CN214670177U

CN214670177U - Signal detection device and magnetic suspension system

Info

Publication number: CN214670177U
Application number: CN202121087077.9U
Authority: CN
Inventors: 郭伟林; 郑安琪; 孙建东; 林润方
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2021-11-09
Anticipated expiration: 2031-05-20

Abstract

The utility model discloses a signal detection device and magnetic suspension system, the device includes: each sampling module in the N sampling modules is configured to sample one path of signal in the N paths of signals to be sampled to obtain a sampling signal of the path of signal; the mixing unit is configured to mix the sampling signals of the N paths of signals to obtain a path of mixed sampling signal; the control chip is configured to receive one path of mixed sampling signals through one path of sampling channels of the control chip, and process the one path of mixed sampling signals so as to extract sampling signals of N paths of signals from the one path of mixed sampling signals. According to the scheme, the multichannel sampling signals are subjected to mixed sampling and then are separated by utilizing one internal sampling channel of the control chip, and the acquisition of each parameter in the running state of the magnetic suspension system can be realized under the condition that the internal sampling channel of the control chip is limited.

Description

Signal detection device and magnetic suspension system

Technical Field

The utility model belongs to the technical field of the magnetic suspension, concretely relates to displacement detection device, magnetic suspension system and displacement detection method thereof especially relate to a magnetic suspension system's displacement detection device, have this displacement detection device's magnetic suspension system and this magnetic suspension system's displacement detection method.

Background

Magnetic levitation (EML or EMS) is a technique for levitating an object by using magnetic force to overcome gravity. The system of magnetic suspension technique, namely magnetic suspension system, is made up of rotor, sensor, controller and actuator 4, wherein the actuator includes two parts of electromagnet and power amplifier. Assuming that the rotor is displaced from its reference position by a downward disturbance at the reference position, the sensor detects the displacement of the rotor from the reference position, the microprocessor as a controller converts the detected displacement into a control signal, which is then converted by a power amplifier into a control current, which generates a magnetic force in the actuator magnet, thereby driving the rotor back to its original equilibrium position. Therefore, the rotor can be always in a stable equilibrium state whether the rotor is disturbed downward or upward.

For knowing the running state of the magnetic suspension system in real time to improve the running stability and reliability of the system, sampling and feedback of various signals are required, and specific signals are as follows: displacement, velocity, current, electromagnetic force, magnetic flux, etc.

Taking the active magnetic suspension bearing system as an example, at least 5 paths of displacement sampling and 10 paths of current sampling are required, and data such as module temperature, electromagnetic force and the like are required to be fed back in real time. The control chip used for sampling, such as a DSP (digital signal processing) processor, an ARM (reduced instruction set computer microprocessor with low power consumption cost), and the like, has limited internal sampling channels, and cannot meet the requirement of sampling all the data, so that only part of the data can be sampled.

The above is only for the purpose of assisting understanding of the technical solutions of the present invention, and does not represent an admission that the above is the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a signal detection device and magnetic suspension system, need the sampling channel of the same kind of exclusive use with every way sampling signal of solving the magnetic suspension system, and control chip's inside sampling channel is limited, can't satisfy the problem of the collection of each parameter in the running state of magnetic suspension system, reach an inside sampling channel through utilizing control chip, reseparation after mixing the sampling is carried out to multichannel sampling signal, can be under the limited circumstances of control chip's inside sampling channel, realize the effect of the collection of each parameter in the running state of magnetic suspension system.

The utility model provides a signal detection device, include: the device comprises a sampling unit, a mixing unit and a control chip; the sampling unit includes: the number of the sampling modules is N, the N sampling modules are arranged in parallel, and N is a positive integer; each of the N sampling modules is configured to sample one of the N signals to be sampled to obtain a sampled signal of the one signal; the mixing unit is configured to mix the sampling signals of the N channels of signals to obtain a channel of mixed sampling signal; the control chip is configured to receive one path of the mixed sampling signal through one path of the sampling channel of the control chip, process one path of the mixed sampling signal, and extract N paths of signals from one path of the mixed sampling signal.

In some embodiments, the sampling signal comprises: shifting the sampling signal; each of the sampling modules includes: two paths of displacement sampling modules and one path of difference module; each sampling module samples one path of signal in N paths of signals to be sampled to obtain a sampling signal of the one path of signal, and the sampling module comprises: the two paths of displacement sampling modules are configured to collect displacement signals at two positions of the equipment to be controlled under one degree of freedom to obtain two paths of displacement signals; and the differential module is configured to perform differential processing on the two paths of displacement signals to obtain a path of displacement sampling signal.

In some embodiments, the excitation sources of the N sampling modules are different in the N degrees of freedom; under each degree of freedom, the excitation sources of the two paths of displacement sampling modules are the same; each of the displacement sampling modules includes: LC resonant network model.

In some embodiments, the mixing unit comprises: an addition module; the mixing unit is used for mixing the sampling signals of the N paths of signals to obtain a path of mixed sampling signal, and comprises: the adding module is configured to add the sampling signals of the N paths of signals to obtain a path of mixed sampling signal.

In some embodiments, the processing, by the control chip, one path of the mixed sampling signal includes: performing Fourier transform on one path of the mixed sampling signal to obtain a first transform signal; and carrying out inverse Fourier transform on the first transform signal according to the frequency of the excitation source of the sampling signals of the N paths of signals so as to extract the sampling signals of the N paths of signals in the mixed sampling signals.

In some embodiments, further comprising: an amplitude modulation unit; the amplitude modulation unit is configured to perform amplitude modulation processing on one path of the mixed sampling signal output by the mixing unit, so that the amplitude of the one path of the mixed sampling signal output by the mixing unit is conditioned to be within a set amplitude range, and then the one path of the mixed sampling signal is output to one path of the sampling channel in the control chip.

In some embodiments, further comprising: the control chip is also configured to control the device to be controlled according to the sampling signals of the N paths of signals extracted from the one path of mixed sampling signal.

With the above device phase-match, the utility model discloses another aspect provides a magnetic levitation system, include: the signal detection device described above.

Therefore, the scheme of the utility model, through sampling to the multichannel sampling signal of magnetic suspension system through an ADC passageway, separate this multichannel sampling signal according to this through Fourier transform and inverse transform in the control chip inside, carry out corresponding control to multichannel sampling signal again; therefore, the multi-channel sampling signals are mixed and sampled and then separated by utilizing one internal sampling channel of the control chip, the acquisition of each parameter in the running state of the magnetic suspension system can be realized under the condition that the internal sampling channel of the control chip is limited, and the sampling channel is saved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a magnetic bearing dual-ring control system;

FIG. 2 is a schematic structural diagram of an embodiment of a single degree of freedom magnetic bearing control system;

FIG. 3 is a schematic structural diagram of an embodiment of a displacement sampling apparatus in a related embodiment;

FIG. 4 is a schematic diagram of an embodiment of an operational amplifier circuit according to the related art;

fig. 5 is a schematic structural diagram of an embodiment of the signal detection apparatus of the present invention;

fig. 6 is a schematic structural diagram of an embodiment of the displacement sampling apparatus of the present invention;

fig. 7 is a schematic structural diagram of an embodiment of an amplitude modulation circuit according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a control logic of an embodiment of a magnetic levitation system of the present invention, specifically a schematic diagram of a control logic of an FX example;

fig. 9 is a schematic flow chart of an embodiment of a signal detection method according to the present invention;

fig. 10 is a schematic flow chart illustrating an embodiment of sampling one of the N signals to be sampled according to the method of the present invention;

fig. 11 is a schematic flow chart of an embodiment of processing one path of the mixed sampling signal in the method of the present invention.

Detailed Description

To make the purpose, technical solution and advantages of the present invention clearer, the following will combine the embodiments of the present invention and the corresponding drawings to clearly and completely describe the technical solution of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

FIG. 1 is a schematic structural diagram of an embodiment of a magnetic bearing double-ring control system. As shown in fig. 1, the magnetic suspension bearing dual-ring control system comprises: the device comprises a first comparator, a position controller, a second comparator, a current controller, a power amplifier, an electromagnet, a current feedback module and a position feedback module. The non-inverting input end of the first comparator inputs a reference value. And the inverted input end of the first comparator inputs the position parameter fed back by the position feedback module. The output end of the first comparator is output to the non-inverting input end of the second comparator after passing through the position controller, and the inverting input end of the second comparator inputs the current parameter fed back by the current feedback module. The output end of the second comparator is output to the electromagnet after passing through the current controller and the power amplifier and is also fed back to the input end of the current feedback module. And the electromagnet is also fed back to the input end of the position feedback module. As shown in fig. 1, the magnetic suspension dual-loop control system, in which the position loop is an outer loop, realizes real-time control of the rotor space state by feeding back the current rotor displacement through the displacement sensor; the current loop is an inner loop, and the electromagnetic force of the bearing is controlled by controlling the current of the magnetic bearing coil.

Fig. 2 is a schematic structural diagram of an embodiment of a single-degree-of-freedom magnetic suspension bearing control system. The single degree of freedom magnetic levitation control system shown in fig. 2 is explained by taking the radial direction X (FX) as an example. In order to eliminate noise interference, each displacement sensor has 2 probes for displacement signal detection, displacement signals FX1_ OUTPUT and FX2_ OUTPUT are obtained respectively, a differential signal P _ OUTPUT is obtained through a differential circuit, namely, an FX direction final displacement signal is obtained, and then the FX direction final displacement signal is sampled through an ADC channel and enters a control chip.

The eddy current displacement sensor uses high-frequency alternating current as an excitation source of a probe coil, when the position of a rotor to be detected and the position of the probe coil change, the inductance of the coil changes along with the position, the change is converted into voltage through a circuit, and the voltage represents the corresponding displacement of the rotor. As can be seen from fig. 2, each degree of freedom requires 2 probes for displacement signal detection, and 5 displacement signals require 10 probes for displacement signal detection, and finally 5 paths of displacement signals are output to the control chip.

Fig. 3 is a schematic structural diagram of an embodiment of a displacement sampling apparatus in the related art. In the displacement sampling device shown in fig. 3, 10 displacement probes use an excitation source (obtained by controlling a chip PWM pin), and the excitation frequency is the same as the resonance frequency of the probes. Specifically, 5 paths of displacement signals pass through 5 paths of filtering and amplifying circuits and are sampled through an ADC (analog to digital converter) sampling channel, and the 5 paths of displacement sensors all use the same excitation source.

Taking the FX-direction displacement signal as an example for explanation, 2 probes respectively collect displacement signals FX1_ OUTPUT and FX2_ OUTPUT, OUTPUT the displacement signal FX _ OUTPUT through a differential circuit, perform operational amplification and filtering on the signals, and enter the control chip through a sampling channel ADCINT 1. In addition, 4 displacement signals have the same principle, namely, the original scheme needs 5 paths of operational amplification circuits, 5 paths of filter circuits and 5 paths of ADC sampling channels.

Fig. 4 is a schematic structural diagram of an embodiment of an operational amplifier circuit in a related art. As shown in fig. 4, the operational amplifier circuit includes: comparator, resistance R ', electric capacity C and electric capacity C'. The shift signal FX1_ OUTPUT is input to the inverting input of the comparator. The shift signal FX2_ OUTPUT is input to the non-inverting input terminal of the comparator. The inverting input end of the comparator is connected to the output end of the comparator after passing through the resistor R. The non-inverting input end of the comparator is grounded GND after passing through the resistor R'. The capacitor C is connected with the resistor R in parallel, and the capacitor C 'is connected with the resistor R' in parallel. The OUTPUT terminals of the comparators OUTPUT the shift signals FX1_ OUTPUT and FX2_ OUTPUT after being differentiated, and then OUTPUT the shift signals FX _ OUTPUT. The positive power end of the comparator is connected with the direct current power supply + Vcc. And the negative power end of the comparator is connected with a direct current power supply-Vcc.

Fig. 4 shows the operational amplifier circuit of the above-mentioned solution shown in fig. 3, which mainly performs amplification and filtering functions on the displacement signal.

The method aims at the problem that the internal sampling channel of the control chip is limited and the acquisition of each parameter in the running state of the magnetic suspension system cannot be met. In the related scheme, an external ADC sampling chip or a control chip with more external sampling channels (such as using a DSP to perform operation control and using an external control chip to perform signal sampling) is adopted, but the external scheme introduces inter-chip communication delay in a control loop, and the delay is often not negligible relative to control time, so that the control speed and the control effect are influenced.

Specifically, the external sampling chip or other control chips for sampling function are used, which is equivalent to that a sampling delay is added in the control loop, that is, the real-time sampling signal is delayed for a period of time and then sent to the control chip for closed-loop control, and when the control signal output by the control chip is outdated, the current running state of the magnetic suspension may have changed, thereby affecting the control effect.

According to the utility model discloses an embodiment provides a signal detection device. Referring to fig. 1, a schematic structural diagram of an embodiment of the apparatus of the present invention is shown. The signal detection device may include: sampling unit, mixing unit and control chip. The sampling unit includes: the sampling module, the quantity of sampling module is N, and N sampling module sets up in parallel, and N is the positive integer. The N sampling modules are respectively connected to the mixing unit and are connected to 1-path sampling channel in the control chip, such as an ADC (analog to digital converter) sampling channel, after passing through the mixing unit.

Each of the N sampling modules is configured to sample one of the N signals to be sampled, so as to obtain a sampled signal of the one signal.

And the mixing unit is configured to mix the sampling signals of the N paths of signals to obtain a path of mixed sampling signal.

The control chip is configured to receive one path of the mixed sampling signal through one path of the sampling channel of the control chip, process one path of the mixed sampling signal, and extract N paths of signals from one path of the mixed sampling signal.

Thus, the utility model discloses a scheme provides a displacement detection device of magnetic suspension system, through an inside sampling passageway that utilizes control chip, carries out reseparation after mixing the sampling to multichannel sampled signal, can realize the collection of each parameter in the running state of magnetic suspension system under the limited circumstances of control chip's inside sampling passageway, has saved the sampling passageway.

Specifically, when N is 5, 5 paths of displacement signals are collected through one sampling channel, such as an ADC channel, which can effectively solve the problem that only part of signals of the magnetic suspension system can be sampled due to the limited ADC sampling channel of the control chip; the ADC sampling channel of the control chip is effectively saved, the ADC sampling channel is used for sampling and feeding back more signals in real time, the sampling channel is saved, all signals in the operation process of the magnetic suspension system can be collected, and the operation reliability is improved.

Moreover, in the scheme of the utility model, 5 paths of displacement signals are collected through a sampling channel such as an ADC channel, so that the problems of communication delay and further influence on control speed and operation precision caused by the fact that an external ADC sampling chip or other control chips are used for sampling can be effectively solved; external time delay is not introduced, the control speed and the control effect are improved, and the operation reliability of the magnetic suspension system is improved. Therefore, the influence of the time delay between chips on a control loop is eliminated, and the control speed and the control effect are improved.

In some embodiments, the sampling signal comprises: the sampled signal is shifted.

Each of the sampling modules includes: two displacement sampling modules (such as displacement sensors) and one differential module (such as a differential circuit).

Each sampling module samples one path of signal in N paths of signals to be sampled to obtain a sampling signal of the one path of signal, and the sampling module comprises:

the two paths of displacement sampling modules are configured to collect displacement signals at two positions of the equipment to be controlled under one degree of freedom to obtain two paths of displacement signals.

And the differential module is configured to perform differential processing on the two paths of displacement signals to obtain a path of displacement sampling signal.

Specifically, the displacement signal output by the 2 displacement detection probes of each degree of freedom is differentially output to a path of displacement signal through a differential circuit. Fig. 6 is a schematic structural diagram of an embodiment of the displacement sampling apparatus of the present invention. As shown in fig. 6, the displacement signals FX1_ OUTPUT and FX2_ OUTPUT are differentiated to OUTPUT the displacement signals FX _ OUTPUT, and the 5 paths of displacement signals are combined into 1 path by the adder circuit, and then sampled by the amplitude conditioning circuit and the ADC sampling channel ADCINT1 to enter the control chip.

In some embodiments, the excitation sources of the N sampling modules are different in the N degrees of freedom. And under each degree of freedom, the excitation sources of the two paths of displacement sampling modules are the same. In the example shown in fig. 6, 5 excitation sources with different frequencies (obtained by controlling the chip pins to simulate high and low levels of different frequencies) are respectively used for 10 probes, that is, the excitation sources of 2 displacement detection probes with each degree of freedom are the same, and the frequency of the FX excitation source is f1, the frequency of the FY excitation source is f2, the frequency of the RX excitation source is f3, the frequency of the RY excitation source is f4, and the frequency of the AZ excitation signal source is f 5.

Each of the displacement sampling modules includes: LC resonant network model.

In the example shown in FIG. 6, an FX degree of freedom 2 displacement probe comprises: 1 resonant circuit composed of an inductor L1 and a capacitor C1, and 1 resonant circuit composed of an inductor L2 and a capacitor C2. A 2 displacement probe in FY degrees of freedom comprising: 1 resonant circuit composed of an inductor L3 and a capacitor C3, and 1 resonant circuit composed of an inductor L4 and a capacitor C4.

Thus, the utility model discloses a scheme provides a magnetic suspension system displacement detection scheme, and 5 displacement sensor use 5 different frequency's simulation PWM ripples as excitation signal respectively, become 1 way signal with these 5 way displacement sensor's output signal through the adder circuit, through ADC sampling entering control chip, through Fourier transform and inverse transform in the chip, draw the displacement signal that 5 degrees of freedom correspond in proper order, carry out displacement control.

In some embodiments, the mixing unit comprises: an addition module (e.g., a summing circuit).

The mixing unit is used for mixing the sampling signals of the N paths of signals to obtain a path of mixed sampling signal, and comprises: the adding module is configured to add the sampling signals of the N paths of signals to obtain a path of mixed sampling signal.

In the example shown in fig. 6, the addition circuit includes: a resistor R1, a resistor R2, a resistor R3 and a comparator. And the non-inverting input end of the comparator is used for receiving the sampling signals of the N paths of signals. The non-inverting input terminal of the comparator is grounded through a resistor R3. The inverting input end of the comparator is grounded after passing through the resistor R2, and is also connected with the output end of the comparator after passing through the resistor R1. And the output end of the comparator is used for outputting one path of mixed sampling signal.

In some embodiments, the processing, by the control chip, one path of the mixed sampling signal includes:

the control chip is specifically configured to perform fourier transform on one path of the mixed sampling signal to obtain a first transform signal.

The control chip is specifically configured to perform inverse fourier transform on the first transform signal according to a frequency of an excitation source of the sampling signal of the N channels of signals, so as to extract the sampling signal of the N channels of signals in the one channel of mixed sampling signal.

Fig. 8 is a schematic control logic diagram of a magnetic levitation system according to an embodiment of the present invention, specifically a schematic control logic diagram taking FX as an example. As shown in fig. 8, the control logic of the magnetic levitation system includes:

and step 1, the displacement sampling signal P _ OUTPUT enters a control logic after the DSP.

And 2, performing Fourier transform F (jw).

And 3, taking f1 as a target frequency, and performing inverse Fourier transform.

In the example shown in fig. 8, the control logic after the shift sampling signal P _ OUTPUT enters the DSP, which is described by taking FX as an example, and the rest of the 4-way shift signals are the same. And after the P _ OUTPUT is sampled by one ADC channel and enters a DSP chip, carrying out Fourier transform on the signal to obtain a frequency domain signal corresponding to the signal, and carrying out inverse Fourier transform on the signal by taking f1 as a target frequency to obtain an FX displacement signal, wherein the displacement signal is used for displacement loop control. The other 4 paths of displacement signals are extracted in the same way.

In some embodiments, further comprising: an amplitude modulation unit (such as an amplitude conditioning circuit). The amplitude modulation unit is arranged between the mixing unit and the control chip.

The amplitude modulation unit is configured to perform amplitude modulation processing on one path of the mixed sampling signal output by the mixing unit, so that the amplitude of the one path of the mixed sampling signal output by the mixing unit is conditioned to be within a set amplitude range, and then the one path of the mixed sampling signal is output to one path of the sampling channel in the control chip.

In the example shown in fig. 6, the displacement sampling apparatus includes: the device comprises a current vortex displacement sensor resonant circuit model, a differential circuit, an adding circuit, an amplitude conditioning circuit and a control chip. For example: 5 paths of displacement signals output by 5 degrees of freedom are output to a 1 path of ADC sampling channel ADCINT1 of the control chip after passing through a 1 path of adding circuit and a 1 path of amplitude conditioning circuit.

Fig. 7 is a schematic structural diagram of an embodiment of an amplitude modulation circuit according to an embodiment of the present invention. As shown in fig. 7, an amplitude modulation circuit includes: comparator, resistor R and resistor R'. The shift signal FX1_ OUTPUT is input to the inverting input of the comparator. The shift signal FX2_ OUTPUT is input to the non-inverting input terminal of the comparator. The inverting input end of the comparator is connected to the output end of the comparator after passing through the resistor R. The non-inverting input end of the comparator is grounded GND after passing through the resistor R'. The OUTPUT terminals of the comparators OUTPUT the shift signals FX1_ OUTPUT and FX2_ OUTPUT after being differentiated, and then OUTPUT the shift signals FX _ OUTPUT. The positive power end of the comparator is connected with the direct current power supply + Vcc. And the negative power end of the comparator is connected with a direct current power supply-Vcc.

Fig. 7 shows the amplitude conditioning circuit in the solution shown in fig. 6, which corrects the amplitude of the input displacement signal only according to the pin voltage of the control chip.

The utility model discloses an in the scheme, 5 way displacement signals are gathered through an ADC passageway, can effectively solve 5 way displacement signals and need 5 way filtering, amplifier circuit that correspond and increase the problem of controller cost and volume, practice thrift controller volume, reduce cost.

In some embodiments, further comprising: the control chip is also configured to control the device to be controlled according to the sampling signals of the N paths of signals extracted from the one path of mixed sampling signal. The equipment to be controlled comprises a magnetic suspension system, in particular a magnetic suspension control system.

Therefore, the utility model discloses a scheme, with necessary 5 way displacement signals in the active magnetic suspension control system sample like ADC sampling channel through a sampling channel, like this 5 way signals of separating through Fourier transform and inverse transform according to this in control chip inside through handling, carry out corresponding displacement control again.

Through a large amount of tests verification, adopt the technical scheme of the utility model, sample through an ADC passageway through the multichannel sampling signal to magnetic suspension system, this multichannel sampling signal of separating according to this through Fourier transform and anti-transform in that control chip is inside, carry out corresponding control to multichannel sampling signal again. Therefore, the multi-channel sampling signals are mixed and sampled and then separated by utilizing one internal sampling channel of the control chip, and the acquisition of each parameter in the running state of the magnetic suspension system can be realized under the condition that the internal sampling channel of the control chip is limited.

According to the utility model discloses an embodiment still provides a magnetic suspension system corresponding to signal detection device. The magnetic levitation system may include: the signal detection device described above.

Since the processing and functions of the magnetic levitation system of the present embodiment substantially correspond to the embodiments, principles, and examples of the apparatus, reference may be made to the related descriptions in the embodiments without being detailed in the description of the present embodiment, which is not described herein again.

Through a large amount of tests verification, adopt the technical scheme of the utility model, sample through an ADC passageway through the multichannel sampling signal to magnetic levitation system, this multichannel sampling signal is according to this separation through Fourier transform and anti-transform in control chip inside, carries out corresponding control to multichannel sampling signal again, practices thrift the sampling channel, is favorable to gathering all signals of magnetic levitation system operation in-process, improves the operational reliability.

According to the embodiment of the present invention, there is also provided a signal detection method of a magnetic suspension system corresponding to the magnetic suspension system, as shown in fig. 9, which is a schematic flow diagram of an embodiment of the method of the present invention. The signal detection method of the magnetic levitation system can comprise the following steps: step S110 to step S130.

In step S110, each of the N sampling modules samples one of the N signals to be sampled, so as to obtain a sampling signal of the one signal.

In some embodiments, the sampling signal comprises: the sampled signal is shifted. Each of the sampling modules includes: two displacement sampling modules (such as displacement sensors) and one differential module (such as a differential circuit).

In step S110, a specific process of obtaining a sampling signal of one of the N signals to be sampled by sampling one of the N signals through each of the sampling modules is described in the following exemplary description.

Referring to fig. 10, the flow diagram of an embodiment of the method for sampling one of the N signals to be sampled according to the present invention further illustrates a specific process of sampling one of the N signals to be sampled according to step S110, including: step S210 and step S220.

Step S210, collecting displacement signals at two positions under one degree of freedom of the equipment to be controlled through two paths of displacement sampling modules to obtain two paths of displacement signals.

And step S220, carrying out differential processing on the two paths of displacement signals through one path of differential module to obtain one path of displacement sampling signals.

And under N degrees of freedom, the excitation sources of the N sampling modules are different. And under each degree of freedom, the excitation sources of the two paths of displacement sampling modules are the same. In the example shown in fig. 6, 5 excitation sources with different frequencies (obtained by controlling the chip pins to simulate high and low levels of different frequencies) are respectively used for 10 probes, that is, the excitation sources of 2 displacement detection probes with each degree of freedom are the same, and the frequency of the FX excitation source is f1, the frequency of the FY excitation source is f2, the frequency of the RX excitation source is f3, the frequency of the RY excitation source is f4, and the frequency of the AZ excitation signal source is f 5.

Each of the displacement sampling modules includes: LC resonant network model.

In step S120, the sampling signals of the N channels of signals are mixed by a mixing unit, so as to obtain a channel of mixed sampling signals.

In step S120, the mixing unit performs mixing processing on the sampling signals of the N channels of signals to obtain a channel of mixed sampling signals, including: and adding the sampling signals of the N paths of signals through the addition module to obtain a path of mixed sampling signal.

In step S130, the control chip receives one of the channels of the mixed sampling signal through one of the channels of the control chip itself, and processes one of the channels of the mixed sampling signal to extract N channels of the sampling signal from one of the channels of the mixed sampling signal.

Specifically, when N is 5, 5 paths of displacement signals are collected through one sampling channel, such as an ADC channel, which can effectively solve the problem that only part of signals of the magnetic suspension system can be sampled due to the limited ADC sampling channel of the control chip. The ADC sampling channel of the control chip is effectively saved, the ADC sampling channel is used for sampling and feeding back more signals in real time, the sampling channel is saved, all signals in the operation process of the magnetic suspension system can be collected, and the operation reliability is improved.

In some embodiments, in step S130, a specific process of processing one path of the mixed sampling signal by the control chip is described in the following exemplary description.

Referring to fig. 11, a schematic flow chart of an embodiment of the method of the present invention for processing one path of the mixed sampling signal further illustrates a specific process of processing one path of the mixed sampling signal in step S130, including: step S310 and step S320.

Step S310, Fourier transform is carried out on one path of the mixed sampling signal through a control chip to obtain a first transform signal.

Step S320, performing inverse fourier transform on the first transform signal according to the frequency of the excitation source of the sampling signal of the N channels of signals by using the control chip, so as to extract the sampling signal of the N channels of signals in the one channel of mixed sampling signals.

And 2, performing Fourier transform F (jw).

In some embodiments, further comprising: and amplitude modulation processing is carried out on one path of mixed sampling signal output by the mixing unit through an amplitude modulation unit, so that the amplitude of the one path of mixed sampling signal output by the mixing unit is regulated to a set amplitude range and then output to one path of sampling channel in the control chip.

In some embodiments, further comprising: and controlling the equipment to be controlled through a control chip according to the sampling signals of the N paths of signals extracted from one path of mixed sampling signals. The equipment to be controlled comprises a magnetic suspension system, in particular a magnetic suspension control system.

Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the magnetic levitation system, the description of this embodiment is not detailed, and reference may be made to the related descriptions in the embodiments, which are not repeated herein.

After a large number of tests, by adopting the technical scheme of the embodiment, the multichannel sampling signals of the magnetic suspension system are sampled through one ADC channel, the multichannel sampling signals are sequentially separated through Fourier transform and inverse transform in the control chip, and then the multichannel sampling signals are correspondingly controlled, so that the influence of time delay between chips on a control loop is eliminated, and the control speed and the control effect are improved.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A signal detection device, comprising: the device comprises a sampling unit, a mixing unit and a control chip; the sampling unit includes: the number of the sampling modules is N, the N sampling modules are arranged in parallel, and N is a positive integer; wherein the content of the first and second substances,

each of the N sampling modules is configured to sample one of the N signals to be sampled to obtain a sampled signal of the one signal;

the mixing unit is configured to mix the sampling signals of the N channels of signals to obtain a channel of mixed sampling signal;

2. The signal detection device of claim 1, wherein the sampling signal comprises: shifting the sampling signal;

each of the sampling modules includes: two paths of displacement sampling modules and one path of difference module;

the two paths of displacement sampling modules are configured to collect displacement signals at two positions of the equipment to be controlled under one degree of freedom to obtain two paths of displacement signals;

3. The signal detection device according to claim 2, wherein the excitation sources of the N sampling modules are different in the N degrees of freedom; under each degree of freedom, the excitation sources of the two paths of displacement sampling modules are the same;

each of the displacement sampling modules includes: LC resonant network model.

4. The signal detection device according to claim 1, wherein the mixing unit includes: an addition module;

the mixing unit is used for mixing the sampling signals of the N paths of signals to obtain a path of mixed sampling signal, and comprises:

the adding module is configured to add the sampling signals of the N paths of signals to obtain a path of mixed sampling signal.

5. The signal detection device of claim 1, wherein the control chip processes one of the mixed sampling signals, and comprises:

performing Fourier transform on one path of the mixed sampling signal to obtain a first transform signal;

and carrying out inverse Fourier transform on the first transform signal according to the frequency of the excitation source of the sampling signals of the N paths of signals so as to extract the sampling signals of the N paths of signals in the mixed sampling signals.

6. The signal detection device according to any one of claims 1 to 5, characterized by further comprising: an amplitude modulation unit; wherein the content of the first and second substances,

the amplitude modulation unit is configured to perform amplitude modulation processing on one path of the mixed sampling signal output by the mixing unit, so that after the amplitude of the one path of the mixed sampling signal output by the mixing unit is conditioned to be within a set amplitude range, the mixed sampling signal is output to one path of the sampling channel in the control chip.

7. The signal detection device according to any one of claims 1 to 5, characterized by further comprising:

the control chip is also configured to control the device to be controlled according to the sampling signals of the N paths of signals extracted from the one path of mixed sampling signal.

8. A magnetic levitation system, comprising: the signal detection device according to any one of claims 1 to 7.