CN109976442B - Slave clock information optimization method and device, electronic equipment and storage medium - Google Patents

Abstract

The present invention provides a method, device, electronic device and storage medium for optimizing slave clock information. The method includes: step A, acquiring master clock information; step B, processing the master clock information through a sliding mode controller to obtain first information Step C, the first information after the interference processing is processed through the controlled object function to obtain the second information; Step D, the second information after the noise processing is processed by the Kalman filter to obtain slave clock information; Step E, judging whether the deviation of the master clock information and the slave clock information satisfies the preset condition; Step F, when the deviation of the master clock information and the slave clock information does not meet the preset condition, input the deviation of the master clock information and the slave clock information into the The sliding mode controller performs steps B-step E until the deviation between the master clock information and the slave clock information meets a preset condition, and obtains the target slave clock information. The invention reduces the master-slave clock deviation and realizes relatively accurate master-slave clock synchronization.

Description

A method, device, electronic device and storage medium for optimizing slave clock information

technical field

The present invention relates to the field of communication technologies, and in particular, to a method, device, electronic device and storage medium for optimizing slave clock information.

Background technique

In 2008, the IEEE (Institute of Electrical and Electronics Engineers, American Institute of Electrical and Electronics Engineers) protocol organization proposed the IEEE1588V2 precise time transfer protocol, which can achieve sub-microsecond precision master-slave clock synchronization, becoming the industry's most popular Time Transfer Protocol.

The prior art adopts the 1588 protocol to realize the synchronization of the master and slave clocks as follows: by rapidly exchanging messages between the slave clock and the master clock, time stamps are obtained; The drift value of the clock relative to the master clock frequency, and the slave clock is adjusted by the drift value, so as to realize the synchronization of the master and slave clock frequencies.

The inventor found that, in the existing method for realizing master-slave clock synchronization by using the 1588 protocol, the stability of the clock crystal oscillator seriously affects the IEEE 1588 clock synchronization accuracy. When the crystal oscillator is in a high temperature environment, the stability of the crystal oscillator will be greatly reduced, which is mainly manifested in the large frequency drift of the oscillator frequency of the clock crystal oscillator. If this frequency drift is not corrected in time, the master-slave clock deviation will increase over time. Therefore, how to reduce the deviation of the master-slave clocks to achieve more accurate master-slave clock synchronization is still a technical problem to be solved urgently.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present invention is to provide a method, device, electronic device and storage medium for optimizing slave clock information, so as to reduce the deviation of the master and slave clocks, thereby realizing more accurate synchronization of the master and slave clocks. The specific technical solutions are as follows:

In a first aspect, an embodiment of the present invention discloses a method for optimizing slave clock information, the method comprising:

Step A, acquiring master clock information;

Step B, the master clock information is processed by the sliding mode controller to obtain the first information;

Step C, performing interference processing on the first information, and processing the first information after the interference processing through the controlled object function to obtain second information; the controlled object function corresponds to the master clock information. The function expression of the clock information is obtained by Laplace transform and discretization;

Step D, performing noise processing on the second information, and processing the second information after the noise processing through a Kalman filter to obtain slave clock information;

Step E, judging whether the deviation of the master clock information and the slave clock information satisfies a preset condition;

Step F, when the deviation between the master clock information and the slave clock information does not meet the preset condition, input the deviation between the master clock information and the slave clock information into the sliding mode controller, and execute Steps B to E, until the deviation between the master clock information and the slave clock information satisfies a preset condition, obtain target slave clock information.

Optionally, the processing of the master clock information through a sliding mode controller to obtain the first information includes:

inputting the master clock information into the sliding mode controller, and obtaining the first intermediate value through the first formula of the sliding mode controller;

Obtain the second intermediate value through the second formula of the sliding mode controller;

A third intermediate value is obtained through the first intermediate value and the second intermediate value;

The third intermediate value is input into the third formula of the sliding mode controller, and the first information is obtained through the third formula.

Optionally, performing interference processing on the first information, and processing the first information after the interference processing through a controlled object function to obtain second information, including:

adding preset interference information to the first information to obtain the first information after interference processing;

The first information after the interference processing is processed by the controlled object function to obtain the second information; wherein, the controlled object function is expressed as:

x(k)=Ax(k-1)+B(u(k)+ω(k))

y(k)=Cx(k)

Among them, x(k) represents the state variable of the current moment; x(k-1) represents the state variable of the previous moment; u(k) represents the first information; ω(k) represents the process noise; A represents the system matrix ; B represents the input matrix; represents the output matrix; y(k) represents the second information.

Optionally, performing noise processing on the second information, and processing the second information after the noise processing through a Kalman filter to obtain slave clock information, including:

The second information is subjected to noise processing by a preset formula; the preset formula is expressed as:

y _v (k)=y(k)+v(k)

Wherein, y _v (k) represents the second information after noise processing; y(k) represents the second information; v(k) represents measurement noise;

The second information after the noise processing is calculated through the preset equation set of the Kalman filter to obtain the slave clock information.

In a second aspect, an embodiment of the present invention discloses an apparatus for optimizing slave clock information, the apparatus comprising:

The master clock information acquisition module is used to obtain the master clock information;

a first information determination module, configured to process the master clock information through a sliding mode controller to obtain first information;

The second information determination module is configured to perform interference processing on the first information, and process the first information after the interference processing through the controlled object function to obtain second information; the controlled object function is the controlled object function. The function expression of the slave clock information corresponding to the master clock information is obtained through Laplace transform and discretization;

A slave clock information determination module, configured to perform noise processing on the second information, and process the second information after the noise processing through a Kalman filter to obtain slave clock information;

a master-slave clock deviation judgment module, configured to judge whether the deviation between the master clock information and the slave clock information satisfies a preset condition;

A target slave clock information determination module, configured to input the deviation between the master clock information and the slave clock information to the The sliding mode controller returns to the first information determination module and continues to execute until the deviation between the master clock information and the slave clock information satisfies a preset condition, and obtains target slave clock information.

Optionally, the first information determination module includes:

a first intermediate value determination submodule, configured to input the master clock information to the sliding mode controller, and obtain the first intermediate value through the first formula of the sliding mode controller;

The second intermediate value determination submodule is configured to obtain the second intermediate value through the second formula of the sliding mode controller;

a third intermediate value determination submodule, configured to obtain a third intermediate value through the first intermediate value and the second intermediate value;

The first information determination sub-module is configured to input the third intermediate value into a third formula of the sliding mode controller, and obtain the first information through the third formula.

Optionally, the second information determination module includes:

an interference processing sub-module, configured to add preset interference information to the first information to obtain the first information after interference processing;

The second information determination sub-module is used to process the first information after the interference processing through the controlled object function to obtain the second information; wherein, the controlled object function is expressed as:

x(k)=Ax(k-1)+B(u(k)+ω(k))

y(k)=Cx(k)

Among them, x(k) represents the state variable of the current moment; x(k-1) represents the state variable of the previous moment; u(k) represents the first information; ω(k) represents the process noise; A represents the system matrix ; B represents the input matrix; represents the output matrix; y(k) represents the second information.

Optionally, the slave clock information determination module includes:

A noise addition processing sub-module, configured to perform noise addition processing on the second information through a preset formula; the preset formula is expressed as:

y _v (k)=y(k)+v(k)

Wherein, y _v (k) represents the second information after noise processing; y(k) represents the second information; v(k) represents measurement noise;

The slave clock information determination sub-module is configured to calculate the second information after noise processing through the preset equation set of the Kalman filter to obtain slave clock information.

In a third aspect, an embodiment of the present invention discloses an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. Communication;

the memory for storing computer programs;

The processor is configured to implement the method steps described in any one of the above methods for optimizing slave clock information when executing the program stored in the memory.

In a fourth aspect, an embodiment of the present invention discloses a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the above methods for optimizing slave clock information is implemented. a described method step.

In a method, device, electronic device, and storage medium for optimizing slave clock information provided by the embodiments of the present invention, first, a sliding mode controller is used to process the deviation between slave clock information and master clock information, so that the master-slave clock crystal oscillator can be optimized. The frequency drift is effectively controlled and optimized, and then the Kalman filter is used to process the output information of the sliding mode controller, which can effectively suppress the influence of external interference such as slave clock crystal oscillator jitter and random error, and then obtain the slave clock information and master clock. The deviation of the information satisfies the target slave clock information corresponding to the preset condition. The obtained target slave clock information reduces the oscillation frequency drift of the slave clock crystal oscillator and the influence of the slave clock crystal oscillator jitter and random error on the accuracy of the slave clock information, thereby effectively reducing the master-slave clock deviation and realizing a relatively accurate master-slave clock. Synchronize.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic diagram of a PTP delay response mechanism of the Precision Time Protocol according to an embodiment of the present invention;

2 is a flowchart of a method for optimizing slave clock information according to an embodiment of the present invention;

3 is a frame diagram of a slave clock information optimization system according to an embodiment of the present invention;

Fig. 4 is a kind of simulation comparison diagram of the processing result of adopting adding Kalman filter and not adopting Kalman filter in the prior art from the clock information optimization method according to the embodiment of the present invention;

5 is a simulation result diagram of adopting a synchronization period of T=1s in a method for optimizing slave clock information according to an embodiment of the application;

6 is a comparison diagram of simulation results of master-slave clocks in different synchronization periods in master-slave clock information according to an embodiment of the present invention;

7 is a schematic structural diagram of an apparatus for optimizing slave clock information according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the time synchronization research of the 1588 protocol, the master-slave time synchronization accuracy is related to the frequency drift, frequency jitter and random error of the clock crystal oscillator. The Kalman filter and sliding mode controller used in this application are used to realize this synchronization of the slave clock. Three factors are controlled and optimized to achieve high-precision synchronization of master and slave time.

First, the principle and influencing factors of protocol time synchronization, the principle of precise clock synchronization of PTP (Precision Time Protocol, Precision Time Protocol), and the proposed delay response mechanism are mainly divided into six steps. Refer to the schematic diagram of the PTP delay response mechanism of the Precision Time Protocol according to the embodiment of the present invention shown in FIG. 1 . In Figure 1, a is the sync synchronization message, b is the Follow_up message, c is the Delay_req delay request message, d is the Delay_resq delay request response message, the Master is the master clock, and the Slave is the slave clock. The packet sending and receiving process of the delayed response synchronization mechanism is as follows:

The master clock periodically sends out sync packets, and records the precise sending time t1 when the sync packets leave the master clock. The master clock encapsulates the precise sending time t1 into a Follow_up message and sends it to the slave clock. The slave clock records the precise arrival time t2 when the sync message arrives at the slave clock. The delay_req message is sent from the clock and the precise sending time t3 is recorded. The master clock records the precise arrival time t4 at which the delay_req message arrives at the master clock. The master clock sends a delay_resp message carrying the precise timestamp information t4 to the slave clock. The time deviation of the master and slave clocks of this mechanism is offset; the average delay of packet transmission in the network is delay; assuming that the delay of the transmission link of the synchronization packet is symmetrical, we can obtain:

According to the above two formulas, the time offset offset and the average delay delay can be obtained respectively.

The high-precision clock synchronization protocol of the 1588 protocol is based on an idealized situation. In actual network measurement and control systems, there will be many influencing factors, such as timestamp accuracy, transmission link asymmetry, and inherent jitter in network delay. , Master-slave clock crystal oscillator drift and jitter and other factors. To achieve the high-precision master-slave clock synchronization of the 1588 protocol, the two factors that have a greater impact are the asymmetry of the transmission link and the drift and jitter of the master-slave clock crystal oscillator. In the calculation of time deviation offset and average delay delay, it is assumed that the transmission link of the packet in the network is symmetrical, but in the actual network transmission will pass through switches and other devices, which will cause the packet to be transmitted in the round-trip path delay. Inequality problem. The application mainly studies the influence of the drift of the master and slave clock crystal oscillators. Therefore, according to the general control variable method, it is assumed that the transmission link of the packet in the network is symmetrical.

A method for optimizing slave clock information of the present application, based on sliding mode control and Kalman filter 1588 protocol time synchronization, effectively and organically combines sliding mode controller, Kalman filter, and 1588 protocol, which are currently hot research topics, so as to Realize higher-precision time synchronization of 1588 protocol. For the approximately linearly increasing error caused by the frequency drift of the master-slave clock crystal oscillator, the application uses sliding mode control to achieve effective control and optimization; and for the random error caused by clock frequency jitter and external interference, the application uses Kalman filtering. The device realizes the filtering of noise such as random errors and achieves effective suppression. The specific method is described in detail in the following examples.

In a first aspect, an embodiment of the present invention discloses a method for optimizing slave clock information, as shown in FIG. 2 . FIG. 2 is a flowchart of a method for optimizing slave clock information disclosed in an embodiment of the present invention. The method includes:

S201, obtain master clock information.

In the application, the master clock information is set as a standard clock source, and the time expressed by the slave clock is the time accumulation of the oscillation frequency of the local crystal oscillator. The oscillation frequency of the crystal oscillator not only depends on the inherent characteristics of the crystal oscillator's material, cut angle, shape, aging, etc., but also on its external environment such as temperature, humidity, pressure, etc. Due to the influence of factors such as ambient temperature and the aging of the crystal oscillator itself, the crystal oscillator will generate certain errors and accumulate over time, resulting in an error offset between the slave clock and the master clock, which seriously affects the synchronization accuracy. The crystal oscillator's own aging has a relatively slow effect on the crystal oscillator's frequency drift, while the ambient temperature will have a real-time impact on the crystal oscillator.

In this step, the master clock information is obtained, and the master clock information may be a specific time or an initial value customized by the implementer. Set the master clock information as: M(t)=t.

S202, the master clock information is processed by the sliding mode controller to obtain first information.

In this step, the master clock information is input to the sliding mode controller, and the frequency drift of the clock crystal oscillator is effectively controlled and optimized through the sliding mode controller based on the exponential reaching law. The input master clock information can be represented by yd.

Optionally, in S202, the master clock information is processed by the sliding mode controller to obtain the first information, including:

Step 1, input the master clock information to the sliding mode controller, and obtain the first intermediate value through the first formula of the sliding mode controller;

The first formula of the sliding mode controller is expressed as:

y _d ^(k+1)=2 y _d ^(k) -y _d ^(k-1)

Among them, y _d (k) corresponds to the position command of the current input information of the sliding mode controller, and the first input is the position command corresponding to the master clock information; y _d (k-1) corresponds to the last input information of the sliding mode controller. When the master clock information is the first input of the sliding mode controller, the implementer can set the initial value of y _d (k-1); y _d (k+1) corresponds to the next input information of the sliding mode controller position command.

The first intermediate value y _d (k+1) can be obtained by this first formula.

Step 2, obtain the second intermediate value through the second formula of the sliding mode controller;

The first formula of the sliding mode controller is expressed as:

dy _d ^(k+1)=2 dy _d ^(k) -dy _d ^(k-1)

Among them, dy _d (k) corresponds to the change rate of the position command of the current input information of the sliding mode controller; dy _d (k-1) corresponds to the change rate of the position command of the last input information of the sliding mode controller; dy _d (k+1) corresponds to the rate of change of the position command of the next input information of the sliding mode controller.

The second intermediate values y _d (k+1) and dy _d (k) can be obtained through the second formula.

Step 3: Obtain a third intermediate value through the first intermediate value and the second intermediate value.

In this step, Y _d =[y _d (k)dy _d (k)] ^T and Y _d1 =[y _d (k+1)dy _d (k+1)] ^T are calculated, and the switching function s(k )=C _e (Y _d -x).

Step 4: Input the third intermediate value into the third formula of the sliding mode controller, and obtain the first information through the third formula.

The third formula of the sliding mode controller is expressed as:

u(k)=(C _e B) ^-1 (C _e Y _d1 -C _e Ax(k)-s(k)-ds(k))

Among them, u(k) represents the first information obtained by the sliding mode control of the exponential reaching law; C _e represents the sliding mode controller coefficient matrix, which satisfies the Hurwitz condition, C _e =[c 1], c is a constant and c>0; B represents the input matrix; Y _d1 =[y _d (k+1)dy _d (k+1)] ^T ; A represents the system matrix; x(k) represents the information input to the sliding mode controller, the first time Master clock information, and later the deviation between slave clock information and master clock information; s(k) represents the switching function, s(k)=C _e (Y _d -x); ds(k)=-εTsgn(s(k ))-qTs(k), ε represents, T represents the synchronization period of the message, sgn() represents the step function, and q represents the exponential term coefficient.

S203, performing interference processing on the first information, and processing the first information after the interference processing through the controlled object function to obtain second information; the controlled object function corresponds to the function expression of the slave clock information corresponding to the master clock information through The Laplace transform and the discretized function.

The controlled object function in this step is a process in which the output changes due to the state and input, and the information output by the sliding mode controller is optimized through the controlled object function to obtain the second information.

The transfer function of the controlled object is obtained by performing Laplace transform from the functional expression of the clock information and discretizing it.

The functional expression of the slave clock information is:

为受温度影响从时钟信号的频率偏移率，u(t)为产生的随机误差。in,

is the frequency offset rate of the slave clock signal affected by temperature, and u(t) is the random error generated.

The controlled object transfer function of the sliding mode controller system can be obtained by performing Laplace transform from the functional expression of the clock information,

Among them, s and S ² represent the variables after Laplace transformation; discrete sampling is performed according to the above formula, for example, the sampling time Ts is 0.001s, and the above formula is discretized as the controlled object function of the application.

Optionally, in S203, interference processing is performed on the first information, and the first information after the interference processing is processed through the controlled object function to obtain second information, including:

Step a, adding preset interference information to the first information to obtain first information after interference processing.

In this step, the preset interference information w is added to the first information, and the first information after interference processing can be expressed as u(k)=u(k)+wn(k).

Step b, the first information after the interference processing is processed by the controlled object function to obtain the second information; wherein, the controlled object function is expressed as:

x(k)=Ax(k-1)+B(u(k)+ω(k))

y(k)=Cx(k)

Among them, x(k) represents the state variable of the current moment; x(k-1) represents the state variable of the previous moment; u(k) represents the first information; ω(k) represents the process noise; A represents the system matrix; B represents the input matrix; C represents the output matrix; y(k) represents the second information.

S204 , performing noise addition processing on the second information, and processing the second information after the noise addition processing through a Kalman filter to obtain a slave clock signal.

In this step, Kalman filtering is used to effectively suppress the influence of external disturbances such as clock crystal oscillator jitter and random errors.

Optionally, in S204, noise processing is performed on the second information, and the second information after the noise processing is processed by a Kalman filter to obtain slave clock information, including:

Step 1), performing noise processing on the second information through a preset formula; the preset formula is expressed as:

y _v (k)=y(k)+v(k)

Wherein, y _v (k) represents the second information after noise processing; y(k) represents the second information; v(k) represents the measurement noise.

Step 2), calculating the second information after the noise addition processing through the preset equation system of the Kalman filter to obtain the slave clock information.

The preset equation system for this Kalman filter is expressed as:

x(k)=Ax(k-1)+M _n (k)(y _v (k)-CAx(k-1))

y _e (k)=Cx(k)

表示k时刻的先验估计协方差的中间计算结果；R表示；P(k-1)表示；Q表示过程激励噪声协方差；x(k)表示卡尔曼滤波器的当前时刻状态方程；y_v(k)表示加噪处理后的第二信息；x(k-1)表示卡尔曼滤波器的上一时刻状态方程；y_e(k)表示输出的从时钟信息，在形式上可用ye表示。Among them, M _n (k) represents the gain of mixing factor or residual; A represents the system matrix; B represents the matrix of input variables; C represents the output matrix; P(k) represents the posterior estimated covariance;

Represents the intermediate calculation result of the prior estimated covariance at time k; R represents; P(k-1) represents; Q represents the process excitation noise covariance; x(k) represents the current state equation of the Kalman filter; y _v (k) represents the second information after noise processing; x(k-1) represents the state equation of the Kalman filter at the last moment; y _e (k) represents the output slave clock information, which can be represented by ye in form.

S205: Determine whether the deviation between the master clock information and the slave clock information satisfies a preset condition.

In the embodiment of the present invention, the preset condition is a preset value close to zero, and the specific value is set by the implementer. In this step, it is judged whether the deviation between the slave clock information and the master clock information is equal to or less than a threshold. That is to judge whether the difference between the master clocks yd-ye is equal to or smaller than the threshold. The physical meaning of the difference between yd-ye is the time offset offset between the master and slave clocks:

S206, when the deviation between the master clock information and the slave clock information does not meet the preset condition, input the deviation between the master clock information and the slave clock information to the sliding mode controller, and execute S202-S205 until the deviation between the master clock information and the slave clock information is reached When the preset conditions are met, the target slave clock information is obtained.

When it is determined in the above S205 that the difference between yd and ye is greater than the threshold, the difference between yd and ye is input to the sliding mode controller, and the execution of S202 to S205 is continued until the difference between yd and ye is equal to or less than the threshold. . Taking the corresponding slave clock information at this time as the target slave clock information, it shows that the influence of the frequency offset rate and random error on the accuracy of the slave clock is optimized at this time. Master and slave clock synchronization.

In a method for optimizing slave clock information provided by an embodiment of the present invention, first, a sliding mode controller is used to process the deviation between the slave clock information and the master clock information, so as to effectively control and optimize the frequency drift of the master and slave clock crystal oscillators. Then the Kalman filter is used to process the output information of the sliding mode controller, which can effectively suppress the influence of external interference such as slave clock crystal oscillator jitter and random error, and then obtain the corresponding deviation between the slave clock information and the master clock information that meets the preset conditions. The target slave clock information. The obtained target slave clock information reduces the oscillation frequency drift of the slave clock crystal oscillator and the influence of the slave clock crystal oscillator jitter and random error on the accuracy of the slave clock information, thereby effectively reducing the master-slave clock deviation and realizing a more accurate master-slave clock. Synchronize.

In order to better illustrate a method for optimizing slave clock information of the present invention, there may be a frame diagram of a system for optimizing slave clock information according to an embodiment of the present invention as shown in FIG. 3 .

In the embodiment of the present invention, firstly, the master clock information yd is input to the sliding mode controller, and the first information is obtained by processing by the sliding mode controller; the control disturbance w is added to the first information, and the first information after the control disturbance is added. The first information is processed by the controlled object function to obtain the second information; the measurement noise v is added to the second information processed from the controlled object function, and the second information after adding the measurement noise v is input into the Kalman filter; The Kalman filter processes the information, and outputs the slave clock information ye; calculates the difference between yd-ye and determines whether the difference between yd-ye meets the preset conditions, and when the difference between yd-ye does not meet the preset conditions , input the difference of yd-ye to the sliding mode controller, and repeat the above steps until the preset condition of the difference of yd-ye is reached, and the value of ye at this time is used as the target slave clock information.

The advantages of the embodiments of the present invention may be described below by using simulink simulation.

输入矩阵

输入矩阵C＝[1 0]；传输矩阵D＝0；白噪声信号ω(k)为[-0.8 0.8]；白噪声信号v(k)为[-0.001 0.001]，卡尔曼滤波器中过程激励噪声协方差Q＝10；观察噪声协方差R＝10；滑模控制器中，系数矩阵C_e中的常数c＝25；趋近切换面的速率ε＝130；指数项系数q＝280；设置初始的主时钟信息与从时钟信息的偏差为0.000001s；主时钟信息与从时钟信息的偏差阈值为10us；将主时钟信息与从时钟信息的偏差offset加卡尔曼滤波器与未加时卡尔曼滤波器的结果进行对比，该比较图可参见图4。图4为本发明实施例的一种从时钟信息优化方法中采用加卡尔曼滤波器与现有技术中未采卡尔曼滤波器处理结果仿真对比图。图4中offset1表示本申请的加卡尔曼滤波器的结果，offset2表示现有技术未加卡尔曼滤波器即自然状态下的结果。Aiming at a method for optimizing slave clock information of the present application, a system matrix can be set

input matrix

Input matrix C=[1 0]; transmission matrix D=0; white noise signal ω(k) is [-0.8 0.8]; white noise signal v(k) is [-0.001 0.001], the process excitation in Kalman filter Noise covariance Q=10; observation noise covariance R=10; in sliding mode controller, constant c=25 in coefficient matrix C _e ; rate of approaching switching surface ε=130; exponential term coefficient q=280; setting The deviation between the initial master clock information and the slave clock information is 0.000001s; the deviation threshold between the master clock information and the slave clock information is 10us; the offset between the master clock information and the slave clock information is added with Kalman filter and Kalman without time addition. The results of the filters are compared, and the comparison diagram can be seen in Figure 4. FIG. 4 is a simulation comparison diagram of a processing result of a slave clock information optimization method using a Kalman filter and a Kalman filter not used in the prior art according to an embodiment of the present invention. In FIG. 4 , offset1 represents the result of adding the Kalman filter of the present application, and offset2 represents the result in the natural state without adding the Kalman filter in the prior art.

It can be seen from Figure 4 that when the master and slave clocks are not synchronized, the time deviation increases approximately linearly and is accompanied by a small jitter, but after filtering through the Kalman filter, the curve becomes obviously smoother, and the jitter is even smaller , the jitter of the time deviation is significantly suppressed. It can be seen that the Kalman filter used in this application has a certain effect on improving the master-slave time synchronization accuracy of the 1588 protocol.

When a synchronization period of T=1s is used, the result diagram of a method for optimizing slave clock information according to the present application can be seen in FIG. 5 . FIG. 5 is a simulation result diagram of adopting a synchronization period of T=1s in a method for optimizing slave clock information according to an embodiment of the present application.

It can be seen from Fig. 5 that, in the slave clock information optimization method of the present application, through the processing of Kalman filter and sliding mode controller, the master-slave time offset offset is not only effectively suppressed by the approximate linear increase caused by clock frequency drift and Optimization, and the random error caused by the jitter of the slave clock frequency is also well controlled, so that the offset quickly converges to a minimum value within 5s, the curve becomes smoother, and remains largely stable. It can be seen that, in the slave clock information optimization method of the present application, the scheme of improving the master-slave time synchronization accuracy of the 1588 protocol through the sliding mode controller and the Kalman filter has great practicability and feasibility.

The master-slave clock information of three different synchronization periods (T1=0.1s, T2=0.5s, T3=1.0s) is processed by using the slave clock information optimization method of the present application, and the result comparison diagram shown in FIG. 6 can be obtained. FIG. 6 is a comparison diagram of simulation results of master-slave clocks in different synchronization periods in master-slave clock information according to an embodiment of the present invention.

It can be seen from Fig. 6 that when the synchronization period T3=1s, it converges rapidly within about 5s; when T2=0.5s, it converges rapidly within about 3s; when T1=0.1s, it converges rapidly within about 2s. That is to say, with the continuous reduction of the packet synchronization period, the faster the master-slave time offset converges, and the higher the time synchronization accuracy is. The slave clock information optimization method of the present application, based on the Kalman filter and the sliding mode controller, can effectively control the rate of the slave clock for signals of different synchronization periods, so that it can quickly follow the master clock and achieve better time synchronization accuracy, thereby Realize the control and optimization of different master-slave clock synchronization cycles of the 1588 protocol, improve the accuracy of time synchronization, and meet the nanosecond-level requirements of 5G (5G network, fifth-generation mobile communication network) for time synchronization.

In a second aspect, an embodiment of the present invention discloses an apparatus for optimizing slave clock information, as shown in FIG. 7 . 7 is a schematic structural diagram of an apparatus for optimizing slave clock information according to an embodiment of the present invention, and the apparatus includes:

a master clock information obtaining module 701, configured to obtain master clock information;

a first information determination module 702, configured to process the master clock information through the sliding mode controller to obtain the first information;

The second information determination module 703 is configured to perform interference processing on the first information, and process the first information after the interference processing through the controlled object function to obtain the second information; the controlled object function corresponds to the slave clock information corresponding to the master clock information. The function expression of the clock information is obtained by Laplace transform and discretization;

The slave clock information determining module 704 is configured to perform noise processing on the second information, and process the second information after the noise processing through a Kalman filter to obtain slave clock information;

The master-slave clock deviation judgment module 705 is used to judge whether the deviation between the master clock information and the slave clock information satisfies a preset condition;

The target slave clock information determination module 706 is used to input the deviation between the master clock information and the slave clock information to the sliding mode controller when the deviation between the master clock information and the slave clock information does not meet the preset condition, and return to the first information determination module to continue The execution is performed until the deviation between the master clock information and the slave clock information satisfies the preset condition, and the target slave clock information is obtained.

Optionally, in an embodiment of the apparatus for optimizing slave clock information of the present invention, the first information determining module 702 includes:

The first intermediate value determination submodule is used to input the master clock information to the sliding mode controller, and obtain the first intermediate value through the first formula of the sliding mode controller;

The second intermediate value determination submodule is used to obtain the second intermediate value through the second formula of the sliding mode controller;

The third intermediate value determination submodule is used to obtain the third intermediate value through the first intermediate value and the second intermediate value;

The first information determination sub-module is configured to input the third intermediate value into the third formula of the sliding mode controller, and obtain the first information through the third formula.

Optionally, in an embodiment of the apparatus for optimizing slave clock information of the present invention, the second information determining module 703 includes:

an interference processing sub-module, configured to add preset interference information to the first information to obtain the first information after interference processing;

The second information determination sub-module is used to process the first information after the interference processing through the controlled object function to obtain the second information; wherein, the controlled object function is expressed as:

x(k)=Ax(k-1)+B(u(k)+ω(k))

y(k)=Cx(k)

Among them, x(k) represents the state variable of the current moment; x(k-1) represents the state variable of the previous moment; u(k) represents the first information; ω(k) represents the process noise; A represents the system matrix; B represents the input matrix; represents the output matrix; y(k) represents the second information.

Optionally, in an embodiment of the apparatus for optimizing slave clock information of the present invention, the slave clock information determining module 704 includes:

The noise addition processing sub-module is used to perform noise addition processing on the second information through a preset formula; the preset formula is expressed as:

y _v (k)=y(k)+v(k)

Wherein, y _v (k) represents the second information after noise processing; y(k) represents the second information; v(k) represents the measurement noise;

The slave clock information determination sub-module is used for calculating the second information after the noise addition processing through the preset equation set of the Kalman filter to obtain the slave clock information.

In a third aspect, an embodiment of the present invention discloses an electronic device, as shown in FIG. 8 . 8 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, including a processor 801 , a communication interface 802 , a memory 803 and a communication bus 804 , wherein the processor 801 , the communication interface 802 , and the memory 803 communicate with each other through the communication bus 804 Communication;

a memory 803 for storing computer programs;

The processor 801 is configured to implement any one of the above-mentioned methods for optimizing the slave clock information when executing the program stored in the memory 803 .

The communication bus 804 mentioned in the above electronic device may be a peripheral component interconnect standard (Peripheral Component Interconnect, PCI) bus or an Extended Industry Standard Architecture (Extended Industry Standard Architecture, EISA) bus or the like. The communication bus 804 can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

The communication interface 802 is used for communication between the above electronic device and other devices.

The memory 803 may include random access memory (Random Access Memory, RAM), and may also include non-volatile memory (Non-Volatile Memory, NVM), such as at least one disk storage. Optionally, the memory 803 may also be at least one storage device located away from the aforementioned processor 801 .

The above-mentioned processor 801 may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; it may also be a digital signal processor (Digital Signal Processing, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

In an electronic device provided by an embodiment of the present invention, a sliding mode controller is used to first process the deviation between the slave clock information and the master clock information, so as to effectively control and optimize the frequency drift of the crystal oscillator of the master and slave clocks, and then use Karl The Mann filter processes the output information of the sliding mode controller, which can effectively suppress the influence of external interference such as slave clock crystal oscillator jitter and random error, and then obtain the target slave clock corresponding to the deviation between the slave clock information and the master clock information meeting the preset conditions. clock information. The obtained target slave clock information reduces the oscillation frequency drift of the slave clock crystal oscillator and the influence of the slave clock crystal oscillator jitter and random error on the accuracy of the slave clock information, thereby effectively reducing the master-slave clock deviation and realizing a relatively accurate master-slave clock. Synchronize.

In a fourth aspect, an embodiment of the present invention discloses a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the above-mentioned methods for optimizing slave clock information is implemented. .

In the computer-readable storage medium provided by the embodiment of the present invention, the deviation between the slave clock information and the master clock information is first processed by the sliding mode controller, so that the frequency drift of the master and slave clock crystal oscillators can be effectively controlled and optimized, Then the Kalman filter is used to process the output information of the sliding mode controller, which can effectively suppress the influence of external interference such as slave clock crystal oscillator jitter and random error, and then obtain the corresponding deviation between the slave clock information and the master clock information that meets the preset conditions. The target slave clock information. The obtained target slave clock information reduces the oscillation frequency drift of the slave clock crystal oscillator and the influence of the slave clock crystal oscillator jitter and random error on the accuracy of the slave clock information, thereby effectively reducing the master-slave clock deviation and realizing a relatively accurate master-slave clock. Synchronize.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions according to the embodiments of the present invention result in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device. Computer instructions may be stored on or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server, or data center over a wire (e.g. coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.) to another website site, computer, server, or data center. A computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, or the like that includes an integration of one or more available media. Useful media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk (SSD)), among others.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or device that includes the element.

Each embodiment in this specification is described in a related manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. Especially, for the embodiments of the apparatus, electronic equipment and storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and reference may be made to some descriptions of the method embodiments for related parts.

The above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for slave clock information optimization, the method comprising:

step A, acquiring master clock information;

b, processing the master clock information through a sliding mode controller to obtain first information;

step C, carrying out interference processing on the first information, and processing the first information subjected to the interference processing through a controlled object function to obtain second information; the controlled object function is a function obtained by performing Laplace transform and discretization on a function expression of slave clock information corresponding to the master clock information;

step D, carrying out noise adding processing on the second information, and processing the second information subjected to the noise adding processing through a Kalman filter to obtain slave clock information;

step E, judging whether the deviation of the master clock information and the slave clock information meets a preset condition or not;

and F, when the deviation between the master clock information and the slave clock information does not meet the preset condition, inputting the deviation between the master clock information and the slave clock information into the sliding mode controller, and executing the steps B to E until the deviation between the master clock information and the slave clock information meets the preset condition, so as to obtain target slave clock information.

2. The method of claim 1, wherein processing the master clock information through a sliding mode controller to obtain first information comprises:

inputting the main clock information into a sliding mode controller, and obtaining a first intermediate value through a first formula of the sliding mode controller;

obtaining a second intermediate value through a second formula of the sliding mode controller;

obtaining a third intermediate value according to the first intermediate value and the second intermediate value;

and inputting the third intermediate value into a third formula of the sliding mode controller, and obtaining first information through the third formula.

3. The method according to claim 1, wherein the performing interference processing on the first information and processing the first information after the interference processing by a controlled object function to obtain second information comprises:

adding preset interference information to the first information to obtain the first information subjected to interference processing;

processing the first information subjected to interference processing through a controlled object function to obtain second information; wherein the controlled object function is represented as:

x(k)＝Ax(k-1)+B(u(k)+ω(k))

y(k)＝Cx(k)

wherein x (k) represents a state variable at the current time; x (k-1) represents a state variable at the last time; u (k) represents the first information; ω (k) represents process noise; a represents a system matrix; b represents an input matrix; representing an output matrix; y (k) represents the second information.

4. The method according to claim 1, wherein the denoising the second information and processing the denoised second information through a kalman filter to obtain slave clock information comprises:

denoising the second information through a preset formula; the preset formula is expressed as:

y_v(k)＝y(k)+v(k)

wherein, y_v(k) Representing the second information after the noise adding processing; y (k) represents the second information; v (k) represents measurement noise;

and calculating the second information subjected to the noise adding treatment through a preset equation set of a Kalman filter to obtain slave clock information.

5. A slave clock information optimization apparatus, the apparatus comprising:

the master clock information acquisition module is used for acquiring master clock information;

the first information determining module is used for processing the master clock information through a sliding mode controller to obtain first information;

the second information determining module is used for carrying out interference processing on the first information and processing the first information subjected to the interference processing through a controlled object function to obtain second information; the controlled object function is a function obtained by performing Laplace transform and discretization on a function expression of slave clock information corresponding to the master clock information;

the slave clock information determining module is used for carrying out noise adding processing on the second information and processing the second information subjected to the noise adding processing through a Kalman filter to obtain slave clock information;

the master-slave clock deviation judging module is used for judging whether the deviation of the master clock information and the slave clock information meets a preset condition or not;

and the target slave clock information determining module is used for inputting the deviation of the master clock information and the slave clock information into the sliding mode controller when the deviation of the master clock information and the slave clock information does not meet the preset condition, returning to the first information determining module and continuing to execute until the deviation of the master clock information and the slave clock information meets the preset condition, and obtaining target slave clock information.

6. The apparatus of claim 5, wherein the first information determining module comprises:

the first intermediate value determining submodule is used for inputting the main clock information into the sliding mode controller and obtaining a first intermediate value through a first formula of the sliding mode controller;

the second intermediate value determining submodule is used for obtaining a second intermediate value through a second formula of the sliding mode controller;

a third intermediate value determining submodule, configured to obtain a third intermediate value through the first intermediate value and the second intermediate value;

and the first information determining submodule is used for inputting the third intermediate value into a third formula of the sliding mode controller, and obtaining first information through the third formula.

7. The apparatus of claim 5, wherein the second information determining module comprises:

the interference processing submodule is used for adding preset interference information to the first information to obtain the first information after interference processing;

the second information determining submodule is used for processing the first information subjected to interference processing through a controlled object function to obtain second information; wherein the controlled object function is represented as:

x(k)＝Ax(k-1)+B(u(k)+ω(k))

y(k)＝Cx(k)

wherein x (k) represents a state variable at the current time; x (k-1) represents a state variable at the last time; u (k) represents the first information; ω (k) represents process noise; a represents a system matrix; b represents an input matrix; c represents an output matrix; y (k) represents the second information.

8. The apparatus of claim 5, wherein the slave clock information determining module comprises:

the noise adding processing submodule is used for adding noise to the second information through a preset formula; the preset formula is expressed as:

y_v(k)＝y(k)+v(k)

wherein, y_v(k) Representing the second information after the noise adding processing; y (k) represents the second information; v (k) represents measurement noise;

and the slave clock information determination submodule is used for calculating the second information subjected to the noise adding processing through a preset equation set of a Kalman filter to obtain slave clock information.

9. An electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory complete communication with each other through the communication bus;

the memory is used for storing a computer program;

the processor, when executing the program stored in the memory, implementing the method steps of any of claims 1-4.

10. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, which computer program, when being executed by a processor, carries out the method steps of any one of claims 1 to 4.

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