JP6145417B2 - Train position detection apparatus and train position detection method - Google Patents

Description

  The present invention relates to a train position detection device and a train position detection method, and more particularly to a train position detection device and a train position detection method using a train speed measurement method that detects a train speed using a Doppler radar type sensor.

  A known method for detecting the speed of a train is to detect and calculate the rotation of a wheel. In the conventional method, the train travel distance is obtained from the speed and elapsed time, and the train position is determined by further integrating. However, an error occurs in the measurement speed due to idling and sliding of the wheels. In addition, since the wheel diameter changes due to wear of the wheels due to running of the train, an error occurs in the measurement speed. 2. Description of the Related Art In recent years, a technique has been demanded in which an onboard device mounted on a train recognizes the position of the own train and compares it with a given train control signal to determine the stop target position of the own train. In this case, it is very important to accurately recognize the position of the own train with the on-board device. Therefore, a new train position detection device mounted on the train has been demanded.

  As such a technique, for example, a train speed detection device that detects the speed of a train using a Doppler radar type sensor has been proposed (for example, see Non-Patent Document 1). Specifically, in a state where a device including a millimeter wave transmission / reception antenna is installed under the floor of a vehicle, the reflected wave is obtained by irradiating the millimeter wave toward the track. The vehicle speed is calculated using the Doppler effect. The own train position is obtained based on this train speed detection device.

Takayuki Kasai et al., "Development of non-contact speedometer using millimeter wave", Railroad Saipan Symposium Proceedings No. 49, November 2012

  By the way, in the method of correcting the velocity component in the oblique direction obtained from the sensor by using the inclination angle of the sensor with respect to the roadbed, when the sensor is displaced and the inclination angle becomes unstable, or the detection area of the sensor is widened. In this case, for example, when the beam is not a laser, there is a problem that the speed estimation error becomes large.

  FIG. 1 shows the spread state of radar waves when a speed component is estimated using a sensor whose detection area is not a line (for example, a Doppler radar sensor). As shown in the figure, the estimated speed component has a spread error. An arrow indicated by a solid line indicates the center of the radar sensor, and an arrow indicated by a broken line around the center indicates the spread. If it is as it is, it is unclear at which position in the range the reflected wave is detected, and an error may have occurred.

  Especially for train position detection, train speed information is very important, and if error in speed information accumulates, it may interfere with smooth train operation, and countermeasure technology is required. It had been. In particular, when the train operation interval is short, very accurate speed detection is necessary from the viewpoint of safety, and the train position using the train speed detection device that detects the train speed using a Doppler radar type sensor The introduction of the detection device has been a very big problem.

  In the technique disclosed in Non-Patent Document 1, sufficient consideration is not given to the deviation of the tilt angle similar to the above, and another technique is required.

  This invention is made | formed in view of the above situations, Comprising: It is providing the technique which solves the said subject.

The train position detection device of the present invention includes a Doppler radar type sensor installed at the bottom of a train with a predetermined inclination angle with respect to the road bed as an outgoing wave irradiation direction, and a distance to a reflection position calculated by the sensor. The actual inclination angle calculation unit for calculating the actual angle of the direction of the reflection position of the transmitted wave from the altitude at which the sensor is installed, the angle calculated by the actual inclination angle calculation unit, and the sensor From the detected speed information, it is assumed that the train speed calculation unit that calculates the speed of the train, the feature point extraction unit that specifies the feature point of the speed calculated by the train speed calculation unit, and the feature point are expressed. A position information recording unit that preliminarily holds the position of the train, and a position estimation unit that estimates the position of the train from the feature point and the position of the position information recording unit.
The position estimation unit may detect the state of the roadbed reflected by the transmitted wave based on the feature points.
The train position detection method of the present invention includes a distance to a reflection position calculated by a Doppler radar type sensor installed at the bottom of a train with a predetermined inclination angle with respect to the road bed as an irradiation direction of a transmitted wave, and the sensor The actual inclination angle calculation step of calculating the actual angle of the direction of the reflection position of the transmitted wave from the installed altitude, the angle calculated by the actual inclination angle calculation step, and the speed detected by the sensor From the information, a train speed calculation step for calculating the speed of the train, a feature point extraction step for specifying a feature point of the speed calculated by the train speed calculation step,
A position estimation step of estimating the position of the train by collating the feature points with data in which the positions at which the feature points are expected to be recorded are recorded.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which improves the speed | rate detection of the train using a Doppler radar type sensor and the specific precision of the position of a train can be provided.

It is a figure which shows typically the spread condition of a radar wave in the case of estimating a speed component using the sensor which the detection area which concerns on background art is not a line. It is a functional block diagram which shows the structure of the train 1 based on this embodiment. It is a figure explaining the principle which installs a Doppler radar type sensor in the bottom of a train and makes an angle of inclination with respect to the roadbed, and measures a train speed (this presumed speed) concerning this embodiment. It is a figure explaining the principle which installs a Doppler radar type sensor in the bottom of a train and makes an angle of inclination with respect to the roadbed, and measures train speed (comparative estimated speed) concerning this embodiment. It is a graph which shows the field verification experiment result of this estimation speed, comparison estimation speed, and GPS speed concerning this embodiment.

  Next, modes for carrying out the present invention (hereinafter, simply referred to as “embodiments”) will be specifically described with reference to the drawings.

  FIG. 2 is a functional block diagram showing the configuration of the train 1 according to the present embodiment, and here, focusing attention on the speed calculation function.

  The train 1 includes a Doppler radar type sensor 20 on the bottom surface 2. The Doppler radar type sensor 20 is installed with a predetermined inclination angle θ with respect to the roadbed 90. Therefore, the Doppler radar type sensor 20 detects a velocity component in an oblique direction. That is, the transmission direction of the transmission wave is set to the direction of the predetermined inclination angle θ.

  Further, the train 1 is based on the speed calculation unit 10 that estimates the horizontal speed of the train 1 based on the speed component detected by the Doppler radar type sensor 20, that is, the traveling speed, and the speed estimated by the speed calculation unit 10. Is provided with a position information unit 15 for specifying the position of the train 1. Conventionally, the speed is calculated based on the rotational speed and wheel diameter of the wheel rolling on the track 91.

The speed calculation unit 10 calculates the distance information RH _Pk and the speed information V _Pk based on the reflected wave with respect to the transmitted wave irradiated in the oblique forward irradiation direction by a calculation method described later, and the Doppler radar type sensor 20 is installed. The train speed RV1 (main estimated speed) is estimated from the installed installation height information h. That is, the Doppler radar type sensor 20 and the speed calculation unit 10 realize the same function as a conventional speedometer.

Specifically, the speed calculation unit 10 includes an actual inclination angle calculation unit 11 and a train speed calculation unit 12. The actual inclination angle calculation unit 11 calculates the actual transmitted wave and reflected wave with respect to the road bed 90 from the distance information _RHPk obtained by the Doppler radar type sensor 20 and the height (installation height h) of the Doppler radar type sensor 20 at the time of installation. The tilt angle (tilt angle θ _Pk ) is calculated.

The train speed calculation unit 12 estimates the horizontal component VH _Pk of each speed information from the tilt angle θ _Pk calculated by the actual tilt angle calculation unit 11 and the radar speed information V _Pk , and further calculates the arithmetic average of them. Estimated as speed RV1. The estimated train speed RV1 is displayed on, for example, a speedometer.

  The position information unit 15 specifies the position of the train 1, that is, the current location, based on the train speed RV1 estimated by the speed calculation unit 10. Therefore, the position information unit 15 includes a position estimation unit 16, a position information recording unit 17, and a feature point extraction unit 18.

As described above, the speed calculation unit 10 reflects the actual tilt angle (tilt angle θ _Pk ) based on the height (installation height h) of the Doppler radar type sensor 20 and the speed information V _Pk. Detected. As a result, if there is a change in the state of the roadbed 90 that is a reflection surface, that is, the roadbed 90 has a height different from the installation height h, a characteristic tendency (hereinafter referred to as “feature”) of the estimated train speed RV1 Point ”).

  For example, at a railroad crossing, the trajectory and the road are at the same height for cars and people who cross, and therefore the reflecting surface (the roadbed 90) substantially matches the height of the trajectory 91. A unique value appears in the detected speed. In addition, in a bridge without a roadbed such as an iron bridge, the reflection surface becomes lower than a normal roadbed or a riverbed under the iron bridge, and the reflection surface (the roadbed 90) becomes lower. A unique value appears in. The feature point extraction unit 18 extracts a unique value as a feature point. Specific examples of the feature points are shown in the verification experiment results of FIG. 5 described later. On the other hand, the positions and lengths of railroad crossings and railway bridges are known accurately in advance. Therefore, the position information recording unit 17 records the position and length of the railroad crossing and the iron bridge. The position estimation unit 16 accurately identifies the position of the train 1 by comparing the point where the feature point extracted by the feature point extraction unit 18 is generated with the position information recording unit 17.

With reference to FIG. 3, the basic speed detection method (this estimated speed) in the present embodiment will be specifically described. Here, it is assumed that a transmission wave is irradiated at a predetermined tilt angle θ _Pk from the antenna center C of the Doppler radar type sensor 20 to the road bed 90 which is a reflection surface, and returns to the Doppler radar type sensor 20 as a reflected wave.

As shown in the equation (1), each tilt angle θ _Pk is estimated using the distance information RH _{Pk of} each detected sampling. However, the subscript Pk is used as the sample number. The installation height information h is the height from the road bed 90 to the antenna center C of the Doppler radar type sensor 20.

式（３）に示すように、式（２）で求めた水平成分ＶＨ_Ｐｋの所定期間の相加平均を取り、その相加平均を列車速度ＲＶ１とする。

Next, as shown in equation (2), from the speed information _{V Pk} tilt angle theta _Pk and Doppler radar sensors 20 obtained by the formula (1), estimates a horizontal component _{VH Pk} of the respective speed information _{V Pk} .

As shown in Expression (3), the arithmetic average of the horizontal component _VHPk obtained in Expression (2) over a predetermined period is taken, and the arithmetic average is taken as the train speed RV1.

  Next, with reference to FIG. 4, a method for estimating the comparative estimation speed by the calculation method used in the background art shown in FIG. 1 will be described.

Here, the velocity information _VPk estimated by the Doppler radar type sensor 20 and the tilt angle information θ (fixed value; for example, 45 °) which is the outgoing direction of the outgoing wave set when the Doppler radar type sensor 20 is installed on the bottom surface 2. ) To estimate the train speed RV2.

As shown in Expression (4), the horizontal component VH _Pk of the speed information V _Pk of each detected sampling is estimated from the speed information V _Pk and the tilt angle information θ. However, the subscript Pk is used as the sample number. The difference from the above equation (2) is that cos θ is a fixed value.

Next, as shown in Expression (5), an arithmetic average of the horizontal component _VHPk obtained in Expression (4) over a predetermined period is taken, and the arithmetic average is set as a train speed RV2.

  FIG. 5 demonstrates the train speed estimated using the correction method proposed in the present embodiment (main estimated speed), the comparative estimated speed calculated by the conventional method, and the speed calculated using GPS (GPS speed). The experimental comparison results are shown. FIG. 5A shows a measurement result of about 360 seconds, FIG. 5B shows an enlarged area A1 of FIG. 5A, and FIG. 5C shows FIG. 5B. The area A2 of FIG. In the demonstration experiment, a microwave of 24 GHz was used as a transmission wave.

  As shown in the figure, the comparison estimated speed had an error of about 4 to 5% with respect to the GPS speed. On the other hand, the estimated speed is substantially the same as the GPS speed, and the above error is substantially eliminated. Therefore, when applying the Doppler radar type sensor 20 to a speedometer, a highly accurate speedometer can be realized.

  Further, as shown in the region B1 and the region B2, the graph of the estimated speed appears in a convex shape (mountain shape) in these sections. Railroad crossings are installed at these points, and the installation height h in Equation (1) above is a large value compared to the height up to the actual reflection point. As a result, the calculated estimated speed is also increased. Moreover, as shown to the area | region C1 and the area | region C2, the graph of this estimated speed has appeared in convex shape (valley shape) in these areas. Iron bridges are installed at these points, and the installation height h of the above-described equation (1) is a small value compared to the height to the actual reflection point. As a result, the calculated estimated speed is also reduced.

  Here, referring to the graph of the comparative estimated speed, the feature point appears in a relatively easy-to-understand state at a point where a great change occurs in the roadbed (roadbed 90) like an iron bridge. ) The feature point appears in a state where it is difficult to understand at a point where the change in () is small. Moreover, since the speed itself has an error of about 4 to 5%, it is inferior in terms of reliability. On the other hand, in the graph of the estimated speed, feature points clearly appear even at a point where the change is small, such as a level crossing. As a result, the feature points can be used effectively and the position can be specified accurately.

  When the appearance state of the feature point is different from the assumed state, the position estimation unit 16 may notify the transportation instruction department that manages the operation of the train 1 to that effect. When receiving a similar notification from a plurality of trains 1, the transportation command department can take an early countermeasure because there is a possibility that some abnormality has occurred on the route. For example, when the appearance time of a feature point is long, when a feature point appears at a place where the feature point does not appear, or when the feature point does not appear despite the place where the feature point should appear originally Can be illustrated.

The effects of the present embodiment are summarized as follows.
(1) Even when the tilt angle of the Doppler radar type sensor 20 deviates due to traveling or the like, the tilt angle in the direction of the actual transmitted wave (reflected wave) is estimated, so that the correction is appropriately made. I can do it. As a result, the accuracy of train speed measurement can be improved.
(2) Even when the detection range of the Doppler radar type sensor 20, that is, the irradiation direction is widened, the inclination angle with respect to the velocity component of the detected wave that is actually reflected and returned can be estimated. Accuracy can be improved.
(3) By comparing the method of estimating the velocity by correcting the velocity component with the inclination angle and the method of estimating the inclination angle using the distance component and correcting the velocity component using the inclination angle, the roadbed 90 When the height of the (roadbed) changes, the point (feature point) can be detected. And the position of the train 1 can be correctly grasped | ascertained by collating the position information recording part 17 which recorded the position and length of a railroad crossing and an iron bridge, and a feature point.
(4) A change in the state of the route (track) can be grasped according to the appearance state of the feature point, and the confirmation work of the safety measure can be performed at an early stage.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of these components, and such modifications are also within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Train 2 Bottom face 10 Speed calculation part 11 Actual inclination angle calculation part 12 Train speed calculation part 15 Position information part 16 Position estimation part 17 Position information recording part 18 Feature point extraction part 20 Doppler radar type sensor 90 Road bed 91 Orbit

Claims (3)

A Doppler radar type sensor installed at the bottom of the train with a predetermined inclination angle with respect to the roadbed as the direction of irradiation of the outgoing wave;
An actual inclination angle calculation unit for calculating an actual angle of the direction of the reflection position of the transmitted wave from a distance to the reflection position calculated by the sensor and an altitude at which the sensor is installed;
From the angle calculated by the actual inclination angle calculation unit and the speed information detected by the sensor, a train speed calculation unit that calculates the speed of the train;
A feature point extraction unit that identifies a feature point of the speed calculated by the train speed calculation unit;
A position information recording unit that holds in advance a position where the feature point is assumed to be expressed;
A train position detection device comprising: a position estimation unit that estimates a train position from the feature point and the position of the position information recording unit.   The train position detection device according to claim 1, wherein the position estimation unit detects a state of a roadbed reflected by the transmitted wave based on the feature points. From the distance to the reflection position calculated by a Doppler radar type sensor installed at the bottom of the train with a predetermined inclination angle with respect to the road bed as the direction of irradiation of the outgoing wave, and the altitude at which the sensor is installed, An actual inclination angle calculating step of calculating an actual angle of the direction of the reflection position of the transmitted wave;
From the angle calculated by the actual inclination angle calculating step and the speed information detected by the sensor, a train speed calculating step of calculating the speed of the train,
A feature point extraction step for identifying a feature point of the speed calculated in the train speed calculation step;
A train position detection method comprising: a position estimation step of estimating the position of a train by comparing the feature points with data in which positions where the feature points are assumed to appear are recorded.

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