Novel high-integration coal mining machine inertial navigation system

Abstract

The invention relates to the technical field of mining machinery and intelligent control, in particular to a novel high-integration coal mining machine inertial navigation system which comprises a coal dust isolation measurement module, a coal seam vibration decoupling module, a dynamic reference correction module, a multi-source fusion calculation module and a cutting track generation module. Wherein the coal dust isolation measurement module is used for forming an annular air curtain and outputting clean inertial data; the coal seam vibration decoupling module is used for implementing feature matching notch filtering based on the inherent frequency spectrum of the coal seam; the dynamic reference correction module is used for adjusting a navigation reference surface and outputting reference correction data; the multi-source fusion resolving module is used for carrying out space-time alignment and outputting fusion attitude parameters; and the cutting track generation module is used for generating a three-dimensional adaptive cutting path. According to the method, through multi-source data anti-interference processing and dynamic path self-adaptive planning, the attitude calculation precision and the cutting track control capability of the coal mining machine in a complex coal seam environment are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mining machinery and intelligent control technology, and particularly relates to a novel high-integration shearer inertial navigation system. BACKGROUND

[0002] In a fully mechanized coal mining face, efficient and stable operation of the shearer is of key significance to overall production efficiency and operation safety. As an important supporting technology for shearer attitude and path control, the inertial navigation system (INS) usually relies on inertial sensors (such as gyroscopes and accelerometers) to provide high-frequency dynamic data to estimate the device attitude and trajectory in real time. However, due to the influence of the working environment, the shearer operation area has high coal dust concentration, severe vibration, and complex geological structure. The inertial navigation system is easily affected by factors such as coal dust interference, coal seam structure excitation noise, attitude reference drift, and multi-source data space-time inconsistency, resulting in attitude calculation error accumulation, navigation misalignment, and even cutting path deviation. At the same time, the irregularity of the coal-rock interface form puts higher adaptive requirements on the generation of the cutting path. The conventional trajectory planning method based on static models cannot respond to the dynamic changes of the coal-rock structure in real time, affecting the operation accuracy and device stability.

[0003] The existing technology still has significant deficiencies in terms of anti-interference, attitude reference stability, sensor data synchronization, and path planning adaptability of the inertial navigation system, and cannot meet the actual needs of high-precision cutting control under complex working conditions. On the one hand, the inertial sensor is easily affected by particle impact in the coal dust environment, resulting in an increase in signal noise. On the other hand, the high-frequency vibration caused by frequent changes in the coal seam structure will form inherent frequency band interference in the inertial navigation data, affecting the attitude solving accuracy. In addition, the existing multi-source data fusion method is mostly based on static time calibration, lacks a space-time alignment mechanism for the vibration characteristics of the device structure, and cannot realize the synchronous fusion of inertial and vibration signals under high-speed dynamic running conditions. SUMMARY

[0004] Based on the above purpose, the present application provides a novel high-integration shearer inertial navigation system.

[0005] A novel high-integration shearer inertial navigation system, comprising a coal dust isolation measurement module, a coal seam vibration decoupling module, a dynamic reference correction module, a multi-source fusion solving module, and a cutting trajectory generation module; wherein: The coal dust isolation measurement module is used to form a 0.5-0.8 MPa annular air curtain on the surface of the inertial sensor through the eddy current air film generator, and output clean inertial data. The coal seam vibration decoupling module is used to receive the clean inertial data, implement characteristic matching notch filtering based on the coal seam inherent frequency spectrum, and output decoupled inertial data. Dynamic reference correction module: used for receiving decoupled inertial data, and dynamically adjusting the navigation reference surface in combination with the real-time coal seam hardness distribution map, and outputting reference correction data; Multi-source fusion solving module: used for receiving reference correction data, and performing time-space alignment through a gyroscope-cutting motor vibration phase synchronization algorithm, and outputting fusion attitude parameters; Cutting trajectory generation module: used for receiving fusion attitude parameters, and generating a three-dimensional adaptive cutting path according to coal-rock interface reflected wave front characteristics.

[0006] Optionally, the coal dust isolation measurement module comprises a gas source pressure stabilizing unit, a ring-shaped air jet unit, a flow guide pressure control unit and a sensor protection cavity unit; wherein: The gas source pressure stabilizing unit is used for receiving raw gas from a high-pressure gas source, and controlling the gas pressure in the range of 0.5-0.8 MPa through a first-stage pressure stabilizing valve, and outputting stable gas flow; The ring-shaped air jet unit is used for uniformly jetting the stable gas flow to the periphery surface of the inertial sensor through the circumferentially distributed radial nozzles, forming a continuous closed gas film boundary, and constituting a ring-shaped air curtain; The flow guide pressure control unit is used for adjusting the cross-sectional size of each nozzle, so that the gas film forms a stable outward diffusion pressure gradient on the sensor surface, to block the coal dust particles from approaching the sensor sensing side; The sensor protection cavity unit is used for encapsulating the inertial sensor body, and is provided with an opening structure surrounded by the nozzles, to realize the integrated layout of clean air curtain isolation and measurement signal non-interference.

[0007] Optionally, the coal seam vibration decoupling module comprises a frequency characteristic extraction unit, a spectrum matching identification unit, a notch filter execution unit and a decoupling data output unit; wherein: The frequency characteristic extraction unit is used for receiving clean inertial data, and extracting the frequency domain characteristics in the acceleration and angular velocity signals through fast Fourier transform, to obtain an inertial response spectrum; The spectrum matching identification unit is used for calling a target frequency set corresponding to the current position from a pre-established coal seam inherent frequency spectrum database, and performing one-to-one corresponding matching with the current inertial response spectrum, to identify a coal seam excitation characteristic frequency band; The notch filter execution unit is configured with notch filter parameters based on the identified characteristic frequency band, to further suppress the interference of the coal seam inherent vibration frequency on the inertial data; The decoupling data output unit is used for reconstructing and outputting the filtered inertial data.

[0008] Optionally, the spectrum matching identification unit comprises: Locate the current spatial position: obtain the position information output by the inertial navigation system in real time; Target frequency set retrieval: retrieve the target frequency set corresponding to the structure type of the coal seam from the coal seam inherent frequency spectrum database indexed by the current spatial position ; Response frequency set construction: extract the frequency set from the inertial response spectrum ; Spectrum matching: perform the target frequency set and the response frequency set corresponding comparison, if the following matching conditions are met: , it is considered that the matching is successful, wherein is the frequency tolerance threshold.

[0009] Optionally, the dynamic reference correction module comprises a hardness atlas calling unit, a reference offset calculation unit, and a correction data output unit; wherein: Hardness atlas calling unit: used for receiving the current position coordinate information of the coal mining machine, and retrieving the local hardness distribution atlas corresponding to the position from the coal seam hardness distribution atlas database; Reference offset calculation unit: used for receiving the decoupled inertial attitude angle vector, and performing joint analysis combined with the retrieved hardness distribution atlas, determining the normal vector offset amount of the navigation reference surface based on the hardness gradient direction and intensity of the coal seam, and generating the corrected attitude angle vector accordingly; Correction data output unit: used for outputting the corrected attitude angle vector as navigation reference correction data, and transmitting it to the multi-source fusion solving module.

[0010] Optionally, the reference offset calculation unit comprises: Hardness gradient calculation: performing spatial difference operation on the called local hardness distribution atlas of the coal seam to obtain the gradient components of the coal seam hardness in the X, Y, and Z directions within the neighborhood of the current position, which are used to represent the directionality and intensity distribution of hardness change; Direction-sensitive region identification: identifying the hardness gradient mutation region or soft-hard boundary based on the gradient vector size and change, and determining the corresponding local normal vector offset direction; Reference surface offset determination: comparing the inertial decoupled attitude angle vector with the identified offset direction to determine whether the navigation reference surface needs to be adjusted, and determining the required normal vector offset amount according to the hardness change amplitude; Attitude angle correction: correcting the yaw angle, pitch angle, and roll angle of the current attitude angle vector according to the normal vector offset amount obtained by the determination, to generate the corrected attitude angle vector adapted to the actual coal seam structure.

[0011] Optionally, the multi-source fusion solving module comprises a vibration signal acquisition unit, a phase synchronization calculation unit, a time registration control unit, and an attitude fusion output unit; wherein: The vibration signal collection unit is configured to collect three-axis vibration signals of the cutting motor and angular velocity signals output by the gyroscope during operation respectively, and perform unified time sequence sampling based on a set sampling frequency to form vibration time sequences and angular velocity time sequences; The phase synchronization calculation unit is configured to perform frequency domain conversion on the vibration time sequences and the angular velocity time sequences respectively, extract phase information corresponding to main frequency components of the vibration time sequences and the angular velocity time sequences respectively, and construct a phase difference vector. The time registration control unit is configured to dynamically adjust a time stamp of a gyroscope data stream based on the phase difference vector, so that the gyroscope data stream is synchronized and aligned with the main frequency components of the motor vibration on a time axis, and an inertial-vibration fusion data set under a unified reference time window is formed. The attitude fusion output unit is configured to perform fusion operation on the corrected inertial attitude angle vector and the navigation reference correction data, and output a spatiotemporally consistent fusion attitude parameter.

[0012] Optionally, the phase synchronization calculation unit comprises: Signal preprocessing: the vibration signals of the cutting motor and the angular velocity signals of the gyroscope are normalized respectively, and a window function is applied for weighting to suppress frequency spectrum leakage; The frequency domain conversion step: the vibration signals and the angular velocity signals subjected to the weighting processing are subjected to fast Fourier transform respectively, so that time domain signals are converted into frequency domain signals, and complex spectrum data corresponding to each frequency point are obtained; Main frequency extraction: amplitude analysis is performed on the converted frequency domain data, dominant frequency components of the vibration signals and the angular velocity signals in the frequency domain are identified, and frequency positions corresponding to the dominant frequency components are recorded; Phase difference calculation: phase angle information of the main frequency components of the vibration signals and the angular velocity signals in the frequency domain is extracted, a phase difference vector representing a relative delay relationship between the vibration signals and the angular velocity signals is constructed by comparing phase angle difference values of the main frequencies.

[0013] Optionally, the time registration control unit comprises: Time delay estimation: according to the phase difference value output by the phase synchronization calculation unit , and in combination with a period corresponding to the main frequency , a time delay of the gyroscope data relative to the motor vibration signals is calculated , and the formula is as follows: ; Time stamp correction: each sampling point time stamp in the original gyroscope data stream is offset and corrected to generate a corrected time stamp ; Synchronized data construction: based on the corrected gyroscope time sequence and the original vibration signal time sequence , a unified time window and linearly interpolating or resampling the inertial data and the vibration data in the window to generate a time-synchronized fused data pair .

[0014] Optionally, the cutting trajectory generation module comprises a reflected wave feature extraction unit, a path adaptive planning unit and a trajectory generation unit;Wherein: The reflected wave feature extraction unit is used for receiving the fused attitude parameters output from the multi-source fusion solving module, and combining the sensor data related to the coal-rock interface, analyzing and extracting the front edge features of the interface reflected wave, so as to obtain the geometric profile, curvature change and edge information of the coal-rock interface, so as to represent the morphological characteristics of the coal-rock interface; The path adaptive planning unit is based on the interface feature information extracted by the reflected wave feature extraction unit and the fused attitude parameters, and performs three-dimensional environment modeling and region division to dynamically calculate the cutting path planning scheme meeting the working condition requirements; The trajectory generation unit converts the planning result output by the path adaptive planning unit into specific three-dimensional cutting trajectory and generates operation instruction, so as to guide the cutting device to work accurately according to the predetermined path.

[0015] The beneficial effects of the present application are: The present application improves the purity and stability of inertial data through coal dust isolation, vibration decoupling and reference correction technology, solves the navigation error caused by coal dust interference and coal seam excitation, and ensures the attitude sensing accuracy of inertial navigation system in complex environment.

[0016] The present application dynamically generates cutting path by fusing attitude parameters and interface features, realizes adaptive response to coal-rock interface change, improves path fitting degree and operation safety, and meets the actual needs of fully mechanized coal face for high-precision navigation and trajectory control. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only illustrate the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Fig. 1 It is a schematic diagram of the coal mining machine inertial navigation system of the embodiment of the present application; Fig. 2 It is a schematic diagram of the multi-source fusion solving module of the embodiment of the present application. DETAILED DESCRIPTION

[0019] The application will be described in detail below with reference to the drawings and specific embodiments. It should be noted here that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and other alternative ways can also be used by those skilled in the art to implement them; and the drawings are only used to more specifically describe the embodiments, and are not intended to specifically limit the application.

[0020] As shown in Figs. 1-2 A new high-integration coal mining machine inertial navigation system includes a coal dust isolation measurement module, a coal seam vibration decoupling module, a dynamic reference correction module, a multi-source fusion solving module, and a cutting trajectory generation module; wherein: The coal dust isolation measurement module is used to form a 0.5-0.8 MPa annular air curtain on the surface of the inertial sensor through the eddy current air film generator, and output clean inertial data; The coal seam vibration decoupling module is used to receive clean inertial data, implement characteristic matching notch filtering based on the inherent frequency spectrum of the coal seam, and output decoupled inertial data; The dynamic reference correction module is used to receive decoupled inertial data, and dynamically adjust the navigation reference surface in combination with the real-time coal seam hardness distribution map, and output reference correction data; The multi-source fusion solving module is used to receive reference correction data, and perform time and space alignment through a gyroscope-cutting motor vibration phase synchronization algorithm, and output fusion attitude parameters; The cutting trajectory generation module is used to receive fusion attitude parameters, and generate a three-dimensional adaptive cutting path according to the coal-rock interface reflected wave front edge characteristics.

[0021] The coal dust isolation measurement module includes a gas source pressure stabilizing unit, an annular jet unit, a flow guide pressure control unit, and a sensor protection cavity unit; wherein: The gas source pressure stabilizing unit is used to receive raw gas from a high-pressure gas source, and control the gas pressure in the range of 0.5-0.8 MPa through a primary pressure stabilizing valve, and output stable gas flow; The annular jet unit is used to uniformly spray the stable gas flow to the periphery surface of the inertial sensor through the circumferentially distributed radial nozzles, form a continuous closed air film boundary, and constitute an annular air curtain; The flow guide pressure control unit is used to adjust the cross-sectional size of each nozzle, so that the air film forms a stable outward diffusion pressure gradient on the sensor surface, to block the coal dust particles from approaching the sensor sensing side; The sensor protection cavity unit is used for packaging the inertial sensor body and is provided with an opening structure surrounded by the nozzle, so that the clean gas curtain isolation and the measurement signal non-interference integrated layout are realized, and clean inertial data are output; through the design of the above-mentioned unit, the coal dust isolation measurement module can form a stable high-pressure annular gas curtain barrier to the inertial sensor in a strong coal dust environment, effectively isolate the particulate matter interference, ensure that the original data collected by the inertial navigation system have high cleanliness and stability, and provide reliable input for subsequent vibration decoupling and reference correction.

[0022] The coal seam vibration decoupling module comprises a frequency characteristic extraction unit, a spectrum matching identification unit, a notch filter execution unit and a decoupling data output unit; wherein: The frequency characteristic extraction unit is used for receiving clean inertial data and extracting frequency domain characteristics in acceleration and angular velocity signals through fast Fourier transform to obtain an inertial response spectrum; The specific extraction steps are as follows: Signal sampling: the three-axis acceleration signals and three-axis angular velocity signals collected by the inertial sensor are periodically sampled, and the calculation formula of the sampling point number is: , wherein F is the sampling frequency, T is the sampling time length, and N is the sampling point number; Window function processing: assuming that a channel discrete signal is , the window function is , and the original signal is windowed to obtain: , wherein is the original inertial signal of the nth sampling point; is the window function weight value of the nth sampling point; is the signal value after windowing processing; Fast Fourier transform: the windowed signal is subjected to fast Fourier transform to obtain a frequency domain complex sequence , and the expression is: , wherein is the complex spectrum value corresponding to the kth frequency point; j is an imaginary unit, satisfying ; k is a frequency domain index, representing the kth frequency point; Amplitude spectrum extraction: the complex spectrum is converted into an amplitude spectrum , and the calculation formula is: , wherein is the amplitude spectrum value of the kth frequency point; is the real part of the complex ; is the imaginary part of the complex ; Frequency axis mapping: the frequency point index k is mapped into an actual frequency value , and the mapping formula is: ,in, : The frequency value corresponding to the k-th frequency point; F is the sampling frequency; k is the frequency point index; reserved Using the spectral data, construct the inertial response spectrum: ,in, For frequency The corresponding response amplitude; Output results: Output inertial response spectrum data. The spectrum matching and recognition unit performs characteristic frequency band identification and notch filter configuration.

[0023] Spectrum matching and identification unit: used to retrieve the target frequency set corresponding to the current position from the pre-established coal seam inherent frequency spectrum database, and match it one-to-one with the current inertial response spectrum to identify the coal seam excitation characteristic frequency band; Notch filter execution unit: Based on the identified characteristic frequency bands, configure notch filter parameters to suppress the interference of the coal seam's inherent vibration frequency on inertial data and keep the navigation-related effective frequency band signals undistorted; Decoupling data output unit: used to reconstruct and output the filtered inertial data as input to the subsequent dynamic reference correction module; through the synergistic effect of the above units, the coal seam vibration decoupling module can accurately identify and filter out the interference of the inherent excitation frequency of the coal seam on the inertial sensor data, while retaining the effective components of navigation attitude information, to achieve high-precision vibration decoupling processing, providing a clean signal basis for downstream navigation reference correction and attitude calculation.

[0024] The spectral matching recognition unit includes: Determine current spatial position: Obtain the real-time position information output by the inertial navigation system. ,in These represent the three-dimensional coordinates of the current position of the coal mining machine, used to locate the current coal seam area; Retrieve target frequency set: based on current spatial location As an index, the target frequency set corresponding to the coal seam structure type is retrieved from the coal seam inherent frequency spectrum database. Its expression is: ,in, For the target frequency set; Represents the inherent frequency component of the i-th coal seam; n is the number of target frequencies; Constructing the response frequency set: Extracting the frequency set from the inertial response spectrum Its expression is: ,in, For the current response frequency set; For frequency points in the spectrum; This represents the amplitude at the corresponding frequency point; Response amplitude filter threshold value; Implementing spectrum matching: matching the target frequency set with the response frequency set is performed - corresponding comparison, if the following matching conditions are met: is considered to be matched successfully, wherein is the frequency tolerance threshold value, used to define the acceptable matching error range; through the above steps, the spectrum matching identification unit can automatically retrieve the inherent frequency characteristics corresponding to the current coal seam area based on the inertial real-time positioning result, and match with the measured frequency spectrum data, accurately identify the coal seam excitation frequency band, and provide clear targets for dynamic configuration of the notch filter.

[0025] The dynamic reference correction module includes a hardness map calling unit, a reference offset calculation unit, and a correction data output unit; wherein: The hardness map calling unit: used to receive the current position coordinate information of the coal mining machine, and call the local hardness distribution map corresponding to the position from the coal seam hardness distribution map database, used to represent the hardness change characteristics of the coal seam around the current position; The reference offset calculation unit: used to receive the decoupled inertial attitude angle vector, and jointly analyze combined with the called hardness distribution map, determine the normal vector offset amount of the navigation reference surface based on the coal seam hardness gradient direction and intensity, and generate the corrected attitude angle vector accordingly; The correction data output unit: used to output the corrected attitude angle vector as navigation reference correction data, and transmit it to the multi-source fusion calculation module; the above units can realize real-time dynamic adjustment of the navigation reference surface through joint analysis of the coal seam hardness distribution map and inertial attitude data, improve the self-adaptability of the inertial navigation system to the change of the coal seam structure, and ensure the consistency of the navigation reference with the actual geological conditions, providing more stable input data for attitude fusion calculation.

[0026] The reference offset calculation unit includes: Hardness gradient calculation: spatial difference operation is performed on the called local hardness distribution map of the coal seam to obtain the gradient components of the coal seam hardness in X, Y, and Z directions in the neighborhood of the current position, used to represent the directionality and intensity distribution of hardness change; Direction sensitive area identification: according to the size and change of the calculated gradient vector, the hardness gradient mutation area or the soft-hard boundary is identified, and the corresponding local normal vector offset direction is determined; Reference surface offset determination: compare the inertial decoupled attitude angle vector with the identified offset direction to determine whether the navigation reference surface needs to be adjusted, and determine the required normal vector offset amount according to the hardness change amplitude; The attitude angle correction step: according to the normal vector offset obtained by the judgment, the yaw angle, the pitch angle and the roll angle of the current attitude angle vector are corrected, a corrected attitude angle vector adapted to the actual coal seam structure is generated, and is used for subsequent navigation reference output.

[0027] The specific calculation steps are as follows: The hardness gradient calculation step: for the called coal seam local hardness distribution map The three-dimensional difference operation is implemented, and the hardness gradient components in three directions in the neighborhood of the current position are calculated , and the calculation formula is as follows: , and , and a three-dimensional hardness gradient vector G is constructed , wherein: is the local coal seam hardness distribution map; respectively, the gradient components in the direction; G is the three-dimensional hardness gradient vector; The direction sensitive area identification step: the modulus operation is performed on the gradient vector G to obtain the hardness change intensity M, and the calculation formula is: , then M is compared with the set sensitive threshold , if , the current position is marked as a direction sensitive area, and the gradient unit vector U is taken as the offset direction reference, and the expression is: ; The reference surface offset judgment step: the normal vector of the original navigation reference surface is , the unit vector derived from the direction sensitive area is U, and the included angle between them is calculated. The calculation formula is: ; then the attitude adaptability threshold of the preset navigation system is , when the included angle exceeds the threshold, it is considered that the current navigation reference surface has a directional deviation from the coal seam structure, and the attitude needs to be corrected; The attitude angle correction step: the offset angle is mapped to the attitude angle correction amount vector, and is added to the original attitude angle vector to obtain the corrected attitude angle vector; through the above steps, the reference offset calculation unit can dynamically determine whether the navigation reference surface needs to be adjusted in combination with the spatial hardness gradient information, and accurately correct the attitude angle according to the coal seam structure change, so as to provide a structure consistent reference coordinate system for downstream attitude fusion operation.

[0028] The multi-source fusion solving module includes a vibration signal acquisition unit, a phase synchronization calculation unit, a time registration control unit and an attitude fusion output unit; wherein: The vibration signal acquisition unit is used for respectively acquiring three-axis vibration signals of the cutting motor in the running process and angular velocity signals output by the gyroscope, and performing unified time sequence sampling based on a set sampling frequency to form vibration time sequences and angular velocity time sequences. The phase synchronization calculation unit is used for respectively performing frequency domain conversion on the vibration time sequences and the angular velocity time sequences, extracting phase information corresponding to respective main frequency components, and constructing a phase difference vector. The time registration control unit is used for dynamically adjusting a gyroscope data stream timestamp based on the phase difference vector, so that the gyroscope data stream timestamp is synchronized and aligned with the main frequency component of the motor vibration on a time axis to form an inertial-vibration fusion data set under a unified reference time window. The attitude fusion output unit is used for performing fusion operation on the corrected inertial attitude angle vector and the navigation reference correction data to output a spatiotemporally consistent fusion attitude parameter as an input basis of the cutting trajectory generation module. The above units can realize accurate spatiotemporal alignment of the inertial navigation data and the mechanical structure vibration state by introducing the phase synchronization mechanism of the gyroscope and the cutting motor vibration signal, effectively compensate for the phase drift of the inertial navigation data possibly generated under the cutting working condition, improve the real-time performance and spatial consistency of the attitude solution, and ensure that the subsequent cutting path generation is based on accurate attitude.

[0029] The phase synchronization calculation unit includes: Signal preprocessing: the vibration signal of the cutting motor and the angular velocity signal of the gyroscope are respectively normalized, and a window function is applied for weighting to suppress spectrum leakage and enhance the recognition effect of the main frequency component; The frequency domain conversion step: the vibration signal and the angular velocity signal after the weighting processing are respectively subjected to fast Fourier transform to convert the time domain signal into a frequency domain signal, and complex spectrum data corresponding to each frequency point are obtained; Main frequency extraction: amplitude analysis is performed on the converted frequency domain data to identify the dominant frequency components of the vibration signal and the angular velocity signal in the frequency domain, and the frequency position corresponding to the dominant frequency is recorded; Phase difference calculation: the phase angle information of the main frequency components of the vibration signal and the angular velocity signal in the frequency domain is extracted, the phase angle difference value of the main frequencies of the two is compared, a phase difference vector representing the relative delay relationship between them is constructed, and is used for subsequent time sequence alignment operation.

[0030] The calculation steps of constructing the phase difference vector are as follows: Signal preprocessing: the vibration time sequence of the cutting motor and the angular velocity time sequence of the gyroscope are subjected to normalization and window function weighting processing to obtain preprocessed signals and , and the expressions are respectively: and , wherein, and the vibration and angular velocity signals of the nth sampling point, respectively; the window function weight value of the nth sampling point; and the windowed signal; frequency domain conversion: performing fast Fourier transform on the windowed and obtain the frequency domain complex spectrum and ; main frequency extraction: calculate the amplitude spectrum of each frequency point, and find the main frequency index of the vibration signal and the angular velocity signal; phase difference calculation: extract the phase angle information at the main frequency index, and record them as and , and then construct the phase difference vector: wherein, the phase angles corresponding to the main frequencies of the vibration signal and the angular velocity signal, respectively; the phase difference between the main frequency components of the two signals.

[0031] The time registration control unit comprises: time delay estimation: according to the phase difference value output by the phase synchronization calculation unit, and in combination with the period corresponding to the signal main frequency, calculate the time delay of the gyroscope data relative to the motor vibration signal, the formula is: ; timestamp correction: offset correction is performed on the timestamp of each sampling point in the original gyroscope data stream to generate the corrected timestamp , the correction formula is: wherein, is the original timestamp of the i th sampling point; is the corrected timestamp; synchronous data construction: based on the corrected gyroscope time sequence and the original vibration signal time sequence , construct a unified time window , and perform linear interpolation or resampling on the inertial data and vibration data in the window to generate the time-synchronous fusion data pair , which is represented as: wherein, is the sampling point on the unified time axis; is the fusion data pair at the k th synchronous sampling point; is the angular velocity value after delay correction; The original vibration signal value; by accurately estimating the time delay based on the phase difference and correcting the gyroscope timestamp, the time registration control unit can unify the inertial signal and the vibration signal into the same time reference frame, realize high-precision timing alignment, and thus provide consistent and highly synchronized data input for subsequent attitude fusion.

[0032] The cutting trajectory generation module includes a reflected wave feature extraction unit, a path adaptive planning unit, and a trajectory generation unit; wherein: The reflected wave feature extraction unit: used to receive the fusion attitude parameters output from the multi-source fusion solving module, and combined with the sensor data related to the coal-rock interface, analyzes and extracts the front edge features of the interface reflected wave, so as to obtain the geometric profile, curvature change and edge information of the coal-rock interface, to represent the morphological characteristics of the coal-rock interface; The path adaptive planning unit: based on the interface feature information extracted by the reflected wave feature extraction unit and the fusion attitude parameters, three-dimensional environment modeling and region division are carried out, and the cutting path planning scheme meeting the working condition requirements is dynamically calculated; The specific calculation steps are as follows: Parameter extraction: using the coal-rock interface morphological information output by the reflected wave feature extraction unit, the interface position data, local gradient direction and local curvature information are extracted, specifically, the interface position vector is denoted as , wherein s represents the parameter along the interface arc length; the interface gradient vector is denoted as , reflecting the local change trend of the interface; the interface curvature is denoted as , used to represent the bending degree of the interface; Cost function construction: according to the requirements of the coal mining working condition, a cost function describing the smoothness of the cutting path and the fitting degree with the coal-rock interface is constructed, and the expression of the constructed cost function J is: , wherein, is the position vector of the planned cutting path in three-dimensional space; is the tangent vector of the path, reflecting the local direction of the path; is the curvature vector of the path, reflecting the bending degree of the path; is the weight coefficient reflecting the fitting requirement of the path with the interface gradient; is the weight coefficient reflecting the smoothness requirement of the path; L is the total arc length of the path; Optimization solution: by solving the optimization problem of the above cost function, using the finite element optimization algorithm, the path function that makes the cost function J reach the minimum value is obtained; the optimization process ensures that the planned cutting path meets the smoothness and continuity requirements while fitting the coal-rock interface features as much as possible.

[0033] The trajectory generation unit: the planning result output by the path adaptive planning unit is converted into specific three-dimensional cutting trajectory, and operation instruction is generated, so as to guide the cutting device to accurately work according to the predetermined path; through the synergistic effect of the above units, the cutting trajectory generation module can fully utilize the fusion of the posture parameters and the coal-rock interface reflection wave front feature, realize the real-time perception and accurate modeling of the coal-rock interface form, dynamically plan the three-dimensional cutting path adapting to the complex geological structure, provide accurate and efficient path guidance for the cutting process of the coal mining machine, and significantly improve the overall operation safety and production efficiency.

[0034] The present application encompasses any substitutions, modifications, equivalent methods and schemes made on the essence and scope of the present application. In order to make the public have a thorough understanding of the present application, specific details are described in the following preferred embodiments of the present application, and the present application can also be fully understood without the description of these details to those skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the present application, well-known methods, processes, procedures, elements and circuits are not described in detail.

[0035] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. A novel high-integration coal mining machine inertial navigation system, characterized in that, The coal dust isolation measurement module, the coal seam vibration decoupling module, the dynamic reference correction module, the multi-source fusion solving module, and the cutting trajectory generation module are included. The coal dust isolation measurement module is used to form a 0.5-0.8 MPa annular air curtain on the surface of the inertial sensor through the vortex air film generator, and output clean inertial data. The coal seam vibration decoupling module is used to receive the clean inertial data, implement characteristic matching notch filtering based on the inherent frequency spectrum of the coal seam, and output decoupled inertial data. The dynamic reference correction module is used to receive the decoupled inertial data, dynamically adjust the navigation reference surface in combination with the real-time coal seam hardness distribution map, and output reference correction data. The multi-source fusion solving module is used to receive the reference correction data, perform time and space alignment through a gyroscope-cutting motor vibration phase synchronization algorithm, and output fusion attitude parameters. The cutting trajectory generation module is used to receive the fusion attitude parameters, and generate a three-dimensional adaptive cutting path according to the coal-rock interface reflection wave front edge characteristics.

2. A novel high-integration coal mining machine inertial navigation system according to claim 1, characterized in that, The coal dust isolation measurement module includes a gas source pressure stabilizing unit, an annular jet unit, a flow guide pressure control unit, and a sensor protection cavity unit. The gas source pressure stabilizing unit is used to receive raw gas from a high-pressure gas source, control the gas pressure in the range of 0.5-0.8 MPa through a primary pressure stabilizing valve, and output stable gas flow. The annular jet unit is used to uniformly spray the stable gas flow to the periphery surface of the inertial sensor through the circumferentially distributed radial nozzles, form a continuous closed air film boundary, and constitute an annular air curtain. The flow guide pressure control unit is used to adjust the cross-sectional size of each nozzle, so that the air film forms a stable outward diffusion pressure gradient on the sensor surface, to block the coal dust particles from approaching the sensor sensing side. The sensor protection cavity unit is used to encapsulate the inertial sensor body, and is provided with an open hole structure around the nozzles, to realize the integrated layout of clean air curtain isolation and measurement signal without interference.

3. A novel high-integration coal mining machine inertial navigation system according to claim 1, characterized in that, The coal seam vibration decoupling module includes a frequency characteristic extraction unit, a spectrum matching identification unit, a notch filtering execution unit, and a decoupled data output unit. The frequency characteristic extraction unit is used to receive clean inertial data, extract frequency domain characteristics in acceleration and angular velocity signals through fast Fourier transform, and obtain an inertial response spectrum. The spectrum matching identification unit is used to retrieve a target frequency set corresponding to the current position from a pre-established coal seam inherent frequency spectrum database, and perform one-to-one matching with the current inertial response spectrum to identify the coal seam excitation characteristic frequency band. The notch filtering execution unit configures notch filter parameters based on the identified characteristic frequency band, and then suppresses the interference of the coal seam inherent vibration frequency on the inertial data. The decoupled data output unit is used to reconstruct and output the filtered inertial data.

4. A novel high-integration coal mining machine inertial navigation system according to claim 3, characterized in that, The spectrum matching identification unit includes: Locate the current spatial position: obtain the position information output by the inertial navigation system in real time. Retrieving target frequency set: retrieving the target frequency set corresponding to the structure type of the coal seam from the coal seam inherent frequency spectrum database with the current spatial position as the index ; Constructing a response frequency set: extracting a set of frequencies from an inertial response spectrum ; Implementing spectrum matching: on target frequency set with response frequency set is performed - corresponding comparison, if the following matching conditions are met: then the matching is considered successful, where is the frequency tolerance threshold.

5. A novel high-integration coal mining machine inertial navigation system according to claim 1, characterized in that, The dynamic reference correction module includes a hardness map calling unit, a reference offset calculation unit, and a correction data output unit. The hardness map calling unit is used to receive the current position coordinate information of the coal mining machine, and retrieve the local hardness distribution map corresponding to the position from the coal seam hardness distribution map database. The benchmark offset calculation unit is configured to receive the decoupled inertial attitude angle vector, and perform joint analysis in combination with the retrieved hardness distribution map, determine the normal vector offset of the navigation benchmark surface based on the hardness gradient direction and intensity of the coal seam, and generate a corrected attitude angle vector accordingly; The corrected data output unit is configured to output the corrected attitude angle vector as navigation benchmark correction data, and transmit the navigation benchmark correction data to the multi-source fusion calculation module.

6. A novel high-integration coal mining machine inertial navigation system according to claim 5, characterized in that, The benchmark offset calculation unit comprises: Hardness gradient calculation: performing spatial difference operation on the called local hardness distribution map of the coal seam to obtain gradient components of the coal seam hardness in X, Y and Z directions in the neighborhood of the current position, which are used to represent the directionality and intensity distribution of hardness change; Direction-sensitive region identification: identifying the hardness gradient mutation region or soft-hard boundary based on the calculated gradient vector size and change, and determining the corresponding local normal vector offset direction; Benchmark surface offset determination: comparing the inertial decoupled attitude angle vector with the identified offset direction to determine whether the navigation benchmark surface needs to be adjusted, and determining the required normal vector offset based on the hardness change amplitude; Attitude angle correction: correcting the yaw angle, pitch angle and roll angle of the current attitude angle vector based on the determined normal vector offset to generate a corrected attitude angle vector that is adapted to the actual coal seam structure.

7. A novel high-integration coal mining machine inertial navigation system according to claim 1, characterized in that, The multi-source fusion calculation module comprises a vibration signal acquisition unit, a phase synchronization calculation unit, a time registration control unit and an attitude fusion output unit; wherein: The vibration signal acquisition unit is configured to acquire three-axis vibration signals of the cutting motor during operation and angular velocity signals output by the gyroscope respectively, and perform unified time sequence sampling based on a set sampling frequency to form vibration time sequences and angular velocity time sequences; The phase synchronization calculation unit is configured to perform frequency domain conversion on the vibration time sequences and angular velocity time sequences respectively, extract phase information corresponding to the main frequency components of each other, and construct a phase difference vector; The time registration control unit is configured to dynamically adjust the time stamp of the gyroscope data stream based on the phase difference vector, so that the main frequency components of the motor vibration are synchronized and aligned on the time axis, forming an inertial-vibration fusion data set under a unified reference time window; The attitude fusion output unit is configured to perform fusion operation on the corrected inertial attitude angle vector and the navigation benchmark correction data, and output spatiotemporally consistent fusion attitude parameters.

8. A novel high-integration coal mining machine inertial navigation system according to claim 7, characterized in that, The phase synchronization calculation unit comprises: Signal preprocessing: normalizing the vibration signals of the cutting motor and the angular velocity signals of the gyroscope respectively, and applying a window function for weighting to suppress frequency spectrum leakage; Frequency domain conversion step: performing fast Fourier transform on the weighted vibration signals and angular velocity signals to convert the time domain signals into frequency domain signals, and obtaining complex spectrum data corresponding to each frequency point; Main frequency extraction: performing amplitude analysis on the converted frequency domain data to identify the dominant frequency components of the vibration signals and angular velocity signals in the frequency domain, and recording the frequency position corresponding to the dominant frequency; Phase difference calculation: extract the phase angle information of the main frequency components of the vibration signal and the angular velocity signal in the frequency domain, and construct a phase difference vector representing the relative delay relationship between them by comparing the phase angle difference of the main frequency.

9. A novel high-integration coal mining machine inertial navigation system according to claim 8, characterized in that, The time registration control unit comprises: Time delay estimation: calculate the time delay of the gyroscope data relative to the motor vibration signal according to the phase difference value output by the phase synchronization calculation unit , combined with the period corresponding to the signal main frequency , the formula is: ;​ Timestamp correction: offset correction is performed on each sample point timestamp in the raw data stream of the gyroscope to generate a corrected timestamp ; Synchronous data construction: with corrected gyroscope time series and raw vibration time series as a basis, construct a unified time window and within this window, linearly interpolate or resample the inertial data and vibration data to generate a time-synchronous fused data pair .

10. A novel high-integration coal mining machine inertial navigation system according to claim 1, characterized in that, The cutting trajectory generation module comprises a reflected wave feature extraction unit, a path adaptive planning unit and a trajectory generation unit; wherein: The reflected wave feature extraction unit is used for receiving the fusion attitude parameters output from the multi-source fusion solution module, combining the sensor data related to the coal-rock interface, analyzing and extracting the front edge characteristics of the interface reflected wave, and obtaining the geometric profile, curvature change and edge information of the coal-rock interface to represent the morphological characteristics of the coal-rock interface; The path adaptive planning unit is used for three-dimensional environment modeling and region division based on the interface feature information extracted by the reflected wave feature extraction unit and the fusion attitude parameters, and dynamically calculates a cutting path planning scheme meeting the working condition requirements; The trajectory generation unit converts the planning result output by the path adaptive planning unit into a specific three-dimensional cutting trajectory and generates an operation instruction, thereby guiding the cutting device to work accurately according to the predetermined path.

Images