Double-end chain tension force control system and control method for cross side dumping type scraper conveyor

Abstract

The invention belongs to the technical field of coal transportation of fully mechanized coal mining faces, and particularly relates to a double-end chain tension control system and method for a cross side dumping type scraper conveyor. Comprising a machine tail tensioning system, and the machine tail tensioning system is connected with a reversed loader at the tail of the scraper conveyor. The machine head tensioning system is connected to the head part of the scraper conveyor; the machine tail tensioning system and the machine head tensioning system jointly achieve double-end cooperative control of the chain transmission system on the scraper conveyor to adjust the tensioning force. The control system collects information of the machine tail tensioning system and the machine head tensioning system and controls the machine tail tensioning system and the machine head tensioning system. According to the telescopic machine head mechanism of the cross side dumping type scraper conveyor, the tensioning force can be rapidly adjusted through double-end cooperative control of a chain transmission system.

Description

Technical Field

[0001] The 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-discharging scraper conveyor. Background Art

[0002] The scraper conveyor is the "backbone" of the fully mechanized mining face. It is not only the key equipment for coal flow loading and transportation, but also the core equipment for guiding coal mining machines and traction hydraulic supports. When the coal is cut from the coal wall and transported to the head of the machine, the tension of the chain 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 avoid accidents such as chain stacking and chain breaking. At present, the tensioning system at the tail of the machine is mainly used to achieve dynamic compensation of the elastic deformation of the chain. However, the tail tensioning system has always had various drawbacks since its advent. The automatic control system cannot work normally after one year or even 2-3 months of use. Manual tensioning of the chain is required, but the manual tensioning effect is not as good as the automatic tensioning effect.

[0003] Research has found that during the process of conveying coal with a scraper conveyor, the tail tensioning system will cause the hydraulic cylinder to stretch too long in order to achieve dynamic compensation for the chain elongation, resulting in increased wear and structural deformation of the tail tensioning system, which will eventually cause the hydraulic cylinder to get stuck and unable to stretch normally, making the tensioning force automatic control system ineffective. When the tail cannot work normally, the machine can only be shut down for maintenance, which greatly affects the efficiency of coal mining.

[0004] The most advanced scraper conveyors are all cross-side unloading type. Therefore, based on this, the present invention has invented a double-end chain tension control system and method for cross-side unloading scraper conveyors to solve the above-mentioned tension control problem. The telescopic amount of the hydraulic cylinder is halved by tensioning both ends of the head and tail at the same time, which reduces the risk of structural deformation and ensures the normal telescopic extension of the hydraulic cylinder. In addition, when a single system of the head or tail fails, the other system can still work normally, reducing the downtime for maintenance. This invention is of great significance for ensuring the efficient coal transportation of scraper conveyors and extending their service life. Summary of the invention

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

[0006] The present invention adopts the following technical scheme: a double-end chain tensioning force control system of a cross side-discharging scraper conveyor, comprising: A tail tensioning system, the tail tensioning system is connected to the transfer machine at the tail of the scraper conveyor; A head tensioning system, wherein the head tensioning system 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 of the scraper conveyor to adjust the tensioning force; A control system collects information from a tail tensioning system and a nose tensioning system and controls both.

[0007] In some embodiments, the handpiece tensioning system comprises: A transition portion, the transition portion is cross-connected with the transfer machine; The moving part slides in the transport direction of the scraper conveyor to adjust the tension of the chain.

[0008] In some embodiments, the transition portion includes: A transition frame, the two 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 guide plate are fixed above the S coal dropping plate, wherein the guide plate is arc-shaped and the guide plate is vertically arranged in front of the coal guide plate to change the flow direction of the coal.

[0009] In some embodiments, the moving portion includes: Mobile racks; A telescopic middle trough assembly, which is mounted on a mobile frame and can slide on the mobile frame, and two sets of motor reducer assemblies are fixedly mounted on the mobile frame, and the two sets of motor reducer assemblies jointly drive a driving sprocket, and the driving sprocket is used to connect the scraper conveyor chain; A hydraulic assembly drives the telescopic middle trough assembly to slide on the moving frame along the transport direction of the scraper conveyor.

[0010] In some embodiments, the tail tensioning system includes a moving portion.

[0011] In some embodiments, the motor-reducer assembly includes a permanent magnet motor and a reducer, and the permanent magnet motor drives the reducer.

[0012] In some embodiments, the control system includes: A current sensor, wherein the current sensor is used to collect the input current of each permanent magnet motor; A torque sensor, wherein the 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 and contraction of the hydraulic component; The industrial computer input terminal is connected with 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, complete the processing and analysis of the control signal, and then control the action of the hydraulic cylinder to complete the automatic adjustment of the tensioning force.

[0013] A control method for a double-end chain tensioning force control system of a cross-side unloading scraper conveyor, comprising: S1: The industrial computer uses a deep learning algorithm to fuse the current signal I and the torque signal F 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 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, but the control system cannot reach the specified travel distance x / 2 due to a fault. The control system can determine that a fault has occurred at this 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 and stuckness 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 amount of the hydraulic cylinder of the tension control system with the 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. S5: If the tension force and telescopic stroke of one end do not reach the specified value, the control of this end is abandoned, and the tension force control is completely transferred to the other end to complete the tension force adjustment; S6: Send out an alarm to remind the staff to carry out planned downtime maintenance.

[0014] Step S1 includes: S11: Only the tail tensioning system is allowed to work, and the complete signal process of the current signal I and torque signal F of the scraper conveyor in n coal conveying cycles is collected, and 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 are manually calibrated; 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 of 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.

[0015] Step S2 includes: 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, the chain tension fluctuation is minimized, the hydraulic cylinder adjustment speed is the most stable, and the control quantity can be switched smoothly as reward values, and the hydraulic cylinder cannot reach the required tension force and the tension force fluctuation amplitude is large as penalty items. Deep reinforcement learning training is performed, and finally the trained model is deployed on the industrial computer; S23: In a real environment, when the tail tensioning system (1) and the nose tensioning system (2) work normally, under the control of deep reinforcement learning, the tail tensioning system (1) and the nose tensioning system (2) output F / 2 tension, both ends extend and retract at the same time, and monitor whether the extension and retraction 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.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention designs a retractable head mechanism of a cross-side unloading scraper conveyor, which can realize the rapid adjustment of the tension force by the coordinated control of both ends of the chain transmission system.

[0017] 2. The present invention adopts a method of tensioning both ends simultaneously, which can halve the telescopic stroke of the hydraulic cylinder, effectively reduce the risk of structural deformation, and increase the service life of the tensioning system.

[0018] 3. The tension control system of the present invention reduces the response time of adjusting the tension by half, thus improving the responsiveness of the system.

[0019] 4. The present invention can judge the fault, and when the tensioning system at one end fails and cannot work normally, the tensioning force control system at the other end can still carry out normal coal transportation, thereby improving the mining efficiency and reducing the unplanned downtime rate.

[0020] 5. The tension determination method based on deep learning of data fusion makes it less prone to errors; the control strategy based on deep reinforcement learning makes the control more intelligent and flexible. Overall, the accuracy and robustness of the system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Fig. 1 is a schematic diagram of the overall structure of the present invention; Figure 2 Schematic diagram of the head tensioning system of the present invention Figure 1 ; Figure 3 Schematic diagram of the head tensioning system of the present invention Figure 2 ; Figure 4 Schematic diagram of the head tensioning system of the present invention Figure 3 ; Figure 5 Schematic diagram of the head tensioning system of the present invention Figure 4 ; Figure 6 Schematic diagram of the structure of the moving part of the head tensioning system of the present invention Figure 1 ; Figure 7 Schematic diagram of the structure of the moving part of the head tensioning system of the present invention Figure 2 ; FIG8 is a schematic structural diagram of the telescopic part of the head tensioning system of the present invention; Fig. 9 is a cross-sectional view of the telescopic structure of the head tensioning system of the present invention; Fig. 10 is a schematic diagram of the cooperation between the upper and lower telescopic plates of the present invention; In the figure, 1- tail tensioning system, 2- head tensioning system, 21- motor reducer assembly, 22- connection 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- connection 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

[0022] 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, rather than 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.

[0023] like Figure 1 , 2 As shown, a double-end chain tensioning force control system of a cross side-discharging scraper conveyor comprises: A tail tensioning system 1, wherein the tail tensioning system 1 is connected to a transfer machine 26 at the tail of the scraper conveyor; A head tensioning system 2, wherein the head tensioning system 2 is connected to the head of the scraper conveyor; The tail tensioning system 1 and the head tensioning system 2 jointly realize the double-end coordinated control of the chain transmission system of the scraper conveyor to adjust the tensioning force; A control system, wherein the control system collects information of the tail tensioning system 1 and the nose tensioning system 2 and controls both of them.

[0024] Specifically, a scraper conveyor chain 291 is provided on the scraper conveyor, and scraper conveyor scrapers 292 are installed at intervals on the scraper conveyor chain 291, and the scraper conveyor scrapers 292 are used to promote the transportation of coal. The two ends of the scraper conveyor chain 291 are respectively installed on different driving sprockets 293, and the present application fixes the two driving sprockets 293 on the tail tensioning system 1 and the head tensioning system 2 respectively, and adjusts the positions of the two driving sprockets 293 of the tail tensioning system 1 and the head tensioning system 2 to adjust the tensioning force.

[0025] The head tensioning system 2 includes: A transition portion 41, wherein the transition portion 41 is cross-connected with the transfer machine 26; The moving part 42 slides in the transport direction of the scraper conveyor to adjust the tension of the chain.

[0026] Specifically, the transition part 41 is cross-lapped with the transfer machine 26 and connected by the connecting pin 27. The coal transported to the head of the machine is transferred to the transfer machine 26 by the scraper conveyor chain 291, the scraper conveyor scraper 292 and the driving sprocket 293, and then the coal is transported by the transfer machine chain 261, the transfer machine scraper 262 and the transfer machine sprocket 263 of the transfer machine 26. The transition part 41 is fixedly connected to the bottom plate 28, and the moving part 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.

[0027] The transition section 41 includes: A transition frame 412, both ends of which are connected to the middle trough of the scraper conveyor and the moving part 42; S coal dropping plate 411, wherein the S coal dropping plate 411 is fixed on the transition frame 412; The coal guide plate 24 and the guide plate 25 are fixed above the S coal dropping 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.

[0028] Specifically, one end of the transition part 41 is connected to the moving part 42 of the head tensioning system 2 to control the tensioning force, and the other end is connected to the middle groove to complete the transportation of coal. The S coal drop plate 411 is fixedly connected to the transition frame 412 by bolts to ensure that the coal is smoothly transferred from the scraper conveyor to the transfer machine 26. The coal guide plate 24 is fixedly connected to the guide plate 25, and both are located above the S coal drop plate 411. The guide plate 25 is arc-shaped, which can smoothly change the flow direction of coal and ensure the transportation of coal. The coal guide plate fixing plate 241 on the side of the transition part 41 and the crossbeam 242 above the transition part are fixedly connected to the coal guide plate 24 to complete the limit and fixation.

[0029] The moving part 42 includes: Mobile rack 57; A telescopic middle trough assembly, which is mounted on a moving frame 57 and can slide on the moving frame 57, and two sets of motor reducer assemblies 21 are fixedly mounted thereon, and the two sets of motor reducer assemblies 21 jointly drive a driving sprocket 293, and the driving sprocket 293 is used to connect a scraper conveyor chain 291; A hydraulic assembly drives the telescopic middle trough assembly to slide on the moving frame 57 along the transport direction of the scraper conveyor.

[0030] Specifically, Figure 5-10 As shown, the telescopic middle slot assembly includes: a wing plate 54, a side baffle plate 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, and 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 achieve 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 telescopic, 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.

[0031] 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 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 chamfers 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 the wing plate 54 and the side baffle 55.

[0032] The hydraulic assembly includes a hydraulic cylinder 33 and a hydraulic connection block 31; 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 moving frame 57, thereby realizing the transmission of power from the hydraulic cylinder 33 to the moving frame 57.

[0033] A slideway 281 is provided on the bottom plate 28 , and one slideway 281 is provided on each of the left and right sides of the moving frame 57 . The moving frame 57 can move forward and backward along the slideway 281 under the pushing action of the hydraulic cylinder 33 .

[0034] The tail tensioning system 1 includes a moving part 42 .

[0035] 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.

[0036] The motor reducer assembly 21 includes a permanent magnet motor and a reducer, and the permanent magnet motor drives the reducer. There are two groups in the head tensioning system and the tail tensioning system, which are located on the left and right sides of the tensioning system and are 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.

[0037] The control system includes: A current sensor, wherein the current sensor is used to collect the input current of each permanent magnet motor; A torque sensor, wherein the 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 oil; A hydraulic cylinder displacement sensor, which is used to monitor the pressure and expansion and contraction of the hydraulic component; The industrial computer input terminal is connected with 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.

[0038] There are four current sensors, hydraulic cylinder oil pressure sensors, torque sensors, and hydraulic cylinder displacement sensors. The current sensors are connected to the power lines of the permanent magnet motors to measure the input currents 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 end of the industrial computer is connected to the current sensor, hydraulic cylinder oil pressure sensor, and hydraulic cylinder displacement sensor to obtain the load signal of the chain drive system, complete the processing and analysis of the control signal, and then control the action of the hydraulic cylinder to complete the automatic adjustment of the tensioning force.

[0039] The current sensor can adopt Fengkong's Hall type current sensor, the oil pressure sensor can adopt Tianmu's NS-PI series pressure transmitter, the displacement sensor can adopt Germanjet's non-contact magnetostrictive displacement sensor, and the industrial computer can adopt Advantech's IPC series.

[0040] A control method for a double-end chain tensioning force control system of a cross-side unloading scraper conveyor, comprising: S1: The industrial computer sends the current signal I、 Torque signal F 扭 A deep learning algorithm is used to fuse data in real time to jointly determine the hydraulic cylinder pressure change corresponding to the current coal flow of the scraper conveyor F , displacement x ; 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.

[0041] 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 unloaded. F 0 、 Minimum displacement x 0 ; Maximum pressure when coal flow is maximum F 1 、 Maximum displacement x 1 .

[0042] The pressure is linearized 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 displacement change of the whole process x=k 2 × ( x 1 -x 0 ), k 2 ∈[0,1].

[0043] 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.

[0044] Convolutional neural networks are preferred for deep learning algorithms. Data is preprocessed, including normalization and standardization. 80% of the data is a training set and 20% is a test set. During the training process, the network parameters are optimized by the back propagation algorithm to minimize the loss function. The performance of the model is evaluated on the test set. With the maximum accuracy as the goal, the network structure, activation function, etc. are adjusted to finally determine the best mapping relationship. The network is then deployed on the industrial computer.

[0045] S2: Use deep reinforcement learning algorithm to perform intelligent collaborative control of the nose tensioning system and the tail tensioning system.

[0046] First, you need to train the algorithm. The training process of the algorithm is as follows: A mathematical model of the scraper conveyor 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.

[0047] The chain drive system is simplified based on the discrete element method and discretized into 2n mass blocks. The more n there are after discretization, the more accurate the model is, but the amount of calculation will also be greater. It is necessary to take multiple values ​​for verification and determination according to specific working conditions. Adjacent mass blocks are connected using the Kelvin-Voigt model, and the mathematical model is constructed and solved based on the Newton-Euler method. The mass block at the head sprocket is numbered 1, the mass block at the tail sprocket is numbered n+1, the upper chain mass blocks are 2~n, and the lower chain mass blocks are n+1~2n.

[0048] Mathematical model of the head tensioning system: In the formula, : The mass of the 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 chain mass block, i ∈[1,2n], N / m; : Damping coefficient of the chain mass block, 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; , the tension of chain mass block 1, N; The tension of the chain mass 2n, N.

[0049] Mathematical model of tail tensioning system: In the formula, : The 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 chain mass block, i∈[1,2n], N / m; : Damping coefficient of the chain mass block, 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 tail sprocket, N; : Head tension, N; , the tension of the chain mass n, N; The tension of chain mass n+1, N.

[0050] Mathematical model of chain drive system (2n-2 equations in total): In the formula, : 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 chain mass block, i ∈[1,2n], N / m; : Damping coefficient of the chain mass block, i ∈[1,2n], N·s / m.

[0051] During the tension adjustment training, the reward values ​​are as follows: the smallest chain tension fluctuation, the most stable hydraulic cylinder adjustment speed, and the smooth switching of the control amount; the reward values ​​are as follows: the hydraulic cylinder cannot reach the required tension (tension is F / 2 or F。 in F / 2 is the training tension when both ends can work normally. FThe tension value when only one end can work normally) and the fluctuation amplitude of the tension force are large as penalty items. The deep reinforcement learning algorithm is trained so that the algorithm can be continuously iterated and updated in the environment to achieve the best effect. The multi-agent deep deterministic policy gradient algorithm (MADDPG) is used for training first. Finally, the trained algorithm is deployed on the industrial computer.

[0052] 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 extend and retract at the same time, and monitor whether the extension and retraction 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.

[0053] S3: When the hydraulic components are stuck or the tensioning system structure is bent and deformed, the system cannot adjust the tension of the chain drive system normally. 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 and jamming 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 hydraulic cylinder extension and contraction of the tension control system at the faulty 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; S4: Send out an alarm to remind the staff to carry out planned downtime maintenance; S5: If the tension force and telescopic stroke of one end do not reach the specified value, the control of this end is abandoned, and the tension force control is completely transferred to the other end to complete the tension force adjustment; S6: Send out an alarm to remind the staff to carry out planned downtime maintenance.

[0054] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by 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 (1), the tail tensioning system (1) being connected to a transfer machine at the tail of the scraper conveyor; A head tensioning system (2), wherein the head tensioning system (2) is connected to the head of the scraper conveyor; The tail tensioning system (1) and the head tensioning system (2) jointly realize the double-end coordinated control of the chain transmission system of the scraper conveyor to adjust the tensioning force; A control system, wherein the control system collects information from a tail tensioning system (1) and a nose tensioning system (2) and controls both.

2. The double-end chain tension control system of the cross side-discharging scraper conveyor according to claim 1 is characterized in that: The machine head tensioning system (2) comprises: A transition portion (41), wherein the transition portion (41) and the transfer machine (26) are cross-connected and overlapped together; A moving part (42) slides in the transport direction of the scraper conveyor to adjust the tension of the chain.

3. The double-end chain tension control system of the cross side-discharging scraper conveyor according to claim 2 is characterized in that: The transition portion (41) comprises: A transition frame (412), wherein two ends of the transition frame (412) are respectively connected to the middle trough and the moving part (42) of the scraper conveyor; An S coal dropping plate (411), wherein the S coal dropping plate (411) is fixed on the transition frame (412); A coal guide plate (24) and a flow guide plate (25), wherein the coal guide plate (24) and the flow guide plate (25) are fixed above the S coal drop plate (411), wherein the flow 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.

4. The double-end chain tension control system of the cross side-discharging scraper conveyor according to claim 3 is characterized in that: The moving part (42) comprises: Mobile rack (57); A telescopic middle trough assembly, the telescopic middle trough assembly being mounted on a moving frame (57) and being able to slide on the moving frame (57), and having two sets of motor reducer assemblies (21) fixedly mounted thereon, the two sets of motor reducer assemblies (21) jointly driving a driving sprocket (293), the driving sprocket (293) being used to connect to a scraper conveyor chain (291); A hydraulic assembly drives the telescopic middle trough assembly to slide on the moving frame (57) along the transport direction of the scraper conveyor.

5. The double-end chain tension control system of the cross side-discharging scraper conveyor according to claim 4 is characterized in that: The tail tensioning system (1) comprises a moving part (42).

6. The double-end chain tension control system of the cross side-discharging scraper conveyor according to claim 5, characterized in that: The motor reducer assembly (21) comprises a permanent magnet motor and a reducer, and the permanent magnet motor drives the reducer.

7. The double-end chain tension control system of a cross side-discharging scraper conveyor according to claim 6, characterized in that: The control system comprises: A current sensor, wherein the current sensor is used to collect the input current of each permanent magnet motor; A torque sensor, wherein the 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 and contraction of the hydraulic component; The industrial computer input terminal is connected with 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, complete the processing and analysis of the control signal, and then control the action of the hydraulic cylinder to complete the automatic adjustment of the tensioning force.

8. A control method for a double-end chain tension control system of a cross side-discharging scraper conveyor as claimed in claim 7, characterized in that: include: S1: The industrial computer uses a deep learning algorithm to fuse the current signal I and the torque signal F 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 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, but the control system cannot reach the specified travel distance x / 2 due to a fault. The control system can determine that a fault has occurred at this 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 and stuckness 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 amount of the hydraulic cylinder of the tension control system with the 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. S5: If the tension force and telescopic stroke of one end do not reach the specified value, the control of this end is abandoned, and the tension force control is completely transferred to the other end to complete the tension force adjustment; S6: Send out an alarm to remind the staff to carry out planned downtime maintenance.

9. The control method of the double-end chain tensioning force control system of the cross side-discharging scraper conveyor according to claim 8, wherein the step S1 comprises: S11: Only the tail tensioning system is allowed to work, and the complete signal process of the current signal I and torque signal F of the scraper conveyor in n coal conveying cycles is collected, and 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 are manually calibrated; 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 of 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.

10. The control method of the double-end chain tensioning force control system of a cross side-discharging scraper conveyor according to claim 8, 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, the chain tension fluctuation is minimized, the hydraulic cylinder adjustment speed is the most stable, and the control quantity can be switched smoothly as reward values, and the hydraulic cylinder cannot reach the required tension force and the tension force fluctuation amplitude is large as penalty items. Deep reinforcement learning training is performed, and finally the trained model is deployed on the industrial computer; S23: In a real environment, when the tail tensioning system (1) and the nose tensioning system (2) work normally, under the control of deep reinforcement learning, the tail tensioning system (1) and the nose tensioning system (2) output F / 2 tension, both ends extend and retract at the same time, and monitor whether the extension and retraction 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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