JP4969361B2 - GPS radio wave blocking object detection system - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS radio wave blocking object detection system that detects the presence or absence of a metal object such as a railway vehicle or an automobile, and other GPS radio wave blocking objects, and more specifically, a GPS for a satellite navigation system (Global Positioning System). (Global Positioning Satellite) The present invention relates to a method of configuring a GPS radio wave blocking object detection system that detects whether or not a detection target exists using GPS radio waves transmitted from a satellite in a fail-safe manner.

As a method for detecting a metal object including a rail vehicle, a rail circuit method for detecting the presence of the rail by short-circuiting the left and right rails on the vehicle axle is widely adopted (for example, patent documents). 1). In addition, a loop coil system using the fact that the transmission frequency changes due to the presence of a metal object (see, for example, Patent Document 2), and the light transmitted from the light emitter to the light receiver is blocked by the light shielding object. A photo-interrupter method for detecting the presence of the light has been put into practical use.
Moreover, as a detection system using GPS, a GPS antenna and a GPS receiver are mounted on a moving body such as a tram to detect an operation position (see, for example, Patent Document 3), a GPS antenna or the like is fixed to the ground. Among them are those that measure crustal deformation.

  Furthermore, the operation and security equipment for railway signals is required to have fail-safety in order to ensure the safety of railway transportation (for example, see Non-Patent Document 1). To express this fail-safety simply, "When a failure occurs in the operation and safety equipment, the entire system operates on the safe side due to the failure." The safety side in the railway signal is, for example, a stop signal in a traffic light (Red light) and the safety side can be clearly defined. The traffic signal is configured to automatically indicate a stop signal when a train is present when a train presence / absence result is given to a section for controlling the traffic signal from an apparatus / system for detecting the presence / absence of the train. Therefore, the fail-safety in a device / system that detects the presence / absence of a train is to output the state in which the train exists when the device / system diagnoses its own soundness and fails (for example, non-patent literature). 1).

  Currently, the most widely used device for detecting the presence or absence of a train is a track circuit, which uses a rail as an electric circuit, and when a train is present in a certain section, the axle shorts between the rails. It detects the presence of. As a track circuit for controlling a traffic light, a closed circuit type (closed loop type) is adopted from the viewpoint of fail-safety. A closed circuit type track circuit has a power supply connected to one end of the track circuit and a relay (track relay) connected to the other end, and constantly supplies a current for train detection from the power supply to the rail. The track relay is driven (excited) through the rail. When a train is present in this track circuit, the axles short-circuit between the rails to cut off the current for driving the relay, and the relay is de-energized (de-energized).

This non-excited state of the relay is a state where a train is present. For example, even when the rail breaks or the relay coil is broken, the relay is de-energized and the signal device is changed to a stop signal state. Therefore, safety can be ensured (see, for example, Non-Patent Document 2 and Non-Patent Document 3).
In addition, as an element that realizes fail-safety, relays that are asymmetric error elements have been realized for a long time, but in recent years, even in microcomputer systems using symmetrical error elements such as semiconductor parts, fail-safety has been achieved. Various systems to be realized have been put into practical use (see, for example, Patent Document 4).

JP 2000-168554 A Japanese Patent Laying-Open No. 2005-233883 Japanese Patent Laid-Open No. 2006-240478 JP 2003-146214 A Article 63 (Ensuring safety in the event of a failure) "Ministerial Ordinance Establishing Technical Standards for Railways" Article 59 (Devices for detecting trains, etc.) "Railway circuit (revised version)" P6-7, published by Japan Railway Electrical Engineering Association, issued on May 10, 1992

    [Prior Patent Application] Japanese Patent Application No. 2007-192333

By the way, since the detection system using GPS uses GPS radio waves that can be received free of charge, it is not necessary to provide a transmitter on its own, so that the cost can be reduced accordingly.
In addition, it can receive radio waves from multiple GPS satellites, and each radio wave contains multiple pieces of information such as time information and position information. By doing so, the accuracy and accuracy of object detection and response time can be specified.
However, the conventional GPS-based system measures the position but does not detect the presence or absence of an object.

On the other hand, a conventional object detection system that does not use GPS detects whether or not it can be received while transmitting radio waves or the like. For this reason, the presence or absence of an object can be determined according to whether or not the transmission signal is blocked by the detection target.
However, since not only the receiver but also the transmitter has to be provided on its own, the cost increases accordingly. In addition, in order to perform detection reliably, there is a need for a means for making the radio waves unique and discriminating between normal radio waves and noise by adding an ID (identification code) or modulating the radio waves to be transmitted and received. It is.
Therefore, focusing on the fact that metal objects such as railway vehicles and automobiles block GPS radio waves, a GPS radio wave blocking object detection system that detects metal and other GPS radio wave blocking objects by using GPS is simple and easy. It would be desirable to realize it at a low cost.

A metal object detection system that detects the presence or absence of a metal object such as a railway vehicle or automobile as a detection object, and the detection object is detected using GPS radio waves transmitted from a GPS satellite for a satellite navigation system. A metal object detection system (GPS radio wave blocking object detection system) that detects whether or not it exists has been proposed (see the above-mentioned prior patent application).
However, when such a metal object detection system is applied to a railway signal, as described above, the railway signal operation and security equipment is required to have fail-safety to ensure the safety of railway transportation. Fail-safety is also essential for a GPS radio wave blocking object detection system used in a field requiring equivalent safety.

  However, in the proposed metal object detection system (prior patent application), the presence or absence of a detection target can be detected, but this system does not have fail-safety. That is, since this GPS radio wave blocking object detection system (prior patent application) utilizes the fact that GPS radio waves are constantly emitted from GPS satellites, the GPS radio wave blocking object is detected depending on the presence or absence of this radio wave (radio wave intensity and information). The basic requirements necessary to realize fail-safety by the closed circuit type (closed loop type) configuration as well as the closed circuit type track circuit of the railway signal are provided. The function of making a transition to the safe side against a failure of the device itself is not guaranteed, and it has not been made fail-safe.

For example, in the case of detecting the presence or absence of a car in a general parking lot, even if this system breaks down and the determination of presence or absence is different depending on the actual presence or absence, it will not be a serious situation related to human safety, Since system failures will be tolerated, even existing systems can be put to practical use. On the other hand, when this metal object detection system is applied to the railway signal field to detect the presence or absence of a train, this system is made to be a fail-safe configuration. It is indispensable to ensure the safety of railway transportation by outputting.
Therefore, when a metal object detection system using GPS radio waves is applied to a railway signal field or a field requiring similar safety, it is a technical problem to provide the system with fail-safety.

The GPS radio wave blocking object detection system of the present invention (Solution 1) was created to solve such problems, and was obtained via a GPS antenna for receiving GPS radio waves and this antenna. A GPS receiver that processes the GPS signal and outputs a positioning result, and determines whether or not the radio wave reception is successful based on the output of the receiver, and determines that no GPS radio wave blocking object exists when the radio wave reception is successful. A GPS radio wave blocking object detection system including a determination device that determines that a GPS radio wave blocking object is present when reception is failed, wherein the determination device includes a fail-safe device, and the GPS antenna transmits the GPS The GPS ground device that reaches the determination device via the receiver and the soundness of the transmission system based on the output of the GPS receiver By monitoring the overall system is characterized that it is what failsafe.
Note that the GPS antenna, the GPS receiver, and the determination device may be individually mounted or integrally mounted. The GPS radio wave blocking object is typically a metal object, but is not limited to pure metal, and any object that can block GPS radio waves may be combined with other materials. It may be good, mixed, or made of non-metal.

  Further, the GPS radio wave blocking object detection system of the present invention (solution means 2) is the GPS radio wave blocking object detection system of the above solution means 1, wherein the determination device stores the installation position of the GPS antenna in advance. The storage position and the positioning result of the GPS receiver are compared in light of positioning accuracy, and when the two positions match, it is determined that the GPS ground device and its transmission system are healthy, and the GPS receiver While the determination result based on the success or failure of the radio wave reception of the GPS receiver is maintained, the GPS ground device and its transmission system are determined to be unhealthy when the two positions do not match, and the determination based on the success or failure of the radio wave reception of the GPS receiver Regardless of the result, it is characterized in that a safe determination is made that a GPS radio wave blocking object exists.

  Further, the GPS radio wave blocking object detection system of the present invention is (Solution means 3), the GPS radio wave blocking object detection system of the above solution means 2, wherein the GPS receiver processes a GPS signal obtained via the antenna. The time information is also output, and the determination device monitors the time included in the output of the GPS receiver. When the time is correctly updated, the GPS ground device and its transmission are transmitted. While judging that the system is healthy and maintaining the judgment result based on the comparison of the two positions, when the time is not correctly updated, the GPS ground device and its transmission system are judged to be unhealthy The present invention is characterized in that a safe determination is made that a GPS radio wave blocking object exists regardless of a determination result based on the comparison of both positions.

  Further, the GPS radio wave blocking object detection system of the present invention (Solution means 4) is the GPS radio wave blocking object detection system of the above solution means 1 to 3, wherein two sets of the GPS antenna and the GPS receiver are provided. Both antennas are arranged away from the moving direction of the GPS radio wave blocking object and facing the moving path, and the determination device determines whether or not the radio wave reception is successful based on the output of the GPS receiver. When both radio waves are successfully received, it is determined that no GPS radio wave blocking object exists, and when one radio wave reception fails, it is determined that a GPS radio wave blocking object exists. The determination result based on this is transited to the safe side.

  Further, the GPS radio wave blocking object detection system of the present invention (Solution means 5) is the GPS radio wave blocking object detection system of the above solution means 4, wherein the determination device measures the positioning results of the two sets of GPS receivers. Compared to the accuracy and the separation distance of the two antennas, when the two positions match, it is determined that the GPS ground device and its transmission system are healthy, and the determination is based on the success or failure of radio reception by the GPS receiver. While maintaining the result, when the two positions do not match, the GPS ground device and its transmission system are judged to be unhealthy, and the GPS radio wave blocking object is determined regardless of the result of the radio wave reception of the GPS receiver. It is characterized by the fact that the safety side is judged to exist.

  Further, the GPS radio wave blocking object detection system of the present invention (solution 6) is the GPS radio wave blocking object detection system of the above solution 5, and both of the GPS receivers are obtained via the antenna. The GPS signal is processed and time information is also output. The determination device compares the time included in the outputs of the two GPS receivers in light of the measurement accuracy. When they match, it is determined that the GPS ground device and its transmission system are healthy and the determination result based on the comparison of the two positions is maintained, whereas when the two times do not match, the GPS ground device and its transmission system are not connected. It is judged to be healthy, and a safety side judgment is made that a GPS radio wave blocking object is present regardless of the judgment result based on the comparison between the two positions. .

  Further, the GPS radio wave blocking object detection system of the present invention is (the solution means 7), the GPS radio wave blocking object detection system of the above solution means 4 to 6, wherein the GPS radio wave blocking object to be detected is a train and the movement path Corresponding to the track for traveling the train, the separation distance of the two antennas is shorter than the minimum length of each vehicle of the train traveling on the track, and the separation distance of the both antennas of the train traveling on the track It is longer than the maximum length of the vehicle connecting portion.

  In such a GPS radio wave blocking object detection system of the present invention (Solution 1), instead of mounting the GPS antenna on the GPS radio wave blocking object to be detected, the GPS radio wave is directed toward a place where it is desired to detect the GPS radio wave blocking object. Install the antenna. In addition, when the GPS radio wave blocking object is present at the detection target position, the GPS radio wave to the GPS antenna is blocked by the installation. However, if there is no GPS radio wave blocking object at the detection target position, the GPS radio wave is GPS. Make sure it reaches the antenna. If it does so, determination of a determination apparatus will be performed according to the presence or absence of the arrival of the GPS radio wave to the GPS antenna, and the presence or absence of the GPS radio wave blocking object is detected. In this way, by removing the GPS antenna from the object to be detected and determining whether or not there is a GPS radio wave blocking object depending on whether GPS radio waves can be received or not, the facility for transmitting radio waves can be installed on its own. Since the presence / absence of an object can be detected even if it is not provided, the configuration is simplified and the cost is reduced as much as unnecessary transmission equipment.

  GPS (Global Positioning System) is a system that calculates the position (latitude / longitude / altitude) of a receiver using radio waves transmitted by artificial satellites. The price is very cheap. The present invention applies a widely spread and stable GPS to a detection system for the presence of a GPS radio wave blocking object instead of the original positioning, and detects that a GPS radio wave from an artificial satellite is blocked by the GPS radio wave blocking object. By detecting the presence / absence, the advantages of the conventional object detection system and the GPS utilization system are combined.

Specifically, since the GPS antenna and the GPS receiver can be installed outside the detection target while using the GPS, the installation and maintenance are easy and the convenience is excellent.
In addition to receiving radio waves from multiple GPS satellites, each radio wave contains unique information such as time information and position information. Regular radio waves and noise can be discriminated.
Therefore, according to the present invention, first, a GPS radio wave blocking object detection system can be realized simply and inexpensively.

  Moreover, in the present invention, in addition to that, the determination device for determining the presence or absence of a GPS radio wave blocking object is configured by a fail-safe device such as a fail-safe microcomputer, and the determination device is made fail-safe. Thus, the soundness of the GPS ground device and its transmission system (GPS antenna and GPS receiver, and transmission system from the GPS antenna to the determination device) is monitored by the fail-safe determination device based on the output of the GPS receiver. As a result, a system including a GPS antenna or a GPS receiver that does not have fail-safe properties as a single unit is provided with fail-safe properties in the entire system.

  GPS is widely used as a positioning system by nature, and is provided at low cost due to its versatility. The GPS radio wave blocking object detection system applies this GPS to the presence or absence of a radio wave blocking object, but there are various uses and purposes of use. For example, it may be used to issue an alarm when an object is taken away, or it may be used to issue an alarm when an object enters a certain space. The purpose of use is different depending on whether priority is given to the detection of the object or the detection of the absence of the object.

  Further, whether or not high safety is required for the GPS radio wave blocking object detection system also depends on the application. For example, when detecting the presence or absence of a car in a general parking lot, safety will not be required, and lower cost than safety will be required. In this case, the versatility of the current GPS should be maintained. On the other hand, when this GPS radio wave blocking object system is applied to the railway signal field and the presence / absence of a train is detected, fail-safety is essential for this system. In this case, safety is given priority over price.

While the priority or safety of the detection state (presence / absence) required for this GPS radio wave blocking object detection system differs depending on the use and purpose of use, the present invention provides a GPS ground device itself including a GPS antenna and a GPS receiver. Without changing the basic hardware and software specifications, the specifications of the judgment device connected to the GPS receiver realize fail-safety according to the application, and maintain the versatility of GPS. Therefore, it is possible to provide a fail-safe property depending on the application while maintaining low cost and follow-up to technological progress.
Therefore, according to the present invention, a simple and inexpensive GPS radio wave blocking object detection system using GPS radio waves can be provided with fail-safety, and the application of the GPS radio wave blocking object detection system to the railway signal field or the like can be achieved. Can be realized.

In the GPS radio wave blocking object detection system according to the present invention (solution 2), the fail-safe determination device receives information on the position (for example, longitude and latitude) as a result of the arithmetic processing of the GPS receiver. The received positioning result is compared with the storage position that is information of the antenna installation position (for example, longitude and latitude) that is stored in advance in the determination device, and monitoring that both positions match. By determining that the GPS ground device and its transmission system (device and transmission between the GPS antenna and the determination device) are sound, general-purpose products that do not have fail-safety are adopted for the GPS antenna and GPS receiver. Even so, the entire system becomes failsafe.
As a result, the GPS ground device including the GPS antenna and the GPS receiver maintains versatility, that is, the entire system is configured to be fail-safe while maintaining the low cost of the GPS ground device and the ability to follow technological progress. Can do.

  Furthermore, in the GPS radio wave blocking object detection system of the present invention (solution 3), when the fail-safe determination device monitors the soundness of the GPS ground device and its transmission system, in addition to the position comparison, By determining whether or not to update the time, the soundness judgment becomes more strict, and the fail-safeness is further improved.

  In the GPS radio wave blocking object detection system according to the present invention (solution 4), two sets of GPS antennas are installed apart along the direction in which the GPS radio wave blocking object moves. Only when the signal can be received, the processing at the time of successful radio wave reception is performed, so that the fail-safe property is enhanced. Also, even if the GPS radio wave blocking object has a chip or the like, if it is shorter than the separation distance of both antennas, the GPS radio wave that has passed through the chip and the like will not be received simultaneously by both antennas. Since the detection accuracy is improved, the fail-safe property is enhanced from this viewpoint.

  Further, in the GPS radio wave blocking object detection system of the present invention (solution 5), the position (for example, longitude) that is the result of each GPS receiver processing the two GPS signals received by the two sets of GPS antennas. And the latitude) are checked by a fail-safe determination device, and the GPS ground device between the GPS antenna and the determination device and its transmission system are determined to be healthy by monitoring that these two positions match. As a result, even if a general-purpose product that does not have fail-safe properties is adopted for the GPS antenna or the GPS receiver, or there are a plurality of GPS ground devices, the entire system becomes fail-safe. Moreover, this soundness monitoring method can replace the method of the above solution 2 or be used in combination therewith.

  In the GPS radio wave blocking object detection system according to the present invention (solution 6), when the fail-safe determination device monitors the soundness of the GPS ground device and its transmission system, it compares two positions. In addition, since the two sets of times are also compared, the soundness judgment becomes more strict, so that the fail-safe property is further enhanced. Moreover, this soundness monitoring method can replace the method of the above solution 3 or can be used in combination therewith.

  In the GPS radio wave blocking object detection system of the present invention (Solution means 7), two sets of antennas are installed facing the track for train travel, and the distance between both antennas is set for each train vehicle. Due to being shorter than the minimum length and longer than the maximum length of the train vehicle connection part, the detection state of “with train” may be undesirably interrupted even in a train in which a plurality of vehicles are connected or in a connection part existing in the middle of the train. No. Therefore, the train can be detected accurately.

  Several modes suitable for implementing such a GPS radio wave blocking object detection system of the present invention will be described.

  The GPS radio wave blocking object detection system according to the first embodiment is a GPS radio wave blocking object detection system for each of the above-described solutions, and includes a radio wave reflector that reflects GPS radio waves, and the radio wave reflector and the GPS antenna. Are opposed to both sides of the movement path of the GPS radio wave blocking object, and when the GPS radio wave blocking object arrives, the GPS radio wave from the radio wave reflector to the GPS antenna is blocked, and when the GPS radio wave blocking object leaves, A GPS radio wave can reach the GPS antenna from a radio wave reflector.

  In the first embodiment, after introducing a radio wave reflector, the GPS antenna and the GPS antenna are arranged opposite to both sides of the movement path of the GPS radio wave blocking object, and reach the GPS antenna via the radio wave reflector. Since the GPS radio wave is blocked only when the GPS radio wave blocking object arrives, the detection of the moving body by the simple and inexpensive system using GPS can be detected from outside the moving body and from the outside of the moving path. You can do it. Therefore, the present invention can be applied not only to a moving body but also to environments and facilities where it is not desired to install a GPS antenna or the like on a moving path. In addition, since the radio wave reflector can be prepared easily and inexpensively from the transmission equipment that emits radio waves, the advantage of realizing the GPS radio wave blocking object detection system easily and inexpensively can be inherited without loss.

  A GPS radio wave blocking object detection system according to the second embodiment is the GPS radio wave blocking object detection system according to the first embodiment described above, and shields GPS radio waves from the sky to the GPS antenna, but from the radio wave reflector. A radio wave shielding body that does not shield GPS radio waves to the GPS antenna is provided.

  In the second embodiment, by providing a specific radio wave shield, it is possible to avoid reception of undesired GPS radio waves from the sky without the GPS antenna being directed downward or obliquely downward. Can be received. Therefore, the installation conditions of the radio wave reflector and the GPS antenna are alleviated, and the convenience is further improved. Moreover, the radio wave shield can be prepared more easily and cheaply than the radio wave reflector, and even if the radio wave shield and the radio wave reflector are used in combination, the radio wave shield is simpler and less expensive than having its own transmission equipment. The advantage of simply and inexpensively realizing the radio wave blocking object detection system is also inherited.

With regard to such a GPS radio wave blocking object detection system of the present invention, specific modes for carrying out this will be described with reference to the following first to third embodiments.
The embodiment 1 shown in FIGS. 1 and 2 embodies the above-described solving means 1 to 3 (claims 1 to 3 as originally filed), and the embodiment 2 shown in FIG. Means 4 to 7 (claims 4 to 7 as originally filed) are embodied, and Example 3 shown in FIG. 4 embodies Embodiments 1 and 2 described above, both of which are trains. It is an example of application to a detection system.

  A specific configuration of the train detection system 10 that is Embodiment 1 of the GPS radio wave blocking object detection system of the present invention will be described with reference to the drawings. 1A is a perspective view of the train detection system 10, FIG. 1B is a functional block diagram of the determination device 13, and FIG. 1C is a flowchart of determination processing of the determination processing unit 13b.

The train detection system 10 (see FIG. 1A) includes a GPS antenna 11, a GPS receiver 12, and a determination device 13. The determination device 13 is provided with an output relay 13a for sending a detection result to a higher station device or an interlocking device.
The GPS antenna 11 may be a commercially available general-purpose product as long as it can receive GPS radio waves transmitted from GPS satellites, and the mounting form is arbitrary such as a film form or a plate form.
The GPS receiver 12 is connected to the GPS antenna 11 by a coaxial cable, a BNC connector, or the like, and is a commercially available general-purpose product as long as it processes a GPS signal obtained through the GPS antenna 11 and outputs a positioning result. It ’s enough. The output S generally includes time information and position information, but it is easy to use a receiver that outputs a GPS radio wave reception level as a numerical value or a logical value.

The determination device 13 is a logical operation unit mainly composed of, for example, a microprocessor or a digital signal processor, but is constituted by a fail-safe device such as a fail-safe microcomputer.
Various methods are known for realizing fail-safe devices (see, for example, Patent Document 4). Here, when a failure is diagnosed with a self-diagnosis function, the output is shifted to the safe side. Any specific method may be used.

  In this fail-safe determination device 13 (see FIG. 1B), a “fail-safe computer” that performs self-diagnosis by a known method and tries to control the output relay 13a to be non-excited at the time of failure and to be excited at the normal time. In addition to a later-described determination processing unit 13b that performs processing corresponding to train detection for application purposes, the outputs of both processing units are integrated into the relay control R to provide an output relay 13a. In order to maintain the fail-safe property during the integration, if there is any one that is to be controlled to be non-excited, the output relay 13a is only turned on when the output relay 13a is de-energized and all are controlled to be excited. An “output relay controller” for excitation is also provided.

  The determination processing unit 13b (see FIG. 1C) collectively performs the determination of the presence / absence of a train and the soundness diagnosis processing of the GPS receiver 12, and performs radio wave reception based on the output S of the GPS receiver 12. After determining success / failure, specifically, the presence / absence of radio wave reception is determined according to the reception level of GPS radio waves, and when radio wave reception is successful, it is determined that there is no train (no GPS radio wave blocking object is present). Attempting to excite the output relay 13a, when radio wave reception fails, it is determined that there is a train (a GPS radio wave blocking object is present) and the output relay 13a is to be de-excited. More specifically, the output S of the GPS receiver 12 is input as needed, and the success or failure of radio wave reception is determined based on the output S. The success / failure determination is based on the reception of GPS radio waves at the output S of the GPS receiver 12. If the level includes a logical value indicating whether it is correct or not, the logical value is used as it is. If the reception level is a numerical value, the level is binarized with an appropriate threshold.

  Although not shown in the figure, the determination processing unit 13b has the following function expansion using the fact that there are a plurality of GPS satellites and each GPS radio wave includes time information and position information. That is, in the train detection system 10 of a railway that detects a train (a metal object, a moving object, a GPS radio wave blocking object), it is desired to preferentially detect the presence of a train for ensuring safety. If one of the GPS signals received from a plurality of (for example, three) GPS satellites is interrupted, it is determined that there is a train (there is a train), and conversely all three It is determined whether there is GPS signal reception from and whether the time information and position information included therein are appropriate, and it is also determined that there is no train (no train exists) only when it is valid It has become.

  Furthermore, the determination device 13 can store the antenna installation position in advance by, for example, latitude and longitude by manual setting or automatic measurement setting when the GPS antenna 11 is installed by an initialization processing unit (not shown), The determination processing unit 13b can refer to this storage position. Then, the determination processing unit 13b (see FIG. 1C) illuminates the positioning result of the GPS receiver 12 included in the output S of the GPS receiver 12 as position information and the above-described storage position with respect to the positioning accuracy. In comparison, when the two positions coincide with each other, it is determined that the GPS ground device from the GPS antenna 11 to the determination device 13 and its transmission system are sound, and the determination result is based on the success or failure of radio reception by the GPS receiver 12 described above. Is supposed to maintain.

  On the other hand, when both positions, that is, when the positioning result and the storage position do not match, the determination processing unit 13b determines that the GPS ground device including the GPS receiver 12 and its transmission system are unhealthy, and receives the GPS signal. Regardless of the result of determination based on the success or failure of radio wave reception by the machine 12, a safety-side determination is made that “there is a train” (a GPS radio wave blocking object is present). The positioning accuracy of the GPS receiver 12 can be expected to be higher if it is fixed on the ground side rather than being mounted on a moving body, and can be further improved by adding differential positioning or statistical methods. However, since there is a limit anyway, if the difference between both positions is within or slightly exceeding the limit, it is determined that both positions match.

  Further, (see FIG. 1C), the determination processing unit 13b holds the time information included in the output S of the GPS receiver 12 for a certain period of time, and the progress of the time. By monitoring this, when the determination device 13 has a built-in clock, the time of the built-in clock is also checked to determine whether the time update is appropriate for the time obtained from the GPS radio wave. Yes. For example, the time obtained from GPS radio waves does not advance, the order of input from the GPS radio waves is reversed, or the time obtained from GPS radio waves differs greatly from the time on the built-in clock. If there is no such abnormality, it is determined that the time has not been updated correctly.

When the time is properly updated, it is determined that the GPS ground device including the GPS receiver 12 and its transmission system are healthy, and the determination result based on the comparison between the positioning result and the storage position is maintained. To do. On the other hand, when the time is not correctly updated, it is determined that the GPS ground device including the GPS receiver 12 and its transmission system are unhealthy, and regardless of the determination result based on the comparison of both positions, A safety judgment is made that “there is a train” (a GPS radio wave blocking object exists).
The output relay 13a (see FIG. 1A) is controlled by the determination device 13 and is excited or not excited by the relay control R from the determination device 13. The excitation state is “no train”, that is, “ Corresponding to “a state where there is no GPS radio wave blocking object”, a non-excited state corresponds to “a train is present”, that is, “a state where a GPS radio wave blocking object is present”.

  With respect to the train detection system 10 (GPS radio wave blocking object detection system) of the first embodiment, its usage and operation will be described with reference to the drawings. FIG. 2 is a perspective view of an installation location showing the usage state.

  When the train detection system 10 is installed to detect a train 15 (metal object, moving object, GPS radio wave blocking object) traveling on the rail 14 (track, moving route), the GPS antenna 11 passes above the train 15. It is installed between the rails 14 and 14 (on the track and on the moving route) with the radio wave reception direction facing upward. However, the GPS receiver 12 and the judgment device 13 are installed in an easy place for maintenance work because there are no special restrictions. Good. The GPS radio wave 17 is received from the GPS satellite 16 in the sky and the GPS radio wave 17 is received by the GPS antenna 11 if there is nothing to block it.

When the train detection system 10 operates without any abnormality, the GPS radio wave 17 reaches the GPS antenna 11 until the train 15 enters. Therefore, the GPS radio wave 17 is successfully received based on the output S of the GPS receiver 12. In response to this, the determination device 13 determines “no train” and the corresponding relay control R is issued.
On the other hand, when the train 15 arrives, the GPS radio wave 17 is blocked by the train 15 and does not reach the GPS antenna 11, so that based on the output S of the GPS receiver 12, The determination device 13 determines that “there is a train”, and the corresponding relay control R is issued.

Further, when the train 15 runs away, the GPS radio wave 17 reaches the antenna 11 again, so that the determination device 13 determines “no train” in response to the successful reception, and the corresponding relay control R is issued. It is.
Thus, in the train detection system 10, if there is no abnormality in the GPS antenna 11, the GPS receiver 12, the determination device 13, and the signal cable connecting them, the train 15 (moving body) comes and goes as needed. It is detected accurately.

  By the way, in the train detection system 10, since the determination device 13 is a fail-safe device, if the determination device 13 breaks down while the train detection system 10 is in operation, this is the “fail-safe computer of the determination device 13. The output relay 13a is controlled to be non-excited so as to be detected by the “health diagnosis processing unit” and to force the train detection state to be “with train” on the safe side. In addition, a serious abnormality occurred at any one of the GPS antenna 11, the GPS receiver 12, the signal cable connecting them, and the signal cable connecting the GPS receiver 12 and the determination device 13. In this case, any or all of the GPS radio wave reception level, time information, and position information included in the output S of the GPS receiver 12 indicate an abnormal value, which is the determination processing unit 13b of the determination device 13, that is, The output relay 13a is controlled to be non-excited so as to be detected by the “train presence / absence determination and GPS receiver soundness diagnosis processing” unit and to force the train detection state to be “with train” on the safe side.

  As described above, in the train detection system 10, even when the determination device 13 itself including a fail-safe microcomputer or the like fails, the GPS ground device and its transmission system (the GPS including the GPS antenna 11 and the GPS receiver 12). Since the output relay 13a is controlled to be non-excited even when an abnormality occurs anywhere in the transmission system from the GPS antenna 11 through the GPS receiver 12 to the determination device 13), the GPS radio wave This indicates a state in which the train 15 that is a blocking object is present, and the system state transitions to a safe side such that a railway traffic signal is used as a stop signal, so that safety can be ensured.

  A specific configuration of the train detection system 20 that is the second embodiment of the GPS radio wave blocking object detection system of the present invention will be described with reference to the drawings. 3A is a perspective view of the train detection system 20, FIG. 3B is a flowchart of determination processing of the determination processing unit 13 b, and FIG. 3C is a plan view of locations where the GPS antennas 11 and 21 are arranged.

  This train detection system 20 is different from the train detection system 10 of the first embodiment described above in that a GPS antenna 21 and a GPS receiver 22 similar to the GPS antenna 11 and the GPS receiver 12 are added, and the GPS antenna and the GPS antenna are added. In addition to the two sets of receivers (see FIG. 3A), the determination device 13 is a determination device 23 that inputs the output S2 of the GPS receiver 22 in addition to the output S of the GPS receiver 12. (Refer to FIG. 3A), the determination device 23 is modified by remodeling the “train existence determination and GPS receiver soundness diagnosis processing” portion corresponding to the determination processing unit 13b of the determination device 13. This is a point 23b (see FIG. 3B).

  The determination device 23 receives the output S2 of the GPS receiver 22 (see FIG. 3A), and a determination processing unit 23b is provided instead of the determination processing unit 13b (see FIG. 3). 3 (b)), manual setting and automatic measurement on the premise that both antennas 11 and 12 are arranged facing the rail 14 with a separation distance L in the moving direction of the train (see FIG. 3 (c)). The determination device 13 may be the same as that of the determination device 13 except that the separation distance L is stored in advance by setting, and is configured by a fail-safe device.

  The determination processing unit 23b (see FIG. 3 (b)) determines whether or not radio wave reception has succeeded based on the radio wave reception levels included in the outputs S and S2 of the two sets of GPS receivers 12 and 22. In both cases, when the radio wave reception is successful, it is determined that there is no train (no GPS radio wave blocking object is present). On the other hand, when even one set of radio wave reception is unsuccessful, there is a train (having a GPS radio wave blocking object exists) ). Thereby, the determination apparatus 23 changes the determination result based on the success or failure of the radio wave reception of the GPS receiver to the safe side.

  Further, the determination processing unit 23b compares the position information (positioning result) included in the outputs S and S2 of the two sets of GPS receivers 12 and 22 with reference to the positioning accuracy and the separation distance L between the antennas 11 and 21. When the two positions (positioning results S and S2) coincide with each other, it is determined that the GPS ground device including the GPS receivers 12 and 22 and its transmission system are sound, and the radio waves of the GPS receivers 12 and 22 are obtained. The determination result based on the success or failure of reception is maintained. On the other hand, if the two positions (positioning results S and S2) do not match, it is determined that the GPS ground device including the GPS receivers 12 and 22 and some of their transmission systems are unhealthy, and the GPS receivers 12 and 22 Regardless of the result of the determination based on the success or failure of the radio wave reception, a safety determination is made that “there is a train”. The coincidence / non-coincidence of both positions is determined by whether or not the difference between the distance between both positions and the separation distance L is within an allowable range based on the positioning accuracy of the GPS receiver described above. Yes.

  Further, the determination processing unit 23b compares the times indicated by the time information included in the outputs S and S2 of the two sets of GPS receivers 12 and 22 in light of measurement accuracy, and compares both times (time S: time S2). ) Match, it is determined that the GPS ground device including the GPS receivers 12 and 22 and its transmission system are healthy, and the determination result based on the comparison of both positions (positioning results S and S2) is maintained. It has become. On the other hand, when both times (time S: time S2) do not match, it is determined that the GPS ground device including the GPS receivers 12 and 22 and its transmission system are unhealthy, and both positions (positioning results S and S2) Regardless of the result of the determination based on the comparison of the above, a safety-side determination is made that “there is a train”. Note that the measurement accuracy of the time to be taken into account includes a difference caused by a phase shift between the periods of the outputs S and S2 of the two sets of GPS receivers 12 and 22.

  Although not shown again, the determination processing unit 23b compares the positioning result related to the output S of the GPS receiver 12 with the storage position, and the GPS receiver 12 similarly to the above-described processing of the determination processing unit 13b. The appropriateness determination of the time update related to the output S of the GPS receiver 22, the comparison between the positioning result related to the output S2 of the GPS receiver 22 and the storage position, and the appropriateness determination of the time update related to the output S2 of the GPS receiver 22 are also performed. In either case, the determination result is shifted to the safe side.

  The use mode and operation of the train detection system 20 (GPS radio wave blocking object detection system) of the second embodiment will be described with reference to the drawings. FIG. 3C is a plan view of a location where the GPS antennas 11 and 21 are disposed.

When installing the train detection system 20, the GPS antenna 11, the GPS receiver 12, and the determination device 13 may be installed in the same manner as the train detection system 10 with respect to the rail 14 on which the train travels. The GPS antenna 21 may be installed in the same manner as the GPS receiver 12, but the GPS antenna 21 is installed upward in the radio wave receiving direction between the rails 14 and 14 and separated from the GPS antenna 11 by a separation distance L.
The separation distance L is determined in accordance with the train specifications for each railway line.

  Specifically, the separation distance L is shorter than the minimum length of each vehicle of the train traveling on the antenna installation destination track and longer than the maximum length of the vehicle connecting portion of the train traveling on the antenna installation destination track. There is a requirement that For example, in the Yamanote Line and Keihin Tohoku Line vehicles, the minimum vehicle length is 20 m, and the maximum connection length is 0.5 m. In addition, in the Tohoku / Joetsu Shinkansen vehicles, the minimum vehicle length is 25 m, and the maximum connection length is 0.5 m. Therefore, if the separation distance L is set to about 2 m, for example, it is suitable for most routes.

Then, when the train detection system 20 installed in this way is in operation, a detailed description that will be repeated is omitted, but basically there is no abnormality anywhere in the train detection system 20 as in the train detection system 10. For example, if the train is detected from time to time, if an abnormality occurs somewhere in the train detection system 20, the output relay 13a is controlled to be non-excited, and the detection state is forced to "safe" on the safe side. .
Of course, the number of GPS antennas and GPS receivers has increased to two, and the train detection capability and fail-safety are enhanced.

  That is, in the train detection system 20, when two sets of GPS antennas 11 and 21 are installed apart from each other by a separation distance L in the train moving direction, GPS signals can be received by both the antennas 11 and 21. Since the process at the time of successful radio wave reception is performed only in this case, the fail-safe property is enhanced. In addition, a train in which a plurality of vehicles are connected is dotted with connection portions that are insufficient or almost lacking in the ability to block GPS radio waves. The width of this connection portion is larger than the distance L between the antennas 11 and 21. Since the length of each vehicle is longer than the separation distance L of both antennas 11 and 21, GPS radio waves passing through the connecting portion are received simultaneously by both antennas 11 and 21. Since there is nothing, the detection accuracy is improved.

  Further, in the train detection system 20, each GPS receiver 12 and 22 performs calculation processing on the two GPS signals received by the two sets of GPS antennas 11 and 21, and the respective position information (positioning position S, When S2) is collated by the fail-safe determination device 23, in addition to the comparison between each position information and each storage position, a comparison is made as to whether or not both positions (positioning position S: positioning position S2) match. Since the GPS ground device and its transmission system between the GPS antennas 11 and 21 and the determination device 23 are strictly determined, the fail-safe property is high.

  Furthermore, in the train detection system 20, in addition to the above-described position comparison, the time comparison is also strengthened when monitoring the health of the GPS ground device and its transmission system by the fail-safe determination device 23. . That is, by using the fact that two sets of time information (time S, S2) are obtained, it is determined whether or not the time update is appropriate for one set of time information (time S), and another set of time information (time S2). ) Is also determined as to whether or not the time update is appropriate, and further, a comparison is made as to whether or not the two times (time S: time S2) match, and the GPS ground between the GPS antennas 11 and 21 and the determination device 23 is also compared. Since the judgment that the device and its transmission system are healthy is made more strictly, the fail-safe property is further enhanced.

A specific configuration of the train detection system 30 that is the third embodiment of the GPS radio wave blocking object detection system of the present invention will be described with reference to the drawings. FIG. 4A is a perspective view of the train detection system 30.
This train detection system 30 is different from the train detection system 10 of the first embodiment described above in that a radio wave reflector 31 and a radio wave shield 32 are added.

  The radio wave reflector 31 reflects a GPS radio wave sent to the ground from an overlying GPS satellite, and a radio wave reflector 31 that can send a reflected wave horizontally or obliquely upward is easy to use. A low-cost metal flat plate may be used, but if it is desired to focus GPS radio waves, a concave plate like a parabolic antenna may be used. Since this is installed separately from the main bodies 11-13, it is preferable to equip with the support | pillar which can adjust height or angle-of-attack adjustment.

  The radio wave shield 32 shields GPS radio waves flying downward from the sky to the GPS antenna 11, while not blocking GPS radio waves flying sideways from the radio wave reflector 31 disposed opposite to the GPS antenna 11. 11 is composed of a metal plate covering the upper part of 11 and its support part. However, if it is desired to shield an undesired reflected wave from the other, a metal box having an opening only on the radio wave reflector 31 side may be adopted.

  About the train detection system 30 of this Example 3, the use aspect and operation | movement are demonstrated using drawing. FIG. 4 shows the state of the track on which the train detection system 30 is installed, where (b) is a plan view and (c) is a front view.

When the train detection system 30 is installed to detect the train 15 traveling on the rail 14, the GPS antenna 11, the radio wave reflector 31, and the radio wave shield 32 are arranged on both sides of the rail 14. Since the determination device 13 and the radio device 33 are not specially restricted, they may be installed at a place where maintenance work is easy.
The GPS antenna 11 and the radio wave reflector 31 are arranged on both sides of the rail 14 so as to face each other. The radio wave shield 32 is provided in a place covering at least the upper part of the GPS antenna 11. The installation height of the GPS antenna 11 and the radio wave reflector 31 is set above the rail 14 and between the bottom and the ceiling of the train 15 and avoiding windows.

After the installation, the GPS radio wave 17 that has come directly from the sky is always blocked by the radio wave shield 32 and is not received by the GPS antenna 11 regardless of the operating state of the train detection system 30.
When the train detection system 30 is activated, until the train 15 enters, the GPS radio wave 17 that has come down from the sky and hits the radio wave reflector 31 is reflected there and turns sideways, and the GPS antenna 11 To reach. Also, in response to the successful reception, the determination device 13 determines “no train”, and the corresponding relay control R is issued.

On the other hand, since the GPS radio wave 17 from the radio wave reflector 31 to the GPS antenna 11 is blocked when the train 15 arrives, the determination device 13 determines “has a train” in response to the reception failure of the GPS radio wave 17. Then, a relay control R corresponding to that is issued.
Furthermore, since the GPS radio wave 17 arrives again from the radio wave reflector 31 to the GPS antenna 11 when the train 15 runs away, the determination device 13 determines “no train” in response to the successful reception of the GPS radio wave 17. Corresponding relay control R is issued.

In this way, in the train detection system 30, since the departure of the train 15 (moving body) is detected at any time from the side of the track (outside the moving route), not inside the track (on the moving route), it is possible to monitor traveling at a remote place. It can be useful for warnings to the site of track construction and railways.
The train detection system 30 can be detected from the side of the track by adding a set of radio wave reflector 31 and radio wave shield 32 to the train detection system 10 of the first embodiment and combining it with the GPS antenna 11. However, for the train detection system 20 of the second embodiment, another set of radio wave reflectors 31 and radio wave shields 32 are also added and combined with the GPS antenna 21 of the train detection system 20 so that the track Detection from the side can be made possible.

[Others]
In the above-described embodiment, the GPS antenna, the GPS receiver, and the determination device are separated from each other and connected by wire. However, these may be integrated as appropriate when mounting, or may be wirelessly connected. For example, a mobile phone with a GPS function is adopted as a GPS antenna and a GPS receiver, a mobile phone is placed at a position where a metal object is desired to be detected, and the detection result is notified to a remote determination device by the mobile phone communication function You may make it do.
Further, the size of the detection target object can be changed by changing the effective area of the GPS antenna installed on the ground side, or by changing the separation distance between the GPS antenna and the closest surface of the metal object to be detected. .

  Since the GPS radio wave blocking object detection system of the present invention can detect a GPS radio wave blocking object such as a metal object from the outside, the track on which the railway vehicle travels as in the train detection system described in the above embodiment, Although it is suitable for detecting the entry and advancing of railway vehicles from the side of the track, other applications are possible. For example, detecting the parking departure of a vehicle from the parking lot side where the vehicle is parked, detecting the entry / exit of a vehicle at the entrance / exit of the rental parking lot, or whether a metal object placed at a predetermined position is continuously installed or taken away It can also be applied to detecting whether or not.

1 shows the structure of a GPS radio wave blocking object detection system according to a first embodiment of the present invention, where (a) is a perspective view of the detection system, (b) is a functional block diagram of a determination device, and (c) is a flowchart of determination processing. . It is a perspective view which shows the use condition of a GPS electromagnetic wave interruption | blocking object detection system. Example 2 of the present invention shows the structure and usage of a GPS radio wave blocking object detection system, (a) is a perspective view of the detection system, (b) is a flowchart of determination processing, and (c) is a plan view of an installation location. It is. Example 3 of the present invention shows the structure and usage of a GPS radio wave blocking object detection system, (a) is a perspective view of the detection system, (b) is a plan view of the installation location, and (c) is the front of the installation location. FIG.

Explanation of symbols

10 ... Train detection system (GPS radio wave blocking object detection system),
11 ... GPS antenna (GPS ground device),
12 ... GPS receiver (GPS ground device),
13 ... Determination device, 13a ... Output relay, 13b ... Determination processing unit,
14 ... rail (track, moving route), 15 ... train (detection target),
16 ... GPS satellites, 17 ... GPS radio waves,
20 ... Train detection system (GPS radio wave blocking object detection system),
21 ... GPS antenna, 22 ... GPS receiver, 23 ... determination device,
30 ... Train detection system (GPS radio wave blocking object detection system),
31 ... Radio wave reflector, 32 ... Radio wave shield

Claims (3)

A GPS antenna for receiving GPS radio waves, a GPS receiver that processes GPS signals obtained via this antenna and outputs positioning results, and whether radio wave reception is successful or not is determined based on the output of this receiver. And a GPS radio wave blocking object detection system comprising a determination device that determines that a GPS radio wave blocking object does not exist when radio wave reception is successful and determines that a GPS radio wave blocking object exists when radio wave reception fails,
The determination device is a fail-safe device, and the GPS ground device from the GPS antenna through the GPS receiver to the determination device and the soundness of its transmission system are determined based on the output of the GPS receiver. Monitoring makes the entire system fail-safe ,
The determination device stores the installation position of the GPS antenna in advance, compares the storage position with the positioning result of the GPS receiver in light of the positioning accuracy, and when the two positions match, the GPS ground While determining that the device and its transmission system are healthy and maintaining the determination result based on the success or failure of radio reception of the GPS receiver, when the two positions do not match, the GPS ground device and its transmission system are unhealthy Regardless of the determination result based on the success or failure of radio reception of the GPS receiver by judging that there is a safety side determination that there is a GPS radio wave blocking object ,
The GPS receiver processes a GPS signal obtained via the antenna and outputs time information, and the determination device monitors the time included in the output of the GPS receiver. When the time is correctly updated, the GPS ground device and its transmission system are determined to be healthy, and the determination result based on the comparison between the two positions is maintained. The GPS ground device and its transmission system are judged to be unhealthy, and a safety-side judgment is made that a GPS radio wave blocking object exists regardless of the judgment result based on the comparison of the two positions. GPS radio wave blocking object detection system. A GPS antenna for receiving GPS radio waves, a GPS receiver that processes GPS signals obtained via this antenna and outputs positioning results, and whether radio wave reception is successful or not is determined based on the output of this receiver. And a GPS radio wave blocking object detection system comprising a determination device that determines that a GPS radio wave blocking object does not exist when radio wave reception is successful and determines that a GPS radio wave blocking object exists when radio wave reception fails,
The determination device is a fail-safe device, and the GPS ground device from the GPS antenna through the GPS receiver to the determination device and the soundness of its transmission system are determined based on the output of the GPS receiver. Monitoring makes the entire system fail-safe ,
Two sets of the GPS antenna and the GPS receiver are provided, both of the antennas are arranged away from each other in the moving direction of the GPS radio wave blocking object and facing the moving path, and the determination device includes the GPS When determining the success or failure of radio wave reception based on the output of the receiver, it is determined that there is no GPS radio wave blocking object when both radio waves are successfully received, and there is a GPS radio wave blocking object when either radio wave reception fails. It is adapted to transition the determination result based on the success or failure of the radio wave reception of the GPS receiver on the safe side by determining that,
The determination device compares the positioning results of the two sets of GPS receivers in light of the positioning accuracy and the separation distance between the two antennas. When the two positions match, the GPS ground device and its transmission system are healthy. While maintaining the determination result based on the success or failure of radio reception of the GPS receiver, the GPS ground device and its transmission system are determined to be unhealthy when the two positions do not match. Regardless of the determination result based on the success or failure of the radio wave reception of the machine, a safety side determination is made that a GPS radio wave blocking object exists ,
The GPS receiver processes both GPS signals obtained via the antenna and outputs time information, and the determination device is included in the output of the two sets of GPS receivers. Compared with the measurement accuracy in light of the measurement accuracy, when the two times coincide with each other, it is determined that the GPS ground device and its transmission system are healthy and the determination result based on the comparison between the two positions is maintained. When the two times do not coincide with each other, it is determined that the GPS ground device and its transmission system are unhealthy, and a safety-side determination that a GPS radio wave blocking object exists regardless of the determination result based on the comparison of the two positions A GPS radio wave blocking object detection system characterized by that. A GPS antenna for receiving GPS radio waves, a GPS receiver that processes GPS signals obtained via this antenna and outputs positioning results, and whether radio wave reception is successful or not is determined based on the output of this receiver. And a GPS radio wave blocking object detection system comprising a determination device that determines that a GPS radio wave blocking object does not exist when radio wave reception is successful and determines that a GPS radio wave blocking object exists when radio wave reception fails,
The determination device is a fail-safe device, and the GPS ground device from the GPS antenna through the GPS receiver to the determination device and the soundness of its transmission system are determined based on the output of the GPS receiver. Monitoring makes the entire system fail-safe ,
Two sets of the GPS antenna and the GPS receiver are provided, both of the antennas are arranged away from each other in the moving direction of the GPS radio wave blocking object and facing the moving path, and the determination device includes the GPS When determining the success or failure of radio wave reception based on the output of the receiver, it is determined that there is no GPS radio wave blocking object when both radio waves are successfully received, and there is a GPS radio wave blocking object when either radio wave reception fails. It is adapted to transition the determination result based on the success or failure of the radio wave reception of the GPS receiver on the safe side by determining that,
Corresponding to the fact that the GPS radio wave blocking object to be detected is a train and the moving route is a track for running a train, the distance between the two antennas is shorter than the minimum length of each vehicle on the train running on the track. A GPS radio wave blocking object detection system, wherein a separation distance between the two antennas is longer than a maximum length of a vehicle connecting portion of a train traveling on the track.

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