangement and scale of the wireless communication unit 220 and the antenna 221 are not limited to the example shown in Fig. 2. For example, the interval between adjacent antennas 221 in the X-axis direction or the Y-axis direction may be about 1 / 2 the wavelength of a wireless signal. The arrangement shape of the four antennas may be a square, parallelogram, trapezoid, rectangle, or any other shape. However, it is desirable that the multiple antennas 221 are arranged on a plane, not on the same straight line.

[0026] (Control device 300) The control device 300 has a function of controlling other devices mounted on the vehicle 20. The control device 300 communicates with and controls the in-vehicle device 200 and the controlled device 400 via an in-vehicle network such as a Controller Area Network (CAN) or a Local Interconnect Network (LIN). As shown in FIG. 1, the control device 300 includes a control unit 310.

[0027] The control unit 310 controls the overall operation of the control device 300. As one example, the control unit 310 controls the in-vehicle device 200 to perform wireless communication with the portable device 100. As another example, the control unit 310 estimates the position of the portable device 100 based on a result of wireless communication by the portable device 100. As another example, the control unit 310 controls the operation of the controlled device 400 based on the estimated position of the portable device 100. The control unit 310 is configured by an electronic circuit such as an ECU or a microprocessor.

[0028] (Controlled device 400) The controlled device 400 is a device that operates according to the control of the control device 300. The controlled device 400 may be a door lock of the vehicle 20 or an engine of the vehicle 20. For example, the control device 300 may lock or unlock the door lock of the vehicle 20, or permit or restrict the starting of the engine of the vehicle 20.

[0029] The configuration example of the system 1 according to the present embodiment has been described above.

[0030] <2. Technical features> <2.1. Estimation of location parameters> (CIR) Each of the portable device 100 (more specifically, the control unit 110) and the vehicle-mounted device 200 (more specifically, the control unit 210) can calculate a Channel Impulse Response (CIR).

[0031] The CIR is a response when an impulse is input to the system, and indicates the characteristics of the wireless communication path between the portable device 100 and the vehicle-mounted device 200.

[0032] The CIR can be calculated by taking a sliding correlation between a wireless signal (hereinafter also referred to as a transmission signal) transmitted by a transmitting side and a wireless signal (hereinafter also referred to as a reception signal) received by a receiving side. More specifically, the receiving side calculates a value obtained by taking a correlation between the received signal and a transmission signal delayed by a certain delay time as a characteristic at the delay time (hereinafter also referred to as a CIR value). Then, the receiving side calculates the CIR by calculating the CIR value for each delay time. That is, the CIR is a time series transition of the CIR value. Here, the CIR value is a complex number having an I component and a Q component. The sum of squares of the I component and the Q component of the CIR value may be referred to as the power value of the CIR. In addition, in a ranging technique using UWB, the CIR value is also referred to as a delay profile. In addition, in a ranging technique using UWB, the sum of squares of the I component and the Q component of the CIR value is also referred to as a power delay profile.

[0033] Hereinafter, the CIR calculation process in the case where the transmitting side is the portable device 100 and the receiving side is the vehicle-mounted device 200 will be described in detail with reference to FIGS.

[0034] 3 is a diagram showing an example of a processing block of the wireless communication unit 220 according to the present embodiment. As shown in FIG. 3, the wireless communication unit 220 includes an antenna 221, an oscillator 222, a multiplier 223, a 90-degree phase shifter 224, a multiplier 225, an LPF (Low Pass Filter) 226, an LPF 227, a correlator 228, and an accumulator 229.

[0035] The oscillator 222 generates a signal having the same frequency as the frequency of the carrier wave that carries the transmission signal, and outputs the generated signal to the multiplier 223 and the 90-degree phase shifter 224 .

[0036] Multiplier 223 multiplies the signal received by antenna 221 by the signal output from oscillator 222, and outputs the multiplication result to LPF 226. LPF 226 outputs, of the input signals, signals having a frequency equal to or lower than the frequency of the carrier wave carrying the transmission signal, to correlator 228. The signal input to correlator 228 is the I component (i.e., the real part) of the components corresponding to the envelope of the received signal.

[0037] The 90-degree phase shifter 224 delays the phase of the input signal by 90 degrees and outputs the delayed signal to the multiplier 225. The multiplier 225 multiplies the signal received by the antenna 221 by the signal output from the 90-degree phase shifter 224, and outputs the multiplication result to the LPF 227. The LPF 227 outputs, of the input signals, signals having a frequency equal to or lower than the frequency of the carrier wave carrying the transmission signal to the correlator 228. The signal input to the correlator 228 is the Q component (i.e., the imaginary part) of the components corresponding to the envelope of the received signal.

[0038] The correlator 228 calculates the CIR by taking a sliding correlation between the received signal consisting of the I component and the Q component output from the LPF 226 and the LPF 227 and the reference signal. Note that the reference signal here is the same signal as the transmitted signal before being multiplied by the carrier wave.

[0039] The accumulator 229 accumulates the CIR output from the correlator 228 and outputs the accumulated result.

[0040] Here, the transmitting side may transmit a signal including a preamble including one or more preamble symbols as a transmission signal. The preamble is a sequence known between the transmitting side and the receiving side. The preamble is typically placed at the beginning of the transmission signal. The preamble symbol is a pulse sequence including one or more pulses. The pulse sequence is a set of multiple pulses separated in the time direction. The preamble symbol is the target of accumulation by the accumulator 229. That is, the correlator 228 calculates the CIR for each preamble symbol by taking a sliding correlation between each of the parts corresponding to the multiple preamble symbols included in the received signal and the preamble symbol included in the transmission signal. Then, the accumulator 229 accumulates the CIR for each preamble symbol for one or more preamble symbols included in the preamble, and outputs the CIR after accumulation. In the following, unless otherwise specified, the CIR refers to the CIR after accumulation.

[0041] The wireless communication unit 220 performs the above-mentioned processing on each of the signals received by the multiple antennas 221.

[0042] (Detection of first arriving wave) FIG. 4 is a graph showing an example of the CIR output from the integrator 229. The horizontal axis of the graph is the delay time, and the vertical axis is the delay profile. In the CIR, a piece of information that constitutes information that changes along a time series, such as the CIR value at a certain delay time, is also called a sampling point. In the CIR, typically, a set of sampling points between zero crossing points corresponds to one pulse. A zero crossing point is a sampling point where the value becomes zero. However, this is not the case in a noisy environment. For example, a set of sampling points between the intersection points of a reference level other than zero and the transition of the CIR value may be considered to correspond to one pulse. The CIR shown in FIG. 4 includes a set of sampling points 21 corresponding to a certain pulse and a set of sampling points 22 corresponding to another pulse.

[0043] Set 21 corresponds to, for example, fast path signals (hereinafter also referred to as first arriving waves). A fast path refers to the shortest path between a transmitter and a receiver, and refers to the straight line distance between a transmitter and a receiver in an environment without obstructions. A first arriving wave is a signal that has reached the receiver via a fast path. Set 22 corresponds to, for example, signals that have reached the receiver via a path other than the fast path.

[0044] The receiving side detects, as the first arriving wave, a signal that satisfies a predetermined criterion first among the received wireless signals. One example of the predetermined detection criterion is that the CIR value (e.g., amplitude or power) exceeds a predetermined threshold first. That is, the receiving side may detect, as the first arriving wave, a signal that corresponds to a portion of the CIR where the CIR value exceeds the predetermined threshold first.

[0045] The first arriving wave can be either a direct wave, a delayed wave, or a composite wave. A direct wave is a signal that is received by the receiving side directly (i.e., without being reflected, etc.) via the shortest path between the transmitting and receiving side. A delayed wave is a signal that is received by the receiving side indirectly via a path that is not the shortest between the transmitting and receiving side, i.e., after being reflected, etc. A delayed wave is received by the receiving side with a delay relative to the direct wave. A composite wave is a signal that is received by the receiving side in a state in which multiple signals that have passed through multiple different paths are combined.

[0046] It should be noted here that the signal detected as the first arriving wave is not necessarily a direct wave. For example, when a direct wave is received in a state where it cancels out a delayed wave, the CIR value of the direct wave may fall below a predetermined threshold, and the direct wave may not be detected as the first arriving wave. In that case, a delayed wave or a composite wave that arrives later than the direct wave may be detected as the first arriving wave.

[0047] Typically, in a Line of Sight (LOS) state, the receiver is more likely to successfully detect the direct wave as the first arriving wave. The LOS state refers to a state in which there is no obstruction between the transmitter and receiver, and the receiver is able to see each other.

[0048] On the other hand, in a non-line-of-sight (NLOS) state, the receiver may fail to detect the direct wave as the first arriving wave. An NLOS state refers to a state in which the transmitter and receiver are not visible to each other, for example, due to the presence of an obstruction between them.

[0049] In the following, unless otherwise specified, the signal refers to the first arriving wave.

[0050] (Estimation of location parameters) The control device 300 (more specifically, the control unit 310) according to this embodiment estimates a position parameter indicating the position where the portable device 100 is located, based on the result of the wireless communication (particularly, the first incoming wave) performed between the portable device 100 and the vehicle-mounted device 200. The position parameter is information indicating the relative position of the portable device 100 with the vehicle-mounted device 200 as a reference.

[0051] An example of the location parameter is the distance between the portable device 100 and the vehicle-mounted device 200. The distance between the portable device 100 and the vehicle-mounted device 200 can be estimated based on, for example, a propagation delay time (i.e., ToF (Time of Flight)). The estimated distance is also referred to as a ranging value.

[0052] An example of the position parameter is the arrival angle of a wireless signal received by the vehicle-mounted device 200 from the portable device 100. The arrival angle of the wireless signal can be estimated based on the phase difference of the received wireless signal in an antenna array constituted by two antennas 221, for example.

[0053] An example of the location parameter is the coordinates of the portable device 100. The coordinates of the portable device 100 can be estimated, for example, by combining an estimation result of the distance between the portable device 100 and the vehicle-mounted device 200 and an estimation result of the angle of arrival of the wireless signal received by the vehicle-mounted device 200 from the portable device 100.

[0054] Hereinafter, an example of a process flow relating to estimation of the position parameters will be described with reference to FIG.

[0055] FIG. 5 is a sequence diagram for explaining an example of the flow of processing related to estimation of position parameters executed in the system 1 according to this embodiment.

[0056] First, the antenna 121 of the portable device 100 transmits a Poll (Polling) signal (step S101).

[0057] Next, when the antenna 221A of the vehicle-mounted device 200 receives the Poll signal, the antenna 221A transmits a Resp (Response) signal as a response to the received Poll signal (step S103).

[0058] Then, when the antenna 121 of the portable device 100 receives the Resp signal, it transmits a Final signal in response to the received Resp signal (steps S105a to S105d). The Final signal is received by the antennas 221A to 221D of the vehicle-mounted device 200.

[0059] Here, the time length from when the portable device 100 transmits the Poll signal to when it receives the Resp signal is defined as time length T1, the time length from when it receives the Resp signal to when it transmits the Final signal is defined as time length T2, the time length from when the vehicle-mounted device 200 receives the Poll signal to when it transmits the Resp signal is defined as time length T3, and the time length from when it transmits the Resp signal to when it receives the Final signal is defined as time length T4.

[0060] The control device 300 calculates the propagation delay time τ of the signal using the time lengths T1 to T4. For example, the control device 300 calculates the propagation delay time τ by the following formula. The control device 300 may then estimate the distance between the portable device 100 and the vehicle-mounted device 200 by multiplying the calculated propagation delay time τ of the signal by a known speed of the signal.

[0061]

number

[0062] Furthermore, the control device 300 estimates the arrival angle of the signal received by the vehicle-mounted device 200 from the portable device 100 based on the phase of the signal received by the antennas 221A to 221D. For example, the control device 300 estimates the arrival angle of the Final signal by the following equation.

[0063]

number

[0064]

number

[0065] Note that Pd is the phase difference between the signals received by adjacent antennas, as indicated by the associated index. For example, Pd AC is the phase difference between the signals received by antenna 221A and antenna 221C.

[0066] λ is the wavelength of the radio wave. d is the distance between the antennas 221. α is the angle of arrival of the signal relative to the X-axis. β is the angle of arrival of the signal relative to the Y-axis.

[0067] Furthermore, the control device 300 may estimate the coordinates of the portable device 100 based on the estimated distance and angle of arrival. For example, the control device 300 estimates the coordinate x on the X axis, the coordinate y on the Y axis, and the coordinate z on the Z axis of the portable device 100 by the following equations.

[0068]

number

[0069] Here, R is an estimate of the distance between the portable device 100 and the vehicle-mounted device 200 (that is, a measured distance value).

[0070] 2.2. Calculation of reliability parameters The control device 300 according to this embodiment calculates a reliability parameter indicating the reliability of the signal (i.e., the first arriving wave) received by the vehicle-mounted device 200. The reliability of a signal is an index indicating the suitability of the signal for use in estimating a position parameter. The reliability of a signal may be regarded as an index indicating the likelihood that the signal is a direct wave, that is, an index indicating the likelihood that the signal was detected in an LOS state. The higher the reliability of a signal, the higher the estimation accuracy of the position parameter calculated based on the signal. On the other hand, the lower the reliability of a signal, the lower the estimation accuracy of the position parameter calculated based on the signal.

[0071] There are various examples of the reliability parameter. As one example, the reliability parameter may be the signal noise ratio (SNR) of the signal. As another example, the reliability parameter may be the received signal strength of the signal (e.g., a Received Signal Strength Indicator (RSSI)). As another example, the reliability parameter may be the variation in the reception time of the Final signal (i.e., the detection time of the first arriving wave) between the antennas 221.

[0072] <2.3. Estimation of presence area based on reliability parameters> The control device 300 causes each of the multiple vehicle-mounted devices 200 to perform wireless communication multiple times to obtain multiple estimation results of the coordinates of the portable device 100 (hereinafter also referred to as first coordinates). Next, the control device 300 estimates final values ​​of the coordinates of the portable device 100 (hereinafter also referred to as second coordinates) based on the multiple first coordinates. Then, the control device 300 estimates an area corresponding to the second coordinates as an area in which the portable device 100 exists (hereinafter also referred to as a presence area). Examples of areas in which the portable device 100 may exist include spaces based on the vehicle 20, such as an area outside the vehicle cabin, an area in front of the vehicle, an area behind the vehicle, an area around the driver's seat, or an area around the passenger seat.

[0073] The process of estimating the area in which the portable device 100 is present will be described in detail below.

[0074] First, the control device 300 repeatedly executes a process of calculating a first coordinate indicating the position of the portable device 100 and a reliability parameter indicating the reliability of the first coordinate for each of the multiple vehicle-mounted devices 200 that wirelessly communicate with the portable device 100 based on a wireless signal transmitted and received by each of the multiple vehicle-mounted devices 200. The reliability parameter of the first coordinate is synonymous with the reliability parameter calculated for the signal used to estimate the first coordinate. High reliability of the signal used to estimate the first coordinate indicates high reliability of the estimated first coordinate, that is, high estimation accuracy of the estimated first coordinate. Through this process, the control device 300 acquires multiple combinations of the first coordinate and the reliability parameter of the first coordinate.

[0075] Then, the control device 300 estimates the presence area of ​​the portable device 100 based on multiple combinations of the acquired first coordinates and the reliability parameter. In detail, the control device 300 estimates the second coordinates based on the first coordinates having high reliability indicated by the reliability parameter (hereinafter also referred to as the highly reliable first coordinates), and estimates the area corresponding to the second coordinates as the presence area of ​​the portable device 100. The highly reliable first coordinates here may be the first coordinates having reliability indicated by the reliability parameter that is equal to or higher than a certain threshold.

[0076] The control device 300 estimates the location area of ​​the portable device 100 by preferentially referring to the first coordinates obtained by the vehicle-mounted devices 200 from which a greater number of highly reliable first coordinates have been obtained, among the vehicle-mounted devices 200 from which highly reliable first coordinates have been obtained. With this configuration, it is possible to improve the accuracy of estimating the location area of ​​the portable device 100.

[0077] In particular, when the number of highly reliable first coordinates obtained is not competitive among the multiple vehicle-mounted devices 200, the control device 300 estimates the presence area of ​​the portable device 100 by preferentially referring to the first coordinates obtained by the vehicle-mounted devices 200 that have obtained a greater number of highly reliable first coordinates. Depending on the positional relationship between the multiple vehicle-mounted devices 200 and the portable device 100, the vehicle-mounted devices 200 that are in the LOS state and have high estimation accuracy of the first coordinates and the vehicle-mounted devices 200 that are in the NLOS state and have low estimation accuracy of the first coordinates may be mixed. Therefore, if the first coordinates obtained by all the vehicle-mounted devices 200 are treated equally to estimate the second coordinates, the estimation accuracy of the second coordinates may decrease, and as a result, the estimation accuracy of the presence area of ​​the portable device 100 may decrease. In this regard, according to this configuration, it is possible to preferentially refer to the data obtained by the vehicle-mounted devices 200 that are likely to be in the LOS state, and therefore it is possible to improve the estimation accuracy of the presence area of ​​the portable device 100.

[0078] When the number of highly reliable first coordinates obtained in the multiple vehicle-mounted devices 200 is comparable, the control device 300 may estimate the presence area of ​​the portable device 100 by equally referring to the first coordinates obtained by each of the multiple vehicle-mounted devices 200. Even in this case, since it is possible to refer to data obtained by the vehicle-mounted device 200 that is likely to be in an LOS state, it is possible to improve the estimation accuracy of the presence area of ​​the portable device 100.

[0079] An example of a process for estimating the presence area of ​​the portable device 100 will be described below with reference to Fig. 6. Fig. 6 is a diagram for explaining an example of a process for estimating the presence area of ​​the portable device 100 according to this embodiment. As shown in Fig. 6, it is assumed that the vehicle-mounted device 200A is disposed in the front of the cabin of the vehicle 20, and the vehicle-mounted device 200B is disposed in the rear of the cabin of the vehicle 20.

[0080] As shown in the following Table 1, the control device 300 acquires a first coordinates acquired by the vehicle-mounted device 200A and b first coordinates acquired by the vehicle-mounted device 200B. The control device 300 calculates reliability parameters of these first coordinates.

[0081] [Table 1]

[0082] Next, as shown in Table 2 below, the control device 300 extracts A first coordinates having high reliability indicated by the reliability parameter from among the a first coordinates obtained by the vehicle-mounted device 200A. Also, the control device 300 extracts B first coordinates having high reliability indicated by the reliability parameter from among the b first coordinates obtained by the vehicle-mounted device 200B.

[0083] [Table 2]

[0084] Then, the control device 300 estimates the presence area of ​​the portable device 100 based on the median value of the extracted A+B highly reliable first coordinates. In detail, as shown in Fig. 6, the control device 300 estimates the median value (Xm, Ym) of the A+B highly reliable first coordinates shown in Table 2 as the second coordinates. In this case, the control device 300 estimates the driver's seat surrounding area 30 corresponding to the estimated second coordinates (Xm, Ym) as the presence area of ​​the portable device 100.

[0085] When A and B are not the same, that is, when the number of highly reliable first coordinates obtained is not equal between the vehicle-mounted device 200A and the vehicle-mounted device 200B, the median is taken, so that the first coordinates obtained by the vehicle-mounted device 200 that has obtained a larger number of highly reliable first coordinates are preferentially referred to. The vehicle-mounted device 200 that has obtained a larger number of highly reliable first coordinates refers to the vehicle-mounted device 200 that is likely to be in an LOS state. In other words, according to this configuration, it is possible to preferentially refer to the data obtained by the vehicle-mounted device 200 that is likely to be in an LOS state, thereby improving the estimation accuracy of the presence area of ​​the portable device 100.

[0086] The median of multiple first coordinates is obtained by calculating the median for each of the X and Y coordinates. If A+B is an even number, the median may be the arithmetic mean of the two middle first coordinates.

[0087] An example of the flow of the above-described processing will now be described with reference to FIG.

[0088] FIG. 7 is a flowchart showing an example of the flow of processing executed by the control device 300 according to this embodiment.

[0089] 7, first, the control device 300 executes wireless communication multiple times for each vehicle-mounted device 200 (step S202). As a result, the control device 300 acquires multiple first coordinates.

[0090] Next, the control device 300 extracts highly reliable data (step S204). For example, the control device 300 calculates a reliability parameter for each of the multiple first coordinates acquired in step S202, and extracts the first coordinates whose reliability indicated by the reliability parameter is equal to or greater than a certain threshold.

[0091] Next, the control device 300 estimates the presence area of ​​the portable device 100 based on the extracted highly reliable data (step S206). For example, the control device 300 estimates the median value of the extracted multiple highly reliable first coordinates as the second coordinates, and estimates the area corresponding to the estimated second coordinates as the presence area of ​​the portable device 100.

[0092] Then, the control device 300 controls the operation of the controlled device 400 based on the estimated area where the portable device 100 is located (step S208). For example, the control device 300 unlocks the door when it estimates that the portable device 100 is located in the driver's seat area, and allows the engine to start when it estimates that the portable device 100 is located inside the vehicle.

[0093] <3. Modifications> <3.1. Modification of the method for calculating the second coordinate> In the above embodiment, the median value of the extracted multiple highly reliable first coordinates is estimated as the second coordinate, but the present invention is not limited to this example. Other examples will be described below.

[0094] (First example) The control device 300 may estimate, as the second coordinate, one first coordinate with the highest reliability among two or more highly reliable first coordinates near the median of the extracted multiple highly reliable first coordinates, and estimate the presence area of ​​the portable device 100 based on the estimated second coordinate. Here, the two or more highly reliable first coordinates near the median may be, for example, the two or three first coordinates in the middle of the ranking. With this configuration, the presence area of ​​the portable device 100 can be estimated based on the signal most likely to be detected in the LOS state, so that it is possible to improve the estimation accuracy of the presence area of ​​the portable device 100.

[0095] (Second example) The control device 300 may estimate two or more areas where the portable device 100 is present, based on two or more highly reliable first coordinates near the median value among the extracted multiple highly reliable first coordinates. For example, it is assumed that (Xm1, Ym1) and (Xm2, Ym2) are obtained as two or more highly reliable first coordinates near the median value among the extracted multiple highly reliable first coordinates. When the area corresponding to (Xm1, Ym1) is the driver's seat surrounding area and the area corresponding to (Xm2, Ym2) is the passenger seat surrounding area, the control device 300 may estimate the driver's seat surrounding area and the passenger seat surrounding area as the areas where the portable device 100 is present.

[0096] Although the estimation result does not narrow down the area where the portable device 100 is present to one, it may be a sufficient estimation result depending on the application. One example of such an application is a case where a door lock is unlocked when the area where the portable device 100 is present is the area around the driver's seat or the area around the passenger seat.

[0097] (Third example) The control device 300 may estimate the area where the portable device 100 is located by taking a majority vote from a plurality of areas corresponding to each of the extracted plurality of highly reliable first coordinates. For example, it is assumed that a combination of highly reliable first coordinates and areas corresponding to the highly reliable first coordinates shown in the following Table 3 is obtained. In this case, since the number of D areas (areas around the driver's seat) is greater than the number of P areas (areas around the passenger's seat), the control device 300 estimates that the area where the portable device 100 is located is the D area.

[0098] [Table 3]

[0099] Even with this configuration, when the number of highly reliable first coordinates obtained by the vehicle-mounted device 200A and the vehicle-mounted device 200B is not equal, the data obtained by the vehicle-mounted device 200 that is more likely to be in an LOS state can be preferentially referred to. As a result, it is possible to improve the estimation accuracy of the presence area of ​​the portable device 100.

[0100] (Example 4) The control device 300 may estimate the presence area of ​​the portable device 100 based on the first coordinates obtained by the vehicle-mounted device 200 from which a certain threshold or more of highly reliable first coordinates have been obtained. In other words, the control device 300 may discard the first coordinates obtained by the vehicle-mounted device 200 from which the number of highly reliable first coordinates obtained is less than a certain threshold. With this configuration, it is possible to refer to only the data obtained by the vehicle-mounted device 200 that is likely to be in an LOS state, thereby improving the estimation accuracy of the presence area of ​​the portable device 100.

[0101] <3.2. Modification of the method for extracting the first coordinate with high reliability> In the above embodiment, an example is described in which the first coordinates whose reliability indicated by the reliability parameter is equal to or greater than a certain threshold are extracted as the highly reliable first coordinates, but the present invention is not limited to such an example. Other examples are described below.

[0102] As an example, the control device 300 may extract the first coordinates acquired in a recent predetermined period or a predetermined number of first coordinates with the most recent acquisition time as the highly reliable first coordinates. Considering that the positional relationship between the portable device 100 and the vehicle-mounted device 200 may change from moment to moment, this configuration makes it possible to improve the estimation accuracy of the area where the portable device 100 is present. The recentness of the acquisition time may be regarded as a reliability parameter.

[0103] As another example, the control device 300 may extract, from among the first coordinates acquired within a specified period of time immediately preceding the present, those first coordinates whose reliability indicated by the reliability parameter is equal to or greater than a certain threshold value as highly reliable first coordinates.

[0104] As another example, the control device 300 may extract, from among the first coordinates acquired during the most recent specified period, the first coordinates whose reliability indicated by the reliability parameter is equal to or greater than a certain threshold and which are among the first coordinates with the highest reliability indicated by the reliability parameter, as highly reliable first coordinates.

[0105] As another example, the control device 300 may extract, from among the first coordinates acquired within a specified period of time immediately preceding the present, a predetermined number of first coordinates whose reliability indicated by the reliability parameter is equal to or exceeds a certain threshold and whose acquisition time is recent, as highly reliable first coordinates.

[0106] In addition, extracting a predetermined number of first coordinates may refer to extracting a predetermined number of first coordinates from each of the vehicle-mounted device 200A and the vehicle-mounted device 200B. Alternatively, extracting a predetermined number of first coordinates may refer to extracting a total of a predetermined number of first coordinates from the vehicle-mounted device 200A and the vehicle-mounted device 200B.

[0107] <3.3. Modification of reliability parameters> The control device 300 may calculate a reliability parameter based on the degree of agreement between the presence area of ​​the portable device 100 estimated based on the first coordinates and the presence area of ​​the portable device 100 estimated based on parameters other than the first coordinates. Here, the higher the degree of agreement, the higher the reliability, and the lower the degree of agreement, the lower the reliability.

[0108] As described in the above embodiment, the first coordinate is calculated based on the arrival angle of the wireless signal received by the vehicle-mounted device 200. Since the phase used to calculate the arrival angle of the wireless signal is prone to error, the first coordinate estimated based on the arrival angle may contain an error.

[0109] An example of a parameter other than the first coordinate is a distance measurement value calculated based on the ToF of the wireless signal. The coordinates of the portable device 100 and the presence area of ​​the portable device 100 can be roughly estimated by a combination of the coordinates of the vehicle-mounted device 200A and the distance measurement value obtained by the vehicle-mounted device 200A, and a combination of the coordinates of the vehicle-mounted device 200B and the distance measurement value obtained by the vehicle-mounted device 200B. Therefore, it is possible to evaluate the reliability of the first coordinate based on the degree of agreement between the presence area of ​​the portable device 100 estimated based on the first coordinate and the presence area roughly estimated based on the distance measurement value calculated based on the ToF of the wireless signal.

[0110] Another example of a parameter other than the first coordinate is the received signal strength of a wireless signal (e.g., Received Signal Strength Indicator (RSSI)). When the vehicle-mounted device 200 is placed inside the vehicle, it is possible to roughly estimate whether the presence area of ​​the portable device 100 is inside or outside the vehicle depending on whether the RSSI is greater than a certain threshold. Therefore, it is possible to evaluate the reliability of the first coordinate based on the degree of agreement between the presence area of ​​the portable device 100 estimated based on the first coordinate and the presence area roughly estimated based on the RSSI of the wireless signal.

[0111] <4. Supplementary Information> Although the preferred embodiment of the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention.

[0112] The series of processes by each device described in this specification may be realized using any of software, hardware, and a combination of software and hardware. The programs constituting the software are stored in advance, for example, in a recording medium (more specifically, a non-transient storage medium readable by a computer) provided inside or outside each device. Then, each program is read into a random access memory (RAM) when executed by a computer that controls each device described in this specification, and executed by a processing circuit such as a central processing unit (CPU). The recording medium is, for example, a magnetic disk, an optical disk, a magneto-optical disk, a flash memory, etc. The computer program may be distributed, for example, via a network without using a recording medium. The computer may be an application specific integrated circuit such as an application specific integrated circuit (ASIC), a general-purpose processor that executes a function by reading a software program, or a computer on a server used in cloud computing. The series of processes by each device described in this specification may be processed in a centralized manner by a single computer, or may be processed in a distributed manner by multiple computers. Furthermore, in each of the above embodiments, two or more communication means present in one device may be physically realized by one medium.

[0113] In addition, the processes described in this specification using flowcharts or sequence diagrams do not necessarily have to be performed in the order shown in the drawings. Some processing steps may be performed in parallel. In addition, additional processing steps may be employed, and some processing steps may be omitted. [Explanation of symbols]

[0114] 1: system, 100: portable device, 110: control unit, 120: wireless communication unit, 121: antenna, 20: vehicle, 200: vehicle-mounted device, 210: control unit, 220: wireless communication unit, 221: antenna, 300: control device, 310: control unit, 400: controlled device

Claims

1. a process of calculating, for each of a plurality of wireless communication units that wirelessly communicate with another communication device, coordinates indicating a position of the other communication device and a reliability parameter indicating reliability of the coordinates, based on wireless signals transmitted and received by each of the plurality of wireless communication units; a control unit that estimates an area where the other communication device is present by preferentially referring to the coordinates obtained by a wireless communication unit that has obtained a greater number of highly reliable coordinates among the plurality of wireless communication units from which the highly reliable coordinates have been obtained; A control device comprising:

2. When the number of highly reliable coordinates obtained by the plurality of wireless communication units is not equal, the control unit estimates the presence area of ​​the other communication device by preferentially referring to the coordinates obtained by the wireless communication unit that has obtained a greater number of highly reliable coordinates. The control device according to claim 1 .

3. The control unit estimates the presence area of ​​the other communication device based on a median value of a plurality of highly reliable coordinates. The control device according to claim 1 .

4. the control unit estimates the presence area of ​​the other communication device based on one of the highly reliable coordinates having the highest reliability among two or more highly reliable coordinates near a median value of the plurality of highly reliable coordinates; The control device according to claim 1 .

5. the control unit estimates the two or more presence areas of the other communication devices based on two or more highly reliable coordinates near a median value among the plurality of highly reliable coordinates; The control device according to claim 1 .

6. the control unit estimates the presence area of ​​the other communication device by taking a majority vote from a plurality of areas corresponding to each of a plurality of highly reliable coordinates. The control device according to claim 1 .

7. The control unit estimates the presence area of ​​the other communication device based on the coordinates obtained by the wireless communication unit when a certain threshold or more of the highly reliable coordinates are obtained. The control device according to claim 1 .

8. the control unit calculates the reliability parameter based on a degree of coincidence between the presence area of ​​the other communication device estimated based on the coordinates and the presence area of ​​the other communication device estimated based on parameters other than the coordinates. The control device according to any one of claims 1 to 7.

9. The control unit calculates the coordinates based on an angle of arrival of the wireless signal received by the wireless communication unit, The parameter other than the coordinates is a distance measurement value calculated based on a Time of Flight (ToF) of the wireless signal or a received signal strength of the wireless signal. The control device according to claim 8.

10. 1. A computer-implemented control method, comprising: repeatedly executing, for each of a plurality of wireless communication units that wirelessly communicate with another communication device, a process of calculating coordinates indicating a position of the other communication device and a reliability parameter indicating reliability of the coordinates, based on a wireless signal transmitted and received by each of the plurality of wireless communication units that wirelessly communicate with the other communication device; estimating an area where the other communication device is present by preferentially referring to the coordinates obtained by the wireless communication unit that has obtained a greater number of highly reliable coordinates among the plurality of wireless communication units that have obtained the highly reliable coordinates; A control method comprising:

11. Computer, a process of calculating, for each of a plurality of wireless communication units that wirelessly communicate with another communication device, coordinates indicating a position of the other communication device and a reliability parameter indicating reliability of the coordinates, based on wireless signals transmitted and received by each of the plurality of wireless communication units; a control unit that estimates an area where the other communication device is present by preferentially referring to the coordinates obtained by a wireless communication unit that has obtained a greater number of highly reliable coordinates among the plurality of wireless communication units from which the highly reliable coordinates have been obtained; A program to function as a

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