Digital wheel sensor

Abstract

The utility model discloses a digital wheel sensor, which comprises a wheel sensor sensing module and a digital signal processing board, the digital signal processing board comprises an AD acquisition module, an FPGA chip and an amplification circuit, and the wheel sensor sensing module is connected with an acquisition input end of the AD acquisition module through an analog signal output circuit. The output end of the AD acquisition module is connected with the input end of the FPGA chip, the output end of the FPGA chip is connected with the input end of the amplification circuit, and the amplification circuit is connected with a railway 5T system and other systems through the digital signal output circuit. According to the digital wheel sensor, analog signals output by the magnetic steel are converted into digital signals, the digital signals can be completely received, the signals are stable, existing interference signals have no influence on the digital wheel sensor, and detection results of a railway vehicle bottom face detection system in the later period are more accurate.

Description

Technical Field

[0001] The utility model belongs to the technical field of wheel sensors, and particularly relates to a digital wheel sensor. Background Art

[0002] When a wheel sensor, i.e., a road-vehicle force sensor, detects a wheel speed signal on an automobile, the most commonly used sensor is an electromagnetic induction sensor. Generally, the sensor is installed on the non-rotating part of the wheel assembly (such as a steering knuckle or an axle head) and faces a toothed ring made of a magnetically conductive material that rotates with the wheel. When the toothed ring rotates relative to the sensor, due to the change in magnetic resistance, an alternating voltage signal is excited on the sensor. The frequency of this alternating voltage is proportional to the wheel speed. The ECU uses a dedicated signal processing circuit to convert the sensor signal into a square wave of the same frequency, and then calculates the wheel speed by measuring the frequency or period of the square wave.

[0003] The wheel sensor of a railway vehicle is a key component stuck inside the rail in trackside equipment such as the THDS infrared axle temperature detection system, TFDS dynamic image detection system for freight car operation faults, TPDS ground safety monitoring system for freight car operation status, TADS rail-side acoustic diagnosis system for early faults of freight car rolling bearings, and AEI car number identification system of railway vehicles.

[0004] The wheel sensors on the existing market all output analog signals. During the reception and transmission of signals, the analog signals will be interfered with. Even though the existing wheel sensors have made great changes in minimizing electrical interference, these interference signals still exist. If a wheel sensor has poor anti-electrical interference ability, it will cause large errors in sensor testing, thus affecting the detection results of the railway vehicle bottom detection system.

[0005] The reason is that the analog signal outputs a sine wave, and the magnitude of the sine wave is determined by the speed at which the wheel of the railway vehicle passes. The faster the wheel speed, the larger the output waveform, and the slower the speed, the smaller the output waveform. At the rear end of the wheel sensor, a device processes the analog signal. Due to the existence of interference, the final processed result may be incorrect. In addition, in analog signals, it is very likely to be affected by other interferences. Some strong interference signals will submerge or even cancel out the normal analog signals. As a result, some relatively weak analog signals will be completely lost. Especially when some interference signals are much larger than the analog signals, these analog signals cannot be recognized at the rear end at all, and these analog signals will be missed.

[0006] For current wheel sensors, the main interference signals come from the cables between the wheel sensor and the device, the lead wires of the magnet itself, and the interference induced in the coil on the magnet.

[0007] Specifically, 1. The distance between the permanent magnet and the device is usually between 10 and 100 meters, and in some cases even farther. The cable connecting the permanent magnet and the device will generate interference signals. 2. The lead wire of the permanent magnet itself will also generate interference signals. 3. Since there are coils on the permanent magnet, the more turns of the coil winding, the stronger the ability to receive interference. Therefore, the coil itself will sense some interference signals. Although some of the interference signals generated by these interference sources are very weak, they actually exist.

[0008] Also, because the analog signal generated by the wheel sensor is also a type of alternating voltage, as Figure 8 shown, this analog signal does not have a consistent magnitude and there will be fluctuations during actual use, as shown by the different-sized waveform diagrams in the figure. When the signal is weak and encounters interference signals, the interference signals generated by the above-mentioned interference signal sources are also a type of alternating voltage. The weak analog signal may become weak or even be cancelled out when encountering interference signals.

[0009] Therefore, how to modify the existing wheel sensor so that the output signal can be received as much as possible while being stable and reliable has become the direction of efforts for those skilled in the art. Utility Model Content

[0010] The purpose of the present utility model is to provide a digital wheel sensor, which converts the analog signal output by the permanent magnet into a digital signal and then outputs it. The digital signal has the characteristic of stability and is not affected by interference signals, which can completely solve the deficiencies of the above-mentioned existing technologies.

[0011] The purpose of the present utility model is achieved through the following technical solutions: A digital wheel sensor includes a wheel sensor induction module and a digital signal processing board, and is characterized in that: the digital signal processing board includes an AD acquisition module, an FPGA chip, and an amplification circuit. The wheel sensor induction module is connected to the acquisition input end of the AD acquisition module through an analog signal output circuit. The output end of the AD acquisition module is connected to the input end of the FPGA chip. The output end of the FPGA chip is connected to the input end of the amplification circuit. The amplification circuit is connected to the railway 5T system through a digital signal output circuit. The wheel sensor induction module is a permanent magnet component formed by combining two split permanent magnets. The permanent magnet is mainly composed of a magnet iron core and an induction wire coil.

[0012] As one of the preferred ways, the wheel sensor induction module is one group.

[0013] As one of the preferred ways, the wheel sensor induction module is two groups, and the two groups of wheel sensor induction modules share one digital signal processing board.

[0014] As one of the preferred embodiments, there are two sets of wheel sensor induction modules. Each set of wheel sensor induction modules has its own digital signal processing board, and the two digital signal processing boards are connected to the railway 5T system through their respective digital signal output circuits.

[0015] As one of the preferred embodiments, the magnet assembly includes two split magnets and a fixed base. The two split magnets are respectively fixed at both ends of the fixed base, and the distance between the two split magnets is fixed at d; d = 250mm - 270mm.

[0016] As one of the preferred embodiments, the magnet is mainly composed of a first magnet iron core and a first induction wire coil, and the winding direction of the first magnet iron core is perpendicular to that of the first induction wire coil.

[0017] As one of the preferred embodiments, the magnet is mainly composed of a second magnet iron core and a second induction wire coil, and the winding direction of the second magnet iron core is parallel to that of the second induction wire coil.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows: A digital wheel sensor has the following advantages:

[0019] Converts the analog signal output by the magnet into a digital signal. The digital signal can be fully received, the signal is stable, and the existing interference signals have no influence on it, making the detection results of the later railway vehicle bottom detection system more accurate;

[0020] Combines the two split magnets together, fixes the distance, and thus maintains the best signal effect;

[0021] The two split magnets can share a digital circuit board, reducing costs and obtaining more accurate digital signals. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the principle of the digital wheel sensor of the present utility model.

[0023] Figure 2 It is a schematic diagram of the principle of the wheel sensor when there are two sets of magnet assemblies.

[0024] Figure 3 It is a simplified structural diagram of a single magnet.

[0025] Figure 4 It is a simplified structural diagram of another form of a single magnet.

[0026] Figure 5 It is a simplified structural diagram when two magnets are combined into a magnet assembly.

[0027] Figure 6It is a simplified connection diagram of a magnetic steel component with two digital signal processing boards.

[0028] Figure 7 It is a simplified connection diagram of a magnetic steel component sharing a digital signal processing board.

[0029] Figure 8 It is a waveform schematic diagram of an analog signal in the prior art.

[0030] Figure 9 It is a waveform schematic diagram of the digital signal of the present utility model.

[0031] In the attached drawings: wheel sensor induction module 1, wheel sensor first induction module 11, wheel sensor second induction module 12, digital signal processing board 3, power supply 4, analog signal output circuit 5, AD acquisition module 6, FPGA chip 7, amplification circuit 8, digital signal output circuit 9, railway 5T system 10; first induction wire coil L1, first magnet iron core 101, second induction wire coil L2, second magnet iron core 102, fixed base 103. d: the distance between two magnetic steels in the fixed base. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0033] Embodiment 1

[0034] As Figure 1 shown, a digital wheel sensor includes a wheel sensor induction module 1 and a digital signal processing board 3. Among them, the digital signal processing board 3 includes an AD acquisition module 6, an FPGA chip 7, and an amplification circuit 8. The wheel sensor induction module 1 is connected to the acquisition input end of the AD acquisition module 6 through an analog signal output circuit 5. The output end of the AD acquisition module 6 is connected to the input end of the FPGA chip 7. The output end of the FPGA chip 7 is connected to the input end of the amplification circuit 8. The amplification circuit 8 is connected to the railway 5T system 10 through a digital signal output circuit 9. The power supply 4 supplies power to the digital signal processing board 3 and the railway 5T system 10. The power supply 4 can be a battery or an external power cord. Among them, as Figure 3 shown, the wheel sensor induction module 1 is a single magnetic steel. The magnetic steel is mainly composed of a first magnet iron core 101 and a first induction wire coil L1. The first magnet iron core 101 is perpendicular to the winding direction of the first induction wire coil L1.

[0035] The present utility model can render existing interference signals ineffective, mainly because: as Figure 9 shown, the digital signal is equivalent to a generated DC voltage, while the signal generated by the interference source belongs to an AC voltage, and the AC voltage no longer affects the DC voltage of the digital signal. In the FPGA chip of the digital signal processing board, a series of AI algorithms are preset in advance. The AI algorithms remove the interference signals of the magnet and the coil itself, and at the same time filter out the magnitude of the interference signals through the AI algorithms. The existing output analog signals have certain requirements for the backend processor. Especially for some analog signals with weak signals, they will be missed if not received. Now, the digital signal output can stabilize its magnitude, and only requires the backend processor to be able to receive it, thus reducing the requirements for the backend processor.

[0036] Processing process of the digital signal processing board:

[0037] The AD acquisition module converts the analog signal into a digital signal. In the AD acquisition module, through the soft processing of the AD-acquired data, the influence of interference signals is minimized, and acquisition filtering is performed on data acquisition. Currently, there are many methods for data acquisition filtering. Here, the limit filtering method, or the median filtering method, etc. can be used.

[0038] Limit filtering method:

[0039] First, based on experience judgment, determine the maximum allowable deviation value of two samplings (set as A)

[0040] Each time a new value is detected, make the following judgment:

[0041] If the difference between the current value and the previous value < or = A, then the current value is valid;

[0042] If the difference between the current value and the previous value > A, then the current value is invalid, and it needs to be discarded. Use the previous value to replace it and continue the judgment.

[0043] Even though acquisition filtering is performed on the AD acquisition, the AD acquisition still converts the acquired magnet signals and interference signals into digital signals together. The converted digital signal is processed by the FPGA chip (PGA (Field-Programmable Gate Array), that is, the field programmable gate array) with a corresponding program pre-written in advance. Here, the processing method for interference signals is pre-written in advance, especially for the identification and filtering of interference signals, and the identification and output of useful normal signals are also pre-written. Even if the interference signal source is dynamically changing, due to the identification of interference signals by the FPGA, the interference signals can be effectively excluded.

[0044] After processing, only the normal signal remains in the digital signal. The normal signal is amplified in power through an amplifier circuit to facilitate subsequent processing. The normal digital signal is then transmitted to the receiving end through a digital signal output circuit. Here, the receiving end is the railway 5T system. Due to the output digital signal, in the railway 5T system, compared with the existing receiving device circuit board, some settings can be simplified. Other systems can be any other terminal devices.

[0045] Embodiment 2

[0046] As Figure 1 shown, a digital wheel sensor includes a wheel sensor induction module 1 and a digital signal processing board 3. The digital signal processing board 3 includes an AD acquisition module 6, an FPGA chip 7, and an amplifier circuit 8. The wheel sensor induction module 1 is connected to the acquisition input end of the AD acquisition module 6 through an analog signal output circuit 5. The output end of the AD acquisition module 6 is connected to the input end of the FPGA chip 7. The output end of the FPGA chip 7 is connected to the input end of the amplifier circuit 8. The amplifier circuit 8 is connected to the railway 5T system 10 through a digital signal output circuit 9; the power supply 4 supplies power to the digital signal processing board 3 and the railway 5T system 10. The power supply 4 can be a battery or an external power cord.

[0047] Among them, as Figure 5 shown, the wheel sensor induction module is a magnet assembly formed by combining two split magnets into one. The magnet assembly includes two split magnets 2 and a fixed base 103. The two split magnets 2 are respectively fixed at both ends of the fixed base 103. The distance between the two split magnets 2 is fixed at d; d = 250 mm - 270 mm. In this embodiment, d = 270 mm. As Figure 4 shown, the magnet is mainly composed of a second induction wire coil L2 and a second magnet iron core 102. The winding direction of the second induction wire coil L2 is parallel to that of the second magnet iron core 102. Fixing two independent split magnets on the fixed base reduces the trouble of aligning the optimal distance between the two magnets during installation, and during use, the distance between the two magnets can always remain unchanged, reducing the influence of distance changes on this component.

[0048] Embodiment 3

[0049] As Figure 2As shown in the figure, a digital wheel sensor includes a wheel sensor induction module and a digital signal processing board 3. The digital signal processing board 3 includes an AD acquisition module 6, an FPGA chip 7, and an amplification circuit 8. The wheel sensor induction module 1 is connected to the acquisition input end of the AD acquisition module 6 through an analog signal output circuit 5. The output end of the AD acquisition module 6 is connected to the input end of the FPGA chip 7. The output end of the FPGA chip 7 is connected to the input end of the amplification circuit 8. The amplification circuit 8 is connected to the railway 5T system 10 through a digital signal output circuit 9. The power supply 4 supplies power to the digital signal processing board 3 and the railway 5T system 10. The power supply 4 can be a battery or an external power cord.

[0050] Among them, as Figure 6 shown in the figure, there are two groups of wheel sensor induction modules, namely the first wheel sensor induction module 11 and the second wheel sensor induction module 12. The first wheel sensor induction module 11 can be a single magnetic steel or a magnetic steel component formed by combining two split magnetic steels into one. Similarly, the second wheel sensor induction module 12 can also be a single magnetic steel or a magnetic steel component formed by combining two split magnetic steels into one. The first wheel sensor induction module 11 and the second wheel sensor induction module 12 each have their own digital signal processing board 3. The first wheel sensor induction module 11 and the second wheel sensor induction module 12 are connected to their respective digital signal processing boards 3 through their respective analog signal output circuits 5. The two digital signal processing boards 3 are connected to the railway 5T system 10 through their respective digital signal output circuits 9.

[0051] Embodiment 4

[0052] As Figure 2 shown in the figure, a digital wheel sensor includes a wheel sensor induction module and a digital signal processing board 3. The digital signal processing board 3 includes an AD acquisition module 6, an FPGA chip 7, and an amplification circuit 8. The wheel sensor induction module 1 is connected to the acquisition input end of the AD acquisition module 6 through an analog signal output circuit 5. The output end of the AD acquisition module 6 is connected to the input end of the FPGA chip 7. The output end of the FPGA chip 7 is connected to the input end of the amplification circuit 8. The amplification circuit 8 is connected to the railway 5T system 10 through a digital signal output circuit 9. The power supply 4 supplies power to the digital signal processing board 3 and the railway 5T system 10. The power supply 4 can be a battery or an external power cord.

[0053] Among them, as Figure 7As shown in the figure, there are two groups of wheel sensor induction modules, namely the first wheel sensor induction module 11 and the second wheel sensor induction module 12. The first wheel sensor induction module 11 can be a single magnetic steel or a magnetic steel component formed by combining two split magnetic steels into one; similarly, the second wheel sensor induction module 12 can also be a single magnetic steel or a magnetic steel component formed by combining two split magnetic steels into one. The first wheel sensor induction module 11 and the second wheel sensor induction module 12 share a digital signal processing board 3. The first wheel sensor induction module 11 and the second wheel sensor induction module 12 input analog signals to the digital signal processing board through the analog signal output circuit 5. The two groups of signals are simultaneously sampled and processed in the digital signal processing board, and then the digital signal processing board 3 is connected to the railway 5T system 10 through the digital signal output circuit 9.

[0054] The induction wire coil in the magnetic steel described in the above embodiment is a bipolar single coil. Bipolar means N pole and S pole. The bottom of the U-shaped magnetic body bracket is made of ferromagnetic material with magnetic conductivity, and the two sides are permanent magnets. The winding direction of the bipolar single coil is parallel to the direction of the magnetic field induced by the interference of the railway power line. After installation, the lead-out wire is connected and assembled with the waterproof electrical socket on the side or back of the insulating shell of the wheel sensor or the cable wire is led out through a nylon quick connector. The manufacturing methods and processes of each component are the same as those of the existing coil.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A digital wheel sensor, comprising a wheel sensor sensing module and a digital signal processing board, characterized in that: The digital signal processing board includes an AD acquisition module, an FPGA chip and an amplifying circuit. The wheel sensor sensing module is connected to the acquisition input end of the AD acquisition module through an analog signal output circuit, the output end of the AD acquisition module is connected to the input end of the FPGA chip, the output end of the FPGA chip is connected to the input end of the amplifying circuit, and the amplifying circuit is connected to the railway 5T system through a digital signal output circuit; the wheel sensor sensing module is a magnetic steel component composed of two split magnetic steels combined into one, and the magnetic steel is mainly composed of a magnet core and an induction wire package.

2. The digital wheel sensor according to claim 1, characterized in that: The wheel sensor sensing module is a set.

3. The digital wheel sensor according to claim 1, characterized in that: There are two groups of wheel sensor sensing modules, and the two groups of wheel sensor sensing modules share a digital signal processing board.

4. The digital wheel sensor according to claim 1, characterized in that: There are two groups of wheel sensor sensing modules, each of which has an independent digital signal processing board. The two digital signal processing boards are connected to the railway 5T system through their own digital signal output circuits.

5. The digital wheel sensor according to claim 1, characterized in that: The magnetic steel assembly includes two split magnetic steels and a fixed base. The two split magnetic steels are respectively fixed at two ends of the fixed base. The distance between the two split magnetic steels is fixed to d; d=250mm-270mm.

6. The digital wheel sensor according to claim 1, characterized in that: The magnetic steel is mainly composed of a No. 1 magnet core and a No. 1 induction coil, and the No. 1 magnet core and the No. 1 induction coil are arranged perpendicularly to the winding direction.

7. The digital wheel sensor according to claim 6, characterized in that: The magnetic steel is mainly composed of a No. 2 magnetic core and a No. 2 induction coil, and the No. 2 magnetic core is arranged in parallel with the winding direction of the No. 2 induction coil.

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