JP2011146965A - Telegram message transmitting apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To present a novel system for preventing erroneous transmission of telegram messages. <P>SOLUTION: A telegram message transmitting apparatus 1 generates a transmitting telegram message by a processing section 10 and also generates a verifying telegram message as a telegram message corresponding uniquely to the transmitting telegram message. Moreover, a modulating section 20 of the telegram message transmitting apparatus 1 executes a first modulation process and a second modulation process to generate a combined carrier signal including the carrier component of the transmitting telegram message and the carrier component of the verifying telegram message. A frequency band component of the transmitting telegram message is extracted through a transmitting filter 30 and is then transmitted to a rail by a transmitting section 40. Meanwhile, the combined carrier signal output from the modulating section 20 is demodulated by a demodulating section 50 and thereby the transmitting telegram message and the verifying telegram message can be extracted. Here, the processing section 10 executes a first collating process for the transmitting telegram message and a second collating process for the verifying telegram message. If any one of the results of collation in the first collating process and the second collating process is noncompliant, transmission of the transmitting telegram message by the transmitting section 40 is stopped under the control of the processing section 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a message transmission device and a message transmission method.

  As a system for transmitting telegrams, for example, an automatic train control system (ATC (Automatic Train Control)) is known in the railway field. In ATC, the ground device that functions as a telegram transmission device has a track circuit (rail) provided for each block section, such as the identification code of the track circuit, the number of open sections to the block section where the preceding train is located, etc. A message containing information is transmitted repeatedly. The on-board device mounted on the train receives a message from the track circuit (rail) of the blocked section while passing through the blocked section, and controls the operation of the brake according to the brake pattern generated based on the received message. Realize vehicle speed control.

  In such a telegram transmission system, when a failure or abnormality occurs in the telegram transmission device, an erroneous telegram can be transmitted, so a technique for performing so-called feedback collation is known (for example, Patent Document 1). Feedback collation is a technique for verifying whether or not there is an error in a message by sending and feeding back a message and comparing and collating with the message at the time of generation.

JP-A-9-307534

  However, in the case of feedback collation in which collation of messages is performed in units of messages, it is necessary to wait for collation until the entire message to be transmitted is fed back. Can not do. For this reason, an erroneous message corresponding to at least one message is transmitted to the transmission destination.

  For example, in the above-mentioned ATC, even if one electronic message is used, an erroneous message on the on-board device side can lead to a major accident, and it is safe to apply the conventional feedback verification method as it is. There was a problem in terms of.

  In addition, in the conventional method of feeding back and collating a transmitted message, if the message does not contain information that changes every transmission such as a serial number, a failure in which the same message is repeatedly transmitted cannot be detected, and the failure becomes latent. There was also a fear.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to propose a new mechanism for preventing erroneous transmission of electronic messages.

The first form for solving the above problems is:
Transmission message generation means (for example, the processing unit 10 of FIG. 1) for generating a transmission message (for example, the transmission message of FIG. 2);
Verification message generation means (for example, the processing unit 10 of FIG. 1) that generates a verification message (for example, the verification message of FIG. 2) corresponding to the transmission message according to a generation rule determined in advance based on the transmission message;
A transmission telegram carrier component obtained by modulating a signal of a predetermined message transmission frequency by a predetermined message modulation method based on the transmission message, and a signal of a predetermined verification frequency different from the message transmission frequency A modulation means (for example, the modulation unit 20 in FIG. 1) that generates a combined carrier signal obtained by combining a verification message carrier wave component modulated by a predetermined verification message modulation method based on
Transmission message signal extraction means (for example, transmission filter unit 30 in FIG. 1) for extracting the signal of the message transmission frequency from the combined carrier signal generated by the modulation means;
Output means for outputting the signal extracted by the transmission telegram signal extraction means to a predetermined destination (for example, the transmission unit 40 in FIG. 1);
Demodulating means for obtaining a verification message carried by a verification message carrier component of the combined carrier signal by demodulating the combined carrier signal generated by the modulation means in a demodulation method corresponding to the verification message modulation method (For example, the demodulator 50 in FIG. 1);
Collation means (for example, the processing unit 10 in FIG. 1) for collating the verification message acquired by the demodulation means with the verification message generated by the verification message generation means;
A deterrence control unit (for example, the processing unit 10 in FIG. 1) that controls to suppress the external output when the collation result of the collation unit is incompatible;
Is a telegram transmission apparatus (for example, the telegram transmission apparatus 1 in FIG. 1).

As another form,
A verification message generation step for generating a verification message corresponding to the transmission message according to a predetermined generation rule based on a given transmission message;
A transmission telegram carrier component obtained by modulating a signal of a predetermined message transmission frequency by a predetermined message modulation method based on the transmission message, and a signal of a predetermined verification frequency different from the message transmission frequency A combined carrier signal generation step for generating a combined carrier signal by combining a verification message carrier wave component modulated by a predetermined verification message modulation method based on
A transmission message signal extraction step for extracting a signal of the message transmission frequency from the generated combined carrier signal;
An output step of externally outputting the extracted signal toward a predetermined destination;
A demodulation step for acquiring a verification message carried in the synthesized carrier signal by demodulating the generated synthesized carrier signal in a demodulation method corresponding to the verification message modulation method;
A suppression control step for performing control to suppress the external output when the acquired verification message and the verification message generated in the verification message generation step are incompatible;
A message transmission method including

  According to the first form and the like, a verification message corresponding to the transmission message is generated according to a predetermined generation rule based on the transmission message. Then, a synthesized carrier signal is generated by synthesizing a transmission telegram carrier component obtained by modulating a signal for transmitting a message and a verification message carrier component obtained by modulating a signal for the verification frequency, and a message is generated from the synthesized carrier signal. After extracting the signal of the transmission frequency, it is externally output toward a predetermined transmission destination. On the other hand, by demodulating the synthesized carrier signal with a demodulation method corresponding to the verification message modulation method, the verification message carried in the verification message carrier component is acquired, and the acquired verification message and the generated Check against the original verification message. And when the collation result is nonconformity, control which suppresses external output is performed.

  Instead of generating only a signal of a transmission telegram carrier that is finally output to the outside, a composite carrier signal is generated by synthesizing a verification message carrier of another frequency (verification frequency) with the transmission telegram carrier. Accordingly, it can be said that there is very little possibility that a failure that causes an error in the transmission message carried by the transmission message carrier component of the same signal in the state where there is no error in the verification message carried by the verification message carrier component. Therefore, in the first embodiment or the like, it is possible to prevent an external output of an erroneous transmission telegram by performing feedback collation of the verification telegram and suppressing the external output in the case of nonconformity.

Moreover, as a second form, it is a telegram transmission apparatus of the first form,
The demodulation means demodulates the combined carrier signal generated by the modulation means in a demodulation method corresponding to the electronic message modulation method, so that the transmission message carried in the transmission message carrier component of the combined carrier signal is changed. Get more,
The collation means further collates the transmission message acquired by the demodulation means and the transmission message generated by the transmission message generation means;
The suppression control means performs control to suppress the external output when any of the verification result of the verification message by the verification means and the verification result of the transmission message is incompatible.
You may comprise a message | telegram transmission apparatus.

  According to the second aspect, the demodulator obtains a transmission telegram carried by the transmission telegram carrier component by demodulating the combined carrier signal by a demodulation scheme corresponding to the telegram modulation scheme. Then, the collation unit collates the transmission message acquired by the demodulation unit and the transmission message generated by the transmission message generation unit, and either the verification result of the verification message or the verification result of the transmission message is incompatible. In this case, control to suppress external output is performed. By performing external output suppression control in consideration of not only the verification message verification result but also the verification result of the transmission message itself, it is possible to reliably prevent an erroneous message from being transmitted.

Further, as a third form, the telegraphic transmission device of the first or second form,
The modulation means performs the modulation using a frequency higher than the message transmission frequency as the verification frequency, and the length of the carrier time for one verification message in the verification message carrier component is in the transmission message carrier component. Generating the combined carrier signal shorter than the transmission time length of one transmission message;
Before the external output of the signal carrying one transmission message is completed, the verification unit may complete the verification for one verification message.

  According to the third embodiment, the modulation means performs modulation using a frequency higher than the transmission frequency for the message as the verification frequency, and the length of the carrier time for one verification message in the verification message carrier component is the transmission message carrier. A composite carrier signal shorter than the carrier time length of one transmission message in the component is generated. As a result, before the external output of the signal carrying one transmission message is completed, the verification for one verification message by the verification means is completed. That is, since verification message verification is completed before external output of the entire transmission message (one transmission message) is not completed, external output of the transmission message can be quickly suppressed if the verification result is incompatible.

Further, as a fourth form, a telegram transmission apparatus of the third form,
The modulation means generates the composite carrier signal so as to repeatedly carry the verification message in the verification message carrier component while one transmission message is carried in the transmission message carrier component (for example, FIG. 7),
You may comprise a message | telegram transmission apparatus.

  According to the fourth embodiment, the modulation means generates the composite carrier signal so that the verification message carrier component repeatedly carries the verification message while the transmission message carrier component carries one transmission message. As a result, it is possible to guarantee the correct transmission of the message over the entire period during which one transmission message is output externally.

In addition, as a fifth form, any one of the first to fourth form of message transmission device,
The verification message generation means includes the verification message (for example, the verification message of FIG. 2, FIGS. 6 (1) and (2)) including at least a copy of a part or all of the transmission message generated by the transmission message generation means. Generate a verification message),
You may comprise a message | telegram transmission apparatus.

  According to the fifth embodiment, the verification message generation unit generates a verification message including at least a part or all of a copy of the transmission message generated by the transmission message generation unit. As a result, the collation by the collation means is also performed on the duplicate portion of the transmitted message. Therefore, verification of the verification message also verifies the content of the transmission message, and verification equivalent to the verification of the transmission message is realized.

Further, as a sixth form, any one of the first to fifth forms of message transmission device,
The verification message generation means generates the verification message (for example, the verification message of FIG. 6 (2)) including identification information for identifying each verification message.
You may comprise a message | telegram transmission apparatus.

  According to the sixth embodiment, the verification message generation unit generates a verification message including identification information for identifying each verification message. When the verification unit verifies the verification message, by monitoring the change in the identification information of the verification message, it is possible to detect a failure or abnormality in which the same message is repeatedly output to the outside.

The block diagram which shows an example of a function structure of a message transmission apparatus. The figure which shows an example of a transmission message and a verification message. The timing chart of the transmission of a transmission message and the collation of a verification message. The block diagram which shows an example of a function structure of the message | telegram transmission apparatus in a modification. The block diagram which shows an example of a function structure of the message | telegram transmission apparatus in a modification. The figure which shows an example of the verification message | telegram in a modification. The timing chart of the transmission message transmission in a modification.

  Hereinafter, an example of an embodiment suitable for the present invention will be described with reference to the drawings. In the following embodiment, an embodiment in which the present invention is applied to a telegram transmission device that transmits and transmits a telegram on a rail will be described as a type of railway security device. However, embodiments to which the present invention can be applied are not limited to this.

  In the present embodiment, a unit of data flowing through a transmission path (network) is referred to as a “message”. The electronic message may be, for example, a “frame” or a “packet”.

  When a train enters the track circuit, the track of the signal sent from the sending end side of the track circuit is short-circuited between the left and right rails by the wheel shaft of the vehicle and the axle. This is a device that detects that a train is present in the track circuit by utilizing the fact that the power reception level on the receiving side of the circuit is lowered.

  A telegram transmission device 1 according to the present embodiment is used as one of ground devices of an automatic train control system (ATC (Automatic Train Control)) which is a kind of a security system, for example, and is installed for each track circuit, and the corresponding own track. It plays the role of sending telegrams to the circuit rails. In ATC, the on-board device mounted on the train receives a message from the rail of the closed section while passing through the closed section, and controls the operation of the brake according to the brake pattern generated based on the received message. Realizes vehicle speed control.

1. Configuration FIG. 1 is a block diagram showing a functional configuration of a telegram transmission apparatus 1 according to the present embodiment. The electronic message transmission apparatus 1 includes a processing unit 10, a modulation unit 20, a transmission filter unit 30, a transmission unit 40, a demodulation unit 50, and a communication unit 60.

  The processing unit 10 is a processing circuit unit that generates a telegram (hereinafter referred to as “transmission telegram”) to be transmitted to the rail of the own track circuit. Based on the information to be notified to the train that has passed through the track circuit (hereinafter referred to as “train notification target information”), the processing unit 10 and a collation / verification message corresponding to the transmission message (Hereinafter, referred to as “verification message”). Then, the generated transmission message and the verification message are stored in the storage unit 12 as the generation transmission message 121 and the generation verification message 123, respectively, and then output to the modulation unit 20 in the subsequent stage. The function of the processing unit 10 is realized by a processor such as a CPU (Central Processing Unit).

  The storage unit 12 is configured by a storage device such as a ROM (Read Only Memory), a flash ROM, or a RAM (Random Access Memory), and the processing unit 10 controls a system program for controlling the message transmission device 1 or the processing unit 10 includes Various programs and data for generating and collating electronic messages are stored. The storage unit 12 is also used as a work area that temporarily stores various programs executed by the processing unit 10, data being processed in various processes, processing results, and the like.

  FIG. 2 is a diagram illustrating an example of a transmission message and a verification message in the present embodiment. The transmission message is configured as a total 56-bit data string including, for example, an 8-bit header part, a 40-bit data part, and an 8-bit check code part.

  The header part is a part that is provided at the head of the message and stores information such as a flag used for detecting the start position of the message and the type of the message. The data part is a part in which information of transmission contents is stored. For example, information such as a line section in which the own track circuit is laid, an A / B line, a track circuit ID, and the number of open sections is stored. The check code part is a part for storing a code for detecting a bit error in a message, and stores, for example, a CRC (Cyclic Redundancy Check) code.

  Based on the train notification target information, the processing unit 10 generates a transmission message and a verification message according to a predetermined generation rule. The verification message may be any message as long as it is a message that can be generated uniquely according to a certain generation rule based on the transmitted message. In the present embodiment, the processing unit 10 generates a verification message by duplicating the entire transmission message as shown in FIG.

  The modulation unit 20 includes a DSP (Digital Signal Processor) and the like, and is a functional unit that performs modulation processing based on a transmission message and a verification message output from the processing unit 10 by digital signal processing. The modulation unit 20 simultaneously performs the first modulation process related to the transmission message and the second modulation process related to the verification message, and obtains the carrier component of the transmission message obtained in the first modulation process and the second modulation process. A synthesized carrier wave signal is generated by synthesizing the carrier wave component of the verification message.

  More specifically, the first modulation process is a process of performing MSK (Minimum Shift Keying) modulation on a predetermined transmission message carrier frequency (hereinafter referred to as “message transmission frequency”). The second modulation process is a process for performing MSK modulation on a predetermined carrier frequency of the verification message (hereinafter referred to as “verification frequency”).

  In the present embodiment, the verification frequency is higher than the message transmission frequency. Considering the electrical performance of ground devices and on-vehicle devices in practical use, the carrier frequency is set to 1 kHz or less, the frequency bandwidth is set to about 25 to 100 Hz, and the verification frequency is higher than the frequency for transmitting the telegram. Select the frequency band. In this case, it is preferable to select the band so that the transmission speed of the transmission message is about 25 to 100 bps (bit per second) and the transmission speed of the verification message is about 3 to 10 times this value.

  The reason for making the verification frequency higher than the frequency for transmitting a message is to make the time length related to the conveyance for one verification message shorter than the time length related to the conveyance for one transmission message. Since the same MSK modulation is adopted for both the first modulation scheme and the second modulation scheme, the verification message with a higher frequency has a shorter carrier time length than the transmission message with a lower frequency. By doing in this way, it becomes possible to complete collation for one verification telegram before transmission for one transmission telegram is completed. If the verification result is incompatible, the transmission of the transmission message can be stopped immediately, so that even the first transmission message that was about to be transmitted can be stopped halfway. To prevent.

  The modulation employed for each of the first modulation scheme and the second modulation scheme is not limited to MSK modulation. If the time length related to the transport for one verification message is shorter than the time length related to the transport for one transmission message, another modulation method may be adopted, and the first modulation method and the second modulation method may be adopted. Different modulation methods may be used for different methods.

  The transmission filter unit 30 is a signal extraction circuit that extracts a message transmission frequency signal from the combined carrier signal output from the modulation unit 20. The transmission filter unit 30 is configured by a filter circuit such as a low-pass filter or a band-pass filter. The message transmission frequency signal that has passed through the transmission filter unit 30 is output to the transmission unit 40.

  The transmission unit 40 is a transmitter for physically transmitting (transmitting) the signal that has passed through the transmission filter unit 30 to the rail of the own track circuit, and the function of outputting the signal that has passed through the transmission filter unit 30 to the outside Make. The transmission unit 40 operates in accordance with the transmission control signal output from the processing unit 10. When the transmission stop control signal is input from the processing unit 10, the transmission unit 40 stops transmission of the transmission telegram signal to the rail.

  The demodulator 50 is a detector that demodulates the combined carrier signal input from the modulator 20 and extracts a transmission telegram and a verification telegram. The demodulator 50 includes a DSP (Digital Signal Processor) or the like and performs demodulation by digital signal processing. Specifically, a demodulation process corresponding to the first modulation scheme (MSK modulation for the telegram transmission frequency band) is executed to acquire a transmission telegram from the combined carrier signal, and the second modulation scheme (MSK for the verification frequency band). Demodulation processing corresponding to (modulation) is executed to obtain a verification message, and output to the processing unit 10 as a demodulation transmission message 125 and a demodulation verification message 127, respectively.

  The processing unit 10 performs a second collation process for collating the demodulation verification message 127 input from the demodulation unit 50 with the previously generated generation verification message 123, and also generates the demodulation transmission message 125 previously stored with the generation transmission message 121. The first matching process for matching is performed. Then, when it is determined that the collation result is incompatible in any of the collation processes, a transmission stop control signal is output to the transmission unit 40 to control transmission of the transmission telegram to the rail. In addition, a failure notification instruction signal is output to the communication unit 60, and control is performed so as to notify the external device of the failure of the message transmission device 1.

  The communication unit 60 is a communication device that performs wired communication or wireless communication with an external device such as another track circuit or a central information management device. When the failure notification instruction signal is input from the processing unit 10, the communication unit 60 generates a failure notification signal for notifying the external device of a failure of the message transmission device 1 and transmits the failure notification signal to the external device. This function is realized by, for example, a wired communication module that performs communication via a wired cable, a wireless communication module that performs wireless LAN, spread spectrum communication, or the like.

2. Operation FIG. 3 is a timing chart conceptually showing a flow of time from when a message is output from the processing unit 10 until the collation processing by the processing unit 10 is completed and transmission stop control of the transmission unit 40 is performed. Yes, the verification process is a diagram focusing on the verification message. In FIG. 3, the time is shown on the horizontal axis, and the operation time of each functional unit is shown as a time zone on the horizontal axis.

  First, the processing unit 10 starts outputting the generated transmission message and verification message to the modulation unit 20 at time t1. And the modulation | alteration part 20 will start a 1st modulation process and a 2nd modulation process simultaneously in parallel at the time t2, if a transmission message | telegram and a verification message | telegram are input from the process part 10. FIG.

  The modulation unit 20 outputs a combined carrier signal generated by performing the first modulation process and the second modulation process as needed. However, while the modulation for one transmission telegram takes until time t10, the modulation for one verification telegram ends at time t4. Therefore, the transmission message is included in the combined carrier signal from time t2 to time t10, but the verification message is included only from time t2 to time t4.

  Then, the transmission filter unit 30 outputs the carrier signal of the transmission message from which the frequency band component of the verification message has been cut to the transmission unit 40. Then, the transmission unit 40 transmits (transmits) the signal that has passed through the transmission filter unit 30 to the rail. Transmission of the signal by the transmission unit 40 is continued as long as the combined carrier signal is output from the modulation unit 20 (time t10).

  On the other hand, when the demodulator 50 receives the composite carrier signal from the modulator 20, the demodulator 50 starts the demodulation process at time t3. When the demodulation process is completed at time t5, the extracted verification message and transmission message are output to the processing unit 10.

  The processing unit 10 starts verification processing of the verification message output from the demodulation unit 50 at time t6. The collation process is completed in a short time. For example, the collation process is completed at time t7. And when a collation result is incompatibility, it controls to output a transmission stop control signal to transmission part 40, and to stop transmission to a rail.

  In FIG. 3, the verification message verification process is started at time t6 and the verification process is completed at time t7. However, time t7 is a time before time t10 when the transmission for one transmission message is completed. is there. That is, the verification message verification process is completed between the start of transmission of one transmission message (time t2) and the completion (time t10). The transmission of the transmission message itself can be terminated halfway.

  In the above description, the case where the processing unit 10 performs the verification process after the entire verification message has been demodulated by the demodulation process has been illustrated and described, but every time the demodulation unit 50 demodulates the verification message bit by bit, Collation may be performed on a bit basis. Regardless of which method is used for verification, the verification message verification process can be completed before the transmission unit 40 completes transmission of one transmission message.

  Although not shown in the drawing, the processing unit 10 also performs a collation process for a transmission message in addition to a collation process for a verification message. In this case, the processing unit 10 completes the transmission message collation processing after time t10, but the collation processing accuracy is improved by collating the transmission message itself. In addition, when the collation result is incompatibility, the processing unit 10 outputs a transmission stop control signal to the transmission unit 40 and controls to stop transmission of subsequent transmission messages.

3. Operational Effect According to the message transmission device 1, a transmission message is generated by the processing unit 10, and as a message uniquely corresponding to the transmission message, a certain generation rule based on the transmission message (according to the present embodiment). A verification message is generated according to (Replicate All). Then, the modulation unit 20 performs the first modulation process and the second modulation process, and generates a combined carrier signal obtained by combining the carrier component of the transmission message and the carrier component of the verification message. Then, the frequency band component of the transmission message included in the combined carrier signal is extracted by the transmission filter unit 30 and transmitted to the rail by the transmission unit 40.

  On the other hand, the combined carrier signal output from the modulation unit 20 is demodulated by the demodulation unit 50, and a transmission message and a verification message are extracted. Then, the processing unit 10 performs the second matching process for the verification message and the first matching process for the transmission message. Then, when either the collation result of the second collation process or the collation result of the first collation process is incompatible, the processing unit 10 performs control to stop transmission of the transmission message from the transmission unit 40.

  In this embodiment, the modulation processing is performed using a frequency higher than the frequency for transmitting a message as a verification frequency. As a result, the transmission speed of the verification message can be made larger than the transmission speed of the transmission message, and the demodulation processing for one verification message is completed before the transmission of one transmission message is completed. The collation process can be completed. Therefore, even if it is one message, it is possible to prevent an erroneous message from being adopted on the on-board device side and to ensure the safety of train operation.

  Further, since the verification message is the same message as the transmission message, it is possible to verify whether or not there is an error in the content of the transmission message by performing the verification message verification process. That is, when the verification message verification process is performed, whether or not the content included in the verification message is correct may be checked based on the train notification target information or the like. In that case, the verification message verification process can provide an effect as if the transmission message was verified.

  Furthermore, in this embodiment, not only the verification message verification process but also the transmission message verification process is performed, and when any of the verification results is incompatible, the transmission of the transmission message by the transmission unit 50 is stopped. . By performing transmission control by such a double verification process, it is possible to realize transmission of a message in accordance with the principle of fail-safe.

4). Modified example 4-1. Application System In the above-described embodiment, a telegram transmission device used for ATC, which is a kind of railway security system, has been described as an example. However, the transmission device to which the present invention is applicable is not limited to this. The present invention can be applied not only to a wired communication device to a wired cable but also to a wireless communication device. That is, the present invention can be applied to any system capable of transmitting a message on a carrier signal.

4-2. In the embodiment described above, both the verification message matching process and the transmission message matching process are executed. However, the transmission message matching process may be omitted. In this case, the demodulator 50 may be designed to demodulate only the verification message.

  In this case, a filter (verification filter unit 70) that cuts the frequency band component of the transmission message out of the combined carrier signal input to the demodulation unit 50, as in the message transmission device 2 in FIG. It may be inserted between 20 and the demodulator 50.

4-3. In the embodiment described above, the configuration has been described in which the processing unit 10 outputs a transmission stop control signal to the transmission unit 40, thereby suppressing transmission of the transmission message from the transmission unit 40. It is good also as a structure.

FIG. 5 is a block diagram showing a functional configuration of the telegram transmission apparatus 3 in this modification.
In the electronic message transmission device 3, a switch unit 80 is provided between the modulation unit 20 and the transmission filter unit 30. The switch unit 80 is normally closed (ON), and the combined carrier signal is output from the modulation unit 20 to the transmission filter unit 30. However, if the collation result of the electronic message is incompatible, a switch switching signal is output from the processing unit 10 to the switch unit 80, and the switch unit 80 is switched to an open state (OFF). As a result, the output of the combined carrier signal from the modulation unit 20 to the transmission filter unit 30 is blocked, and the transmission of the signal by the transmission unit 40 is stopped.

4-4. 2. Type of Verification Message In the above-described embodiment, as shown in FIG. 2, it has been described that the verification message is generated by duplicating the entire transmission message. However, a part of the transmission message is duplicated, A verification message including the message may be generated. For example, as shown in FIG. 6 (1), a verification message may be generated by duplicating a portion other than the header portion of a transmission message including a header portion, a data portion, and a check code portion.

  Further, a verification message may be generated including identification information for identifying the verification message. For example, as shown in FIG. 6 (2), a serial number part for storing a serial number for identifying a verification message is provided after the header part of the transmission message, and a serial number that is sequentially incremented every time a verification message is generated. A verification message may be generated by storing in the serial number part.

  By adding the identification information to the verification message, it is possible to detect even when the same message is repeatedly transmitted due to some failure. That is, depending on the failure, there may occur a failure in which the same message is repeatedly transmitted although originally a different message should be transmitted. Even in such a case, a change in the identification information attached to each verification message is monitored by the collation process. If the identification information does not change, it can be determined that an abnormality has occurred.

4-5. In the above-described embodiment, the verification message is described as being conveyed only once while one transmission message is being conveyed. That is, during the first modulation process for modulating the transmission telegram, the second modulation process for modulating the verification telegram is performed only once, thereby generating the composite carrier signal. Instead of such a configuration, while the transmission message is being modulated (first modulation processing), the second modulation processing may be repeated, and each of the modulated verification messages may be verified.

  FIG. 7 is a diagram showing the relationship between the transmission message and the verification message in this case, and the horizontal axis is the time axis. In FIG. 7, the verification message is repeatedly modulated by the modulation unit 20, so that the combined carrier signal becomes a signal carrying a plurality of verification messages while carrying one transmission message. Then, until the transmission of one transmission message is completed, the verification processing of each verification message is performed. In this case, it is possible to guarantee the normality of the apparatus during the entire transmission time for one transmission message.

4-6. In the embodiment described above, the MSK modulation method, which is a type of frequency shift key modulation method, has been described as performing a modulation process based on a transmission message and a verification message. However, other frequency shift modulation methods are used. May be used to perform modulation processing.

  Further, instead of using the frequency shift keying method, a phase shift keying method may be used, or a modulation method combining the frequency shift keying method and the phase shift keying method may be used. Regardless of which modulation method is used, it is possible to separate the frequency band of the verification message from the frequency band of the transmission message, and if the transmission rate of the verification message is greater than the transmission rate of the transmission message, the above-described implementation is performed. The same effect as the form can be obtained.

4-7. Selection of Carrier Frequency The modulation frequency selected in the above-described embodiment is an example, and the setting can be changed as appropriate. For example, the carrier frequency may be several kHz to 20 kHz, the bandwidth may be 100 Hz to several hundred Hz, and the frequency may be selected so that the verification frequency is higher than the message transmission frequency. In this case, it is more preferable to select the frequency so that the transmission speed of the transmission message is about several hundred bps and the transmission speed of the verification message is about 3 to 10 times this value.

4-8. Transmission of Telegram In the above-described embodiment, the transmission filter unit 30 is provided to cut the frequency band component of the verification telegram from the combined carrier signal output from the modulation unit 20. However, if there is no problem in train operation or the like regarding the transmission of the verification message to the rail, the transmission filter unit 30 may be omitted and the combined carrier signal may be transmitted to the rail as it is.

4-9. The processing unit has been described as performing the electronic message generation process and the electronic message collating process in one processing unit 10, but the first processing unit that performs the electronic message generation process and the second processing unit that performs the electronic message verification process. The two processing units may be provided so that each processing unit functions independently.

DESCRIPTION OF SYMBOLS 1 Message transmission apparatus 10 Processing part 12 Storage part 20 Modulation part 30 Transmission filter part 40 Transmission part 50 Demodulation part 60 Communication part 70 Verification filter part 80 Switch part

Claims (7)

A transmission message generation means for generating a transmission message;
Verification message generation means for generating a verification message corresponding to the transmission message according to a generation rule determined in advance based on the transmission message;
A transmission telegram carrier component obtained by modulating a signal of a predetermined message transmission frequency by a predetermined message modulation method based on the transmission message, and a signal of a predetermined verification frequency different from the message transmission frequency A modulation means for generating a combined carrier signal obtained by combining a verification message carrier wave component modulated by a predetermined modulation method for a verification message based on
Transmission message signal extraction means for extracting a signal of the message transmission frequency from the combined carrier signal generated by the modulation means;
An output means for externally outputting the signal extracted by the transmission message signal extraction means toward a predetermined transmission destination;
Demodulating means for obtaining a verification message carried by a verification message carrier component of the combined carrier signal by demodulating the combined carrier signal generated by the modulation means in a demodulation method corresponding to the verification message modulation method When,
Collating means for collating the verification message acquired by the demodulating means with the verification message generated by the verification message generating means;
A deterrence control unit that controls to suppress the external output when the collation result of the collation unit is incompatible;
A telegram transmission device comprising: The demodulation means demodulates the combined carrier signal generated by the modulation means in a demodulation method corresponding to the electronic message modulation method, so that the transmission message carried in the transmission message carrier component of the combined carrier signal is Get more,
The collation means further collates the transmission message acquired by the demodulation means and the transmission message generated by the transmission message generation means,
The suppression control unit performs control to suppress the external output when any of the verification result of the verification message by the verification unit and the verification result of the transmission message is incompatible.
The electronic message transmission apparatus according to claim 1. The modulation means performs the modulation using a frequency higher than the message transmission frequency as the verification frequency, and a carrier time length for one verification message in the verification message carrier component is in the transmission message carrier component. Generating the combined carrier signal shorter than the transmission time length of one transmission message;
3. The message transmission device according to claim 1, wherein the verification unit completes the verification for one verification message before the external output of the signal carrying the transmission message is completed. . The modulation means generates the composite carrier signal so as to repeatedly carry the verification message in the verification message carrier component while one transmission message is carried in the transmission message carrier component.
The electronic message transmission apparatus according to claim 3. The verification message generation unit generates the verification message including at least a copy of a part or all of the transmission message generated by the transmission message generation unit;
The telegram transmission apparatus according to any one of claims 1 to 4. The verification message generation means generates the verification message including identification information for identifying each verification message;
The telegram transmission apparatus according to any one of claims 1 to 5. A verification message generation step for generating a verification message corresponding to the transmission message according to a predetermined generation rule based on a given transmission message;
A transmission telegram carrier component obtained by modulating a signal of a predetermined message transmission frequency by a predetermined message modulation method based on the transmission message, and a signal of a predetermined verification frequency different from the message transmission frequency A combined carrier signal generation step for generating a combined carrier signal by combining a verification message carrier wave component modulated by a predetermined verification message modulation method based on
A transmission message signal extraction step for extracting a signal of the message transmission frequency from the generated combined carrier signal;
An output step of externally outputting the extracted signal toward a predetermined destination;
A demodulation step for acquiring a verification message carried in the synthesized carrier signal by demodulating the generated synthesized carrier signal in a demodulation method corresponding to the verification message modulation method;
A suppression control step for performing control to suppress the external output when the acquired verification message and the verification message generated in the verification message generation step are incompatible;
A message transmission method including

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