Frequency control method, system and equipment based on rubidium atomic frequency standard, and computer readable storage medium

Abstract

The invention discloses a frequency control method, system and device based on a rubidium atomic frequency standard and a computer readable storage medium, relates to the field of frequency control, and aims to solve the problems that in traditional direct calculation method PID control, accumulative deviation occupies a large storage space, and the frequency control efficiency is high. And the accuracy, the stability and the real-time performance of the frequency output by the rubidium atomic frequency standard are poor. The method comprises the following steps: acquiring a controlled frequency signal as an input signal, and calculating a time difference sequence; calculating the slope of the time difference curve; calculating an initial control quantity of the input signal; constructing an incremental PID control algorithm model; determining a proportional-integral coefficient; and in combination with the time difference value, the initial control quantity and the proportional-integral coefficient, through an incremental PID control algorithm model, obtaining the current adjustment quantity of the input signal, and performing frequency control on the rubidium atomic frequency standard. Through the incremental PID control mode, the influence of the control frequency and amplitude on the short-term stability of the atomic clock is minimized, and the accuracy of the output frequency is improved.

Description

Background Art

[0002] An accurate frequency source is the necessary foundation for a high-precision time unification system. Due to the existence of drift characteristics, the frequency of the rubidium atomic frequency source working in a free-running state will have a frequency offset characteristic over the working time. In order to improve this characteristic of the rubidium atomic frequency standard, a higher-precision and more stable external time source signal is usually used to control the offset correction of the frequency signal of the rubidium atomic frequency standard through the driving method, so as to improve the accuracy and stability of the output frequency.

[0003] The commonly used frequency driving control method usually adopts the PID control algorithm. The PID control algorithm combines three control methods: proportional control (P), integral control (I) and differential control (D). Proportional control directly converts the deviation into the control output through the proportional gain (Kp), and the integral control integrates the deviation through the integral gain (Ki), and accumulates the integral result as part of the control output. The differential control differentiates the deviation through the differential gain (Kp), and accumulates the differential result as part of the control output. The PID controller has both the fast response of the P controller and the stability of I and D control.

[0004] The PID controller of frequency control compares the set value r(t) with the actual output value c(t) to form a control deviation, that is:

[0005] e(t)=r(t)-c(t) (1)

[0006] Then the deviation is linearly combined into a control quantity according to the proportion, integration and differentiation to control the controlled object. The principle block diagram of the conventional PID control system is shown in Figure 2.

[0007] The general PID controller algorithm is:

[0008]

[0009] Among them, K p is the proportionality coefficient, K ι is the integration coefficient, K d =K p T D , K d is the differential coefficient, T ι is the integration time constant, T D is the differential time constant, u0 is the initial control quantity;

[0010] Its digital control equation is:

[0011]

[0012] Among them, u(k) is the output value when the sequence number is k, and e(k) is the time difference value when the sequence number is k.

[0013] It can be seen from the above formula that every calculation requires the participation of all control quantities, and every output of the control quantity is related to all past states, which takes up a large storage space. Therefore, a new PID control method needs to be provided. Summary of the invention

[0014] The present specification provides a frequency steering control method, system, device, and computer-readable storage medium based on a rubidium atomic frequency standard, which is used to solve the problem that the accumulated deviation in the traditional direct calculation method PID control occupies a large storage space, thereby resulting in poor accuracy, stability, and real-time performance of the frequency output by the rubidium atomic frequency standard.

[0015] To achieve the above object, the present invention adopts the following technical solution:

[0016] In a first aspect of the present specification, a frequency steering control method based on a rubidium atomic frequency standard is provided, the method comprising the following steps:

[0017] Acquire a controlled frequency signal as an input signal; calculate a set of time difference sequences between historical input signals and reference signals as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source;

[0018] In combination with the historical time difference sequence model, the slope of the time difference curve is calculated by using the least square method; in combination with the slope of the time difference curve and the time difference value in the historical time difference sequence model, the initial control amount of the input signal is calculated;

[0019] According to the digital control equation of the PID controller algorithm, an incremental PID control algorithm model is constructed;

[0020] Determine the proportional-integral coefficient of the incremental PID control algorithm model; the proportional-integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient;

[0021] In combination with the time difference value, the initial control amount, and the proportional integral coefficient, the current adjustment amount of the input signal is obtained through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

[0022] In some preferred embodiments, a time difference sequence between a set of input signals and a reference signal is calculated by:

[0023] u(t)=KΔT(t)+b

[0024] Among them, u(t) is the output of the PID controller algorithm, K is the slope of the time difference curve, T(t) is the time difference sequence, and b is the constant term.

[0025] In some preferred embodiments, the slope of the time difference curve is calculated as follows:

[0026]

[0027] Among them, x i is the serial number of the time difference sequence, y i The serial number is x i The time difference value, n is the number of time differences in the time difference sequence, and i is the subscript.

[0028] In some preferred embodiments, the digital control equation of the PID controller algorithm is:

[0029]

[0030] Among them, u(k) is the output value when the sequence number is k, K p is the proportional coefficient, e(k) is the time difference when the serial number is k, is the integration coefficient, T ι is the integration time constant, K d =K p T D , K d is the differential coefficient, T D is the differential time constant, and u0 is the initial control quantity.

[0031] In some preferred embodiments, an incremental PID control algorithm model is constructed by:

[0032] Substituting k=k-1 into the digital control equation of the PID controller algorithm, we obtain:

[0033]

[0034] Combining the above equations with the digital control equations of the PID controller algorithm, an incremental PID control algorithm model is obtained:

[0035]

[0036] Wherein, Δu(k) is the calculated adjustment amount of the controlled frequency signal.

[0037] In some preferred embodiments, the proportional integral coefficient is determined by:

[0038] The proportional coefficient determination method is as follows: the integral coefficient and the differential coefficient are set to zero, so that the control system corresponding to the PID controller algorithm is pure proportional control, and the value of the control object is set to M% of the maximum value allowed by the control system; then, the proportional coefficient is gradually increased until oscillation occurs, and then the proportional coefficient is gradually reduced until the oscillation is less than the set oscillation threshold, the proportional coefficient at this time is recorded, and the final proportional coefficient is set to M% of the recorded proportional coefficient;

[0039] The integral coefficient determination method: after determining the proportional coefficient, set an initial integral coefficient, and gradually increase the integral coefficient until oscillation occurs, then gradually reduce the integral coefficient until the oscillation disappears, record the integral coefficient at this time, and set the final integral coefficient to be N% of the recorded integral coefficient;

[0040] The differential coefficient determination method is as follows: set it to 0 or set an initial differential coefficient, and gradually increase the differential coefficient until oscillation occurs, then gradually reduce the differential coefficient until the oscillation disappears, record the differential coefficient at this time, and set the final differential coefficient to P% of the recorded integral coefficient.

[0041] In some preferred implementations, when calculating the current adjustment amount of the input signal, the time difference value is the time difference value set before this time.

[0042] In a second aspect of the present specification, a frequency steering control system based on a rubidium atomic frequency standard is provided. Based on the above-mentioned frequency steering control method based on a rubidium atomic frequency standard, the system comprises:

[0043] The time difference calculation module is configured to obtain a controlled frequency signal as an input signal; calculate a time difference sequence between a set of historical input signals and a reference signal as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source;

[0044] A slope calculation module is configured to calculate the slope of the time difference curve by using the least square method in combination with the historical time difference series model; and calculate the initial control amount of the input signal by combining the slope of the time difference curve and the time difference value in the historical time difference series model;

[0045] A model building module is configured to build an incremental PID control algorithm model according to a digital control equation of a PID controller algorithm;

[0046] A coefficient acquisition module is configured to determine the proportional integral coefficient of the incremental PID control algorithm model; the proportional integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient;

[0047] The control module is configured to combine the time difference value, the initial control amount, and the proportional integral coefficient, and obtain the current adjustment amount of the input signal through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

[0048] The third aspect of this specification provides a frequency steering control device based on a rubidium atomic frequency standard, comprising: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned frequency steering control method based on a rubidium atomic frequency standard.

[0049] In a fourth aspect of the present specification, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned frequency steering control method based on the rubidium atomic frequency standard.

[0050] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0051] The present invention is simple to implement, and can quickly respond to the dynamic changes of the system without complicated preliminary preparation or a large amount of historical data, which greatly improves the modeling problem of a limited number of samples. More importantly, the incremental control strategy allows the system to be adjusted in a more delicate way, reducing the impact of each control action on the system. For atomic clocks that need to maintain extremely high frequency stability, this means that more accurate time signal output can be achieved without affecting its short-term stability. That is, the incremental control method minimizes the impact of the control frequency and amplitude on the short-term stability of the atomic clock, and improves the accuracy of the output frequency, achieving a 24h accuracy of the rubidium atomic clock better than 1E-12, and a stability better than 1E-13. In addition, the lower control frequency and amplitude reduce unnecessary energy consumption, thereby improving overall operating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0053] Figure 1 A flowchart of a frequency steering control method based on a rubidium atomic frequency standard provided in an embodiment of this specification;

[0054] Figure 2 This is a block diagram of the PID control principle provided in one embodiment of this specification. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0056] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0057] This manual adopts the principle of increment to establish a control model, improves the problem of the accumulated deviation occupying a large storage space in the traditional direct calculation method PID control, and realizes the frequency driving control of the rubidium atomic frequency standard. The details are as follows:

[0058] The first embodiment of this specification provides a frequency control method based on a rubidium atomic frequency standard, see Figure 1 , wherein the PID control principle block diagram of the present invention is shown in Figure 2 , specifically including:

[0059] Acquire a controlled frequency signal as an input signal; calculate a set of time difference sequences between historical input signals and reference signals as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source;

[0060] In this embodiment, a set of time difference sequences between a frequency signal with the controlled frequency as the reference source and a reference signal is accumulated to establish a historical time difference sequence model, and the model formula is:

[0061] u(t)=KΔT(t)+b (4)

[0062] Among them, u(t) is the output of the PID controller algorithm, K is the slope of the time difference curve, T(t) is the time difference sequence, and b is the constant term.

[0063] In combination with the historical time difference sequence model, the slope of the time difference curve is calculated by using the least square method; in combination with the slope of the time difference curve and the time difference value in the historical time difference sequence model, the initial control amount of the input signal is calculated;

[0064] In this embodiment, the formula for calculating the slope of the time difference curve is:

[0065]

[0066] Among them, x i is the serial number of the time difference sequence, y i The serial number is x i The time difference value, nis the number of time differences in the time difference sequence, and i is the subscript.

[0067] According to the digital control equation of the PID controller algorithm, an incremental PID control algorithm model is constructed;

[0068] In this embodiment, the process of constructing the incremental PID control algorithm model is as follows:

[0069] Substituting k=k-1 into formula (3), we get the following formula:

[0070]

[0071] From formula (3) and formula (6), the incremental PID control algorithm model is obtained, and the formula is as follows:

[0072]

[0073] Wherein, Δu(k) is the calculated adjustment amount of the controlled frequency signal.

[0074] Determine the proportional-integral coefficient of the incremental PID control algorithm model; the proportional-integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient;

[0075] In this embodiment, the proportional coefficient is determined by setting the integral coefficient and the differential coefficient to zero, so that the control system corresponding to the PID controller algorithm is pure proportional control, and the value of the control object is set to M% of the maximum value allowed by the control system; then, gradually increase the proportional coefficient until oscillation occurs, and then gradually reduce the proportional coefficient until the oscillation is less than the set oscillation threshold, record the proportional coefficient at this time, and set the final proportional coefficient to M% of the recorded proportional coefficient; M is preferably 60.

[0076] Method for determining the integral coefficient: After determining the proportional coefficient, set an initial integral coefficient and gradually increase the integral coefficient until oscillation occurs. At this time, gradually reduce the integral coefficient until the oscillation disappears. Record the integral coefficient at this time and set the final integral coefficient to N% of the recorded integral coefficient; N is preferably 55.

[0077] Method for determining the differential coefficient: Generally, it does not need to be set, just take 0; if a small oscillation occurs and cannot be optimized through the PI environment, the same method as determining the proportional and integral coefficients can be used, and the differential coefficient is taken as P% when the system is not oscillating (that is, set an initial differential coefficient and gradually increase the differential coefficient until oscillation occurs, then gradually reduce the differential coefficient until the oscillation disappears, record the differential coefficient at this time, and set the final differential coefficient to P% of the recorded integral coefficient. P is preferably 30).

[0078] In combination with the time difference value, the initial control amount, and the proportional integral coefficient, the current adjustment amount of the input signal is obtained through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

[0079] In summary, the incremental PID control algorithm model established in the present invention has greatly improved the modeling problem of a limited number of samples, is simple to implement, and the incremental control method minimizes the impact of the control frequency and amplitude on the short-term stability of the atomic clock.

[0080] The second embodiment of the present specification provides a frequency steering control system based on a rubidium atomic frequency standard. Based on the above-mentioned frequency steering control method based on a rubidium atomic frequency standard, the system includes:

[0081] The time difference calculation module is configured to obtain a controlled frequency signal as an input signal; calculate a time difference sequence between a set of historical input signals and a reference signal as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source;

[0082] A slope calculation module is configured to calculate the slope of the time difference curve by using the least square method in combination with the historical time difference series model; and calculate the initial control amount of the input signal by combining the slope of the time difference curve and the time difference value in the historical time difference series model;

[0083] A model building module is configured to build an incremental PID control algorithm model according to a digital control equation of a PID controller algorithm;

[0084] A coefficient acquisition module is configured to determine the proportional integral coefficient of the incremental PID control algorithm model; the proportional integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient;

[0085] The control module is configured to combine the time difference value, the initial control amount, and the proportional integral coefficient, and obtain the current adjustment amount of the input signal through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

[0086] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the system described above can refer to the corresponding process in the method embodiment, and will not be repeated here.

[0087] It should be noted that the frequency steering control system based on the rubidium atomic frequency standard provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be decomposed or combined. For example, the modules in the above embodiments can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps, and are not regarded as improper limitations on the present invention.

[0088] The third embodiment of the present specification provides a frequency steering control device based on a rubidium atomic frequency standard, comprising: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned frequency steering control method based on a rubidium atomic frequency standard.

[0089] The fourth embodiment of the present specification provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned frequency steering control method based on the rubidium atomic frequency standard.

[0090] Technicians in the technical field can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the frequency steering control device based on the rubidium atomic frequency standard and the computer-readable storage medium described above can refer to the corresponding process in the aforementioned system example and will not be repeated here.

[0091] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A frequency steering control method based on rubidium atomic frequency standard, characterized in that: The method comprises the following steps: Acquire a controlled frequency signal as an input signal; calculate a set of time difference sequences between historical input signals and reference signals as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source; In combination with the historical time difference sequence model, the slope of the time difference curve is calculated by using the least square method; in combination with the slope of the time difference curve and the time difference value in the historical time difference sequence model, the initial control amount of the input signal is calculated; According to the digital control equation of the PID controller algorithm, an incremental PID control algorithm model is constructed; Determine the proportional-integral coefficient of the incremental PID control algorithm model; the proportional-integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient; In combination with the time difference value, the initial control amount, and the proportional integral coefficient, the current adjustment amount of the input signal is obtained through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

2. The frequency steering control method based on rubidium atomic frequency standard according to claim 1 is characterized in that: Calculate the time difference sequence between a set of input signals and a reference signal as follows: u(t)=KΔT(t)+b Among them, u(t) is the output of the PID controller algorithm, K is the slope of the time difference curve, T(t) is the time difference sequence, and b is the constant term.

3. The frequency steering control method based on rubidium atomic frequency standard according to claim 2 is characterized in that: The slope of the time difference curve is calculated as follows: Among them, x i is the serial number of the time difference sequence, y i The serial number is x i The time difference value, n is the number of time differences in the time difference sequence, and i is the subscript.

4. The frequency steering control method based on rubidium atomic frequency standard according to claim 3 is characterized in that: The digital control equation of the PID controller algorithm is: Among them, u(k) is the output value when the sequence number is k, K p is the proportional coefficient, e(k) is the time difference when the serial number is k, K ι is the integration coefficient, T ι is the integration time constant, K d =K p T D , K d is the differential coefficient, T D is the differential time constant, and u0 is the initial control quantity.

5. The frequency steering control method based on rubidium atomic frequency standard according to claim 4 is characterized in that: The incremental PID control algorithm model is constructed by: Substituting k=k-1 into the digital control equation of the PID controller algorithm, we obtain: Combining the above equations with the digital control equations of the PID controller algorithm, an incremental PID control algorithm model is obtained: Wherein, Δu(k) is the calculated adjustment amount of the controlled frequency signal.

6. The frequency steering control method based on rubidium atomic frequency standard according to claim 1 is characterized in that: The proportional integral coefficient is determined by: The proportional coefficient determination method is as follows: the integral coefficient and the differential coefficient are set to zero, so that the control system corresponding to the PID controller algorithm is pure proportional control, and the value of the control object is set to M% of the maximum value allowed by the control system; then, the proportional coefficient is gradually increased until oscillation occurs, and then the proportional coefficient is gradually reduced until the oscillation is less than the set oscillation threshold, the proportional coefficient at this time is recorded, and the final proportional coefficient is set to M% of the recorded proportional coefficient; The integral coefficient determination method: after determining the proportional coefficient, set an initial integral coefficient, and gradually increase the integral coefficient until oscillation occurs, then gradually reduce the integral coefficient until the oscillation disappears, record the integral coefficient at this time, and set the final integral coefficient to be N% of the recorded integral coefficient; The differential coefficient determination method is as follows: set it to 0 or set an initial differential coefficient, and gradually increase the differential coefficient until oscillation occurs, then gradually reduce the differential coefficient until the oscillation disappears, record the differential coefficient at this time, and set the final differential coefficient to P% of the recorded integral coefficient.

7. The frequency steering control method based on rubidium atomic frequency standard according to claim 1 is characterized in that: When calculating the current adjustment amount of the input signal, the time difference value is the time difference value of a set time before this time.

8. A frequency steering control system based on a rubidium atomic frequency standard, based on a frequency steering control method based on a rubidium atomic frequency standard according to any one of claims 1 to 7, characterized in that: The system comprises: The time difference calculation module is configured to obtain a controlled frequency signal as an input signal; calculate a time difference sequence between a set of historical input signals and a reference signal as a historical time difference sequence model; the controlled frequency signal is a frequency signal with the controlled frequency of the rubidium atomic frequency standard as a reference source; A slope calculation module is configured to calculate the slope of the time difference curve by using the least square method in combination with the historical time difference series model; and calculate the initial control amount of the input signal by combining the slope of the time difference curve and the time difference value in the historical time difference series model; A model building module is configured to build an incremental PID control algorithm model according to a digital control equation of a PID controller algorithm; A coefficient acquisition module is configured to determine the proportional integral coefficient of the incremental PID control algorithm model; the proportional integral coefficient includes a proportional coefficient, an integral coefficient, and a differential coefficient; The control module is configured to combine the time difference value, the initial control amount, and the proportional integral coefficient, and obtain the current adjustment amount of the input signal through an incremental PID control algorithm model, thereby performing frequency steering control on the rubidium atomic frequency standard.

9. A frequency control device based on rubidium atomic frequency standard, characterized in that: include: at least one processor; and a memory communicatively coupled to at least one of the processors; The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement a frequency steering control method based on a rubidium atomic frequency standard as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the frequency steering control method based on the rubidium atomic frequency standard as described in any one of claims 1-7.

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