JP2016223942A - Distance estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distance estimation device capable of estimating highly accurately a distance between devices.SOLUTION: In a master, when a transmission line 4 is energized, a current amplitude distribution is changed continuously in the transmission line 4. A slave receives power corresponding to a current amplitude in prescribed regions R1-R3 generated in the transmission line 4. In this case, a charging part 12 of a power supply circuit 3f is charged with a signal received by the slave. A control part 19 estimates a distance between the master and the slave corresponding to a state of charge of the charging part 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a distance estimation device that estimates a distance between a power transmission device and a power reception device.

  For example, when a radio wave transmitter emits a radio wave and a radio wave receiver receives this radio wave, it uses the principle that the signal strength of the radio wave is attenuated in proportion to the square of the distance between the radio wave transmitter and the radio wave receiver. A technique for measuring the distance between the two has been developed (see, for example, Patent Document 1).

JP 2010-85273 A

  The inventors have changed the current amplitude distribution continuously in the power transmission path, for example, when the power transmission device supplies AC power to a power transmission line such as a harness, and the power receiving device has an electric field / We are developing technology to receive power by coupling magnetic fields. However, a technique for estimating the distance between the power transmission apparatus and the power reception apparatus has not been established, and the distance between the apparatuses cannot be estimated with high accuracy even when the technique described in Patent Document 1 is applied.

  The objective of this invention is providing the distance estimation apparatus which enabled it to estimate the distance between a power transmission apparatus and a power receiving apparatus as highly as possible.

  According to the first aspect of the present invention, when the power transmission device supplies AC power to the power transmission line, the current amplitude distribution continuously changes in the middle of the power transmission line. The power receiving device receives power according to a current amplitude in a predetermined region generated in the power transmission line. At this time, the charging unit charges a power reception signal received by the power receiving device. The estimation unit estimates a distance between the power transmission device and the power reception device according to a charging state of the charging unit.

  Since the current amplitude distribution changes continuously in the middle of the transmission line, the charging state of the charging unit varies depending on which region of the transmission line receives power. Therefore, the estimation unit can estimate the distance with high accuracy by estimating the distance between the power transmission device and the power reception device according to the charging state of the charging unit.

The block diagram which shows roughly the example of an electrical structure about 1st Embodiment The figure which shows roughly an example of the relationship between a transmission line and a receiving antenna Circuit diagram schematically showing a configuration example of a rectifier circuit A diagram showing the distribution of the feed current that changes depending on the area Timing chart schematically showing basic charge / discharge operations Timing chart schematically showing the voltage rising gradient in the region where the current amplitude of the transmission line is relatively low Timing chart schematically showing the voltage rising gradient in the region where the current amplitude of the transmission line is relatively high Timing chart schematically showing the measurement operation of the state of charge in the second embodiment Flow chart explaining measurement operation

  Hereinafter, some embodiments of the distance estimation apparatus will be described with reference to the drawings. About the same or similar structure between each embodiment, the code | symbol same as the code | symbol attached | subjected to the previous embodiment is attached | subjected, description is abbreviate | omitted as needed in subsequent embodiment, and it demonstrates centering on a different part. .

(First embodiment)
1 to 7 are explanatory diagrams of the first embodiment. As shown in FIG. 1, a wireless power feeding system 1 includes a master (equivalent to a power transmission device) 2 and one or more (N: N ≧ 1) slaves (equivalent to a power receiving device) 101, 102,. Through an electric / magnetic field. A battery (not shown: power supply source) is connected to the master 2, and power is supplied to the plurality of slaves 101 to 110 through the transmission line 4 using the power of the battery, and the slaves 101 to 110 each time. Operates according to the supplied power. These slaves 101 to 110 are connected to loads 201 to 210 including sensors, actuators, control ICs, and the like, respectively, and supply power to the loads 201 to 210, respectively. The wireless power feeding system 1 is synonymous with a power line power feeding system.

  The master 2 is a control circuit 2a, a high-frequency power generation circuit 2b, a modulation / demodulation circuit 2c, a superposition / separation circuit 2d, a matching circuit 2e, and a storage unit that mainly perform communication with the slaves 101 ... 110 and control other functions. 2f is built in a device main body (master main body) 2g, and a transmission line (equivalent to a power transmission line) 4 is connected from the device main body 2g. The control circuit 2a is mainly composed of a microcomputer, for example. The high frequency power generation circuit 2b generates a high frequency signal (carrier wave signal) having a predetermined frequency in accordance with the control of the control circuit 2a, and outputs it as a power signal to the superposition / separation circuit 2d. The modulation / demodulation circuit 2c is a block that modulates communication data on the master side and outputs a signal to the superposition / separation circuit 2d. The modulation / demodulation circuit 2c modulates the carrier with the data output from the control circuit 2a on the master 2 side and superimposes it as a data modulation signal. / Output to separation circuit 2d. Here, the high frequency signal (carrier wave signal) output from the high frequency power generation circuit 2b is preset so that the data modulation signal output from the modulation / demodulation circuit 2c and its frequency band are different from each other.

  The superimposing / separating circuit 2d combines these carrier wave signals and data modulation signals and outputs them to the matching circuit 2e. The matching circuit 2 e sends out a carrier wave signal on which the data modulation signal is superimposed to the transmission line 4. The matching circuit 2e matches the impedance between the device body 2g and the transmission line 4. The control circuit 2a connects a control line to the modulation / demodulation circuit 2c so that the data modulation / demodulation method and data communication frequency of the modulation / demodulation circuit 2c can be controlled.

  FIG. 2 schematically shows a partial structure of the transmission line 4. The transmission line 4 is installed in a vehicle, for example, and is configured using a twisted pair cable (twisted pair cable). As shown in part in FIG. 2, the transmission line 4 has a pair of twisted wires formed by twisting a pair of power transmission lines 5 and 6 facing each other in a predetermined direction (one direction: for example, the X direction). It is extended and arranged (about several meters). The predetermined direction may include a direction of bending or bending.

  Further, the transmission line 4 is configured in a loop shape by a pair of twisted wires joined at the ends. The transmission line 4 includes a twisted portion 7 formed by twisting power transmission lines 5 and 6, and includes an opening 8 between adjacent twisted portions 7. Among the openings 8 between all adjacent twisted portions 7, an opening 8a between specific twisted portions 7a (hereinafter referred to as a specific opening 8a) is between the other twisted portions 7 or between the twisted portions 7 and 7a. Largely formed.

  The aperture antenna 3g of the slaves 101 to 110 is installed around the specific aperture 8a. The aperture antenna 3g is constituted by a loop-shaped coil provided with the aperture 9, and links the magnetic flux generated from the specific aperture 8a between the twisted portions 7a of the transmission line 4 to the aperture 9 of the power receiving antenna 3g. Thereby, the aperture antenna 3g can receive power from the transmission line 4 according to the electromagnetic induction phenomenon. Here, for example, the surface of the specific aperture 8a and the surface of the aperture 9 of the aperture antenna 3g may be arranged in parallel, for example, the aperture 9 of the aperture antenna 3g is installed so as to face the specific aperture 8a, for example. May be. 1 may be spaced apart in the XY direction as shown in the XY plane, or may be installed in the same region in the XY direction as shown in FIG. If the aperture 9 of the aperture antenna 3g is installed so as to face the specific aperture 8a, the magnetic flux interlinked with the aperture antenna 3g can be increased, and the transmission efficiency can be increased.

  As shown in FIG. 1, each of the slaves 101 to 110 includes the same functional block, and includes a control circuit (equivalent to an allocation unit) 3a, a modulation / demodulation circuit 3c, a superposition / separation circuit 3d, a matching circuit 3e, and a power supply circuit, respectively. 3f and a storage unit 3h are incorporated. An aperture antenna 3g is connected to the matching circuit 3e.

  The matching circuit 3e is a matching circuit including, for example, a capacitor connected in parallel or in series with the aperture antenna 3g, and is configured to match impedance with the aperture antenna 3g. When the matching circuit 3e receives a signal through the aperture antenna 3g, the matching circuit 3e outputs the signal to the superposition / separation circuit 3d.

  The superimposition / separation circuit 3d separates the carrier wave signal and the data modulation signal, outputs the carrier wave signal as a power AC signal to the power supply circuit 3f, and outputs the data modulation signal to the modulation / demodulation circuit 3c. The power supply circuit 3f supplies the stabilized power supply for operation obtained by rectifying and smoothing the power AC signal to the modulation / demodulation circuit 3c, the control circuit 3a, and the respective loads 201 to 210.

  FIG. 3 shows a main configuration of the power supply circuit 3f. As shown in FIG. 3, the power supply circuit 3 f includes a rectifying unit 10, a smoothing unit 11, a charging unit 12, a charge switching unit 13, a stabilized power supply unit 14, a threshold generation unit 15, a correction unit 16, a discharge switching unit 17, The comparison part 18 and the control part 19 as a time measurement part and an estimation part are provided. The rectifying unit 10 performs full-wave or half-wave rectification on the power AC signal separated by the superimposition / separation circuit 3 d and outputs the rectified signal to the smoothing unit 11. As shown in FIG. 3, for example, when the rectifying unit 10 is constituted by a diode D1 connected between the input terminals 20 and 21, half-wave rectification is performed. The smoothing unit 11 smoothes the rectified output from the rectifying unit 10. For example, as shown in FIG. 3, when the smoothing unit 11 includes a capacitor C <b> 1 connected between the input terminals 20 and 21, the rectified output of the rectifying unit 10 is converted into a direct current. The stabilized power supply unit 14 inputs the rectified and smoothed voltage to generate a stabilized power supply voltage, and the stabilized DC power supply voltage Vo is output to the modulation / demodulation circuit 3c and the output terminal 22 and 23 through the output terminals 22 and 23, respectively. It supplies to the control circuit 3a and each load 201-210.

  The voltage V1 smoothed by the smoothing unit 11 is input to the charging unit 12 through the charge switching unit 13. The charging unit 12 is configured by using, for example, a capacitor C2, and the charging switching unit 13 is configured by a resistor array in which a plurality of resistors R11 to R14 and a plurality of switches S1 to S4 are connected in series. These resistors R11 to R14 are adjusted in advance so that their resistance values are different from each other.

  The correction unit 16 is configured to be able to switch on and off the plurality of switches S1 to S4 independently. For example, when the correction unit 16 turns on the switch S1 and turns off the switches S2 to S4, the charging unit 12 charges the capacitor C2 with the voltage V1 through the resistor R11. When the correction unit 16 turns off the switches S1 to S3 and turns on the switch S4, the charging unit 12 charges the capacitor C2 with the voltage V1 through the resistor R14.

  The correction unit 16 is provided to correct the charging speed (time constant during charging) of the charging unit 12. For example, as illustrated in FIG. 3, when a plurality of resistors R11 to R14 of the charge switching unit 13 are connected in parallel, the correction unit 16 switches the on / off state of the plurality of switches S1 to S4 to thereby change the charging speed ( The time constant during charging can be corrected.

  The discharge switching unit 17 is configured by using the switch S5, and enables the charge voltage of the charging unit 12 to be switched. For example, the discharge switching unit 17 includes a switch S5 connected in parallel to both terminals of the capacitor C2. The control unit 19 can control the discharge by the discharge switching unit 17. When the control unit 19 instructs the discharge switching unit 17 to discharge, the charging voltage of the charging unit 12 is discharged through the switch S5 of the discharge switching unit 17.

  The threshold generation unit 15 generates a threshold Vth. The comparison unit 18 includes, for example, a comparator (not shown), compares the charging voltage (corresponding to the power reception signal) charged in the charging unit 12 with the threshold value Vth, and outputs the comparison result to the control unit 19. The comparison unit 18 compares the voltage Vch of the common connection node between the charge switching unit 13 and the charging unit 12 and the threshold value Vth, and outputs the comparison result to the control unit 19.

  The control unit 19 is configured by connecting a storage unit 3h (see FIG. 1). The storage unit 3h is configured by various memories such as a register, a RAM, a ROM, or an EEPROM, for example, and a relational expression for calculating a distance according to a predetermined parameter (for example, a time until the threshold value Vth is reached), or A storage area such as a lookup table (LUT) that stores the relationship between the parameter and the distance is provided. The control unit 19 estimates the distance between the master 2 and the slaves 101 to 110 based on the storage content of the storage unit 3h and the comparison result of the comparison unit 18, and this operation will be described later. The control part 19 outputs the estimation result of the distance between master slaves to the control circuit 3a. The control circuit 3a allocates the identification codes of the slaves 101 to 110 based on the distance estimation result and stores them in the storage unit 3h. The distance estimation result is used as a temporary identification code, and the allocation result is sent to the master 2. The data for transmission.

  On the other hand, the modem circuit 3c operates with the stabilized power supplied from the power supply circuit 3f, demodulates the data modulation signal transmitted from the superimposition / separation circuit 3d, and outputs the demodulated data to the control circuit 3a. The control circuit 3a operates with the power supplied from the power supply circuit 3f and receives the demodulated data from the modulation / demodulation circuit 3c. Thereby, data can be transmitted from the master 2 to the slaves 101 to 110.

  Conversely, when data is transmitted from the slave 110 to the master 2, the operation is as follows. The control circuit 3a of the slave 110 modulates data by the modulation / demodulation circuit 3c and transmits this data modulation signal to the superimposition / separation circuit 3d. The superimposing / separating circuit 3d superimposes the data modulation signal of the modulation / demodulation circuit 3c on the carrier wave signal and outputs it to the matching circuit 3e. The matching circuit 3e outputs a carrier wave signal on which the modulation signal is superimposed to the transmission line 4, and the transmission line 4 outputs it as a radio wave signal.

  When the master 2 receives this signal through the transmission line 4, it receives it through the matching circuit 2e and outputs it to the superposition / separation circuit 2d. The superimposition / separation circuit 2d separates the data modulation signals from the slaves 101 to 110 with a filter and outputs the signals to the modulation / demodulation circuit 2c. The modem circuit 2c demodulates data using the carrier and outputs it to the control circuit 2a. As a result, the master 2 can receive the allocation result to which the temporary identification codes of the slaves 101 to 110 are added.

The master 2 can make the slaves 101 to 110 correspond to the allocation result by storing the allocation result in the storage unit 2 f together with the temporary identification code received by the data.
An example of the distance estimation method in the above configuration will be described in detail. First, the current amplitude distribution through which the transmission line 4 is energized will be described with reference to FIG. When the high-frequency power generation circuit 2b outputs AC power based on a carrier wave signal to the transmission line 4 through the superposition / separation circuit 2d, a standing wave is generated in the transmission line 4. As for this standing wave, current amplitude distribution changes continuously in the transmission line 4, and each slave 101-110 receives electric power according to the current amplitude of predetermined area | region R1-R3 which arises in the transmission line 4. FIG.

  The example shown in FIG. 4 shows an example in which the value of the current amplitude is determined in a one-to-one correspondence with the regions R1 to R3 in the entire transmission line 4, from the master 2 toward the end of the transmission line 4. The current amplitude distribution of the line in which the current amplitude monotonously increases is shown. Note that any distribution line may be applied as long as the current amplitude distribution continuously changes between the minimum value and the maximum value in accordance with the region of the transmission line 4. At this time, the current amplitude changes continuously and greatly in accordance with the region of the transmission line 4 (see regions R1 to R3). For example, the current amplitude is relatively low in the region R1, while the current amplitude is relatively high in the region R3.

  The transmission line 4 radiates AC power mainly from the specific opening 8a when radiating power to the outside. The aperture antenna 3g can receive power by generating an electromotive force by linking the magnetic flux generated by the alternating magnetic field of the transmission line 4 to the aperture 9. This electromotive force is output to the power supply circuit 3f through the superposition / separation circuit 3d. The power supply circuit 3f rectifies by the rectifying unit 10, smoothes by the smoothing unit 11, and outputs the voltage V1. When the control unit 19 turns off the switch S5 and the correction unit 16 turns on the switch S1, a charging current flows into the charging unit 12 through the switch S1 (t0 in FIG. 5).

  Since the slaves 101 to 110 receive power by the aperture antenna 3g and the aperture antenna 3g according to the current amplitude generated in the transmission line 4, the voltage V1 is input to the power supply circuit 3f, and the charging unit 12 charges the current corresponding to the voltage V1 ( T0 to t2 in FIG. During this time, when the voltage Vch exceeds the threshold value Vth, the output of the comparison unit 18 changes from “L” to “H” (t1 in FIG. 5). Based on the comparison result of the comparison unit 18, the control unit 19 measures times t0 to t1 during which the output of the comparison unit 18 is held at “L”.

  At this time, since the slave 101 installed in the region R1 receives power by the aperture antenna 3g according to a relatively low current amplitude generated in the transmission line 4, the voltage amplitude input to the power supply circuit 3f is also relatively low. As shown in FIG. 6, since the voltage V1 becomes a relatively low voltage V1L, the rising gradient of the voltage Vch is also reduced. As a result, the time ta from when the charging unit starts charging the voltage V1 until the threshold value Vth is reached is relatively long.

  On the other hand, since the slave 102 installed in the region R2 receives power by the aperture antenna 3g according to a relatively high current amplitude generated in the transmission line 4, the voltage amplitude input to the power supply circuit 3f is also relatively high. As shown in FIG. 7, since the voltage V1 becomes a relatively high voltage V1H, the rising gradient of the voltage Vch increases. As a result, the time tb from when the charging unit 12 starts to charge the voltage V1 until the threshold value Vth is reached is relatively short.

  Thus, when the threshold value Vth is set to the same voltage in advance among the plurality of slaves 101, 102,..., 110, the time from when the charging unit 12 starts to charge the voltage V1 until the voltage Vch reaches the threshold value Vth. Is different between the slave 101 installed in the region R1 and the slave 102 installed in the region R2.

  As described above, in the storage unit 3h, a relationship between a parameter (for example, time) and a distance is stored in advance as a relational expression or a lookup table (LUT). In the slave 101 installed in the region R1, the charging time for the voltage Vch to reach the threshold value Vth is relatively long, ta. For this reason, when the current amplitude distribution is predetermined as shown in FIG. 5, the control unit 19 can estimate the distance between the master and slave as a relatively close distance.

  Further, in the slave 102 installed in the region R2, the charging time for the voltage Vch to reach the threshold value Vth is relatively short as tb. For this reason, the control part 19 estimates the distance between master slaves as a comparatively long distance. Therefore, the distance between the master and slave can be estimated with high accuracy according to the charging times ta and tb.

  The control circuit 3a assigns the identification codes of the slaves 101 to 110 based on the distance estimation result and stores them in the storage unit 3h, and uses the distance estimation result as a temporary identification code and sends the assignment result to the master 2. Credit data. By using the distance estimation result as a temporary identification code, it is possible to prevent competition of identification codes with other slaves as much as possible.

<Summary>
For example, in the technique of Patent Document 1, ranging to a target is performed based on the received electric field strength. However, since this technique targets a space as a transmission line, the received electric power intensity varies and high-precision ranging is performed. The problem that can not be.

  According to the present embodiment, when the master 2 energizes the transmission line 4 with AC power and the current amplitude distribution continuously changes in the transmission line 4, the slaves 101, 102,. The power is received according to the current amplitude of the predetermined region generated in FIG. At this time, the charging unit 12 charges the signals received by the slaves 101, 102,. The control units 19 of the slaves 101, 102,..., 110 estimate the distances between the master 2 and the slaves 101, 102,.

  Since the current amplitude distribution continuously changes in the middle of the transmission line 4, the charging state of the charging unit 12 varies depending on which region of the transmission line 4 has received power. Therefore, the control unit 19 can estimate the distance with high accuracy by estimating the distance between the master 2 and the slaves 101, 102,..., 110 according to the charging state of the charging unit 12. Since the control unit 19 estimates the distance according to the time measurement result charged in the charging unit 12, the distance can be specified with high accuracy.

(Second Embodiment)
8 and 9 show additional explanatory views of the second embodiment. 2nd Embodiment is equipped with the state measurement part which measures the charge state which the charging part charged the received power signal for the predetermined time defined beforehand, and according to the charging result measured by the state measurement part, a power transmission apparatus and a power receiving apparatus Features a feature to estimate the distance between.

  In the storage unit 3h, a relationship between a parameter (for example, voltage Vch) and a distance is stored in advance as a relational expression or a lookup table (LUT). In this embodiment, the control part 19 shown in FIG. 3 is used as a state measurement part.

  FIG. 8 schematically shows an operation timing chart. In the present embodiment, the period during which the control unit 19 is turning on the switch S1 is fixed as a predetermined period, and the charging unit 12 is turned on by turning off the switch S1 and turning on the switch S5 at the elapse timing of the period. Discharge the charging voltage. This charge / discharge control is repeated a plurality of times (all periods t21 to t28 in FIG. 8).

  Then, the control unit 19 activates the operation control signal of the comparison unit 18 in order to measure the charging state of the charging unit 12 at the elapse timing of the predetermined period. At this timing, the control unit 19 supplies the voltage Vch and a threshold value (corresponding to a predetermined value) ) Vth is compared (refer to the operation of the comparison unit 18 in FIG. 8). At this time, if the current amplitude of the transmission line 4 in the region where the slaves 101, 102,... 110 are installed is constant, the magnitude of the voltage V1 hardly changes. For this reason, when the charging unit 12 charges the capacitor C2 with the voltage V1, the same voltage Vch can be charged in any period (all periods t21 to t28 in FIG. 8).

  In the present embodiment, the control unit 19 variably controls the threshold value Vth generated by the threshold value generation unit 15 during these all periods t21 to t28. The threshold generation unit 15 is configured by, for example, an N-bit digital-analog converter (DAC), and changes the threshold Vth in the voltage range from the lower limit value Vdac_low to the upper limit value Vdac_high under the control of the control unit 19. Activates the comparator 18. The control algorithm is shown in FIG. First, the variables COUNT = 0, Vth_high = Vdac_high, and Vth_low = Vdac_low are set for the variables COUNT, Vth_high, and Vth_low inside the control unit 19 (T1 in FIG. 9). The controller 19 turns on the switch S1 and charges the capacitor C2 for a predetermined period, and then turns off the switch S1 to hold the voltage.

  The control unit 19 controls the threshold value Vth = (Vth_high−Vth_low) / 2 in the period t21 to t22 (T2 in FIG. 9). The comparator 18 compares the threshold value Vth with the voltage Vch (T3 in FIG. 9). At this time, when the threshold value Vth is lower than the voltage Vch, the comparison unit 18 outputs “H” (see the output of the comparison unit 18 at timing t22 in FIG. 8). Thereafter, the control unit 19 sets the lower limit value Vth_low = Vth (T4 in FIG. 9), increases the variable COUNT by 1 (T6 in FIG. 9), turns on the switch S5, and discharges the capacitor C2. The process is repeated until the upper limit of the variable COUNT = N-1 is satisfied (T7 in FIG. 9). However, since the variable COUNT is not N-1 in the initial period, the process returns to step T2 and repeats the process (NO in T7 in FIG. 9). ).

  Further, the control unit 19 controls the threshold Vth = (Vth_high−Vth_low) / 2 during the period t22 to t23, and the comparison unit 18 compares the threshold Vth with the voltage Vch. At this time, if the threshold value Vth exceeds the voltage Vch, the comparison unit 18 outputs “L” (see the output of the comparison unit 18 in the period t22 to t23 in FIG. 8). The control unit 19 sets the upper limit value Vth_high = Vth (T5 in FIG. 9) and increases the variable COUNT by 1 (T6 in FIG. 9). Thereafter, the control unit 19 changes the threshold value Vth generated by the threshold value generation unit 15 until the variable COUNT reaches N-1, and repeats this operation (periods t24 to t28 in FIG. 8). Thus, the threshold value Vth can be converged so as to coincide with the voltage Vch using a so-called binary search method (see the period t27 to t28 in FIG. 8), and the value of the voltage V1 = Vth = Vch can be calculated.

  At this time, the slave 101 installed in the region R1 receives power through the aperture antenna 3g according to a relatively low current amplitude generated in the transmission line 4. For this reason, the voltage amplitude input to the power supply circuit 3f is also relatively low. As shown in FIG. 6, since the voltage V1 is a relatively low voltage V1L, the voltage Vch is also relatively small.

  On the other hand, the slave 102 installed in the region R2 receives power through the aperture antenna 3g according to a relatively high current amplitude generated in the transmission line 4. For this reason, the voltage amplitude input to the power supply circuit 3f also becomes relatively high. As shown in FIG. 7, since the voltage V1 is a relatively high voltage V1H, the voltage Vch is also relatively large.

  When the method of this embodiment is used, the voltage Vch can be converged and calculated using the binary search method in each of the slaves 101, 102,. As described above, the relationship between the parameter (for example, voltage Vch) and the distance is stored in advance as a relational expression or a look-up table (LUT) in the storage unit 3h. In the slave 101 installed in the region R1, the voltage Vch is detected to be relatively small. For this reason, when the current amplitude distribution is predetermined as shown in FIG. 5, the control unit 19 can estimate that the distance between the master and the slave is relatively close.

  In the slave 102 installed in the region R2, the voltage Vch is detected to be relatively large. For this reason, the control part 19 can estimate that it is a comparatively long distance between master slaves. Therefore, the distance between the master and the slave can be estimated with high accuracy according to the detection result of the voltage Vch.

According to the present embodiment, since the control unit 19 estimates the distance based on the voltage Vch (corresponding to the charging state) charged by the charging unit 12 during a predetermined time, the distance between the master and slave is highly accurate. Can be estimated. In this embodiment, it is not necessary to provide a time measuring device (for example, a counter) in the control unit 19.
In the present embodiment, the threshold value Vth may not be set to the same voltage between the slaves 101, 102,.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and the configurations of the embodiments can be combined, and various modifications or expansions can be made to the combined form of one or more embodiments. For example, the following modifications or expansions can be made.

The transmission line 4 may be configured by connecting a terminator composed of a resistor, a short-circuit line, or the like to a part (end) thereof.
In the first embodiment, the control unit 19 of the slaves 101, 102,..., 110 performs distance estimation processing. However, for example, information on the charging state of the voltage Vch or / and the voltage Vch reaches the threshold value Vth. , 110, and so on, data is transmitted from the slaves 101, 102,..., 110 to the master 2, and the control circuit 2a of the master 2 is a distance between the master and slave based on at least one of the information. May be estimated.

  Also in the second embodiment, the control unit 19 of the slaves 101, 102,..., 110 performs the distance estimation process. However, for example, information on the charging state of the voltage Vch or / and the threshold Vth by the binary search method The slaves 101, 102,..., 110 transmit data to the master 2, and the control circuit 2a of the master 2 estimates the distance between the master and slave based on at least one of these information. Anyway.

The identification code allocation process may be performed on the master 2 side (for example, the control circuit 2a or the like: equivalent to the allocation unit) or on the slaves 101, 102,..., 110 side (for example, the control circuit 3a or the like: equivalent to the allocation unit). good.
When performing the distance estimation process, the load 201 to 210 is disconnected from the output of the stabilized power supply, and the distance between the master and slave is estimated with a load (for example, a resistor) having a known impedance connected. good.

  If it is not necessary to assign the identification code to the slaves 101, 102,..., 110 based on the distance estimation process, the modulation / demodulation circuit 2c and superimposition / separation circuit 2d of the master 2 and the slaves 101, 102,. The modulation / demodulation circuit 3c and superposition / separation circuit 3d 110 may be omitted, and the present invention may be applied to a form in which data communication is not performed between master slaves. The configurations of the embodiments can be applied in appropriate combinations.

  In the drawings, 2 is a master (power transmission device), 2a is a control circuit (estimation unit, allocation unit), 3g is an aperture antenna, 4 is a transmission line (power transmission line, a pair of twisted wires), 12 is a charging unit, and 19 is a control unit. , 110 are slaves (power receiving devices), and R1, R2, and R3 are regions (predetermined regions).

Claims (8)

The power transmission device (2) is configured such that when the power transmission line (4) is energized, the current amplitude distribution continuously changes in the power transmission line, and the power reception devices (101, 102,..., 110) are configured as described above. Is configured to receive power according to the current amplitude of a predetermined region (R1, R2, R3) generated in
A charging unit (12) for charging a power receiving signal received by the power receiving device;
An estimation unit (19, 2a) for estimating a distance between the power transmission device and the power reception device according to a charging state of the charging unit;
A distance estimation apparatus comprising: The distance estimation apparatus according to claim 1,
The transmission line is a distance estimation device in which the region and current amplitude are set in a one-to-one relationship in the entire transmission line. The distance estimation apparatus according to claim 1 or 2,
The power transmission line is a distance estimation device configured to extend in one direction by a pair of twisted wires (4) formed in a loop shape with end portions coupled. The distance estimation apparatus according to claim 3,
The power transmission device supplies AC power to the power transmission line, and the power reception device includes an aperture antenna (3g) configured to interlink a magnetic flux generated between adjacent twist portions of the pair of twisted wires. Estimating device. In the distance estimation apparatus as described in any one of Claim 1 to 4,
A distance estimation device further comprising an allocation unit (3a, 2a) that allocates an identification code to the power receiving device according to a distance estimation result by the estimation unit. In the distance estimation apparatus according to any one of claims 1 to 5,
A time measuring unit (19) for measuring the time until the charging unit charges the power reception signal to a predetermined value;
The said estimation part is a distance estimation apparatus which estimates the distance between the said power transmission apparatus and the said power receiving apparatus according to the time measurement result by the said time measurement part. In the distance estimation apparatus according to any one of claims 1 to 5,
The charging unit further includes a state measuring unit (19) for measuring a charging state in which the power reception signal is charged during a predetermined time.
The said estimation part is a distance estimation apparatus which estimates the distance between the said power transmission apparatus and the said power receiving apparatus according to the charging result measured by the said state measurement part. The distance estimation apparatus according to any one of claims 1 to 6,
The plurality of power receiving devices are configured to receive power according to the current amplitude of the power transmission line in different areas,
The estimation unit is a distance estimation device that estimates a distance between the power transmission device and the plurality of power reception devices.

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