A method for detecting frequency of dynamic measurement signal of drilling tool

Abstract

The present invention discloses a method for detecting the frequency of a drill tool dynamic measurement signal, comprising: collecting drill tool dynamic signal data; performing high-frequency signal detection on the drill tool dynamic signal data using a variable-scale tristable chaotic system; performing full-phase frequency detection on the drill tool dynamic signal data using an array tristable chaotic system; and combining the variable-scale tristable chaotic system and the array tristable chaotic system to simultaneously detect the drill tool dynamic signal data. The present invention utilizes an array tristable chaotic detection system, which is unaffected by the initial phase angle of the drill tool measurement signal, thereby solving the problem of frequency detection of the drill tool measurement signal. Phase change technology is used to effectively solve the problem of frequency detection of the drill tool measurement signal under mixed frequency conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of signal detection, and in particular to a method for detecting the frequency of a dynamic measurement signal of a drilling tool. Background Art

[0002] Digital filters based on time-frequency analysis were first applied to noise suppression in the dynamic measurement signals of drill guide tools. A ground decoding system uses FIR digital filters to reduce noise on mud pulse signals. However, due to the diversity of interference sources, the frequency distribution of noise signals in actual sensor signals is highly complex, inevitably overlapping with the measured signal frequency. Therefore, while suppressing noise, the useful signal is inevitably corrupted, even rendering the dynamic measurement of the drill guide tool ineffective.

[0003] A nonlinear model for drill tool attitude measurement based on quaternions is used, and an unscented Kalman filter algorithm is applied to filter out noise interference. However, due to the complex downhole drilling environment, the modeling process is subject to numerous uncertainties, such as sudden changes in system parameters, transient interference, unknown noise statistical characteristics, and unknown measurement drift. These factors can lead to reduced accuracy of the unscented Kalman filter estimation and even filter divergence, rendering the optimal estimate invalid. Therefore, dynamic measurement methods based on multi-sensor combined measurement and optimal estimation algorithms have inevitable drawbacks and limitations.

[0004] The phase changes of the existing tristable chaotic system can successfully detect weak signals in a strong noise background. However, when it is applied to the frequency detection of the dynamic measurement signal of the drill guide tool, the angular frequency of the signal to be measured is not a constant value, but changes continuously based on the drill speed. The change in the driving signal frequency will change the size of the critical amplitude when the system undergoes phase change, which makes it difficult to apply the frequency detection of the tristable chaotic system. When the angular frequency of the driving signal is too large, the system is not prone to chaos and large-scale periodic states, resulting in a deterioration of the system's dynamic response characteristics. When the drill tool is drilling normally, the system's dynamic response characteristics deteriorate, seriously affecting the accuracy and feasibility of frequency detection. Summary of the Invention

[0005] An embodiment of the present invention provides a method for detecting the frequency of a dynamic measurement signal of a drilling tool, which is used to solve the problem in the prior art that when a tristable chaotic system is applied to the frequency detection of the dynamic measurement signal of a drilling tool, the angular frequency of the signal to be measured is not a constant value, but changes continuously based on the drill tool rotation speed. The change in the frequency of the driving signal will change the size of the critical amplitude when the system undergoes a phase change, which makes it difficult to apply the frequency detection of the tristable chaotic system; when the angular frequency of the driving signal is too large, the system is not prone to chaos and large-scale periodic states, resulting in a deterioration in the dynamic response characteristics of the system. When the drill tool is drilling normally, the dynamic response characteristics of the system deteriorate, which seriously affects the accuracy and feasibility of frequency detection.

[0006] In one aspect, an embodiment of the present invention provides a method for detecting the frequency of a dynamic measurement signal of a drilling tool, comprising:

[0007] Collect dynamic signal data of drilling tools;

[0008] Performing high-frequency signal detection on the drilling tool dynamic signal data by using a variable-scale tristable chaotic system;

[0009] Performing full-phase frequency detection of the drilling tool dynamic signal data through an array tristable chaotic system;

[0010] The variable-scale tristable chaotic system and the array tristable chaotic system are combined to simultaneously detect the dynamic signal data of the drilling tool.

[0011] In a possible implementation, the high-frequency signal detection of the drilling tool dynamic signal data using a variable-scale tristable chaotic system includes:

[0012] Reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal;

[0013] Inputting the reconstructed signal into the variable-scale tristable chaotic system for iterative calculation;

[0014] The frequency of the reconstructed signal is identified according to the change of the output phase state of the variable-scale tristable chaotic system.

[0015] In a possible implementation, reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal includes:

[0016] Introducing a variable scale coefficient into the drill tool dynamic signal data to restore the angular frequency value of the drill tool dynamic signal data to be measured;

[0017] The frequency reconstruction of the drilling tool dynamic signal data is achieved by adjusting the step size of the numerical calculation.

[0018] In a possible implementation, performing full-phase frequency detection on the drilling tool dynamic signal data by using an array tristable chaotic system includes:

[0019] The tristable chaotic system is expanded into an array tristable chaotic system by adjusting the initial phase angle.

[0020] Substituting the drilling tool dynamic signal data into the array tristable chaotic system obtains the full phase frequency of the drilling tool dynamic signal data to be measured.

[0021] In a possible implementation, combining the variable-scale tristable chaotic system and the array tristable chaotic system to simultaneously detect the drilling tool dynamic signal data includes:

[0022] An array tristable chaotic system is obtained by setting the initial phase angle of the drilling tool dynamic signal data;

[0023] Inputting the dynamic signal data and noise of the drilling tool to be measured into the array tristable chaotic system;

[0024] reconstructing the angular frequency and sampling frequency of the dynamic signal data by using the scaling coefficient;

[0025] Solving the array tristable chaotic system through the reconstructed calculation step size;

[0026] The variable scale coefficient is adjusted to complete the detection of the drilling tool dynamic signal data.

[0027] In a possible implementation, adjusting the variable scaling coefficient to complete the detection of the drilling tool dynamic signal data includes:

[0028] Observing the output phase trajectory of the array tristable chaotic system after adjusting the variable scaling coefficient;

[0029] The angular frequency of the drilling tool dynamic signal data is determined according to the output phase trajectory and the value of the variable scaling coefficient.

[0030] In a possible implementation, the expansion of the tristable chaotic system into an array tristable chaotic system by adjusting the initial phase angle is to divide the initial phase angle into three intervals and substitute them into the expression of the tristable chaotic system to obtain the array tristable chaotic system composed of three different driving equations.

[0031] The method for detecting the frequency of a dynamic measurement signal of a drilling tool in the present invention has the following advantages:

[0032] (1) The frequency detection problem of the drilling tool measurement signal is solved by using the array tristable chaos detection system, which is not affected by the initial phase angle of the drilling tool measurement signal.

[0033] (2) Phase change technology is used to effectively solve the frequency detection problem of drilling tool measurement signals under mixed frequency conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A flowchart of a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0036] Figure 2 A diagram showing the overall change of state with amplitude of a typical tristable chaotic system solution for a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0037] Figure 3 A diagram showing the state of a typical tristable chaotic system solution for a method for detecting the frequency of a drilling tool dynamic measurement signal provided by an embodiment of the present application, with the amplitude varying from chaos to large-scale periodic local changes;

[0038] Figure 4 A typical tristable chaotic system output phase chaotic state diagram of a typical tristable chaotic system solution of a drilling tool dynamic measurement signal frequency detection method provided in an embodiment of the present application;

[0039] Figure 5 A large-scale periodic state diagram of the output phase state of a typical tristable chaotic system of a typical tristable chaotic system solution for a method for detecting the frequency of a drilling tool dynamic measurement signal provided in an embodiment of the present application;

[0040] Figure 6 A schematic diagram of a detectable window corresponding to the initial phase angle of an array tristable chaotic system of a typical tristable chaotic system solution for a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0041] Figure 7 A flowchart of a typical tristable chaotic system solution for a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0042] Figure 8 A trajectory diagram of the output phase of an array tristable chaotic system without adding a signal to be measured, which is a typical tristable chaotic system solution of a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0043] Figure 9 This is a trajectory diagram of the output phase K=1,γ=-120° of the array tristable chaotic system of a typical tristable chaotic system solution of a method for detecting the frequency of a drilling tool dynamic measurement signal provided by an embodiment of the present application;

[0044] Figure 10 This is a trajectory diagram of the output phase K=10, γ=0° of a typical tristable chaotic system solution of a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided in an embodiment of the present application;

[0045] Figure 11 This is a trajectory diagram of the array tristable chaotic system output phase K=1,γ=120° of a typical tristable chaotic system solution of a drilling tool dynamic measurement signal frequency detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Figure 1 A flowchart of a method for detecting the frequency of a dynamic measurement signal of a drilling tool provided by an embodiment of the present invention is provided. The method for detecting the frequency of a dynamic measurement signal of a drilling tool provided by an embodiment of the present invention includes:

[0048] Collect dynamic signal data of drilling tools;

[0049] Performing high-frequency signal detection on the drilling tool dynamic signal data by using a variable-scale tristable chaotic system;

[0050] Performing full-phase frequency detection of the drilling tool dynamic signal data through an array tristable chaotic system;

[0051] The variable-scale tristable chaotic system and the array tristable chaotic system are combined to simultaneously detect the dynamic signal data of the drilling tool.

[0052] The high-frequency signal detection of the drilling tool dynamic signal data by using the variable-scale tristable chaotic system includes:

[0053] Reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal;

[0054] Inputting the reconstructed signal into the variable-scale tristable chaotic system for iterative calculation;

[0055] The frequency of the reconstructed signal is identified according to the change of the output phase state of the variable-scale tristable chaotic system.

[0056] Reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal includes:

[0057] Introducing a variable scale coefficient into the drill tool dynamic signal data to restore the angular frequency value of the drill tool dynamic signal data to be measured;

[0058] The frequency reconstruction of the drilling tool dynamic signal data is achieved by adjusting the step size of the numerical calculation.

[0059] The full-phase frequency detection of the drilling tool dynamic signal data by using the array tristable chaotic system includes:

[0060] The tristable chaotic system is expanded into an array tristable chaotic system by adjusting the initial phase angle.

[0061] Substituting the drilling tool dynamic signal data into the array tristable chaotic system obtains the full phase frequency of the drilling tool dynamic signal data to be measured.

[0062] The step of combining the variable-scale tristable chaotic system and the array tristable chaotic system to simultaneously detect the dynamic signal data of the drilling tool includes:

[0063] An array tristable chaotic system is obtained by setting the initial phase angle of the drilling tool dynamic signal data;

[0064] Inputting the dynamic signal data and noise of the drilling tool to be measured into the array tristable chaotic system;

[0065] Reconstructing the angular frequency and sampling frequency of the dynamic signal data by using the scaling coefficient;

[0066] Solving the array tristable chaotic system through the reconstructed calculation step size;

[0067] The variable scale coefficient is adjusted to complete the detection of the drilling tool dynamic signal data.

[0068] The adjusting the variable scale coefficient to complete the detection of the drilling tool dynamic signal data includes:

[0069] Observing the output phase trajectory of the array tristable chaotic system after adjusting the variable scaling coefficient;

[0070] The angular frequency of the drilling tool dynamic signal data is determined according to the output phase trajectory and the value of the variable scaling coefficient.

[0071] The method of expanding the tristable chaotic system into an array tristable chaotic system by adjusting the initial phase angle is to divide the initial phase angle into three intervals and substitute them into the expression of the tristable chaotic system to obtain the array tristable chaotic system composed of three different driving equations.

[0072] Exemplarily, the large-frequency signal detection using the variable-scale tristable chaotic system includes:

[0073] The typical tristable chaotic system is shown in formula (1):

[0074] (1)

[0075] Where x is the solution of the tristable chaotic system, which is a function of time t; k is the damping coefficient, which is generally 0.5; (-x+x 3 +x 5 ) is the nonlinear restoring force; Asinωt is the driving signal, A and ω are the amplitude and angular frequency of the driving signal, respectively, and ω=1rad / s.

[0076] Due to the existence of nonlinear restoring force, the state of the tristable chaotic system solution changes regularly with the increase of the driving signal amplitude A, and successively experiences homoclinic orbit, bifurcation, chaos and large-scale periodic state. The law of change of the state of the system solution with the amplitude A is as follows: Figure 2 、 3 It can be seen that the critical amplitude of the typical tristable chaotic system from the chaotic state to the large-scale periodic state is 0.588.

[0077] When the solution of the system is in the critical state of transition from chaos to large-scale periodicity, the system is very sensitive to the amplitude A, and a small change can cause a significant change in the system output phase. Therefore, A is adjusted to the critical value Ac of the transition from chaos to large-scale periodicity, and the same-frequency signal to be measured s(t) and noise n(t) are added to formula (1). The weak signal detection model based on the tristable chaotic system is obtained as shown in formula (2):

[0078] (2)

[0079] The tristable chaotic system is placed in the critical state of the transition from chaotic state to large-scale periodic state, and the signal s(t)+n(t) is used as the input of the system in this state. The frequency value of the measured signal s(t) can be detected by the phase trajectory obtained by formula (2). The output phase state of a typical tristable chaotic system is as follows: Figure 4 、 5 As shown, the vertical coordinate y represents x'.

[0080] from Figure 4 、 5 As can be seen from the changes in , since the measured signal and the driving signal have the same angular frequency, the input of the measured signal can increase the driving signal amplitude and exceed the critical value Ac, causing a significant change in the system output phase. Furthermore, although the input signal contains noise interference n(t), it does not affect the change in the system output phase, only causing roughness at the boundaries of large-scale periodic states, demonstrating that this method is immune to noise. This is the basic principle of using a typical tristable chaotic system to detect the frequency of the measured signal.

[0081] Now, assume that the expression of the drilling tool dynamic measurement signal is as follows:

[0082] (3)

[0083] Keep other parameters in formula (2) unchanged and introduce the variable scale coefficient K , amplify the dynamic measurement signal on the time axis K times. At this time, the angular frequency is numerically ω = K ∈[2π, 6π] rad / s, the dynamic measurement signal becomes as follows:

[0084] (4)

[0085] Where, t st Represents the time axis after scaling.

[0086] From formula (4), we can see that the angular frequency of the drilling tool dynamic measurement signal is amplified on the time axis. K times, that is, the angular frequency ω from K Compressed to 1 rad / s, the signal s( t st ) exists, and then ω = K The angular frequency value of the signal to be measured can be restored based on the relationship between the two.

[0087] However, when processing actual measurement signals, it is not possible to directly scale the frequency of the measured signal through the linear transformation of formula (4). However, the frequency reconstruction of the dynamic measurement signal can be achieved by adjusting the step size of the numerical calculation. Therefore, the variable scaling calculation method is designed as follows:

[0088] 1) Assume that the sampling frequency of the dynamic measurement signal is f s , then the step size of the numerical calculation is T =1 / f s ;

[0089] 2) Substitute the variable scale coefficient and update the numerical calculation step size to T st = K · T = K / f s .

[0090] After the above processing, the original angular frequency is ω , the sampling frequency is f s The dynamic measurement signal of the drilling tool is converted into an angular frequency of ω / K , the sampling frequency is f s / K The reconstructed signal.

[0091] 3) Input the reconstructed signal into the tristable chaotic system and apply the updated step size T st The system is iteratively calculated, and finally the frequency of the dynamic measurement signal is identified according to the change of the system output phase.

[0092] The advantage of this method is that the angular frequency of the signal to be measured is compressed to 1 rad / s through variable-scale calculation. The angular frequency of the driving signal does not change during the entire detection process, so the critical amplitude of the system when a phase change occurs does not change. This solves the problem that the change in the driving signal frequency when applied to the dynamic measurement signal detection of the drilling tool will change the size of the critical amplitude Ac when the system undergoes a phase change, which makes it difficult to apply the frequency detection of the tristable chaotic system. By changing the numerical calculation step size, the angular frequency of the drilling tool measurement signal is compressed to meet the detection conditions of the tristable chaotic system, thus solving the problem that the dynamic response characteristics of the system deteriorate during application, seriously affecting the accuracy and feasibility of frequency detection.

[0093] Full phase frequency detection using array tristable chaotic system:

[0094] In order to solve the influence of initial phase angle on frequency detection, this application proposes a full-phase frequency detection scheme based on array tristable chaotic system. The frequency detection model of tristable chaotic system considering initial phase angle is:

[0095] (5)

[0096] Where, η is the amplitude of the signal to be measured; γ and φ are the initial phase angles of the driving signal and the signal to be measured, respectively. Considering the variable scale processing technology proposed when applying the variable scale tristable chaotic system to detect large frequency signals, the angular frequency of the signal to be measured is directly taken as 1 in formula (5).

[0097] Combining and simplifying the first two terms on the right side of formula (5), we can get

[0098] (6)

[0099] Assumptions P and Q are the two straight sides of a right triangle, R is the hypotenuse and is given by

[0100] (7)

[0101] Assume sin θ = P / R 、cos θ = Q / R , then formula (6) can be further derived as follows (8)

[0102] From the derivation of formula (8), we can see that the sine function has little effect on the phase trajectory of the tristable chaotic system solution, and only affects the initial position of the solution. Therefore, the expression for the amplitude of the above sine function is established as follows:

[0103] (9)

[0104] The right side of formula (9) is the minimum amplitude that causes the output phase of the tristable chaotic system to change. When formula (9) is established, the system output phase changes from chaos to large-scale periodicity. Since the amplitude of the drilling tool measurement signal is usually greater than 0.1 and the minimum is not less than 0.02, the amplitude of the signal to be measured is set to η Set it to 0.02 and substitute it into formula (9) to obtain the following relationship:

[0105] (10)

[0106] Solving formula (10) we can get: φ - γ The range of the change is (-60.85°, 60.85°). Therefore, when the initial phase angle of the driving signal is γ When it is 0, the initial phase angle of the signal to be measured φ The chaotic phase transition can only be applied to complete the frequency detection within the range of [-60°, 60°]. In other words, there is a detectable window for the initial phase angle of the signal to be measured, such as Figure 6 The shaded area in the figure indicates γ 0 o'clock φ detectable range.

[0107] Full coverage of the detection window in the entire range of [-π, π] can be achieved by adjusting the initial phase angle of the driving signal. Specifically, when the initial phase angle of the driving signal γ When it is -120°, φ The detection window is from -180° to -60°; when γ When it is 120°, φ The detection window is 60° to 180°. Therefore, this application expands the typical tristable chaotic system shown in formula (5) into an array tristable chaotic system composed of three different driving equations, as shown in formula (11):

[0108] (11)

[0109] Substituting the drill tool measurement signal into the aforementioned array tristable chaotic system, the presence of the measured signal can be determined only if the output phase of any of the equations changes, thereby determining the measured signal's frequency. Therefore, the implementation of the array tristable chaotic system effectively solves the problem of achieving a change in the system's output phase at any initial phase angle when applying this method, thereby completing the frequency detection of the dynamic measurement signal.

[0110] In order to solve the above three problems at the same time, the technical solution of large frequency signal detection using variable scale tristable chaotic system and the technical solution of full phase frequency detection using array tristable chaotic system are combined and used for the optimization of tristable chaotic system. The solution process is as follows: Figure 7 Shown and summarized below:

[0111] Step 1: Set the initial phase angle of the driving signal to 0 and ±2π / 3 to obtain the array tristable chaotic system, and input the measured signal and noise into the system;

[0112] Step 2: Set appropriate scaling coefficients to reconstruct the angular frequency and sampling frequency of the measured signal, and then solve the array tristable chaotic system with the updated calculation step size;

[0113] Step 3: Adjust the scaling coefficient and observe the output phase trajectory of the array tristable chaotic system. As long as the output phase of one equation changes, the value of the scaling coefficient at this time is the angular frequency of the signal to be measured.

[0114] In one possible embodiment, the x-axis accelerometer measurement signal is used as the experimental object for testing and analysis. First, an array tristable chaotic system is constructed and the collected data is input into the array system; then, the input signal is discretized using a variable scaling coefficient with a sampling frequency of K / fs; finally, the array system is solved by continuously adjusting the variable scaling coefficient and the system output phase trajectory is observed. Figure 8 、 9 , 10, and 11. It can be seen that when the scaling coefficient and the drive signal angular frequency are both appropriate, the array system output phase state transitions to a large-scale periodic state. This shows that the technical solution of this application can effectively identify the frequency value of the dynamic measurement signal of the drilling tool.

[0115] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications that fall within the scope of the present invention and the preferred embodiments.

[0116] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for detecting the frequency of a dynamic measurement signal of a drilling tool, characterized in that: include: Collect dynamic signal data of drilling tools; Performing high-frequency signal detection on the drilling tool dynamic signal data by using a variable-scale tristable chaotic system; Performing full-phase frequency detection of the drilling tool dynamic signal data through an array tristable chaotic system; The variable-scale tristable chaotic system and the array tristable chaotic system are combined to simultaneously detect the dynamic signal data of the drilling tool; The high-frequency signal detection of the drilling tool dynamic signal data by using the variable-scale tristable chaotic system includes: Reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal; Inputting the reconstructed signal into the variable-scale tristable chaotic system for iterative calculation; identifying the frequency of the reconstructed signal according to a change in the output phase of the variable-scale tristable chaotic system; The full-phase frequency detection of the drilling tool dynamic signal data by using the array tristable chaotic system includes: The tristable chaotic system is expanded into an array tristable chaotic system by adjusting the initial phase angle. Substituting the drilling tool dynamic signal data into the array tristable chaotic system to obtain the full phase frequency of the drilling tool dynamic signal data to be measured; The step of combining the variable-scale tristable chaotic system and the array tristable chaotic system to simultaneously detect the dynamic signal data of the drilling tool includes: An array tristable chaotic system is obtained by setting the initial phase angle of the drilling tool dynamic signal data; Inputting the dynamic signal data and noise of the drilling tool to be measured into the array tristable chaotic system; reconstructing the angular frequency and sampling frequency of the dynamic signal data by using a variable scaling coefficient; Solving the array tristable chaotic system through the reconstructed calculation step size; Adjusting the variable scale coefficient to complete the detection of the drilling tool dynamic signal data; The adjusting the variable scale coefficient to complete the detection of the drilling tool dynamic signal data includes: Observing the output phase trajectory of the array tristable chaotic system after adjusting the variable scaling coefficient; The angular frequency of the drilling tool dynamic signal data is determined according to the output phase trajectory and the value of the variable scaling coefficient.

2. A method for detecting the frequency of a dynamic measurement signal of a drilling tool according to claim 1, characterized in that: Reconstructing the drilling tool dynamic signal data to obtain a reconstructed signal includes: Introducing a variable scale coefficient into the drill tool dynamic signal data to restore the angular frequency value of the drill tool dynamic signal data to be measured; The frequency reconstruction of the drilling tool dynamic signal data is achieved by adjusting the step size of the numerical calculation.

3. The method for detecting the frequency of a dynamic measurement signal of a drilling tool according to claim 1, wherein: The method of expanding the tristable chaotic system into an array tristable chaotic system by adjusting the initial phase angle is to divide the initial phase angle into three intervals and substitute them into the expression of the tristable chaotic system to obtain the array tristable chaotic system composed of three different driving equations.

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