JPH0493607A - Track inspection device - Google Patents

Abstract

PURPOSE:To enable the image of an inspection of a track structure be accurately picked up, independent of the speed of a vehicle carrying an inspection device, by processing the measurement signal of a track structure according to the vehicle speed, and detecting a specific structure necessary for picking up the image of the inspection object on the basis of the aforesaid signal processing. CONSTITUTION:A track structure-related signal outputted from a track structure measurement means 1 is shaped with a measurement signal processing means 2, and the signal so shaped is made to pass through a track structure detection means 5, thereby detecting the specific structure of a track. Also, the image of an inspection object on the track is picked up with an image pickup means 6 on the basis of the aforesaid detected signal. In this case, signal wave shaping with the means 2 needs to be performed, depending upon the travel speed of a vehicle. The travel speed, therefore, is measured with a vehicle speed measurement means 3 and a signal processing control means 4 is made to function on the basis of the measured vehicle speed. The image of all inspection objects, then, can be properly picked up, even if many objects are existing on the track at random and a vehicle carrying a track inspection device is travelling at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to a track inspection device for inspecting tracks laid on the ground from a running track vehicle, and more specifically, for inspecting structures on tracks. The present invention relates to a trajectory inspection device that captures an image of an object to be inspected based on a detection result of its presence.

[Prior Art] Railway tracks are generally used under harsh conditions, so track management is essential to maintain safe running of vehicles, and it is necessary to monitor all structures on the track. Conventional track inspections involve humans actually walking on the tracks visually or using measuring instruments, with the exception of some examples such as track deviation inspections such as rail gauge, level, height, flatness, etc. It was carried out by

[Problems to be Solved by the Invention] However, the conventional measuring method as described above has a problem in that it requires a great deal of effort and time for humans to walk on the track. The purpose of this invention is to provide a track inspection device that can reliably photograph only the necessary inspection objects from a moving vehicle and inspect the tracks based on the photographed images. It is something to do.

[Means for solving the problem 1 In order to achieve the above object, the track inspection device of the present invention is mounted on a running vehicle,
As shown in the figure, fa) track structure measuring means 1 that measures the structure of the track and outputs a signal corresponding to the structure; (b) measurement signal processing means 2 that processes the signal obtained by the track structure measuring means; , (c) vehicle speed measuring means 3 for measuring the speed of a vehicle on which the entire device is mounted; fd+ signal processing control means 4 for controlling the measurement signal processing means according to the temperature measurement speed obtained by the vehicle speed measuring means; fe) track structure detection means 5 for detecting a specific structure on the track based on the output signal of the measurement signal processing means; ff) capturing an image on the track based on the signal output from the track file structure contact detection means; and an imaging means 6.

When the speed information from the vehicle speed measuring means is given digitally, the vehicle speed measuring means consists of a vehicle speed measuring section that directly outputs the speed signal as a digital signal, or when the speed information is an analog signal, converts the signal into a digital signal. It further includes an A/D conversion section that performs conversion and outputs. The signal processing control means is comprised of a microcomputer that inputs a digital speed signal and outputs a cutoff frequency determining clock having a frequency dependent on the vehicle speed. The position where the imaging means is attached to the traveling vehicle is on the rear side of the ultrasonic transmitter with respect to the direction in which the vehicle is traveling, and the amount thereof is determined by the amount of timing adjustment for emitting the imaging trigger signal.

Further, when the speed information from the vehicle speed measuring means is given in analog form, the signal processing control means converts the analog speed information into a clock having a frequency corresponding to the vehicle speed.
/F-hen 112! Consists of Department. The track structure detection means inputs the analog speed information from the two vehicle speed measurement units and the track t* structure detection signal from the error correction unit, and has a phase compensation unit that compensates for the phase delay in the signal smoothing unit. There is.

[Operation 1] In the track inspection device according to the present invention, a signal related to the track structure outputted by the track structure measuring means 1 is shaped by the measurement signal processing means 2, and this signal is passed through the track structure detecting means 5. , to detect specific structures in the trajectory. Then, based on this detection signal, the image capturing means 6 captures an image of the object to be inspected on the orbit.

Here, since the signal related to the track structure output by the track structure measuring means 1 is deformed depending on the running speed of the vehicle on which the device is mounted, the shaping by the measurement signal processing means 2 is It is necessary to carry out processing. For this purpose, the speed of the vehicle is measured by the vehicle speed measuring means 3, and the signal processing control means 4 controls the measured signal processing means 2 based on this measured value, thereby shaping the signal so that it is not affected by the traveling speed of the vehicle. I do.

It is necessary that the positional relationship between the structure on the track detected by the track structure detection means 5 and the inspection target whose image is taken is substantially constant, and they may be the same.

In this way, even if there are a large number of randomly inspected objects on the track and the vehicle equipped with the track inspection device is traveling at high speed, it is possible to reliably capture images of all the inspected objects. .

The quality of the inspected object can be automatically determined by passing the captured image through an image processing device on the spot or after taking it home, and humans can also determine the quality of the object by directly looking at the image. Good too.

[Example 1 The present invention will be explained below based on the illustrated embodiments.

This embodiment relates to an inspection of a rail fastening device (for example, testing for loosening of a rail fastening bolt), and shows a device that automatically takes an image of a fastening device from a running vehicle.

FIGS. 2 and 3 show a side view and a plan view of the configuration of this embodiment, respectively.

In FIG. 2, the entire device is mounted on a moving vehicle 2D. The inclination of the structure on the orbit is measured by the ultrasonic sensor transmitter lO1 and the receiver 10' corresponding to the orbit structure measuring means 1 shown in FIG. By inputting this measurement signal to the sleeper detection unit 12 after passing through the filter part 1.1, the sleeper 2 which is a specific structure on the orbit is detected.
6 is detected. Next, the sleeper detection signal obtained by the sleeper detection unit 12 is input to the TV left camera 5 and strobe 16 corresponding to the imaging means 6 in FIG. Capture images automatically. (Actually, signals are input to the TV camera controller 15' and strobe controller 16',
Images are captured using the TV left camera 5 and strobe 16. ) The photographed images are stored in the image memory 17. Here, the speed sensor 13 measures the traveling speed of the vehicle equipped with the device, and the measured value is input to the filter selection section 14 to select the filter of the filter part 11 according to the traveling speed.

Filter part 11. Sleeper detection part I2, speed sensor 1
3. The filter selection section 14 corresponds to the measurement signal processing means 2, track structure detection means 5, vehicle speed measurement means 3, and signal processing control means 4 shown in FIG. 1, respectively.

In this embodiment, the sleeper 26, which is not the object to be inspected, is detected when the image of the rail fastening device 27, which is the object to be inspected, is detected for the following reason. When the vehicle 20 passes through a curve, the payload installed on the vehicle (sensor for measuring the track structure) is placed on the axle (in reality, the sensor is not placed in this position). difficult, ), displaced perpendicular to the longitudinal direction of the rail. Therefore, the sensor is connected to the rail fastening device 2 at the straight part of the rail.
Even if it is possible to detect the rail fastening device 27 by placing it directly above the rail fastening device 27, when the vehicle passes through a curve, the sensor does not necessarily pass over the rail fastening device 27, and this detection may not be possible. .

On the other hand, the sleeper 26 corresponds to the rail fastening device 27 one to one, and also has sufficient length in the vertical direction of the rail length, so there is no problem even if the sensor is displaced in this direction.

FIG. 3 is a top view of FIG. The ultrasonic sensor 1O110' is arranged facing downward in the center of the vehicle to detect the sleeper 26 and detect the TV which is an imaging means.
The left camera 5 and strobe 16 are arranged so as to be located substantially on a rail 25 with a rail fastening device 27 (not shown). (The angle of view of the TV camera is large enough that even if the camera is displaced in the longitudinal direction of the rail, the rail fastening device 2
7 can take enough pictures. ) Here, considering that the rail fastening devices are located on both sides of the rail, the strobe 16 has an annular shape, and the TV left camera 5 is arranged so as to be inserted into the central opening of the strobe. (Figure 3).The reason for using an annular strobe in this way is that the shooting area on the orbit is illuminated almost uniformly, and the shooting area that is running at high speed can be momentarily fixed and photographed from directly above. , and the imaging system can be constructed in a very compact form.

Next, sleeper detection by the ultrasonic sensor transmitter IO1 receiver 10' filter part 11, sleeper detector 12, speed sensor 13, and filter selector 14 will be described. Ultrasonic sensors typically measure the distance between the sensor and an object to be inspected by measuring the time it takes for an ultrasonic pulse emitted from the sensor to be reflected from the surface of the object to be inspected and return to the sensor. However, on a general track consisting of sleepers and trackbed ballast (gravel, crushed stone), which is the subject of this example, since the sleepers and trackbed ballast are at almost the same height when viewed from the lateral position (Fig. 4), time measurement is difficult. Detection of sleepers using distance measurements is difficult.

On the other hand, even if the reflecting surface is rough, ultrasonic waves have the property of being reflected in the direction of specular reflection where the angle of incidence and the angle of reflection are equal to the reflecting surface. By utilizing this property, sleepers 26 facing directly above can be distinguished from bed ballasts 28 facing in any direction. That is, the fourth
As shown in the figure, when the ultrasonic waves emitted from the ultrasonic sensor transmitter lO are incident on the sleeper facing directly above, it is specularly reflected, and the ultrasonic sensor receiver located in this direction receives the ultrasonic waves. The ultrasonic waves are received by the IO', but if they are incident on the trackbed ballast that is not necessarily facing directly above, they are reflected in a different direction and are not received by the ultrasonic sensor receiver 10'. By measuring the strength of the received signal from the sensor receiving section 10', sleepers and trackbed ballast can be distinguished. FIG. 5 shows the amplitude change of the received signal of the ultrasonic sensor receiving section 10' after full-wave rectification. The mountain part in the diagram corresponds to the sleepers, and the other parts correspond to the trackbed ballast. Continuous waves and pulsed waves can be considered as types of ultrasound, but
In this embodiment, a continuous wave is preferable, and if distance information is used to detect track structures, a pulse wave is preferable. It is also desirable to increase the directivity of the ultrasonic sensor transmitter 10 by attaching a horn of an appropriate shape to increase the difference in received signal strength between the sleepers and the trackbed ballast, thereby increasing sleeper detection accuracy.

The trackbed ballast 28 faces in the direction of Ren and Toru, but some of them face directly above like the sleepers 26, or the trackbed ballast is placed on the top surface of the sleepers 26. In such a case, as shown in Section 5, the received signal strength may increase in areas other than the sleepers, or the received signal strength may temporarily decrease in the sleepers, which may cause errors in sleeper detection. Become.

For this reason, by utilizing the fact that the width of the sleepers is approximately constant, it is possible to perform appropriate signal processing on the received ultrasonic signals to prevent false detection. Specifically, a low-pass filter (corresponding to the filter part 11 in FIG. 2) having characteristics that matches the received signal in FIG. 5 to the sleeper passing frequency of the vehicle is used.
As shown in Figure 6, the pass frequency of the sleepers is smoothed as shown in Figure 6, and the contribution from narrow objects (roadbed ballast) that are sufficiently narrow compared to the sleepers is removed. (The frequency increases as the traveling speed increases.) 1. A filter having only one characteristic does not improve the pressure detection rate sufficiently. Therefore, it is necessary to make the characteristics of the low-pass filter variable or switchable depending on the running speed of the vehicle so that the same smoothing can be achieved even if the pass frequency of the sleepers changes. For this purpose, in this embodiment, the traveling speed of the vehicle is measured by a speed sensor 13.

Based on this value, the filter selection unit 14 selects the characteristics of the filter part 11.

FIGS. 7 to 9 show block diagrams of the signal processing system of this embodiment.

FIG. 7 shows an example in which the speed information from the vehicle speed measuring means is provided digitally, and FIGS. 8 and 9 show examples in which this information is provided in analog form.

In FIG. 7, ultrasonic waves emitted from an ultrasonic transmitter 30 driven by an ultrasonic driver 30' are received by an ultrasonic receiver 31 after being reflected on a track 24. The received ultrasonic signal is amplified by a received signal amplification section 31', and then its envelope is detected by a received signal envelope detection section 32. Here, the envelope is detected by full-wave rectifying an ultrasonic signal with a frequency of several tens of kHz and passing it through a low-pass filter with a cutoff frequency of several hundred Hz higher than the pass frequency of the sleepers. Since the pass frequency of this sleeper depends on the vehicle speed, the signal smoothing section 33, which can switch the filter characteristics according to the vehicle speed as described above, smooths the ultrasonic envelope signal in a manner that is not affected by the vehicle speed. to make
The signal smoothing section 33 uses a programmable filter, especially a switched capacitor filter whose cutoff frequency can be changed depending on the frequency of the input clock. By making the frequency of the clock input to the switched capacitor filter dependent on the speed, it is possible to perform smoothing that is independent of the vehicle speed. Next, the clock input to this filter will be explained. The vehicle speed measuring section 34 measures the vehicle speed using a speed generator or the like attached to the wheels of the vehicle, and outputs the speed information as a digital signal. This digital speed signal is sent to the microcontroller 35.
from which a cutoff frequency determination clock with a frequency dependent on vehicle speed is output. Then, this cutoff frequency determination clock is input to the signal smoothing unit 33, and the ultrasonic envelope signal is smoothed in a manner that is not affected by the vehicle speed.The ultrasonic smoothed signal obtained in this way is section 36 to detect a specific track structure (sleeper). In the comparator section 36, a certain voltage threshold is set for the ultrasonic smoothed signal as shown in FIG. 6, and when the signal exceeds this threshold, it is determined that it is a sleeper. outputs a digital track structure detection signal. If this track structure detection signal is input as an imaging trigger signal to the imaging unit 38, an image of the target rail fastening device can be captured, but the following processing is further performed here. Mistake correction department 37
This method further reduces false detection of specific track structures that could not be removed even with the above processing, and the specific details will be explained later. The track structure detection signal passed through the error correction unit 37 has a one-to-one correspondence with the sleepers, but the time from when the ultrasonic sensor passes the sleepers until the track structure detection signal is output is It is not necessarily constant. The reason for this is that the signal smoothing unit 33 performs filtering processing using a low-pass filter with a variable cutoff frequency, resulting in a signal phase delay (M-interval delay) that depends on the cutoff frequency. It is. If this track structure detection signal with inconsistent timing is used as an imaging trigger signal, the position of the rail fastening device will not be constant depending on the captured image, and when inspecting the rail fastening device by image processing, the image processing time will increase. There is a possibility that errors may occur. Furthermore, if the imaging range is narrowed in order to increase the resolution of the image, there is a possibility that the rail fastening device will be removed from the image. In order to prevent this, it is necessary to compensate for the phase delay in the signal smoothing unit 33, but here, the microcomputer 35 is used to calculate the time from the track structure detection signal output at various timings to the generation of the imaging trigger signal. In other words, the time from when the ultrasonic sensor passes through the sleeper until it emits an imaging trigger signal is adjusted. The amount of phase delay in the signal smoothing section 33 depends on the cutoff frequency of the low-pass filter, that is, the vehicle speed, and this is a known amount for each vehicle speed. The product of this phase delay time and the vehicle speed corresponds to the photographing position of the rail fastening device in the image, but since the vehicle speed information is input to the microcomputer 35, this and the previously stored Bakun This timing adjustment is performed according to the converted phase delay information, and the photographing position of the rail fastening device in the image is kept constant (
However, in this case, there is always a time delay between the ultrasonic sensor passing through the sleeper and the time it issues the imaging trigger signal, so the mounting position of the imaging unit 38 on the vehicle may vary. As shown in FIG. 10, it is necessary to place it behind the ultrasonic sensor with respect to the vehicle traveling direction. (In the figure, the vehicle is moving to the right.) The amount is determined by the timing adjustment amount described above1, and the relationship between these is as shown in the following equation.

La = d / V - tdm where ta is the timing adjustment time for issuing the imaging trigger signal by the microcomputer or the phase compensation unit described below, d is the distance between the ultrasonic sensor measurement area on the orbit and the camera image loss area, ■ Vehicle Speed td fV) Phase delay time in the signal smoothing section.

Furthermore, although the embodiment shown in Fig. 1O cannot handle cases where the vehicle is traveling in the opposite direction, ultrasonic sensors are attached to both sides of the bottle image portion 38, and the sensors to be used can be switched depending on the traveling direction. That's fine.

Next, the error correction section 37 will be explained. In the present invention, smoothing is performed in a manner that is not affected by the vehicle speed, so that most of the glitch detection can be eliminated. However, if there is a structure on the track other than the sleepers that has a vertical surface that is so wide that it cannot be ignored by the sleepers (for example, a cover for a communication line),
Also, if there is a structure on the sleepers that has a surface that faces in a direction other than vertical and has a width that cannot be ignored relative to the sleepers (for example, if the bed ballast is placed on a wide area almost in the center of the sleepers) ), there is a possibility that false positives cannot be completely removed by the above-mentioned smoothing alone. The error correction unit 37 is provided to deal with such a case, and two possible methods will be described as examples of how to deal with it. The first example uses multiple ultrasonic sensors as shown in FIG. 11 (the figure shows a case where three ultrasonic sensors are used), and one or more of these Even if there is a false detection due to the above-mentioned causes in (not all) cases, this can be removed by taking an appropriate combination of logical sums and products of the track structure detection signals of the comparator parts of these sensors, for example. be able to. This method can be used if the structure that is causing the false detection is concentrated in a certain area, and some of the detection areas of multiple sensors are outside of this structure (for example, if a part of the sleeper Effective only when the track bed ballast is solidified). In this method, an ultrasonic transmitter 30 an ultrasonic driver 30
', Ultrasonic receiver:) 1, Received signal amplification section 31, Received signal envelope detection section 32, Signal smoothing section 33. The number of comparator sections 36 is equal to the number of ultrasonic sensors. However, if the frequencies of the plurality of ultrasonic sensors are made sufficiently different from the receiving frequency band of the ultrasonic receiver 31, the plurality of ultrasonic waves can be received without interference, and the special electric circuit can be used. No more need to be added. The second example is to determine whether the time reflected from the vertical track structure corresponds to the time required to pass through the sleepers.Since the width of the sleepers is known, it is necessary to use covers for communication lines that are narrower than this. can be identified and removed.

However, since the time required to pass the sleepers depends on the vehicle speed, the microcomputer 35 calculates this based on vehicle speed information and sends the result to the error correction section 37.

The error correction unit 37 determines whether the track structure is a sleeper based on the result, and if it is a sleeper, inputs the track structure detection signal to the microcomputer 35 as described above, and then outputs the imaging trigger signal. emits.

The embodiment shown in FIG. 8 is a case where the speed information from the vehicle speed measurement section 34 is given in analog form. Here, the analog speed information is converted into digital by the D/D conversion section 39, and this is input to the microcomputer 35. . Other than this, it is the same as the embodiment of the 7th ward.

The embodiment shown in FIG. 9 is a case where the microphone is not used, and the analog speed information given from the vehicle speed measuring section 34 is
The F converter 40 converts the clock into a clock having a frequency corresponding to the vehicle speed, and uses this as the cutoff frequency determining clock for the switched capacitor filter of the signal smoother 33, similar to the embodiment shown in FIG. Furthermore, in the embodiment shown in FIG. 7, the phase delay in the signal smoothing section 33 is compensated by a microcomputer, but here this is done by an electric circuit by inputting analog speed information to the phase compensation section 41. There is. Other aspects are the same as the embodiment shown in FIG.

It goes without saying that the embodiments shown in FIGS. 7 to 9 described above are not necessarily limited to these, and may include those in which some of them are omitted and those in which they are combined.

Ultrasonic transmitter 30 in FIG. The ultrasonic driving section 30, the ultrasonic receiver 31, the received signal amplifying section 31', and the received signal envelope detecting section 32 serve as the track structure measuring means 1 shown in FIG. Measuring section 34
corresponds to the vehicle speed measuring means 3, the microcomputer 35 to the signal processing control means 4, the comparator section 36 and the error correction section 37 to the track structure detection means 5, and the imaging section 38 to the pseudo-imaging means 6.

Further, in FIG. 8, the vehicle speed measuring section 34 and the A/D converting section 3
9 is the vehicle speed measuring section 34 in FIG. 1, and in FIG.
The F conversion section 40 corresponds to the signal processing control means 4, and the comparator section 36, error correction section 37, and phase compensation section 41 correspond to the track structure detection means 5, respectively.

The imaging trigger signal obtained in this way is sent to the imaging unit 38.
input to a compatible TV camera and strobe to take an image of the rail fastening device. In order to inspect the actual rail fastening device using this image, it is necessary to visualize the quality of the rail fastening device in some way. There is a method of drawing a white line in a fixed direction on the head surface and determining the loosening by the rotation angle of the white line as the bolt loosens. Is there a way to determine whether it is loose or not? Furthermore, in the case of a bunt roll rail fastening device using a wire spring, it is sufficient to determine whether or not it has come loose.

If it is possible to visualize whether the rail fastening device is good or bad in this way, it may be possible to judge by looking at the image of the rail fastening device taken home, or by using an image processing device, either on the spot or after taking it home. By image processing the image of the rail fastening device, it is possible to automatically inspect the rail fastening device on the track.

Although the rail fastening device inspection using sleepers has been described above, the present invention is not limited to this.
It can be used as many track inspection devices. For example, in the above embodiment, it was explained that sleepers and trackbed ballast can be identified using the ultrasonic signals shown in Fig. 5, but if mud plumes occur on the track, the signal changes due to the reflection of the ultrasonic waves. Since this changes, the presence of mud plume can also be detected with a configuration similar to that shown in FIGS. 7 to 9.

[Effects of the Invention] Since the present invention is configured as described above, it has the following effects.

According to the track inspection device of the present invention, a measurement signal for a track structure is processed according to its running speed, thereby detecting a specific component necessary for capturing an image of the object to be inspected. , regardless of the speed of the vehicle,
You can reliably capture the image. Therefore, by mounting such a track inspection device on a running vehicle and photographing images of the objects to be inspected, it is possible to obtain images of a large number of objects to be inspected in a short time. When combined with this, track inspection can be almost automated, making track management much more efficient than before.

[Brief explanation of drawings]

FIG. 1 is a block diagram conceptually showing the configuration of the present invention, FIG. 2 is a side view of the configuration of an embodiment of the present invention, and FIG. 3 is a plan view of the embodiment of FIG. , Fig. 4 is an explanatory diagram of sleeper discrimination, Section 5 is an explanatory diagram of the ultrasonic reception signal, Fig. 6 is an explanatory diagram of the signal in Fig. 5 after processing, and Figs. Fig. 9 is a block diagram of the signal processing system, Fig. 10 is a plan view showing the mounting position of the imaging unit, and Fig. 11 is a plan view showing the mounting position of the imaging unit. be. [Explanation of symbols of main parts] 1-----One track structure measuring means 2-11111 Measurement signal processing means 3---One vehicle speed measuring means 4---One signal Processing control means 5 --- Track structure detection means 6 --- Imaging means 10.30 --- Ultrasonic transmitter 10', 31 --- Ultrasonic receiver Vessel 30'--
---Ultrasonic drive unit 31' ---Received signal amplification section 32--Received signal envelope detection section 33--
--- Signal smoothing section 34 --- Vehicle speed measuring section 35 --- Microcomputer 3B --- Comparator section 37 --- Error correction section 38 --- ---1 Imaging section 39-----A/D conversion section 4O-------V/F conversion section 41--1 Phase compensating section Figure 1 Ballast sleeper Ballast sleeper sleeper Ballast sleeper Ballast sleepers Ballast sleepers Figure Figure Figure Figure

Claims (1)

[Scope of Claims] 1. A track inspection device that is mounted on a running vehicle and takes images of a track structure, comprising: track structure measuring means that measures the structure of the track and outputs a signal according to the structure; measurement signal processing means for processing signals obtained by the track structure measurement means; vehicle speed measurement means for measuring the speed of a vehicle on which the entire device is mounted; and measurement signal processing means for processing signals obtained by the vehicle speed measurement means. a signal processing control means for controlling the measurement signal processing means; a track structure detection means for detecting a specific structure on the track using the output signal of the measurement signal processing means; and a track structure detection means for detecting a specific structure on the track using the detection signal of the track structure detection means A track inspection device comprising: an imaging means for taking pictures. 2. The trajectory structure measuring means includes an ultrasonic drive section, an ultrasonic transmitter driven by the drive section, and an ultrasonic receiver that receives the ultrasonic waves emitted from the transmitter after being reflected on the trajectory; It consists of a received signal amplification section that amplifies the received ultrasonic signal, and a received signal envelope detection section that detects the envelope of the amplified ultrasonic signal, and the measurement signal processing means includes a received signal envelope detection section that amplifies the received ultrasonic signal. The vehicle speed measuring means consists of a signal smoothing section that smoothes the ultrasonic envelope signal of the signal into a form that is not affected by the vehicle speed, and the vehicle speed measuring means includes a vehicle speed measuring section that measures the vehicle speed and outputs the speed information directly as a digital signal. or when the speed information is an analog signal, the signal processing control means further includes an A/D conversion section that converts the signal into a digital signal and outputs it, and the signal processing control means inputs the digital signal of the speed and outputs the signal depending on the vehicle speed. The track structure detection means includes a microcomputer that outputs a cutoff frequency determining clock having a frequency determined by the signal smoothing section and inputs the clock to the signal smoothing section, and the track structure detection means detects ultrasonic waves from the signal smoothing section that are independent of vehicle speed. A specific structure on the track is detected by inputting a smoothed signal, a certain voltage threshold is set for the ultrasonic smoothed signal, and when the smoothed signal exceeds this threshold a comparator section that determines that the structure is the specific structure and outputs a digital track structure detection signal; and an error correction unit that outputs a track structure detection signal with a specific structure detection error removed or reduced, and the imaging means inputs the track structure detection signal from the error correction unit to the microcomputer and It consists of an imaging section that inputs an imaging trigger signal outputted after compensating for the phase delay in the signal smoothing section, and the mounting position of the imaging section on a running vehicle is determined by the formula ta=d/V with respect to the vehicle traveling direction. -td (V) (where, td (V) is the phase delay time in the signal smoothing section, V is the vehicle speed, d is the distance between the measuring section of the ultrasonic transmitter on orbit and the imaging section, and ta is the microcomputer 2. The trajectory inspection device according to claim 1, wherein the trajectory inspection device is positioned rearward from the ultrasonic transmitter by an amount determined by a timing adjustment time for emitting an imaging trigger signal. 3. The trajectory structure measuring means includes an ultrasonic drive section, an ultrasonic transmitter driven by the drive section, and an ultrasonic receiver that receives the ultrasonic waves emitted from the transmitter after being reflected on the trajectory; It consists of a received signal amplification section that amplifies the received ultrasonic signal, and a received signal envelope detection section that detects the envelope of the amplified ultrasonic signal, and the measurement signal processing means includes a received signal envelope detection section that amplifies the received ultrasonic signal. The vehicle speed measuring means includes a signal smoothing section that smoothes the ultrasonic envelope signal of the vehicle into a form that is not affected by the vehicle speed, and the vehicle speed measuring means includes a vehicle speed measuring section that measures the vehicle speed and outputs the speed information as an analog signal. The signal processing control means includes a V/F conversion section that converts the analog speed information into a clock having a frequency corresponding to the vehicle speed, and the track structure detection means includes a V/F conversion section that converts the analog speed information into a clock having a frequency corresponding to the vehicle speed. A specific structure on the track is detected by inputting an ultrasonic smoothed signal, and a certain voltage threshold is set for the ultrasonic smoothed signal. a comparator unit that determines that the specific structure is the specific structure and outputs a digital track structure detection signal when the track structure detection signal is exceeded; an error correction unit that outputs a track structure detection signal with a specific structure detection error removed or reduced when there is an error in detecting a specific structure; and analog speed information from the vehicle speed measurement unit and track structure information from the error correction unit. a phase compensation section that receives a detection signal as an input and compensates for a phase delay in the signal smoothing section; the imaging means includes an imaging section that receives an imaging trigger signal output from the phase compensation section; The mounting position on a running vehicle is determined by the formula ta=d/V-td(V) in the direction of vehicle travel (where td(V) is the phase delay time in the signal smoothing section, V is the vehicle speed, and d is the distance between the measurement part of the ultrasonic transmitter on orbit and the imaging unit, and ta is the timing adjustment time for emitting the imaging trigger signal by the phase compensation unit. The track inspection device according to item 1.