JP4100472B2 - Parent / child station danger detection ultrasonic transmitter / receiver - Google Patents

Description

  The present invention relates to an ultrasonic transmission / reception apparatus that is used, for example, for the purpose of preventing contact accidents between heavy equipment vehicles and surrounding workers in construction / civil engineering work and detects a risk between parent and child stations.

  Conventionally, as a parent / child station danger detection ultrasonic transmission / reception device used in construction / civil engineering work, the parent station includes a first transmission sensor, a first reception sensor, a control circuit, and a first alarm device, A second receiving sensor, a second transmitting sensor, a response circuit, and a second alarm device are provided. The master station is installed in a heavy equipment vehicle, for example, and the slave station is installed in a worker's helmet, vest, etc. (For example, refer to Patent Document 1 and Patent Document 2).

  For example, in the parent-child station danger detection ultrasonic transmitting / receiving apparatus described in Patent Document 2, the first transmission sensor of the parent station transmits the first ultrasonic wave so as to cover the dangerous area, and the second reception sensor of the child station is the first. When receiving the first ultrasonic wave, the second transmission sensor transmits the second ultrasonic wave, the first reception sensor of the master station receives the second ultrasonic wave, and detects that the slave station is present in the dangerous area. The master station transmits a third ultrasonic wave. The third ultrasonic wave received by the slave station is sorted by the sorting circuit of the slave station as the first ultrasonic wave or the third ultrasonic wave. The slave station selects that it has received the third ultrasonic wave, thereby detecting that it is in the dangerous area and outputting an alarm activation signal.

JP-A-1-12285 Japanese Patent No. 3202865

  The above-mentioned conventional apparatus is usually used in a situation where a plurality of workers with a slave station are working around a heavy machinery vehicle with a master station installed. When a plurality of heavy equipment vehicles installed with a vehicle are working close to each other, each of them transmits the first ultrasonic wave asynchronously separately. The second ultrasonic wave transmitted by the slave station in response to the sound wave is also received by another master station, and depending on the timing, it corresponds to the dangerous area for another master station, and the slave station actually However, there is a problem that the alarm may be generated irregularly even though it does not exist in the dangerous area.

  The present invention has been made in view of such a problem, and its purpose is to provide a slave station in the dangerous area of each master station without generating an alarm irregularly in each master station even when there are a plurality of master stations. It is an object of the present invention to provide a parent-child station danger detection ultrasonic transmission / reception device that can more accurately detect the presence of the presence of the.

In order to achieve the above object, the invention described in claim 1 is directed to a first transmission sensor that transmits a first ultrasonic wave so as to cover a dangerous area, and a second ultrasonic wave having a frequency different from the first frequency. A plurality of master stations including a first receiving sensor that receives the control signal and a control circuit;
A second reception sensor for receiving the first ultrasonic wave transmitted from the master station, a second transmission sensor for transmitting the second ultrasonic wave, and a second transmission when receiving the first ultrasonic wave a slave station and a response circuit for transmitting a second ultrasonic sensor, or Rannahli each master station is provided with a radio wave transmitting and receiving means for receiving a radio wave transmits a radio wave with a predetermined period, The radio wave transmitting / receiving means provided in any of the master stations becomes an oscillation station for any of the other master stations,
First transmitting sensor of the master station with the oscillation station transmits a first ultrasound based on the timing of receiving radio waves from emitting Fukyoku, the control circuit of the master station, transmission of the first ultrasound Detecting whether or not the slave station exists in the dangerous area from the time difference from the reception of the second ultrasonic wave to the second ultrasonic wave ,
The radio wave includes information for determining the oscillation station, and the radio wave transmitting / receiving means of the other master station that receives the radio wave is determined in advance from the information for determining the oscillation station included in the transmitted radio wave. It is determined whether or not the radio transmission / reception means of the transmission source parent station is an oscillation station based on the established rules, and if it is determined that the transmission / reception means of the transmission source parent station is an oscillation station, the oscillation station It is characterized by transmitting radio waves almost in synchronism with the radio waves .

When radio waves are transmitted from the oscillation station at a predetermined cycle and received at each parent station, each parent station transmits a first ultrasonic wave at a transmission timing based on the radio wave reception timing. Thereby, the transmission timings of the first ultrasonic waves of all the master stations are almost synchronized. When the master station receives the second ultrasound transmitted from the slave station in response to the first ultrasound from the master station, the second ultrasound is the first ultrasound of the other master station. Even if it was transmitted by the slave station in response to the error, it is generated irregularly because it is in response to the first synchronized ultrasonic wave from the other master station. is not. Therefore, when determining whether or not the slave station exists in the dangerous area based on the time difference from the transmission of the first ultrasonic wave of the master station to the reception of the second ultrasonic wave, it is determined more accurately than in the past. Can prevent the occurrence of irregular alarms. By providing radio wave transmission / reception means for all the master stations, it is possible to save the trouble of installing a separate oscillation station, and in any situation, the radio wave transmission / reception means of one of the multiple master stations can be It can be an oscillating station for any parent station. Further, no matter how the relative positional relationship among the plurality of master stations changes, the oscillation station can be determined based on a rule determined in advance from information for determining the oscillation station.

  Note that the transmission timing of the first ultrasonic wave of the master station may be transmitted at every timing of receiving the radio wave, but is not limited to this, and the master station is based on the timing of receiving the radio wave. The first ultrasonic wave may be transmitted at a predetermined cycle, and the first ultrasonic wave may be transmitted at the predetermined cycle until the next radio wave is received. This is effective when the period is longer than the period for transmitting the first ultrasonic wave from the master station.

According to a second aspect of the present invention, in the first aspect of the present invention, when it is determined that the radio wave transmitting / receiving means of the source master station is an oscillation station, information for determining the oscillation station is used as the oscillation station. The information is the same as the information for determining the oscillation station to be transmitted by the radio wave transmission / reception means of the master station that has become the station.
The invention according to claim 3 is the one according to claim 1 or 2 , wherein when the master station detects that the slave station is present in the dangerous area, the master station transmits a third ultrasonic wave, and the response circuit of the slave station is The first ultrasonic wave and the third ultrasonic wave are selected, and the presence of a dangerous area is detected based on the reception of the third ultrasonic wave. As a result, the slave station can recognize that it is in the dangerous area by selecting that the third ultrasonic wave has been received. Therefore, an alarm activation signal can be output as necessary.

  According to the present invention, since the master station transmits the first ultrasonic wave at the transmission timing based on the radio wave reception timing, the transmission timings of the first ultrasonic waves of all the master stations are synchronized. Therefore, when the master station receives the second ultrasound transmitted from the slave station in response to the first ultrasound from the master station, the second ultrasound is received. Is responsive to the first ultrasound of the other master station, but it is irregularly responsive to the substantially synchronized first ultrasound from the other master station. It is no longer what has occurred, and it is possible to prevent the occurrence of irregular alarms.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First reference form)
FIG. 1 is an explanatory diagram showing an example of a site to which a parent-child station danger detection ultrasonic transmission / reception apparatus of the present invention is applied, and FIG. 2 is an overall block diagram of the parent-child station danger detection ultrasonic transmission / reception apparatus according to a reference form of the present invention. It is. In the figure, as in the conventional example, the master station 1 is installed in a moving body such as a heavy machinery vehicle, and the slave station 2 is installed in a worker's helmet, vest, and the like. There are a plurality of mobile units in which the master station 1 is installed, and the master stations 1 may approach each other within a short-range range in which ultrasonic waves from the same slave station 2 can be received. To do.

  The master station 1 includes a transmission sensor 11, a reception sensor 12, a control circuit 13 that controls the transmission sensor 11 and the reception sensor 12, an alarm device 14, and a radio wave receiver (radio wave receiver) 15. The transmission sensor 11 and the reception sensor 12 include a plurality of sensors as necessary, and are arranged so that the sound field formed by all the sensors covers the dangerous area of the moving body.

  One slave station 2 includes a reception sensor 16, a transmission sensor 17, a response circuit 18, and an alarm device 19. The reception sensor 16 and the transmission sensor 17 of the slave station 2 are also composed of a plurality of sensors as necessary, so that the ultrasonic waves from the master station 1 can be received regardless of the posture of the worker. Be placed. The response circuit 18 controls the reception sensor 16 and the transmission sensor 17, and causes the transmission sensor to transmit the second ultrasonic wave when receiving the ultrasonic wave from the master station.

  In addition to the master station 1 and the slave station 2, an oscillation station 3 is provided. The oscillation station 3 may be fixedly installed at the site, or may be installed in a heavy equipment vehicle or another mobile body in which the master station 1 is installed. The oscillation station 3 includes a radio wave transmission means including a transmitter 100 having an oscillator that oscillates a reference pulse every period T, and a transmission antenna 102 that converts a signal from the transmitter 100 into a radio wave pulse and transmits the radio wave pulse. ing.

  A detailed block diagram of the control circuit 13 and the radio wave receiver 15 of the master station 1 is shown in FIG. The radio wave reception unit 15 includes a reception antenna 120 that receives radio wave pulses from the transmission antenna 102 and a receiver 122 that outputs a reference pulse from a signal from the reception antenna 120. The reference pulse from the receiver 122 is sent to the transmission pulse generation circuit 22 of the control circuit 13.

  The transmission pulse generation circuit 22 generates a transmission signal having a frequency f1 at every reference pulse timing from the reference pulse from the receiver 122 and the reference transmitter 24 having the frequency f1, and the transmission signal is amplified by the amplification circuit 23. The transmission sensor 11 is driven. The band pass filter / AMP 25 receives a reception signal from the reception sensor 12, filters a signal in a frequency band centered on the frequency f 2, and sends it to the distance measurement gate circuit 27. The delay circuit 26 receives a reference pulse from the receiver 122, outputs a signal delayed for a predetermined time, and sends the signal to the distance measurement gate circuit 27. Based on the signal from the delay circuit 26, the distance measurement gate circuit 27 generates several types of gate signals corresponding to the monitoring distance such as the dangerous distance and the attention distance. The signal discriminating circuit 28 compares the signal from the band pass filter / AMP 25 with a threshold value, compares it with a predetermined value of the signal width, etc., and cuts noise, and measures the distance between these pass signals and the distance. The AND of the gate signal from the gate circuit 27 is taken, and this AND signal is sent to the alarm signal output circuit 29. The alarm signal output circuit 29 obtains information on the distance to the slave station from the output gate, and classifies the frequency of the alarm sound and the interval of the alarm sound according to the degree of danger such as the danger distance and the attention distance. Output generation signal. In addition to the alarm sound generation signal, an alarm activation signal including an alarm display generation signal and a control external output signal is generated and output to the alarm device 14 and the outside. At the same time, the alarm signal output circuit 29 sends an alarm activation signal to the delay circuit 30. The delay circuit 30 outputs a signal delayed by a predetermined time (t 3), and the confirmation signal generation circuit 31 sends a trigger signal to the transmission pulse generation circuit 22 using the signal from the delay circuit 30.

  Returning to FIG. 2, the alarm device 14 generates an alarm sound in response to the alarm sound generation signal, performs an alarm display in response to the alarm display generation signal, and alerts the heavy equipment vehicle driver. Further, the operation of the heavy machinery vehicle can be stopped by inputting the control external output signal to the driving circuit of the heavy machinery vehicle. However, the monitoring distance can be one type and the alarm sound can be one type.

  A detailed block diagram of the response circuit 18 of the slave station 2 is shown in FIG. In FIG. 4, the band pass filter / AMP 42 receives a reception signal from the reception sensor 16, passes a signal in a frequency band centered on the frequency f <b> 1, and sends the signal to the signal determination circuit 43. The signal discriminating circuit 43 performs noise cutting by comparing the threshold value with a predetermined value of the signal width, and sends the passed signal to the signal selecting circuit 44. The signal selection circuit 44 selects whether the ultrasonic wave from the master station 1 is the first ultrasonic wave or the third ultrasonic wave. When the ultrasonic wave is the first ultrasonic wave, a signal is sent to the reply pulse generation circuit 47, When the ultrasonic wave is 3, the signal is sent to the alarm signal output circuit 45.

  As shown in FIG. 5, the signal selection circuit 44 generates a confirmation gate signal that generates a confirmation gate signal delayed by a predetermined time (t2 + t3) based on the first ultrasonic reception signal from the signal determination circuit 43. A return signal generation circuit 51 that generates a trigger signal delayed by a predetermined time (t2) based on the first ultrasonic wave reception signal from the circuit 50 and the signal determination circuit 43 and sends the trigger signal to the return pulse generation circuit 47. And an AND gate 52 that takes an AND of the confirmation gate signal and the signal from the signal determination circuit 43.

  The reply pulse generation circuit 47 receives the trigger pulse from the signal selection circuit 44, generates a reply signal having a frequency f2 from the reference transmitter 46, and the reply signal is amplified by the amplifier circuit 48 to drive the transmission sensor 17. It is like that.

  The transmission and reception timings of the parent / child station danger detection ultrasonic transmitting / receiving apparatus configured as described above will be described with reference to FIG.

  First, a radio wave pulse O is transmitted from the transmission antenna 102 of the oscillation station 3 every period T (FIG. 6A), and is received by the reception antenna 120 of each parent station 1. At this time, all the master stations 1 receive radio wave pulses at a timing that can be regarded as simultaneous. Then, with this radio wave pulse as a trigger, the first ultrasonic wave having the pulse width w1 is transmitted from the transmission sensor 11 of each master station 1 at the frequency f1. A transmission signal for the first ultrasonic wave of the master station 1 is represented by MT1. The first ultrasonic wave is received by the slave station 2 with a delay of a propagation time t1 proportional to the distance between the master station 1 and the slave station 2. This received signal is represented by RR1. From the reception of RR1, the slave station 2 passes the delay time t2 set by the signal selection circuit 44 to avoid reverberation and interference of the signal, and then sends the second ultrasonic wave having the frequency f2 and the pulse width w2 to the master station 1. Reply. The return signal for the second ultrasonic wave is represented by RT1. The second ultrasonic wave is received by the master station 1 with a delay of the propagation time t1. This received signal is denoted by MR1.

  The received signal MR1 is a monitoring gate signal corresponding to the monitoring distance set by the distance measurement gate circuit 27 (in this case, the gate signal corresponding to each of the dangerous distance and the attention distance is represented as a monitoring gate signal. AND) (FIG. 6 (d)). When the AND signal is output (FIG. 6E), an alarm activation signal is output from the alarm signal output circuit 29. At the same time, after the delay time t3 set by the delay circuit 30 in order to avoid reverberation and interference, the third ultrasonic wave having the pulse width w1 is transmitted again at the frequency f1. A transmission signal for the third ultrasonic wave of the master station 1 is represented by MT2. The third ultrasonic wave is received by the slave station 2 after the propagation time t1. This received signal is represented by RR2. The reception of the reception signal RR2 means that the slave station 2 is captured by the master station 1, in other words, the slave station 2 is within the monitoring area of the master station 1, and propagation Although there is a time delay (about 0.03 seconds when the distance is 10 m), the slave station 2 can recognize the danger information of the master station 1 within 0.1 seconds including the delay time. In the signal selection circuit 44 of the slave station 2, the confirmation gate signal (FIG. 6 (f)) and the reception signal RR2 are ANDed, and when the AND signal is output (FIG. 6 (g)), an alarm is issued. An alarm activation signal is output from the signal output circuit 45.

  Next, as shown in FIG. 9, a case is considered in which a plurality of master stations 1-1 and 1-2 are close to each other and a slave station 2 is present in the vicinity thereof. Assume that the distance between the master station 1-1 and the slave station 2 is L1, the distance between the master station 1-2 and the slave station 2 is L1 ', and L1> L1'.

  First, a radio wave pulse O is transmitted from the transmission antenna 102 of the oscillation station 3 every period T (FIG. 7A) and received by the reception antenna 120 of each master station 1. The master stations 1-1 and 1-2 transmit the first ultrasonic wave according to the transmission signal MT1 at a synchronized timing. Since the slave station 2 is closer to the master station 1-2 than the master station 1-1, the slave station 2 is delayed by a propagation time t1 ′ (= L1 ′ / v) proportional to the distance L1 ′ from the master station 1-2. The ultrasonic wave from the master station 1-2 is received first, and in response thereto, the reply signal RT1 delayed by the delay time t2 is generated. Since the confirmation gate signal generation circuit 50 of the signal selection circuit 44 of the slave station 2 receives the ultrasonic wave from the master station 1-2, it does not accept the received signal for a certain period of time. The first ultrasonic wave transmitted from the master station 1-1 received with a delay of propagation time t1 (= L1 / v> t1 ′) proportional to L1 is ignored. The slave station 2 transmits the second ultrasonic wave according to the reply signal RT1. The second ultrasonic wave is received by the master station 1-2 after the propagation time t1 ′, but the process at this time is the same as the case where the master station and the slave station are 1: 1 as described above, and L1 When 'is the distance within the monitoring area of the master station 1-2, the master station 1-2 transmits a third ultrasonic wave, and the slave station 2 outputs an alarm activation signal.

  The second ultrasonic wave is received as the received signal MR1 by the master station 1-1 after the propagation time t1. In this case, the processing in the master station 1-1 is the same as the processing in the case where the slave station 2 is located at a distance L11 ′ (= (t1 + t1 ′) · v / 2) corresponding to the propagation time of (t1 + t1 ′) / 2. It becomes. That is, if the distance L11 ′ is a distance outside the monitoring area of the master station 1-1, an AND signal between the monitor gate signal (FIG. 7 (d)) of the master station 1-1 and the reception signal MR1 is obtained. Even if it is taken, the AND signal is not output (FIG. 7E), and the alarm activation signal is not output. In this case, the distance L1 where the slave station 2 actually exists is always outside the monitoring area, and no erroneous detection occurs.

  On the other hand, when the distance L11 ′ (= (t1 + t1 ′) · v / 2) is a distance within the monitoring area of the parent station 1-1, the monitoring gate signal of the parent station 1-1 (FIG. 8D). ) And the reception signal MR1 are output (FIG. 8E), and an alarm activation signal is output. In this case, the distance L1 where the slave station 2 actually exists may be within the monitoring area or outside the monitoring area. When the slave station 2 is actually within the monitoring area, an alarm activation signal should be output, and no false alarm will occur. On the other hand, the case where the slave station 2 actually exists outside the monitoring area will be further examined. In this case, if the distance corresponding to the monitoring area set in the master station 1-1 is M,

が成り立ち、Ｌ１１’＝（Ｌ１＋Ｌ１’）／２と置き換えることができるから、上式は、

And can be replaced with L11 ′ = (L1 + L1 ′) / 2.

と書き直せる。言い換えれば、一方の親局１−１と子局２との距離Ｌ１と他方の親局１−２と子局２との距離Ｌ２との合計が、監視距離の２倍以下である場合で且つ、Ｌ１＞Ｍである場合、さらに言い換えれば親局１−１と子局２との実際の距離Ｌ１が監視距離Ｍよりも大きい場合に、誤警報となる。しかしながら、誤警報になる場合は、上記関係が成り立つ規則的な場合のみである。子局２が監視距離内にいる場合には、必ず監視ゲート信号と受信信号とのＡＮＤ信号が出力され、警報は出力される。よって不規則な誤警報・誤検出を防ぐことができる。

Can be rewritten. In other words, the sum of the distance L1 between one master station 1-1 and the slave station 2 and the distance L2 between the other master station 1-2 and the slave station 2 is less than twice the monitoring distance and When L1> M, in other words, when the actual distance L1 between the master station 1-1 and the slave station 2 is larger than the monitoring distance M, a false alarm is generated. However, a false alarm is only a regular case where the above relationship holds. When the slave station 2 is within the monitoring distance, an AND signal of the monitoring gate signal and the reception signal is always output, and an alarm is output. Therefore, irregular false alarms and false detections can be prevented.

(Second reference form)
Next, FIG. 10 is an overall block diagram of the parent-child station danger detection ultrasonic transmitting / receiving apparatus representing the second reference embodiment of the present invention. In the figure, the same parts as those of the first reference embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In this reference embodiment includes a clock pulse generating circuit 21 for outputting a clock pulse, the clock pulse from the generator 21 is delivered to the transmission pulse generator 22.

  The radio wave receiver 15 receives a radio wave including time information from the oscillation station 3 and outputs a reference pulse based on the radio wave. The transmission pulse generation circuit 22 includes a counting circuit that counts the clock pulses from the clock pulse generation circuit 21, and generates a transmission signal having a frequency f1 from the reference transmitter 24 every predetermined pulse count. This transmission signal is amplified by the amplifier circuit 23 to drive the transmission sensor 11, and the first ultrasonic wave is transmitted.

  Until the radio wave receiving unit 15 receives the next radio wave, the first ultrasonic wave is transmitted at a timing at which the counting circuit of the transmission pulse generating circuit 22 counts a predetermined number of clock pulses. When the next reference pulse is output from the radio wave receiver 15, the counting circuit of the transmission pulse generation circuit 22 is reset, and the counting of the clock pulse is started again with the reference pulse as a reference.

  In this way, the transmission timings of the first ultrasonic waves transmitted from all the master stations 1 can be synchronized every time radio waves are received. When the transmission period of the radio wave from the oscillation station 3 is longer than the period for transmitting the first ultrasonic wave from the parent station, the first ultrasonic wave is transmitted at the timing of the clock pulse in each parent station 1 during that period. Therefore, there is a possibility that a deviation in transmission timing may occur between the master stations 1. However, since synchronization is established again by the next radio wave, the deviation in transmission timing is small and almost all of the master stations 1 The first ultrasonic wave can be transmitted at the synchronized timing.

According to the second reference embodiment, not only a dedicated oscillation station as the oscillation station 3, in other words, not only an oscillation station that outputs a radio wave pulse every period T for transmitting the first ultrasonic wave, but also an arbitrary station. The oscillation station can be used. Therefore, not only the oscillation station 3 installed near the site where the master station 1 and the slave station 2 exist, but also a general-purpose public oscillation station 3 can be used. Specifically, as the general-purpose oscillation station 3, a standard radio wave transmission station that transmits standard radio waves used in a radio timepiece or a GPS satellite that transmits GPS radio waves can be used. Such a general-purpose oscillation station 3 periodically transmits a radio wave including time information, and all the master stations can transmit the first ultrasonic wave at a timing based on the radio wave. If the general-purpose oscillation station 3 is used, the setting work of the oscillation station 3 is not required, and the work at the site becomes easy. On the other hand, in a site where radio waves from standard radio wave transmission stations or GPS satellites do not reach, such as work in a tunnel, an oscillation station 3 having an arbitrary oscillation period may be placed and used. In this way, it can be used flexibly according to the situation at the site.

(Embodiment)
Next, FIG. 11 is an overall block diagram of the parent-child station danger detection ultrasonic wave transmitting / receiving apparatus representing the embodiment of the present invention. In the figure, the same parts as those of the first reference embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, each master station 1 includes a radio wave transmission / reception unit 15-1 as a radio wave transmission / reception means instead of the radio wave reception unit 15, and a plurality of parent stations 1 are in an area where radio wave transmission / reception can be performed. In addition, according to a predetermined rule, the radio wave transmission / reception means of any of the master stations 1 becomes the oscillation station 3, and the master station 1 in the area synchronizes with the radio wave from the oscillation station 3. The first ultrasonic wave having the pulse width w1 is transmitted from the transmission sensor 11 of the station 1 at the frequency f1.

  The radio wave transmission / reception unit 15-1 includes a transmission / reception antenna 130, a transmitter / receiver 132, a clock pulse generation circuit 134, a control unit 136, and a memory 138 that stores an ID number. As the ID number, a unique number is assigned to each master station 1 in advance. The memory 138 stores the ID number of both the unique ID number and the acquired ID number acquired after that, and the radio wave transmitting / receiving means 15-1 of which parent station 1 becomes the oscillation station 3 based on this ID number. It becomes information to decide. The initial value of the acquisition ID number is a unique ID number.

  The control unit 136 of the radio wave transmission / reception unit 15-1 creates a signal including ID information for each period T based on the clock pulse generated by the clock pulse generation circuit 134, and sends the signal to the transmission / reception unit 132. Radio waves are transmitted from 130 (step S12 in FIG. 12). This included ID information is the acquired ID number of the transmission source master station 1 recorded in the memory 138. At the same time as the signal is sent from the control unit 136 to the transceiver 132, the signal from the control unit 136 of the radio wave transmission / reception unit 15-1 is sent to the transmission pulse generation circuit 22 of the control circuit 13 of the master station 1. At this timing, the first ultrasonic wave is transmitted (step S14 in FIG. 12).

  In addition, the radio wave transmission / reception unit 15-1 receives a radio wave including code information transmitted at a specific timing of the master station 1 from another master station 1 in an area where radio waves can be transmitted / received at an arbitrary time. (Step S16 in FIG. 12). The ID information included in the received signal is decoded by the control unit 136 and compared with the acquired ID number of the master station 1 stored in the memory 138 (step S18 in FIG. 12). Here, the predetermined rule is a rule that the number with the smaller ID number is adopted. This means that the master station 1 with the smaller unique ID number is always followed, and the radio wave transmission / reception unit 15-1 of the parent station 1 with the smaller unique ID number becomes the oscillation station 3.

  Specifically, if the received ID information is smaller than the current acquired ID number, the acquired ID number in the memory 138 is rewritten with the received ID number as a new acquired ID number (step S20 in FIG. 12). In addition, based on the reception timing, the radio wave including the acquired ID information is transmitted from the transmission / reception antenna 130 every period T (step S24 in FIG. 12). At the same time, the first ultrasonic wave is transmitted (step S26 in FIG. 12). On the other hand, when the received ID information is larger than the current acquired ID number, the acquired ID number is not rewritten and is sent from the control unit 136 at every cycle T without changing the current acquired ID number. Based on the signal (step S12 in FIG. 12), the first ultrasonic wave is transmitted (step S14 in FIG. 12).

Consider a case where two master stations 1 are close to each other so that they can transmit and receive each other (see FIG. 13). In this case, the master station 1 to the radio wave transceiver 15-1 of the parent station 1 has the next oscillation station 3, a large unique ID number _{N 2 (N 2> N 1} ) with a small unique ID numbers _{N 1,} the oscillation station The first ultrasonic wave is transmitted based on the timing at which the radio wave from 3 is received. Further, although the master station 1 having the unique ID number N ₁ receives the radio wave from the master station 1 having the unique ID number N ₂ , the own radio wave transmitting / receiving unit 15-1 is connected regardless of the reception of the radio wave. As the oscillation station 3, the first ultrasonic wave is transmitted. Therefore, the two master stations 1 simultaneously transmit the first ultrasonic wave based on the reception timing of the radio wave of the oscillation station 3. In addition, the master station 1 having the unique ID number N ₂ transmits a radio wave including the acquired ID number N ₁ as code information almost in synchronization with the master station 1 having the unique ID number N ₁ .

Next, it is assumed that the master station 1 having another unique ID number N ₃ (N ₂ > N ₃ > N ₁ ) approaches the master station 1 having the unique ID number N _{2 so as} to be able to transmit and receive radio waves. . However, the master station 1 having the unique ID number N ₃ and the master station 1 having the unique ID number N ₁ are not close to each other so as to be able to transmit and receive radio waves. In this case, the master station 1 with a unique ID number _{N 3,} since receiving a radio wave including the acquired ID number _{N 1} from the master station 1 with a unique ID number _{N 2} as the code information, a unique ID number _{N 2} master station 1 radio transmitting and receiving unit 15-1 of the base station 1 with has next oscillation station 3, the unique ID numbers N _3, based on the timing of receiving radio waves from the oscillation station 3, transmits the first ultrasonic Will do. Further, the master station 1 having the unique ID number N ₃ transmits a radio wave including the acquired ID number N ₁ as code information almost in synchronization with the master station 1 having the unique ID number N ₁ . As a result, consider a set among a large number of master stations 1, and the set is a set of master stations 1 in which the master station 1 belonging to the set can transmit and receive radio waves with any of the master stations 1 belonging to the set. , All the master stations 1 belonging to the set transmit the first ultrasonic wave in synchronization with the master station 1 having the smallest unique ID number in the set, and set the smallest unique ID number. The radio wave is output in synchronization with the acquisition ID number.

  According to this embodiment, since all the master stations 1 are provided with the radio wave transmission / reception unit 15-1, it is possible to save the trouble of installing a separate oscillation station 3, and what is the relative positional relationship between the plurality of master stations 1. Even in such a case, the radio wave transmission / reception unit 15-1 of any one of the master stations 1 can operate as the oscillation station 3 of any other master station 1.

  In each of the above embodiments, separate transmission sensors and reception sensors can be used for each of the master station and the slave station. However, it is of course possible to use a broadband transmission / reception integrated sensor.

It is explanatory drawing showing an example of the field where the parent-child station danger detection ultrasonic transmission / reception apparatus of this invention is applied. 1 is an overall block diagram of a parent-child station danger detection ultrasonic transmitting / receiving apparatus according to a reference embodiment of the present invention. It is a detailed block diagram of the control circuit of the master station. It is a detailed block diagram of a response circuit of a slave station. It is a block diagram of the signal selection circuit of the response circuit of a slave station. It is a timing chart of transmission and reception of the parent / child station danger detection ultrasonic transmission / reception apparatus. It is a timing chart of transmission and reception of the parent / child station danger detection ultrasonic transmission / reception apparatus. It is a timing chart of transmission and reception of the parent / child station danger detection ultrasonic transmission / reception apparatus. It is explanatory drawing showing arrangement | positioning of a master station and a slave station. It is a whole block diagram of the parent-child station danger detection ultrasonic transmission / reception apparatus which concerns on the 2nd reference form of this invention. 1 is an overall block diagram of a parent-child station danger detection ultrasonic transmission / reception device according to an embodiment of the present invention. It is a flowchart figure showing the operation | movement of one certain master station in embodiment. It is explanatory drawing showing the relationship of the some master station in embodiment.

Explanation of symbols

1 Master station 2 Slave station 3 Oscillating station 11 Transmitting sensor (first transmitting sensor)
12 Receiving sensor (second receiving sensor)
13 Control circuit 15 Radio wave receiver (Radio wave receiving means)
15-1 Radio transmitter / receiver (Radio transmitter / receiver)
16 Receiving sensor (second receiving sensor)
17 Transmitting sensor (first transmitting sensor)
18 Response circuit 100 Transmitter 102 Transmitting antenna

Claims (3)

A plurality of first transmission sensors that transmit the first ultrasonic wave so as to cover the dangerous area, a first reception sensor that receives a second ultrasonic wave having a frequency different from the first frequency, and a control circuit. With the master station
A second reception sensor for receiving the first ultrasonic wave transmitted from the master station, a second transmission sensor for transmitting the second ultrasonic wave, and a second transmission when receiving the first ultrasonic wave a slave station and a response circuit for transmitting a second ultrasonic sensor, or Rannahli each master station is provided with a radio wave transmitting and receiving means for receiving a radio wave transmits a radio wave with a predetermined period, The radio wave transmitting / receiving means provided in any of the master stations becomes an oscillation station for any of the other master stations,
First transmitting sensor of the master station with the oscillation station transmits a first ultrasound based on the timing of receiving radio waves from emitting Fukyoku, the control circuit of the master station, transmission of the first ultrasound Detecting whether or not the slave station exists in the dangerous area from the time difference from the reception of the second ultrasonic wave to the second ultrasonic wave ,
The radio wave includes information for determining the oscillation station, and the radio wave transmitting / receiving means of the other master station that receives the radio wave is determined in advance from the information for determining the oscillation station included in the transmitted radio wave. It is determined whether or not the radio transmission / reception means of the transmission source parent station is an oscillation station based on the established rules, and if it is determined that the transmission / reception means of the transmission source parent station is an oscillation station, the oscillation station A parent-child station danger detection ultrasonic transmission / reception apparatus characterized by transmitting radio waves almost in synchronization with radio waves of When it is determined that the radio transmission / reception means of the transmission source master station is an oscillation station, information for determining the oscillation station is transmitted to the oscillation station transmitted by the radio transmission / reception means of the parent station that is the oscillation station. The parent-child station danger detection ultrasonic transmitting / receiving apparatus according to claim 1 , wherein the information is the same as information for determining . When the master station detects that the slave station is present in the dangerous area, the master station transmits a third ultrasonic wave, and the response circuit of the slave station performs selection between the first ultrasonic wave and the third ultrasonic wave. the third child station danger detected ultrasonic transmitting and receiving apparatus according to claim 1 or 2, wherein the detecting the presence of the hazardous area based on the received ultrasonic waves.

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