Nuclear magnetic resonance gyroscope software control system based on Raspberry Pi platform

Abstract

The invention provides a nuclear magnetic resonance gyroscope software control system based on a Raspberry Pi platform. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform comprises a PT1000 temperature measurement resistor, an A / D conversion module, a D / A conversion module, a non-magnetic electric heating piece, a heating and heat preservation structure, a temperature transmitting circuit, a power amplification circuit and the Raspberry Pi platform, and the PT1000 temperature measurement resistor and the non-magnetic electric heating piece are both connected to a nuclear magnetic resonance gyroscope. The PT1000 temperature measuring resistor is connected with the Raspberry Pi platform through the temperature transmitting circuit and the A / D conversion module. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform has the advantages that a regulation and control processing unit is replaced by the Raspberry Pi platform, measurement, processing and control of signals are achieved, the control system has multiple different control functions, and integrated design of a nuclear magnetic resonance gyroscope system can be conveniently carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of signal control and quantum devices, and in particular to a nuclear magnetic resonance gyroscope software control system based on a Raspberry Pi platform. Background Art

[0002] As a new type of quantum inertial sensor device, the Nuclear Magnetic Resonance Gyroscope (NMRG) has the advantages of high precision, small size, and low power consumption. It can support the development of future intelligent and miniaturized transportation equipment such as drones, unmanned vehicles, and robots, and is now the focus of research in various countries.

[0003] The core components of the NMR gyroscope include an atomic gas chamber that stores alkali metal and inert gas atoms, a three-dimensional magnetic field coil that generates a magnetic field, a laser system that polarizes atoms, and a non-magnetic temperature control system that heats atoms. The stability of the optical, magnetic, thermal and other physical field parameters in the gyroscope directly restricts the performance indicators of the gyroscope, so it is necessary to build a corresponding closed-loop software system to perform feedback control and signal detection processing on each parameter.

[0004] The existing closed-loop control systems of nuclear magnetic resonance gyroscopes are often bulky due to their complex structural design, which limits their portability and flexibility in practical applications. At the same time, the control systems generally have single functions and poor compatibility. They cannot realize complex control functions and are difficult to integrate with other devices or systems, which limits the universal applicability of gyroscopes in different scenarios. In addition, the operational complexity of the system also restricts the development of gyroscopes. Users need professional knowledge to effectively configure and maintain them, which not only increases the cost of use, but also reduces the user experience. These problems seriously hinder the development of nuclear magnetic resonance gyroscopes in the direction of miniaturization, integration, and convenience, limiting their application potential in future intelligent and miniaturized devices, and calling for fundamental improvements and innovations in the control systems of nuclear magnetic resonance gyroscopes to achieve their broader application prospects.

[0005] As an embedded software development platform, Raspberry Pi has almost all the functions of a personal computer, and it is also small in size, rich in external communication interfaces, low in power consumption and cost, easy to use and stable in performance. It is a representative of the new generation of small processing systems. Developing a nuclear magnetic resonance gyro control system based on the Raspberry Pi platform can achieve the construction of a multifunctional control system while maintaining the advantages of the gyro's high precision and small size, effectively improve the efficiency of system development and iteration, reduce system R&D costs, and promote the miniaturization and integration of nuclear magnetic resonance gyro control systems.

[0006] Therefore, it is necessary to provide a new nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform to solve the above technical problems. Summary of the invention

[0007] The technical problem solved by the present invention is to provide a nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform that can solve the problems of high complexity, large size, high cost, and difficult operation of previous control systems. The control processing unit is replaced by a Raspberry Pi platform to realize signal measurement, processing, and control. In addition, this control system has a variety of different control functions, which can facilitate the integrated design of the nuclear magnetic resonance gyroscope system.

[0008] To solve the above technical problems, the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention includes a PT1000 temperature measuring resistor, an A / D conversion module, a D / A conversion module, a non-magnetic electric heating plate, a heating and insulation structure, a temperature transmission circuit, a power amplifier circuit and a Raspberry Pi platform. The PT1000 temperature measuring resistor and the non-magnetic electric heating plate are both connected to the nuclear magnetic resonance gyroscope, the PT1000 temperature measuring resistor is connected to the Raspberry Pi platform through the temperature transmission circuit and the A / D conversion module, and the Raspberry Pi platform is then connected to the non-magnetic electric heating plate through the A / D conversion module and the power amplifier to form a closed-loop control.

[0009] Preferably, implementing feedback control of the atomic gas chamber temperature includes the following steps:

[0010] Step 1A: extracting the temperature information of the atomic gas chamber by using the PT1000 temperature measuring resistor, and inputting the temperature information of the gas chamber into the Raspberry Pi platform through the temperature transmitter circuit and the A / D conversion module;

[0011] Step 2A: running a temperature control algorithm on the Raspberry Pi platform, using a PID control algorithm, obtaining a temperature feedback control signal through algorithm solution processing, and outputting the control signal to the power amplifier circuit through the A / D conversion module;

[0012] Step 3A: The obtained feedback control signal is transmitted to the non-magnetic electric heating plate, and the feedback control of the air chamber temperature is realized through the non-magnetic electric heating plate.

[0013] Preferably, it also includes a low-pass filter and a voltage-controlled current source. The alkali metal magnetometer embedded in the nuclear magnetic resonance gyroscope is connected to the Raspberry Pi platform through the low-pass filter. The Raspberry Pi platform is connected to the three-axis magnetic field coil of the nuclear magnetic resonance gyroscope through the voltage-controlled current source to form a closed-loop control.

[0014] Preferably, implementing the magnetic field feedback control comprises the following steps:

[0015] Step 1B: extracting three-dimensional magnetic field information using the alkali metal magnetometer embedded in the gyroscope, and inputting the low-frequency magnetic field information into the Raspberry Pi platform using the low-pass filter;

[0016] Step 2B: running a magnetic field control algorithm on the Raspberry Pi platform, using a PID control algorithm, obtaining a magnetic field feedback control signal through algorithm solution processing, and outputting the signal to the voltage-controlled current source;

[0017] Step 3B: Convert the output signal into a feedback control current and transmit it to the three-axis magnetic field coil of the gyroscope to achieve feedback control of the three-dimensional magnetic field.

[0018] Preferably, it further comprises a signal detector and a filter, wherein the signal detector is connected to the Raspberry Pi platform, and the Raspberry Pi platform is connected to the filter to form a closed-loop system.

[0019] Preferably, the signal detection and processing are implemented, including the following steps:

[0020] Step 1C: using the signal detector to obtain gyro information, and inputting the photoelectric signal containing the gyro rotation information into the Raspberry Pi platform;

[0021] Step 2C: The Raspberry Pi platform combines the written closed-loop control and signal processing program to measure the phase and frequency information of the input signal, and extracts the effective output information of the gyroscope;

[0022] Step 3C: After extracting the effective information of the gyroscope, the Raspberry Pi platform reasonably configures the parameters of the filter in the program according to actual usage requirements, thereby achieving effective output of the gyroscope signal.

[0023] The advantages of the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention compared with the prior art are:

[0024] 1) The nuclear magnetic resonance gyroscope control system based on the Raspberry Pi platform proposed in the present invention overcomes the problems of large size, complex structure, and inconvenient operation of the previous closed-loop control system with the help of the Raspberry Pi platform, and helps the integration and miniaturization of the nuclear magnetic resonance gyroscope;

[0025] 2) The nuclear magnetic resonance gyroscope control system based on the Raspberry Pi platform proposed in the present invention uses the Raspberry Pi platform to process signals, which changes the previous control system mode in which each function is processed separately, and realizes multiple functions through parallel processing with the help of a single control platform, thereby improving the efficiency of system control and promoting the practical application of the nuclear magnetic resonance gyroscope.

[0026] 3) The nuclear magnetic resonance gyroscope control system based on the Raspberry Pi platform proposed in the present invention uses the Raspberry Pi as the signal processing and control center. The programmability of the Raspberry Pi enables the processing system to improve and iterate the program according to different control requirements, thereby improving the optimization and iteration efficiency of the control system and ensuring the advancement of the nuclear magnetic resonance gyroscope control system.

[0027] 4) The signal detection and processing system proposed in the present invention uses Raspberry Pi to perform unified signal modulation and intelligent adjustment of filter parameters, accurately determine the effective signal input of the nuclear magnetic resonance gyroscope, and effectively avoid the complicated process of trying to optimize multiple parameters one by one during the gyroscope signal acquisition process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A control system operation structure block diagram of the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention;

[0029] Figure 2 A block diagram of a temperature feedback control system of a nuclear magnetic resonance gyroscope software control system based on a Raspberry Pi platform provided by the present invention;

[0030] Figure 3 A block diagram of a magnetic field feedback control system of a nuclear magnetic resonance gyro software control system based on a Raspberry Pi platform provided by the present invention;

[0031] Figure 4 A block diagram of a closed-loop control system transfer function of a nuclear magnetic resonance gyroscope software control system based on a Raspberry Pi platform provided by the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0033] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 ,in, Figure 1 A control system operation structure block diagram of the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention; Figure 2 A block diagram of a temperature feedback control system of a nuclear magnetic resonance gyroscope software control system based on a Raspberry Pi platform provided by the present invention; Figure 3 A block diagram of a magnetic field feedback control system of a nuclear magnetic resonance gyro software control system based on a Raspberry Pi platform provided by the present invention; Figure 4 The closed-loop control system transfer function block diagram of the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform includes the following modules: PT1000 temperature measuring resistor, A / D conversion module, D / A conversion module, non-magnetic electric heating plate, heating and insulation structure, temperature transmission circuit, power amplifier circuit, low-pass filter, Raspberry Pi platform, voltage-controlled current source, signal detector, filter, Raspberry Pi platform.

[0034] PT1000 thermistor, measuring the temperature of the alkali metal gas chamber;

[0035] The temperature transmitter circuit collects the resistance value of the thermistor and converts it into an analog voltage value through signal conditioning;

[0036] A / D conversion module, collects the voltage value of the temperature measurement module and converts it into a digital signal;

[0037] The Raspberry Pi platform, as the central control platform of the entire control system, reads the input signals collected from different input terminals, analyzes and processes them centrally, and then outputs the corresponding feedback adjustment instructions to the corresponding modules. For input signals related to temperature and magnetic field, the Raspberry Pi platform will execute the packaged PID control algorithm to adjust the temperature and magnetic field to the preset stable values. For the signal of gyroscope rotation information, the Raspberry Pi system will combine the written closed-loop control and signal processing program to measure the phase and frequency information of the input signal, and extract the effective output information of the gyroscope;

[0038] D / A conversion module, which converts the PID control signal generated by the Raspberry Pi platform into an analog signal;

[0039] Power amplifier circuit: converts the obtained voltage control signal into a current control signal to drive the heater and adjust the temperature of the gas chamber;

[0040] Non-magnetic heating sheet, a special non-magnetic heating sheet wound in double layers in parallel, is used for high-frequency AC non-magnetic heating of alkali metal gas chambers;

[0041] A low-pass filter receives the signal from the alkali metal magnetometer inside the gyroscope and converts it into low-frequency magnetic field information;

[0042] Voltage-controlled current source, the PID control signal generated by the Raspberry Pi platform is converted into feedback control current and transmitted to the three-axis magnetic field coil of the gyroscope;

[0043] The signal detector obtains the gyroscope information and inputs the photoelectric signal containing the gyroscope rotation information into the Raspberry Pi platform;

[0044] Filter to achieve effective output of gyroscope signal.

[0045] The technical principle of the closed-loop control function of this system is: through different measurement modules and information transmission devices, the analog voltage signal is converted into a digital signal through the A / D conversion module; the digital signal is transmitted to the Raspberry Pi platform through the interface; the Raspberry Pi platform calculates the corresponding PID controller digital control signal through the packaged established feedback control program and the corresponding feedback control target; the digital control signal is converted into an analog signal through the D / A conversion module; the signal is transmitted to the corresponding control module to achieve precise control of the relevant parameters of the nuclear magnetic resonance gyroscope.

[0046] The specific implementation steps of atomic gas chamber temperature feedback control are as follows: Figure 2As shown in the figure, the temperature control process first collects the voltage value converted from the measured thermistor resistance through the data acquisition channel of the Raspberry Pi platform, converts it into a temperature value through the written conversion program, and compares it with the set temperature value. The difference is PI-controlled to output a feedback DC voltage value to the temperature control circuit. After being converted into an AC voltage signal of a certain frequency by the waveform generation chip, the voltage signal is converted into a current signal again through the temperature control circuit with an integrated power amplifier and input to the heating plate. The thermistor senses the temperature change caused by the current change of the heating plate, and then outputs the corresponding voltage change value to the Raspberry Pi platform. Finally, the actual temperature value reaches the set temperature value and remains stable, realizing feedback control.

[0047] The specific implementation steps of magnetic field feedback control are as follows: Figure 3 As shown, firstly, the information extraction of the three-dimensional magnetic field in the nuclear magnetic resonance gyroscope can be realized based on the embedded alkali metal magnetometer, and the low-frequency magnetic field information that needs to be compensated and controlled can be further obtained with the help of a low-pass filter. Then the obtained low-frequency magnetic field information is input into the Raspberry Pi platform, and the magnetic field feedback control program written on the Raspberry Pi platform is run to output the feedback control signal. Finally, the feedback control current is output to the three-axis magnetic field coil of the gyroscope in combination with the voltage-controlled current source to realize the feedback compensation and control of the three-dimensional magnetic field, and the feedback compensation effect can be verified with the help of a fluxgate or an embedded alkali metal magnetometer.

[0048] The technical principle of the signal detection and processing function of this system is that the Raspberry Pi uses a packaged program to read the signal related to the rotation information, and adjusts the parameters of each filter through the system to achieve effective signal output.

[0049] The specific steps of signal detection and processing are as follows: Figure 4 As shown in the figure, the Raspberry Pi platform uses the difference between the phase of the detection signal and the phase of the internal oscillator as a parameter. When the gyroscope finally reaches a steady state, the phase difference between the phase of the detection signal and the phase of the internal oscillator is basically zero, and the active tracking of the phase is completed accordingly. The frequency tracking and detection can be further realized by combining the sampling rate and the number of samples. In addition, in order to realize the closed-loop control system of the gyroscope, it is necessary to further use the phase of the real-time output of the phase-locked loop as the phase of the transverse alternating field, multiply it by the fixed output amplitude, and output it to the x-axis magnetic field coil to generate a transverse alternating field, so as to unify the phase of the spins of the atomic nuclei of each inert gas, realize the macroscopic precession effect of the atomic ensemble, and form a closed loop after reaching a steady state, completing the construction of a closed-loop control system.

[0050] Using Raspberry Pi as the information processing center greatly reduces the complexity of the system. The system is easy to operate, the control is precise and fast, and the signal reading and processing are efficient and accurate, which can better achieve the expected results.

[0051] Compared with the related art, the nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform provided by the present invention has the following beneficial effects:

[0052] The present invention provides a nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform. The Raspberry Pi itself has many advantages such as mature hardware system, strong scalability, rich software resources, small size, low power consumption, low cost, etc. The Raspberry Pi is used to realize the control of the nuclear magnetic resonance gyroscope system, and the control function of the Raspberry Pi as a central controller can be maximized, and a plurality of different control instructions can be processed at the same time, thereby overcoming the pain point that the control device needs to be replaced for different control targets of the nuclear magnetic resonance gyroscope, and improving the problems such as the complexity of the system, excessive size, and difficulty in assembly caused by the original use of devices such as acquisition cards for control. In addition, the programming function of the Raspberry Pi itself enables the system to be easily updated and iterated in the future for new target requirements that may appear, realize more and more complex functions such as feedback control and signal processing, improve the iterative efficiency of system development, reduce the system R&D cost, promote the miniaturization and integration of the nuclear magnetic resonance gyroscope, and push the nuclear magnetic resonance gyroscope to practical application as soon as possible.

[0053] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A software control system for a nuclear magnetic resonance gyroscope based on a Raspberry Pi platform, characterized in that: include: PT1000 temperature measuring resistor, A / D conversion module, D / A conversion module, non-magnetic electric heating sheet, heating and heat preservation structure, temperature transmission circuit, power amplifier circuit and Raspberry Pi platform, the PT1000 temperature measuring resistor and the non-magnetic electric heating sheet are both connected to the nuclear magnetic resonance gyroscope, the PT1000 temperature measuring resistor is connected to the Raspberry Pi platform through the temperature transmission circuit and the A / D conversion module, and the Raspberry Pi platform is then connected to the non-magnetic electric heating sheet through the A / D conversion module and the power amplifier to form a closed-loop control.

2. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform according to claim 1, characterized in that: Implementing temperature feedback control of the atomic gas chamber includes the following steps: Step 1A: extracting the temperature information of the atomic gas chamber by using the PT1000 temperature measuring resistor, and inputting the temperature information of the gas chamber into the Raspberry Pi platform through the temperature transmitter circuit and the A / D conversion module; Step 2A: running a temperature control algorithm on the Raspberry Pi platform, using a PID control algorithm, obtaining a temperature feedback control signal through algorithm solution processing, and outputting the control signal to the power amplifier circuit through the A / D conversion module; Step 3A: The obtained feedback control signal is transmitted to the non-magnetic electric heating plate, and the feedback control of the air chamber temperature is realized through the non-magnetic electric heating plate.

3. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform according to claim 1, characterized in that: It also includes a low-pass filter and a voltage-controlled current source. The alkali metal magnetometer embedded in the nuclear magnetic resonance gyroscope is connected to the Raspberry Pi platform through the low-pass filter. The Raspberry Pi platform is connected to the three-axis magnetic field coil of the nuclear magnetic resonance gyroscope through the voltage-controlled current source to form a closed-loop control.

4. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform according to claim 3, characterized in that: Realizing magnetic field feedback control includes the following steps: Step 1B: extracting three-dimensional magnetic field information using the alkali metal magnetometer embedded in the gyroscope, and inputting the low-frequency magnetic field information into the Raspberry Pi platform using the low-pass filter; Step 2B: running a magnetic field control algorithm on the Raspberry Pi platform, using a PID control algorithm, obtaining a magnetic field feedback control signal through algorithm solution processing, and outputting the signal to the voltage-controlled current source; Step 3B: Convert the output signal into a feedback control current and transmit it to the three-axis magnetic field coil of the gyroscope to achieve feedback control of the three-dimensional magnetic field.

5. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform according to claim 1, characterized in that: It also includes a signal detector and a filter. The signal detector is connected to the Raspberry Pi platform, and the Raspberry Pi platform is connected to the filter to form a closed-loop system.

6. The nuclear magnetic resonance gyroscope software control system based on the Raspberry Pi platform according to claim 5, characterized in that: The signal detection and processing are realized, including the following steps: Step 1C: using the signal detector to obtain gyro information, and inputting the photoelectric signal containing the gyro rotation information into the Raspberry Pi platform; Step 2C: The Raspberry Pi platform combines the written closed-loop control and signal processing program to measure the phase and frequency information of the input signal, and extracts the effective output information of the gyroscope; Step 3C: After extracting the effective information of the gyroscope, the Raspberry Pi platform reasonably configures the parameters of the filter in the program according to actual usage requirements, thereby achieving effective output of the gyroscope signal.

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