Direction monitoring device for roller of bolter miner based on digital control

Abstract

The invention relates to the technical field of digital control, in particular to a device for monitoring the direction of a roller of a bolter miner based on digital control, which is characterized in that a sensor module lays a physical time sequence difference foundation of positive and negative rotation through asymmetric double-sensor layout, and a feature extraction module locks reliable dynamic feature points from strong interference signals through adaptive filtering; the direction judgment module matches the current time sequence relation data with a preset mode, a direction signal is output only when continuous multi-period matching is successful, output is frozen immediately and an abnormal count is accumulated if an instantaneous conflict occurs, and reevaluation is started when a threshold value is continuously exceeded; therefore, multiple protection is constructed from a physical layer to a logic layer, and the potential safety hazard of triggering equipment misoperation due to single-time signal distortion in a traditional method is solved.

Description

Technical Field

[0001] This invention relates to the field of digital control technology, specifically to a digitally controlled device for monitoring the direction of a roadheader's drum. Background Technology

[0002] In coal mine tunneling operations, roadheaders play a crucial role, and accurate monitoring of their drum rotation direction is essential for the safe and efficient operation of the equipment. Traditional monitoring methods, such as relying on a single speed sensor, encoder, or simple sensor combination, are clearly inadequate under the complex and harsh working conditions faced by roadheaders. These environments are filled with instantaneous strong interference from the impact of huge coal blocks or gangue, strong high-frequency vibration peaks caused by sudden changes in the equipment or geological conditions, and extreme situations such as a large amount of dust instantly adhering to the sensor. These instantaneous and strong external interferences can easily cause temporary and severe distortions in the dynamic signals output by the sensors, manifesting as signal distortion, loss of feature points, or the appearance of false feature points.

[0003] Traditional methods, due to their simple processing logic and lack of fault tolerance, are prone to momentary misjudgments of the drum rotation direction when dealing with such interference. For example, they may misjudge an ongoing forward rotation as a reverse rotation, or vice versa. If such misjudged signals are transmitted to the control system, they may trigger incorrect drive commands, leading to erratic equipment operation. This can cause minor issues like mechanical damage or drill jamming, or even serious production accidents that threaten personnel safety. Therefore, there is an urgent need for a new type of monitoring device that possesses strong anti-interference capabilities and can reliably determine the drum rotation direction under harsh working conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a digitally controlled drum direction monitoring device for roadheader and anchor machine to solve the problems mentioned in the background art. Specific technical problems include how to effectively prevent the drum rotation direction from being misjudged and abruptly changed during roadheader and anchor machine operation when encountering instantaneous and intense external interference such as impacts from large coal blocks or gangue, strong high-frequency vibration peaks, or a large amount of dust instantly adhering to a sensor, causing severe distortion of the correlation between a single sensor signal or multiple signals within a short period. This prevents situations where forward rotation is misjudged as reverse rotation or vice versa, thereby preventing the control system from triggering control errors due to misjudgment, and ultimately eliminating the resulting risks of equipment damage and personal safety accidents.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This digitally controlled anchor boring machine drum direction monitoring device includes a sensor module, a feature extraction module, and a direction determination module, wherein:

[0007] The sensor module is fixedly installed at an asymmetrical angular position on the outer circumferential surface of the tunneling and anchoring machine drum. Its core includes a first sensor unit and a second sensor unit. This unique asymmetrical installation design fundamentally ensures that the order and interval of the physical signal feature points detected by the first and second sensor units on the time axis have inherent and predictable stable differences when the drum is rotating in both forward and reverse directions. This stable temporal difference provides a reliable physical basis for the subsequent accurate determination of the rotation direction through pattern matching, becoming the foundation of the entire scheme.

[0008] The feature extraction module first performs a unique preprocessing process on the raw dynamic signals output by the first and second sensor units. This process employs a composite filtering method that combines adaptive dynamic range compression and rotational frequency enhancement. Specifically, it calculates the dynamic threshold range in real time based on the actual rotational frequency of the drum, allowing only signal components located within this main rotational frequency distribution band and whose amplitudes have been adjusted by the adaptive compression ratio to pass through. It dynamically suppresses the slow drift components of the sensors by continuously updating the amplitude reference offset, while effectively suppressing high-frequency noise pollution that exceeds the physical vibration characteristic frequency band of the drum. This preprocessing significantly improves the signal-to-noise ratio and effectively filters out high-amplitude transient interference caused by huge impacts, wideband high-frequency noise interference, and slow drift interference caused by dust adhesion, etc.

[0009] The feature extraction module then divides the preprocessed dynamic signal into rotational periods. The key is to detect reliable periodic zero-crossing points in the signal as the reference points for period segmentation. It is necessary to confirm that the duration fluctuations of multiple consecutive periods are within a preset stable range before an effective period reference mode is established. Finally, using the zero-crossing points that have passed the stability verification as boundaries, continuous single-period signal segments are accurately segmented. This method effectively avoids period segmentation errors caused by abnormal zero points due to instantaneous impact interference, ensuring the accuracy and reliability of the time reference for subsequent single-period analysis.

[0010] Within each segmented single cycle, the feature extraction module performs robust extraction of dynamic feature points; the sensor axis component that most significantly responds to the tangential motion response of the roller surface is selected for analysis, specifically including:

[0011] First, the envelope extraction algorithm is applied to obtain the envelope of the component signal waveform; all extreme points of this envelope appearing in the current period are identified; then, these extreme points are strictly screened in order, and finally only extreme points that simultaneously satisfy the following three candidate conditions are retained as reliable dynamic feature points for direction determination:

[0012] The absolute value of the amplitude at this point is greater than the absolute values ​​of the amplitudes of its immediate predecessor and successor extreme points, ensuring that it is a local significant peak; the signal change rate to the left of this point is positive and its absolute value is greater than the preset reference slope, and the signal change rate to the right of this point is negative and its absolute value is greater than the reference slope, confirming that it is a steep peak that conforms to physical laws; the deviation between the time when this candidate feature point appears in the current cycle and the average time when the same type of feature point appears in the last three cycles must be less than the dynamically set tolerance threshold to ensure time stability; the joint screening of these three conditions forms a powerful filter that can effectively eliminate most false or abnormal feature points caused by instantaneous impact interference, and can lock reliable feature information even if the signal is distorted due to interference; as a fault tolerance mechanism in extreme cases, if there is no candidate feature point that meets the above three strict conditions in the current cycle, it will automatically switch to analyzing the drum angular velocity signal component, and select the zero-crossing point where the angular velocity signal component first turns from negative to positive in the current cycle as a backup dynamic feature point to ensure that there are still feature points available for direction determination under extreme interference.

[0013] The direction determination module pre-stores templates representing the timing patterns of normal forward and reverse rotation of the roller, namely, forward timing mode and reverse timing mode; these modes specifically include two key constraints:

[0014] The permissible time difference interval for forward rotation is the reasonable range of values ​​allowed for the difference between the time when the feature point of the first sensor unit appears and the time when the feature point of the second sensor unit appears when the drum rotates forward. The forward sequence rule for forward rotation explicitly requires that the feature point of the first sensor unit must appear before the feature point of the second sensor unit. Similarly, the reverse timing mode includes the permissible time difference interval for reverse rotation and the reverse sequence rule, the latter requiring that the feature point of the second sensor unit appears before the feature point of the first sensor unit.

[0015] The direction determination module receives the current temporal relationship data output by the feature extraction module, which contains two core elements:

[0016] The time difference calculated by subtracting the time of appearance of the dynamic feature point of the second sensor unit from the time of appearance of the dynamic feature point of the first sensor unit; and the order marker defined by the sign of the time difference, intuitively indicating which sensor's point appears first.

[0017] The core decision logic of the direction determination module is designed as follows:

[0018] The current cycle is temporarily marked as a forward matching state only if the currently received time difference data falls within the permissible range of the forward time difference and conforms to the forward sequence rule; similarly, it is temporarily marked as a reverse matching state only if the time difference falls within the permissible range of the reverse time difference and conforms to the reverse sequence rule. This module only considers direction output when the aforementioned conditions are strictly met. Crucially, the output of the final direction signal is not based on the single-cycle matching result; it requires that the same direction state be stably matched for a preset number of cycle verification cycles, i.e., multiple consecutive cycles of forward matching or multiple consecutive cycles of reverse matching, before the final forward or reverse rotation signal is output. This continuous multi-cycle verification mechanism is the core guarantee against misjudgment caused by single-cycle or short-term interference.

[0019] When the current timing relationship data becomes abnormal, such as when the calculated time difference value exceeds the allowable range of both positive and negative time differences simultaneously, or when the sequence flag conflicts with both sequence rules, the direction determination module treats this situation as a momentary invalid interference source. In this case, the direction determination module will not change the current output state, but will maintain the output of the valid direction signal that has been confirmed and output in the previous rotation cycle, keeping the state stable. At the same time, a dedicated counter independent of the matching logic begins to accumulate and record this conflict event. The essence of this anti-interference mechanism is that only when the cumulative number of such conflict events reaches another preset conflict number threshold will a more stringent direction re-evaluation process be initiated to carefully assess whether the roller direction has actually changed, rather than just being caused by strong momentary interference. This mechanism prevents momentary interference from causing erroneous changes in the direction signal.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] By integrating an asymmetric dual-sensor layout, robust multi-level signal processing and feature extraction technology, and intelligent decision logic based on continuous multi-cycle time-series pattern matching verification, the anti-interference capability and reliability of the roadheader drum direction monitoring device are enhanced under harsh working conditions such as impacts from huge coal blocks, strong high-frequency vibration peaks, and instantaneous large-scale dust adhesion. Its core achievement lies in:

[0022] It efficiently identifies and filters signal distortion caused by instantaneous and intense external interference, and strongly prevents misjudgment of drum rotation direction and state jumps caused by short-term signal distortion. This effectively avoids erroneous operation of the control system based on misjudged signals, eliminating unexpected equipment actions, mechanical damage, and potential personnel safety threats caused by misjudgment of direction, providing a solid technical guarantee for safe and efficient coal mine production. The device's adaptive processing mechanism and multiple fault-tolerant strategies also give it good adaptability to engineering applications. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall modules of the present invention;

[0024] Figure 2 This is a schematic diagram of the anti-interference mechanism in the direction determination module of the present invention.

[0025] In the diagram: 100, sensor module; 200, feature extraction module; 300, orientation determination module. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Next, please refer to Figure 1 The present invention provides a technical solution: a digitally controlled tunneling and anchoring machine drum direction monitoring device, including a sensor module 100, a feature extraction module 200 and a direction determination module 300.

[0028] The sensor module 100 includes two independent sensing units, defined as the first sensing unit and the second sensing unit, respectively. The two sensing units are fixedly installed along the outer circumferential surface of the tunneling and anchoring machine drum at a preset asymmetrical angle position, that is, the included angle between the two units in the circumferential direction of the drum is not equal to 180°. This installation method causes a fixed time difference when the same physical feature point passes through the two sensing units when the drum rotates.

[0029] The feature extraction module 200 continuously receives dynamic signals (such as triaxial acceleration) output from the first and second sensing units and preprocesses the dynamic signals output from these two sensing units. This preprocessing employs a composite filtering method combining adaptive dynamic range compression and rotational frequency enhancement: First, it calculates the dynamic threshold range based on the current rotational frequency of the drum, retaining only key signal components that are within the main rotational frequency distribution range and whose amplitudes meet the adaptive compression ratio; simultaneously, it suppresses slowly drifting components by updating the amplitude reference offset in real time and synchronously suppresses high-frequency noise that exceeds the physical vibration characteristic frequency band of the drum, so that the output preprocessed signal retains rotation-related features while having enhanced stability waveform envelope characteristics, thus promoting the stability of subsequent dynamic feature point recognition.

[0030] The feature extraction module 200 divides the preprocessed dynamic signal into rotational periods. By detecting the periodic zero-crossing point of the dynamic signal as the period segmentation benchmark, after confirming that the fluctuation of the duration of multiple consecutive periods is within a stable range, an effective period reference is established, and the continuous single-period signal segments are segmented with the stable zero-crossing point as the boundary.

[0031] The feature extraction module 200 performs dynamic feature point extraction within a single period, specifically including:

[0032] Select the axial component of the dynamic signal that responds to the tangential motion of the roller surface as the analysis object (e.g., the tangential acceleration component of the triaxial acceleration);

[0033] The envelope of the signal waveform is obtained by an envelope extraction algorithm, and all extreme points of the envelope within a single cycle time range are identified.

[0034] The extreme points are sequentially filtered, and only those extreme points that simultaneously meet the following candidate conditions are retained as candidate feature points:

[0035] Local amplitude prominence: The absolute value of the amplitude of a candidate feature point is simultaneously greater than the absolute values ​​of the amplitudes of its predecessor adjacent extreme point and its successor adjacent extreme point;

[0036] Boundary steepness: The rate of change of the signal to the left of the candidate feature point is positive and the absolute value is greater than the reference slope, and the rate of change of the signal to the right is negative and the absolute value is greater than the reference slope (the reference slope is initialized by the average rate of change of the signal in the previous 10 cycles and dynamically updated).

[0037] Periodic position consistency: The deviation between the current period's candidate feature point occurrence time and the average occurrence time of the same feature point in the last three periods is less than the dynamic tolerance threshold (the dynamic tolerance threshold is a preset proportion of the current rotation period).

[0038] When only one candidate feature point remains after screening, it is directly determined as the dynamic feature point; when multiple candidate feature points exist, the extreme point with the largest absolute value of amplitude is selected as the dynamic feature point; if there is no candidate feature point that meets the conditions, switch to the drum angular velocity signal component and select the zero-crossing point of the signal component that first changes from negative to positive value within the period as the dynamic feature point.

[0039] The direction determination module 300 pre-stores two direction determination benchmark models, including a forward timing mode and a reverse timing mode, wherein:

[0040] Forward timing mode: includes the forward time difference allowable range (e.g. 0.04s to 0.06s) that the dynamic feature points should meet when they appear in the signals of the first sensing unit and the second sensing unit when the drum rotates forward, and the determined sequence rule, that is, the dynamic feature points of the first sensing unit appear before the dynamic feature points of the second sensing unit (forward sequence rule).

[0041] Reverse timing mode: includes the reverse time difference allowable range (e.g. -0.06s to -0.04s) during reverse rotation and the reverse sequence rule, that is, the dynamic feature points of the second sensing unit precede the dynamic feature points of the first sensing unit (reverse sequence rule).

[0042] The direction determination module 300 receives the current temporal relationship data (Δt, S) reflecting the times when dynamic feature points appear in the first sensor unit and the second sensor unit within the current rotation cycle, where Δt is the time difference and S is the order indicator. The calculation formula is as follows:

[0043] Δt = t1 - t2, S = sign(Δt), where t1 represents the time when the dynamic feature point of the first sensing unit appears, and t2 represents the time when the dynamic feature point of the second sensing unit appears; sign is a sign function. When Δt > 0, i.e., t1 > t2, then sign(Δt) = 1; when Δt < 0, i.e., t1 < t2, then sign(Δt) = -1; when Δt = 0, i.e., t1 = t2, then sign(Δt) = 0.

[0044] The direction determination module 300 outputs a corresponding forward rotation signal or reverse rotation signal only when the current timing relationship data matches the forward timing mode or the reverse timing mode. Specifically, this includes:

[0045] When the time difference Δt belongs to the positive time difference allowable interval and S conforms to the positive order rule (i.e. S=1), it is marked as a positive match;

[0046] When the time difference Δt belongs to the reverse time difference allowable interval and S conforms to the reverse order rule (i.e. S = -1), it is marked as a reverse match;

[0047] When the positive matching condition is met for N consecutive rotation cycles, a positive rotation signal is output; where N refers to the preset threshold number of cycle verifications (N is an integer greater than 1), and its specific value is determined by the drum speed range, environmental interference intensity, and safety level requirements.

[0048] When the reverse matching condition is met for N consecutive rotation cycles, a reverse rotation signal is output.

[0049] If the current time-series relation data (Δt, S) undergoes a transient change that conflicts with the time-series pattern, this transient change is ignored, and the direction signal of the previous stable state is maintained. That is, when the current time-series relation data (Δt, S) satisfies the condition that the time difference Δt exceeds the matching range or the order rule conflicts, the anti-interference mechanism is activated. Here, a time difference Δt exceeding the matching range means that Δt belongs to neither the forward time difference allowable interval nor the reverse time difference allowable interval. An order rule conflict means that even if Δt is within a certain time difference interval, the value of S contradicts the order rule required for that interval (e.g., when Δt belongs to the forward time difference allowable interval, but S conforms to the reverse order rule). The anti-interference mechanism specifically includes:

[0050] The current timing data is considered an invalid interference source and does not participate in the direction determination. The valid direction signal confirmed in the previous rotation cycle is maintained (i.e., the direction result verified by the most recent consecutive N cycles). The current conflict event is accumulated and recorded in an independent counter. The direction re-evaluation process is started only when the abnormal counter record value continuously reaches the preset threshold. The re-evaluation process clears the current continuous matching count, re-executes the pattern matching process (re-accumulates the consecutive N cycles of matching verification), and finally resets the abnormal counter.

[0051] Please see Figure 2 When the direction determination module 300 detects a momentary conflict signal (such as abnormal or mismatched sensor data), it immediately triggers a freeze output anti-interference mechanism to suspend the transmission of direction signals. At the same time, it starts an abnormal counter to accumulate the conflict events. When the abnormal count exceeds a preset threshold continuously, it automatically starts a re-evaluation process to re-analyze the sensor data. Only after continuous multi-cycle stable verification (no conflict or abnormal count not exceeding the threshold) will the direction determination module 300 unfreeze and output a valid direction signal.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A digitally controlled device for monitoring the direction of a roadheader's drum, characterized in that, It includes a sensor module (100), a feature extraction module (200), and a direction determination module (300), wherein: The sensor module (100) is used to fix the sensor at an asymmetrical angular position on the outer circumferential surface of the anchor boring machine drum. The sensor module (100) includes a first sensor unit and a second sensor unit. The feature extraction module (200) identifies dynamic feature points that continuously exist during the rotation of the drum from the dynamic signals output by the first sensor unit and the second sensor unit. The direction determination module (300) pre-stores a forward timing mode and a reverse timing mode; The direction determination module (300) receives current temporal relationship data reflecting the times when dynamic feature points appear in the first sensor unit and the second sensor unit within the current rotation cycle; The current timing relationship data is matched with the forward timing pattern and the reverse timing pattern respectively, and the corresponding forward rotation signal or reverse rotation signal is output only when the current timing relationship data matches the forward timing pattern or the reverse timing pattern; if the current timing relationship data undergoes an instantaneous change that conflicts with the timing pattern, the anti-interference mechanism is activated.

2. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 1, characterized in that, The feature extraction module (200) is used to perform preprocessing on the dynamic signal. This preprocessing employs a composite filtering method combining adaptive dynamic range compression and rotational frequency enhancement, specifically including: The dynamic threshold range is calculated based on the current rotation frequency of the drum, and only signal components that are within the main rotation frequency distribution range and whose amplitudes meet the adaptive compression ratio are retained. Slowly drifting components are suppressed by updating the amplitude reference offset in real time, and high-frequency noise that exceeds the physical vibration characteristic frequency band of the drum is suppressed simultaneously.

3. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 2, characterized in that, The feature extraction module (200) is used to divide the rotation period of the preprocessed dynamic signal, specifically including: The periodic zero-crossing point of the dynamic signal is used as the period segmentation benchmark; after confirming that the fluctuation of the duration of multiple consecutive periods is within a stable range, an effective period reference is established; and the continuous single-period signal segment is segmented with the stable zero-crossing point as the boundary.

4. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 3, characterized in that, The process by which the feature extraction module (200) extracts dynamic feature points within a single period includes: The axial component of the dynamic signal that responds to the tangential motion of the roller surface is selected as the analysis object; the envelope of the signal waveform is obtained through the envelope extraction algorithm, and all extreme points of the envelope in a single period are identified; the extreme points are sequentially screened, and only the extreme points that simultaneously meet the candidate conditions are retained as candidate feature points.

5. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 4, characterized in that, The candidate conditions specifically include: The absolute value of the amplitude of a candidate feature point is greater than the absolute value of the amplitude of its predecessor and successor adjacent extreme points; The rate of change of the signal to the left of the candidate feature point is positive and its absolute value is greater than the reference slope, while the rate of change of the signal to the right is negative and its absolute value is greater than the reference slope. The deviation between the current period's candidate feature point occurrence time and the average occurrence time of the same feature point in the most recent three periods is less than the dynamic tolerance threshold.

6. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 1, characterized in that, The forward timing mode in the direction determination module (300) includes the forward time difference allowable interval during forward rotation and the forward sequence rule that the feature points of the first sensor unit precede the feature points of the second sensor unit; the reverse timing mode in the direction determination module (300) includes the reverse time difference allowable interval during reverse rotation and the reverse sequence rule that the feature points of the second sensor unit precede the feature points of the first sensor unit.

7. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 6, characterized in that, The current time sequence data in the direction determination module (300) includes a time difference and a sequence flag, wherein the time difference is the difference between the time when the dynamic feature point of the first sensor unit appears and the time when the dynamic feature point of the second sensor unit appears; the sequence flag is defined by a symbol function.

8. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 7, characterized in that, The specific output logic of the direction determination module (300) includes: When the time difference falls within the permitted range of the positive time difference and conforms to the positive order rule, it is marked as a positive match; When the time difference falls within the reverse time difference allowable range and conforms to the reverse order rule, it is marked as a reverse match; When the positive matching is satisfied for a consecutive preset number of rotation cycles, a positive rotation signal is output. When the reverse matching is satisfied for a consecutive preset number of cycle verifications (threshold number of rotation cycles), a reverse rotation signal is output.

9. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 1, characterized in that, The anti-interference mechanism includes: When the time difference exceeds the permissible range of the forward and reverse time difference, or when there is a conflict in the sequence rules, it is considered an invalid interference source; maintain the valid direction signal confirmed in the previous rotation cycle; accumulate and record conflict events in an independent counter, and only start the direction re-evaluation process when the number of consecutive conflicts reaches a preset threshold.

10. The digitally controlled tunneling and anchoring machine drum direction monitoring device according to claim 4, characterized in that, When there are no candidate feature points that meet the candidate conditions, the feature extraction module (200) switches to the drum angular velocity signal component and selects the zero-crossing point of the signal component that first changes from a negative value to a positive value within the period as the dynamic feature point.

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