Automatic control method and control device for drilling of deep-hole drill jumbo

Abstract

The application relates to the technical field of automatic drilling control, in particular to a deep-hole drill jumbo automatic drilling control method and a control device, the method comprising the following steps: step one, active excitation and reference calibration of drilling system frequency response characteristics; step two, slip trend identification based on multi-feature fusion deviation; step three, selection of impact timing compensation to inhibit bit slip; and step four, adaptive reference update based on a stable drilling period. The application aims to realize active perception and rapid intervention of dynamic instability in the drilling process, effectively inhibit bit slip, and improve blind shaft drilling precision.

Description

Technical Field

[0001] This application relates to the field of automatic drilling control technology, specifically to an automatic drilling control method and control device for a deep hole drilling rig. Background Technology

[0002] Deep-hole drilling rigs are key equipment used in mine construction for blind shaft excavation, and their drilling accuracy directly affects the quality of the connection between upper and lower sections and construction safety. Existing automated control systems typically employ a preset hole layout diagram combined with drill arm kinematics calculations, using hydraulic valve groups to achieve automatic positioning of the drill arm and drilling operations. In conventional roadway construction, this method can already complete automatic drilling at predetermined hole positions.

[0003] However, when excavating blind wells, a special type of working condition, the small cross-section of the well and the large length-to-diameter ratio of the drill rod result in extremely limited adjustment margin for the drill arm. When the drill bit contacts alternating hard and soft or inclined rock surfaces, the dynamic mismatch between the propulsion force and the contact angle can easily cause the drill bit to slip tangentially along the rock surface. Current control systems generally employ an open-loop control strategy based on preset hole positions, focusing only on the positioning accuracy of the drill arm end and lacking real-time perception and adaptive adjustment capabilities for dynamic forces and slippage trends during drilling. This results in the inability to correct slippage in time, ultimately leading to out-of-tolerance hole opening angles or even drill rod bending and jamming. This problem frequently causes abandoned holes, seriously affecting the well breakthrough accuracy and construction safety. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this application provides an automatic drilling control method and control device for a deep hole drilling rig, and the specific technical solution adopted is as follows: In a first aspect, one embodiment of this application provides an automatic drilling control method for a deep-hole drilling rig, the method comprising the following steps: In the initial stage of normal impact rotary drilling, the attenuated vibration waveform characteristics of the drill pipe-rock system are obtained through active pulse excitation, and the passive response signal during normal drilling is recorded. Based on the features extracted from the active and passive signals, a benchmark feature vector is constructed, and the covariance matrix between the feature parameters is calculated. During drilling, the frequency response feature vector at the current moment is extracted in real time. Based on the covariance matrix, the Mahalanobis distance between the frequency response feature vector and the reference feature vector is calculated. A dynamic envelope is constructed using the Mahalanobis distance of the current time period. Combined with the dynamic envelope determination logic, the slippage trend of the contact relationship between the drill bit and the rock surface is identified. The method for constructing the dynamic envelope includes: Obtain the Mahalanobis distance sequence for the current time period, which is composed of multiple consecutive Mahalanobis distances prior to the current time. The exponentially weighted average and exponentially weighted variance of the Mahalanobis distance sequence are calculated using the exponentially weighted moving average algorithm. The exponentially weighted average plus the exponentially weighted variance by a preset multiple is used as the dynamic envelope at the current moment; When a slippage trend is detected, the torsional direction of the tangential acceleration at the drill pipe tail is detected. If a reverse torsional wave is detected, the triggering time of the next impact pulse is adjusted in advance based on the propagation delay of the shock wave in the drill pipe. This adjustment includes: The tangential acceleration signal in the circumferential direction of the drill pipe tail is collected, and the tangential acceleration within the short-time integration window at the current moment is integrated to obtain the torsional angular velocity of the drill pipe tail at the current moment. The propagation delay of the shock wave from the impact mechanism to the drill bit is calculated based on the phase of the transfer function and the impact frequency. If the direction of the torsional angular velocity at the tail of the drill pipe is opposite to the normal drilling direction at the current moment, then the current moment is determined to be the arrival time of the reverse torsional wave. The trigger time of the next impact pulse is adjusted to the current time plus the propagation delay, and then a fine adjustment is subtracted, so that the shock wave arrives at the critical point where the reverse torsional wave affects the drill bit interface.

[0005] Preferably, the damped vibration waveform characteristics include the natural frequency and damping ratio of the damped vibration waveform; the natural frequency is determined by measuring the reciprocal of the vibration period of the damped vibration waveform; the damping ratio is calculated by measuring the logarithmic attenuation rate of the amplitudes of adjacent peaks of the damped vibration waveform.

[0006] Preferably, the method for extracting features from the passive response signal is as follows: The passive response signals include impact pressure fluctuations and drill pipe axial acceleration during normal drilling. Spectral analysis was performed on the impact pressure fluctuations and drill pipe axial acceleration during normal drilling to obtain the amplitude and phase of the transfer function at the impact fundamental frequency.

[0007] Preferably, the baseline feature vector consists of the mean of each feature parameter obtained in the initial stage.

[0008] Preferably, the frequency response feature vector at the current moment is determined by the frequency response feature vector of the time window in which the current moment is located.

[0009] Preferably, the determination logic is as follows: When the Mahalanobis distance is less than or equal to the dynamic envelope, it is determined to be a normal fluctuation; When the Mahalanobis distance is greater than the dynamic envelope and the duration exceeds a set threshold, it is determined that a slippage trend has been formed.

[0010] Preferably, the compensation adjustment further includes: If the direction of the torsional angular velocity at the tail of the drill pipe is the same as the normal drilling direction at the current moment, then the normal impact timing remains unchanged. If the Mahalanobis distance falls back to within the dynamic envelope during the compensation execution period, the normal impact timing will be restored. If the Mahalanobis distance does not fall back to within the dynamic envelope during the compensation execution period, and the compensation execution becomes ineffective after exceeding the set impact cycle, it is determined to be a serious slippage, and the drill string is controlled to retreat quickly.

[0011] Secondly, another embodiment of this application provides an automatic drilling control device for a deep-hole drilling rig, comprising: The rock drilling arm actuator includes a drilling arm body, a propulsion cylinder and a guide seat, wherein the guide seat is located at the front end of the drilling arm to support the guide drill rod; The impact drilling mechanism includes an impact mechanism, an impact proportional valve, a drill rod, and a drill bit. The impact proportional valve is connected to the impact mechanism and is used to regulate the impact pressure and the timing of the impact pulse triggering. The multi-dimensional sensing unit includes a piezoelectric axial acceleration sensor installed at the tail of the drill pipe near the guide seat, a piezoelectric tangential acceleration sensor in the circumferential direction at the tail of the drill pipe, and a high-frequency pressure sensor located in the impact oil circuit, which are used to collect the axial acceleration, tangential acceleration and impact oil circuit pressure at the tail of the drill pipe in real time. The on-board control device is electrically connected to the impact proportional valve, the propulsion cylinder and each sensor, and is used to execute the drilling automatic control method of the deep hole drilling rig described above.

[0012] This application has at least the following beneficial effects: This application addresses the challenges of drill bit slippage and poor drilling accuracy in blind well drilling conditions by proposing an adaptive control method based on multi-feature fusion sensing and wave interference. This application constructs a reference coupling characteristic of system stiffness-damping-energy transfer through active excitation and passive response, uses Mahalanobis distance to quantify feature deviation in real time to identify slippage trends, and adjusts the timing of the impact pulse to make the impact wave interact with the drill pipe's reverse wave, thereby changing the boundary conditions at the drill bit to suppress slippage. Compared to open-loop control that only focuses on positioning accuracy, this application achieves active sensing and rapid intervention of dynamic instability during the drilling process, effectively suppressing drill bit slippage and improving drilling accuracy in blind wells. Attached Figure Description

[0013] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a flowchart illustrating an automatic drilling control method for a deep-hole drilling rig, as provided in one embodiment of this application. Detailed Implementation

[0015] One embodiment of this application provides an automatic drilling control method for a deep-hole drilling rig, for details please refer to [link / reference]. Figure 1 The method includes the following steps: Step 1: Active excitation and benchmark calibration of the frequency response characteristics of the drilling system.

[0016] The automatic drilling control device acquires the response data of the entire drilling system in two ways during the initial stage of normal impact and rotation drilling (in this embodiment, it is set to the first 10 seconds of normal impact and rotation drilling): 1) Active pulse excitation: Every 3 seconds, the control device sends a pulse signal with a width of 20ms and an amplitude of 105% of the normal impact pressure to the impact proportional valve. This pulse causes the drill pipe-rock system (specifically refers to the local subsystem of the interaction between the drill pipe and the rock, focusing on the dynamic behavior from the drill pipe tail to the rock contact surface. Active pulse excitation directly causes this subsystem to generate free decaying vibration. Therefore, the natural frequency, damping ratio and other characteristics extracted from it mainly reflect the stiffness, damping and other mechanical properties of the drill pipe-rock contact interface) to generate free decaying vibration. After the pulse ends, a piezoelectric accelerometer installed at the tail of the drill pipe (near the guide seat) collects the damped vibration waveform of the drill pipe's axial direction at a sampling frequency of 2000Hz. It lasts for 150ms.

[0017] The decaying vibration waveform acquired from each active pulse Two key features can be extracted from this: Natural frequency: The natural frequency of the current system is obtained by directly measuring the vibration period of the damped vibration waveform; Damping ratio: Observe the decay rate of the waveform, measure the ratio of the amplitudes of two adjacent vibration peaks, take the natural logarithm to obtain the logarithmic decay rate, and then calculate the damping ratio according to the relationship between damping ratio and logarithmic decay rate in vibration theory; to improve accuracy, the average value of multiple adjacent peaks can be taken.

[0018] 2) Passive response recording: During the intervals without active pulses, the control device synchronously collects the impact pressure fluctuations during normal drilling. (via high-frequency pressure sensor) and drill pipe axial acceleration ; Spectral analysis (Fast Fourier Transform) of these two sets of signals yields the fundamental impulse frequency. The transfer function at (determined by the current impact frequency) ;in, For acceleration and impact pressure at frequency Cross-power spectral density at , The value represents the self-power spectral density of the impact pressure. It should be noted that the calculation methods for both the cross-power spectral density and the self-power spectral density are well-known techniques and will not be elaborated upon in this application.

[0019] Record the amplitude and phase of the transfer function; the amplitude reflects the system's response sensitivity to impact energy, that is, to what extent an impact of the same magnitude can cause drill pipe vibration; the phase reflects the time lag in the transmission of impact energy from the impact mechanism to the drill pipe measurement point.

[0020] Furthermore, the average values ​​of the characteristic parameters obtained from multiple active pulses and passive analyses during the initial stage of drilling were used to construct the baseline feature vector. This vector contains four components: Simultaneously, it is also necessary to calculate the statistical standard deviation of each feature parameter in the initial stage, as well as the covariance matrix among the four feature parameters (it should be noted that before calculating the covariance matrix, the four feature parameters are standardized first, and then the covariance matrix is ​​calculated, which is equivalent to calculating the correlation coefficient matrix), denoted as . It records the correlation between various characteristic parameters; when the system stiffness decreases, the natural frequency will decrease, while the damping ratio will often increase. This inverse relationship is the correlation between characteristics, which is encoded in the covariance matrix and will be used later to distinguish between normal coupled fluctuations and real abnormal deviations.

[0021] Step 2: Slip trend identification based on multi-feature fusion deviation.

[0022] The control device uses a 150ms time window and a 50ms sliding step to continuously extract the frequency response feature vector of the current time window from the latest acquired data (i.e., there is no active pulse excitation at this time, only passive response recording), and records it as the frequency response feature vector of the current time: It should be noted that the feature vector of the current time window is calculated in the same way as the baseline feature vector. Both are constructed from the signal features extracted within the corresponding time period (there is no active pulse excitation in the time window after the initial stage, only passive response records; the attenuated vibration waveform of the drill pipe axis can still be collected even without active pulse excitation), and the details will not be elaborated further.

[0023] To eliminate the dimensional differences and numerical magnitude discrepancies among the four characteristics—natural frequency, damping ratio, transfer function amplitude, and transfer function phase—and ensure the accuracy of subsequent multi-feature fusion analysis, the frequency response feature vector at the current moment is... The standardization and normalization process based on the baseline features is carried out as follows: The single feature deviation value is calculated using the standardized normalization formula: ;in, The standard deviation of the i-th feature in the initial stage (can be extracted from the diagonal elements of the covariance matrix obtained in step one). Let be the parameter value of the i-th feature in the baseline feature vector. Given the parameter value of the i-th feature in the frequency response feature vector at the current time, obtain the normalized deviation value of the i-th feature at the current time. The four normalized bias values ​​are combined into a 4-dimensional bias vector. Let be the deviation vector at the current time.

[0024] It is worth noting that, in the calculations using the formula in this application, if the denominator is 0, a positive number needs to be added to the denominator. (like (The implementer can also choose a value according to the dimensions) to prevent the denominator from being zero.

[0025] Then, based on the covariance matrix obtained in step one, the Mahalanobis distance between the frequency response eigenvector at the current time and the reference eigenvector is calculated: ;in Represents the deviation vector The transpose of , The inverse matrix representing the covariance matrix. The Mahalanobis distance between the current frequency response eigenvector and the reference eigenvector is calculated by integrating the four features at the current moment into a single comprehensive deviation. This measure indicates the deviation of the current frequency response eigenvector from the reference eigenvector. The degree of accuracy is determined, and the correlation between various features is automatically considered.

[0026] For example, if the natural frequency decreases by 10% while the damping ratio increases by 20% accordingly, this pattern of change matches the correlation recorded in historical data, and the value of this composite index will not increase significantly. However, if the natural frequency decreases while the damping ratio also decreases, this anomalous combination will be amplified by this index, resulting in a sharp increase in the value.

[0027] Next, in order to adapt to the reference drift caused by factors such as slow changes in lithology and gradual wear of drill pipe during drilling, this application adopts a dynamic envelope to replace the fixed threshold. The method for constructing this envelope is: The Mahalanobis distance sequence, composed of multiple consecutive sets of time-series Mahalanobis distances from the current moment and preceding moments (to ensure a balance between stability and operational condition tracking, 30-50 consecutive sets can be selected, with 30 sets preferred in this embodiment), is denoted as the Mahalanobis distance sequence for the current time period. This sequence is a sample set reflecting the recent fluctuation state of the system. This sequence is continuously updated as the drilling progresses, always retaining the latest time-series data and eliminating outdated data from the past, thereby conforming to the slow change characteristics of the operational conditions and avoiding interference from outdated data in determining the current normal fluctuations.

[0028] An exponentially weighted moving average (EWMA, a well-known technique, will not be elaborated further) is applied to the Mahalanobis distance sequence for the current time period. Unlike ordinary arithmetic average, this algorithm assigns higher weights to the most recently acquired Mahalanobis distances and gradually reduces the weights to historical Mahalanobis distances from earlier periods. This not only smooths out instantaneous noise interference but also sensitively tracks the slow drift of system operating conditions. The calculation result is denoted as the exponentially weighted average. It reflects the current normal fluctuation center, that is, the benchmark fluctuation level under no-slip condition.

[0029] Based on the exponential weighting rule, the exponentially weighted variance of the Mahalanobis distance sequence for the current time period is calculated simultaneously, denoted as . To represent the degree of dispersion of the current fluctuation, used to construct an adaptive dynamic envelope: in, The dynamic envelope at the current moment. and The value is a preset scaling factor, mainly used for fine-tuning to adapt to different drilling scenarios and equipment conditions. In this embodiment, the value is 1.0. It can be fine-tuned later according to the compensation effect. The value 3 is a preset multiple used to adjust the dynamic envelope.

[0030] In process control, the upper control limit is usually set as "mean + 3σ". When the observed value exceeds this limit, it is considered that an anomaly requiring attention has occurred in the process. The fluctuation center is then multiplied by three times the fluctuation dispersion to obtain the current envelope value. This envelope is equivalent to an adaptive statistical control limit. Its principle is similar to the exponentially weighted moving average control chart commonly used in industrial process control. It can automatically track the slow changes in system characteristics and always provide a normal fluctuation range that conforms to the current operating conditions.

[0031] Furthermore, this application combines dynamic envelope determination logic to identify the slippage trend of the contact relationship between the drill bit and the rock surface. The specific determination logic is as follows: when If the fluctuation is deemed normal, meaning the system is within the normal fluctuation range, then drilling continues steadily. when Furthermore, if the duration exceeds the set threshold (in this embodiment, it is set to 20ms, meaning that all four consecutive sliding windows exceed this threshold), it is determined that a sliding trend has been formed, and the compensation mechanism is immediately triggered.

[0032] The condition of setting the duration to more than 20 milliseconds is to avoid false triggering caused by transient noise interference. Those skilled in the art can flexibly adjust this time parameter according to the noise level at the site.

[0033] For slip trend identification, traditional single-feature or multiple single-feature judgment conditions have significant limitations. For example, simply looking at the decrease in natural frequency may indicate that the rock is softening or that the drill pipe is slipping; simply looking at the increase in damping ratio may indicate that the friction is increasing or that the cuttings are accumulating. However, this application establishes a coupled relationship between "stiffness-damping-energy transfer" by constructing a benchmark feature vector and uses the covariance matrix to learn the normal fluctuation mode of the system. This means that the system allows the rock to harden or soften, but does not allow abnormal contact between the drill bit and the rock. It has the ability to clearly distinguish between changes in working conditions and failure modes.

[0034] Step 3: Selectively suppress drill bit slippage by compensating for impact timing.

[0035] Existing technologies typically employ amplitude adjustment methods such as increasing impact pressure and decreasing propulsion force after detecting anomalies. However, this approach has limitations: amplitude adjustment requires energy accumulation, has a slow response speed, and sudden changes in energy levels may introduce new disturbances.

[0036] To this end, this application proposes a compensation approach based on phase modulation: without changing the magnitude of the impact energy, the phase modulation of the stress state at the drill bit end is achieved by selecting the timing of the impact energy injection and utilizing the wave propagation delay characteristics in the drill pipe.

[0037] Because the cutting teeth of the drill bit have a specific geometric helix angle, there is a physical coupling relationship between the longitudinal axial force and the tangential torsional force. By finely adjusting the timing of the shock wave's arrival at the drill bit, ensuring it arrives at the critical phase when the drill bit begins to slip, the longitudinal impact can instantly increase the axial normal pressure between the drill bit and the rock surface. According to Coulomb's law of friction, the increase in normal pressure is directly equivalent to increasing the tangential anti-slip frictional resistance, thereby effectively disrupting the periodic development of the slip trend and achieving the purpose of suppressing drill bit slippage.

[0038] Therefore, this application first needs to clarify that when slippage occurs at the drill bit and the rock resistance suddenly drops, the drill pipe will release elastic potential energy, which will generate a characteristic signal - namely, the generation of a reverse torsional wave. Therefore, it is necessary to obtain the current motion state of the drill pipe tail through sensors. An acceleration sensor is placed in the tangential direction at the drill pipe tail to measure the tangential acceleration of the drill pipe surface. By integrating this tangential acceleration signal over a short time, the torsional angular velocity at the tail of the drill pipe can be obtained. in, The value represents the torsional angular velocity of the drill pipe tail at the current moment (unit: rad / s). A positive value indicates that the torsional direction is the same as the normal drilling direction, and a negative value indicates that the direction is opposite. R is the drill pipe radius, which is used to convert tangential acceleration into angular acceleration, and then obtain the angular velocity through integration. The tangential acceleration of the drill pipe surface at The instantaneous value at time t, with an integration window T of 10 ms, where t represents the current time. Let be the integral variable, representing the continuous time from a certain point in the past to the present moment; Indicates from Time's up Integrate the tangential acceleration over this time interval.

[0039] The reason for using short-time integration instead of long-time integration is to avoid integration drift. Direct integration will accumulate the zero-point drift of the sensor, resulting in distorted results. Here, the integration window is set to 10 milliseconds, which is sufficient to capture the main characteristics of the reverse torsional wave.

[0040] Secondly, it is necessary to know how long it takes for the shock wave to propagate from the impact mechanism to the drill bit. This propagation delay can be obtained from the previously calculated phase of the transfer function: divide the phase value of the transfer function by the impact frequency. This multiple gives the propagation delay in seconds. This refers to the time delay of the shock wave propagating from the impact mechanism to the drill bit. This time delay includes the time it takes for the stress wave to propagate along the length of the drill pipe and the reflection delay when passing through each joint. It is an inherent and relatively stable parameter of the system and can be determined through initial calibration.

[0041] With the two key pieces of information mentioned above—the direction of the torsional angular velocity at the tail of the drill pipe at the current moment and the propagation delay of the shock wave—the control device can actively compensate and adjust the triggering timing of the shock pulse, thereby delivering the longitudinal impact force to the drill bit at the critical moment when slippage occurs.

[0042] The core operation of this compensation application is to determine when the next impact pulse should be triggered based on the direction of the torsional angular velocity of the drill pipe tail at the current moment.

[0043] Specifically, let the current time be... The normal impact period is The next shock should have come in The moment is triggered after one impact cycle. The control device first determines the direction of the current torsional angular velocity at the drill pipe tail—calculating the sign of the current torsional angular velocity direction: ; if This indicates that the twisting direction is the same as the normal drilling direction, suggesting that the reverse twisting wave has not yet arrived or has already passed. if This indicates that the direction of the twist is opposite to the normal drilling direction, meaning that the reverse torsional wave is passing through the tail measurement point at this moment.

[0044] if This indicates that the angular velocity is zero, and usually no special treatment is required.

[0045] When a reverse torsional wave is detected ( When this happens, the critical control node can be determined. At this point, the control device will adjust the trigger time of the next impact pulse to: The formula represents the time from the current moment. Plus transmission delay Then subtract a very small adjustment amount. The initial value of this fine-tuning amount can be around 0.3 milliseconds.

[0046] It is important to note that this reverse torsional wave originates at the moment the drill bit slips and propagates through the drill pipe to the current moment. Detected; due to the bidirectional consistency of stress wave propagation in the drill pipe, the propagation time delay This represents both the time it takes for the shock wave to descend and, approximately, the time it takes for the reverse torsional wave to ascend; therefore, the current detection time is still used. Compensation is performed based on the benchmark.

[0047] Those skilled in the art need to understand the physical significance of this adjustment: without adjustment, the shock wave will arrive at the drill bit after the normal triggering time plus the propagation delay. At this time, the drill bit may already be in the middle or late stage of slippage, and the longitudinal impact force will not act on the critical point where slippage occurs. By advancing the triggering time by this fine adjustment, the longitudinal shock wave can arrive at the drill bit precisely at the critical moment when the reverse torque begins to have an unloading effect on the drill bit. When the shock wave arrives at the drill bit, the longitudinal impact force is coupled into an instantaneously increased axial normal pressure through the helix angle of the drill bit cutting teeth, thereby generating additional anti-slip frictional resistance at the interface between the drill bit and the rock, preventing further slippage. This effect is macroscopically manifested as an instantaneous increase in the equivalent torsional stiffness of the drill pipe, making it necessary for the drill bit to overcome a greater elastic restoring force if it wants to continue slippage.

[0048] Furthermore, if the direction of the torsional angular velocity at the tail of the drill pipe at the current moment is the same as the normal drilling direction ( If the reverse torsional wave does not occur, the normal impact timing remains unchanged. This is because there is no reverse torsional wave to intervene at this time, and prematurely triggering it may interfere with the normal drilling process.

[0049] The compensation action is executed continuously for three impact cycles (the compensation execution period is set to three impact cycles in this embodiment). In each cycle, the triggering time is dynamically adjusted according to the latest torsional angular velocity direction. During the compensation execution, the control device continuously monitors changes in the comprehensive indicators. like If the system falls back to within the dynamic envelope within 3 cycles, it indicates that the compensation is effective and the system has returned to normal impact timing. like If the drill string does not fall back to within the dynamic envelope within 3 cycles, it indicates that the compensation is insufficient. The fine adjustment amount Δ is then doubled (but not exceeding 0.8ms), and another 3 cycles are executed. If the increase is still ineffective, it is determined to be a serious slippage. The control device issues a command to make the drill string retract quickly to avoid the drill pipe bending and jamming.

[0050] Traditional control methods typically employ amplitude adjustment when encountering anomalies, such as increasing the impact force or decreasing the propulsion force. This is a static adjustment based on energy magnitude. This application proposes a novel timing adjustment approach that does not change the energy magnitude but only alters the timing of energy injection. By utilizing the inherent force coupling characteristics of the drill bit geometry, the longitudinal impact force can be transformed into the anti-torsional resistance required to suppress slippage at the critical phase of slippage occurrence, thereby disrupting the periodic development of the slippage trend and achieving the goal of suppressing drill bit slippage. This compensation method does not require precise phase alignment or knowledge of the instantaneous motion state of the drill bit; it only needs to determine the direction of torsion and make coarse time delay adjustments. It has low engineering implementation difficulty and can fully guarantee the real-time performance of the control system.

[0051] Step 4: Adaptive baseline update based on stable drilling period.

[0052] After completing a drilling cycle, the control unit needs to review the entire drilling process and filter out all stable drilling periods that did not trigger compensation, that is, those periods where the Mahalanobis distance was always below the dynamic envelope.

[0053] The feature parameters within these stable periods are extracted, their average value is calculated, and then this average value is used to update the baseline feature vector. The update method is recursive averaging. Extract the average values ​​of the feature parameters for these time periods to form a vector. Then, the baseline feature vector is updated using a recursive averaging method: The update formula represents the new baseline feature vector. Through the old benchmark eigenvectors Multiply by a coefficient close to 1, and add the vector extracted during this stable period. Multiply by a very small learning rate. This learning rate is typically between 0.05 and 0.1; in this example, it is 0.05.

[0054] The purpose of this slow update is to allow the benchmark to gradually adapt to the drift in system characteristics caused by factors such as drill pipe wear and long-term slow changes in lithology, while avoiding the impact of a single abnormal data on the benchmark.

[0055] At the same time, the scaling factor of the dynamic envelope needs to be adjusted based on the actual effect of this compensation. and Make fine adjustments; The principles for fine-tuning can be set by those skilled in the art based on their field experience. For example, if there are too many compensation cycles but the drilling deviation is very small, it indicates that the envelope is too sensitive and can be appropriately increased. and If the number of compensation cycles is too low but the drilling deviation exceeds the standard, it indicates that the envelope is too sluggish, and the number of cycles can be appropriately reduced. and Adjust the step size to 0.05 to ensure slow changes.

[0056] The control device ultimately converts all the above analysis results into control signals for the impact proportional valve and the propulsion proportional valve. For the impact valve, a high-speed digital output module is used to precisely control the triggering time of each time. The propulsion valve maintains its current opening during the compensation period and only executes the retraction command when rapid retraction is required.

[0057] It should be noted that all control calculations are independent of the coarse positioning process of the drill arm and do not affect the original control functions.

[0058] Based on the same inventive concept as the above-mentioned automatic drilling control method for deep hole drilling rigs, an embodiment of this application also provides an automatic drilling control device, including a rock drilling arm actuator, an impact drilling mechanism, a multi-dimensional sensing unit, and an on-board control device. The rock drilling arm actuator includes a drilling arm body, a propulsion cylinder and a guide seat, wherein the guide seat is located at the front end of the drilling arm to support the guide drill rod; The impact drilling mechanism includes an impact mechanism, an impact proportional valve, a drill rod, and a drill bit. The impact proportional valve is connected to the impact mechanism and is used to regulate the impact pressure and the timing of the impact pulse triggering. The multi-dimensional sensing unit includes a piezoelectric axial acceleration sensor installed at the tail of the drill pipe near the guide seat, a piezoelectric tangential acceleration sensor in the circumferential direction at the tail of the drill pipe, and a high-frequency pressure sensor in the impact oil circuit, used to collect the axial acceleration, tangential acceleration and impact oil circuit pressure at the tail of the drill pipe in real time. The on-board control device is electrically connected to the impact proportional valve, the propulsion cylinder and each sensor, and is used to execute the above-mentioned automatic drilling control method for the deep hole drilling rig.

[0059] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not invented in this application.

[0060] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. An automatic control method for drilling a deep-hole drilling rig, characterized in that, The method includes the following steps: In the initial stage of normal impact rotary drilling, the attenuated vibration waveform characteristics of the drill pipe-rock system are obtained through active pulse excitation, and the passive response signal during normal drilling is recorded. Based on the features extracted from the active and passive signals, a benchmark feature vector is constructed, and the covariance matrix between the feature parameters is calculated. During drilling, the frequency response feature vector at the current moment is extracted in real time. Based on the covariance matrix, the Mahalanobis distance between the frequency response feature vector and the reference feature vector is calculated. A dynamic envelope is constructed using the Mahalanobis distance of the current time period. Combined with the dynamic envelope determination logic, the slippage trend of the contact relationship between the drill bit and the rock surface is identified. The method for constructing the dynamic envelope includes: Obtain the Mahalanobis distance sequence for the current time period, which is composed of multiple consecutive Mahalanobis distances prior to the current time. The exponentially weighted average and exponentially weighted variance of the Mahalanobis distance sequence are calculated using the exponentially weighted moving average algorithm. The exponentially weighted average plus the exponentially weighted variance by a preset multiple is used as the dynamic envelope at the current moment; When a slippage trend is detected, the torsional direction of the tangential acceleration at the drill pipe tail is detected. If a reverse torsional wave is detected, the triggering time of the next impact pulse is adjusted in advance based on the propagation delay of the shock wave in the drill pipe. This adjustment includes: The tangential acceleration signal in the circumferential direction of the drill pipe tail is collected, and the tangential acceleration within the short-time integration window at the current moment is integrated to obtain the torsional angular velocity of the drill pipe tail at the current moment. The propagation delay of the shock wave from the impact mechanism to the drill bit is calculated based on the phase of the transfer function and the impact frequency. If the direction of the torsional angular velocity at the tail of the drill pipe is opposite to the normal drilling direction at the current moment, then the current moment is determined to be the arrival time of the reverse torsional wave. The trigger time of the next impact pulse is adjusted to the current time plus the propagation delay, and then a fine adjustment is subtracted, so that the shock wave arrives at the critical point where the reverse torsional wave affects the drill bit interface.

2. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The characteristics of the damped vibration waveform include the natural frequency and damping ratio of the damped vibration waveform; the natural frequency is determined by measuring the reciprocal of the vibration period of the damped vibration waveform; the damping ratio is calculated by measuring the logarithmic attenuation rate of the amplitudes of adjacent peaks of the damped vibration waveform.

3. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The method for extracting features from passive response signals is as follows: The passive response signals include impact pressure fluctuations and drill pipe axial acceleration during normal drilling. Spectral analysis was performed on the impact pressure fluctuations and drill pipe axial acceleration during normal drilling to obtain the amplitude and phase of the transfer function at the impact fundamental frequency.

4. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The baseline feature vector consists of the mean of each feature parameter obtained in the initial stage.

5. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The frequency response feature vector at the current moment is determined by the frequency response feature vector of the time window in which the current moment is located.

6. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The determination logic is as follows: When the Mahalanobis distance is less than or equal to the dynamic envelope, it is determined to be a normal fluctuation; When the Mahalanobis distance is greater than the dynamic envelope and the duration exceeds a set threshold, it is determined that a slippage trend has been formed.

7. The automatic drilling control method for a deep-hole drilling rig as described in claim 1, characterized in that, The compensation adjustment also includes: If the direction of the torsional angular velocity at the tail of the drill pipe is the same as the normal drilling direction at the current moment, then the normal impact timing remains unchanged. If the Mahalanobis distance falls back to within the dynamic envelope during the compensation execution period, the normal impact timing will be restored. If the Mahalanobis distance does not fall back to within the dynamic envelope during the compensation execution period, and the compensation execution becomes ineffective after exceeding the set impact cycle, it is determined to be a serious slippage, and the drill string is controlled to retreat quickly.

8. An automatic drilling control device for a deep-hole drilling rig, characterized in that, include: The rock drilling arm actuator includes a drilling arm body, a propulsion cylinder and a guide seat, wherein the guide seat is located at the front end of the drilling arm to support the guide drill rod; The impact drilling mechanism includes an impact mechanism, an impact proportional valve, a drill rod, and a drill bit. The impact proportional valve is connected to the impact mechanism and is used to regulate the impact pressure and the timing of the impact pulse triggering. The multi-dimensional sensing unit includes a piezoelectric axial acceleration sensor installed at the tail of the drill pipe near the guide seat, a piezoelectric tangential acceleration sensor in the circumferential direction at the tail of the drill pipe, and a high-frequency pressure sensor located in the impact oil circuit, which are used to collect the axial acceleration, tangential acceleration and impact oil circuit pressure at the tail of the drill pipe in real time. The on-board control device is electrically connected to the impact proportional valve, the propulsion cylinder and each sensor, and is used to execute the drilling automatic control method of the deep hole drilling rig as described in any one of claims 1-7.

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