CN116182765A - Self-calibration control method and device of displacement sensor based on magnetic suspension bearing - Google Patents

Abstract

The invention relates to a self-calibration control method and a self-calibration control device of a displacement sensor based on a magnetic suspension bearing, belonging to the technical field of displacement sensor calibration; the self-calibration control method comprises the following steps: acquiring and processing the displacement signal output by the displacement sensor and the operation parameters of the magnetic suspension system; performing equipment self-checking on the magnetic suspension system based on the processed data, and starting and operating the equipment when the equipment self-checking is qualified; and when the self-check of the equipment is abnormal, self-calibrating the displacement sensor by adopting a self-calibrating algorithm. According to the self-calibration control method and device for the displacement sensor based on the magnetic suspension bearing, when the state of the magnetic suspension system is abnormal, the self-calibration algorithm is called, and before the magnetic suspension device actually operates, the magnetic suspension bearing is used for controlling the relative position of the suspension object, so that the maximum movable range of the suspension object is obtained, the device automatically calibrates the displacement sensor, the stable operation of the device is ensured, the service life of the device is prolonged, and the maintenance cost is reduced.

Description

Self-calibration control method and device of displacement sensor based on magnetic suspension bearing

Technical Field

The invention relates to a self-calibration control method and device of a displacement sensor based on a magnetic suspension bearing, and belongs to the technical field of displacement sensor calibration.

Background

Related equipment of the magnetic suspension motor, such as a magnetic suspension blower, a magnetic suspension compressor, a magnetic suspension pump, a magnetic suspension energy storage flywheel, a magnetic suspension electric main shaft and the like, has no contact and friction between a rotating part mechanism and a magnetic suspension bearing, can always achieve higher rotating speed during actual operation, has obvious energy-saving effect, is gradually widely applied to the market at present, and is gradually popularized in various application scenes in the industrial field in the future.

The principle of non-contact between the rotor and the bearing of the magnetic suspension motor is as follows: the exciting current in the magnetic suspension bearing coil generates magnetic force to suspend the rotor in the middle of the bearing, the displacement deviation of the rotor is detected by the displacement sensor, the magnitude of the exciting current is regulated by the electric control system, and then the stable suspension of the rotor is controlled, so that the magnetic suspension bearing is essentially an electromagnet with the relative position regulated by negative feedback.

The bearing capacity of the electromagnet is proportional to the square of the current and inversely proportional to the square of the gap, so that the bearing capacity of the magnetic suspension bearing is ensured to be large enough, the gap is often small, the corresponding displacement sensor is small in testing gap and measuring range, and the precision requirement is extremely high.

In the actual use process of the magnetic suspension motor equipment, parts of components of the displacement sensor system are aged to a certain extent along with the lengthening of the service time, so that a small amount of change of output signals of the displacement sensor under the same working condition, namely so-called time drift, is generated; the position of the sensor changes along with the temperature, so that the output signal changes under the same working condition, namely the temperature drift; there is little change and relative positional shift in the internal structure of the probe and the fixed support under the environment of long-term vibration.

The magnetic suspension motor product has wide application range, most of the operation environments are relatively bad, and the three conditions are often unavoidable in magnetic suspension motor equipment, so that the sensor system needs to be calibrated after being used for a certain time, and the measurement accuracy is ensured. However, the overall maintenance cost is high because the magnetic levitation devices are often sold around the world.

Therefore, for those skilled in the art, there is a need for a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, so that the device can automatically complete the calibration of the sensor according to different conditions, thereby prolonging the service life of the device and reducing the maintenance cost of the device.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the self-calibration control method and the self-calibration control device of the displacement sensor based on the magnetic suspension bearing, when the state of the magnetic suspension system is abnormal, the self-calibration algorithm in the magnetic suspension control module is called, and the relative position of a suspension object is controlled by the magnetic suspension bearing before the actual operation of the magnetic suspension device, so that the maximum movement range of the suspension object is obtained, the device can calibrate the displacement sensor in the magnetic suspension system automatically, the long-term high-precision stable operation of the device is ensured, the service life of the device is prolonged, and the maintenance cost is reduced.

The technical scheme of the invention is as follows:

the self-calibration control method of the displacement sensor based on the magnetic suspension bearing comprises the following steps:

acquiring a displacement signal output by a displacement sensor and operating parameters of a magnetic suspension system;

processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

performing equipment self-checking on the magnetic suspension system based on the processed data, and starting and operating the equipment when the equipment self-checking is qualified; when the self-check of the equipment is abnormal, self-calibrating the displacement sensor by adopting a self-calibrating algorithm;

the self-calibration algorithm includes: increasing exciting current of an electromagnet in the magnetic suspension bearing, wherein the exciting current can generate acting force in positive/negative directions of an x axis, a y axis or a z axis, and reducing the exciting current of the electromagnet in the magnetic suspension bearing, wherein the acting force can be generated in other directions, to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration.

According to the invention, the operating parameters of the magnetic levitation system preferably comprise one or more of the following: the method comprises the following steps of (1) exciting current of a magnetic suspension bearing during static suspension of a magnetic suspension system, temperature of the magnetic suspension bearing, starting time of the magnetic suspension system and exciting current of the magnetic suspension bearing during operation of the magnetic suspension system.

According to the invention, preferably, the self-checking of the device for the presence of anomalies comprises:

when the magnetic suspension system is in static suspension, the exciting current of the magnetic suspension bearing is smaller than a first set value, and a suspension object cannot be suspended;

when the magnetic suspension system is in static suspension, the difference value between the temperature of the magnetic suspension bearing and the temperature of the magnetic suspension bearing at the last starting exceeds a second set value;

when the magnetic suspension system is in static suspension, the time interval between the starting time of the magnetic suspension system and the starting time of the last magnetic suspension system is larger than a third set value;

when the magnetic suspension system runs last time, the exciting current of the magnetic suspension bearing exceeds a fourth set value;

other magnetic levitation devices may have anomalies or malfunctions.

According to the invention, the magnetic levitation system is preferably a rotary magnetic levitation device, in which a magnetic levitation motor is taken as an example, and a rotor of the motor is taken as a levitation object;

The rotary magnetic suspension device is provided with a group of radial magnetic suspension bearings and a group of axial magnetic suspension bearings, the group of radial magnetic suspension bearings are sleeved outside the rotor, and the group of axial magnetic suspension bearings are arranged on two sides of the thrust disc or the shaft shoulder of the rotor; six degrees of freedom are respectively translational motion along an x axis, a y axis and a z axis and rotation around the x axis, the y axis and the z axis under a three-dimensional space coordinate system, the radial magnetic suspension bearing is used for restraining the rotor to translate along the radial x axis or the y axis and rotate around the x axis or the y axis, and the axial magnetic suspension bearing is used for restraining the rotor to translate along the z axis;

the radial magnetic suspension bearing comprises four electromagnets, wherein two electromagnets are oppositely arranged on an x axis or a y axis respectively, and the two electromagnets on the same coordinate axis are controlled in a differential mode, and the two electromagnets on the same coordinate axis jointly control one degree of freedom;

two axial magnetic suspension bearings are oppositely arranged on the z-axis, the two axial magnetic suspension bearings on the same coordinate axis are controlled in a differential mode, and the two axial magnetic suspension bearings jointly control one degree of freedom;

each electromagnet in the radial magnetic suspension bearing is correspondingly provided with a displacement sensor, the distribution mode of a probe of the displacement sensor is consistent with that of the electromagnet, and the two displacement sensors on the same coordinate axis are controlled in a differential mode;

The axial magnetic suspension bearing is provided with two displacement sensors, and the two displacement sensors are controlled in a differential mode.

The differential control method can improve the detection precision of the sensor and reduce the influence caused by temperature drift.

According to the present invention, preferably, in the case where the magnetic levitation system is a rotary magnetic levitation device, the self-calibrating the displacement sensor when the self-checking of the device is abnormal includes:

the self-calibration mode of the radial magnetic suspension bearing matched displacement sensor is as follows:

synchronously increasing exciting currents of electromagnets capable of generating positive/negative direction acting forces of a Y axis in a group of radial magnetic suspension bearings, reducing the exciting currents of electromagnets capable of generating other direction acting forces in the radial magnetic suspension bearings to 0, obtaining the maximum movable range of a rotor in the positive/negative direction of the Y axis, and calibrating the output value of a corresponding displacement sensor module to be X1/Y1;

thereby determining that the rotor moves within the maximum movable range in the positive/negative direction of the Y-axis, and the output value of the displacement sensor module is within the interval [ X1, Y1 ]; when the rotor is suspended in the middle of the maximum movable range in the Y-axis direction, the output value of the corresponding displacement sensor module is (X1 +Y1)/2;

synchronously increasing exciting currents of electromagnets capable of generating positive/negative direction acting forces of an X axis in a group of radial magnetic suspension bearings, reducing the exciting currents of electromagnets capable of generating other direction acting forces in the radial magnetic suspension bearings to 0, obtaining the maximum movable range of a rotor in the positive/negative direction of the X axis, and calibrating the output value of a corresponding displacement sensor module to be X2/Y2;

Thereby judging that the rotor moves in the maximum movable range in the positive/negative direction of the X-axis, and the output value of the corresponding displacement sensor module is in the interval [ X2, Y2 ]; in a static suspension state of the magnetic suspension system, when the rotor is suspended in the middle of the maximum movable range in the X-axis direction, the output value of the corresponding displacement sensor is (X < 2+Y < 2 >)/2;

the self-calibration mode of the axial magnetic suspension bearing matched displacement sensor is as follows:

increasing exciting current of an axial magnetic suspension bearing capable of generating positive/negative direction acting force of a z axis, reducing exciting current of the other axial magnetic suspension bearing to 0 at the same time, obtaining the maximum movable range of a rotor in the positive/negative direction of the z axis, and calibrating the output value of a displacement sensor module in the positive/negative direction of the z axis to be X3/Y3;

thereby determining that the rotor moves within the maximum movable range in the positive/negative direction of the z-axis, and the output value of the displacement sensor module is within the interval [ X3, Y3 ]; in the static suspension state of the magnetic suspension system, when the rotor is in the middle of the maximum movable range in the z-axis direction, the output value of the calibration displacement sensor is (X3 + Y3)/2.

According to the invention, the magnetic levitation system is a normally-conductive magnetic levitation train levitation system, and a magnetic levitation linear motor is adopted in the normally-conductive magnetic levitation train levitation system.

The normally-guided maglev train suspension system comprises a maglev train base and a train track,

the magnetic suspension train base is provided with an inverted U-shaped holding rail, guide magnets are symmetrically arranged on the inner side of the inverted U-shaped holding rail in the x-axis direction, and suspension and traction magnets and auxiliary supporting wheels are arranged in the y-axis direction; the auxiliary supporting wheel is positioned at the top of the inner side of the U-shaped holding rail;

the train track is T-shaped and is fixedly arranged in the inverted U-shaped holding rail; the top of the train track is provided with a support track, and the support track is positioned below the auxiliary supporting wheels; a long stator core and a winding are arranged below the support rail, and the long stator core and the winding are positioned above the suspension and traction magnets; steel reaction rails are arranged on two sides of the train rail;

a displacement sensor is arranged between the adjacent suspension and traction magnets and is used for detecting the distance between the suspension and traction magnets and the long stator iron core and windings on the track,

and a displacement sensor is arranged between the adjacent guide magnets and used for detecting the distance between the guide magnets and the steel reaction rail.

According to the present invention, preferably, in the case where the magnetic levitation system is a normal-guiding magnetic levitation train levitation system, the self-calibrating the displacement sensor when the self-checking of the device is abnormal includes:

Increasing exciting currents of a suspension magnet and a traction magnet capable of generating positive y-axis acting force, enabling the magnetic suspension train to move upwards to the upper boundary of the maximum movable range in the y-axis direction, and calibrating the output value of the displacement sensor module to be X4 when the train moves upwards;

the exciting current of the suspension and traction magnet capable of generating positive Y-axis acting force is reduced to 0, the magnetic levitation train moves downwards to the lower boundary of the maximum movable range in the Y-axis direction, and the output voltage value of the displacement sensor module is calibrated to be Y4 when the train moves downwards; the positive y-axis direction is the direction opposite to the gravity direction;

thereby judging that the magnetic suspension train moves in the maximum movable range of the Y-axis direction, and calibrating the output value of the displacement sensor module to be in the interval [ X4, Y4 ]; when the train is suspended between the auxiliary supporting wheel and the magnetic suspension and traction magnets in a static suspension state of the magnetic suspension system, the output value of the corresponding displacement sensor module is calibrated to be (X4+Y4)/2, wherein the Y-axis direction is the gravity direction.

Increasing the exciting current in the left guide magnet coil capable of generating force in the x-axis direction, and adjusting the exciting current in the right guide magnet coil to 0; the magnetic suspension train moves leftwards to the left boundary of the maximum movable range in the X-axis direction, and the output value of the corresponding displacement sensor module is calibrated to be X5;

Increasing the exciting current in the right guiding magnet coil capable of generating the force in the x-axis direction, and adjusting the exciting current in the left guiding magnet coil to 0; the magnetic suspension train moves rightwards to the right boundary of the maximum movable range in the x-axis direction, and the output value of the corresponding displacement sensor module is calibrated to be Y5;

thereby judging that the magnetic suspension train moves in the maximum movable range of the X-axis direction, and calibrating the output value of the displacement sensor module to be in the interval [ X5, Y5 ]; when the train is suspended between the auxiliary supporting wheel and the magnetic suspension and traction magnet in the static suspension state of the magnetic suspension system, the output value of the corresponding displacement sensor module is calibrated to be (X5 + Y5)/2.

Self-calibration controlling means of displacement sensor based on magnetic suspension bearing includes:

the sampling module is used for acquiring the displacement signal output by the displacement sensor and the operation parameters of the magnetic suspension system;

the sensor module is used for processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

the control module is used for carrying out equipment self-inspection on the magnetic suspension system based on the processed data; when the equipment is qualified in self-inspection, the equipment is started and operated; when the self-detection of the equipment is abnormal, performing algorithm switching, and performing self-calibration on the displacement sensor;

The self-calibration module is used for running a self-calibration algorithm, namely increasing the exciting current of the electromagnet which can generate acting force in the positive/negative direction of the x axis or the y axis or the z axis in the magnetic suspension bearing, and reducing the exciting current of the electromagnet which can generate acting force in other directions in the magnetic suspension bearing to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration.

The beneficial effects of the invention are as follows:

1. the invention provides a self-calibration control method and a self-calibration control device for a displacement sensor based on a magnetic suspension bearing, wherein when the state of a magnetic suspension system is abnormal, a self-calibration module in a magnetic suspension controller is called, and before magnetic suspension equipment actually operates, the relative position of a suspension object is controlled by the magnetic suspension bearing to obtain the maximum movable range of the suspension object, so that the equipment automatically calibrates the displacement sensor in the magnetic suspension system, the equipment can stably operate for a long time with high precision, the service life of the equipment is prolonged, and the maintenance cost is reduced.

2. The self-calibration control method and the self-calibration control device for the displacement sensor based on the magnetic suspension bearing can be used in linkage with the Internet of things module, and debugging personnel can remotely call the self-calibration module to debug the magnetic suspension device, so that the device debugging efficiency is greatly improved, and the debugging cost is reduced.

3. According to the invention, sensor drift data can be recorded in the self-checking process, and the sensor drift condition can be deduced and targeted optimization can be made according to a large amount of drift data, so that the control accuracy of the sensor is further improved, and the influence caused by sensor drift is reduced.

4. The invention adopts a differential control method to correct the displacement sensor, improves the detection precision and reduces the influence caused by temperature drift.

Drawings

FIG. 1 is a schematic diagram of a self-calibrating control device for a magnetic bearing based displacement sensor;

FIG. 2 is a flow chart of a method for self-calibrating control of a displacement sensor in a single degree of freedom magnetic levitation motor;

FIG. 3 is a schematic diagram showing the radial relative positions of a radial magnetic suspension bearing and a rotor, and a displacement sensor and a rotor in rotary magnetic suspension equipment;

FIG. 4 is a schematic diagram of the axial positions of the rotor, radial magnetic bearings and corresponding displacement sensors in a rotary magnetic levitation apparatus;

FIG. 5 is a schematic diagram showing the radial contrast of the relative positions of the rotor and the radial magnetic suspension bearing when the electromagnets A and E are calibrated;

FIG. 6 is a schematic diagram of the axial positions of the rotor, radial magnetic bearings and corresponding displacement sensors when the electromagnets A and E are calibrated;

FIG. 7 is a schematic diagram showing the radial magnetic suspension bearing versus rotor, displacement sensor versus rotor radial position when the electromagnets A and E are calibrated;

FIG. 8 is a schematic diagram showing the radial contrast of the relative positions of the rotor and the radial magnetic suspension bearing when the electromagnets B and F are calibrated;

FIG. 9 is a schematic diagram of the axial positions of the rotor, radial magnetic bearings and corresponding displacement sensors when the electromagnets B and F are calibrated;

FIG. 10 is a schematic diagram showing the radial magnetic suspension bearing versus rotor, displacement sensor versus rotor radial position when the electromagnets B and F are calibrated;

FIG. 11 is a schematic diagram of axial position change of an axial magnetic bearing and a matched displacement sensor when the axial magnetic bearing is calibrated;

FIG. 12 is a flow chart of a method of self-calibration control of a magnetic levitation motor displacement sensor;

FIG. 13 is a schematic cross-sectional view of a magnetically levitated train base and train track;

Fig. 14 is a schematic cross-sectional structure of a magnetic levitation linear motor;

FIG. 15 is a schematic illustration of the relative position change of the magnetic levitation train base and the train track when the magnetic levitation train displacement sensor is calibrated along the direction of gravity;

FIG. 16 is a flow chart of a method of self-calibration control of displacement sensors in a magnetically levitated train of a normally guided type.

1. Magnetic pole pairs, 2, rotors, 3, displacement sensor probes, 4, axial magnetic suspension bearings, 5, rotor thrust disks or shaft shoulders, 6, radial magnetic suspension bearings, 7, suspension and traction magnets, 8, long stator cores and windings, 9, a steel reaction rail, 10, a guide magnet, 11, a supporting rail, 12, an auxiliary supporting wheel, 13, a magnetic levitation train base, 14, a train rail, 15, a magnetic levitation linear motor stator, 16 and a magnetic levitation linear motor rotor.

Detailed Description

The following description of the several embodiments of the present application, while clearly and fully describing the embodiments of the present invention, is provided by way of illustration, and is not intended to limit the invention to the particular embodiments disclosed, but to limit the scope of the invention to all other embodiments available to one of ordinary skill in the art without inventive faculty based on the embodiments disclosed herein.

In the present invention, unless explicitly specified and limited otherwise, the terms "coupled," "affixed," and the like are to be construed broadly, and for example, "coupled" may be either fixedly coupled, detachably coupled, or integrally formed, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical solutions of the embodiments of the present invention may be combined with each other, but it is necessary to be based on the fact that those skilled in the art can implement the technical solutions, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered as not existing, and not falling within the scope of the claimed invention.

Example 1

The embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, which comprises the following steps:

acquiring a displacement signal output by a displacement sensor and operating parameters of a magnetic suspension system;

processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

performing equipment self-checking on the magnetic suspension system based on the processed data, and starting and operating the equipment when the equipment self-checking is qualified; when the self-check of the equipment is abnormal, self-calibrating the displacement sensor by adopting a self-calibrating algorithm; the processed data refer to the displacement signals output by the processed displacement sensor and the operation parameters of the magnetic suspension system;

The self-calibration algorithm includes: increasing exciting current of an electromagnet in the magnetic suspension bearing, wherein the exciting current can generate acting force in positive/negative directions of an x axis, a y axis or a z axis, and reducing the exciting current of the electromagnet in the magnetic suspension bearing, wherein the acting force can be generated in other directions, to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration. Specifically, the magnitude of (x+y)/2 may be determined according to the magnitude of the voltage of the constant current source capable of providing a stable output, thereby determining the X and Y values.

Specifically, as shown in fig. 2, the self-calibration control method for the displacement sensor in the single-degree-of-freedom magnetic levitation motor comprises the following steps: the equipment is self-checked, and if the self-check is qualified, the equipment is started and operated;

when an abnormality exists, self-calibration is performed, specifically: the master controller pauses the starting of equipment, outputs an algorithm switching signal to the magnetic bearing control module, and starts a self-calibration algorithm;

The magnetic bearing control module outputs a control signal to enable exciting current of the electromagnet A to be maximum, exciting current of the electromagnet B is 0, and the output of the calibrated displacement sensor module is x and is fed back to the magnetic bearing control module;

the magnetic bearing control module outputs a control signal to enable exciting current of the electromagnet B to be maximum, exciting current of the electromagnet A is 0, and the output of the calibrated displacement sensor module is y and is fed back to the magnetic bearing control module;

the magnetic bearing control module is switched into an original algorithm and outputs a self-checking signal to the master controller;

and after receiving the self-checking signal, the master controller repeats the steps until the equipment is started normally.

Wherein the electromagnet A and the electromagnet B are electromagnets arranged on the same coordinate axis. Two electromagnets on the same coordinate axis jointly control one degree of freedom.

Example 2

On the basis of embodiment 1, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

the operation parameters of the magnetic suspension system comprise one or more of the following: the method comprises the following steps of (1) exciting current of a magnetic suspension bearing during static suspension of a magnetic suspension system, temperature of the magnetic suspension bearing, starting time of the magnetic suspension system and exciting current of the magnetic suspension bearing during operation of the magnetic suspension system. The temperature of the magnetic suspension bearing refers to the temperature of a coil formed by an exciting coil in the magnetic suspension bearing.

Example 3

On the basis of embodiment 1, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

when one or more of the following conditions occur, the self-detection of the device is abnormal:

when the magnetic suspension system is in static suspension, the exciting current of the magnetic suspension bearing is smaller than a first set value, and a suspension object cannot be suspended;

when the magnetic suspension system is in static suspension, the difference value between the temperature of the magnetic suspension bearing and the temperature of the magnetic suspension bearing at the last starting exceeds a second set value;

when the magnetic suspension system is in static suspension, the time interval between the starting time of the magnetic suspension system and the starting time of the last magnetic suspension system is larger than a third set value;

when the magnetic suspension system runs last time, the exciting current of the magnetic suspension bearing exceeds a fourth set value;

other magnetic levitation devices may have anomalies or malfunctions.

The first set value, the second set value, the third set value and the fourth set value are specifically determined according to the model of the equipment, the results of multiple experiments or operation and the like, and the set values corresponding to different models are different. Wherein, dynamic levitation, i.e. levitation objects can be stably levitated and the system or the device is in a moving or running state, and static levitation, i.e. levitation objects can be stably levitated but the system or the device is in a static or non-running state.

Example 4

On the basis of embodiment 1, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

the magnetic suspension system is rotary magnetic suspension equipment, wherein a magnetic suspension motor is taken as an example in the rotary magnetic suspension equipment, and a rotor 2 of the motor is taken as a suspension object;

the rotary magnetic suspension device is internally provided with a group of radial magnetic suspension bearings 6 and a group of axial magnetic suspension bearings 4, the group of radial magnetic suspension bearings 6 are sleeved outside the rotor 2, and the axial magnetic suspension bearings 4 are respectively arranged at two sides of a rotor thrust disc or shaft shoulder 5; six degrees of freedom are respectively translational motion along an x axis, a y axis and a z axis and rotation around the x axis, the y axis and the z axis under a three-dimensional space coordinate system, the radial magnetic suspension bearing 6 is used for restraining the rotor 2 to translate along the radial x axis or the y axis and rotate around the x axis or the y axis, and the axial magnetic suspension bearing 4 is used for restraining the rotor 2 to translate along the z axis; the arrangement of the set of radial magnetic bearings 6 and the set of axial magnetic bearings 4 is generally performed by those skilled in the art, and will not be described here.

The radial magnetic suspension bearing 6 comprises four electromagnets, two electromagnets are oppositely arranged on the x axis or the y axis respectively, the two electromagnets on the same coordinate axis are controlled in a differential mode, and the two electromagnets on the same coordinate axis jointly control one degree of freedom;

Specifically, the radial magnetic suspension bearing 6 has eight magnetic poles, four magnetic pole pairs 1 are provided, each magnetic pole pair 1 is used as an electromagnet, namely, the radial magnetic suspension bearing 6 comprises four electromagnets, and each electromagnet controls one direction; each radial magnetic bearing 6 controls four directions of the rotor 2.

In this embodiment, a group of axial magnetic suspension bearings 4 provided in the rotary magnetic suspension apparatus are an axial magnetic suspension bearing I and an axial magnetic suspension bearing J, respectively. The Z-axis is provided with an axial magnetic suspension bearing I and an axial magnetic suspension bearing J which are oppositely arranged, the two axial magnetic suspension bearings I and J on the same coordinate axis are controlled in a differential mode, and the axial magnetic suspension bearings I and J jointly control one degree of freedom. Four electromagnets are arranged in the axial magnetic suspension bearing I and the axial magnetic suspension bearing J, and the electromagnets are used for generating acting force in the positive/negative direction of the z axis.

The radial magnetic suspension bearing 6 and the rotor 2, and the radial relative positions of the displacement sensor and the rotor 2 are shown in fig. 3 and 4. Each magnetic pole pair 1 in the radial magnetic suspension bearing 6 is correspondingly provided with a displacement sensor, the distribution mode of the probe 3 of the displacement sensor is consistent with that of the magnetic pole pairs 1, and the differential compensation method is adopted to improve the detection precision and reduce the influence caused by temperature drift. Specifically, the displacement sensor corresponding to the magnetic pole pair A, B, C, D is A, B, C, D. The displacement sensor corresponding to the magnetic pole pair E, F, G, H is E, F, G, H.

The two displacement sensors on the x axis and the y axis are mutually differential, and a channel is corresponding to the displacement sensor module; specific: specific:

the displacement sensor A and the displacement sensor B which are arranged on the same coordinate axis are mutually differential, and a channel is corresponding to the displacement sensor module;

the displacement sensor C and the displacement sensor D which are arranged on the same coordinate axis are mutually differential, and a channel is corresponding to the displacement sensor module.

The displacement sensor E and the displacement sensor F which are arranged on the same coordinate axis are mutually differential, and a channel is corresponding to the displacement sensor module;

the displacement sensor G and the displacement sensor H which are arranged on the same coordinate axis are mutually differential, and a channel is corresponding to the displacement sensor module.

The axial magnetic suspension bearing 4 is provided with two displacement sensors, and the two displacement sensors are controlled differentially. Specifically, in the z-axis direction, two displacement sensors are disposed on the axial magnetic suspension bearing 4, the two displacement sensors correspond to a channel on the displacement sensor module, and one displacement sensor is used for testing the axial displacement of the rotor 2, and is identified in fig. 11; the other is not tested for axial displacement of the rotor 2 to compensate for temperature induced offset, not identified in fig. 11.

Example 5

On the basis of embodiment 4, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

in the case that the magnetic levitation system is a rotary magnetic levitation device, when the self-detection of the device is abnormal, self-calibrating the displacement sensor is performed, as shown in fig. 12, the self-calibrating control method of the displacement sensor based on the magnetic levitation bearing includes:

when the magnetic suspension device is started, the device performs self-checking,

if the suspension states of the magnetic suspension bearing and the sensor are not abnormal, starting and operating the equipment;

if the suspension states of the magnetic suspension bearing and the sensor are abnormal, the master controller pauses the equipment starting, and outputs an algorithm switching signal to the magnetic bearing control module, namely the starting is a self-calibration algorithm;

specifically, the self-calibration mode of the displacement sensor matched with the radial magnetic suspension bearing 6 is as follows:

when the magnetic suspension device is started, the device performs self-checking, and if the suspension states of the magnetic suspension bearing and the sensor are abnormal, the master controller outputs signals to the magnetic suspension control module, and the magnetic bearing control module switches the control algorithm.

As shown in fig. 5, the magnetic levitation controller outputs a control signal to synchronously increase the exciting currents of the magnetic pole pair a and the magnetic pole pair E, simultaneously reduces the exciting currents of the other magnetic pole pair 1 to 0, and simultaneously makes the electromagnetic attraction force of the magnetic pole pair a and the magnetic pole pair E upward to move the rotor 2 upward until the upper boundary of the maximum movable range in the positive direction of the y-axis. As shown in fig. 6 and 7. At this time, when the suspended object approaches the displacement sensor probes a and E and cannot continue to move, digital potentiometers corresponding to the displacement sensor A, B and the displacement sensor E, F on the modules are adjusted, so that the output voltage values of the displacement sensor modules on the AB path and the EF path are X1.

As shown in fig. 8, the magnetic levitation controller outputs a control signal to synchronously increase the exciting currents of the magnetic pole pair B and the magnetic pole pair F, and simultaneously reduces the exciting currents of the other magnetic pole pair 1 to 0, and the electromagnetic attraction force of the magnetic pole pair B and the magnetic pole pair F simultaneously moves downward, so that the rotor 2 moves downward until the lower boundary of the maximum movable range in the negative direction of the y axis. As shown in fig. 9 and 10. At this time, when the suspended object approaches the probes B and F of the displacement sensor and cannot continue to move, digital potentiometers corresponding to the displacement sensor A, B and the displacement sensor E, F on the modules are adjusted, so that the output voltage values of the displacement sensor modules on the AB path and the EF path are Y1.

Thereby, it is determined that the rotor 2 moves within the maximum movable range in the Y-axis direction, and the output voltage value of the displacement sensor is within the section [ X1, Y1 ]. When the magnetic levitation system is in static levitation, the rotor 2 is levitated between the magnetic pole pair A, E and the magnetic pole pair B, F, and the displacement sensor outputs a voltage value of (x1+y1)/2. Where displacement sensor A, B is located in the y-axis direction and displacement sensor E, F is located in the y-axis direction.

In the same manner, self-calibration of the displacement sensor C, D and the displacement sensor G, H in the X-axis direction is performed, and the maximum movable range of the rotor 2 in the X-axis direction is obtained, and the output voltage value of the displacement sensor is within the interval [ X2, Y2 ]. When the magnetic levitation system is in static levitation, the rotor 2 is levitated between the magnetic pole pair C, G and the magnetic pole pair D, H, and the displacement sensor outputs a voltage value of (x2+y2)/2.

The self-calibration mode of the axial magnetic suspension bearing 4 matched with the displacement sensor is as follows:

as shown in fig. 11, the axial magnetic bearing I and the axial magnetic bearing J are sleeved on both sides of the rotor thrust disc or shaft shoulder 5, and fig. 11 only illustrates the rotor 2 and one electromagnet of the axial magnetic bearings I and J. The magnetic suspension controller outputs a control signal to increase the exciting current of the axial magnetic suspension bearing J, meanwhile, the exciting current of the other axial magnetic suspension shaft I is reduced to 0, the electromagnetic attraction force of the axial magnetic suspension bearing J is rightward, the rotor 2 is enabled to move rightward until the right boundary of the maximum movable range in the positive direction of the z-axis, at the moment, a suspension object is close to the displacement sensor probe 3 and cannot move continuously, and then digital potentiometers corresponding to the two displacement sensors on the module are adjusted, so that the output voltage value of the displacement sensor module on the IJ path is X3.

And increasing the exciting current of the axial magnetic suspension bearing I, reducing the exciting current of the axial magnetic suspension bearing J to 0, and enabling the electromagnetic attraction force of the axial magnetic suspension bearing I to left so as to enable the rotor 2 to move left until the left boundary of the maximum movable range in the negative direction of the z axis, wherein at the moment, a suspended object is close to the displacement sensor probe 3 and cannot move continuously, and then adjusting the digital potentiometers corresponding to the two displacement sensors on the module so as to enable the output voltage value of the displacement sensor module on the IJ path to be Y3.

Thereby, it is determined that the rotor 2 moves within the maximum movable range in the axial direction, and the output value of the displacement sensor module is within the interval [ X3, Y3 ]. When the magnetic suspension system is in static suspension and the rotor 2 is in the middle of the maximum movable range in the z-axis direction, digital potentiometers corresponding to the two displacement sensors on the module are adjusted, so that the output voltage value of the displacement sensor module on the IJ path is (X3 + Y3)/2. When the rotor thrust disk or shoulder 5 is suspended between the axial magnetic bearings I and J, the rotor 2 is positioned at the intermediate position of the maximum movable range in the z-axis direction.

Example 6

On the basis of embodiment 1, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

the magnetic suspension system is a normally-conductive magnetic suspension train suspension system, and a magnetic suspension linear motor is adopted in the normally-conductive magnetic suspension train suspension system, and as shown in fig. 13 and 14, the magnetic suspension linear motor comprises a magnetic suspension linear motor stator 15 and a magnetic suspension linear motor rotor 16.

As shown in fig. 13, the constant-velocity magnetic levitation system includes a magnetic levitation train base 13 and a train track 14,

the magnetic suspension train base 13 is provided with an inverted U-shaped holding rail, guide magnets 10 are symmetrically arranged on the inner side of the inverted U-shaped holding rail in the x-axis direction, and suspension and traction magnets 7 and auxiliary supporting wheels 12 are arranged in the y-axis direction; the auxiliary supporting wheel 12 is positioned at the top of the inner side of the U-shaped holding rail;

The train track 14 is T-shaped, and the train track 14 is fixedly arranged in the inverted U-shaped holding rail; the top of the train track 14 is provided with a support track, which is located below the auxiliary support wheels 12; a long stator core and a winding 8 are arranged below the support rail, and the long stator core and the winding 8 are positioned above the suspension and traction magnet 7; the train track 14 is provided with steel reaction rails 9 on both sides.

Exciting current is introduced into the levitation and traction magnet 7, and electromagnetic attraction is generated between the levitation and traction magnet 7 on the magnetic levitation train base 13 and the long stator iron core and winding 8 on the train track 14 to counteract the gravity of the magnetic levitation train.

As shown in fig. 14, a displacement sensor is arranged between the adjacent levitation and traction magnets 7, and is used for detecting the distance between the levitation and traction magnets 7 and the long stator core and the winding 8 on the track;

a displacement sensor is arranged between the adjacent guide magnets 10 for detecting the distance between the guide magnets 10 and the steel reaction rail 9.

Specifically, two displacement sensors are arranged between adjacent levitation and traction magnets 7, and one displacement sensor is used for detecting the distance between the levitation and traction magnets 7 and the long stator core and windings 8 on the track; the other displacement sensor adopts a shell to encapsulate the probe for compensating the offset caused by temperature, the two displacement sensors are mutually differential, and a channel corresponds to the displacement sensor module, so that the differential compensation of the displacement sensor is realized.

Similarly, two displacement sensors are provided between adjacent guide magnets 10.

The total controller adjusts the exciting current in the electromagnet coil through the magnetic bearing control module and the power amplification module according to the voltage signal of the actual distance and the standard deviation value so as to keep a levitation air gap (about 10mm, for example).

The guide magnet 10 on the magnetic suspension train generates lateral suction force to the steel reaction rail 9 on the side surface of the train track 14, the displacement sensor probe 3 is also arranged between coils of the guide magnet 10, and when the train runs, the displacement sensor probe 3 detects accurate offset and converts the accurate offset into voltage signals through the sampling module and the displacement sensor module, and the exciting current is regulated through the magnetic bearing control module and the power amplification module, so that the track is always positioned at the central position of the train.

To ensure control accuracy, each set of poles is equipped with a dedicated displacement sensor system.

Example 7

On the basis of embodiment 6, the present embodiment provides a self-calibration control method of a displacement sensor based on a magnetic suspension bearing, specifically:

under the condition that the magnetic suspension system is a normally-conductive magnetic suspension train suspension system, when the self-checking of the equipment is abnormal, the displacement sensor is self-calibrated.

The self-calibration process of the levitation system of the normally-guided magnetic levitation train as shown in fig. 16 includes:

before the train is started, self-checking is performed first;

if the state of the suspension system of the magnetic suspension train is abnormal, the master controller outputs signals to the magnetic suspension control module, and the magnetic bearing control module performs a switching algorithm and adopts a self-correction algorithm;

self-calibration of the magnetically levitated matched displacement sensor along the y-axis direction is specifically as follows:

as shown in fig. 15, a magnetic levitation controller outputs a control signal to increase exciting current in a coil of a levitation and traction magnet 7 capable of generating force in the y-axis direction, electromagnetic attraction between the levitation and traction magnet 7 and a long stator core and winding 8 counteracts gravity of a magnetic levitation train, the magnetic levitation train moves upwards to enable the levitation and traction magnet 7 to be in contact with the long stator core and winding 8, a corresponding digital potentiometer on a channel where each displacement sensor probe 3 is located is adjusted, and an output voltage value of a displacement sensor module is X4 when the train moves upwards;

then, exciting current in coils of the suspension and traction magnets 7 is reduced to 0, the train moves downwards under the influence of gravity, auxiliary supporting wheels on the train are contacted with the supporting rail 11, and corresponding digital potentiometers on a channel where each displacement sensor probe 3 is positioned are adjusted, so that an output voltage value of the displacement sensor module is Y4 when the train moves downwards;

Thereby determining that the magnetic levitation train moves in the maximum movable range of the Y-axis direction, and the output value of the sensor is in the interval [ X4, Y4 ]. The train is suspended in the middle of the track, and the output voltage value of the displacement sensor is (X4+Y4)/2. Wherein the negative y-axis direction is the gravitational direction.

Similarly, the self calibration of the magnetic suspension matched displacement sensor in the x-axis direction is specifically as follows:

outputting a control signal by the magnetic suspension controller, increasing the exciting current in the coil of the left guide magnet 10 capable of generating the force in the x-axis direction, and adjusting the exciting current in the coil of the right guide magnet 10 to 0; the left guide magnet 10 is contacted with the steel reaction rail 9, and the corresponding digital potentiometer on the channel where each displacement sensor probe 3 is positioned is adjusted, so that the output voltage value of the displacement sensor module is X5 when the train moves upwards.

Then, the exciting current in the coil of the right guide magnet 10 capable of generating the force in the x-axis direction is increased, and the exciting current in the coil of the left guide magnet 10 is adjusted to 0; the right guide magnet 10 is contacted with the steel reaction rail 9, and the corresponding digital potentiometer on the channel where each displacement sensor probe 3 is positioned is adjusted, so that the output voltage value of the displacement sensor module is Y5 when the train moves right.

Thereby determining that the magnetic levitation train moves within the maximum movable range in the X-axis direction, and the output value of the sensor is within the interval [ X5, Y5 ]. When the magnetic suspension system is in static suspension, the magnetic suspension train is suspended in the middle of the track, and the displacement sensor outputs a displacement signal of (X5 + Y5)/2 at the moment.

Example 8

The embodiment provides a self-calibration control device of a displacement sensor based on a magnetic suspension bearing, which comprises:

the sampling module is used for acquiring the displacement signal output by the displacement sensor and the operation parameters of the magnetic suspension system;

in this embodiment, as shown in fig. 1, the sampling module includes a displacement sensor and a temperature sensor, and in this embodiment, the temperature sensor is a temperature sensor with a model PT 100.

The sensor module is used for processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

in this embodiment, the sensor module includes a temperature sensor module and a displacement sensor module, and data processed by the temperature sensor module and the displacement sensor module is transmitted to the overall controller.

The control module is used for carrying out equipment self-inspection on the magnetic suspension system based on the processed data; when the equipment is qualified in self-inspection, the equipment is started and operated; when the self-detection of the equipment is abnormal, performing algorithm switching, and performing self-calibration on the displacement sensor;

The self-calibration module is used for running a self-calibration algorithm, namely increasing the exciting current of the electromagnet which can generate acting force in the positive/negative direction of the x axis or the y axis or the z axis in the magnetic suspension bearing, and reducing the exciting current of the electromagnet which can generate acting force in other directions in the magnetic suspension bearing to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration.

In this embodiment, the control module includes a master controller and a magnetic bearing control module, when the equipment is qualified in self-inspection, the master controller outputs an equipment operation signal to the magnetic bearing control module, and the magnetic bearing control module outputs a signal to amplify and control the exciting current of the radial magnetic bearing 6 or the axial magnetic bearing 4 through a power amplifier;

when the self-checking of the equipment is abnormal, the master controller pauses the equipment to start, outputs an algorithm switching signal to the magnetic bearing control module, and starts the self-calibration module to perform self-calibration. After the self calibration is completed, the magnetic bearing control module is switched back to the original algorithm, and a self-checking signal is output to the master controller, the master controller performs the self-checking of the equipment again, and the steps are repeated until the self-checking is qualified.

The foregoing is a description of several embodiments of the present invention, and is not intended to limit the invention to the particular embodiments disclosed, but is not intended to limit the invention to the particular embodiments disclosed, as the invention may be modified or varied in several ways within the scope of the invention.

Claims (8)

1. The self-calibration control method of the displacement sensor based on the magnetic suspension bearing is characterized by comprising the following steps of:

acquiring a displacement signal output by a displacement sensor and operating parameters of a magnetic suspension system;

processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

performing equipment self-checking on the magnetic suspension system based on the processed data, and starting and operating the equipment when the equipment self-checking is qualified; when the self-check of the equipment is abnormal, self-calibrating the displacement sensor by adopting a self-calibrating algorithm;

The self-calibration algorithm includes: increasing exciting current of an electromagnet in the magnetic suspension bearing, wherein the exciting current can generate acting force in positive/negative directions of an x axis, a y axis or a z axis, and reducing the exciting current of the electromagnet in the magnetic suspension bearing, wherein the acting force can be generated in other directions, to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration.

2. The self-calibration control method of a magnetic bearing based displacement sensor according to claim 1, wherein the operating parameters of the magnetic levitation system include one or more of the following: the method comprises the following steps of (1) exciting current of a magnetic suspension bearing during static suspension of a magnetic suspension system, temperature of the magnetic suspension bearing, starting time of the magnetic suspension system and exciting current of the magnetic suspension bearing during operation of the magnetic suspension system.

3. The self-calibration control method of a magnetic bearing based displacement sensor according to claim 1, wherein the self-checking of the device for the presence of anomalies comprises:

When the magnetic suspension system is in static suspension, the exciting current of the magnetic suspension bearing is smaller than a first set value;

when the magnetic suspension system is in static suspension, the difference value between the temperature of the magnetic suspension bearing and the temperature of the magnetic suspension bearing at the last starting exceeds a second set value;

when the magnetic suspension system is in static suspension, the time interval between the starting time of the magnetic suspension system and the starting time of the last magnetic suspension system is larger than a third set value;

and when the magnetic suspension system runs last time, the exciting current of the magnetic suspension bearing exceeds a fourth set value.

4. The self-calibration control method of a displacement sensor based on a magnetic bearing according to claim 1, wherein the magnetic suspension system is a rotary magnetic suspension device, and a rotor of a motor is used as a suspension object;

the rotary magnetic suspension device is provided with a group of radial magnetic suspension bearings and a group of axial magnetic suspension bearings, the group of radial magnetic suspension bearings are sleeved outside the rotor, and the group of axial magnetic suspension bearings are arranged on two sides of the thrust disc or the shaft shoulder of the rotor;

the radial magnetic suspension bearing comprises four electromagnets, wherein two electromagnets are oppositely arranged on an x axis or a y axis respectively, and the two electromagnets on the same coordinate axis are controlled in a differential mode, and the two electromagnets on the same coordinate axis jointly control one degree of freedom;

Two axial magnetic suspension bearings are oppositely arranged on the z-axis, the two axial magnetic suspension bearings on the same coordinate axis are controlled in a differential mode, and the two axial magnetic suspension bearings jointly control one degree of freedom;

each electromagnet in the radial magnetic suspension bearing is correspondingly provided with a displacement sensor, the distribution mode of a probe of the displacement sensor is consistent with that of the electromagnet, and the two displacement sensors on the same coordinate axis are controlled in a differential mode;

the axial magnetic suspension bearing is provided with two displacement sensors, and the two displacement sensors are controlled in a differential mode.

5. The self-calibration control method of a displacement sensor based on a magnetic bearing according to claim 4, wherein, in the case that the magnetic suspension system is a rotary magnetic suspension device, when the self-check of the device is abnormal, the self-calibration is performed on the displacement sensor, comprising:

the self-calibration mode of the radial magnetic suspension bearing matched displacement sensor is as follows:

synchronously increasing exciting currents of electromagnets capable of generating positive/negative direction acting forces of a Y axis in a group of radial magnetic suspension bearings, reducing the exciting currents of electromagnets capable of generating other direction acting forces in the radial magnetic suspension bearings to 0, obtaining the maximum movable range of a rotor in the positive/negative direction of the Y axis, and calibrating the output value of a corresponding displacement sensor module to be X1/Y1;

Thereby determining that the rotor moves within the maximum movable range in the positive/negative direction of the Y-axis, and the output value of the displacement sensor module is within the interval [ X1, Y1 ]; when the rotor is suspended in the middle of the maximum movable range in the Y-axis direction, the output value of the corresponding displacement sensor module is (X1 +Y1)/2;

synchronously increasing exciting currents of electromagnets capable of generating positive/negative direction acting forces of an X axis in a group of radial magnetic suspension bearings, reducing the exciting currents of electromagnets capable of generating other direction acting forces in the radial magnetic suspension bearings to 0, obtaining the maximum movable range of a rotor in the positive/negative direction of the X axis, and calibrating the output value of a corresponding displacement sensor module to be X2/Y2;

thereby judging that the rotor moves in the maximum movable range in the positive/negative direction of the X-axis, and the output value of the corresponding displacement sensor module is in the interval [ X2, Y2 ]; in a static suspension state of the magnetic suspension system, when the rotor is suspended in the middle of the maximum movable range in the X-axis direction, the output value of the corresponding displacement sensor is (X < 2+Y < 2 >)/2;

the self-calibration mode of the axial magnetic suspension bearing matched displacement sensor is as follows:

increasing exciting current of an axial magnetic suspension bearing capable of generating positive/negative direction acting force of a z axis, reducing exciting current of the other axial magnetic suspension bearing to 0 at the same time, obtaining the maximum movable range of a rotor in the positive/negative direction of the z axis, and calibrating the output value of a displacement sensor module in the positive/negative direction of the z axis to be X3/Y3;

Thereby determining that the rotor moves within the maximum movable range in the positive/negative direction of the z-axis, and the output value of the displacement sensor module is within the interval [ X3, Y3 ]; in the static suspension state of the magnetic suspension system, when the rotor is in the middle of the maximum movable range in the z-axis direction, the output value of the calibration displacement sensor is (X3 + Y3)/2.

6. The self-calibration control method of a magnetic bearing based displacement sensor according to claim 1, wherein the magnetic levitation system is a normally-conductive magnetic levitation train levitation system,

the normally-guided maglev train suspension system comprises a maglev train base and a train track,

the magnetic suspension train base is provided with an inverted U-shaped holding rail, guide magnets are symmetrically arranged on the inner side of the inverted U-shaped holding rail in the x-axis direction, and suspension and traction magnets and auxiliary supporting wheels are arranged in the y-axis direction; the auxiliary supporting wheel is positioned at the top of the inner side of the U-shaped holding rail;

the train track is T-shaped and is fixedly arranged in the inverted U-shaped holding rail; the top of the train track is provided with a support track, and the support track is positioned below the auxiliary supporting wheels; a long stator core and a winding are arranged below the support rail, and the long stator core and the winding are positioned above the suspension and traction magnets; steel reaction rails are arranged on two sides of the train rail;

A displacement sensor is arranged between the adjacent suspension and traction magnets and is used for detecting the distance between the suspension and traction magnets and the long stator iron core and windings on the track,

and a displacement sensor is arranged between the adjacent guide magnets and used for detecting the distance between the guide magnets and the steel reaction rail.

7. The self-calibration control method of a displacement sensor based on a magnetic bearing according to claim 6, wherein, in the case that the magnetic levitation system is a normal-conduction type magnetic levitation train levitation system, when the self-check of the equipment is abnormal, the self-calibration of the displacement sensor is performed, comprising:

increasing exciting currents of a suspension magnet and a traction magnet capable of generating positive y-axis acting force, enabling the magnetic suspension train to move upwards to the upper boundary of the maximum movable range in the y-axis direction, and calibrating the output value of the displacement sensor module to be X4 when the train moves upwards;

the exciting current of the suspension and traction magnet capable of generating positive Y-axis acting force is reduced to 0, the magnetic levitation train moves downwards to the lower boundary of the maximum movable range in the Y-axis direction, and the output voltage value of the displacement sensor module is calibrated to be Y4 when the train moves downwards; the positive y-axis direction is the direction opposite to the gravity direction;

Thereby judging that the magnetic suspension train moves in the maximum movable range of the Y-axis direction, and calibrating the output value of the displacement sensor module to be in the interval [ X4, Y4 ]; when the train is suspended between the auxiliary supporting wheel and the magnetic suspension and traction magnet in a static suspension state of the magnetic suspension system, calibrating the output value of the corresponding displacement sensor module to be (X4 + Y4)/2, wherein the Y-axis direction is the gravity direction;

increasing the exciting current in the left guide magnet coil capable of generating force in the x-axis direction, and adjusting the exciting current in the right guide magnet coil to 0; the magnetic suspension train moves leftwards to the left boundary of the maximum movable range in the X-axis direction, and the output value of the corresponding displacement sensor module is calibrated to be X5;

increasing the exciting current in the right guiding magnet coil capable of generating the force in the x-axis direction, and adjusting the exciting current in the left guiding magnet coil to 0; the magnetic suspension train moves rightwards to the right boundary of the maximum movable range in the x-axis direction, and the output value of the corresponding displacement sensor module is calibrated to be Y5;

thereby judging that the magnetic suspension train moves in the maximum movable range of the X-axis direction, and calibrating the output value of the displacement sensor module to be in the interval [ X5, Y5 ]; when the train is suspended between the auxiliary supporting wheel and the magnetic suspension and traction magnet in the static suspension state of the magnetic suspension system, the output value of the corresponding displacement sensor module is calibrated to be (X5 + Y5)/2.

8. The self-calibration control device of the displacement sensor based on the magnetic suspension bearing is characterized by comprising:

the sampling module is used for acquiring the displacement signal output by the displacement sensor and the operation parameters of the magnetic suspension system;

the sensor module is used for processing the acquired displacement signals output by the displacement sensor and the operation parameters of the magnetic suspension system;

the control module is used for carrying out equipment self-inspection on the magnetic suspension system based on the processed data; when the equipment is qualified in self-inspection, the equipment is started and operated; when the self-detection of the equipment is abnormal, performing algorithm switching, and performing self-calibration on the displacement sensor;

the self-calibration module is used for running a self-calibration algorithm, namely increasing the exciting current of the electromagnet which can generate acting force in the positive/negative direction of the x axis or the y axis or the z axis in the magnetic suspension bearing, and reducing the exciting current of the electromagnet which can generate acting force in other directions in the magnetic suspension bearing to 0; calibrating the output value of the displacement sensor module in a section [ X, Y ] within the maximum movable range of the suspension object in the direction of the X-axis, the Y-axis or the z-axis; in a static suspension state of the magnetic suspension system, when a suspension object is suspended in the middle of the maximum movable range on the X axis or the Y axis or the z axis, calibrating a displacement signal value output by the displacement sensor to be (X+Y)/2; thereby completing the displacement sensor self-calibration.

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