CN101734172B - Magnetic suspension train suspension spacing sensor capable of compensating slot effect - Google Patents

Abstract

A levitation distance sensor for maglev trains capable of compensating cogging effect, the probe coil is composed of a displacement detection coil and a compensation coil, wherein the displacement detection coil is composed of two identical 8-shaped detection coils arranged side by side along the track, Two rectangular coils with the same size and opposite winding directions are also arranged along the transverse direction of the track. The width of the detection coil along the longitudinal direction of the track is the length D of the track cogging unit; there are two pairs of compensation coils, and the two pairs of compensation coils are staggered along the longitudinal direction of the track by 1/ 4 The cogging unit length D, a pair of compensation coils are superimposed within the range of a corresponding detection coil; each pair of compensation coils is composed of two columns of compensation coils whose longitudinal distance along the track is 1/2 the cogging unit length D. The sensor can compensate the cogging effect, and the detected levitation distance is accurate, reliable and has high precision.

Description

A levitation distance sensor for maglev trains capable of compensating cogging effect

technical field

The invention relates to a non-contact distance sensor for the suspension distance of a maglev vehicle.

Background technique

The non-contact displacement sensor (spacing sensor) of the suspension distance of the existing maglev vehicle is based on the principle of electromagnetic induction to realize the measurement of the distance. Detection of suspension distance.

There are many types of non-contact displacement sensors based on the principle of electromagnetic induction. The working principle of one type of inductive non-contact displacement sensor is: when there is a metal object near the energized sensor detection coil (probe coil), due to the change of the metal object The reluctance of the induced electromagnetic field magnetic circuit generated by the detection coil can affect the inductance of the coil, so the inductance of the coil is related to the distance between the coil and the metal body, and the relationship is L=N ² μS/2δ, where N is the number of turns of the coil; μ is the air permeability; S is the area surrounded by the coil; δ is the distance between the coil and the surface of the metal body to be detected. Among them, the magnetic permeability μ of air is a constant, and N and S are fixed values after the coil is wound. Therefore, the inductance L of the coil is inversely proportional to the distance value δ between the detection coil and the surface of the metal body.

During detection, a high-frequency signal source feeds a high-frequency AC signal to the detection coil, and the high-frequency signal generates an induced electromotive force in the detection coil. The magnitude of the induced electromotive force is related to the inductance of the coil, and the detection device measures the induced electromotive force. The magnitude of the formed voltage signal can be used to obtain the distance δ between the detection coil and the surface of the metal body to be tested.

According to the analysis of the above working principle, when using the inductive non-contact displacement sensor to measure distance, the surface of the metal body to be detected is required to be a standard plane shape. If the surface of the metal body to be detected is uneven, the output of the detection device will produce errors. , making the measurement results inaccurate.

High-speed maglev trains are developing rapidly. In order to ensure the normal operation of high-speed maglev trains, it is necessary to control the vertical distance between the train and the track, which is usually measured by inductive displacement sensors. However, because the track of the high-speed maglev train is a long stator track with alternating teeth and slots, the teeth on the track are all metal bodies, and the slots are slots opened on the metal body, and cables are wound in the slots. When the inductive displacement sensor is in the long When moving on the surface of the stator track, the output value will change with the periodic change of the track cogging, the so-called cogging effect occurs, and the measurement error of the vertical spacing value (also called cogging error) occurs. This cogging The error makes the detection output value inaccurate, which cannot meet the requirements of real-time and precise control of high-speed maglev vehicles to ensure that the suspension distance is high-precision and consistent.

Contents of the invention

The object of the present invention is to provide a levitation distance sensor for maglev trains capable of compensating for cogging effect. The sensor can compensate for cogging effect, and the detected levitation distance is accurate, reliable and high in precision.

The present invention realizes its object of the invention, and the adopted technical scheme is: a kind of maglev train levitation distance sensor that can compensate cogging effect, comprises the probe coil that links to each other with the high-frequency signal source on the car body, and the probe coil is also connected with the signal processing circuit Its structural characteristics are: the probe coil is composed of a displacement detection coil and a compensation coil,

The displacement detection coil is composed of two identical 8-shaped detection coils arranged laterally along the track, and each detection coil is composed of two rectangular coils of equal size and opposite winding directions connected in series, and are also arranged along the lateral direction of the track. The width of the detection coil along the longitudinal direction of the track is the length D of the track cogging unit;

There are two pairs of compensation coils, and the two pairs of compensation coils are staggered by 1/4 of the cogging unit length D along the track longitudinally, and a pair of compensation coils are superimposed within the range of a corresponding detection coil; It is composed of two columns of compensation coils with a length D of 1/2 slot unit, and each column of compensation coils is composed of four equal-sized rectangular small coils arranged laterally along the track, and any adjacent small coils in each column of coils The direction of current in is opposite.

The working principle of the present invention is:

When the maglev train is moving, the probe coil installed on the maglev vehicle also travels along the longitudinal direction of the track with the car body, and at the same time detects the vertical distance between the maglev vehicle and the track:

Two independent displacement detection coils detect the vertical distance between the car body and the track, and obtain two independent distance values, and since the width of the detection coil along the longitudinal direction of the track is the length D of the track cogging unit; therefore, the two A pitch value contains a cogging error that is consistent with the change law of the orbital cogging period.

The distance between the two columns of coils in each pair of compensation coils along the longitudinal direction of the track is 1/2 the length of the slot unit D, so the phase difference of the induced electromotive force generated by the two columns of coils is 180°. In the signal processing circuit, the same pair of The phase difference of the two columns of coils in the compensation coil is subtracted from the two sine wave (induced electromotive force) signals to remove the DC component and output a pure AC sine wave signal; at the same time, since the two pairs of compensation coils along the track The length D of the cogging unit is staggered longitudinally by 1/4, so the phase difference of the pure AC sine wave signals output by the two pairs of coils is 90°. In the signal processing circuit, the trigonometric function operation is performed on the two pure AC sinusoidal signals with a phase difference of 90°, and the phase value of the current position can be obtained, and the vertical distance of the cogging corresponding to the current position can be obtained from the phase value compensation value.

The two spacing values obtained by the detection coil and the spacing compensation value obtained by the compensation coil are analyzed and diagnosed by the signal processing circuit; the two spacing values plus the spacing compensation value are output as two independent spacing detection values. At the same time, the two compensated spacing values are diagnosed. If the difference between the two spacing values is greater than the set threshold, it indicates that at least one of the two detection coils is working in an abnormal state. At this time, the diagnostic circuit will generate a fault alarm signal. .

Compared with prior art, the beneficial effect of the present invention is:

1. Two columns of compensation coils with a difference of 1/2 the length of the cogging unit form a pair of compensation coils, and the difference between the two pairs of compensation coils is 1/4 the length of the cogging unit, so that after the calculation of the output signals of these compensation coils, it can be The position (phase) of the detection coil in the cogging unit is measured, and the detection value of the detection coil is compensated according to different vertical distance compensation values corresponding to different positions, and then output. The error caused by the cogging effect is eliminated, the detection result is reliable, the precision is high, and the high-speed maglev train can meet the precise and constant control requirements of the levitation distance (vertical distance).

2. Use two displacement detection coils for detection, and carry out diagnostic processing on the detection results to ensure the reliability of the detection results: when the detection coil fails or is misdetected due to various factors, the difference between the output values of the two detection coils is too large Large, the system will generate an alarm signal to avoid serious adverse consequences and ensure the high reliability of the levitation distance detection of the maglev vehicle to further ensure the operation safety of the maglev train.

3. The displacement detection coil is formed by connecting two rectangular coils with equal size and opposite directions on the left and right to form a figure-eight shape. Since the induced electromotive force generated by the outward magnetic field in this coil is equal in size and opposite in direction, it can be offset, so , can overcome the influence of the external magnetic field on its detection coil. Similarly, each column of compensation coils is composed of four equal-sized small coils arranged laterally along the track, and the current direction in any adjacent small coils in each column of coils is opposite; in this way, the compensation coils will not Introducing magnetic field interference to the displacement detection coil can also resist the influence of the external magnetic field on itself. The sensor of the present invention is especially suitable for the environment of strong external magnetic field such as the magnetic levitation vehicle.

The above-mentioned way that the probe coil is connected to the high-frequency signal source is: the frequencies of the two high-frequency signal sources connected to the two displacement detection coils in the probe coil are different, and the frequency of the high-frequency signal source connected to the compensation coil is the same as any displacement The frequency of the high-frequency signal source of the detection coil is also different.

The high-frequency signal sources connected to the above two displacement detection coils are independent, and the high-frequency signal sources connected to the compensation coil are also independent high-frequency signal sources.

In this way, it is beneficial to the independent extraction of the induced electromotive force electric signal, reduces mutual interference, and improves the precision and accuracy of the detection result.

The specific structure that the above-mentioned probe coil is connected with the signal processing circuit is: each displacement detection coil is connected with the corresponding displacement signal processing unit and compensation calculation unit in turn to form a group of independent detection circuits; the compensation coils are connected with the independent compensation signal processing unit The units are connected, and the output end of the compensation signal processing unit is connected to the two compensation operation units at the same time; the output ends of the two compensation operation units are also connected to the input end of the diagnosis signal processing unit.

Like this, combine two independent high-frequency signal sources that two displacement detection coils are respectively connected, the present invention has two independent high-frequency signal sources, signal detection, processing and output circuit, guarantees that the detection output value is redundant two-way Independent output value. In addition, the diagnostic signal processing unit can compare the two independent output values to determine whether the detection circuit is faulty, and the diagnostic signal processing unit outputs the judgment result to further ensure the reliability of the sensor output results.

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

FIG. 1 is a schematic diagram of the arrangement of various coils and their electrical principles according to an embodiment of the present invention. The direction of the small solid arrow on the coil is the direction of the feeding current, and the direction of the large hollow arrow is the longitudinal direction of the track.

Fig. 2 is a schematic diagram of the electrical principle structure of the embodiment of the present invention.

Detailed ways

Fig. 1 and Fig. 2 show that a kind of embodiment of the present invention is: a kind of maglev train levitation distance sensor that can compensate cogging effect, comprises the probe coil that links to each other with the high-frequency signal source on the car body, probe coil also Connected to the signal processing circuit. The probe coil is composed of a displacement detection coil and a compensation coil.

The displacement detection coil is composed of two identical 8-shaped detection coils La and Lb arranged laterally along the track, and each detection coil La or Lb is composed of two rectangular coils of equal size and opposite winding directions connected in series, and also Arranged along the transverse direction of the track, the width of the detection coils La and Lb along the longitudinal direction of the track is the length D of the track cogging unit;

There are two pairs of compensation coils, the two pairs of compensation coils L1, L2 and L3, L4 are longitudinally staggered by 1/4 of the cogging unit length D along the track, and a pair of compensation coils L1, L2 or L3, L4 is superimposed on a corresponding detection coil La or within the range of Lb; each pair of compensation coils L1, L2 or L3, L4 is composed of two columns of compensation coils L1, L2 or L3, L4 whose longitudinal distance along the track is 1/2 cogging unit length D, and each column compensates The coils L1, L2, L3 or L4 are connected by four small rectangular coils of equal size arranged laterally along the track, and the current directions in any adjacent small coils in each row of coils are opposite. That is to say, if the direction of the current in each part of a certain small coil forms a circle of counterclockwise direction, then the current flowing in each place of the adjacent small coil must form a circle of clockwise direction.

Figure 2 also shows:

The way in which the probe coil is connected to the high-frequency signal source in this example is: the frequencies of the two high-frequency signal sources Sa and Sb connected to the two displacement detection coils La and Lb in the probe coil are different (that is, the displacement detection coil La is connected to the corresponding The high-frequency signal source Sa, the displacement detection coil Lb is correspondingly connected to the high-frequency signal source Sb, the frequencies of the high-frequency signal source Sa and the high-frequency signal source Sb are different), the high-frequency signal source Sc connected to the compensation coils L1, L2, L3 and L4 The frequency is also different from the frequency of the high-frequency signal source Sa or Sb of any displacement detection coil La or Lb.

The high-frequency signal sources Sa and Sb connected to the two displacement detection coils La and Lb in this example are independent, and the high-frequency signal sources Sc connected to the compensation coils L1, L2, L3 and L4 are also independent high-frequency signal sources.

The specific structure of the connection between the probe coil and the signal processing circuit in this example is: each displacement detection coil La or Lb is sequentially connected with the corresponding displacement signal processing unit A or B, and the compensation operation unit Pa or Pb to form a set of independent detection circuits (That is, the displacement detection coil La is sequentially connected to the corresponding displacement signal processing unit A and the compensation operation unit Pa to form a set of independent detection circuits, and the displacement detection coil Lb is connected to the corresponding displacement signal processing unit B and the compensation operation unit Pb in sequence, constitute another group of independent detection circuits); the compensation coils L1, L2, L3 and L4 are all connected to an independent compensation signal processing unit C, and the output end of the compensation signal processing unit C is simultaneously connected to two compensation operation units Pa and Pb; The output terminals of the two compensation calculation units Pa and Pb are also connected to the input terminal of the diagnostic signal processing unit Z. All these signal processing units and diagnosis processing units constitute a signal processing circuit.

Claims (4)

1. magnetic floating train suspending pitch sensors that can compensate slot effect, comprise the probe coil that links to each other with high-frequency signal source on the car body, probe coil also links to each other with signal processing circuit, it is characterized in that: described probe coil is made up of displacement detector coil and compensating coil

Wherein displacement detector coil is magnetic test coil (La, the Lb) formation along horizontal two the identical eight shapes side by side of track, each magnetic test coil (La, Lb) is by two equal and opposite in directions, around being connected in series to opposite square coil, and also arrange along the track horizontal direction, two magnetic test coils (La, Lb) are track teeth groove element length D along the width of track longitudinal direction;

Described compensating coil is two pairs, two pairs of compensating coils (L1, L2, L3, L4) are along the track 1/4 teeth groove element length D that vertically staggers, in the scope of the superimposed magnetic test coil (La) in described two magnetic test coils of a pair of compensating coil (L1, L2), in another scope to superimposed another magnetic test coil (Lb) in described two magnetic test coils of compensating coil (L3, L4); Every pair of compensating coil (L1, L2, L3, L4) is again by forming apart from the two row compensating coils (L1, L2, L3, L4) that are 1/2 teeth groove element length D longitudinally along track, every row compensating coil (L1, L2, L3, L4) is then by connecting and composing along four transversely arranged equal-sized rectangle small coils of track, and the current opposite in direction in any adjacent small coil in every row compensating coil.

2. a kind of magnetic floating train suspending pitch sensors that can compensate slot effect according to claim 1, it is characterized in that: the mode that described probe coil and high-frequency signal source link to each other is: a magnetic test coil (La) and corresponding connection of first high-frequency signal source (Sa) in two magnetic test coils, another magnetic test coil (Lb) and the corresponding connection of second high-frequency signal source (Sb) in two magnetic test coils, every row compensating coil (L1, L2, L3, L4) all is connected with the 3rd high-frequency signal source (Sc); The frequency of first high-frequency signal source (Sa), second high-frequency signal source (Sb), the 3rd high-frequency signal source (Sc) is all inequality.

3. a kind of magnetic floating train suspending pitch sensors that can compensate slot effect according to claim 2, it is characterized in that: the corresponding bonded assembly high-frequency signal sources of described two magnetic test coils (La, Lb) (Sa, Sb) are independent separately, and compensating coil (L1, L2, L3, L4) bonded assembly high-frequency signal source (Sc) also is high-frequency signal source independently.

4. a kind of magnetic floating train suspending pitch sensors that can compensate slot effect according to claim 1, it is characterized in that: the concrete structure that described probe coil links to each other with signal processing circuit is: each magnetic test coil (La, Lb) links to each other successively with corresponding displacement signal processing unit (A, B), compensation operation unit (Pa, Pb), constitutes one group of independently testing circuit; Every row compensating coil (L1, L2, L3, L4) all with one independently compensating signal processing unit (C) link to each other, the mouth of compensating signal processing unit (C) links to each other with two compensation operation unit (Pa, Pb) simultaneously; The mouth of two compensation operation unit (Pa, Pb) also all links to each other with the input end of a diagnostic signal processing unit (Z).

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