JP4670646B2 - Approach notification system - Google Patents

Description

  The present invention provides an approach notification system for notifying the terminal user of the approach of a vehicle by a portable terminal that detects a wireless output from the on-vehicle device mounted on the vehicle, or an on-vehicle device that detects a wireless output from the portable terminal. The present invention relates to an approach notification system for notifying a driver of a vehicle equipped with an in-vehicle device of the approach of the mobile terminal.

As a prior art which tries to make a pedestrian carry a terminal and to secure the safety of the pedestrian using radio waves, there are those disclosed in Patent Documents 1 to 3 below. In particular, Patent Document 2 discloses a conventional alarm system that takes into consideration not only the approach of a pedestrian to the vehicle but also the movement range of the pedestrian and the like. Patent Document 3 proposes that a portable terminal for ensuring the safety of a pedestrian is provided with a power generation device.
JP 2003-173499 A JP-A-2005-202893 JP 2001-299563 A

However, in these conventional portable terminals, communication between terminals regarding a plurality of portable terminals is not performed. Accordingly, since each of these mobile terminals operates independently, for example, as schematically illustrated in FIG. 13, the mobile terminals a, b,. . . When many of them are gathered at one place, information transmission (response transmission) processing from each portable terminal to the in-vehicle device is also performed independently.
For this reason, in the above case, the driver of the vehicle equipped with the in-vehicle device is likely to fall into a situation where more information than necessary is intensively reported at one time, and as a result, the driver makes an appropriate judgment. It is not easy to remove, or the response becomes very troublesome. In such a case, the overhead of the in-vehicle device also increases.

  In addition, in the case of the above, even in the case of the portable terminal side, it is difficult to correctly convey information to be conveyed to the driver of the vehicle equipped with the in-vehicle device, or unnecessary information transmission processing duplicated with other portable terminals is performed. It is easy to fall into the result of executing. Further, if such unnecessary transmission processing is repeated, power is wasted correspondingly, and problems such as difficulty in maintaining a long battery replacement period are likely to occur.

In addition, the detection of an approaching vehicle by a mobile terminal is often difficult to carry out reliably because the terminal carrier himself becomes a radio wave barrier. In addition, the radio wave transmitted from the in-vehicle device gives high directivity to the front of the vehicle using high frequency, but also when the direction of the receiving antenna of the mobile terminal is deviated from that direction, Detection of an approaching vehicle by a portable terminal becomes difficult. Needless to say, the same problem may occur when trying to communicate with the in-vehicle device from the portable terminal side.
Further, it is not always easy to solve these difficulties by improving the transmission / reception performance of a single portable terminal individually, and the portability, power consumption, manufacturing cost, etc. of the terminal are considered. And such improvements are at least not realistic.

  The present invention has been made to solve the above-described problems, and the purpose thereof is to share useful information between mobile terminals located at a short distance from each other by short-range communication between mobile terminals, This is to adjust the distribution of loads that can occur in the system and the timing of operations.

In order to solve the above problems, the following means are effective.
That is, the first means of the present invention is an access notification system for notifying the terminal user of the approach of the vehicle by a mobile terminal that detects a wireless output from an in-vehicle device mounted on the vehicle . An external communication unit that executes communication processing on the order of 100 m with the in-vehicle device and short-range communication processing on the order of several meters between other mobile terminals is lower than the frequency of the radio wave used by the external communication unit A weak wireless node that executes using radio waves of a frequency, and the weak wireless node constitutes a temporary group from a plurality of mobile terminals in one space area capable of short-range communication by weak wireless. And a representative terminal determining means for determining only one representative terminal belonging to the group and representing the group, and the external communication unit of the representative terminal is connected to the approaching vehicle. And, and executes the polarization transmission processing for specified low power radio signals to be transmitted from a mobile terminal belonging to the group on behalf of the group.

  However, the communication by the weak wireless node is assumed to be near field communication within a range of approximately 10 m or less, and usually a range of about 2 m to 3 m may be considered. Therefore, the above short-range communication processing does not relate to communication between the in-vehicle device and the portable terminal, but relates to communication between, for example, portable terminals that are close to each other within a range of about 2 m to 3 m. .

  However, when there is no other mobile terminal in the vicinity of one mobile terminal (in a region where short-range communication is possible), the above-described group may be configured by only the one mobile terminal. In addition, one terminal carrier may walk with a plurality of portable terminals.

Further, a second means of the present invention is the above-mentioned first means, wherein the external communication unit performs the communication process with a specific low-power radio using a radio wave having a frequency of 1 GHz or more. The above-described short-range communication processing is executed by the weak wireless node using weak wireless using a radio wave having a frequency of 600 MHz or less.

The third means of the present invention is to provide representative terminal changing means for sequentially changing the representative terminal in the group in the representative terminal determining means of the first or second means.
In addition, the fourth means of the present invention is to inform other mobile terminals in the group that there is a wireless output from the in-vehicle device in the weak wireless node of any one of the first to third means. The vehicle approach information transmission means for transmitting to the vehicle is provided.

Further, a fifth means of the present invention is the above mentioned first to fourth means, wherein the specified small size from the portable terminal is within a predetermined space area where the safety of the terminal carrier is ensured. It is to provide a transmission processing suppression means for outputting a transmission suppression command for suppressing the transmission processing of the power wireless signal.
However, in the above-mentioned predetermined space area where the safety of the terminal carrier is ensured, for example, it is difficult to cause personal injury such as in a bus or vehicle, indoors, on a sidewalk protected by a guardrail, etc. Say a safe place.
In addition, in the portable terminal that has received the transmission suppression instruction from the transmission processing suppression unit, it is possible to temporarily stop all communication with the in-vehicle device without being limited to the wireless information transmission processing. More desirable.

In the present invention, a fixed station having the same function or device configuration as a mobile terminal may be provided .

In the present invention, a fixed relay station that relays wireless communication between the mobile terminal and the in-vehicle device may be provided .
However, it is more desirable to drive fixed stations and fixed relay stations using natural energy such as solar power generation. However, these stations may be driven by batteries or using commercial power. It may be driven. In addition, it is desirable that these stations be fixed at a position and orientation where communication with an in-vehicle device of an assumed traveling vehicle can be surely performed. For example, a traffic sign installation position such as “stop”, a curve mirror, etc. It is good to arrange it at the installation position.

According to a sixth aspect of the present invention, in the portable terminal that notifies the approach of the vehicle by detecting a wireless output from the in-vehicle device mounted on the vehicle , communication processing of the order of 100 m with the in-vehicle device is performed. A weak wireless node that executes short-distance communication processing on the order of several meters between an external communication unit to be executed and another mobile terminal using a radio wave having a frequency lower than that of the radio wave used by the external communication unit. The weak wireless node includes a group constituting unit that forms a temporary group from a plurality of portable terminals in one space area capable of short-range communication by weak wireless, and a representative that represents the group belonging to the group Representative terminal determining means for determining only one terminal, and the external communication unit of the representative terminal transmits a special signal to be transmitted from the mobile terminal belonging to the group to the approaching vehicle. And executes transmission processing of low-power radio signals in polarization as a representative of the group.

According to a seventh means of the present invention , in the sixth means, the representative terminal determining means has representative terminal changing means for sequentially changing the representative terminal in the group.
In addition, according to an eighth means of the present invention, in the sixth or seventh means, the weak wireless node transmits to the other mobile terminals in the group that there is a wireless output from the in-vehicle device. It has a vehicle approach information transmission means.
By the above means of the present invention, the above-mentioned problem can be effectively or rationally solved.

The effects obtained by the above-described means of the present invention are as follows.
That is, according to the first means of the present invention, it is possible to execute short-range communication between portable terminals, so that useful information can be shared between portable terminals located at a short distance from each other, or a load that may occur in the system It is possible to adjust the distribution and operation timing, and to perform optimization control.

Consists temporary group from a plurality of mobile terminals in the near distance communication above one spatial area as possible, only one representative terminal representative of the group belong to the group, the vehicle approaching Since the transmission processing of the wireless information to be transmitted is executed unevenly as a representative of the group, each mobile terminal is prevented from responding independently to the in-vehicle device. For this reason, according to the first means of the present invention, it is possible to prevent simultaneous responses to the in-vehicle device from each of the mobile terminals gathered in one place, and at the same time, easily suppress the waste of power in the mobile terminal. it can.
Therefore, according to the first means of the present invention, the driver does not have to respond to an unnecessary simultaneous response from each mobile terminal, and the troublesomeness of the response is effectively reduced, and the power of the mobile terminal is reduced. Is effectively suppressed. Moreover, since communication between portable terminals is performed by weak wireless, a high power saving effect can be obtained also in that respect.

In addition, according to the third means of the present invention, in the above communication processing and short-range communication processing, frequency bands can be distributed in accordance with the current radio law in Japan, and frequency bands suitable for each communication processing can be implemented. Can be assigned to each communication process. For example, in the above short-range communication, it is desirable to use radio waves in a frequency band that facilitates omnidirectional communication. Further, in communication between the in-vehicle device and the portable terminal, a frequency band that can easily realize communication at a distance of about 100 m with as little power consumption as possible should be selected.
That is, according to the second means of the present invention, it is possible to rationally allocate these frequency bands.

Further, according to the third means of the present invention, since the power consumption load is not concentrated on a specific portable terminal in the group, the above-described power waste suppression effect which is an advantage of configuring the group is configured. Can be shared equally among all mobile terminals.

In addition, according to the fourth means of the present invention, even when there is only one portable terminal in the group that can detect the approach of the vehicle on which the in-vehicle device is mounted, the wireless communication from the in-vehicle device is performed. Since the output is transmitted to other mobile terminals in the group, all the mobile terminals constituting the group can know the approach of the vehicle.

Further, according to the fifth means of the present invention, since a situation in which unnecessary information is transmitted from the portable terminal in the predetermined space area to the in-vehicle device is avoided, Only necessary and sufficient response information is transmitted only from portable terminals in other areas where the possibility of human injury is relatively high. For this reason, according to the fifth means of the present invention, the driver of the vehicle equipped with the in-vehicle device does not receive unnecessary information, makes it easy to make an appropriate decision, and more than necessary to deal with the reception result. Is effectively eliminated.

Further, by fixing the fixed station to the position and orientation communication with vehicle devices running vehicle to be virtual constant it can be reliably performed, the terminal wearer entering the weak radio communication feasible range of the base station It is possible to configure the above group with the fixed station. For this reason, for example to be terminal mobile who are bad alley of view, since it is possible to tell with certainty the approach of the vehicle from the above fixed station, human trafficking is based on such a sudden jump out of the pedestrian from such alley accident The effect of preventing such problems can be further increased. Therefore, it is desirable to arrange these stations at, for example, “stop” traffic signs, installation positions of curve mirrors, and the like.

Furthermore, it relays the transmission information from the car mounting device to the portable terminal, since it is possible by the fixed relay station, a mobile terminal that can detect the approach of a vehicle in which the vehicle-mounted device mounted Even when there is no unit in the group, it can be transmitted from the fixed relay station to at least one mobile terminal in the group that there is a wireless output from the in-vehicle device. For this reason, one or all of the mobile terminals constituting the group can know the approach of the vehicle.
Further, if the fixed relay station is used in the reverse direction, it is possible to reliably perform a response to the in-vehicle device from the mobile terminal side in that case.

  The power source of the portable terminal may be arbitrary, and for example, a generator using natural energy may be used in addition to the battery. As such a generator, for example, a generator that performs solar power generation or a generator that converts kinetic energy of a pedestrian into electric energy can be considered.

Moreover, it is good to use specific low power radio | wireless in the communication from the vehicle-mounted apparatus side with respect to a portable terminal. This specific low-power radio is, for example, a high frequency of 1 GHz or more, and it is easy to give directivity to these high frequencies. Therefore, if such a radio is used, the mobile phone is about 50 to 100 m ahead of the vehicle. Radio waves can be reliably irradiated from the in-vehicle device to the terminal.
In addition, if the receiving antenna of the in-vehicle device is also used for high frequency reception and directivity thereof is directed forward, the source of the received signal can be easily limited to the front of the vehicle by the directivity setting, whereby the system Can be effectively used to prevent accidents, and unnecessary reception from the rear or side of the vehicle can be eliminated, leading to a reduction in the number of receptions more than necessary.

  On the other hand, in communication between portable terminals, it is desirable that there is no directivity for transmission and reception of radio waves, so it is desirable to use a low frequency of about 300 MHz, for example. Further, for example, if the group configuration falls within a radius of about 2 m to 3 m, for example, from a distant vehicle of about 50 m to 100 m, the one group composed of a plurality of mobile terminals is regarded as one terminal carrier. be able to. Therefore, in this respect, it can be said that it is reasonable to provide a portable terminal with a weak wireless node using a low frequency. In addition, it is obviously advantageous to realize communication between portable terminals by weak wireless from the viewpoint of power consumption.

Hereinafter, the present invention will be described based on specific examples.
However, the embodiments of the present invention are not limited to the following examples.

FIG. 1 is a system configuration diagram of an approach notification system according to the first embodiment. The wireless A in the figure is used for communication between the mobile terminal 100 and the in-vehicle device 900 mounted on the vehicle, and is implemented by a specific low power wireless as in the conventional case. On the other hand, the wireless B in the figure is a wireless that realizes the short-range communication by the above-described weak wireless. The wireless B can be used to realize communication between the mobile terminals (100, 100) or the forced sleep terminal 800 ( The sleep signal σ output from the transmission processing suppression means) can be received. The sleep signal σ is a signal for temporarily stopping the operation of each mobile terminal 100.
Therefore, the antenna AN1 in the figure is configured to correspond to the wireless A, and the antenna AN2 is configured to correspond to the wireless B.

  The main part of the portable terminal 100 includes an external communication unit 110 that executes the process related to the wireless A and a weak wireless node 120 that executes the process related to the wireless B. The signal transmitted from the external communication unit 110 to the weak wireless node 120 includes, for example, the reception intensity ρ when there is reception from the in-vehicle device 900. On the other hand, as a signal transmitted from the weak wireless node 120 to the external communication unit 110, for example, a representative bit LD indicating whether or not the mobile terminal 100 is a representative of the group, a reception signal SLC of the sleep signal σ, and the like. is there. The table structure of the storage area of main control variables to be shared among the control units such as the reception strength ρ, the representative bit LD, and the number of receptions SLC, and the update method thereof will be described in detail later.

  FIG. 2A shows a control block diagram of the external communication unit 110 described above. The filter F includes a matching circuit and a band pass filter, and selectively transmits only a frequency band of a predetermined RF high frequency signal to be transmitted / received via the antenna AN1. The switch SW1 selectively connects one of the reception processing unit 111 and the transmission processing unit 112 to the filter F, and this selection operation is controlled by the communication control unit 111j. That is, the switch SW1 dynamically switches a circuit to be connected to the antenna AN1 between the reception processing unit 111 (the envelope detection unit 111a) and the transmission processing unit 112 (the oscillator 112b).

  In the reception processing unit 111 of the external communication unit 110, the envelope detection unit 111a, the amplifier 111b, the binarization circuit 111c, and the control block of the shift register 111d are connected in series in this order from the SW1 side. Yes. In particular, in a serial connection composed of the circuits 111a, 111b, and 111c, a known so-called wake-up circuit or the like can be used as a kind of receiving means. For example, Japanese Patent Application Laid-Open No. 2004-194301 is applied to the present invention. A specific configuration example such as a possible wakeup circuit is disclosed.

  The transmission processing unit 112 is configured by serial connection of each control block of the oscillator 112b and the waveform shaping circuit 112a. A detailed configuration example of the transmission processing unit 112 will be described later with reference to FIG. Illustratively.

Each circuit of the reception processing unit 111 and the transmission processing unit 112 is supplied with power from a DC power source E formed of a coin battery. The reception processing unit 111 always needs about 10 μA of power supply, but the transmission processing unit 112 only needs to supply about 300 μA to 400 μA as an average value during the transmission period only when transmission processing is executed. Is enough.
In addition, the DC power source E (small current power source) described above includes a power source configured by combining a generator (for example, a wristwatch generator) using natural energy and a secondary battery (for example, a capacitor). It may be used.

  Further, a switch SW2 is provided between the shift register 111d and the waveform shaping circuit 112a. By this opening / closing operation, the bit string signal (control pattern data) temporarily stored in the shift register 111d is transmitted to the transmission processing unit 112. Are allowed as required. Hereinafter, the transmission permission / inhibition action will be described.

  Although it is finally determined by the communication control unit 111j whether or not the transmission of the bit string signal (control pattern data) to the transmission processing unit 112 is necessary, the determination processing is the reception of FIG. The determination may be performed based on the determination results (a, b, and c in the figure) of the following three units included in the processing unit 111, the representative bit LD, the number of reception times SLC, and the like. Such a control procedure will be specifically illustrated later with reference to FIG.

(1) Approach determination means (111e-g)
The approach determination means of the first embodiment provided in the external communication unit 110 includes an envelope detection unit 111e, a differential operation unit 111f, and a determination processing unit 111g. The envelope detector 111e is means for detecting an envelope signal output to a point B between the stages of the amplifier 111b and the binarization circuit 111c as a signal having a longer period. The signal detected by the detection unit 111a is further converted into an envelope signal having a longer wavelength.
The differential calculation unit 111f obtains the slope (time differential value) of the envelope signal output from the envelope detection unit 111e.
The determination processing unit 111g at the next stage outputs a = 1 to the communication control unit 111j if the slope is larger than a predetermined constant (≧ 0), and outputs a = 0 otherwise. Based on this determination, it is determined whether or not the mobile object having the in-vehicle device 900 is approaching the mobile terminal 100. Of course, the above determination result showing a = 1 means that the moving body is approaching.

(2) Transmitting station determining means (transmitting station determining unit 111h)
Based on the envelope signal binarized by the binarization circuit 111c, the transmitting station discriminating unit 111h obtains the period of the envelope signal, and when this period has an assumed value, the communication control unit B = 1 is output to 111j, otherwise b = 0 is output. By this determination, it is determined whether or not the application adopted by the transmission source station (that is, the in-vehicle device 900) conforms to a predetermined communication protocol. At this time, if the determination result is b = 0, it is highly possible that the incoming signal received by the antenna AN1 is noise.

(3) Traffic frequency determination means (traffic frequency determination unit 111i)
When there are a plurality of mobile bodies (vehicle-mounted devices 900) around the user of the mobile terminal 100, the signals transmitted from the mobile bodies are overlapped. Therefore, at the stage of point B in FIG. The envelope hardly attenuates for a certain time or more, or a high amplitude often appears partly. For example, when an envelope signal indicating received power of a certain value or more with almost no attenuation is digitized by the binarization circuit 111c, the data of the digital signal once stored in the shift register 111d is, for example, '0011111111111100' Obtained as a bit string.

  At this time, the traffic frequency determination unit 111i refers to the bit string data on the shift register 111d binarized as described above, and the number of bits whose value is 1 with respect to the total number of bits within a predetermined sampling period. When the ratio reaches, for example, 70% or more, or when such a state is continuously detected, c = 0 is output to the communication control unit 111j. In other cases, c = 1 is output. That is, it is possible to determine the degree of congestion of the mobile object to be detected from the on-bit occupation ratio in the pulse train, and as a result, the communication control unit described above only when the traffic volume around the user of the mobile terminal 100 is relatively small. It is possible to output c = 1 for 111j. It has been found that there is a tendency that personal accidents are less likely to occur when the traffic volume is relatively high.

Since the communication control unit 111j of the reception processing unit 111 can use the above three determination results a, b, and c, in any of the following (1) to (3), the in-vehicle device 900 The response transmission from the portable terminal 100 can be stopped. That is, if a × b × c = 0, the switch sw2 may be left open.
(1) The mobile body (on-vehicle device 900) that is the signal source is not in an approaching state.
(2) The received signal does not comply with the assumed communication protocol. That is, radio waves or other noises sent from unexpected applications were received.
(3) The traffic frequency of the mobile body (on-vehicle apparatus 900) around the user is relatively high.
Moreover, if such a suppression operation is introduced, the power consumption of the mobile terminal 100 can be more effectively saved.

  Moreover, you may further add alarm means, such as a vibrator and LED, to the portable terminal 100. FIG. In the drive mechanism that drives such warning means for the terminal carrier, if the above-described deterrent action based on the determination results a, b, c is used, the traffic volume of the mobile body is particularly high. Problems such as alarm output from the alarm means being continued more than necessary can be avoided in advance.

  FIG. 2B shows a circuit diagram of the waveform shaping circuit 112a included in the transmission processing unit 112. The waveform shaping circuit 112a is used recently for pulse power supplies, DC-DC converters, and the like, but these waveform shaping circuits have been used exclusively for the purpose of stabilizing power feeding. However, in the transmission processing unit 112 of the first embodiment, the load of the oscillator 112b is operated periodically (intermittently) using the temporary current increase effect based on the waveform shaping action of the waveform shaping circuit 112a. There is also a feature.

The waveform shaping circuit 112a is provided with capacitors C1 and C2. When the two switches SWb are opened (off) and the two switches SWa are closed (turned on), the capacitor C1 , C2 are connected in parallel to each other, and these capacitors C1, C2 are both charged by the DC power source E via the resistor R.
When the two switches SWa are opened (off) and the two switches SWb are closed (turned on), the capacitors C1 and C2 are connected in series with each other. A potential that is twice as large as the potential generated individually between the terminals of the capacitors C1 and C2 can be generated between both terminals of the capacitor C3. By executing the on / off control of these switches SWa, b using the bit string once held in the shift register 111d, the load of the oscillator 112b can be operated periodically (intermittently). .

That is, since the low-pass filter LPF1 including the inductor L and the capacitor C3 is provided at the output portion of the waveform shaping circuit 112a, the charges stored in the capacitors C1 and C2 are discharged through the low-pass filter LPF1 during this discharge. The power is supplied to the oscillator 112b. Even if the power supply time for the load (oscillator 112b) at this time is, for example, on the order of about 0.1 millisecond, if the capacitance value or resistance value of each capacitor of the waveform shaping circuit 112a is appropriately set, the oscillator 112b is sufficient. It can be operated intermittently with output.
An oscillator used for the oscillator 112b is suitable, for example, a SAW oscillator that rises quickly and whose oscillation frequency does not depend on the power supply voltage (V _CC ).

FIG. 3 illustrates a flowchart of a control procedure 200 to be executed by the communication control unit 111j in FIG. Such digital processing may be realized by hardware, or may be realized by computer software such as a timer interrupt routine.
First, in the first step 210 of this control procedure 200, a predetermined length of time is waited (processing is stopped). This waiting (stopping time) may be realized using a timer. This waiting length can be arbitrarily set as long as the response performance of the apparatus is not hindered. Considering the power consumption of the apparatus, it is desirable to wait as long as possible within the range.

  Next, in step 220, the logical product, that is, a × b × c is obtained based on the determination results a, b, and c. If the operation result is 1, go to step 230; The process moves to step 210.

Next, in step 230, the value of the reception strength ρ (height of the envelope of the carrier) detected by the envelope detector 111e is a predetermined storage area accessible from the weak radio node 120 in FIG. 1 (shared in FIG. 7). It is output on the save area T02) on the control table CT.
Next, in step 240, the value of the above-mentioned reception number SLC is checked. If the value is 0, the process proceeds to step 245, and if not, the process proceeds to step 210.

Next, in step 245, the value of the representative bit LD is checked. If the value is 1 (on state), the process proceeds to step 250. If not, the process proceeds to step 210.
Next, in step 250, the switch SW1 in FIG. 2A is connected to the transmission processing unit 112 side.
Next, in step 260, the switch SW2 in FIG. 2-A is closed (ie, turned on).

Next, in step 270, the process waits for a predetermined length of time (stops processing). This waiting (stopping time) may be realized using a timer. This waiting length is long enough to execute the transmission operation performed using the bit string once held in the shift register 111d, that is, the transmission operation of the transmission processing unit 112. To.
Next, in step 280, the switch SW1 in FIG. 2A is connected to the reception processing unit 111 side.
Next, in step 290, the switch SW2 in FIG. 2-A is opened (that is, in the off state).

  Through the switching control (control procedure 200 in FIG. 3) of the communication control unit 111j as described above, the transmission processing unit 112 receives a predetermined code (bit string) held in the shift register 111d as a reply response to the in-vehicle device 900 that is the transmission source. Signal) can be transmitted from the antenna AN1 via the filter F.

  That is, based on the operations of the reception processing unit 111 and the transmission processing unit 112 described above, the external communication unit 110 of the mobile terminal 100 can perform a reply response to the in-vehicle device 900 that is the transmission source. Are allowed / suppressed based on the action of step 245. That is, since this reply response is executed by one representative terminal representing the group in an unequivocal manner, according to these configurations, when the group is composed of a plurality of portable terminals, this representative terminal Simultaneous response from all nearby mobile terminals is avoided. Also, the sleep signal σ (that is, the transmission suppression command of the present invention) periodically transmitted from the forced sleep terminal 800 of FIG. 1 (that is, the transmission processing suppression unit of the present invention) is received by the antenna AN2 of FIG. If so, the reply response is effectively suppressed by the action of step 240 in FIG. 3 and the actions of steps 310 and 320 in FIG.

Hereinafter, the operation of the mobile terminal 100 related to the wireless B will be specifically described. This communication operation is realized by the weak wireless node 120 in FIG.
FIG. 4 shows a group configuration example of a plurality of portable terminals 100 at intersections of general roads. Each of the pedestrians a, b, c, and d in FIG. 4 carries one portable terminal 100. However, even if a single pedestrian with multiple mobile terminals is in the group, there is no particular difference in level. Here, a state is shown in which a mobile terminal 100 possessed by a pedestrian d is newly added to a group of three mobile terminals 100 possessed by each of the pedestrians a, b, and c. .

FIG. 5 illustrates how the group representatives are sequentially changed at this time. The hatched portion in the figure indicates a period in which each mobile terminal is a representative terminal, and time t ₁ indicates the time when the mobile terminal 100 held by the pedestrian d can join the above group. ing.
The downward arrow in the figure indicates the representative declaration time of each mobile terminal 100, and this representative declaration process is executed using the wireless B. The mobile terminal 100 that has declared itself that the mobile terminal 100 is a representative of the group by transmitting a predetermined representative declaration signal using the wireless B until the reception of a representative declaration signal from the other mobile terminal 100 Hold the right to represent the group. That is, the representative terminal of the group (: representative bit LD = on).

  Further, as shown in FIG. 5, by receiving a representative declaration signal from another portable terminal 100, the portable terminal 100 (: representative bit LD = off) that is no longer the representative terminal receives a timer interrupt for the fifth time thereafter. At this time, the representative is declared by transmitting a predetermined representative declaration signal using the wireless B again. The processing of this timer interruption (timer interruption routine 1 in FIG. 8) will be described in detail later.

A short vertical line on the horizontal bar graph in FIG. 5 indicates the timing of the timer interruption. This timer interruption may be generated in each portable terminal 100, for example, about every 1 second. In addition, the timer interruption is performed so that the timing of occurrence does not overlap between the portable terminals 100. As a method of setting so that the timing at which the timer interrupt occurs does not overlap, for example, it may be set using the timing (time) when the user turns on the power switch, or may be shifted from each other using an appropriate random number. May be.
If these controls are followed, the representative terminals of the group can be sequentially changed to equality without providing any upper and lower layers between the mobile terminals 100.

Hereinafter, a control processing procedure for realizing such control will be described in detail.
FIG. 6 shows a flowchart of the radio B reception interrupt routine 300 executed by the weak radio node 120. In this reception interrupt routine 300, the following variables are used. These variables are stored on any storage area in the control variable table CT configured from the control variable storage areas T01 to T08 shown in FIG.
(Variable symbol)
SLC: sleep signal reception count GPC: intra-group communication reception count KC: alarm transfer signal reception count LD: representative bit I: representative declaration processing wait time counter

  The reception interrupt routine 300 is called and executed every time the weak wireless node 120 receives a signal related to the wireless B. In the first step 310, it is determined whether or not the received signal is the sleep signal σ of FIG. 1. If it is the sleep signal σ, the process proceeds to step 320; otherwise, the process proceeds to step 330. Move. In step 320, the value of the counter SLC that counts the number of times the sleep signal is received is incremented by 1, and then control is returned to the caller.

  If the received signal is not the sleep signal σ, the signal is a signal transmitted from the other portable terminal 100. Therefore, in step 330, the value of the counter GPC that counts the number of intra-group communication receptions is incremented by one. .

  Next, in step 340, it is determined whether or not the signal received by the radio B this time is a predetermined joint signal. This joint signal is a signal for mutual communication between portable terminals for forming the above-described group, and is transmitted from each portable terminal 100 at the timing of each timer interruption indicated by a short vertical line in FIG. is there. However, as will be described in detail later with reference to FIG. 8, when the above-described representative declaration process is executed, the transmission of the joint signal can be omitted. In step 340, if the signal received by the radio B this time is a predetermined joint signal, the control is returned to the caller as it is. If not, the next step 350 is executed.

  In step 350, it is determined whether or not the signal received by the wireless B this time is a predetermined alarm transfer signal. This alarm transfer signal is for transferring vehicle approach information from the mobile terminal 100 that knows the approach of the vehicle-mounted device 900 to another mobile terminal 100. The condition for transmitting the alarm transfer signal will be described in detail later with reference to FIG. Here, if the signal received by the wireless B this time is a predetermined alarm transfer signal, the next step 360 is executed, and if not, the process proceeds to step 370.

In step 360, the alarm transfer signal reception count KC is counted, and thereafter control is returned to the caller.
In step 370, it is determined whether or not the signal received by the wireless B this time is a predetermined representative declaration signal. At this time, if the received signal is not a predetermined representative declaration signal, the control is returned to the caller as it is. If the received signal is a predetermined representative declaration signal, step 380 is executed.

In step 380, the representative bit LD is determined. If LD = on, the representative bit LD is turned off in step 385, and the wait time counter I of the representative declaration process is reset to 0 in the next step 390. Return control to the caller. If the determination result at step 380 is LD = off, then control is returned to the caller without doing anything.
The above variable update processing is referred to or updated by each timer interrupt routine shown in FIGS. In other words, these variable update processes are intended to correctly establish the logic of each timer interrupt routine shown in FIGS.

A control procedure 400 shown in FIG. 8 shows the processing contents of the timer interrupt routine 1 executed by the weak wireless node 120. This timer interrupt routine 1 is periodically executed at a cycle of 1 second here. This timer interrupt routine 1 is for accurately managing the execution times (execution timings) of the following processing 1 to processing 5.
(Processing 1) Reset sleep signal reception count (SLC counter) (step 426)
(Process 2) Output of joint signal (step 480)
(Process 3) Output of representative declaration signal (step 476)
(Process 4) Setting of representative bit LD (step 474)
(Processing 5) Resetting the number of intra-group communication reception (GPC counter) (step 456)

  For these processes, the previously mentioned control variable table CT (FIG. 7) is used. For example, in step 416, the current sleep signal reception count SLC is saved in the array SL (k) defined in the control variable storage area T04 in FIG. If the sleep signal σ has never been received during this period, the above process 1 (step 426) is executed.

  The sleep signal reception count SLC on the save area T03 in FIG. 7 referred to in step 240 of the control procedure 200 in FIG. 3 is based on the control procedure 300 in FIG. 6 and the control procedure 400 in FIG. It has been updated as described above.

In step 428, all the values of the array SL (k) on the save area T04 in FIG.
The waiting time counter I for the representative declaration process updated in step 430 is incremented by 1 each time the timer interrupt routine 1 is called when the portable terminal 100 is not in the sleep state. Therefore, if this counter I is used, as can be understood from the operation of steps 370 to 390 in FIG. 6 and the time chart in FIG. Can do.

  The processing from step 440 to step 458 is very similar to the processing from step 410 to step 428, and here, substantially the same processing is executed for the intra-group communication reception count (GPC). Therefore, if the wireless B from the other portable terminal 100 has not been received in the past 3 seconds by the action of step 454, step 456 (processing 5) and step 458 are executed. Otherwise, step 470 is executed. This step 470 is based on the operation of the waiting time counter I to determine whether or not about 5 seconds have passed since the time when the representative right was once lost.

Accordingly, when about 5 seconds have passed since the time when the representative right was lost, or when it is determined that the group member is only the own mobile terminal 100 (that is, when step 456 is executed). ), Step 474 (Process 4) and Step 476 (Process 3) are executed. Otherwise, step 480 (Process 2) is executed.
The joint signal output in step 480 and the representative declaration signal output in step 476 are both transmitted using the radio B, but the contents of the signals are slightly different.

With the above processing, the following effects can be obtained.
(Effect 1) A group of mobile terminals 100 can be easily configured by ad hoc communication using the wireless B.
(Effect 2) Since the representative terminal of the group can be easily determined and the representative terminal can be changed sequentially and equally, the processing load is not biased to the specific portable terminal 100.
(Effect 3) In the environment where the sleep signal σ is periodically transmitted by the forced sleep terminal 800 of FIG. 1 at a period of about 3 seconds, for example, the above-described simultaneous response from all the mobile terminals can be avoided. The operation of the unit 110 is effectively suppressed. In addition, waste of power within the group can be sufficiently suppressed.

  FIG. 9 illustrates an example of alarm transfer within a group of mobile terminals 100. There are four pedestrians such as a pedestrian a and a pedestrian b on the side road in FIG. 9, and each pedestrian carries one portable terminal 100. Further, these four mobile terminals 100 constitute one group. It is assumed that only the mobile terminal 100 that the pedestrian a has now can receive the wireless A transmitted from the in-vehicle device 900 mounted on the vehicle. At this time, notifying other three parties such as the pedestrian b of the approach of the vehicle is considered to be meaningful for the safety of the three parties.

In such a case, the communication process for communicating the approach of the vehicle from the mobile terminal 100 of the pedestrian a to the other three mobile terminals 100 in the group is called alarm transfer. This alarm transfer is executed as one step (step 580) of the following timer interrupt routine 2 using the wireless B.
FIG. 10 shows a flowchart of the timer interrupt routine 2 (control procedure 500) executed by the weak wireless node 120 of each mobile terminal 100. This flowchart (control procedure 500) may be considered as a summary of the execution conditions for executing the above-described alarm transfer. The timer interrupt routine 2 is a control program that is called and executed periodically, for example, every 0.1 second.

The alarm transfer (step 580) is performed when the mobile terminal 100 is in a sleep state (when SLC> 0) or when the mobile terminal 100 does not constitute a group of a plurality of terminals (: GPC). When = 0, there is no need to execute. Steps 510 and 520 determine the necessity of this execution.
In step 530, it is determined whether or not the reception strength ρ is greater than a predetermined threshold ρ0. The threshold value ρ0 is used to determine whether or not the vehicle is approaching. The reception strength ρ is stored in the save area T02 of FIG. 7 by the above-described step 230 executed by the communication control unit 111j. It is a numerical value.

If there is a vehicle approaching that the pedestrian should be aware of, the process proceeds to step 550, and if not, the process proceeds to step 540. Step 550 waits for a time interval ΔT determined using a random number. As the value of the time interval ΔT, a value between 0.0 seconds and 0.1 seconds is randomly selected using a random number. However, this step 550 is not necessary if the timing at which the timer interrupt routine 2 is called is appropriately distributed without overlapping between the mobile terminals 100 during the calling period of 0.1 seconds.
In the next step 555, the number M of links in the alarm transfer process is cleared to zero. This link number M records the number of times the alarm is transferred between mobile terminals. Therefore, this information (number of links M) is included in the alarm transfer signal to which the alarm is transferred. The reason why the value of M is cleared to 0 in step 555 is because the approach of the vehicle is detected by itself in step 530. That is, the alarm transmission source that has detected the approach of the vehicle itself sets M = 0 initially.

  In step 560, the alarm transfer signal reception count KC counted in step 360 of FIG. 6 is determined. If the value of the counter KC is positive, the process proceeds to step 590; otherwise, the process proceeds to step 570. The reason why the alarm transfer (step 580) is not executed when KC> 0 is that other mobile terminals 100 in the group have already detected the approach of the vehicle and have already completed the alarm transfer processing operation. Because it is. In other words, such operations of other terminals can be monitored by steps 350 and 360 in FIG.

On the other hand, in step 540, the process proceeds to step 570 only when KC = 1, and in other cases, the process proceeds to step 590. Here, the reason that the execution of the alarm transfer process is limited to the case of KC = 1 is to prevent duplication and flooding of alarm transfers within the group, as in step 560.
In step 570, the number of links M is increased by one. In step 575, the upper limit value MM of the number of links M is compared with the number of links M. If M ≦ MM, the process proceeds to step 580, and if not, the process proceeds to step 590. The upper limit MM is suitably about 1 to 3. If this value is too large, an unnecessary alarm transfer may be transmitted to the portable terminal 100 carried by an irrelevant pedestrian who is sufficiently far away from the detected approaching vehicle.

In step 580, the wireless B is used to transfer a warning to the other mobile terminals 100 in the group that the vehicle should be approached.
In step 590, the alarm transfer signal reception count KC is cleared to zero. In step 595, the reception strength ρ is cleared to zero. These proper initialization processes also prevent duplication and flooding of alarm transfers within the group.

Note that the case of passing through the control path from step 560 to step 570 corresponds to the case where the alarm transfer illustrated in FIG. 9 is performed.
Further, 2 in the case where only the mobile terminal 100 carried by the pedestrian a in FIG. 4 detects the approach of the vehicle by itself, and then the alarm transfer is sequentially performed in the order of the pedestrian a → the pedestrian b → the pedestrian d. This corresponds to the case where the second alarm transfer (pedestrian b → pedestrian d) passes through the control path from step 540 to step 570. In this case, the alarm transfer cannot be transmitted directly from the mobile terminal 100 of the pedestrian a to the mobile terminal 100 of the pedestrian d because of the group configuration in the figure, but the alarm transfer is not performed by the mobile terminal 100 of the pedestrian b. Information transfer is relayed.

FIG. 11 is a plan view of a general road illustrating the operation of the fixed station Q of the present invention. This fixed station can be configured in the same manner as the portable terminal 100 described above. However, the power source does not necessarily need to be downsized or portable.
If such a fixed station Q is installed in the vicinity of the entrance to the side road, for example, the fixed station Q can have the same alarm transfer function as the portable terminal 100 carried by the pedestrian a in FIG. It becomes possible. If such a fixed station Q having a function equivalent to that of the mobile terminal 100 is arranged at a road corner or the like, a group of the mobile terminals 100 is configured to include such a fixed station Q in the vicinity thereof. Will be. For this reason, the owner of the portable terminal that has approached the roadway where such a fixed station is deployed can detect the approach of the vehicle more reliably and earlier.
Further, according to such a configuration, the directivity of the antenna of the fixed station Q can also be set arbitrarily, so that the detection of the in-vehicle device 900 in the fixed station Q, the reply response from the fixed station Q to the in-vehicle device 900, etc. It becomes possible to carry out more reliably.

[Other variations]
The embodiment of the present invention is not limited to the above-described embodiment, and other modifications as exemplified below may be made. Even with such modifications and applications, the effects of the present invention can be obtained based on the functions of the present invention.

(Modification 1)
For example, the fixed station Q of FIG. 11 may be changed to the fixed relay station of claim 6 of the present invention. In this case, the fixed relay station Q can notify the portable terminal 100 carried by the pedestrian a using the wireless A and the approach of the vehicle to the portable terminal 100 carried by the pedestrian a using the wireless B. An approach can also be notified.
Also, the portable terminal 100 carried by the pedestrian a can notify the fixed relay station Q of the presence of the mobile terminal 100 using the wireless A or the wireless B.

In other words, the fixed relay station Q can be implemented as the mobile terminal 100 or can be implemented as the in-vehicle device 900.
And by installing such a fixed relay station Q near the entrance of a side road, for example, it is possible to effectively eliminate the blind spot of radio waves between vehicle pedestrians. The configuration of the fixed relay station Q may be the same as that of the mobile terminal 100, for example. However, it is desirable from the viewpoint of environmental hygiene to use natural energy such as solar power generation for the power source.

(Modification 2)
In FIG. 12, the control procedure 201 of this modification 2 which is another Example of this invention is illustrated. This control procedure 201 is an improvement of the above-described control procedure 200. This control procedure 201 is the same as the above-described control procedure 201 except that step 245 in FIG. 3 is replaced with steps 243 and 246 in FIG. Same as procedure 200. In this step 243, if the value of the above-mentioned alarm transfer signal reception count KC is 0, the process proceeds to step 246, and if not, the process proceeds to step 210.

  Then, in the next step 246, the weak wireless node 120 in FIG. 1 is instructed to execute the alarm transfer process similar to that executed in step 580 (FIG. 10). In addition to replying to the in-vehicle device 900 through a series of operations of Steps 250, 260, and 270, the reason for transferring a warning about the approach of the vehicle to the peripheral mobile terminals 100 based on Step 246 is as follows. This is because high-frequency signal transmission by the external communication unit 110 is accompanied by directivity. That is, if the wireless B (short-range communication) is simultaneously used here, a desired alarm transfer can be transmitted more reliably in all directions.

  Note that the waiting time in step 210 is set to a value different from each other for each mobile terminal 100. The appropriate range of this value may be the same as step 210 in the first embodiment. As a method of changing the waiting time for each terminal, for example, there is an implementation method that uses a random number in milliseconds or uses the power-on time of each terminal carrier.

  By following such a control procedure, a phenomenon in which a large number of similar reply responses are duplicated from the plurality of portable terminals 100 located near each other to the in-vehicle device 900 by the action of step 243 and step 210 in advance. Can be prevented. In addition, vehicle approach information can be shared among a plurality of mobile terminals 100 located near each other at the same time by the action of step 246. Further, the waiting time for the above random setting may be measured from the reception time of a predetermined signal from the in-vehicle device 900 as a reference. Alternatively, a setting may be made such that the waiting completion time in step 210 is random.

  According to such a control procedure, steps 330 and 340 and steps 370 to 390 of the control procedure 300 of FIG. 6 are omitted, or steps 430 to 480 of the control procedure 400 of FIG. 8 are omitted. Therefore, an effect of reducing the number of development steps due to rationalization of processing in the mobile terminal 100 can be obtained, and at the same time, a further power saving effect in the mobile terminal 100 can be obtained.

In addition, it is desirable to take measures such as changing the waiting time periodically so that the load is not easily concentrated on one specific mobile terminal 100. For example, if this waiting time is fixed as a parameter unique to each mobile terminal 100, a mobile terminal that is likely to return a response to the in-vehicle device 900 and a mobile terminal that is not likely to occur naturally may occur naturally. It is not desirable to have a portable terminal that is easily entrusted with a power saving effect and a portable terminal that does not.
As the above treatment, for example, the power-on time (time when the switch is turned on) in the mobile terminal 100 may be used. Since such a numerical value is random and the setting is changed every time it is used, it is possible to effectively prevent the load from being concentrated on a specific mobile terminal 100 by using such a numerical value. .

(Modification 3)
Further, the number of terminals constituting the group of portable terminals 100 may be returned to the in-vehicle device 900 as a response. As a result, the driver can foresee the general state of the pedestrian group from a distance early.
Alternatively, a received signal (eg, application code or the like) such as an in-vehicle device ID received by the receiving unit 113 may be returned as a response to the in-vehicle device 900 as it is. In this case, the in-vehicle device 900 may be able to effectively perform communication noise elimination processing.

  Also, the receiving method of the receiving unit 113 may be arbitrary, and any of a wide variety of receiving methods from those that detect a carrier envelope at a relatively low frequency to those that realize advanced demodulation methods. Can be selected and applied.

In particular, in the case where the receiving unit 113 has a simple structure with low power consumption, the activation signal output circuit 112 in FIG. 2 is not necessarily provided. As the configuration of the power saving mechanism, an appropriate one may be adopted in light of the standard value of the amount of power required per hour of the portable terminal calculated based on the standard power consumption of each circuit.
The configuration of the power supply means used in the power supply unit E1 in FIG. 2 may be arbitrary. For example, a booster circuit or natural energy may be used to save power consumption.

  The arithmetic processing performance of the CPU to be used may be determined according to the required processing performance. For example, the weak wireless node 120 does not require a processing capability as fast as the external communication unit 110 that should correspond directly to the in-vehicle device 900. Therefore, the processor used for the weak wireless node 120 is more than the processor used for the external communication unit 110. Can also be made up of cheaper and cheaper ones. For example, in this way, by suppressing the processing performance of the processor used for the weak wireless node 120 to be relatively low, the power consumption of the entire mobile terminal 100 can be further reduced.

  Needless to say, the weak wireless node 120 handling the wireless B is easier to configure in the low power consumption type than the external communication unit 110 handling the wireless A. Therefore, according to the present invention that suppresses the useless transmission operation on the external communication unit 110 side based on the operation of the weak wireless node 120, the power consumption suppressing effect can be obtained very effectively.

The present invention is particularly effective in constructing an accident prevention system that is effective when a person who is likely to be a victim of a personal injury such as an elderly person, a child, or a disabled person travels on a general road. In addition, the terminal may be installed in a bicycle, a wheelchair, a stroller, a guide dog, a pet, or the like.
Further, the transmission processing suppression means (for example, forced sleep terminal 800) of the present invention may be incorporated as a part of the in-vehicle device 100 described above. In this case, the inside of the cabin of the vehicle in which the in-vehicle device is mounted, the cabin of the bus in which the in-vehicle device is mounted, and the like can be set as the predetermined space area that ensures safety.

System configuration diagram of the approach notification system of the first embodiment Control block diagram of external communication unit 110 Circuit diagram of the transmission processing unit 112 Flowchart of timer interrupt routine of communication control unit 111j A plan view of a general road illustrating a configuration example of a group of portable terminals Time chart illustrating how group representatives are changed sequentially Flowchart of reception interrupt routine of weak wireless node 120 Configuration diagram of the most main control table CT used by the mobile terminal 100 Flowchart of timer interrupt routine 1 of weak wireless node 120 Plan view of a general road illustrating the state of alarm forwarding within a group of mobile terminals Flowchart of timer interrupt routine 2 of weak wireless node 120 Plan view of a general road illustrating the operation of the fixed station Q of the present invention The flowchart which illustrates concretely the control system of the modification 2 of this invention Plan view of a general road illustrating the state of response transmission of a conventional portable terminal

100: Mobile terminal 110: External communication unit 120: Weak wireless node 800: Forced sleep terminal (transmission processing suppression means)
900: In-vehicle device GPC: Number of received communications within group KC: Number of received alarm transfer signals

Claims (8)

In an approach notification system that informs the terminal user of the approach of the vehicle by a portable terminal that detects wireless output from an in-vehicle device mounted on the vehicle,
The portable terminal is
An external communication unit that executes communication processing on the order of 100 m with the in-vehicle device;
A weak wireless node that performs short-distance communication processing of several m order with another portable terminal using a radio wave having a frequency lower than the frequency of the radio wave used by the external communication unit ;
The weak wireless node is
A group forming means for forming a temporary group from a plurality of the portable terminals in one space area capable of short-range communication by weak wireless;
Representative terminal determining means for determining only one representative terminal belonging to the group and representing the group;
The external communication unit of the representative terminal is
An approach notification system characterized in that transmission processing of a specific low-power radio signal to be transmitted from a mobile terminal belonging to the group is performed with respect to the approaching vehicle as a representative of the group . The external communication unit executes the communication process by specific low-power radio using a radio wave having a frequency of 1 GHz or more,
The approach notification system according to claim 1, wherein the weak wireless node executes the short-range communication processing by weak wireless using a radio wave having a frequency of 600 MHz or less. The representative terminal determination means, approach warning system according to claim 1 or claim 2 characterized by having a representative terminal changing means for sequentially changing the representative terminal in the group. The weak radio node, the vehicle that the radio output there from the device to other mobile terminals in the group, claims 1 to, characterized in that it comprises a vehicle approach information transmission means for transmitting Item 4. The approach notification system according to any one of Items3. A transmission process inhibiting means for outputting a transmission inhibition command for inhibiting the transmission process of the specific low-power radio signal from the portable terminal within a predetermined space area in which the safety of the terminal carrier is ensured. The access notification system according to any one of claims 1 to 4 , wherein In a portable terminal that notifies the approach of the vehicle by detecting a wireless output from an in-vehicle device mounted on the vehicle,
An external communication unit that executes communication processing on the order of 100 m with the in-vehicle device;
A weak wireless node that performs short-distance communication processing of several m order with another portable terminal using a radio wave having a frequency lower than the frequency of the radio wave used by the external communication unit;
The weak wireless node is
A group forming means for forming a temporary group from a plurality of the portable terminals in one space area capable of short-range communication by weak wireless;
Representative terminal determining means for determining only one representative terminal belonging to the group and representing the group;
The external communication unit of the representative terminal is
For the approaching vehicle, transmission processing of a specific low-power radio signal to be transmitted from a mobile terminal belonging to the group is performed as a representative of the group.
A portable terminal characterized by that. The representative terminal determining means includes representative terminal changing means for sequentially changing the representative terminal in the group.
The mobile terminal according to claim 6. The weak wireless node has vehicle approach information transmitting means for transmitting to the other mobile terminals in the group that there is a wireless output from the in-vehicle device.
The portable terminal according to claim 6 or 7, characterized in that

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