Continuous wave mud pulser pressure wave signal generation control method and system

Abstract

The application discloses a continuous wave mud pulse generator pressure wave signal generation control method and system, and belongs to the technical field of oilfield drilling. The method comprises the following steps: S1, a dynamic mathematical model of a continuous wave mud pulse generator is established; S2, a rotor position tracking error is calculated; S3, the rotor position tracking error is constrained based on a specified performance function, and an error conversion function is used to convert the rotor position tracking error, so that the rotor position tracking error is bounded; S4, a finite time disturbance observer is used to estimate unknown disturbances in real time; and S5, a composite controller combining specified performance control and non-singular fast terminal sliding mode control is constructed, and a control input is compensated by using the real-time estimation value of the unknown disturbance. The application can guarantee the generation accuracy of the pressure wave signal from the source end, effectively improve the reliability and quality of downhole data transmission, and improve the performance of the measurement-while-drilling system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oilfield drilling, and particularly relates to a continuous wave mud pulse generator pressure wave signal generation control method and system. BACKGROUND

[0002] Efficient exploration and development of oil and gas resources rely on advanced drilling technology. As the "eyes" of modern oil and gas exploration, measurement-while-drilling technology can transmit key downhole data in real time, guide drilling operations, and improve drilling efficiency and success rate. Among various transmission methods, continuous wave mud pulse transmission technology has become the mainstream solution in the industry due to its high reliability and wide applicability.

[0003] A continuous wave mud pulse generator generates continuous sinusoidal pressure waves in the drilling fluid to encode data through the periodic motion of the rotor and stator, and uses phase modulation to transmit downhole information. The accuracy of the pressure wave signal directly determines the accuracy of information modulation and is the key foundation for ensuring the reliability of the data transmission system.

[0004] However, the harsh downhole environment poses a serious challenge to signal generation. The drilling fluid channel has multipath effects, noise interference, and signal attenuation, which can easily lead to waveform distortion. To ensure that the signal has sufficient fault tolerance during transmission, it is necessary to ensure that the original signal output by the generator has high precision from the source. At the same time, the uncertainty and unknown disturbances brought about by harsh working conditions can affect the rotor motion tracking performance, causing signal deviation. Therefore, the key to achieving high-precision pressure wave signals lies in high-precision control of the rotor position under strong interference.

[0005] The document "Double DOF Strategy for Continuous-Wave Pulse Generator Based on Extended Kalman Filter and Adaptive Linear Active Disturbance Rejection Control" (Yang Ziyu et al. IEEE Transactions on Power Electronics, 2022) addresses the problems of alternating load impact and measurement resolution of continuous wave mud pulse generators, and proposes a double-degree-of-freedom control strategy combining extended Kalman filter (EKF) and adaptive linear active disturbance rejection control (LADRC) to achieve fast dynamic response and strong anti-interference ability. Finally, tests are conducted for different disturbances to verify the high robustness of the method.

[0006] In the document "Improved nonlinear active disturbance rejection control for a continuous-wave pulse generator with cascaded extended state observer" (Deng Shiyang et al. Control Engineering Practice, 2024), to solve the problem of anti-interference of continuous wave mud pulse generator, an enhanced nonlinear active disturbance rejection control (EADRC) integrating cascaded extended state observer (CESO) and enhanced nonlinear state error feedback (NLSEF) is proposed. The rotor motion model considering the hydraulic torque is analyzed to represent the external load impact, and an optimized nonlinear function is designed to improve the slow convergence speed in high error state . The CESO is constructed to achieve timely and accurate disturbance estimation, and the enhanced NLSEF is established to combine current and future system information for effective feedback. This method has the advantages of fast response and strong robustness.

[0007] The above method has made significant progress in dealing with disturbances by improving the observer and controller, but its control target mainly focuses on ensuring the stability and convergence of the system, and the quality of the pressure wave signal is not quantified. Therefore, it is necessary to design a high-precision continuous wave mud pulse generator pressure wave signal generation control method to actively limit the rotor tracking error within an allowable maximum range at the signal source end to improve the precision of the generated pressure wave signal. SUMMARY

[0008] The present application aims to solve the problem of pressure wave signal attenuation and distortion caused by insufficient rotor tracking accuracy of the existing continuous wave mud pulse generator pressure wave signal under the influence of multipath effect and unknown disturbance in the drilling fluid channel, and provides a continuous wave mud pulse generator high-precision pressure wave signal generation control method, which can realize high-precision tracking of the rotor to the modulated signal, enhance the accuracy of the pressure wave signal at the source end, and improve the reliability of uphole data demodulation.

[0009] To achieve the above purpose, the present application provides a continuous wave mud pulse generator pressure wave signal generation control method, comprising the following steps:

[0010] S1, establishing a dynamic mathematical model of the continuous wave mud pulse generator;

[0011] S2, calculating the rotor position tracking error;

[0012] S3, constraining the rotor position tracking error based on a specified performance function, and converting the rotor position tracking error using an error conversion function to make the rotor position tracking error bounded.

[0013] S4, real-time estimation of unknown disturbance by using finite-time disturbance observer;

[0014] S5, constructing a compound controller combining prescribed performance control and non-singular fast terminal sliding mode control, and feeding the angular position and angular velocity of the continuous wave mud pulse generator into the compound controller in negative feedback form, and using the real-time estimation value of unknown disturbance to compensate the control input, so as to obtain the pressure wave waveform of the mud pulse generator.

[0015] Further, in step S1, the dynamic mathematical model of the continuous wave mud pulse generator is established based on the dynamic equation of the permanent magnet synchronous motor, and the dynamic mathematical model of the continuous wave mud pulse generator is as follows:

[0016] (1)

[0017] wherein, , and , , , , and respectively represent the measured values of the angular position and angular velocity of the continuous wave mud pulse generator, , respectively represent the pole pairs, flux linkage, moment of inertia, friction coefficient, stator inductance and stator resistance of the driving motor of the continuous wave mud pulse generator, , axle current, , respectively represent the , axle voltage of the driving motor of the continuous wave mud pulse generator, , respectively represent the reduction ratio and mechanical transmission ratio of the gear reducer; represents the hydraulic torque;

[0018] Let , the angular position and angular velocity model of the continuous wave mud pulse generator in the dynamic mathematical model of the continuous wave mud pulse generator is simplified as follows:

[0019] (2)

[0020] wherein, , , represents a compound disturbance, represents a control input, is the Shaft current reference signal.

[0021] Further, in step S2, the method for calculating the rotor position tracking error comprises:

[0022] Given the rotor position tracking signal as , the continuous wave mud pulse generator rotor position tracking error is:

[0023] (3).

[0024] Further, in step S3, the specified performance function is:

[0025] (4)

[0026] In the formula, represents the initial error boundary, represents the steady-state error boundary, represents the control convergence rate, is the time.

[0027] Further, the method for restricting the rotor position tracking error by the specified performance function comprises:

[0028] The rotor position tracking error satisfies:

[0029] (5)

[0030] In the formula, is the rotor position tracking error boundary design parameter.

[0031] Further, the method for converting the rotor position tracking error by the error conversion function so that the rotor position tracking error is bounded comprises:

[0032] The error conversion function is introduced :

[0033] (6)

[0034] (7)

[0035] In the formula, represents the conversion error; the inverse transformation of (7) is:

[0036] (8)

[0037] The first order derivative of the conversion error is:

[0038] (9)

[0039] wherein, , is the error normalized standard variable, .

[0040] Further, in step S4, in combination with the continuous wave mud pulse generator angle position and angle velocity model in the simplified dynamic mathematical model, the finite time disturbance observer is as follows:

[0041] (10)

[0042] wherein, are respectively the estimated value of is an auxiliary variable, is an observer gain.

[0043] Further, the non-singular fast terminal sliding mode surface in step S5 is as follows:

[0044] (11)

[0045] wherein, is a non-singular fast terminal sliding mode surface design parameter, and satisfies .

[0046] Further, the method for constructing a composite controller combining the prescribed performance control and the non-singular fast terminal sliding mode control comprises:

[0047] According to the sliding mode equivalent theory, the controller is designed as follows:

[0048] (12)

[0049] wherein, is a control input, represents an equivalent controller, represents a switching controller;

[0050] Let and the equivalent controller is obtained in combination with the non-singular fast terminal sliding mode surface as follows:

[0051] (13)

[0052] wherein, , , ;

[0053] The switching control law is designed as follows:

[0054] (14)

[0055] wherein, is a switching controller Design parameters; the controller, the equivalent controller and the switching controller designed by combining the equivalent theory of sliding mode are obtained as a composite controller:

[0056] (15).

[0057] A continuous wave mud pulse generator pressure wave signal generation control system, comprising:

[0058] A dynamic mathematical model acquisition module: used for acquiring the angular position and angular velocity of the continuous wave mud pulse generator, and establishing a dynamic mathematical model of the continuous wave mud pulse generator according to the angular position and angular velocity;

[0059] A rotor position tracking error calculation module: used for calculating the rotor position tracking error;

[0060] A rotor position tracking error limiting module: used for constraining the rotor position tracking error based on a prescribed performance function, and converting the rotor position tracking error by using an error conversion function, so that the rotor position tracking error is bounded;

[0061] An unknown disturbance estimation module: used for estimating the unknown disturbance in real time by using a finite time disturbance observer;

[0062] A control module: used for constructing a composite controller combining prescribed performance control and non-singular fast terminal sliding mode control, and making the angular position and angular velocity of the continuous wave mud pulse generator enter the composite controller in a negative feedback form, and compensating the control input by using the real-time estimation value of the unknown disturbance, so as to obtain the pressure wave waveform of the mud pulse generator.

[0063] Compared with the prior art, the continuous wave mud pulse generator pressure wave signal generation control system has the advantages and positive effects that:

[0064] The application provides a continuous wave mud pulse generator pressure wave signal generation control method and the application.The application considers the problem of insufficient rotor tracking accuracy of the continuous wave mud pulse generator caused by unknown disturbance under complex downhole working conditions, and proposes a composite control strategy combining prescribed performance control, non-singular fast terminal sliding mode and finite time disturbance observer. The rotor tracking error is constrained by the prescribed performance function, effectively improving the accuracy and consistency of the pressure wave generation from the signal source end; further combined with the non-singular fast terminal sliding mode control, the system state is guaranteed to converge rapidly in a limited time; at the same time, the finite time disturbance observer is used to estimate and compensate the unknown disturbance in real time, which significantly enhances the robustness and anti-interference ability of the system. The application controls from the source of signal generation, guarantees the accurate generation of downhole signals, and improves the data transmission quality and reliability from downhole to ground. The application can ensure the generation accuracy of the pressure wave signal from the source end, effectively improve the reliability and quality of the downhole data transmission, and improve the performance of the measurement while drilling system. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 The continuous wave mud pulse generator pressure wave signal generation control method flowchart described in the embodiments of the application is provided.

[0066] Figure 2 The rotor position tracking error is compared.

[0067] Figure 3 The generated pressure wave signal is compared.

[0068] Figure 4 Figure 3 The generated pressure wave signal A is enlarged. DETAILED DESCRIPTION

[0069] In the following, the application will be specifically described through exemplary embodiments. However, it should be understood that the elements, structures and features in one embodiment can also be beneficially combined into other embodiments without further description.

[0070] The application considers the problems of signal attenuation caused by the multipath effect of the drilling fluid channel and unknown disturbance of the continuous wave mud pulse generator, and proposes a rotor high-precision tracking control method.

[0071] Referring to Figure 1 The application provides a continuous wave mud pulse generator pressure wave signal generation control method, and the specific steps are as follows:

[0072] S1, a dynamic mathematical model of the continuous wave mud pulse generator is established.

[0073] Based on the dynamic equation of the permanent magnet synchronous motor, the dynamic mathematical model of the continuous wave mud pulse generator is as follows:

[0074] (1)

[0075] respectively represent the measured values of the continuous wave mud pulse generator angular position and angular velocity, , respectively represent the measured values of the continuous wave mud pulse generator angular position and angular velocity, , , , , and respectively represent the number of pole pairs, flux linkage, moment of inertia, friction coefficient, stator inductance and stator resistance of the continuous wave mud pulse generator driving motor, , respectively represent the number of pole pairs, flux linkage, moment of inertia, friction coefficient, stator inductance and stator resistance of the continuous wave mud pulse generator driving motor, , shaft current, , respectively represent the number of pole pairs, flux linkage, moment of inertia, friction coefficient, stator inductance and stator resistance of the continuous wave mud pulse generator driving motor, , shaft voltage, , respectively represent the reduction ratio and mechanical power transmission ratio of the gear reducer; represents the hydraulic torque.

[0076] For the convenience of subsequent controller design and derivation, let ; the dynamic mathematical model of the continuous wave mud pulse generator angular position and angular velocity in the dynamic mathematical model (1) of the continuous wave mud pulse generator is:

[0077] ; the dynamic mathematical model of the continuous wave mud pulse generator angular position and angular velocity is simplified as: (2)

[0078] wherein, , , represents a composite disturbance, represents a control input, is a reference signal of the continuous wave mud pulse generator driving motor shaft current.

[0079] S2, calculate the rotor position tracking error.

[0080] Given the rotor position tracking signal , the rotor position, i.e. the continuous wave mud pulse generator angular position , the continuous wave mud pulse generator rotor position tracking error can be represented as:

[0081] (3)

[0082] The rotor position tracking error is the difference between the given rotor position tracking signal and the continuous wave mud pulse generator angular position, which facilitates the constraint of the rotor position tracking error.

[0083] S3, the rotor position tracking error is constrained based on the specified performance function, and the rotor position tracking error is converted using the error conversion function, so that the rotor position tracking error is bounded.

[0084] The specified performance function is introduced as follows:

[0085] (4)

[0086] In the formula, represents the initial error boundary, represents the steady-state error boundary, represents the control convergence rate, is the time.

[0087] The specified performance function is related to the initial error boundary, the steady-state error boundary, and the control convergence speed, and the value of the specified performance function eventually equals the steady-state error boundary as the time increases.

[0088] The rotor position tracking error is constrained by the rotor position tracking error boundary design and the specified performance function, so that there is a boundary above and below. The rotor position tracking error needs to satisfy:

[0089] (5)

[0090] In the formula, is the rotor position tracking error boundary design parameter.

[0091] The error conversion function is introduced The specified performance function is associated with the error conversion function and the rotor position tracking error by converting the rotor position tracking error using the error conversion function:

[0092] (6)

[0093] (7)

[0094] In the formula, represents the conversion error. The inverse transformation of the error conversion function (7) can be obtained as:

[0095] (8)

[0096] The first derivative of the conversion error is calculated as:

[0097] (9)

[0098] wherein, wherein is the error normalized standard variable, .

[0099] The performance function is constructed, the rotor tracking error boundary is set, and the error transformation function The error is coordinate-transformed, and the transformed error is bounded, which ensures that the original rotor position tracking error has a specified performance, ensures that the rotor tracking error is within the preset performance boundary during the entire control process, and limits the range of the rotor tracking error at the source.

[0100] S4, the unknown disturbance is estimated in real time by using a finite-time disturbance observer.

[0101] To achieve fast estimation of unknown disturbances, the finite-time disturbance observer is designed as follows by combining the simplified dynamic mathematical model (2) of the continuous wave mud pulse generator angular position and angular velocity model:

[0102] (10)

[0103] wherein, are the estimated values of , is an auxiliary variable, is the observer gain.

[0104] S5, a compound controller combining specified performance control and non-singular fast terminal sliding mode control is constructed, the continuous wave mud pulse generator angular position and angular velocity are fed back in a negative feedback form into the compound controller, the control input is compensated by using the real-time estimated value of the unknown disturbance, and the mud pulse generator pressure wave waveform is obtained.

[0105] To improve the dynamic response speed, the non-singular fast terminal sliding surface is designed as follows by combining (8):

[0106] (11)

[0107] wherein, is a non-singular fast terminal sliding surface design parameter, and satisfies .

[0108] To reduce chattering and improve control accuracy, the controller is designed as follows according to the sliding mode equivalent theory:

[0109] (12)

[0110] wherein, For control input, denotes an equivalent controller, denotes a switching controller.

[0111] Let And the equivalent controller is designed in combination with the nonsingular fast terminal sliding mode surface (11) As follows:

[0112] (13)

[0113] In the formula, , , .

[0114] The switching controller is designed As follows:

[0115] (14)

[0116] In the formula, is the switching controller design parameter.

[0117] The controller (12) designed in combination with the sliding mode equivalent theory, the equivalent controller (13) and the switching controller (14) are designed as:

[0118] (15).

[0119] With a continuous wave mud pulse generator The shaft current reference signal is the input of the compound controller, the angular position and angular velocity of the continuous wave mud pulse generator are in the form of negative feedback into the compound controller, the real-time estimated value of the unknown disturbance estimated by the finite time disturbance observer is used to compensate the control input, and the pressure wave waveform of the mud pulse generator is obtained through the compound controller control.

[0120] The compound controller combines the nonsingular fast terminal sliding mode surface and the prescribed performance function, and the real-time estimated value of the unknown disturbance estimated by the finite time disturbance observer Compensate the control input So as to ensure the accuracy of the pressure wave signal.

[0121] The application also provides a continuous wave mud pulse generator pressure wave signal generation control system, which comprises:

[0122] A dynamic mathematical model acquisition module is used to acquire the angular position and angular velocity of the continuous wave mud pulse generator, and a dynamic mathematical model of the continuous wave mud pulse generator is established according to the angular position and angular velocity;

[0123] A rotor position tracking error calculation module is used to calculate the rotor position tracking error.

[0124] rotor position tracking error limiting module: for constraining rotor position tracking error based on prescribed performance function, converting rotor position tracking error by error conversion function, and making rotor position tracking error bounded;

[0125] unknown disturbance estimation module: for estimating unknown disturbance in real time by using finite time disturbance observer;

[0126] control module: for constructing compound controller combining prescribed performance control and non-singular fast terminal sliding mode control, making continuous wave mud pulse generator angle position and angular velocity enter compound controller in negative feedback form, compensating control input by using real-time estimation value of unknown disturbance, and obtaining mud pulse generator pressure wave waveform.

[0127] The processing method of each module of the control system is the same as that in the previous embodiment, and will not be described here.

[0128] The application proposes a continuous wave mud pulse generator high-precision pressure wave signal generation control method. Firstly, aiming at the multipath effect and signal attenuation characteristics of the drilling fluid channel, a prescribed performance function is constructed, and a rotor tracking error boundary is set to ensure that the rotor tracking error is always wrapped in the preset performance boundary during the entire control process, thereby ensuring the integrity of the generated pressure wave signal from the source and reserving sufficient capacity margin for the drilling fluid channel. Secondly, a non-singular fast terminal sliding surface is designed. Through the design of the controller, the rotor position can quickly and accurately track the expected signal generated by the geological sensor parameter modulation in a limited time, and the tracking error is always ensured not to violate the preset performance boundary. Finally, a finite time disturbance observer is introduced to estimate and compensate the compound disturbance, ensuring that the continuous wave mud pulse generator can generate high-fidelity pressure wave signals under various harsh working conditions.

[0129] In order to illustrate the effectiveness and feasibility of the application, the application will be further described in combination with the continuous wave mud pulse generator system simulation.

[0130] Consider a certain continuous wave mud pulse generator platform, and obtain the system parameters shown in Table 1 in step S1. The control target is to make the continuous wave mud pulse generator rotor accurately track the rotor tracking signal. The rotor tracking signal is obtained by binary phase shift keying modulation, and its specific form is:

[0131] (16)

[0132] In the formula, denotes the carrier frequency, denotes the phase, denotes the number of rotary valve vanes.

[0133] Table 1: Continuous wave mud pulser platform parameters

[0134]

[0135] The running time is set to 5s, and the sinusoidal disturbance is applied at 2s to simulate the effect of hydraulic torque on the continuous wave mud pulser. The specific form of the sinusoidal disturbance is:

[0136] (17)

[0137] In the formula N.m.

[0138] The rotor position tracking error of the continuous wave mud pulser and the generated pressure wave signal are compared. The comparison methods include proportional integral control (PI), traditional sliding mode control (SMC), and non-singular fast terminal sliding mode control (NFTSMC). Figure 2 For rotor position tracking error comparison, it can be seen from the figure that compared with PI, SMC and NFTSMC, the error of the method remains very small throughout the modulation process, and is always within the constraint boundary. At the same time, under the influence of disturbance, the method also realizes high-precision tracking of the rotor position reference signal. Figure 3 And Figure 4 For the generated pressure wave signal comparison, it can be seen from the figure that compared with the comparison method, the generated pressure wave signal of the method is basically consistent with the ideal signal, has better pressure wave signal generation accuracy, and further indicates that the method effectively ensures the integrity of the generated pressure wave signal.

[0139] The above examples are used to explain the present application, but not to limit the present application, any modification and change made to the present application within the spirit and protection scope of the claims of the present application, falls into the protection scope of the present application.

Claims

1. A method for generating and controlling pressure wave signals in a continuous wave mud pulse generator, characterized in that... Includes the following steps: S1. Establish a dynamic mathematical model for the continuous wave mud pulse generator; S2. Calculate the rotor position tracking error; S3. Constrain the rotor position tracking error based on the specified performance function, and use the error transformation function to transform the rotor position tracking error so that the rotor position tracking error is bounded. S4. Use a finite-time disturbance observer to estimate unknown disturbances in real time; S5. Construct a composite controller that combines specified performance control and non-singular fast terminal sliding mode control. Input the angular position and angular velocity of the continuous wave mud pulse generator into the composite controller in the form of negative feedback. Use the real-time estimate of the unknown disturbance to compensate for the control input and obtain the pressure wave waveform of the mud pulse generator. The non-singular fast terminal sliding surface mentioned in step S5 is: In the formula, Design parameters for a non-singular fast terminal sliding surface, and satisfy... ; The method for constructing a composite controller that combines specified performance control and non-singular fast terminal sliding mode control includes: The controller is designed based on the sliding mode equivalent theory as follows: In the formula, To control the input, Indicates the equivalent controller. Indicates switching controllers; make An equivalent controller is obtained by combining a non-singular fast terminal sliding surface. as follows: In the formula, , , ; Design switching control law as follows: In the formula, To switch controllers Design parameters; the composite controller is obtained by combining the sliding mode equivalent theory with the designed controller, equivalent controller, and switching controller: 。 2. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 1, characterized in that, In step S1, the dynamic mathematical model of the continuous wave mud pulse generator is established based on the dynamic equation of the permanent magnet synchronous motor. The dynamic mathematical model of the continuous wave mud pulse generator is as follows: In the formula, , These represent the measured values ​​of the angular position and angular velocity of the continuous wave mud pulse generator, respectively. , , , , and These represent the number of pole pairs, flux linkage, moment of inertia, coefficient of friction, stator inductance, and stator resistance of the drive motor for the continuous wave mud pulse generator, respectively. , These represent the drive motors of the continuous wave mud pulse generator. , shaft current, , These represent the drive motors of the continuous wave mud pulse generator. , shaft voltage, , These represent the reduction ratio and mechanical power transmission ratio of the gear reducer, respectively. Indicates hydraulic torque; make The simplified dynamic mathematical model of the continuous wave mud pulse generator includes the following models for the angular position and angular velocity of the generator: In the formula, , , This indicates a complex disturbance. Indicates control input, For the drive motor of the continuous wave mud pulse generator Shaft current reference signal.

3. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 2, characterized in that, In step S2, the method for calculating the rotor position tracking error includes: Given the rotor position tracking signal The rotor position tracking error of the continuous wave mud pulse generator is: 。 4. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 3, characterized in that, In step S3, the specified performance function is: In the formula, Indicates the initial error boundary. Indicates the steady-state error boundary. This indicates control over the convergence rate. For time.

5. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 4, characterized in that, Methods for constraining rotor position tracking error by specifying performance functions include: The rotor position tracking error satisfies: In the formula, Design parameters for the rotor position tracking error boundary.

6. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 5, characterized in that, Methods for transforming rotor position tracking error using error transformation functions to make the rotor position tracking error bounded include: Introducing an error transformation function : In the formula, Indicates the conversion error; performing an inverse transformation on (7) yields: Calculate conversion error The first derivative is: In the formula, , For error normalization standard variables, .

7. The method for generating and controlling pressure wave signals in a continuous wave mud pulse generator as described in claim 6, characterized in that, In step S4, combining the angular position and angular velocity model of the continuous wave mud pulse generator in the simplified dynamic mathematical model, the finite-time disturbance observer is as follows: In the formula, They are respectively The estimated value, As an auxiliary variable, This is the observer gain.

8. A pressure wave signal generation and control system for a continuous wave mud pulse generator, characterized in that, include: Dynamic mathematical model acquisition module: used to acquire the angular position and angular velocity of the continuous wave mud pulse generator, and to establish a dynamic mathematical model of the continuous wave mud pulse generator based on the angular position and angular velocity; Rotor position tracking error calculation module: used to calculate rotor position tracking error; Rotor position tracking error limiting module: used to constrain the rotor position tracking error based on a specified performance function, and to transform the rotor position tracking error using an error transformation function to make the rotor position tracking error bounded; Unknown disturbance estimation module: used to estimate unknown disturbances in real time using a finite-time disturbance observer; Control module: Used to construct a composite controller that combines specified performance control and non-singular fast terminal sliding mode control. The angular position and angular velocity of the continuous wave mud pulse generator are fed into the composite controller in the form of negative feedback. The control input is compensated by the real-time estimate of the unknown disturbance to obtain the pressure wave waveform of the mud pulse generator. The non-singular fast terminal sliding surface is: In the formula, Design parameters for a non-singular fast terminal sliding surface, and satisfy... ; The method for constructing a composite controller that combines specified performance control and non-singular fast terminal sliding mode control includes: The controller is designed based on the sliding mode equivalent theory as follows: In the formula, To control the input, Indicates the equivalent controller. Indicates switching controllers; make An equivalent controller is obtained by combining a non-singular fast terminal sliding surface. as follows: In the formula, , , ; Design switching control law as follows: In the formula, To switch controllers Design parameters; the composite controller is obtained by combining the sliding mode equivalent theory with the designed controller, equivalent controller, and switching controller: 。

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