Deep hole drilling numerical control correction method and system based on force feedback

Abstract

The application provides a deep hole drilling numerical control correction method and system based on force feedback, and relates to the technical field of numerical control machining, which comprises the following steps: monitoring the vibration amplitude and frequency spectrum characteristics of the drill rod surface, comparing them with the cutting vibration characteristic library, and extracting the chip adhesion signal strength index; fusing the index with the resultant time domain signal to generate a data pair, separating the additional load time domain and pure cutting force time domain sequence by using an interference stripping algorithm; if the additional load time domain sequence exceeds the threshold, issuing a clean signal to discharge the chip; comparing the pure cutting force time domain sequence with the corresponding reference and calculating the force deviation, generating a compensation instruction according to the feed compensation strategy; executing the instruction and continuing to process, feeding back the hole diameter and guide deviation, verifying the correction effect and adjusting the parameters until the machining precision is met, so that the chip accumulation can be accurately identified and the cleaning can be triggered, the real cutting force and the additional interference load can be effectively separated, and the feed parameters can be dynamically compensated, thereby significantly improving the deep hole machining precision and stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical processing numerical control technology, and particularly relates to a deep hole drilling numerical control correction method and system based on force feedback. BACKGROUND

[0002] As a key process in mechanical manufacturing, deep hole drilling is prone to be disturbed by various factors due to its closed processing environment and difficulty in chip removal. During drilling, chips are prone to accumulate between the drill rod and the hole wall, causing additional friction and vibration, and leading to abnormal fluctuations in cutting load. Traditional processing methods lack real-time monitoring capability for chip accumulation, making it difficult to distinguish between real cutting force and additional disturbance load, resulting in deviation in cutting force measurement.

[0003] Due to the inability to accurately obtain the real cutting state, the adjustment of feed parameters lacks reliable basis, and problems such as hole diameter deviation and guide deviation are prone to occur. At the same time, chip cleaning in the prior art relies on manual intervention or fixed period operation, and it is difficult to dynamically trigger according to the actual accumulation situation, resulting in untimely or excessive chip cleaning, which not only affects the processing precision, but also reduces the production efficiency. In addition, the precision verification after processing lacks closed-loop linkage with the front-end processing process, making it difficult to correct errors in real time, ultimately leading to unstable deep hole processing quality, and making it difficult to meet the demand for high-precision manufacturing.

[0004] Therefore, it is necessary to provide a deep hole drilling numerical control correction method and system based on force feedback to solve the above technical problems. SUMMARY

[0005] To solve the above technical problems, the present application provides a deep hole drilling numerical control correction method and system based on force feedback, which is used to solve the problem of lack of dynamic monitoring and real-time correction mechanism in existing deep hole drilling, resulting in insufficient processing precision and poor stability.

[0006] The deep hole drilling numerical control correction method based on force feedback provided by the present application comprises:

[0007] The vibration amplitude and frequency spectrum characteristics of the drill rod surface are monitored by using a micro vibration sensing array, and are compared with a normal cutting vibration characteristic library to extract a chip adhesion signal strength index;

[0008] The chip adhesion signal strength index and the collected resultant time domain signal are fused to generate a vibration-force coupled data pair, and a preset interference stripping algorithm is applied to the vibration-force coupled data pair to separate an additional load time domain sequence and a pure cutting force time domain sequence;

[0009] If the additional load time domain sequence exceeds a predefined threshold, a self-cleaning trigger signal is issued to drive the multi-blade wiper at the tail of the drill rod to work cooperatively with the directional jet cleaning nozzle to discharge the accumulated chips in the deep hole;

[0010] The pure cutting force time-domain sequence is compared with the ideal cutting force reference and the force deviation is calculated. Based on the force deviation, a local feed compensation command is generated according to the preset feed compensation strategy.

[0011] The local feed compensation command is executed and processing continues. The hole diameter deviation and guide deviation after processing are fed back to the force separation module through the online measurement device to verify the correction effect and adjust the peeling and compensation parameter set until the processing accuracy target is achieved.

[0012] Preferably, the step of using a micro vibration sensor array to monitor the vibration amplitude and spectral characteristics of the drill pipe surface, and comparing them with a normal cutting vibration characteristic database to extract the chip adhesion signal intensity index, specifically includes:

[0013] N miniature piezoelectric vibration sensors are arranged at equal intervals along the axial and circumferential directions on the drill pipe shell, and the N miniature piezoelectric vibration sensors are in close contact with the deep hole wall.

[0014] According to the sampling rate U s With a sampling duration T, the output of each miniature piezoelectric vibration sensor is synchronously sampled using a high-speed analog-to-digital converter to generate a vibration time-domain signal matrix O=[O1(t), ..., O i (t), ..., O I [t], where I represents the total number of vibration frequency domain signals in the vibration time domain signal matrix, i represents the index of the vibration frequency domain signal in the vibration time domain signal matrix, t represents the current time, and the collected vibration time domain signal matrix O is stored in a circular buffer to form a C1×C2 dimensional matrix, C2=U s ×T, U s ≥10kHz;

[0015] A bandpass filter is used to remove the time-domain signal O of each vibration. i The low-frequency workpiece vibration and high-frequency noise in (t) are used to calculate the filtered vibration time-domain signal O. i The envelope amplitude A of (t) i =max|O i (t)|, for the filtered vibration time-domain signal O i (t) is subjected to a fast Fourier transform to obtain the amplitude spectrum h. i [k], k=1,…,M, where k represents the spectral line index and M represents the total number of spectral lines in the amplitude spectrum. The current spectrum H is generated by aggregating the spectral lines according to their average values. k ;

[0016] Obtain the normal spectrum from the normal cutting vibration feature library obtained through offline calibration. And calculate the current spectrum H k With the normal spectrum correlation degree of the chip adhesion signal intensity index S;

[0017] If the decrease amplitude of the chip adhesion signal intensity index S exceeds the amplitude threshold value, it is determined that there is accumulated chip in the deep hole, and a chip removal request signal is sent out.

[0018] Preferably, the current frequency spectrum H k The calculation formula of the current frequency spectrum H

[0019]

[0020] In the formula, FFT() represents the fast Fourier transform operation;

[0021] The calculation formula of the chip adhesion signal intensity index S is as follows:

[0022] .

[0023] Preferably, the chip adhesion signal intensity index is fused with the collected resultant force time domain signal to generate a vibration-force coupled data pair, and a preset interference stripping algorithm is applied to the vibration-force coupled data pair to separate out an additional load time domain sequence and a pure cutting force time domain sequence, specifically including:

[0024] The resultant force time domain signal F total (t) is collected by a force sensor at the main shaft end of the drill rod, the low-frequency workpiece vibration and high-frequency noise in the resultant force time domain signal F total (t) are removed by using the band-pass filter, and the filtered resultant force time domain signal F s (t) is cut into equal-length sequences according to the sampling rate U total and the sampling time length T;

[0025] The chip adhesion signal intensity index S is updated to a chip adhesion vibration index S(t) according to the actual vibration sampling period;

[0026] The chip adhesion vibration index S(t) and the resultant force time domain signal F total (t) are time-synchronized and aligned to generate the vibration-force coupled data pair;

[0027] The preset interference stripping algorithm uses a vibration-force coupled model, inputs the vibration-force coupled data pair into the vibration-force coupled model, calculates the additional load time domain sequence F int (t), and then combines the resultant force time domain signal F total (t) to calculate the pure cutting force time domain sequence F cut (t);

[0028] If F cut (t) is a negative value or Fcut (t) beyond the normal cutting force range, F cut (t) is marked as an abnormal value and is limited.

[0029] Preferably, the additional load time-domain sequence F int (t) is calculated as follows:

[0030]

[0031] wherein α represents an additional load proportional factor obtained by offline calibration, β represents a nonlinear correction coefficient obtained by offline fitting, and both α and β are parameters of the vibration-force coupling model;

[0032] The calculation formula of the pure cutting force time-domain sequence F cut (t) is as follows:

[0033] .

[0034] Preferably, the comparison of the pure cutting force time-domain sequence with the ideal cutting force reference and the calculation of the force deviation, the generation of the local feed compensation instruction based on the force deviation according to the preset feed compensation strategy specifically comprises:

[0035] At the current machining position, the pure cutting force time-domain sequence F cut (t) within the cutting duration T w is intercepted, and the time average of the pure cutting force time-domain sequence F cut (t) within the cutting duration T avg , i.e. the average cutting force F ref , is calculated:

[0036]

[0037] wherein represents an integral variable;

[0038] The ideal cutting force reference F avg calibrated offline corresponding to the current machining condition is queried from a process database, and the average cutting force F f is combined to calculate the force deviation ΔF:

[0039]

[0040] According to the preset feed compensation strategy, the force deviation ΔF is mapped to a feed speed adjustment amount ΔV f :

[0041]

[0042] wherein K frepresents the feed speed compensation gain calibrated offline;

[0043] If the feed speed adjustment amount AV f exceeds the maximum adjustment range, the feed speed adjustment amount AV f is limited in amplitude;

[0044] The force deviation AF is converted into a cutting depth adjustment amount AL in a proportional relationship:

[0045] AL = -K d AF

[0046] In the formula, K d represents the cutting depth compensation gain calibrated offline;

[0047] If the cutting depth adjustment amount AL exceeds the machining tolerance range, the cutting depth adjustment amount AL is truncated to the tolerance limit;

[0048] The original feed segment is inserted at the current numerical control trajectory point position, the original feed speed V0 is adjusted to V0+AV f , the local feed speed instruction is generated, and the original cutting depth L0 is adjusted to L0+AL, the cutting depth increment instruction is generated, and the local feed compensation instruction is generated by combining the local feed speed instruction and the cutting depth increment instruction.

[0049] Preferably, the local feed compensation instruction is executed and the machining is continued, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through the online measurement device, the correction effect is verified and the peeling and compensation parameter set is adjusted until the machining precision target is reached, and specifically includes:

[0050] The local feed compensation instruction is received and executed, the hole diameter D meas (t) after machining is measured by the electromagnetic diameter measuring sensor assembled at the outlet of the deep hole, and the drill rod center line offset G meas (t) is measured by the laser triangulation guide sensor installed at the front end of the drill rod, the hole diameter reference D ref and the guide reference G ref are combined, the hole diameter deviation AD(t)=D meas (t)-D ref and the guide deviation AG(t)=G meas (t)-G ref are calculated:

[0051] The maximum absolute deviation E max is calculated based on the hole diameter deviation AD(t) and the guide deviation AG(t), the precision tolerance R tol is obtained, and if E max ≤R tolIf the correction effect is qualified, otherwise the correction effect is unqualified, and the peeling and compensation parameter set needs to be adjusted again, and the peeling and compensation operation is continued in the next round until the machining precision target is reached.

[0052] Preferably, the maximum absolute deviation E max The calculation formula is as follows:

[0053] .

[0054] The deep hole drilling numerical control correction system based on force feedback comprises:

[0055] An index extraction module is configured to monitor the vibration amplitude and frequency spectrum characteristics of the drill pipe surface by using a micro vibration sensing array, and compare the vibration characteristics with a normal cutting vibration characteristic library to extract a chip adhesion signal strength index.

[0056] A sequence separation module is configured to fuse the chip adhesion signal strength index and the collected resultant force time domain signal to generate a vibration-force coupling data pair, and apply a preset interference peeling algorithm to the vibration-force coupling data pair to separate an additional load time domain sequence and a pure cutting force time domain sequence.

[0057] A chip cleaning module is configured to issue a self-cleaning trigger signal to drive a multi-blade scraper at the tail of the drill pipe and a directional jet cleaning nozzle to work cooperatively to discharge the accumulated chips in the deep hole if the additional load time domain sequence exceeds a predefined threshold.

[0058] An instruction generation module is configured to compare the pure cutting force time domain sequence with an ideal cutting force reference, calculate a force deviation, generate a local feed compensation instruction based on the force deviation according to a preset feed compensation strategy, and execute the local feed compensation instruction.

[0059] An effect verification module is configured to execute the local feed compensation instruction and continue machining, feed the hole diameter deviation and the guide deviation after machining to the force separation module through an online measuring device, verify the correction effect, and adjust the peeling and compensation parameter set until the machining precision target is reached.

[0060] Compared with the related art, the deep hole drilling numerical control correction method and system based on force feedback provided by the present application has the following beneficial effects:

[0061] The present application can monitor the vibration amplitude and frequency spectrum characteristics of the drill rod surface by using a miniature vibration sensing array, compare with the normal cutting vibration characteristic library, and extract the chip adhesion signal strength index; the chip adhesion signal strength index is fused with the collected resultant time domain signal to generate vibration-force coupling data pairs, a preset interference stripping algorithm is applied to the vibration-force coupling data pairs, and the attached load time domain sequence and the pure cutting force time domain sequence are separated; if the attached load time domain sequence exceeds the predefined threshold, a self-cleaning trigger signal is issued to drive the multi-blade wiper at the tail of the drill rod to work cooperatively with the directional jet cleaning nozzle to strip and discharge the accumulated chips in the deep hole; the pure cutting force time domain sequence is compared with the ideal cutting force reference to calculate the force deviation, and the local feed compensation instruction is generated based on the force deviation according to the preset feed compensation strategy; the local feed compensation instruction is executed and the machining is continued, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through the online measurement device, the correction effect is verified, and the stripping and compensation parameter set is adjusted until the machining precision target is reached, so that the chip accumulation can be accurately identified and cleaning can be triggered, the real cutting force and the additional interference load can be effectively separated, and the feed parameter can be dynamically compensated, thereby significantly improving the deep hole machining precision and stability.

[0062] The present application effectively solves the precision fluctuation problem in deep hole drilling by constructing a complete dynamic correction system, and the abnormal vibration characteristics caused by chip accumulation can be accurately captured by the vibration sensing array to realize real-time identification of the chip accumulation state and provide a reliable basis for subsequent intervention. The present application separates the load signal by means of the vibration-force coupling model, can eliminate the additional interference caused by chip accumulation, accurately extracts the real cutting force, and lays a foundation for feed parameter adjustment. When the chip accumulation is detected to be out of limit, the self-cleaning device of the present application can be triggered in time to remove the accumulated chips through the cooperative action of the wiper and the jet, avoiding the continuous accumulation of interference. Based on the feed compensation instruction generated by the real cutting force deviation, the present application can dynamically adjust the feed speed and cutting depth, real-time correct the machining trajectory, and reduce the hole diameter and guide error. The closed-loop verification mechanism of the present application continuously optimizes the separation parameters and compensation strategies through online measurement feedback results to ensure that the machining precision is stable and up to standard, and significantly improves the precision consistency and machining efficiency of deep hole drilling. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 The flowchart of the deep hole drilling numerical control correction method based on force feedback of the present application;

[0064] Figure 2 The system block diagram of the deep hole drilling numerical control correction system based on force feedback of the present application. DETAILED DESCRIPTION

[0065] The present application will be further described below in combination with the drawings and embodiments.

[0066] Example one

[0067] As Figure 1 shown, the deep hole drilling numerical control correction method based on force feedback comprises:

[0068] S1, the vibration amplitude and frequency spectrum characteristics of the drill pipe surface are monitored by using a micro vibration sensor array, and compared with a normal cutting vibration characteristic library to extract a chip adhesion signal strength index;

[0069] S2, the chip adhesion signal strength index is fused with the collected resultant force time domain signal to generate a vibration-force coupling data pair, and a preset interference stripping algorithm is applied to the vibration-force coupling data pair to separate out an attached load time domain sequence and a pure cutting force time domain sequence;

[0070] S3, if the attached load time domain sequence exceeds a predefined threshold, a self-cleaning trigger signal is issued to drive the multi-blade wiper at the tail of the drill pipe to work cooperatively with the directional jet cleaning nozzle to discharge the accumulated chips in the deep hole;

[0071] S4, the pure cutting force time domain sequence is compared with an ideal cutting force reference to calculate a force deviation, and a local feed compensation instruction is generated based on the force deviation according to a preset feed compensation strategy;

[0072] S5, the local feed compensation instruction is executed and the machining continues, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through an online measurement device, the correction effect is verified and the stripping and compensation parameter set is adjusted until the machining precision target is reached.

[0073] In actual application, the real-time capture of the vibration state of the drill pipe surface can be completed with the aid of a micro vibration sensor array. These sensors are in close contact with the drill pipe and the hole wall contact surface, and can comprehensively collect vibration amplitude and frequency spectrum characteristics. By comparing and analyzing the collected vibration information with the pre-constructed normal cutting vibration characteristic library, the chip adhesion signal strength index can be accurately extracted. This index can quantitatively reflect the accumulation degree of chips between the drill pipe and the hole wall, providing a reliable basis for subsequent intervention measures and realizing early identification of the chip accumulation state.

[0074] Then, the chip adhesion signal strength index can be fused with the resultant force time domain signal collected by the spindle end force sensor for fusion processing to form a vibration-force coupling data pair. Based on the preset interference stripping algorithm, the coupling data pair is deeply analyzed to separate out two types of key sequences: an attached load time domain sequence caused by chip accumulation and a pure cutting force time domain sequence that truly reflects the cutting state, thereby effectively eliminating the interference load caused by chip accumulation and ensuring that subsequent parameter adjustment is based only on the true cutting force, laying a foundation for accurate compensation.

[0075] When the additional load time sequence exceeds the predefined threshold, the self-cleaning mechanism is immediately started. By issuing a self-cleaning trigger signal, the multi-blade wiper at the tail of the drill rod cooperates with the directional jet cleaning nozzle. The wiper can mechanically peel off the attached chips, and the cleaning nozzle further removes the residual chips through directional jet and discharges them outside the hole, avoiding the intensification of processing interference caused by continuous accumulation of chips, and ensuring the stability of the processing environment.

[0076] For example, through 50 sets of normal processing experiments, the maximum natural fluctuation value of the additional load is measured to be 90N, and the upper limit of the 95% confidence interval is 100N. To exclude interference such as material impurities and slight tool vibration, a 20N safety margin is reserved, so the predefined threshold is set to 120N to accurately identify the load anomaly caused by chip accumulation and ensure that the self-cleaning mechanism is triggered in time and without error. When cutting normally, the additional load time sequence fluctuates slightly, such as {42N, 38N, 45N}; when chips accumulate, the sequence value rises significantly, such as {135N, 148N, 155N}, both of which exceed the predefined threshold of 120N, and the self-cleaning mechanism needs to be started immediately.

[0077] Further, the separated pure cutting force time sequence can be compared with the offline calibrated ideal cutting force reference to accurately calculate the force deviation between them. According to the preset feed compensation strategy, the force deviation is converted into specific local feed compensation instructions, covering dynamic adjustments of feed speed and cutting depth. By real-time correction of the machining trajectory parameters, the hole diameter deviation and guide deviation caused by cutting force fluctuation can be effectively offset, and the machining precision can be improved.

[0078] Finally, the feed compensation instructions can be executed and the machining can continue, while the hole diameter deviation and guide deviation data after machining are collected in real time through the online measurement device, and fed back to the force separation module. According to the feedback result, the correction effect is verified, if the deviation does not meet the accuracy requirement, the disturbance stripping parameters and compensation parameters set are dynamically adjusted, and the above correction process is repeated. Through continuous iteration and optimization, the machining precision reaches the preset target, forming a complete dynamic correction closed loop, ensuring the high precision and stability of deep hole machining.

[0079] In the specific implementation process, the vibration amplitude and frequency spectrum characteristics of the drill rod surface are monitored by using a micro vibration sensing array, and compared with the normal cutting vibration characteristic library to extract the chip attachment signal strength index, which specifically includes:

[0080] N micro piezoelectric vibration sensors are arranged equidistantly along the axial and circumferential directions of the drill rod shell, and the N micro piezoelectric vibration sensors are in close contact with the deep hole wall contact surface;

[0081] According to the sampling rate U sWith a sampling duration T, the output of each miniature piezoelectric vibration sensor is synchronously sampled using a high-speed analog-to-digital converter to generate a vibration time-domain signal matrix O=[O1(t), ..., O i (t), ..., O I [(t)], where I represents the total number of vibration frequency domain signals in the vibration time domain signal matrix, i represents the index of the vibration frequency domain signal in the vibration time domain signal matrix, t represents the current time, F s The kHz value is ≥10, and the acquired vibration time-domain signal matrix O is stored in a circular buffer to form a C1×C2 dimensional matrix, where C2=F. s ×T;

[0082] A bandpass filter is used to remove the time-domain signal O of each vibration. i The low-frequency workpiece vibration and high-frequency noise in (t) are used to calculate the filtered vibration time-domain signal O. i The envelope amplitude A of (t) i =max|O i (t)|, for the filtered vibration time-domain signal O i (t) Perform a fast Fourier transform to obtain the amplitude spectrum h i [k], k=1,…,M, where k represents the spectral line index and M represents the total number of spectral lines in the amplitude spectrum. The current spectrum H is generated by aggregating the spectral lines according to their average values. k ;

[0083] Obtain the normal spectrum from the normal cutting vibration feature library obtained through offline calibration. And calculate the current spectrum H k With the normal spectrum The correlation, i.e., the chip adhesion signal intensity index S;

[0084] If the decrease in the chip adhesion signal intensity index S exceeds the amplitude threshold, it is determined that there are accumulated chips in the deep hole, and a chip removal request signal is issued.

[0085] The current spectrum H k The calculation formula is as follows:

[0086]

[0087] In the formula, FFT() represents the Fast Fourier Transform operation;

[0088] The formula for calculating the chip adhesion signal intensity index S is as follows:

[0089] .

[0090] It can be understood that the micro piezoelectric vibration sensors can be first arranged at equal intervals along the axial and circumferential directions of the drill rod shell, and all the sensors need to be closely attached to the contact surface of the deep hole wall. This arrangement can ensure that the sensors can comprehensively capture the local vibration response caused by the behaviors of drill rod and hole wall friction, chip extrusion, etc., provide multi-dimensional original vibration information for subsequent signal analysis, and guarantee the spatial coverage and signal authenticity of monitoring.

[0091] Then, based on the preset sampling parameters, the output signals of the micro piezoelectric vibration sensors are synchronously collected by a high-speed analog-to-digital conversion device. During the collection process, a stable sampling frequency and a continuous time length need to be maintained, the acquired multi-channel continuous vibration time domain signals are integrated into a matrix form, and stored in a ring buffer area. The buffer area has dynamic updating capability, can real-time retain the latest vibration signal data, and provides continuous and complete original information support for subsequent processing, ensuring the timeliness and continuity of signal analysis.

[0092] Further, a band-pass filtering technique can be used to purify the vibration time domain signals, filter out low-frequency workpiece overall vibration interference and high-frequency electromagnetic noise, and improve the signal-to-noise ratio of the signals. Then, the envelope amplitude of the filtered signals is calculated, which can quantitatively reflect the intensity of the vibration impact; at the same time, the filtered signals are subjected to fast Fourier transform, the time domain signals are converted into frequency domain amplitude spectrum, and the frequency spectrum characteristics under the current machining state are generated through spectral line average aggregation, so as to realize the extraction of time domain and frequency domain multi-dimensional characteristics from the vibration signals, and lay a quantitative foundation for the recognition of chip accumulation state.

[0093] In addition, the normal cutting vibration feature library previously constructed through offline calibration can be called to extract the corresponding normal spectrum features. The normal cutting vibration feature library needs to be completed through offline calibration, that is, in the stable machining state without chip accumulation, the baseline test is carried out for the specific materials and tools used for machining, because the cutting vibration characteristics of different materials and tools are different. And the calibration environment needs to be consistent with the real-time machining environment, including using the same machine tool, cutting parameters, cooling conditions, etc., to eliminate the interference of environmental factors on the vibration signals. The normal spectrum feature refers to the vibration spectrum feature in stable cutting, which is obtained through repeated tests and can reflect the vibration state without chip accumulation. Its spectrum form, main frequency component, etc. are obviously different from the abnormal vibration when the chip accumulates, and can be used as a benchmark to judge whether the cutting state is normal.

[0094] By calculating the correlation between the spectrum under the current machining state and the normal spectrum, this correlation is defined as the chip adhesion signal intensity index. This index essentially reflects the degree of agreement between the current vibration characteristics and the normal cutting state. Its value change can intuitively reflect the degree of interference of chip accumulation on vibration characteristics. That is, the more severe the chip accumulation, the more significant the deviation between the current spectrum and the normal spectrum, and the more obvious the decrease in the index value.

[0095] If the decrease in this indicator exceeds the preset amplitude threshold, it indicates that the current vibration characteristics have significantly deviated from the normal cutting state. Based on this, it can be determined that there is chip accumulation inside the deep hole, and a chip removal request signal is issued. This provides a decision basis for the subsequent activation of the self-cleaning device, ensuring that the chip accumulation problem can be detected and dealt with in a timely manner, thereby maintaining the stability of the deep hole drilling process.

[0096] For example, through offline calibration experiments, under stable machining conditions without chip accumulation, the fluctuation range of the chip adhesion signal intensity index of 50 sets of normal data was statistically analyzed, and the maximum natural fluctuation amplitude did not exceed 15%. To avoid false triggering by normal fluctuations, a 5% safety margin was reserved, so the amplitude threshold was set to 20%. This threshold can cover normal interference such as slight differences in material hardness and minor tool wear, and chip removal is only triggered when chip accumulation causes a significant deviation in vibration characteristics. During normal cutting, the chip adhesion signal intensity index is stable between 0.85 and 0.95. If the current chip adhesion signal intensity index drops sharply from 0.9 to 0.65, the decrease is approximately 27.8%, which is significantly greater than the amplitude threshold of 20%, indicating that the current vibration characteristics have significantly deviated from the normal cutting state.

[0097] The above methods enable real-time and accurate identification of chip accumulation, providing crucial pre-monitoring support for dynamic correction in deep hole drilling.

[0098] The process of fusing the chip adhesion signal intensity index with the acquired resultant force time-domain signal to generate a vibration-force coupled data pair, and applying a preset interference stripping algorithm to the vibration-force coupled data pair to separate the additional load time-domain sequence and the pure cutting force time-domain sequence, specifically includes:

[0099] The resultant force time-domain signal F is acquired by a force sensor at the drill pipe spindle end. total (t), the bandpass filter is used to remove the resultant force time-domain signal F. total The low-frequency workpiece vibration and high-frequency noise in (t) are determined according to the sampling rate U. s The time-domain signal F of the resultant force after filtering will be obtained from the sampling duration T. total (t) is cut into equal-length sequences;

[0100] The chip adhesion signal intensity index S is updated to the chip adhesion vibration index S(t) according to the actual vibration sampling period;

[0101] synchronizing the chip adhesion vibration index S(t) with the resultant force time-domain signal F total (t) in time to generate the vibration-force coupling data pair;

[0102] The preset interference stripping algorithm adopts a vibration-force coupling model, inputs the vibration-force coupling data pair into the vibration-force coupling model, calculates the additional load time-domain sequence F int (t), and combines the resultant force time-domain signal F total (t) to calculate the pure cutting force time-domain sequence F cut (t).

[0103] If F cut (t) is negative or F cut (t) exceeds the normal cutting force range, F cut (t) is marked as an abnormal value and is subjected to amplitude limiting processing.

[0104] The calculation formula of the additional load time-domain sequence F int (t) is as follows:

[0105]

[0106] In the formula, α represents an additional load proportional factor obtained through offline calibration, β represents a nonlinear correction coefficient obtained through offline fitting, and α and β are both parameters of the vibration-force coupling model;

[0107] The calculation formula of the pure cutting force time-domain sequence F cut (t) is as follows:

[0108] .

[0109] Firstly, the resultant force time-domain signal can be obtained through the force sensor deployed at the main shaft end of the drill rod, which contains all the force action information in the cutting process and needs to be subjected to band-pass filtering processing to filter out the low-frequency workpiece overall vibration interference and high-frequency electromagnetic noise, so as to ensure the signal purity. Subsequently, the filtered resultant force time-domain signal is segmented into equal-length sequences according to the same sampling frequency and time length as the vibration signal, so that the force signal is matched with the vibration signal in the time scale, laying a foundation for subsequent fusion analysis.

[0110] Then, the extracted chip adhesion signal intensity index can be updated in real time according to the sampling period of the actual vibration signal, and converted into a chip adhesion vibration index that changes continuously with time. This conversion enables the originally static intensity index to have dynamic characteristics, which can reflect the chip accumulation state at different times in real time, making it possible to correlate and analyze the dynamic force signal.

[0111] Subsequently, the dynamicized chip adhesion vibration index can be accurately matched with the preprocessed resultant force time domain signal in the time dimension through the timestamp calibration technology, ensuring that the vibration state index and the force signal at the same time form a one-to-one vibration-force coupling data pair. This strict synchronization in time can effectively avoid the correlation deviation caused by signal delay or misplacement, ensuring the reliability of subsequent model analysis.

[0112] It should be noted that the core of the preset interference stripping algorithm is the application of the vibration-force coupling model. After inputting the vibration-force coupling data pair into the vibration-force coupling model, the model can be constructed based on the offline calibrated physical correlation rule, and the adhesion load time series caused by chip accumulation can be separated through quantitative calculation. This kind of adhesion load belongs to the interference component and is not the force required for real cutting. Combined with the original resultant force time domain signal, the pure cutting force time domain sequence reflecting the real cutting state can be obtained through force component decomposition, realizing the accurate stripping of interference and effective signal.

[0113] Among them, the offline calibration of the vibration-force coupling model needs to be carried out in a stable machining environment to ensure consistency with the actual machining conditions, including the same machine tool, material, tool and cutting parameters, and to avoid environmental interference. Under the conditions of no chip accumulation and different chip accumulation degrees, the vibration signals of the vibration sensor array and the resultant force signals at the spindle end are synchronously collected. After preprocessing the collected vibration-force data and removing noise, the correlation between vibration characteristics and adhesion load is analyzed. Through repeated experiments, the vibration-force coupling model parameters reflecting the relationship between the two are fitted, and the parameter accuracy is verified to ensure that the vibration-force coupling model can accurately quantify the mapping relationship between vibration and adhesion load, and finally determine the stable model parameters to provide a basis for separating adhesion load and pure cutting force online.

[0114] If the separated pure cutting force time domain sequence appears negative value, or its value exceeds the normal cutting force range pre-marked, it is determined as an abnormal value. At this time, the abnormal value needs to be limited in amplitude to avoid the influence of abnormal data caused by sensor error, model calculation deviation, etc. on the generation of subsequent feed compensation instructions, and to ensure the robustness of the entire correction system.

[0115] Therefore, the above process successfully eliminates the interference load caused by chip accumulation through deep fusion of multiple signals and model analysis, providing accurate data support for subsequent parameter compensation based on real cutting force.

[0116] The pure cutting force time domain sequence is compared with the ideal cutting force reference, and a force deviation is calculated. According to a preset feed compensation strategy, a local feed compensation instruction is generated based on the force deviation, specifically including:

[0117] At the current machining position, the cutting duration Tw the pure cutting force time-domain sequence F cut (t), calculate the cutting duration T w the pure cutting force time-domain sequence F cut the time average of F avg :

[0118]

[0119] wherein, denotes the integral variable;

[0120] query the ideal cutting force reference F ref from the process database corresponding to the offline calibration of the current machining condition, combined with the average cutting force F avg , calculate the force deviation ΔF:

[0121]

[0122] According to the preset feed compensation strategy, the force deviation ΔF is mapped to the feed speed adjustment amount ΔV f :

[0123]

[0124] wherein, K f represents the offline calibrated feed speed compensation gain;

[0125] If the feed speed adjustment amount ΔV f exceeds the maximum adjustment range, the feed speed adjustment amount ΔV f is limited in amplitude;

[0126] According to the proportional relationship, the force deviation ΔF is converted into the cutting depth adjustment amount ΔL:

[0127] ΔL=-K d ΔF

[0128] wherein, K d represents the offline calibrated cutting depth compensation gain;

[0129] If the cutting depth adjustment amount ΔL exceeds the machining tolerance range, the cutting depth adjustment amount ΔL is truncated to the tolerance limit;

[0130] Insert the original feed segment at the current numerical control trajectory point position, adjust the original feed speed V0 to V0+ΔV f , generate a local feed speed instruction, and adjust the original cutting depth L0 to L0+ΔL, generate a cutting depth increment instruction, and combine the local feed speed instruction and the cutting depth increment instruction to generate the local feed compensation instruction.

[0131] In practical applications, for the current machining position, the pure cutting force time domain sequence within the set cutting duration is intercepted. By averaging the pure cutting force signal in this time period in the time dimension, the average cutting force reflecting the overall cutting state of the machining section is obtained. This average value can smooth the instantaneous force fluctuation interference, objectively characterize the force level of the current cutting process, and provide a stable quantitative basis for subsequent deviation analysis, avoiding misjudgment caused by instantaneous signal mutation.

[0132] Then, the ideal cutting force reference matching the current machining condition, such as material properties, hole diameter specifications, etc., can be retrieved from the process database. The ideal cutting force reference is obtained through offline calibration, and the offline calibration process needs to be carried out in a stable machining environment without chip accumulation. Specifically, first, the specific machining condition is determined, including the material to be machined, the type and specification of the tool used, and the preset hole diameter, etc. Secondly, under the same machine tool and cooling conditions, the cutting operation is performed according to the standard machining parameters to ensure that there is no additional interference during the process. Finally, the cutting force data is continuously collected by the force sensor, and after removing abnormal fluctuation values, the cutting force characteristics in the stable stage are statistically analyzed. After repeated experiments, the cutting force range that can achieve high-precision machining is extracted as the reference and stored in the process database to form the ideal cutting force reference matching the current condition. The extracted average cutting force is compared with the ideal cutting force reference, and the difference between the two is the force deviation, which directly reflects the deviation degree of the current cutting state from the ideal state and is the core index for triggering compensation adjustment.

[0133] Based on the preset feed compensation strategy, the force deviation is first mapped to the feed speed adjustment amount. This mapping process relies on the feed speed compensation gain obtained through offline calibration, which quantifies the correlation between force deviation and feed speed adjustment, ensuring that the adjustment amount is adapted to the deviation degree. If the calculated feed speed adjustment amount exceeds the preset maximum adjustment range, it needs to be limited to the safety interval allowed by the process to avoid causing cutting stability problems due to excessive adjustment.

[0134] At the same time, the force deviation can be converted into the cutting depth adjustment amount according to the proportional relationship. Through the cutting depth compensation gain obtained through offline calibration, a quantitative correlation between force deviation and cutting depth correction is established to achieve precise control of the cutting section size. If the adjustment amount exceeds the machining tolerance range, it needs to be truncated to the upper or lower limit of the tolerance to ensure that the correction amplitude does not exceed the allowed error range of the part precision requirement, ensuring the compliance of the machining size.

[0135] Finally, the adjusted feed segment can be inserted at the current numerical control trajectory point position, the original feed speed is superimposed with the feed speed adjustment amount, the local feed speed instruction is generated, and the original cutting depth is superimposed with the cutting depth adjustment amount, and the cutting depth increment instruction is generated. By summarizing these two types of instructions, a complete local feed compensation instruction can be formed. Next, the instruction can be directly issued to the actuator to dynamically correct the current machining segment feed parameters, so that the cutting process can be timely adjusted from the deviation from the ideal state, and finally the precision consistency of deep hole machining can be ensured.

[0136] Through accurate quantification of force deviation and dynamic adaptation of parameters, a closed-loop link from cutting state perception to execution correction is constructed, and adaptive regulation of the deep hole drilling process is realized.

[0137] The execution of the local feed compensation instruction and the continuation of the machining process, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through the online measurement device, the correction effect is verified and the peeling and compensation parameter set is adjusted until the machining precision target is reached, specifically including:

[0138] Receiving and executing the local feed compensation instruction, measuring the processed deep hole diameter D meas (t) through the electromagnetic diameter measuring sensor assembled at the deep hole outlet, and measuring the drill rod center line offset G meas (t) through the laser triangulation guide sensor installed at the front end of the drill rod, combining the diameter reference D ref and the guide reference G ref , calculating the hole diameter deviation ΔD(t)= D meas (t)- D ref and the guide deviation ΔG(t)= G meas (t)- G ref :

[0139] Based on the hole diameter deviation ΔD(t) and the guide deviation ΔG(t), the maximum absolute deviation E max is calculated, the precision tolerance R tol is obtained, if E max ≤R tol , the correction effect is qualified, otherwise the correction effect is unqualified, the peeling and compensation parameter set needs to be adjusted again, and the next round of peeling and compensation operation is continued until the machining precision target is reached.

[0140] The calculation formula of the maximum absolute deviation E max is as follows:

[0141] .

[0142] Firstly, the local feed compensation instruction can be received and executed to drive the actuator to continue the deep hole machining process according to the adjusted feed speed and cutting depth, so that the theoretical parameter compensation can be converted into the correction of the actual machining trajectory through the precise regulation of mechanical action, and the entity machining result is provided for subsequent effect verification.

[0143] Then, the real-time monitoring of the machining quality can be realized by relying on high-precision sensing devices. Specifically, the electromagnetic diameter measuring sensor installed at the outlet of the deep hole can non-contact measure the actual hole diameter after machining, capturing the subtle changes in the hole diameter size; the laser triangulation guide sensor installed at the front end of the drill rod is used to monitor the spatial offset of the drill rod center line, reflecting the straightness deviation of the machining trajectory. The two types of sensors work together to obtain machining result data from two dimensions of size accuracy and geometric position accuracy, providing direct basis for deviation calculation.

[0144] Further, the preset hole diameter reference and guide reference can be called from the process standard, the actual measured hole diameter value is subtracted from the hole diameter reference to obtain the hole diameter deviation representing the size deviation; the actual measured center line offset is subtracted from the guide reference to obtain the guide deviation representing the trajectory deviation. These two types of deviations quantify the deviation degree of the current machining result from the ideal state, which are the core indicators for evaluating the correction effect.

[0145] It should be noted that the maximum absolute deviation can comprehensively consider the absolute values of the hole diameter deviation and the guide deviation, and take the maximum value as the overall deviation evaluation index, which comprehensively reflects the most unfavorable state of the machining accuracy. Then, the index can be compared with the preset precision tolerance, which is the allowed maximum deviation range. If the maximum absolute deviation is within the precision tolerance, it is determined that the current correction effect is qualified, and the machining accuracy reaches the expected target; if it exceeds the precision tolerance, it is determined that the correction effect is unqualified, and the parameter adjustment mechanism needs to be started.

[0146] Specifically, the parameter adjustment algorithm can be called to recalibrate the stripping and compensation parameter set. Among them, the stripping parameter refers to the core parameter for separating the additional load and the pure cutting force, mainly including the additional load proportion factor a in the vibration-force coupling model and the nonlinear correction coefficient β. Among them, a is the offline calibrated additional load proportion factor, the value range is [0.1, 0.5]; β is the nonlinear correction coefficient obtained by offline fitting, which is used to optimize the nonlinear mapping relationship between vibration and additional load. The compensation parameter refers to the feed speed compensation gain K f and the cutting depth compensation gain K d , the value range of K f is [0.01-0.01], and the unit is millimeter / Newton*second, the value range of K d is [0.001-0.01], and the unit is millimeter / Newton. When the verification fails, that is, the maximum absolute deviation Emax Exceeding the accuracy tolerance R tol When the specific adjustment logic is as follows:

[0147] For the separation parameters, if the pure cutting force is abnormal, increasing a can enhance the separation degree of the cutting chip interference; if the separation nonlinear deviation is large, the b is corrected to optimize the mapping relationship between vibration and additional load, and to reduce the separation error;

[0148] For the compensation parameters, if the hole diameter deviation is large, K d is increased to increase the cutting depth correction amplitude; if the guide deviation is large, K f is increased to correct the feed direction path deviation and reduce the guide deviation.

[0149] By iteratively adjusting the parameter set, the separation and compensation process is re-executed until Emax≤Rtol. The separation parameters directly affect the separation accuracy of the additional load and the pure cutting force, and if the separation is not accurate, the feed compensation will lose reliable basis; the compensation parameters determine the mapping relationship of the force deviation to the feed speed and the cutting depth adjustment amount, and the parameter mismatch will make the correction measures unable to accurately offset the deviation. By adjusting these two types of parameters, the accuracy of load separation and the adaptability of feed compensation can be optimized.

[0150] After the parameter adjustment, a new round of iterative verification process needs to be entered. First, the adjusted separation and compensation parameter set can be applied to the next round of machining, the local feed compensation instruction is re-executed, the new hole diameter deviation and guide deviation are collected through the online measurement device, the maximum absolute deviation is calculated again and compared with the accuracy tolerance. This process is repeated until the maximum absolute deviation is controlled within the accuracy tolerance range, and the machining accuracy reaches the preset target. This continuous iterative optimization method can dynamically adapt to complex variables in the machining process, such as material hardness fluctuations and cutting chip accumulation characteristics changes, ensuring that the correction strategy always matches the actual machining state.

[0151] Through the above method, the machining deviation can be continuously eliminated, ensuring that the deep hole drilling accuracy gradually converges to the qualified range from the deviation state, and ensuring the stability of the deep hole machining quality.

[0152] Embodiment two

[0153] As shown in Figure 2 , the deep hole drilling numerical control correction system based on force feedback, the system comprises:

[0154] An index extraction module is used to monitor the vibration amplitude and frequency spectrum characteristics of the drill pipe surface by using a micro vibration sensor array, and compare with the normal cutting vibration characteristic library to extract the cutting chip adhesion signal strength index;

[0155] a sequence separation module for fusing the chip adhesion signal intensity index with the collected resultant time-domain signal to generate a vibration-force coupled data pair, and applying a preset interference stripping algorithm to the vibration-force coupled data pair to separate out an attached load time-domain sequence and a pure cutting force time-domain sequence;

[0156] a chip cleaning module for issuing a self-cleaning trigger signal to drive the multi-blade scraper at the tail of the drill rod to work in conjunction with the directional jet cleaning nozzle to strip and discharge the accumulated chips in the deep hole if the attached load time-domain sequence exceeds a predefined threshold;

[0157] an instruction generation module for comparing the pure cutting force time-domain sequence with an ideal cutting force reference and calculating a force deviation, and generating a local feed compensation instruction based on the force deviation according to a preset feed compensation strategy;

[0158] an effect verification module for executing the local feed compensation instruction and continuing machining, feeding the hole diameter deviation and the guide deviation after machining to the force separation module through an online measurement device, verifying the correction effect and adjusting the stripping and compensation parameter set until the machining precision target is reached.

[0159] The index extraction module adopts a micro vibration sensing array fixed on the surface of the drill rod by magnetic attraction, with a sampling frequency of 2 kHz, for monitoring the vibration amplitude and spectral characteristics and comparing them with the normal cutting vibration characteristic library to extract the chip adhesion signal intensity index. The sequence separation module is equipped with a PLC with a preset interference stripping algorithm, which receives vibration and force signals through an EtherCAT bus, fuses to generate a vibration-force coupled data pair, and separates the attached load and pure cutting force time-domain sequences. The chip cleaning module includes a high-speed steel multi-blade scraper, which is keyed to the tail of the drill rod, and a brass directional jet cleaning nozzle, which is threaded to the rear of the scraper, with a jet pressure of 0.6-0.8 MPa and controlled by a solenoid valve. The instruction generation module is based on the Siemens 828D numerical control system and generates a local feed compensation instruction according to a preset feed compensation strategy. The effect verification module is equipped with a laser diameter gauge, which feeds the online measured hole diameter and guide deviation to the sequence separation module through an RS485 interface, and adjusts the stripping and compensation parameter set in a closed loop until the target is reached.

[0160] Through the introduction of the above embodiments, the deep hole drilling numerical control correction method and system based on force feedback can monitor the vibration amplitude and frequency spectrum characteristics of the drill rod surface by using a micro vibration sensing array, compare them with the normal cutting vibration characteristic library, and extract the chip adhesion signal strength index; the chip adhesion signal strength index is fused with the collected resultant time domain signal to generate a vibration-force coupling data pair, and a preset interference stripping algorithm is applied to the vibration-force coupling data pair to separate the attached load time domain sequence and the pure cutting force time domain sequence; if the attached load time domain sequence exceeds the predefined threshold, a self-cleaning trigger signal is issued to drive the multi-blade wiper at the tail of the drill rod to work cooperatively with the directional jet cleaning nozzle to strip and discharge the accumulated chips in the deep hole; the pure cutting force time domain sequence is compared with the ideal cutting force reference to calculate the force deviation, and a local feed compensation instruction is generated based on the force deviation according to the preset feed compensation strategy; the local feed compensation instruction is executed and the machining is continued, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through the online measurement device, the correction effect is verified and the stripping and compensation parameter set is adjusted until the machining precision target is reached, so that the chip accumulation can be accurately identified and cleaning can be triggered, the real cutting force and the additional interference load can be effectively separated, and the feed parameter can be dynamically compensated, thereby significantly improving the deep hole machining precision and stability.

[0161] The present application effectively solves the precision fluctuation problem in deep hole drilling by constructing a complete dynamic correction system. The vibration sensing array can accurately capture abnormal vibration characteristics caused by chip accumulation, realize real-time identification of chip accumulation state, and provide reliable basis for subsequent intervention. The present application separates the load signal by means of vibration-force coupling model, can eliminate the additional interference caused by chip accumulation, accurately extracts the real cutting force, and lays a foundation for feed parameter adjustment. When the chip accumulation is detected to be over limit, the self-cleaning device of the present application can be triggered in time to remove the accumulated chips through the cooperative action of wiper and jet, avoiding the continuous accumulation of interference. Based on the feed compensation instruction generated by the real cutting force deviation, the present application can dynamically adjust the feed speed and cutting depth, real-time correct the machining trajectory, and reduce the hole diameter and guide error. The closed-loop verification mechanism of the present application continuously optimizes the separation parameters and compensation strategies through online measurement feedback results, ensures the stability of machining precision, and significantly improves the precision consistency and machining efficiency of deep hole drilling.

[0162] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more of the flow or blocks Figure 1 one or more of the flow or blocks

[0163] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer readable storage medium, including Read-Only Memory (ROM), Random Access Memory (RAM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), One-time Programmable Read-Only Memory (OTPROM), Electrically-Erasable Programmable Read-Only Memory (EEPROM), Compact Disc Read-Only Memory (CD-ROM) or other optical disk storage, magnetic disk storage, magnetic tape storage, or any other medium capable of carrying or storing data which can be read by a computer.

[0164] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, methods, articles or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or further include elements inherent in such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A deep hole drilling numerical control correction method based on force feedback, characterized in that, The method comprises: The vibration amplitude and frequency spectrum characteristics of the drill rod surface are monitored by using a micro vibration sensor array, and are compared with a normal cutting vibration characteristic library to extract a chip adhesion signal strength index; The chip adhesion signal strength index and the collected resultant time domain signal are fused to generate a vibration-force coupling data pair, a vibration-force coupling model is constructed, the vibration-force coupling data pair is input into the vibration-force coupling model based on a preset interference stripping algorithm, and an attached load time domain sequence and a pure cutting force time domain sequence are separated out; Collecting force time domain signal F through force sensor at main shaft end of drill rod total (t), removing low frequency workpiece vibration and high frequency noise in force time domain signal F total (t) through band-pass filter, cutting filtered force time domain signal F s (t) into equal-length sequence according to sampling rate U total and sampling time length T; The chip adhesion signal strength index S is updated to a chip adhesion vibration index S(t) according to an actual vibration sampling period; The time synchronization alignment is performed on the chip adhesion vibration index S(t) and the resultant force time domain signal F total (t) to generate a vibration-force coupling data pair. A vibration-force coupling model is constructed, and based on a preset interference stripping algorithm, vibration-force coupling data pairs are input into the vibration-force coupling model to calculate a time-domain sequence of the additional load F int (t); wherein, represents an additional load scaling factor obtained from offline calibration, represents a nonlinear correction coefficient obtained from offline fitting; combined force time-domain signal F total (t), the pure cutting force time-domain sequence F cut (t) is calculated. ； The pure cutting force time domain sequence is compared with an ideal cutting force reference to calculate a force deviation, and a local feed compensation instruction is generated based on the force deviation according to a preset feed compensation strategy; querying the ideal cutting force reference F corresponding to the offline calibration of the current machining condition from the process database ref , combined with the average cutting force F avg , to calculate the force deviation ΔF: According to the preset feed compensation strategy, the force deviation AF is mapped to a feed speed adjustment amount AV f : where K f represents the feed speed compensation gain of offline calibration; The force deviation ΔF is converted into a cutting depth adjustment amount ΔL according to a proportional relationship: ΔL = -K d ΔF In the formula, K d represents the cutting depth compensation gain of offline calibration; inserting an original feed segment at the current numerical control track point position, adjusting the original feed speed V0 to V0+ΔV f , generating a local feed speed instruction, and adjusting the original cutting depth L0 to L0+ΔL to generate a cutting depth increment instruction, and integrating the local feed speed instruction and the cutting depth increment instruction to generate a local feed compensation instruction; The local feed compensation instruction is executed and the machining is continued, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through an online measuring device, the correction effect is verified and the stripping and compensation parameter set is adjusted until the machining precision target is reached.

2. The force feedback based deep hole drilling NC correction method according to claim 1, characterized in that, The vibration amplitude and frequency spectrum characteristics of the drill rod surface are monitored by using a micro vibration sensor array, and are compared with a normal cutting vibration characteristic library to extract a chip adhesion signal strength index, specifically comprising: N micro piezoelectric vibration sensors are arranged equidistantly along the axial and circumferential directions of the drill rod shell, and the N micro piezoelectric vibration sensors are in close contact with the deep hole wall contact surface; According to the sampling rate U s With a sampling duration T, the output of each miniature piezoelectric vibration sensor is synchronously sampled using a high-speed analog-to-digital converter to generate a vibration time-domain signal matrix O=[O1(t), ..., O i (t), ..., O I [t], where I represents the total number of vibration frequency domain signals in the vibration time domain signal matrix, i represents the index of the vibration frequency domain signal in the vibration time domain signal matrix, t represents the current time, and the collected vibration time domain signal matrix O is stored in a circular buffer to form a C1×C2 dimensional matrix, C2=U s ×T, U s ≥10kHz; A band-pass filter is used to remove low-frequency workpiece vibrations and high-frequency noise from each vibration time-domain signal O i (t) and calculate the filtered vibration time-domain signal O i (t) i (t) = max |O i (t)| i (t) is subjected to a fast Fourier transform to obtain an amplitude spectrum h i [k], k = 1, …, M, where k represents the spectral line index, M represents the total number of spectral lines in the amplitude spectrum, and the current frequency spectrum H k is generated by averaging and aggregating the spectral lines. obtaining normal spectrum in normal cutting vibration feature library obtained by offline calibration , and calculating correlation degree of current spectrum H k with normal spectrum , to obtain chip adhesion signal intensity index S; If the decline amplitude of the chip adhesion signal strength index S exceeds the amplitude threshold, it is determined that there is accumulated chip in the deep hole, and a chip cleaning request signal is sent.

3. The force feedback based deep hole drilling NC correction method according to claim 2, characterized in that, Current spectrum H k The formula for the calculation is as follows: where FFT() represents a fast Fourier transform operation; The calculation formula of the chip adhesion signal strength index S is as follows: 。 4. The force feedback based deep hole drilling NC correction method according to claim 3, characterized in that, Average cutting force F avg The calculation formula is as follows: At the current machining position, the time domain sequence F w of the pure cutting force during the cutting duration T cut is intercepted, and the time average of the time domain sequence F w (t) of the pure cutting force during the cutting duration T cut is calculated as the average cutting force F avg : wherein denotes the integration variable.

5. The force feedback based deep hole drilling NC correction method according to claim 4, characterized in that, The local feed compensation instruction is executed and the machining is continued, the hole diameter deviation and the guide deviation after machining are fed back to the force separation module through an online measuring device, the correction effect is verified and the stripping and compensation parameter set is adjusted until the machining precision target is reached, specifically comprising: Receiving and executing local feed compensation instructions, measuring the processed deep hole diameter D through the electromagnetic caliper sensor assembled at the deep hole outlet meas (t), and measuring the drill pipe center line offset G through the laser triangulation guide sensor installed at the drill pipe front end meas (t), in combination with the diameter reference D ref and the guide reference G ref , calculating the diameter deviation ΔD(t)= D meas (t)- D ref and the guide deviation ΔG(t)= G meas (t)- G ref : calculating a maximum absolute deviation E based on the aperture deviation ΔD(t) and the guide deviation ΔG(t) max , obtaining an accuracy tolerance R tol , if E max ≤ R tol , the correction effect is qualified, otherwise the correction effect is unqualified, the stripping and compensation parameter set needs to be adjusted again, and the next round of stripping and compensation operation is continued until the machining accuracy target is reached.

6. The force feedback based deep hole drilling numerical control correction method according to claim 5, characterized in that, Maximum absolute deviation E max The formula for calculating E is as follows: 。

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