A wheel bucket excavator cutting process stability intelligent adjustment system and method

Abstract

The application discloses a kind of wheel bucket excavator cutting process stability intelligent adjustment system and method, belong to the technical field of wheel bucket excavator, including host computer, multichannel data acquisition system, control module and acceleration sensor.The application uses, host computer judges that cantilever produces resonance, host computer controls the action of first hydraulic telescopic rod, first hydraulic telescopic rod drives wheel bucket assembly to move left and right, so that the depth of wheel bucket assembly cutting into rock wall changes, host computer judges again whether cantilever produces resonance, if not resonance side host computer controls first telescopic rod to stop by control module;If resonance, side host computer continues to adjust the depth of wheel bucket assembly cutting into rock wall, until cantilever stops resonance, reach the purpose of active avoidance resonance zone, improve the life of bucket tooth, cantilever weld fatigue crack initiation cycle is extended;Realize continuous stable operation under high and cold environment;Compared with passive damping scheme, reduce the quality of complete machine, and then reduce energy consumption.

Description

Technical Field

[0001] This invention belongs to the technical field of bucket wheel excavators, and particularly relates to an intelligent adjustment system and method for the stability of the cutting process of a bucket wheel excavator. Background Technology

[0002] Bucket wheel excavators, also known as bucket wheel excavators, are multi-bucket excavators that use multiple buckets mounted on the bucket wheel assembly at the front of the boom for continuous digging. They are used for large-scale earthmoving, stripping and mining in ore fields, and loading and unloading operations in large material yards. They have high productivity, large digging force, and can directly excavate relatively hard soil. In large-scale construction, water conservancy projects, and mines, they are often used in conjunction with transportation equipment to form continuous operation lines. Larger bucket wheel excavators have great digging force and are commonly used in mining.

[0003] Currently, the open-pit mines in high-altitude and cold environments have low temperatures, high rock brittleness, and high hardness. When the bucket wheel assembly cuts through the rock wall, the rock wall generates a violent reaction force on the bucket, which can easily induce structural vibrations in the bucket wheel assembly-cantilever system.

[0004] When the excitation frequency approaches the system's natural frequency, structural resonance will occur, leading to: (1) a significant decrease in cutting efficiency; (2) a sharp reduction in the fatigue life of key components (bucket teeth, cantilever, bearing housing, etc.); and (3) even the risk of the entire machine overturning.

[0005] Existing technologies mostly focus on structural reinforcement or passive vibration reduction (such as adding dampers and thickening the cantilever), which cannot actively adjust the resonant frequency according to real-time working conditions. They cannot meet the requirements for stable operation in high-altitude open-pit mine environments with low temperatures, high rock brittleness, and high hardness. Ultimately, this leads to a series of problems such as high energy consumption of bucket wheel excavators, severe vibration of the cantilever and cab, and poor equipment adaptability and operating comfort. Summary of the Invention

[0006] The purpose of this invention is to provide an intelligent adjustment system and method for the stability of a bucket wheel excavator during the cutting process. This system can actively adjust the vibration frequency of the boom according to the real-time working conditions of the bucket wheel excavator, thereby avoiding boom resonance. It effectively solves a series of problems in the prior art, such as high energy consumption, severe vibration of the boom and cab, and poor equipment adaptability and operating comfort caused by structural resonance in the bucket wheel excavator.

[0007] The present invention adopts the following technical solution: an intelligent adjustment system for the stability of a bucket wheel excavator during the cutting process, comprising a support frame, a cantilever hinged on the support frame, a bucket wheel assembly disposed at the end of the cantilever, and a traveling mechanism rotatably connected to the lower end face of the support frame; a rotating shaft fixedly disposed on the rear side of the bucket wheel assembly, a bearing seat rotatably connected to the outer surface of the rotating shaft, and the bearing seat slidably connected to the cantilever along the length direction of the cantilever; a first hydraulic telescopic rod fixedly disposed on the cantilever, and the output shaft of the first hydraulic telescopic rod fixedly disposed to the bearing seat; It also includes a host computer, a multi-channel data acquisition system, a control module, and an acceleration sensor; Accelerometers are placed at multiple measuring points along the length of the cantilever at set intervals to acquire vibration data. The multi-channel data acquisition system is used to collect vibration data from accelerometer tests and perform filtering. The host computer determines whether the cantilever is resonating based on the data processed by the multi-channel data acquisition system. The host computer determines that the cantilever is resonating and sends a signal to the control module. The control module controls the first hydraulic telescopic rod to move, which drives the bucket wheel assembly to move left and right, causing the depth of the bucket wheel assembly cutting into the rock wall to change. The host computer then determines whether the cantilever is resonating based on the data processed by the multi-channel data acquisition system. If there is no resonance, the host computer controls the first telescopic rod to stop through the control module. If there is resonance, the host computer continues to adjust the depth of the bucket wheel assembly cutting into the rock wall until the cantilever stops resonating.

[0008] Furthermore, the host computer is connected to the multi-channel data acquisition system and has built-in modal identification and resonance discrimination algorithms. Modal identification identifies the working modes of the cantilever based on the vibration data of the multi-channel data acquisition system, and the resonance discrimination algorithm determines whether the cantilever resonates based on the working mode identification.

[0009] Furthermore, the modal identification is based on the vibration data to extract the dominant frequency f, which is the working mode of the cantilever.

[0010] Furthermore, the resonance discrimination algorithm is pre-defined with a cantilever resonance bandwidth [fL, fH].

[0011] Furthermore, the resonance discrimination algorithm compares the main frequency f with the resonance bandwidth [fL, fH]. If f falls within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has structural resonance; if f does not fall within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has not structural resonance.

[0012] Furthermore, the control module includes two control lines. One control line is connected to the first hydraulic telescopic rod to control its movement, and the other control line is connected to the motor via a frequency converter. The output shaft and rotation shaft of the motor are fixedly connected. The host computer adjusts the motor speed through the control module and the frequency converter.

[0013] Furthermore, a torque sensor is installed on the rotating shaft to test the torque value of the rotating shaft; the host computer outputs instructions to the control module to control the action of the first hydraulic telescopic rod or to control the motor speed through the frequency converter based on the coupling relationship between the current vibration main frequency f and the torque T, so that the current main frequency f avoids the structural resonance bandwidth [fL, fH].

[0014] Furthermore, the coupling relationship between the vibration dominant frequency f and the torque T is as follows: a) When the torque T signal decreases and the vibration dominant frequency f increases, reducing the speed of the bucket wheel assembly or increasing the cutting depth can increase the torque T and decrease the dominant frequency f; b) When the torque T signal increases and the vibration dominant frequency f decreases, increasing the speed of the bucket wheel assembly or decreasing the cutting depth can decrease the torque T and increase the dominant frequency f.

[0015] Furthermore, the coupling relationship between the dominant vibration frequency f and the torque T is: T = (9550Pp) / (60f).

[0016] A method for adjusting the stability of a bucket wheel excavator during the cutting process, comprising the intelligent adjustment system for the stability of a bucket wheel excavator during the cutting process as described above, characterized in that: S1, During the cutting operation, the accelerometer collects vibration data from multiple measuring points on the cantilever in real time; S2, the multi-channel data acquisition system collects vibration data from the accelerometer and performs filtering processing; S3, Modal identification in the host computer extracts the main frequency f based on vibration data; S4, the resonance discrimination algorithm in the host computer compares the main frequency f with the resonance bandwidth [fL,fH]. If f falls within the preset resonance bandwidth [fL,fH], it is determined that the cantilever has structural resonance; if f does not fall within the preset resonance bandwidth [fL,fH], it is determined that the cantilever has not structural resonance. S5. The host computer, based on the coupling relationship between the vibration main frequency f and the torque T: a) when the torque T signal decreases and the vibration main frequency f increases, reducing the speed of the bucket wheel assembly or increasing the cutting depth can increase the torque T and decrease the main frequency f; b) when the torque T signal increases and the vibration main frequency f decreases, increasing the speed of the bucket wheel assembly or decreasing the cutting depth can decrease the torque T and increase the main frequency f. S6, the host computer continuously monitors until f leaves the resonant bandwidth [fL,fH].

[0017] I. This invention, through the configuration of a cantilever, bucket wheel assembly, host computer, multi-channel data acquisition system, control module, and acceleration sensor, allows the host computer to detect resonance in the cantilever during operation. The host computer then sends a signal to the control module, which controls the first hydraulic telescopic rod to move. This first hydraulic telescopic rod moves the bucket wheel assembly left and right, changing the depth at which the bucket wheel assembly cuts into the rock wall. The host computer then uses data processed by the multi-channel data acquisition system to determine if the cantilever is resonating. If no resonance occurs, the host computer controls the first telescopic rod to stop via the control module. If resonance occurs, the host computer continues to adjust the depth at which the bucket wheel assembly cuts into the rock wall until the cantilever stops resonating, thus actively avoiding the resonance zone, improving the lifespan of the bucket teeth, and extending the fatigue crack initiation period of the cantilever weld. It also enables continuous and stable operation in cold environments and, compared to passive vibration reduction schemes, reduces the overall machine weight, thereby lowering energy consumption.

[0018] II. This invention sets up a built-in modal identification and resonance discrimination algorithm in the host computer. Modal identification is based on vibration data from a multi-channel data acquisition system to identify the working modes of the cantilever and extract the dominant frequency f. The resonance discrimination algorithm compares the dominant frequency f with the resonance bandwidth [fL, fH]. If f falls within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has structural resonance; if f does not fall within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has not structural resonance. This achieves the purpose of real-time monitoring of the working modes of the cantilever to determine whether resonance has occurred. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a front view structural diagram of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the support in this invention; Figure 4 This is a schematic diagram of the three-dimensional cantilever structure in this invention; Figure 5 This is a three-dimensional structural diagram of the bucket wheel assembly in this invention; Figure 6 This is a three-dimensional structural diagram of the rotating shaft in this invention; Figure 7 This is a schematic diagram showing the electrical connections of the host computer, multi-channel data acquisition system, control module, frequency converter, and acceleration sensor in this invention. Figure 8 This is a schematic diagram showing the electrical connection of the host computer, multi-channel data acquisition system, and acceleration sensor in this invention.

[0020] In the diagram, 1. Bucket wheel assembly; 2. Bucket; 3. Cantilever; 4. Motor; 5. First hydraulic telescopic rod; 6. Support frame; 8. Walking mechanism; 9. Multi-channel data acquisition system; 10. Host computer; 11. Frequency converter; 12. Control module; 13. Accelerometer; 14. Material handling arm; 15. Rotating shaft; 16. Bearing seat; 17. Base plate; 18. Fixed block; 19. Mobile chassis; 20. Track; 21. Drive wheel; 22. Gear disc; 23. Tie rod; 24. Hinge block; 25. Rotating block; 26. Second hydraulic telescopic rod. Detailed Implementation

[0021] Please see Figure 1-8 The present invention will now be described in detail with reference to the accompanying drawings and embodiments: The intelligent stability adjustment system for the cutting process of the bucket wheel excavator described in this invention includes a support 6, a cantilever 3 hinged to the support 6, a material-collecting arm 14 rotatably connected to the upper end face of the support 6, the right end of the cantilever 3 being above the left end of the material-collecting arm 14, a bucket wheel assembly 1 being provided at the left end of the cantilever 3, and buckets 2 being evenly fixed along the circumference of the bucket wheel assembly 1. A traveling mechanism 8 is rotatably connected to the lower end face of the support 6. During normal use, the traveling mechanism 8 drives the support 6, the material-collecting arm 14, and the cantilever 3 to move. When they reach the designated position, the bucket wheel assembly 1 rotates, causing the buckets 2 to rotate. The buckets 2 cut the rock wall, and the cut material enters the buckets 2 and follows the rotation of the buckets 2. When bucket 2 rotates to the top, the material inside bucket 2 falls downward onto cantilever 3. Both cantilever 3 and the material-retrieving arm 14 are equipped with belt conveyors along their length. The belt conveyors transport the material to the right end of cantilever 3 and onto the material-retrieving arm 14. The belt conveyor on the material-retrieving arm 14 then transports the material to the right end of the material-retrieving arm 14, completing the unloading. The material-retrieving arm 14 can rotate on the support 6 with its left end as the center, so that the material-retrieving arm 14 and cantilever 3 form a set angle. The purpose is to allow the right end of the material-retrieving arm 14 to rotate flexibly to adjust the unloading position. The cantilever 3 can also rotate up and down to adjust the pitch angle so that the bucket wheel assembly 1 can cut into the rock wall at a suitable angle.

[0022] In this embodiment, a rotating shaft 15 is fixedly installed on the rear side of the bucket wheel assembly 1. A bearing seat 16 is rotatably connected to the outer surface of the rotating shaft 15. The bearing seat 16 is slidably connected to the cantilever 3 along the length direction of the cantilever 3. The motor 4 is fixedly installed with the bearing seat 16. The output shaft of the motor 4 is fixedly installed with the rotating shaft 15. The motor 4 drives the rotating shaft 15 to rotate, and the rotating shaft 15 drives the bucket wheel assembly 1 to rotate. A first hydraulic telescopic rod 5 is fixedly installed on the cantilever 3. The output shaft of the first hydraulic telescopic rod 5 is fixedly installed with the bearing seat 16. The extension and retraction of the first hydraulic telescopic rod 5 drives the bearing seat 16 to move left and right. The bearing seat 16 drives the bucket wheel assembly 1 to move left and right through the rotating shaft 15, thereby increasing or decreasing the cutting depth of the bucket wheel assembly 1 when cutting the rock wall.

[0023] In this embodiment, there are two bearing seats 16 arranged on the front and rear sides of the cantilever 3 along the front-rear direction. The upper end face of the base plate 17 is fixedly arranged with the lower end face of each bearing seat 16. The lower end face of the base plate 17 is slidably connected to the cantilever 3 in the left-right direction. A fixing block 18 is fixedly arranged at the output end of the first hydraulic telescopic rod 5. The lower end face of the fixing block 18 is fixedly arranged with the base plate 17. The extension and retraction of the first hydraulic telescopic rod 5 drives the base plate 17 to move left and right through the fixing block 18. The base plate 17 drives the two bearing seats 16 to move left and right. The bearing seats 16 drive the wheel bucket assembly 1 to move left and right through the rotating shaft 15, so as to adjust the distance between the wheel bucket assembly 1 and the rock wall in the left-right direction, thereby achieving the purpose of adjusting the cutting depth of the rock wall by the wheel bucket assembly 1 when cutting the rock wall.

[0024] In this embodiment, a guide rail is fixedly provided on the lower end face of the base plate 17, and a guide groove adapted to the guide rail is provided on the upper end face of the cantilever 3. The base plate 17 is slidably connected to the cantilever 3 through the guide rail and the guide groove; the guide rail and the guide groove are not shown in the figure.

[0025] In this embodiment, the walking mechanism 8 includes a mobile chassis 19 and tracks 20. The front and rear sides of the mobile chassis 19 are rotatably connected to transmission wheels 21. The two transmission wheels 21 on the front side are connected to the corresponding tracks 20, and the two transmission wheels 21 on the rear side are connected to the corresponding tracks 20. The power device drives the transmission wheels 21 to rotate, and the rotation of the transmission wheels 21 drives the tracks 20 to move. The tracks 20 can then drive the mobile chassis 19 to move, thus achieving the purpose of movement.

[0026] In this embodiment, a toothed disk 22 is rotatably connected to the upper end face of the mobile chassis 19. The upper end face of the toothed disk 22 is fixedly set with the material picking arm 14. By driving the toothed disk 22 to rotate, the purpose of driving the material picking arm 14 to rotate can be achieved. During the unloading stage, the right end of the material picking arm 14 changes its spatial position by rotation, thereby conveniently adjusting the unloading landing point.

[0027] Given that the rotating support structure of the material-retrieving arm 14 is located on the left side, its right side is suspended, which could lead to potential stability issues during operation. To address this, in this embodiment, four tie rods 23 are hinged to the upper surface of the material-retrieving arm 14. The top ends of the two tie rods 23 on the right side are fixed to each other and hinged to a hinge block 24. The top ends of the two tie rods 23 on the left side are also fixed to the hinge block 24. A rotating block 25 is rotatably connected to the support 6. A second hydraulic telescopic rod 26 is hinged to the outer surface of the rotating block 25, and the output end of the second hydraulic telescopic rod 26 is hinged to the hinge block 24. The support 6 exerts a pulling force on the material-retrieving arm 14 through the rotating block 25, the second hydraulic telescopic rod 26, the hinge block 24, and the tie rods 23, thereby increasing the stability of the material-retrieving arm 14 without affecting its rotation. When the material-retrieving arm 14 rotates, the connecting rod, the hinge block 24, and the second hydraulic telescopic rod 26 all rotate around the axis of the rotating block 25.

[0028] In this embodiment, the system includes a host computer 10, a multi-channel data acquisition system 9, a control module 12, and an acceleration sensor 13. Accelerometer 13 is set at multiple measuring points along the length of cantilever 3 at a set interval to acquire vibration data; The multi-channel data acquisition system 9 is used to collect vibration data tested by the accelerometer 13 and perform filtering processing; The host computer 10 determines whether the cantilever 3 resonates based on the data processed by the multi-channel data acquisition system 9. The host computer 10 determines that the cantilever 3 is resonating. The host computer 10 sends a signal to the control module 12, and the control module 12 controls the first hydraulic telescopic rod 5 to move. The first hydraulic telescopic rod 5 drives the bucket wheel assembly 1 to move left and right, so that the depth of the bucket wheel assembly 1 cutting into the rock wall changes. The host computer 10 again determines whether the cantilever 3 is resonating based on the data processed by the multi-channel data acquisition system 9. If there is no resonance, the host computer 10 controls the first telescopic rod to stop through the control module 12; if there is resonance, the host computer 10 continues to adjust the depth of the bucket wheel assembly 1 cutting into the rock wall until the cantilever 3 stops resonating.

[0029] Furthermore, the host computer 10 is connected to the multi-channel data acquisition system 9. The host computer 10 has built-in modal identification and resonance discrimination algorithms. Modal identification is based on the vibration data of the multi-channel data acquisition system 9 to identify the working mode of the cantilever 3. The resonance discrimination algorithm is based on the working mode identification to determine whether the cantilever 3 resonates.

[0030] In this embodiment, modal identification extracts the dominant frequency f based on vibration data, where f is the working mode of cantilever 3. Specifically, the vibration frequency is calculated as vibration period S (i.e., the number of peaks and troughs) within a set time D, where S is the vibration period and D is the time. Modal identification analysis employs either random subspace identification or frequency domain decomposition. Random subspace identification primarily targets stochastic systems that respond freely to environmental excitations. These systems typically lack controllable input signals, and their output response is mainly determined by the system's internal dynamic characteristics and external random excitations. Frequency domain decomposition, based on the principle of Fourier transform, decomposes the time-domain signal into signals of different frequencies, thus obtaining the frequency-domain signal. In the frequency domain, the signal can be decomposed into components of different frequencies, each corresponding to a different frequency, amplitude, and phase.

[0031] In this embodiment, the resonance discrimination algorithm is preset with the resonance bandwidth [fL, fH] of the cantilever 3.

[0032] In this embodiment, the method for obtaining the resonant bandwidth [fL, fH] of the cantilever 3 is as follows: The experimental measurement methods mainly include the resonance method, frequency response function measurement, and hammer impact method.

[0033] The resonance method involves adjusting the excitation frequency (e.g., using sound waves or a vibration table) and monitoring the object's response amplitude. The frequency corresponding to the maximum amplitude is the natural frequency, and the resonance bandwidth is determined by the half-power point. Frequency response function measurement involves exciting an object with an exciter and measuring the response with an accelerometer. The frequency response function of the input force and output response is calculated. The natural frequency corresponds to the peak value or phase abrupt change point of the amplitude-frequency curve, and the bandwidth can be calculated using the half-power bandwidth method. The hammer-impact method uses a hammer equipped with a force sensor to strike an object, generating a wideband excitation. The spectrum of the response signal is analyzed using Fourier transform; the peak frequency is the natural frequency, and the bandwidth is estimated based on the half-power point. The theoretical calculation method is based on a single-degree-of-freedom system model or finite element analysis. For a simplified model, the natural frequency can be calculated by the formula (f=frac{1}{2\pi}\sqrt{frac{k}{m}}), where k is the stiffness and m is the mass; the resonant bandwidth [fL,fH] is calculated by the frequency difference corresponding to the half-power point (1 / √2 of the peak amplitude), i.e. (Deltaf=fH-fL).

[0034] It should be noted that an object may have multiple natural frequencies (corresponding to different modes), and the natural frequencies depend on stiffness, mass distribution and boundary conditions. External interference should be avoided during measurement, and multiple experiments should be conducted to obtain the average.

[0035] In this embodiment, the resonance discrimination algorithm compares the main frequency f with the resonance bandwidth [fL, fH]. If f falls within the preset resonance bandwidth [fL, fH], it is determined that the cantilever 3 has structural resonance; if f does not fall within the preset resonance bandwidth [fL, fH], it is determined that the cantilever 3 has not structural resonance.

[0036] The host computer 10 determines that the cantilever 3 is resonating. The host computer 10 sends a signal to the control module 12. The control module 12 controls the first hydraulic telescopic rod 5 to move. The first hydraulic telescopic rod 5 drives the bucket wheel assembly 1 to move left and right, causing the depth of the bucket wheel assembly 1 cutting into the rock wall to change. The host computer 10 compares the main frequency f with the resonance bandwidth [fL, fH] through the resonance discrimination algorithm. If f falls into the preset resonance bandwidth [fL, fH], it is determined that the cantilever 3 has structural resonance. The host computer 10 continues to adjust the depth of the bucket wheel assembly 1 cutting into the rock wall until the cantilever 3 stops resonating. If f does not fall into the preset resonance bandwidth [fL, fH], it is determined that the cantilever 3 has not structural resonance. The host computer 10 controls the first telescopic rod to stop through the control module 12.

[0037] In this embodiment, the control module 12 includes two control lines. One control line is connected to the first hydraulic telescopic rod 5 to control the movement of the first hydraulic telescopic rod 5. The other control line is connected to the motor 4 through the frequency converter 11. The host computer 10 adjusts the speed of the motor 4 through the control module 12 and the frequency converter 11, and then adjusts the speed of the bucket wheel assembly 1 through the rotating shaft 15.

[0038] In this embodiment, a torque sensor (not shown in the figure) is installed on the rotating shaft 15. The torque sensor measures the torque value of the rotating shaft 15.

[0039] In this embodiment, the host computer 10 outputs a command to the control module 12 to control the action of the first hydraulic telescopic rod 5 or controls the speed of the motor 4 through the frequency converter 11 according to the coupling relationship between the current vibration main frequency f and the torque T, so that the current main frequency f avoids the structural resonance bandwidth [fL, fH].

[0040] In this embodiment, the coupling relationship between the vibration dominant frequency f and the torque T is as follows: a) When the torque T signal decreases and the vibration dominant frequency f increases, reducing the rotational speed of the bucket wheel assembly 1 or increasing the cutting depth can increase the torque T and decrease the dominant frequency f; b) When the torque T signal increases and the vibration dominant frequency f decreases, increasing the rotational speed of the bucket wheel assembly 1 or decreasing the cutting depth can decrease the torque T and increase the dominant frequency f.

[0041] In state a, when the torque T signal decreases and the vibration frequency f increases, it means that the wheel bucket assembly 1 rotates at a high speed and vibrates a lot. That is, the torque T decreases and the frequency f increases. Therefore, reducing the speed of the wheel bucket assembly 1 or increasing the cutting depth can increase the torque T and decrease the frequency f. In state b, when the torque T signal increases and the vibration frequency f decreases, it means that the wheel bucket assembly 1 rotates at a low speed and vibrates little. That is, the torque T increases and the frequency f decreases. Therefore, increasing the speed of the wheel bucket assembly 1 or decreasing the cutting depth can decrease the torque T and increase the frequency f.

[0042] In this embodiment, the coupling relationship between the dominant vibration frequency f and the torque T is: T = (9550Pp) / (60f).

[0043] For AC motor 4, there exists the formula T = 9550(P) / (n), where T is the torque (in Nm), P is the power of motor 4 (in kW), and n is the speed of motor 4 (in r / min). The speed of motor 4 is n = (60 F) / (p), where F is the power supply frequency (in Hz), and P is the number of pole pairs of motor 4. Substituting n = (60 F) / (p) into T = 9550(P) / (n), we get T = (9550Pp) / (60 F). Assuming that the power P and the number of pole pairs p of motor 4 remain constant, this formula shows that when the power P and the number of pole pairs p of motor 4 are constant, the torque T is inversely proportional to the frequency F, that is, the higher the frequency F, the smaller the torque T; the lower the frequency F, the larger the torque T. According to the formula T = 9550(P) / (n), it can be seen that the torque T is inversely proportional to the speed n.

[0044] Here, the power supply frequency F is directly proportional to the rotational speed n, and the rotational speed n is directly proportional to the dominant vibration frequency f of the cantilever 3. Therefore, T = (9550Pp) / (60F), where F ∝ f, specifically, T = (9550Pp) / (60f). Thus, the torque T is inversely proportional to the dominant frequency f; that is, the higher the dominant frequency f, the smaller the torque T; and the lower the dominant frequency f, the larger the torque T.

[0045] An adjustment method based on an intelligent stability adjustment system for the cutting process of a bucket wheel excavator includes: S1, during the cutting operation, an acceleration sensor 13 collects vibration data from multiple measuring points on the cantilever 3 in real time; S2, the multi-channel data acquisition system 9 collects vibration data from the accelerometer 13 and performs filtering processing; S3, Modal identification within the host computer 10 extracts the main frequency f based on vibration data; S4, the resonance discrimination algorithm in the host computer 10 compares the main frequency f with the resonance bandwidth [fL,fH]. If f falls into the preset resonance bandwidth [fL,fH], it is determined that the cantilever 3 has structural resonance; if f does not fall into the preset resonance bandwidth [fL,fH], it is determined that the cantilever 3 has not structural resonance. S5, the coupling relationship between the main vibration frequency f and the torque T of the host computer 10: a, when the torque T signal decreases and the main vibration frequency f increases, reducing the speed of the bucket wheel assembly 1 or increasing the cutting depth can increase the torque T and decrease the main frequency f; b, when the torque T signal increases and the main vibration frequency f decreases, increasing the speed of the bucket wheel assembly 1 or decreasing the cutting depth can decrease the torque T and increase the main frequency f. S6, the host computer 10 continuously monitors until f leaves the resonant bandwidth [fL,fH].

Claims

1. A smart stability adjustment system for the cutting process of a bucket wheel excavator, characterized in that: The system includes a support frame, a cantilever hinged to the support frame, a bucket wheel assembly at the end of the cantilever, and a traveling mechanism rotatably connected to the lower end face of the support frame; a rotating shaft is fixedly mounted on the rear side of the bucket wheel assembly, and a bearing seat is rotatably connected to the outer surface of the rotating shaft, with the bearing seat slidably connected to the cantilever along the length of the cantilever; a first hydraulic telescopic rod is fixedly mounted on the cantilever, and the output shaft of the first hydraulic telescopic rod is fixedly mounted to the bearing seat. It also includes a host computer, a multi-channel data acquisition system, a control module, and an acceleration sensor; Accelerometers are placed at multiple measuring points along the length of the cantilever at set intervals to acquire vibration data. The multi-channel data acquisition system is used to collect vibration data from accelerometer tests and perform filtering. The host computer determines whether the cantilever is resonating based on the data processed by the multi-channel data acquisition system. The host computer determines that the cantilever is resonating and sends a signal to the control module. The control module controls the first hydraulic telescopic rod to move. The first hydraulic telescopic rod drives the bucket wheel assembly to move left and right, causing the depth of the bucket wheel assembly cutting into the rock wall to change. The host computer then determines whether the cantilever is resonating based on the data processed by the multi-channel data acquisition system. If there is no resonance, the host computer controls the first telescopic rod to stop through the control module. If resonance occurs, the side-mounted control unit continues to adjust the depth of the bucket wheel assembly cutting into the rock wall until the cantilever stops resonating.

2. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 1, characterized in that: The host computer is connected to a multi-channel data acquisition system and has built-in modal identification and resonance discrimination algorithms. Modal identification identifies the working modes of the cantilever based on the vibration data of the multi-channel data acquisition system, and the resonance discrimination algorithm determines whether the cantilever resonates based on the working mode identification.

3. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 2, characterized in that: The modal identification described above is based on the extraction of the dominant frequency f from vibration data, where the dominant frequency f is the working mode of the cantilever.

4. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 3, characterized in that: The resonance discrimination algorithm pre-sets the resonance bandwidth [fL, fH] for each cantilever.

5. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 4, characterized in that: The resonance discrimination algorithm compares the dominant frequency f with the resonance bandwidth [fL, fH]. If f falls within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has structural resonance; if f does not fall within the preset resonance bandwidth [fL, fH], it is determined that the cantilever has not structural resonance.

6. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 5, characterized in that: The control module includes two control lines. One control line is connected to the first hydraulic telescopic rod to control its movement, and the other control line is connected to the motor through a frequency converter. The output shaft and the rotation shaft of the motor are fixedly set. The host computer adjusts the motor speed through the control module and the frequency converter.

7. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 6, characterized in that: A torque sensor is installed on the rotating shaft to test the torque value of the rotating shaft. The host computer outputs a command to the control module to control the action of the first hydraulic telescopic rod or controls the motor speed through the frequency converter based on the coupling relationship between the current vibration frequency f and the torque T, so that the current frequency f avoids the structural resonance bandwidth [fL, fH].

8. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 7, characterized in that: The coupling relationship between the dominant vibration frequency f and the torque T is as follows: a) When the torque T signal decreases and the dominant vibration frequency f increases, reducing the speed of the bucket wheel assembly or increasing the cutting depth can increase the torque T and decrease the dominant frequency f; b) When the torque T signal increases and the dominant vibration frequency f decreases, increasing the speed of the bucket wheel assembly or decreasing the cutting depth can decrease the torque T and increase the dominant frequency f.

9. The intelligent stability adjustment system for the cutting process of a bucket wheel excavator according to claim 8, characterized in that: The coupling relationship between the dominant vibration frequency f and the torque T is: T = (9550Pp) / (60f).

10. A method for adjusting the stability of a bucket wheel excavator during the cutting process based on an intelligent adjustment system, comprising the intelligent adjustment system for the stability of a bucket wheel excavator during the cutting process as described in any one of claims 1-9, characterized in that: S1, During the cutting operation, the accelerometer collects vibration data from multiple measuring points on the cantilever in real time; S2, the multi-channel data acquisition system collects vibration data from the accelerometer and performs filtering processing; S3, Modal identification in the host computer extracts the main frequency f based on vibration data; S4, the resonance discrimination algorithm in the host computer compares the main frequency f with the resonance bandwidth [fL,fH]. If f falls within the preset resonance bandwidth [fL,fH], it is determined that the cantilever has structural resonance; if f does not fall within the preset resonance bandwidth [fL,fH], it is determined that the cantilever has not structural resonance. S5. The host computer, based on the coupling relationship between the vibration main frequency f and the torque T: a) when the torque T signal decreases and the vibration main frequency f increases, reducing the speed of the bucket wheel assembly or increasing the cutting depth can increase the torque T and decrease the main frequency f; b) when the torque T signal increases and the vibration main frequency f decreases, increasing the speed of the bucket wheel assembly or decreasing the cutting depth can decrease the torque T and increase the main frequency f. S6, the host computer continuously monitors until f leaves the resonant bandwidth [fL,fH].

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