Double-end chain tensioning force control system and control method for cross-side unloading scraper conveyor

Abstract

The present invention belongs to the technical field of coal transportation in fully mechanized mining working faces, specifically a double-end chain tensioning force control system and control method for a cross-side unloading scraper conveyor. It includes a tail tensioning system, which is connected to the transfer machine at the tail of the scraper conveyor; a head tensioning system, which is connected to the head of the scraper conveyor; the tail tensioning system and the head tensioning system jointly realize the double-end coordinated control of the chain transmission system on the scraper conveyor to adjust the tensioning force; a control system, which collects information from the tail tensioning system and the head tensioning system and controls both. The present invention designs a retractable head mechanism for a cross-side unloading scraper conveyor, which can realize the double-end coordinated control of the chain transmission system to quickly adjust the tensioning force.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal transportation in fully mechanized mining working faces, and specifically relates to a double-end chain tensioning force control system and a control method for a cross-side unloading scraper conveyor. Background Art

[0002] The scraper conveyor is the "backbone" of the fully mechanized mining face. It is not only a key piece of equipment for loading and transporting coal, but also the core equipment for guiding the shearer and traction hydraulic supports. As the coal is cut from the coal wall and transported toward the head of the machine, the chain tension needs to be adjusted in real time. Adjusting the scraper conveyor to the appropriate tension can effectively extend the service life of the chain and prevent accidents such as chain pile-up and chain breakage. Currently, the main method for dynamically compensating for the elastic deformation of the chain is to use a tensioning system at the tail of the machine. However, the tail tensioning system has been plagued by various drawbacks since its introduction. Automatic control systems often fail to function properly after a year or even two to three months of use, requiring manual tensioning of the chain. However, manual tensioning is not as effective as automatic tensioning.

[0003] Research has found that during the coal conveying process of a scraper conveyor, the tail tensioning system, in order to dynamically compensate for chain elongation, causes the hydraulic cylinder to extend and retract excessively. This leads to increased wear and structural deformation of the tail tensioning system, ultimately causing the hydraulic cylinder to become stuck and unable to retract properly, rendering the automatic tensioning control system ineffective. When the tail conveyor is not functioning properly, the machine must be shut down for maintenance, significantly impacting coal mining efficiency.

[0004] Currently, the most advanced scraper conveyors are all cross-side discharge type. Based on this, the present invention addresses the tension control issue mentioned above by inventing a double-end chain tension control system and method for cross-side discharge scraper conveyors. By simultaneously tensioning both the nose and tail ends, the hydraulic cylinder's extension and retraction capacity is halved, reducing the risk of structural deformation and ensuring the hydraulic cylinder's normal extension and retraction. Furthermore, if a single system in either the nose or tail fails, the other system can still operate normally, reducing downtime for maintenance. This invention is of great significance for ensuring efficient coal transportation and extending the service life of scraper conveyors. Summary of the Invention

[0005] In order to achieve effective control of chain tension, extend the service life of the scraper conveyor and realize efficient coal transportation, the present invention provides a double-end chain tension control system and control method for a cross-side unloading scraper conveyor.

[0006] The present invention adopts the following technical solution: a double-end chain tensioning force control system for a cross-side unloading scraper conveyor, comprising:

[0007] A tail tensioning system connected to the tail of the scraper conveyor;

[0008] A die head tensioning system, the die head tensioning system being connected to the head of the scraper conveyor;

[0009] The tail tensioning system and the head tensioning system jointly realize the double-end coordinated control of the scraper conveyor upper chain transmission system to adjust the tensioning force;

[0010] A control system collects information from the tail tensioning system and the nose tensioning system and controls both.

[0011] In some embodiments, the handpiece tensioning system comprises:

[0012] A transition portion, the transition portion being cross-connected with the transfer machine;

[0013] The moving part slides in the transport direction of the scraper conveyor to adjust the chain tension.

[0014] In some embodiments, the transition portion includes:

[0015] A transition frame, the ends of which are respectively connected to the middle trough and the moving part of the scraper conveyor;

[0016] S coal dropping plate, the S coal dropping plate is fixed on the transition frame;

[0017] The coal guide plate and the diversion plate are fixed above the S-shaped coal drop plate, wherein the diversion plate is arc-shaped and is vertically arranged in front of the coal guide plate to change the flow direction of the coal.

[0018] In some embodiments, the moving portion includes:

[0019] Mobile racks;

[0020] A telescopic middle trough assembly is mounted on a mobile frame and can slide on the mobile frame. Two sets of motor reducer assemblies are fixedly mounted on the mobile frame. The two sets of motor reducer assemblies jointly drive a driving sprocket, which is used to connect the scraper conveyor chain.

[0021] A hydraulic assembly drives the telescopic middle trough assembly to slide on the moving frame along the transport direction of the scraper conveyor.

[0022] In some embodiments, the tail tensioning system includes a moving portion.

[0023] In some embodiments, the motor-reducer assembly includes a permanent magnet motor and a reducer, and the permanent magnet motor drives the reducer.

[0024] In some embodiments, the control system includes:

[0025] A current sensor is used to collect the input current of each permanent magnet motor;

[0026] A torque sensor is used to collect the output torque of each reducer;

[0027] A hydraulic cylinder oil pressure sensor, which is used to collect the pressure of the hydraulic cylinder;

[0028] A hydraulic cylinder displacement sensor, which is used to monitor the pressure and expansion of the hydraulic component;

[0029] The industrial computer input terminal is connected to the current sensor, torque sensor, hydraulic cylinder oil pressure sensor, and hydraulic cylinder displacement sensor to obtain the load signal of the chain transmission system, and completes the processing and analysis of the control signal, thereby controlling the action of the hydraulic cylinder to complete the automatic adjustment of the tensioning force.

[0030] A control method for a double-end chain tensioning force control system of a cross-side unloading scraper conveyor, comprising:

[0031] S1: The industrial computer converts the current signal I and torque signal F 扭 A deep learning algorithm is used to fuse data in real time to jointly determine the hydraulic cylinder pressure change F and displacement x corresponding to the current coal flow of the scraper conveyor;

[0032] S2: Use deep reinforcement learning algorithm to perform intelligent collaborative control of the nose tensioning system and the tail tensioning system;

[0033] S3: When the hydraulic component is stuck or the structure of the tensioning system is bent and deformed, the system cannot normally adjust the tension of the chain drive system. It can be found that the tension of the head or tail tensioning control system has reached the set value F / 2, but the control system cannot reach the specified travel distance x / 2 due to the fault. The control system can then determine that a fault has occurred at that end and the hydraulic cylinder cannot be normally extended or retracted. At this time, the output force of the hydraulic cylinder is partially offset by the bending deformation, sticking, etc. of the structural parts, so that the output force of the hydraulic cylinder cannot be fully transmitted to the chain drive system. If the output force of this end is F / 2 and the displacement is x', the extension and retraction amount of the hydraulic cylinder of the tensioning control system at the faulty end is transferred to the tensioning control system at the other end that can work normally. The output displacement of the other end is x / 2+(x / 2-x'), so that the coal transportation work can proceed normally.

[0034] S5: If the tension and telescopic stroke at one end do not reach the specified values, the control of that end is abandoned and all tension control is transferred to the other end to complete the tension adjustment;

[0035] S6: Send out an alarm to remind the staff to carry out planned maintenance.

[0036] Step S1 includes:

[0037] S11: Only the tail tensioning system is operated to collect the current signal I and torque signal F of the scraper conveyor in n coal conveying cycles. 扭 The complete signal process is manually calibrated to obtain the minimum pressure F0 and minimum displacement x0 of the hydraulic cylinder when no-load; the maximum pressure F1 and maximum displacement x1 when the coal flow rate is maximum;

[0038] S12: Linearize the pressure value, that is, the pressure change during the whole process F=k 1 × ( F 1 -F 0 ), k 1∈[0,1]; the change in displacement during the whole process x=k 2 × ( x 1 -x 0 ), k 2∈[0,1];

[0039] S13: Preprocess the collected data and train the neural network, and deploy the trained neural network on the industrial computer.

[0040] Step S2 includes:

[0041] S21: Establish mathematical models of the head tensioning system, tail tensioning system, and chain transmission system of the scraper conveyor;

[0042] S22: During the tension adjustment training process, rewards are given for minimizing chain tension fluctuations, maintaining the smoothest hydraulic cylinder adjustment speed, and smoothly switching the control variable. Penalties are for failing to achieve the required tension or large fluctuations in tension. Deep reinforcement learning training is performed, and the trained model is deployed on an industrial computer.

[0043] S23: In a real environment, when the tail tensioning system and the nose tensioning system are working normally, the tail tensioning system and the nose tensioning system output respectively under the control of deep reinforcement learning F / 2 tension, both ends stretch at the same time, and monitor whether the stretching stroke at both ends is x / 2. If the extension and retraction distance is reached, it means that the tensioning system is working normally and the tensioning force is adjusted to the appropriate size.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. This invention designs a retractable head mechanism for a cross-side discharge scraper conveyor, which can realize the rapid adjustment of the tension force by coordinated control of both ends of the chain drive system.

[0046] 2. The present invention adopts the method of tensioning at both ends simultaneously, which can halve the telescopic stroke of the hydraulic cylinder, effectively reducing the risk of structural deformation and extending the service life of the tensioning system.

[0047] 3. The tension control system of the present invention reduces the response time of tension adjustment by half, thereby improving the responsiveness of the system.

[0048] 4. The present invention can judge faults, and when the tensioning system at one end fails to work properly, the tensioning control system at the other end can still carry out normal coal transportation, thereby improving mining efficiency and reducing unplanned downtime rate.

[0049] 5. A method for determining tension using deep learning based on data fusion makes it less prone to error; a control strategy based on deep reinforcement learning makes control more intelligent and flexible. Overall, this improves the accuracy and robustness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 is a schematic diagram of the overall structure of the present invention;

[0051] Figure 2 Schematic diagram of the head tensioning system of the present invention Figure 1 ;

[0052] Figure 3 Schematic diagram of the head tensioning system structure of the present invention Figure 2 ;

[0053] Figure 4 Schematic diagram of the head tensioning system of the present invention Figure 3 ;

[0054] Figure 5 Schematic diagram of the head tensioning system structure of the present invention Figure 4 ;

[0055] Figure 6 Schematic diagram of the movable structure of the head tensioning system of the present invention Figure 1 ;

[0056] Figure 7 Schematic diagram of the movable part structure of the head tensioning system of the present invention Figure 2 ;

[0057] FIG8 is a schematic structural diagram of the telescopic portion of the head tensioning system of the present invention;

[0058] FIG9 is a cross-sectional view of the telescopic structure of the head tensioning system of the present invention;

[0059] Figure 10 Schematic diagram of the upper and lower telescopic plates of the present invention;

[0060] In the figure, 1- tail tensioning system, 2- head tensioning system, 21- motor reducer assembly, 22- connecting pad, 231- upper protective cover, 232- side protective cover, 24- coal guide plate, 241- coal guide plate fixing plate, 242- crossbeam, 25- guide plate, 26- transfer machine, 261- transfer machine chain, 262- transfer machine scraper, 263- transfer machine sprocket, 27- connecting pin, 28- bottom plate, 281- slideway, 291- scraper conveyor chain, 292- scraper conveyor Scraper, 293-driving sprocket, 294-sprocket shaft, 31-hydraulic cylinder connecting block, 33-hydraulic cylinder, 41-transition part, 42-moving part, 411-S coal dropping plate, 412-transition frame, 51-lower telescopic plate, 511-lower telescopic plate support plate, 512-guide protrusion, 52-upper telescopic plate, 521-upper telescopic plate fixing frame, 522-fixed frame support plate, 53-tongue plate, 54-wing plate, 55-side baffle, 56-upper pressure plate, 57-moving frame, 58-derailleur. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0062] like Figure 1 、 2 As shown, a double-end chain tensioning force control system for a cross-side unloading scraper conveyor includes:

[0063] The tail tensioning system 1 is connected to the tail of the scraper conveyor;

[0064] A head tensioning system 2, wherein the head tensioning system 2 is connected to the head of the scraper conveyor;

[0065] The tail tensioning system 1 and the head tensioning system 2 jointly realize the double-end coordinated control of the scraper conveyor upper chain transmission system to adjust the tensioning force;

[0066] A control system collects information from the tail tensioning system 1 and the nose tensioning system 2 and controls both of them.

[0067] Specifically, the scraper conveyor is provided with a scraper conveyor chain 291, and scraper conveyor blades 292 are installed at intervals on the scraper conveyor chain 291. The scraper conveyor blades 292 are used to promote the transportation of coal. The ends of the scraper conveyor chain 291 are respectively mounted on different driving sprockets 293. In this application, the two driving sprockets 293 are respectively fixed to the tail tensioning system 1 and the head tensioning system 2. By adjusting the positions of the two driving sprockets 293 of the tail tensioning system 1 and the head tensioning system 2, the tensioning force can be adjusted.

[0068] The head tensioning system 2 includes:

[0069] A transition portion 41, wherein the transition portion 41 is cross-connected with the transfer machine 26;

[0070] The moving part 42 slides in the transport direction of the scraper conveyor to adjust the chain tension.

[0071] Specifically, the transition portion 41 cross-overlaps the transfer conveyor 26 and is connected via a connecting pin 27. The coal delivered to the head of the conveyor is transferred to the transfer conveyor 26 by the scraper conveyor chain 291, scraper conveyor blades 292, and driving sprocket 293. The coal is then transported by the transfer conveyor chain 261, transfer conveyor blades 262, and transfer conveyor sprocket 263 of the transfer conveyor 26. The transition portion 41 is fixedly connected to the bottom plate 28, and the movable portion 42 is located on the upper side of the bottom plate 28 and can slide on the upper side of the bottom plate 28 to adjust the chain tension.

[0072] The transition portion 41 includes:

[0073] A transition frame 412, the ends of which are respectively connected to the middle trough of the scraper conveyor and the moving part 42;

[0074] S coal dropping plate 411, said S coal dropping plate 411 being fixed on the transition frame 412;

[0075] The coal guide plate 24 and the guide plate 25 are fixed above the S coal drop plate 411, wherein the guide plate 25 is arc-shaped and is vertically arranged in front of the coal guide plate 24 to change the flow direction of the coal.

[0076] Specifically, one end of the transition section 41 is connected to the movable portion 42 of the head tensioning system 2 to control the tensioning force, and the other end is connected to the central trough to complete the coal transportation. The S-shaped coal drop plate 411 is fixedly connected to the transition frame 412 via bolts, ensuring smooth transfer of coal from the scraper conveyor to the transfer machine 26. The coal guide plate 24 is fixedly connected to the guide plate 25, both located above the S-shaped coal drop plate 411. The guide plate 25 is curved and can smoothly change the flow direction of the coal, ensuring coal transportation. The coal guide plate fixing plate 241 on the side of the transition section 41 and the crossbeam 242 above the transition section are fixedly connected to the coal guide plate 24 to achieve positioning and fixation.

[0077] The moving part 42 includes:

[0078] Mobile rack 57;

[0079] A telescopic middle trough assembly, which is mounted on a mobile frame 57 and can slide on the mobile frame 57. Two sets of motor reducer assemblies 21 are fixedly mounted on the mobile frame 57. The two sets of motor reducer assemblies 21 jointly drive a driving sprocket 293. The driving sprocket 293 is used to connect to the scraper conveyor chain 291;

[0080] A hydraulic assembly drives the telescopic middle trough assembly to slide on the moving frame 57 along the transport direction of the scraper conveyor.

[0081] Specifically, if Figure 5-10 As shown, the telescopic middle slot assembly includes: a wing plate 54, a side baffle 55, a lower telescopic plate 51, a lower telescopic plate support plate 511, an upper telescopic plate 52, an upper telescopic plate fixing frame 521, a fixing frame support plate 522 and a tongue plate 53. The lower telescopic plate 51 is overlapped on the upper side of the transition frame 412 and fixedly connected thereto. At the same time, it is fixedly connected to the transition frame 412 through the lower telescopic plate support plate 511 on the lower side of the lower telescopic plate 51. The upper telescopic plate 52 is located on the upper side of the lower telescopic plate 51 and cross-lapped. The upper telescopic plate 52 can slide on the upper surface of the lower telescopic plate 51 to realize the main telescopic action. The lower telescopic plate 51 has two guide protrusions 512, which are plugged into the upper telescopic plate 52 to provide a guiding function for the upper telescopic plate 52 when it is telescoped, and the upper surface of the guide protrusion 512 is in the same plane as the upper surface of the upper telescopic plate 52, and the upper and lower telescopic plates are provided with chamfers.

[0082] The side of the upper telescopic plate 52 is fixedly connected to the movable frame 57, and the lower side is connected to the upper telescopic plate 52 fixing frame. The upper telescopic plate fixing frame 521 has a fixing frame support plate 522 and is fixedly connected to the movable frame 57. The chain derailleur 58 is fixedly connected to the upper telescopic plate fixing frame 521 by bolts. The tongue plate 53 is fixedly connected to the upper telescopic plate 52 by bolts and is located on the upper surface of the upper telescopic plate 52. The tongue plate 53 is a consumable part and can be updated and replaced. There are two wing plates 54 located on both sides of the transition frame 412 and fixedly connected to the transition frame 412. The wing plate 54 is designed with a chamfer to realize the reversal of the scraper conveyor. The side baffle 55 is fixedly connected to the wing plate 54. The upper pressure plate 56 is fixedly connected to the movable frame 57 and pressed on top of the wing plate 54 and the side baffle 55.

[0083] The hydraulic assembly includes a hydraulic cylinder 33 and a hydraulic connection block 31;

[0084] The hydraulic assembly is located on the lower side of the connecting pad frame 22, one on each side. One end of the hydraulic cylinder 33 is rotatably connected to the base plate 28 through a connecting pin, and the other end is rotatably connected to the hydraulic connecting block 31. The hydraulic connecting block 31 is rotatably connected to the movable frame 57, thereby realizing the transmission of power from the hydraulic cylinder 33 to the movable frame 57.

[0085] A slideway 281 is provided on the bottom plate 28 , with one slideway 281 on each side of the movable frame 57 . The movable frame 57 can move forward and backward along the slideway 281 under the pushing action of the hydraulic cylinder 33 .

[0086] The tail tensioning system 1 includes a moving portion 42 .

[0087] Specifically, the structure of the tail tensioning system 1 is the same as the structure of the moving part 42 in the head tensioning system 2 , and the tail tensioning system 1 is arranged at the tail of the scraper conveyor.

[0088] The motor-reducer assembly 21 includes a permanent magnet motor and a reducer, which is driven by the permanent magnet motor. There are two sets of motor-reducer assembly 21 in each of the head tensioning system and tail tensioning system, located on the left and right sides of the tensioning system, fixedly connected to one side of the connecting pad frame, and the other side of the connecting pad frame is fixedly connected to the moving frame.

[0089] The control system includes:

[0090] A current sensor is used to collect the input current of each permanent magnet motor;

[0091] A torque sensor is used to collect the output torque of each reducer;

[0092] A hydraulic cylinder oil pressure sensor, which is used to collect the pressure of the hydraulic cylinder oil;

[0093] A hydraulic cylinder displacement sensor, which is used to monitor the pressure and expansion of the hydraulic component;

[0094] The industrial computer input terminal is connected to the current sensor, the hydraulic cylinder oil pressure sensor, and the hydraulic cylinder displacement sensor to obtain the load signal of the chain transmission system, and completes the processing and analysis of the control signal, thereby controlling the action of the hydraulic cylinder to complete the automatic adjustment of the tensioning force.

[0095] There are four current sensors, four hydraulic cylinder oil pressure sensors, four torque sensors, and four hydraulic cylinder displacement sensors. The current sensors are connected to the power lines of the permanent magnet motors to measure the input current of the four motors. The hydraulic cylinder oil pressure sensors and hydraulic cylinder displacement sensors are connected to the hydraulic cylinders to monitor the pressure and extension of the hydraulic cylinders. The input terminal of the industrial computer is connected to the current sensors, hydraulic cylinder oil pressure sensors, and hydraulic cylinder displacement sensors to obtain the load signal of the chain drive system, complete control signal processing and analysis, and then control the movement of the hydraulic cylinder to automatically adjust the tension.

[0096] The current sensor can use Fengkong's Hall type current sensor, the oil pressure sensor can use Tianmu's NS-PI series pressure transmitter, the displacement sensor can use Germanjet's non-contact magnetostrictive displacement sensor, and the industrial computer can use Advantech's IPC series.

[0097] A control method for a double-end chain tensioning force control system of a cross-side unloading scraper conveyor, comprising:

[0098] S1: The industrial computer sends the current signal I、 Torque signal F 扭 Use deep learning algorithms to integrate data in real time to jointly determine the hydraulic cylinder pressure changes corresponding to the current coal flow of the scraper conveyor F , displacement x ;

[0099] According to the actual working process, the coal flow is proportional to the current and torque, so the two signals can reflect the size of the coal flow.

[0100] First, only the tail tensioning system is allowed to work, and the scraper conveyor is collected. n Current signal in a coal conveying cycle I , torque signal F 扭 The complete signal process. And manually calibrate the minimum pressure of the hydraulic cylinder when it is no-load. F 0 、 Minimum displacement x 0 ; Maximum pressure when coal flow is maximum F 1 、 Maximum displacement x1 .

[0101] Linearize the pressure to obtain the value, that is, the pressure change during the whole process F=k 1 × ( F 1 -F 0 ), k 1∈[0,1]; the change in displacement during the whole process x=k 2 × ( x 1 -x 0 ), k 2∈[0,1].

[0102] In the present invention n =3, the current signal I , torque signal F 扭 , total pressure change F Take the average value. I , torque signal F 扭 As input, the total pressure change F、 Total displacement change x As output, deep learning is performed to complete the mapping of the signal.

[0103] Convolutional neural networks are preferred deep learning algorithms. Data preprocessing, including normalization and standardization, is performed. 80% of the data is used as a training set, and 20% as a test set. During training, network parameters are optimized using the backpropagation algorithm to minimize the loss function. Model performance is evaluated on the test set. With the goal of maximizing accuracy, adjustments are made to the network structure, activation function, and other factors to ultimately determine the optimal mapping relationship. The network is then deployed on an industrial computer.

[0104] S2: Use deep reinforcement learning algorithm to perform intelligent collaborative control of the nose tensioning system and the tail tensioning system.

[0105] First, you need to train the algorithm. The training process of the algorithm is as follows:

[0106] A mathematical model of the scraper conveyor's head tensioning system, tail tensioning system, and chain drive system is established. This model can accurately reflect the physical process of tensioning force adjustment, and a deep reinforcement learning training environment is built based on this mathematical model.

[0107] The chain drive system is simplified using the discrete element method and discretized into 2n masses. A larger number of discretizations (n) results in a more accurate model, but this also increases the computational complexity, requiring multiple validations based on specific operating conditions. Adjacent masses are connected using the Kelvin-Voigt model, and the mathematical model is constructed and solved using the Newton-Euler method. The mass at the nose sprocket is numbered 1, the mass at the tail sprocket is numbered n+1, the upper chain masses are numbered 2 to n, and the lower chain masses are numbered n+1 to 2n.

[0108] Mathematical model of the head tensioning system:

[0109]

[0110] Where, : Mass of the machine head tensioning system, kg; : radius of the nose sprocket, m; : angular acceleration of the nose sprocket, rad / s 2 ; : angular velocity of the nose sprocket, rad / s; : The rotation angle of the head sprocket, rad; : stiffness coefficient of the chain mass, i ∈[1,2n], N / m; : Damping coefficient of the chain mass, i ∈[1,2n], N·s / m; : the speed of the chain mass, j ∈[1,2n], m / s; : displacement of the chain mass, j ∈[1,2n], m / s; , input torque of the nose sprocket, N·m; : rotational resistance of the nose sprocket, N; : Head tension, N; , tension of chain mass 1, N; The tension in the chain mass 2n, N.

[0111] Mathematical model of tail tensioning system:

[0112]

[0113] Where, : mass of the tail tensioning system, kg; : radius of the tail sprocket, m; : angular acceleration of the tail sprocket, rad / s 2 ; : angular velocity of the tail sprocket, rad / s; : The rotation angle of the tail sprocket, rad; : stiffness coefficient of the chain mass, i ∈[1,2n], N / m; : Damping coefficient of the chain mass, i ∈[1,2n], N·s / m; : the speed of the chain mass, j ∈[1,2n], m / s; : displacement of the chain mass, j ∈[1,2n], m / s; , input torque of the tail sprocket, N·m; : rotational resistance of the tail sprocket, N; : Head tension, N; , the tension of the chain mass n, N; The tension in chain mass n+1, N.

[0114] Mathematical model of chain drive system (2n-2 equations in total):

[0115]

[0116] Where, : The mass of the chain mass block, y ∈[2,n]∪[n+1,2n],kg; : acceleration of the chain mass, j ∈[1,2n], m / s; : the speed of the chain mass, j ∈[1,2n], m / s; : displacement of the chain mass, j ∈[1,2n], m / s; : radius of the nose sprocket, m; : The rotation angle of the head sprocket, rad; : angular velocity of the nose sprocket, rad / s; : The running resistance of the chain mass block, y ∈[2,n]∪[n+1,2n],N; : stiffness coefficient of the chain mass, i ∈[1,2n], N / m; : Damping coefficient of the chain mass, i ∈[1,2n], N·s / m.

[0117] During the tension adjustment training, the reward value is when the chain tension fluctuation is the smallest, the hydraulic cylinder adjustment speed is the most stable, and the control amount can be switched smoothly. The reward value is when the hydraulic cylinder cannot reach the required tension (tension isF / 2 or F。 in F / 2 is the training tension when both ends can work normally. F The tension value is the value when only one end is functioning properly), and large fluctuations in tension are penalized. A deep reinforcement learning algorithm is trained, allowing it to continuously iterate and update within the environment to achieve optimal results. The Multi-Agent Deep Deterministic Policy Gradient (MADDPG) algorithm is preferred for training. Finally, the trained algorithm is deployed on an industrial computer.

[0118] In a real environment, when the nose and tail systems are working normally, the nose tensioning system and the tail tensioning system output respectively under the control of deep reinforcement learning. F / 2 tension, both ends stretch at the same time, and monitor whether the stretching stroke at both ends is x / 2. If the extension and retraction distance is reached, it means that the tensioning system is working normally and the tensioning force is adjusted to the appropriate size.

[0119] S3: When the hydraulic components are stuck or the structure of the tensioning system is bent and deformed, the system cannot normally adjust the tension of the chain drive system. It can be found that the tension of the head or tail tension control system has reached the set value. F / 2 However, due to a fault in the control system, the telescopic stroke cannot reach the specified stroke distance. x / 2, the control system can determine that a fault has occurred at this end and the hydraulic cylinder cannot be extended or retracted normally. At this time, the output force of the hydraulic cylinder is partially offset by the bending deformation, jamming and other reasons of the structural parts, so that the output force of the hydraulic cylinder cannot be fully transmitted to the chain drive system. If the output force at this end is F / 2, the displacement is x’ The extension and contraction of the hydraulic cylinder of the tension control system with fault at this end is transferred to the tension control system at the other end that can work normally. The output displacement of the other end is x / 2+( x / 2- x’ ), so that the coal transportation work can proceed normally;

[0120] S4: Send out an alarm to remind the staff to carry out planned downtime maintenance;

[0121] S5: If the tension and telescopic stroke at one end do not reach the specified values, the control of that end is abandoned and all tension control is transferred to the other end to complete the tension adjustment;

[0122] S6: Send out an alarm to remind the staff to carry out planned maintenance.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double-end chain tension control system for a cross-side unloading scraper conveyor, characterized in that: include: A tail tensioning system connected to the tail of the scraper conveyor; A die head tensioning system, the die head tensioning system being connected to the head of the scraper conveyor; The tail tensioning system and the head tensioning system jointly realize the double-end coordinated control of the scraper conveyor upper chain transmission system to adjust the tensioning force; A control system that collects information from the tail tensioning system and the nose tensioning system and controls both; The head tensioning system includes: A transition portion, the transition portion being cross-connected with the transfer machine; A moving part that slides in the transport direction of the scraper conveyor to adjust the tension of the chain; The moving part includes: Mobile racks; A telescopic middle trough assembly is mounted on a mobile frame and can slide on the mobile frame. Two sets of motor reducer assemblies are fixedly mounted on the mobile frame. The two sets of motor reducer assemblies jointly drive a driving sprocket, which is used to connect the scraper conveyor chain. A hydraulic assembly that drives the telescopic middle trough assembly to slide on the moving frame along the transport direction of the scraper conveyor; The tail tensioning system includes a moving portion; The motor reducer assembly includes a permanent magnet motor and a reducer, and the permanent magnet motor drives the reducer; The control system includes: A current sensor is used to collect the input current of each permanent magnet motor; A torque sensor is used to collect the output torque of each reducer; A hydraulic cylinder oil pressure sensor, which is used to collect the pressure of the hydraulic cylinder; A hydraulic cylinder displacement sensor, which is used to monitor the pressure and expansion of the hydraulic component; An industrial computer, wherein the input terminal of the industrial computer is connected to a current sensor, a torque sensor, a hydraulic cylinder oil pressure sensor, and a hydraulic cylinder displacement sensor to obtain a load signal of the chain drive system, and completes processing and analysis of the control signal, thereby controlling the action of the hydraulic cylinder to automatically adjust the tensioning force; Control methods, including: S1: The industrial computer converts the current signal I and torque signal F 扭 A deep learning algorithm is used to fuse data in real time to jointly determine the hydraulic cylinder pressure change F and displacement x corresponding to the current coal flow of the scraper conveyor; S2: Use deep reinforcement learning algorithm to perform intelligent collaborative control of the nose tensioning system and the tail tensioning system; S3: When the hydraulic component is stuck or the structure of the tensioning system is bent and deformed, the control system cannot normally adjust the tension of the chain drive system. It can be found that the tension of the head or tail tensioning system has reached the set value F / 2, but the control system cannot reach the specified travel distance x / 2 due to a fault. The control system can then determine that a fault has occurred at one end of the head or tail, and the hydraulic cylinder cannot be normally extended or retracted. At this time, the output force of the hydraulic cylinder is partially offset by the bending deformation and sticking of the structural parts, so that the output force of the hydraulic cylinder cannot be fully transmitted to the chain drive system. If the output force of this end is F / 2 and the displacement is x', the extension and retraction amount of the hydraulic cylinder of the tensioning system at this end is transferred to the tensioning system at the other end that can work normally. The output displacement of the other end is x / 2+(x / 2-x'), so that the coal transportation work can proceed normally. S5: If the tension and telescopic stroke at one end do not reach the specified values, the control of that end is abandoned and all tension control is transferred to the other end to complete the tension adjustment; S6: Send out an alarm to remind the staff to carry out planned maintenance.

2. The double-end chain tension control system of a cross-side unloading scraper conveyor according to claim 1 is characterized in that: The transition portion includes: A transition frame, the ends of which are respectively connected to the middle trough and the moving part of the scraper conveyor; S coal dropping plate, the S coal dropping plate is fixed on the transition frame; The coal guide plate and the diversion plate are fixed above the S-shaped coal drop plate, wherein the diversion plate is arc-shaped and is vertically arranged in front of the coal guide plate to change the flow direction of the coal.

3. The double-end chain tensioning force control system of a cross-side discharge scraper conveyor according to claim 1, wherein step S1 comprises: S11: Only the tail tensioning system is operated to collect the current signal I and torque signal F of the scraper conveyor in n coal conveying cycles. 扭 The complete signal process is manually calibrated to obtain the minimum pressure F0 and minimum displacement x0 of the hydraulic cylinder when no-load; the maximum pressure F1 and maximum displacement x1 when the coal flow rate is maximum; S12: Linearize the pressure value, that is, the pressure change during the whole process F=k 1 × ( F 1 -F 0 ), k 1∈[0,1]; The displacement change during the whole process x=k 2 × ( x 1 -x 0 ), k 2∈[0,1]; S13: Preprocess the collected data and train the neural network, and deploy the trained neural network on the industrial computer.

4. The double-end chain tensioning force control system of a cross-side-discharge scraper conveyor according to claim 1, wherein step S2 comprises: S21: Establish mathematical models of the head tensioning system, tail tensioning system, and chain transmission system of the scraper conveyor; S22: During the tension adjustment training process, rewards are given for minimizing chain tension fluctuations, maintaining the smoothest hydraulic cylinder adjustment speed, and smoothly switching the control variable. Penalties are for failing to achieve the required tension or large fluctuations in tension. Deep reinforcement learning training is performed, and the trained model is deployed on an industrial computer. S23: In a real environment, when the tail tensioning system and the nose tensioning system are working normally, the tail tensioning system and the nose tensioning system output respectively under the control of deep reinforcement learning F / 2 tension, both ends stretch at the same time, and monitor whether the stretching stroke at both ends is x / 2. If the extension and retraction distance is reached, it means that the tensioning system is working normally and the tensioning force is adjusted to the appropriate size.

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