JP2020109370A - Out-of-view obstacle detecting system using frequency conversion - Google Patents

Abstract

To provide an obstacle detecting system capable of suppressing interference and oscillation.SOLUTION: An obstacle detecting system 1 comprises a vehicle communication unit 3 and an electric wave communication device 5. The vehicle communication unit comprises a first transmission unit 11 which transmits an electric wave, and a first reception unit 13 which receives the transmitted electric wave. The electric wave communication device comprises a second reception unit 21 which receives a first electric wave transmitted from the first transmission unit, a frequency conversion unit 23 which multiplies a frequency of the first electric wave received by the second reception unit by N (N is an integer of 2 and higher), a signal amplification unit 25 which amplifies a signal output from the frequency conversion unit, and a second transmission unit 27 which transmits a signal output from the signal amplification unit as a second electric wave. The vehicle communication unit uses a signal having a frequency of the first electric wave as a reference signal, and detects the electric wave communication device using the second electric wave received by the first reception unit and the reference signal.SELECTED DRAWING: Figure 1

Description

An aspect of the invention described in this specification relates to, for example, a system capable of notifying the presence of a person to a vehicle or a driver of the vehicle (vehicle or the like), and a portable terminal for causing the vehicle or the like to recognize the presence. ..

Japanese Unexamined Patent Application Publication No. 2018-36920 (Patent Document 1) describes an obstacle detection system outside the visual field.

JP, 2008-36920, A

The system described in Patent Document 1 is an excellent out-of-field obstacle detection system. However, this system has a problem that interference may occur or oscillation may occur.
Therefore, an aspect of the specification aims to provide an obstacle detection system capable of suppressing interference and oscillation, and to provide a mobile terminal effectively detected by the obstacle detection system.

One of the aspects described in this specification is that it is possible to prevent interference or oscillation in the vehicle communication unit by multiplying the frequency of the radio wave received by the radio communication device by N times, amplifying the frequency, and then transmitting. based on.

The above-described certain aspect relates to the obstacle detection system 1.
The obstacle detection system 1 includes a vehicle communication unit 3 and a radio wave communication device 5.
The vehicle communication unit 3 includes a first transmitting unit 11 that transmits a radio wave and a first receiving unit 13 that receives a radio wave.
The radio wave communication device 5 includes a second receiving unit 21, a frequency converting unit 23, a signal amplifying unit 25, and a second transmitting unit 27.
The second receiver 21 is an element for receiving the first radio wave transmitted from the first transmitter 11.
The frequency conversion unit 23 is an element for multiplying the frequency of the first radio wave received by the second reception unit 21 by N (N is an integer of 2 or more).
The signal amplifier 25 is an element for amplifying the signal output from the frequency converter 23.
The second transmitter 27 is an element for transmitting the signal output from the signal amplifier 25 as a second radio wave. The radio wave communication device 5 may be realized by a communication device or may be mounted by cooperation between the communication device and software.
Then, the vehicle communication unit 3 uses the signal having the frequency of the first radio wave or the signal obtained by multiplying the frequency of the first radio wave by N times (N is an integer of 2 or more) as a reference signal, and the first receiving unit A radio communication device is detected using the received second radio wave and the reference signal. In order to realize this function, the vehicle communication unit 3 may have a detection unit 15 for detecting a radio communication device. The detection unit 15 may be implemented by a computer, for example.

In one aspect of the obstacle detection system, the signal amplification unit 25 amplifies the signal output from the frequency conversion unit 23 by 40 dB or more. Generally, the intensity of the radio wave transmitted from the vehicle communication unit is attenuated before reaching the radio wave communication device 5. Therefore, the detection capability of the vehicle communication unit 3 can be enhanced by amplifying the signal extremely greatly.

In one aspect of the obstacle detection system, the frequency of the first radio wave is one type in a single time. Examples of such first radio waves are dual-frequency signals, multi-frequency signals, frequency sweep signals, or frequency hopping signals. In this way, by using radio waves of only one type of frequency in a single time, it is possible to measure the distance even using a multiplied signal.

In one aspect of the obstacle detection system, the radio communication device 5 further includes a filter 29 that transmits the frequency band of the first radio wave and the frequency band N times the frequency band of the first radio wave. The radio wave communication device 5 may include a filter that transmits the frequency band of the first radio wave and a filter that transmits the frequency band N times the frequency band of the first radio wave. The radio wave communication device 5 may also include one filter that transmits the frequency band of the first radio wave and the frequency band N times the frequency band of the first radio wave. Since such a filter 29 is included, it is possible to prevent a situation in which an unnecessary signal is amplified or a situation in which an unnecessary signal is transmitted.

One of the aspects described in this specification relates to a program installed in a mobile terminal such as the radio communication device 5. This program includes a signal converting means for converting a radio wave received by a receiving unit into an electric signal, a frequency converting means for multiplying a frequency of an output signal from the signal converting means by N (N is an integer of 2 or more), and a computer. It is a program that functions as a signal amplification unit that amplifies the signal output from the frequency conversion unit by 40 dB or more and a transmission unit that transmits the signal output from the signal amplification unit. A mobile terminal on which this program is installed has a computer and functions as the radio communication device described above.

This program causes the computer to further function as a frequency transmitting unit that transmits a signal in a predetermined frequency band among the output signals from the signal conversion unit and transmits a signal in a frequency band N times the predetermined frequency band. It is preferably one.

One of the aspects described in this specification relates to a mobile terminal.
This mobile terminal includes a signal conversion unit that converts the radio wave received by the receiving unit into an electric signal, a frequency conversion unit that multiplies the frequency of the output signal from the signal conversion unit by N (N is an integer of 2 or more), and frequency conversion. It has a signal amplification means for amplifying the signal output from the means by 40 dB or more, and a transmission means for transmitting the signal output from the signal amplification means.

According to a certain aspect described in this specification, it is possible to provide an excellent obstacle detection system capable of suppressing interference and oscillation, and a mobile terminal effectively detected by the obstacle detection system.

FIG. 1 is a conceptual diagram for explaining an obstacle detection system. FIG. 2 is a block diagram for explaining the function of the radio communication device. FIG. 3 is a flowchart showing an example of a detection process by the detection unit.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the modes described below, and includes those appropriately modified within the scope obvious to those skilled in the art from the following modes.

FIG. 1 is a conceptual diagram for explaining an obstacle detection system. As shown in FIG. 1, the obstacle detection system 1 includes a vehicle communication unit 3 and a radio wave communication device 5. The obstacle detection system 1 is used to avoid an obstacle and determine an appropriate course, especially in an autonomous vehicle. In the manned vehicle, the obstacle detection system 1 is used, for example, to notify a driver of an obstacle outside the visual field. As will be described later, the obstacle detection system 1 may include a distance measurement unit for obtaining the distance from the vehicle to the object (distance from the obstacle detection system to the object).

The vehicle communication unit 3 includes a first transmitting unit 11 that transmits a radio wave and a first receiving unit 13 that receives a radio wave. The first transmitter 11 and the first receiver 13 may be mounted by an antenna. The first transmitting unit 11 and the first receiving unit 13 may be connected to a control unit such as a computer and various calculations may be performed.

The vehicle communication unit 3 is a device that is mounted on the vehicle 33 and that generates radio waves. The vehicle communication unit 3 may be a mobile terminal or may include an in-vehicle computer. Examples of the vehicle 33 are self-driving cars, automobiles, work vehicles, and bicycles. For example, even if the driver of the vehicle has a mobile phone as the vehicle communication unit 3, the vehicle communication unit 3 is mounted on the vehicle 33 because the vehicle communication unit 3 moves together with the vehicle. The vehicle communication unit 3 is a device capable of transmitting (preferably and receiving) radio waves, and may be fixed to the vehicle or mounted on the vehicle.

In one aspect of the obstacle detection system, the frequency of the first radio wave is one type in a single time. The frequency of the first radio wave does not have to be fixed. For example, the frequency of the first radio wave may change over time. Examples of such first radio waves are dual frequency signals, multi-frequency signals, frequency sweep signals, or frequency hopping signals. The first radio wave may be a continuous signal or a pulse signal. When the first radio wave is a pulse signal, it is preferable that the pulse width be compressed when the pulse signal is raised to the Nth power (N is an integer of 2 or more). The dual frequency signal is a signal obtained by switching signals of two different frequencies in the time domain. The multi-frequency signal means a signal obtained by switching a plurality of frequency signals. This is also a signal in which components other than the component in which the frequency of the reference signal is an integral multiple are suppressed. The frequency sweep signal is a signal in which the first radio wave is a single signal at a certain time, but the frequency gradually increases or gradually decreases (or the signal repeatedly increases and decreases) as the time changes. The frequency hopping signal is a signal transmitted while switching the frequency of the output radio wave within a certain frequency band. Thus, by using radio waves of only one type of frequency in a single time, even if the frequency is multiplied, it is possible to prevent changes in the characteristics thereof, and as a result, it is possible to effectively prevent interference and oscillation. The distance can be measured by using only a single wavelength of the first radio wave. On the other hand, if multiple frequency signals are used, a wider range of distance can be measured. If the waveform does not generate multiple wavelengths at the same time, it is considered that there is no problem even if the reference signal is multiplied.

The first radio wave generated by the vehicle communication unit 3 is preferably a radio wave having a frequency below the microwave band. An example of this radio wave is the ISM band, and it is preferable that the radio wave is in the microwave band such as 2.4 GHz, 5 GHz, and 27 MHz. As will be described later, the radio communication device 5 is attached to the object 41 or is carried by the object 41. The radio wave communication device 5 receives the first radio wave output from the vehicle communication unit 3 and outputs the second radio wave.

As shown in FIG. 1, the radio communication device 5 of a certain aspect includes a second receiving unit 21, a frequency converting unit 23, a signal amplifying unit 25, and a second transmitting unit 27. The second receiver 21 and the second transmitter 27 can be mounted by the same or different antennas. The frequency conversion unit 23 and the signal amplification unit 25 may be implemented by a circuit or a computer.

FIG. 2 is a block diagram for explaining the function of the radio communication device.
In the example of FIG. 2, the second receiver 21 receives the first radio wave transmitted from the first transmitter 11. The received first radio wave is converted into an electric signal. Then, the converted electric signal passes through the bandpass filter 29. The bandpass filter transmits a signal in the frequency band of the preset first radio wave (and a signal in the frequency band N times that thereof) and suppresses signals in other frequency bands. The output from the bandpass filter 29 is output to the frequency conversion unit 23 via the circulator (or directional coupler) 53. In the frequency converter 23, the frequency of the first radio wave received by the second receiver 21 is multiplied by N (N is an integer of 2 or more). The frequency-converted electric signal is output to the signal amplifier 25. The signal amplification unit 25 receives the signal output from the frequency conversion unit 23, and the signal amplification unit 25 outputs the signal output from the frequency conversion unit 23 to 40 dB or more (for example, 50 dB or more and 150 dB or less, 50 dB or more and 100 dB or less, 60 dB. Above 100 dB or less, 70 dB or more and 90 dB or less, or 70 dB or more and 80 dB or less) is preferable. Generally, the intensity of the radio wave transmitted from the vehicle communication unit is attenuated before reaching the radio wave communication device 5. Therefore, the detection capability of the vehicle communication unit 3 can be enhanced by amplifying the signal extremely greatly.

In the mode shown in FIG. 2, the band filter 29 is included. However, the bandpass filter 29 is an optional element and may not be present. The bandpass filter in FIG. 2 is one filter that transmits the frequency band of the first radio wave and the frequency band N times the frequency band of the first radio wave. The bandpass filter 29 may be implemented by a filter that transmits the frequency band of the first radio wave and another (second) filter that transmits the frequency band N times the frequency band of the first radio wave. In any case, since such a filter 29 is included, it is possible to prevent a situation in which an unnecessary signal is amplified or a situation in which an unnecessary signal is transmitted. In particular, when N is 1, when a signal is amplified, an oscillation phenomenon occurs. Therefore, the oscillation phenomenon can be effectively prevented by amplifying the intensity after setting N to 2 or more.

The signal whose intensity has been amplified by the signal amplification unit 25 is transmitted to the second transmission unit 27 (antenna) via the circulator (or directional coupler) 53. The second transmitter 27 transmits the signal output from the signal amplifier 25 as a second radio wave. As described above, the radio wave communication device 5 may be realized by a communication device or may be mounted by cooperation between the communication device and software.

The radio wave communication device 5 is attached to the object 41 or carried by the object 41, receives the first radio wave output from the vehicle communication unit 3, and outputs the second radio wave. An example of the radio wave communication device 5 is a mobile phone, and may be a device attached to shoes or a bag (for example, a school bag) (for example, a sticker), and a device for a strap. The radio communication device 5 may be implemented by an application of a mobile terminal, for example. In other words, this application reads the information from the storage unit of the mobile terminal and transmits a predetermined signal to the output unit of the mobile terminal when the reception unit of the mobile terminal receives the radio wave from the radio communication device 5. Anything that can be controlled to.

One of the aspects described in this specification relates to a program installed in a mobile terminal such as the radio communication device 5. This program is implemented by a computer.

The computer has, for example, an input/output unit, a control unit, a calculation unit, and a storage unit. Then, when information is input from the input/output unit, the information is appropriately read from the storage unit based on the instruction of the control program stored in the storage unit, the arithmetic unit is caused to perform arithmetic processing, and the information is appropriately stored in the storage unit. Also, the computer is designed to be able to output a predetermined signal from the input/output unit.

This program includes a signal converting means for converting a radio wave received by a receiving unit into an electric signal, a frequency converting means for multiplying a frequency of an output signal from the signal converting means by N (N is an integer of 2 or more), and a computer. It is a program that functions as a signal amplification unit that amplifies the signal output from the frequency conversion unit by 40 dB or more and a transmission unit that transmits the signal output from the signal amplification unit. A mobile terminal on which this program is installed has a computer and functions as the radio communication device described above.

This computer may include an antenna and an element that changes a radio wave into an electric signal. In this case, the antenna may function as the input/output unit of the computer. A typical mobile terminal includes such a communication device. The first radio wave received by the antenna is converted into an electric signal. The computer stores the electric signal in the storage unit. The computer reads N related to the multiplication number from the storage unit. Then, the computer reads the electric signal corresponding to the received first radio wave and causes the arithmetic unit to perform the arithmetic operation for multiplying the frequency by N times. The computer stores in the storage unit a signal in which the frequency of the first radio wave obtained by the calculation unit is N times. The computer controls the antenna so as to amplify and output the strength of the signal in which the frequency of the first radio wave is N times. In this way, the intensity of the signal is amplified, and the signal whose frequency has become N times is output from the antenna.

This program causes the computer to further function as a frequency transmitting unit that transmits a signal in a predetermined frequency band among the output signals from the signal conversion unit and transmits a signal in a frequency band N times the predetermined frequency band. It is preferably one. In this case, the computer will perform the operation of suppressing the frequency of the first radio wave included in the electric signal before and after the frequency conversion and the strength of signals other than the signal having the frequency N times that frequency.

Since the portable terminal has the above computer (or the computer in which the above program is installed), it functions as the radio wave communication device 5. Therefore, this portable terminal has a signal conversion means for converting the radio wave received by the receiving section into an electric signal, and a frequency conversion means for multiplying the frequency of the output signal from the signal conversion means by N (N is an integer of 2 or more). It has signal amplification means for amplifying the signal output from the frequency conversion means by 40 dB or more, and transmission means for transmitting the signal output from the signal amplification means.

Then, the vehicle communication unit 3 uses the signal having the frequency of the first radio wave or the signal obtained by multiplying the frequency of the first radio wave by N times (N is an integer of 2 or more) as a reference signal, and the first receiving unit The radio communication device is detected using the received second radio wave and the reference signal. In order to realize this function, the vehicle communication unit 3 may have a detection unit 15 for detecting a radio communication device. The detection unit 15 may be implemented by a computer, for example.

FIG. 3 is a flowchart showing an example of a detection process by the detection unit.
The detection unit 15 determines whether the frequency of the second radio wave is N times the frequency of the first radio wave (S101). When the frequency of the first radio wave is changing with time, it may be determined whether or not the frequency of the second radio wave belongs to a frequency band N times the frequency band including the first radio wave.

If the frequency of the second radio wave is not N times the frequency of the first radio wave, the received radio wave is noise (not the second radio wave). In this case, it is determined that there is no obstacle (S102).

When the frequency of the second radio wave is N times the frequency of the first radio wave, the object 41 is detected (S103). In this case, the detection unit 15 reads the time when the first frequency, which is 1/N of the frequency of the second radio wave, is transmitted from the storage unit, and the time when the second radio wave is received and the first frequency are transmitted. A calculation for obtaining the distance between the vehicle 33 (vehicle communication unit 3) and the object 41 (radio wave communication device 5) may be performed from the determined time (S104). In this way, the object is detected.

The present invention can be used, for example, in the automobile industry and portable application industry.

DESCRIPTION OF SYMBOLS 1 Obstacle detection system 3 Vehicle communication unit 5 Radio wave communication device 11 First transmission unit 13 First reception unit 21 Second reception unit 23 Frequency conversion unit 25 Signal amplification unit 27 Second transmission unit 29 Filter 33 Vehicle 41 Object (obstacle)
51 Circulator (directional coupler)

Claims (8)

A vehicle communication unit having a first transmitter that transmits radio waves and a first receiver that receives radio waves;
A second receiver that receives the first radio wave transmitted from the first transmitter, and a frequency that multiplies the frequency of the first radio wave received by the second receiver by N times (N is an integer of 2 or more). A radio wave communication device having a conversion unit, a signal amplification unit that amplifies the signal output from the frequency conversion unit, and a second transmission unit that transmits the signal output from the signal amplification unit as a second radio wave. ，
Including,
The vehicle communication unit uses a signal having a frequency of the first radio wave or a signal obtained by multiplying the frequency of the first radio wave by N times (N is an integer of 2 or more) as a reference signal, and the first reception unit receives the signal. Detecting the radio wave communication device using a second radio wave and the reference signal;
Obstacle detection system. The obstacle detection system according to claim 1,
The signal amplification unit amplifies the signal output from the frequency conversion unit by 40 dB or more. The obstacle detection system according to claim 1,
A system in which the frequency of the first radio wave is one type in a single time. The obstacle detection system according to claim 1,
The first radio wave is a dual-frequency signal, a multi-frequency signal, a frequency sweep signal, or a frequency hopping signal, the system. The obstacle detection system according to claim 1,
The radio communication device further includes a filter that transmits a frequency band of the first radio wave and a frequency band N times the frequency band of the first radio wave. Computer,
Signal converting means for converting the electric wave received by the receiving section into an electric signal,
Frequency conversion means for multiplying the frequency of the output signal from the signal conversion means by N (N is an integer of 2 or more);
Signal amplifying means for amplifying the signal output from the frequency converting means by 40 dB or more,
Transmitting means for transmitting the signal output from the signal amplifying means,
A program that works by doing. The program according to claim 6,
Computer,
A program for causing a signal in a predetermined frequency band of the output signal from the signal converting unit to pass therethrough and also functioning as a frequency transmitting unit for transmitting a signal in a frequency band N times the predetermined frequency band. Signal converting means for converting the electric wave received by the receiving section into an electric signal,
Frequency conversion means for multiplying the frequency of the output signal from the signal conversion means by N (N is an integer of 2 or more);
Signal amplifying means for amplifying the signal output from the frequency converting means by 40 dB or more,
Transmitting means for transmitting the signal output from the signal amplifying means,
Mobile terminal having.

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