JP3731335B2 - Distance measuring system and distance measuring machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a distance measuring system that includes a transmitter, a repeater, and a distance measuring device, and measures a distance from a reference point. The present invention also relates to a distance measuring device that measures the distance from the reference point.
[0002]
[Prior art]
Conventionally, a distance measuring system and a distance measuring machine capable of measuring one's position using radio waves are known. In such a distance measuring system, usually, radio waves are transmitted from three or more transmitters in synchronization, and the radio waves are received by the distance measuring device, and information necessary for position calculation is analyzed from a phase difference, etc. Furthermore, while obtaining support such as map information, it calculates its own position and calculates the distance from the reference point. Further, a reference signal may be transmitted from the distance measuring device, and after receiving the reference signal by the relay device, the relay signal may be returned.
[0003]
On the other hand, when such a distance measuring system is used for the purpose of navigating a ship or military applications, very high accuracy is required. On the other hand, in recent years, there is an increasing need to use a distance measurement system in various fields such as leisure purposes, for example, an application for measuring a position on a golf course. When a distance measurement system is introduced in such a field, it is not required to measure the distance with high accuracy, but it is indispensable to reduce the cost and size of the device.
[0004]
[Problems to be solved by the invention]
However, in a system that transmits radio waves from three or more transmitters as described above, it is necessary to synchronize the clocks in the plurality of transmitters very accurately in order to calculate an accurate distance. Also, when used in a wide area, it is necessary to increase the output from the transmitter. Therefore, the system configuration is complicated and it is difficult to reduce the cost.
[0005]
Also, when configuring a system with a distance measuring device and a repeater, it is necessary to transmit radio waves from the distance measuring device, so the distance measuring device becomes expensive and power consumption increases. Is limited, and miniaturization becomes difficult. Moreover, when many distance measuring devices are used simultaneously, there exists a possibility of interfering with each other.
[0006]
Therefore, in a conventional distance measuring system, for example, when applied to a simple distance measurement in a golf course, etc., it is possible to provide a user-friendly distance measuring device that satisfies both the cost reduction and downsizing requirements of equipment. The problem is that is difficult.
[0007]
Accordingly, the present invention has been made in view of the above-described problems, and the problem is to provide a distance measuring system and a distance measuring machine that can easily realize cost reduction and downsizing of a device with a simple configuration. is there.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problem, a distance measuring system according to claim 1 includes a transmitter that transmits a transmission radio wave of a first frequency, and a relay that receives the transmission radio wave and transmits a transmission radio wave of a second frequency. And a distance measuring system that receives the transmission radio wave of the first frequency and the transmission radio wave of the second frequency, wherein the transmitter transmits the first frequency with a predetermined reference signal Modulation means for modulating a signal; and first transmission means for wirelessly transmitting the modulated transmission signal, wherein the relay receives a transmission signal of the first frequency wirelessly transmitted by the transmitter. 1 reception means, conversion means for converting the frequency of the received reception signal of the first frequency to generate a transmission signal of the second frequency, and second transmission for wirelessly transmitting the generated transmission signal of the second frequency With means and before The distance measuring device receives a transmission signal of the first frequency wirelessly transmitted by the transmitter and demodulates the reference signal; and transmits the second frequency wirelessly transmitted by the repeater Detecting a phase difference between the third receiving means for receiving the signal and demodulating the reference signal, and the reference signal demodulated by the second receiving means and the reference signal demodulated by the third receiving means And detecting means for calculating a distance between the position of the transmitter and the position of the distance measuring device based on the detected phase difference.
[0009]
According to the first aspect of the present invention, in the transmitter, the first frequency transmission signal modulated by the modulation means with the predetermined reference signal is wirelessly transmitted by the first transmission means.
[0010]
In the repeater, after the first frequency transmission signal transmitted from the transmitter is received by the first receiving means, the frequency is converted by the converting means to generate a second frequency transmission signal. The second frequency transmission signal is transmitted by the second transmission means.
[0011]
In the distance measuring device, the first frequency transmission signal transmitted from the transmitter is received by the second receiving means, and the second frequency transmission signal transmitted from the relay is received by the third receiving means, In both cases, the reference signal is demodulated. Then, the phase difference between the two reference signals is detected by the detecting means, and the distance between the transmitter and the distance measuring device is calculated by the calculating means based on the result.
[0012]
Therefore, since the transmission signal from the transmitter and the relay signal are used, accurate synchronization between the devices is not necessary, and the distance measuring device only needs to receive them, so there is no need to output the transmission signal. Therefore, the configuration of the distance measuring system is simplified, and the distance measuring device is low cost and low power consumption.
[0013]
A distance measuring system according to a second aspect is the distance measuring system according to the first aspect, characterized in that the repeater is installed in a fixed position and the transmitter is installed in a moving body.
[0014]
According to the second aspect of the present invention, the position of the repeater is fixed among the transmitter, the repeater, and the distance measuring device, but the transmitter is installed on the moving body and is movable. Yes.
[0015]
Therefore, on the condition that the initial position of the transmitter is known, the distance measurement can be performed, for example, by installing the transmitter inside the golf ball, so that the convenience of the distance measurement system is further increased. Get higher.
[0016]
The distance measuring system according to claim 3 is the distance measuring system according to claim 1 or 2, wherein the distance measuring device includes a position direction of the transmitter with a position of the distance measuring device as a reference point. The apparatus further includes setting means for setting an angle formed with the position direction of the repeater, and the calculating means calculates the distance based on the phase difference and the set angle.
[0017]
According to the third aspect of the present invention, the angle at which the transmitter and the repeater are viewed with reference to the distance measuring device is set by the setting means, and the calculation means is calculated from the angle and the phase difference detected by the detection means. Is used to calculate the distance.
[0018]
Therefore, even when the distance measuring device moves through a complicated route, the angle is set by a simple means, and the distance is thereby obtained, thereby further increasing the availability of the distance measuring system.
[0019]
5. The distance measuring device according to claim 4, wherein the transmitter transmits a transmission radio wave having a first frequency modulated by a predetermined reference signal, and a relay device that receives the transmission radio wave and transmits a transmission radio wave of a second frequency. And a distance measuring device in a distance measuring system comprising a distance measuring device that receives a transmission radio wave of the first frequency and a transmission radio wave of the second frequency, wherein the first frequency wirelessly transmitted by the transmitter Second receiving means for demodulating the reference signal by receiving the transmission signal, and third receiving means for demodulating the reference signal by receiving the transmission signal of the second frequency wirelessly transmitted by the repeater; Detecting means for detecting a phase difference between the reference signal demodulated by the second receiving means and the reference signal demodulated by the third receiving means; and based on the detected phase difference, the transmitter And the position of Characterized in that it comprises a calculating means for calculating the distance between the position of the serial distance measuring.
[0020]
According to the fourth aspect of the present invention, the first frequency transmission signal transmitted from the transmitter is received by the second receiving means, and the second frequency transmission signal transmitted from the repeater is third received. And the reference signal is demodulated together. Then, the phase difference between the two reference signals is detected by the detecting means, and the distance between the transmitter and the distance measuring device is calculated by the calculating means based on the result.
[0021]
Therefore, since the distance measuring device only needs to receive two transmission signals, there is no need to output a transmission signal by itself. Therefore, the distance measuring device can measure the distance more easily, and is low cost and low power consumption.
[0022]
The distance measuring device according to claim 5 is the distance measuring device according to claim 4, wherein an angle formed between a position direction of the transmitter and a position direction of the repeater with the position of the distance measuring device as a reference point. Setting means for setting is further provided, wherein the calculation means calculates the distance based on the phase difference and the set angle.
[0023]
According to the fifth aspect of the present invention, the angle at which the transmitter and the repeater are viewed with reference to the distance measuring device is set by the setting means, and the calculation means is calculated from the angle and the phase difference detected by the detection means. Is used to calculate the distance.
[0024]
Therefore, even when the distance measuring device moves through a complicated route, the angle is set by a simple means, and the distance is thereby obtained, thereby further increasing the availability of the distance measuring device.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to FIGS. The embodiment described below is an embodiment when the distance measuring system and the distance measuring device according to the present invention are applied to the distance measuring system and the distance measuring device for measuring the distance at the golf course. is there.
[0026]
As shown in FIG. 1, the distance measuring system according to the present embodiment receives a transmitter 1 that wirelessly transmits a reference transmission signal at a frequency f1, a transmission signal having a frequency f1 from the transmitter 1, and a frequency f2. A relay 2 that converts the signal into a relay signal for transmission, a transmission signal that is transmitted from the transmitter 1, and a relay signal that is transmitted from the relay 2 are received from the phase difference of the demodulated reference signal, respectively. It is comprised from the distance measuring device 3 which calculates. In FIG. 1, the transmitter 1 is placed at position B, the repeater 2 is placed at position A, and the distance measuring device 3 is placed at position C. The distance a connecting the position A and the position B is a known value, and the distance x connecting the position A and the position C and the distance y connecting the position B and the position C are values to be obtained. .
[0027]
Here, the configuration of the transmitter 1 will be described with reference to FIG. As shown in FIG. 2, the transmitter 1 includes a reference signal generator 11, an oscillator / modulator 12, a power amplifier 13, and an antenna 14.
[0028]
In the above configuration, the reference signal generator 11 generates a reference signal having a predetermined pattern that provides a reference for phase difference detection in the distance measuring device 3. The reference signal is a pulse wave having a pattern as shown in FIG. 5A, for example, and may be generated continuously or intermittently at an appropriate timing. Further, the pattern of the reference signal may be a pattern representing certain information such as golf hole number data.
[0029]
The oscillator / modulator 12 oscillates at the first frequency f 1 transmitted from the transmitter and received by the repeater 2 and the distance measuring device 3, and this oscillation output is modulated by the reference signal output from the reference signal generator 11. To do. As the oscillator / modulator 12, for example, a voltage controlled oscillator can be used, and feedback control is performed so that a frequency is always f1 by applying a DC voltage. Furthermore, if the reference signal generated from the reference signal generator 12 is superimposed on this DC voltage, frequency modulation can be easily performed.
[0030]
The power amplifier 13 amplifies the signal having the frequency f1 modulated by the reference signal with an appropriate gain. Then, the output of the power amplifier 13 is transmitted from the antenna 14 as a radio wave.
[0031]
Next, the configuration of the repeater 2 will be described with reference to FIG. As shown in FIG. 3, the repeater 2 includes an antenna 21, an antenna duplexer 22, a low noise amplifier 23, a mixer 24, a local oscillator 25, and a power amplifier 26.
[0032]
In the above configuration, the antenna 21 receives the transmission radio wave having the frequency f <b> 1 transmitted from the transmitter 1. Here, in the repeater 2, the antenna 21 is shared not only for reception from the transmitter 1 but also for transmission to the distance measuring device 3. Therefore, the received signal is input to the low noise amplifier 23 through the antenna duplexer 22 and amplified with a predetermined gain.
[0033]
The mixer 24 mixes the amplified signal with the frequency f1 with the signal from the local oscillator 25 and converts it to a signal with the frequency f2. Here, the frequency f2 is given by the sum of the frequency f1 and the frequency Δf of the local oscillator 25, and the relationship f2 = f1 + Δf is established.
[0034]
The power amplifier 26 amplifies the signal of the frequency f2 output from the mixer 24 with a predetermined gain. The output of the power amplifier 26 is transmitted as a radio wave from the antenna 21 through the antenna duplexer 22.
[0035]
Here, the antenna duplexer 22 has such characteristics that the frequency f1 is a pass band and the frequency f2 is a stop band on the reception side, while the frequency f2 is a pass band and the frequency f1 is a stop band on the transmission side. It is composed of filters.
[0036]
The mixer 24 may output a difference instead of the sum of the frequency f1 and the frequency Δf of the local oscillator 25. That is, the signal may be converted into a signal having a frequency f2 that satisfies the relationship f2 = f1−Δf.
[0037]
Next, the configuration of the distance measuring device 3 will be described with reference to FIG. As shown in FIG. 4, the distance measuring device 3 includes an antenna 31 and an antenna duplexer 32. Low noise amplifiers 33 and 43, down converters 34 and 44, local oscillators 35 and 45, demodulators 36 and 46, a phase difference detector 38, and an arithmetic unit 40 are provided.
[0038]
In the above configuration, the transmission radio wave having the frequency f1 transmitted from the transmitter 1 is received by the antenna 31, is input to the low noise amplifier 43 through the antenna duplexer 32, and is amplified with a predetermined gain. The down converter 44 converts the amplified signal having the frequency f1 into an intermediate frequency that is a difference frequency from the signal from the local oscillator 45, and outputs the intermediate frequency.
[0039]
On the other hand, the transmission radio wave having the frequency f2 transmitted from the repeater 2 is received by the antenna 31, is input to the low noise amplifier 33 through the antenna duplexer 32, and is amplified by a predetermined gain. The down converter 34 converts the amplified signal of the frequency f2 into an intermediate frequency that is a difference frequency from the signal from the local oscillator 35, and outputs it.
[0040]
The output signal of the down converter 44 is demodulated by the demodulator 46 and the standard signal S1 is extracted, and the output signal of the down converter 34 is demodulated by the demodulator 36 and the standard signal S2 is extracted. Here, the oscillation frequencies of the local oscillators 35 and 45 are determined so that the output signals of the down converters 44 and 34 have the same intermediate frequency.
[0041]
Thereafter, the standard signal S1 and the standard signal S2 are input to the phase difference detector 38. Here, the standard signals S1 and S2 are signals obtained by restoring the reference signal generated by the reference signal generator 11, but have different delays due to the difference in radio propagation path and frequency conversion. There is a certain phase difference. Therefore, this phase difference detector 38 detects and outputs this phase difference. This phase difference is input to the computing unit 40, and the distance to be obtained can be calculated according to the calculation described later.
[0042]
Here, since both the demodulator 36 and 46 are used at the same intermediate frequency, by using one having the same characteristics, the phase delay accompanying the demodulation in the standard signals S1 and S2 can be canceled each other, and the phase difference detector 38 is used. It is possible to prevent the detection by.
[0043]
Further, the phase difference detector 38 may measure the time difference at the rising edge of the pulse waveform of the reference signal after demodulation, for example. At this time, it can be detected using various methods such as counting the number of reference clock pulses between the rising edges of both pulse waveforms, or charging the capacitor with a predetermined current during this time and obtaining the charge voltage.
[0044]
In this embodiment, the down converters 34 and 44 convert the signal to an intermediate frequency once, and then the demodulator 36 and 46 demodulate the signal. However, the received signals of the frequencies f1 and f2 are directly demodulated. It may be configured. In this embodiment, the frequencies f1 and f2 are converted to the same intermediate frequency, but may be converted to two different intermediate frequencies.
[0045]
Next, the principle of the distance measuring method according to the present embodiment will be described with reference to FIGS.
[0046]
FIG. 5A shows a waveform pattern of the reference signal generated by the reference signal generator 11 of the transmitter 1. A transmission signal having a frequency f1 modulated by the reference signal is transmitted to the repeater 2 and the distance measuring device 3.
[0047]
The transmission signal transmitted from the transmitter 1 is received by the repeater 2 with a delay of time t1, as shown in FIG. 5 (b). Further, as shown in FIG. 5 (d), the distance measuring device 3 receives the signal with a delay of time t3, and further adds a delay of time t5 required for demodulation to obtain the standard signal S1.
[0048]
In the repeater 2, the received signal is converted into a transmission signal having the frequency f2. As shown in FIG. 5C, the transmission signal having the frequency f2 is transmitted after being delayed by a time t2 required for the frequency conversion. The
[0049]
On the other hand, in the distance measuring device 3, as shown in FIG. 5 (e), the transmission signal transmitted from the repeater 2 is received with a delay of time t4, and a delay of time t5 required for demodulation is added. A standard signal S2 is obtained.
[0050]
From the above, in the standard signal S1, a similar waveform is obtained with a delay of t3 + t5 from the change timing of the reference signal of the transmitter 1, whereas in the standard signal S2, the change of the reference signal of the transmitter 1 is obtained. From this timing, a similar waveform is obtained with a delay of t1 + t2 + t4 + t5. Therefore, the difference Δt between both delay times is
[Expression 1]
Δt = t1 + t2 + t4 + t5- (t3 + t5) = t1 + t2 + t4-t3
Given in. This Δt can be obtained by the phase difference detector 38 of the distance measuring device 3 as described above.
[0051]
Here, as shown in FIG. 6, the transmitter 1 is located at the position B, the repeater 2 is located at the position A, the distance measuring device 3 is located at the position C, and the distance between the position A and the position C is expressed as x. The distance between the position B and the position C is y, and the distance between the position A and the position B is a. Further, it is assumed that the three points A, B, and C form angles α, β, and γ, respectively, as shown in FIG.
[0052]
As described above, since the delay due to transmission from the repeater 2 to the distance measuring device 3 is t4, the distance x uses the speed of light c,
[Expression 2]
x = c × t4
It is expressed.
[0053]
Further, since the delay due to transmission from the transmitter 1 to the distance measuring device 3 is t3, the distance y is
[Equation 3]
y = c × t3
It is expressed.
[0054]
The difference b between the distance x and the distance y is
[Expression 4]
b = c (t4-t3)
It becomes.
[0055]
Further, in FIG. 6, the following four expressions hold.
[0056]
[Equation 5]
xsinα = ysinβ
[Formula 6]
xcosα + ycosβ = a
[Expression 7]
x−y = b
[Equation 8]
α + β = π-γ
Here, in the present embodiment, in the golf course, the transmitter 1 is fixedly provided at the position where the player begins to hit, the relay machine 2 is provided in the vicinity of the hole, and the distance measuring device 3 is moved while the player moves. It is used by carrying. That is, the distance a connecting the transmitter 1 and the repeater 2 can be measured in advance and set by the distance measuring device 3. At this time, the delay t1 from the transmitter 1 to the repeater 2 is also determined. Furthermore, t2 can be measured in advance, and t4-t3 in Equation 4 is obtained from Δt and t1, t2 from Equation 1, and b is determined. Here, if the angle γ is known, in the simultaneous equations of Equations 5 to 8, there are four unknowns x, y, α, and β, which can be solved.
[0057]
By the way, generally, when the transmitter 1 and the repeater 2 are installed as described above, the distance a connecting the vertical direction becomes very long, and the player moves greatly in the vertical direction along the distance a. In contrast, it moves only slightly in the lateral direction. Accordingly, there are many situations where the distance measuring device 3 is used at the position C where the angles α and β are close to 0 and the angle γ is close to 180 °.
[0058]
Therefore, in the calculations of Equations 5 to 8, it is conceivable that the angle α and the angle β are each approximated to 0 ° and the angle γ is approximated to 180 °. In this case, Equations 5 to 8 are simplified as follows.
[0059]
[Equation 9]
x + y = a
[Expression 10]
x−y = b
By solving Equations 9 and 10, the distance x from the distance measuring device 3 to the relay device 2 and the distance y from the distance measuring device 3 to the transmitter 1 can be easily calculated.
[0060]
On the other hand, when calculating the lateral movement of the player in the equations 5 to 8, it is necessary to give the angle γ by some method without using the above approximation. Even in this case, high accuracy is not required for simple distance calculation in a golf course, and it is sufficient to give an approximate angle. For example, a method may be used in which an approximate value of an angle is determined in advance for each predetermined range on the course and is selectively input to the distance measuring device 3. Thereby, simultaneous equations of Formulas 5 to 8 can be solved, and the distances x and y can be calculated easily.
[0061]
According to the distance measurement system according to the present embodiment, the phase difference based on the propagation delay and the like is detected based on the reference signal of the transmitter 1, so that the transmitter 1, the repeater 2, and the distance measurement device 3 are mutually accurate. You don't have to be synchronized. Therefore, the distance measuring system can be configured easily.
[0062]
In addition, since the distance measuring device 3 performs only reception and does not perform transmission, even when a plurality of distance measuring devices 3 are used at the same time in a certain area, they do not cause radio interference with each other. In addition, since there is no transmission unit, it is easy to reduce power consumption, and the battery can be used for a long time. Therefore, it is suitable for a player to carry and use the distance measuring device 3.
[0063]
Further, in a golf course composed of a large number of holes, one transmitter 1 and one repeater 2 can be installed for each hole. In this case, the transmitter 1 and the repeater 2 may change the frequency of the transmission signal for each hole so as to avoid mutual interference. On the other hand, the distance measuring device 3 is set so that the reception frequency is appropriately adapted to the transmission frequency of the transmitter 1 and the repeater 2 for each hole so that it can be used in any hole. For example, both the frequency used in each hall and the distance a may be stored in advance in the distance measuring device 3, and the stored content may be read and automatically set according to the hole number. Further, the distance information may be readable from the reference signal pattern of the transmitter 1. In this case, when the distance measuring device 3 demodulates the reference signal, the distance a is recognized, so that the distance calculation can be performed more easily.
[0064]
The preferred embodiments of the present invention have been described above. However, when the present invention is applied, various forms other than the above forms are conceivable. Hereinafter, useful modifications will be described.
[0065]
In the above embodiment, the case where the transmitter 1 and the repeater 2 are fixedly installed has been described. However, only the repeater 2 is fixedly installed, the transmitter 1 is installed on a moving body, and the distance measuring device 3 is installed. Similarly, it can be movable. For example, it is conceivable to install the transmitter 1 inside a golf ball.
[0066]
A specific example in this case will be described with reference to FIG.
[0067]
In FIG. 7, it is assumed that both the player carrying the distance measuring device 3 and the transmitter 1 inside the ball are at the position C immediately after the start of the game. The repeater 2 is installed at a position A near the hall. First, assume that the ball reaches position B when the player first hits the ball. In this case, as shown in FIG. 7, the transmitter 1 in the ball is at the position B, the repeater 2 is at the position A, and the distance measuring device 3 is at the position C.
[0068]
Here, when the distances x, y, a and the angles α, β, γ are given as shown in FIG. 7, unlike the case of FIG. 6, the distance x between the transmitter 1 and the repeater 2 is Since the position B of the transmitter 1 moves, it is unknown. Therefore, the delay t1 when transmitting from the transmitter 1 to the repeater 2 is also unknown. Therefore,
## EQU11 ##
t4 + t1-t3 = Δt-t2
To ask.
[0069]
The distance x from the repeater 2 to the transmitter 1 is
[Expression 12]
x = c × t1
The distance y from the transmitter 1 to the distance measuring device 3 is given by
[Formula 13]
y = c × t3
The distance a from the repeater 2 to the distance measuring device 3 is given by
[Expression 14]
a = c × t4
Given in. Here, b ′ is defined as follows.
[0070]
[Expression 15]
b '= c (t4 + t1-t3) = a + xy
In FIG. 8, the following simultaneous equations hold.
[0071]
[Expression 16]
xsinα = ysinγ
[Expression 17]
xcosα + ycosγ = a
[Formula 18]
x + a−y = b ′
Since the starting position is determined immediately after the start of the game, the distance a can be set by the distance measuring device 3 after being measured in advance. Therefore, if the angle γ is given, the simultaneous equations of Equations 16 to 18 can be solved.
[0072]
As in the case of FIG. 6, the calculation can be performed by a method such as approximating the angle γ or inputting it appropriately. When the angles α and γ are approximated to 0 °, the simultaneous equations of Equations 16 to 18 are simplified as follows.
[0073]
[Equation 19]
x + y = a
[Expression 20]
x−y = b′−a
By solving Equations 19 and 20, the distance x and the distance y can be easily calculated.
[0074]
Next, consider a case where the player moves to a position B where the ball is located and then hits the second shot. At this time, since the distance x is calculated as described above, the calculation may be performed after the value of x is updated in a. The third and subsequent shots can be similarly calculated, and the distance x and the distance y can be calculated every time.
[0075]
Further, when the player moves to the position B, the distance measurement may be performed again as described above. In this case, since the player once approaches the ball, the distance between the transmitter 1 and the distance measuring device 3 is almost zero as shown in FIG. Therefore,
[Expression 21]
x = b '/ 2
Therefore, even if the distance a from the starting position to the repeater 2 and the angle γ in FIG. 7 are unknown, the distance can be calculated.
[0076]
In addition, even if the transmitter 1 is not installed in the golf ball, the transmitter 1 may be movable and moved to the vicinity of the golf ball every time it is measured.
[0077]
Next, in the embodiment, the distance measuring device 3 is provided with the two local oscillators 35 and 45. However, these may be used in common, and frequency conversion for two signals may be simultaneously performed by one local oscillator. Good. In this case, the intermediate frequency is not the same in the receiving circuit on the frequency f1 side and the receiving circuit on the frequency f2 side, and is separated by the difference between f1 and f2, but if this difference is not large, the demodulation is performed. The standard signals S1 and S2 can be obtained under the same conditions. If the signal delay times are different in the demodulators 36 and 46, the time difference may be obtained in advance, and the calculation may be corrected in the arithmetic unit 40.
[0078]
Furthermore, although the case where the present invention is applied to a distance measurement system in a golf course has been described in the above embodiment, the present invention is not limited to this, and a transmitter and a relay can be installed. In addition, the present invention can be applied to a system that measures a distance using a distance measuring device in the vicinity of a straight line connecting a transmitter and a repeater.
[0079]
【The invention's effect】
According to the first aspect of the present invention, the first frequency transmission signal output from the transmitter and the second frequency transmission signal relayed by the relay device are received by the distance measuring device and the phase difference is received. Since the distance is calculated from the above, accurate synchronization between the devices is unnecessary, and the distance measuring device does not need to perform transmission. Therefore, the configuration of the distance measuring system is simplified, and the distance measuring device can be reduced in cost and power consumption.
[0080]
According to the second aspect of the present invention, the position of the repeater is fixed, and the transmitter is installed on the moving body and is movable. For example, the transmitter can be installed inside the golf ball, and the distance The convenience of the measurement system can be further enhanced.
[0081]
According to the third aspect of the present invention, since the angle setting means is provided, and the distance is calculated from the angle and the phase difference detected by the detection means, the distance measuring device moves through a complicated route. Even in this case, the distance is easily obtained, and the availability of the distance measurement system can be increased.
[0082]
According to the fourth aspect of the present invention, the first frequency transmission signal output from the transmitter and the second frequency transmission signal relayed by the relay device are received by the distance measuring device and the phase difference is received. Therefore, the distance measuring device does not need to perform transmission. Therefore, the distance measuring device can perform distance measurement more easily, and can reduce cost and power consumption.
[0083]
According to the fifth aspect of the present invention, the distance measuring device is provided with the angle setting means, and the distance is calculated from the angle and the phase difference detected by the detecting means. Even when moving through, the distance is easily determined, and the availability of the distance measuring device can be increased.
[Brief description of the drawings]
FIG. 1 is an overall view showing a distance measuring system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a transmitter according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a repeater according to an embodiment of the present invention.
FIG. 4 is a block diagram showing a configuration of a distance measuring device according to the embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a phase relationship of reference signals in the embodiment of the present invention.
FIG. 6 is an explanatory diagram showing the principle of distance measurement according to the present invention.
FIG. 7 is a first overall view showing a distance measuring system as a modification of the present invention.
FIG. 8 is a second overall view showing a distance measuring system as a modification of the present invention.
[Explanation of symbols]
1 ... Transmitter
2 ... Repeater
3 ... Distance measuring machine
11 ... Reference signal generator
24 ... Mixer
25, 35, 45 ... Local oscillator
36, 46 ... demodulator
38 ... Phase difference detector
40. An arithmetic unit.

Claims (5)

A transmitter that transmits a transmission radio wave of the first frequency, a relay that receives the transmission radio wave and transmits a transmission radio wave of the second frequency, a transmission radio wave of the first frequency, and a transmission radio wave of the second frequency A distance measuring system comprising a distance measuring device for receiving,
The transmitter is
Modulation means for modulating the transmission signal of the first frequency with a predetermined reference signal;
First transmitting means for wirelessly transmitting the modulated transmission signal,
The repeater is
First receiving means for receiving a transmission signal of the first frequency wirelessly transmitted by the transmitter;
Conversion means for converting the frequency of the received signal of the first frequency to generate the transmission signal of the second frequency;
Second transmission means for wirelessly transmitting the generated transmission signal of the second frequency,
The distance measuring machine is
Second receiving means for receiving the transmission signal of the first frequency wirelessly transmitted by the transmitter and demodulating the reference signal;
Third receiving means for receiving the transmission signal of the second frequency wirelessly transmitted by the repeater and demodulating the reference signal;
Detecting means for detecting a phase difference between the reference signal demodulated by the second receiving means and the reference signal demodulated by the third receiving means;
Calculation means for calculating a distance between the position of the transmitter and the position of the distance measuring device based on the detected phase difference;
A distance measuring system comprising: The distance measuring system according to claim 1, wherein the repeater is installed in a fixed position, and the transmitter is installed in a moving body. The distance measuring device further includes setting means for setting an angle formed by the position direction of the transmitter and the position direction of the repeater with the position of the distance measuring device as a reference point, and the calculating means includes the position The distance measurement system according to claim 1 or 2, wherein the distance is calculated based on a phase difference and the set angle. A transmitter that transmits a transmission radio wave of a first frequency modulated by a predetermined reference signal; a relay that receives the transmission radio wave and transmits a transmission radio wave of a second frequency; a transmission radio wave of the first frequency; A distance measuring device in a distance measuring system comprising a distance measuring device that receives a transmission radio wave of a second frequency,
Second receiving means for receiving the transmission signal of the first frequency wirelessly transmitted by the transmitter and demodulating the reference signal;
Third receiving means for receiving the transmission signal of the second frequency wirelessly transmitted by the repeater and demodulating the reference signal;
Detecting means for detecting a phase difference between the reference signal demodulated by the second receiving means and the reference signal demodulated by the third receiving means;
Calculation means for calculating a distance between the position of the transmitter and the position of the distance measuring device based on the detected phase difference;
A distance measuring machine comprising: The apparatus further includes setting means for setting an angle formed by the position direction of the transmitter and the position direction of the repeater with the position of the distance measuring device as a reference point, and the calculation means includes the phase difference and the set angle. The distance measuring device according to claim 4, wherein the distance is calculated based on the distance.

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