Distributed multi-agent chain transmission control system and control method for scraper conveyor

Abstract

The present invention discloses a distributed multi-agent chain transmission control system and control method for a scraper conveyor. The transmission control system includes a head intelligent agent, an intermediate intelligent agent, a tail intelligent agent and a coal conveying section. The head intelligent agent and the tail intelligent agent only provide the driving force of the motor, eliminating the chain tensioning system at the tail and saving space in the tunnel. The intermediate intelligent agent includes a motor drive system and a torsional tensioning system. The intermediate intelligent agent can provide the motor driving force. The chain tensioning force control system of the intermediate intelligent agent is designed based on torsional and translational motion, which can realize the tensioning force control of the single-sided or double-end chain of the intermediate intelligent agent. The control method proposed in the present invention is a hierarchical control method based on multi-agent reinforcement learning, which combines motor power balance with tensioning force control to ensure the stable coal conveying operation of the scraper conveyor.

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 distributed multi-intelligent chain transmission control system for a scraper conveyor and a control method thereof. Background Art

[0002] The scraper conveyor is the only coal transportation equipment in the fully mechanized mining face. The existing scraper conveyor uses double-end motors at the head and tail to drive the chain and uses a hydraulic system at the tail to adjust the chain tension.

[0003] Faced with the development trend of longer haul distances and higher mining heights, the amount of coal transported by scraper conveyors will increase significantly. This puts higher demands on the scraper conveyor's motor drive and tensioning devices during coal transportation. The vibration generated during coal transportation affects the power balance of the head and tail motors and the stable operation of the tail tensioning system, which can easily cause scraper conveyor failures and reduce coal mining efficiency. As the amount of coal transported increases, the power demand for the motor increases. If only the head and tail motors are used to provide driving force, the motors will become too large, increasing the motor's footprint in the roadway, forcing the mining of larger roadways. However, the mining cost of roadways is high, thus increasing the cost of coal mining.

[0004] Patent publication number CN114394377A discloses a multi-point drive scraper conveyor synchronization control system, comprising a primary motor and a multi-stage motor group disposed between two primary motors. The primary motor and each motor in the multi-stage motor group are each provided with a sprocket and a piezoelectric vibrator. The piezoelectric vibrator, the primary motor, and each motor in the multi-stage motor group are all connected to a computer. When the scraper conveyor is operating, the piezoelectric vibrator sends a current intensity signal to the computer, which determines the operating status of the scraper conveyor based on the current intensity signal and controls the operation of the primary motor and each motor in the multi-stage motor group. The multi-point drive scraper conveyor synchronization control system can achieve graded start and stop of the scraper conveyor, reduce the overall tension on the scraper chain, and improve the reliability of the system operation process.

[0005] Patent publication number CN116142695A discloses a long-distance, non-uniform-strength, three-drive, energy-efficient scraper conveyor system. The system comprises a nose sprocket I, a nose sprocket II, a tail sprocket, a nose drive motor I, a nose drive motor II, a tail drive motor, a scraper chain, a nose torque sensor I, a tail torque sensor, and a motor control module. The motor control module analyzes and processes collected torque signals to intelligently control the operating state of nose drive motor II under varying transport conditions. This allows the scraper conveyor to efficiently and energy-efficiently transport materials in all operating modes, reducing power loss.

[0006] Patent publication number CN114394377A discloses a multi-point drive scraper conveyor synchronization control system, comprising a primary motor and a multi-stage motor group disposed between two primary motors. The primary motor and each motor in the multi-stage motor group are each provided with a sprocket and a piezoelectric vibrator. The piezoelectric vibrator, the primary motor, and each motor in the multi-stage motor group are all connected to a computer. When the scraper conveyor is operating, the piezoelectric vibrator sends a current intensity signal to the computer, which determines the operating status of the scraper conveyor based on the current intensity signal and controls the operation of the primary motor and each motor in the multi-stage motor group. The multi-point drive scraper conveyor synchronization control system can achieve graded start and stop of the scraper conveyor, reduce the overall tension on the scraper chain, and improve the reliability of the system operation process.

[0007] The above existing technologies have solved the problems of long-distance scraper conveyors to a certain extent, but generally speaking, there are still some shortcomings: the amount of coal transported by the scraper conveyor continues to increase, and the elastic elongation of the chain will also continue to increase. When the hydraulic tensioning system at the tail of the machine is used to supplement the elastic elongation of the chain, it will occupy the space of the tunnel and increase the mining cost of the tunnel. The power balance control of the motor and the tension control of the chain are coupled and influence each other, and jointly determine the stable operation of the coal transportation process. In the face of long-distance scraper conveyors, an appropriate method is needed to ensure the normal operation of the two systems. The above existing technologies do not take into account the problem of elastic elongation of the chain, and the coupling relationship between the power balance control of the motor and the tension control of the chain. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a distributed multi-intelligent chain transmission control system and control method for a scraper conveyor. In a distributed manner, the driving power required by the scraper conveyor is shared among multiple motors, and the hydraulic tensioning device at the tail of the machine is eliminated. A multi-point hydraulic tensioning strategy is adopted to ensure stable coal transportation of the scraper conveyor.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a distributed multi-agent chain transmission system for a scraper conveyor, comprising:

[0010] The head intelligent body is arranged at the head of the scraper conveyor, and includes a head permanent magnet motor, which is installed on the head frame and drives the sprocket;

[0011] The tail intelligent body is arranged at the tail of the scraper conveyor and includes a tail permanent magnet motor installed on the tail frame, and the tail permanent magnet motor drives the sprocket;

[0012] The coal conveying section consists of several middle chutes;

[0013] The intermediate intelligent body includes a motor drive system and a torsion tensioning system; two sets of intermediate intelligent bodies are respectively arranged at the middle and two ends of the scraper conveyor;

[0014] The motor drive system includes a middle permanent magnet motor, which drives the sprocket to rotate;

[0015] The torsional tensioning system is used to control the tensioning force, and includes a frame, a turntable, a torsional hydraulic motor, a tensioning wheel and a tensioning wheel shaft; the frame is fixedly connected to the middle transition frame and the middle groove respectively, the turntable is rotatably connected to the frame, the torsional hydraulic motor housing is fixedly connected to the frame, and the torsional hydraulic motor output shaft is fixedly connected to the turntable to drive the turntable to rotate; the tensioning wheel shaft is installed on the turntables on both sides, and the tensioning wheel is installed on the tensioning wheel shaft.

[0016] Furthermore, in the intermediate intelligent body, the motor drive system further comprises an intermediate transition frame, a first movable middle plate, a second movable middle plate, a first hydraulic cylinder and a second hydraulic cylinder;

[0017] The intermediate transition frame is rotatably connected to the first-level movable upper plate through the middle plate rotation shaft. One end of the first-level hydraulic cylinder is rotatably connected to the first-level movable upper plate, and the other end of the first-level hydraulic cylinder is rotatably connected to the intermediate transition frame. Driven by the first-level hydraulic cylinder, the first-level movable upper plate rotates around the middle plate rotation shaft.

[0018] The first movable plate is overlapped with the second movable plate, one end of the second hydraulic cylinder is rotatably connected to the first movable plate, and the other end of the second hydraulic cylinder is rotatably connected to the second movable plate. Driven by the second hydraulic cylinder, the second movable plate is extended and retracted along the direction of chain movement, and the lower surface of the second movable plate is tangent to the sprocket shaft.

[0019] Furthermore, in the intermediate intelligent body, the motor drive system further comprises a lower middle plate and a lower middle plate hydraulic cylinder;

[0020] One end of the lower middle plate is rotatably connected to the middle groove through the middle plate rotating shaft, one end of the lower middle plate hydraulic cylinder is rotatably connected to the lower middle plate, and the other end of the lower middle plate hydraulic cylinder is rotatably connected to the middle groove.

[0021] Furthermore, one end of the lower middle plate facing the machine head is an arc.

[0022] Furthermore, in the intermediate intelligent agent, the torsional tensioning system further includes a tensioning wheel slider and a tensioning wheel hydraulic cylinder;

[0023] Both sides of the tensioning wheel shaft are fixedly connected to the tensioning wheel sliders, and a tensioning wheel slideway is provided on the turntable, and the tensioning wheel slider slides inside the tensioning wheel slideway; one end of the tensioning wheel hydraulic cylinder is rotatably connected to the turntable, and the other end of the tensioning wheel hydraulic cylinder is rotatably connected to the tensioning wheel slider, and the tensioning wheel hydraulic cylinder is used to drive the tensioning wheel to move.

[0024] Another aspect of the present invention provides a distributed multi-agent chain transmission control method for a scraper conveyor, wherein the power balance control of the motor is defined as a primary agent, and the tension balance control is defined as a secondary agent;

[0025] First, train the first-level agent separately. Then, train the second-level agent based on the fixed first-level agent strategy.

[0026] In the initial stage, the first-level agent quickly optimizes the motor power distribution when the system starts;

[0027] In the stable stage, after the power output of the first level tends to be balanced, the second level agent gradually adjusts the tension to reduce the uneven force on the chain;

[0028] In the dynamic adjustment section, when the power state of the first level changes, the second level agent responds in real time and readjusts the tension.

[0029] Furthermore, when performing motor power balance control, the state space is the output power, current, speed, load change rate of each motor, and the real-time power difference between motors; the action space is to adjust the speed of each motor; the multi-agent version of deep deterministic policy gradient (MADDPG) is used for training, and the reward function during training is:

[0030]

[0031] P i The actual output power of each motor; is the average power of all motors; N is the number of motors; C is the quantitative feedback index of chain tension fluctuation on power fluctuation; α and β are the weights of each item; where,

[0032]

[0033] k is the weight of tension fluctuation on reward, and v is the speed of the motor.

[0034] After the motor power training is completed, its strategy is fixed and then the secondary agent, namely the tension control, is trained. The state space is the tension state of the chain and the stress and strain data of each tensioning point. The action space is to adjust the torsion angle of each intermediate agent or the extension and contraction of the tensioner hydraulic cylinder. The MAPPO algorithm is used for training, and the reward function is:

[0035]

[0036] Among them, τj is the actual tensioning force at the jth tensioning point. The tensioning points are all the meshing and disengagement points between the sprocket and the chain. τ* is the desired target value, which can be selected according to the actual situation. V is the variance of the chain tensioning force, which is used to measure the dynamic tension variation range of each tensioning point in the chain. α, β, and γ are the weight values ​​of each item.

[0037] Compared with the prior art, the technical effects of the present invention include:

[0038] (1) The hydraulic tensioning system at the tail of the machine was eliminated and distributed chain tensioning was adopted, which reduced the area occupied by the tunnel and reduced the mining cost.

[0039] (2) Based on the combination of torsion and translation, a tensioning system structure is designed, which can tension the chains on both sides of the intermediate intelligent body simultaneously or perform unilateral tensioning.

[0040] (3) A hierarchical motor drive power balance and chain tensioning force coordinated control strategy is proposed. This strategy is also applicable to the current structure of the head and tail double-end motor drive and tail hydraulic chain tensioning system in the scraper conveyor, ensuring the stable coal transportation of the scraper conveyor.

[0041] (4) The control of motor drive and chain tension is realized based on the multi-agent deep reinforcement learning algorithm. The coordinated control of different fields is achieved through continuous data training, which can reduce the difficulty of control system development and multidisciplinary coupling control. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the structure of the scraper conveyor of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of the machine head intelligent body of the present invention;

[0044] Figure 3 This is a schematic diagram of the tail intelligent body structure of the present invention;

[0045] Figure 4 Schematic diagram of the intermediate intelligent agent structure of the present invention;

[0046] Figure 5 Schematic diagram of the local structure of the intermediate intelligent agent of the present invention Figure 1 ;

[0047] Figure 6 Schematic diagram of the local structure of the intermediate intelligent agent of the present invention Figure 2 ;

[0048] Figure 7 Schematic diagram of the local structure of the intermediate intelligent agent of the present invention Figure 3 ;

[0049] Figure 8 Schematic diagram of the local structure of the intermediate intelligent agent of the present invention Figure 4 .

[0050] In the figure, 1-head intelligent agent, 2-middle intelligent agent, 3-tail intelligent agent, 4-coal transport section;

[0051] 101-head permanent magnet motor, 102-head frame;

[0052] 201-middle transition frame, 202-frame, 203-turntable, 204-first movable upper plate, 205-second movable upper plate, 206-tensioning pulley, 207-tensioning pulley shaft, 208-tensioning pulley slider, 209-middle plate rotating shaft, 210-lower middle plate, 211-first hydraulic cylinder, 212-second hydraulic cylinder, 213-torsion hydraulic motor, 214-middle permanent magnet motor, 215-tensioning pulley hydraulic cylinder, 216-lower middle plate hydraulic cylinder;

[0053] 301- tail permanent magnet motor, 302- tail frame;

[0054] 401-middle groove, 402-chain, 403-scraper, 404-sprocket, 405-sprocket shaft. DETAILED DESCRIPTION

[0055] In order to make those skilled in the art better understand the present invention, the present invention is further clearly and completely described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless there is a conflict, the features in the embodiments and examples of this application can be combined with each other.

[0056] A typical embodiment of the present invention provides a distributed multi-agent chain transmission system for a scraper conveyor, such as Figure 1 As shown, the scraper conveyor includes a head intelligent body 1, a middle intelligent body 2, a tail intelligent body 3, and a coal conveyor 4. These four components can be assembled to meet different coal conveying lengths and requirements, ultimately forming a scraper conveyor of varying lengths. This embodiment distributes the driving power required by the scraper conveyor across multiple motors and eliminates the hydraulic tensioning device at the tail, adopting a multi-point hydraulic tensioning strategy.

[0057] Among them, the head intelligent body 1 is set at the head of the scraper conveyor. Figure 2 As shown, the head intelligent body 1 includes a head permanent magnet motor 101, which is installed on a head frame 102. The head permanent magnet motor 101 drives the sprocket 404, and then drives the chain 402 and the scraper 403 to carry out coal transportation.

[0058] Among them, the tail intelligent body 3 is set at the tail part of the scraper conveyor. Figure 3As shown, the tail intelligent body 3 includes a tail permanent magnet motor 301, which is installed on the tail frame 302. The tail permanent magnet motor 201 drives the sprocket 404, which in turn drives the chain 402 and the scraper 403 to transport coal.

[0059] The coal conveying section 4 is composed of a plurality of middle troughs 401. Different numbers of middle troughs 401 form scraper conveyors of different lengths and provide a running track for the shearer to cut the coal wall.

[0060] The intermediate intelligent body 2 includes a motor drive system and a torsional tensioning system. Figure 1 As shown, two sets of intermediate intelligent bodies are respectively arranged at the two ends of the middle part of the scraper conveyor.

[0061] The motor drive system includes a middle permanent magnet motor 214 , which drives the sprocket 404 to rotate.

[0062] In a preferred embodiment, the motor drive system further includes an intermediate transition frame 201 , a first movable middle plate 204 , a second movable middle plate 205 , a first hydraulic cylinder 211 and a second hydraulic cylinder 212 .

[0063] like Figure 5 As shown, the intermediate transition frame 201 is rotationally connected to the first-level movable middle plate 204 through the middle plate rotating shaft 209, one end of the first-level hydraulic cylinder 211 is rotationally connected to the first-level movable middle plate 204, and the other end of the first-level hydraulic cylinder 211 is rotationally connected to the intermediate transition frame 201. Under the drive of the first-level hydraulic cylinder 211, the first-level movable middle plate 204 rotates around the middle plate rotating shaft 209.

[0064] like Figure 6 As shown, the first movable middle plate 204 overlaps the second movable middle plate 205. One end of the second hydraulic cylinder 201 is rotatably connected to the first movable middle plate 204, and the other end of the second hydraulic cylinder 201 is rotatably connected to the second movable middle plate 205. Driven by the second hydraulic cylinder 212, the second movable middle plate 205 can be extended and retracted along the direction of movement of the chain 402. The lower surface of the second movable middle plate 205 is tangential to the sprocket shaft 405. This allows the torsional tensioning system to provide a closed conveying floor for the scraper during rotation, preventing coal from falling.

[0065] In another preferred embodiment, the motor drive system further includes a lower middle plate 210 and a lower middle plate hydraulic cylinder 216 .

[0066] like Figure 5As shown, one end of the lower middle plate 210 is rotatably connected to the middle trough 401 via the middle plate rotating shaft 209. One end of the lower middle plate hydraulic cylinder 216 is rotatably connected to the lower middle plate 210, while the other end of the lower middle plate hydraulic cylinder 216 is rotatably connected to the middle trough 401. The lower middle plate 210 can be rotated to various angles by extending and retracting the lower middle plate hydraulic cylinder 216. The end of the lower middle plate 210 facing the machine head is rounded to prevent coal from falling to the bottom during transportation.

[0067] The central permanent magnet motor 214 drives the sprocket 404, which in turn drives the chain 402 and scraper 403 to transport the coal. As the chain 402 passes through the central intelligent body, it first passes through the intermediate transition frame 201, then follows an S-shaped path before returning to the central trough 401. After passing the sprocket 404, the coal falls directly into the lower central trough 401 without passing through the tensioning wheel 206.

[0068] The torsional tensioning system is used to control the tensioning force, and the torsional tensioning system includes a frame 202 , a turntable 203 , a torsional hydraulic motor 213 , a tensioning wheel 206 and a tensioning wheel shaft 207 .

[0069] like Figure 4 As shown, the frame 202 is fixedly connected to the intermediate transition frame 201 and the central trough 401, respectively, providing support for the intermediate intelligent body. The turntable 203 is rotatably connected to the frame 202. The housing of the torsion hydraulic motor 213 is fixedly connected to the frame 202, and the output shaft of the torsion hydraulic motor 213 is fixedly connected to the turntable 203, driving the turntable 203 to rotate. The tensioning pulley shaft 207 is mounted on both sides of the turntable 203, and the tensioning pulley 206 is mounted on the tensioning pulley shaft 207. When the turntable 203 rotates clockwise, the chains 402 on both sides are simultaneously tensioned.

[0070] In a preferred embodiment, the torsional tensioning system further includes a tensioning wheel slider 208 and a tensioning wheel hydraulic cylinder 215 .

[0071] like Figure 6 、 Figure 7 As shown, both sides of the tensioning wheel shaft 207 are fixedly connected to the tensioning wheel slider 208, and the turntable 203 is provided with a tensioning wheel slideway. The tensioning wheel slider 203 slides inside the tensioning wheel slideway, thereby adjusting the chain tension on one side of the tensioning wheel 206 separately. Figure 8 As shown, one end of the tensioning wheel hydraulic cylinder 215 is rotatably connected to the turntable 203, and the other end of the tensioning wheel hydraulic cylinder 215 is rotatably connected to the tensioning wheel slider 208. The tensioning wheel hydraulic cylinder 215 is used to drive the tensioning wheel 206 to move.

[0072] Another typical embodiment of the present invention provides a control method based on the above-mentioned distributed multi-agent chain transmission system of the scraper conveyor,

[0073] This embodiment adopts a hierarchical control strategy based on multi-agent reinforcement learning, defining motor power balance control as the first-level agent and tension balance control as the second-level agent.

[0074] First, the first-level agent is trained separately to ensure that its power allocation strategy is optimized. Based on the fixed first-level agent strategy, the second-level agent is trained to reduce learning interference.

[0075] In the initial stage, the first-level intelligent agent quickly optimizes the motor power distribution when the system starts; in the stable stage, after the first-level power output tends to be balanced, the second-level intelligent agent gradually adjusts the tension to reduce uneven force on the chain; dynamic adjustment, when the first-level power state changes, the second-level intelligent agent responds in real time and readjusts the tension.

[0076] When performing motor power balancing control, the state space consists of each motor's output power, current, speed, load change rate, and real-time power differences between motors. The action space involves adjusting the speed of each motor. This system is trained using a multi-agent version of deep deterministic policy gradient (MADDPG).

[0077] First, the advantage function is calculated at each time step using the generalized advantage estimation (GAE)

[0078] Among them, δ t =R t +γ×V(S t+1 )-V(S t ).

[0079] Then, calculate the cumulative discounted reward G t :G t =R t +γ×R t+1 +γ 2 ×R t+2 +…, where the reward function is:

[0080]

[0081] P i The actual output power of each motor; is the average power of all motors; N is the number of motors; C is the quantitative feedback index of chain tension fluctuation on power fluctuation; α and β are the weights of each item; where,

[0082]

[0083] k is the weight of tension fluctuation on reward, and v is the speed of the motor.

[0084] Use the clipping objective function for policy optimization and the advantage function Bring in

[0085]

[0086] Among them, r t (θ) is the ratio of the current policy to the old policy, and ∈ is a hyperparameter that limits the amplitude of policy updates.

[0087] Use the mean squared error loss function to optimize the value network:

[0088]

[0089] Among them G t The Adam optimization algorithm is used to minimize the loss function and gradually improve the accuracy of system control.

[0090] After motor power training is complete, its strategy is fixed, and then training for the secondary agent, tension control, is performed. The state space includes the chain tension state and stress and strain data at each tensioning point; the action space involves adjusting the torsion angle of each intermediate agent or the extension and contraction of the tensioner hydraulic cylinder. This is trained using the MAPPO algorithm.

[0091] First, the advantage function is calculated at each time step using the generalized advantage estimation (GAE)

[0092] Among them, δ t =R t +γ×V(S t+1 )-V(S t ).

[0093] Then, calculate the cumulative discounted reward G t :G t =R t +γ×R t+1 +γ 2 ×R t+2 +…, the reward function is:

[0094]

[0095] Among them, τj is the actual tensioning force at the jth tensioning point. The tensioning points are all the meshing and disengagement points between the sprocket and the chain. τ* is the desired target value, which can be selected according to the actual situation. V is the variance of the chain tensioning force, which is used to measure the dynamic tension variation range of each tensioning point in the chain. α, β, and γ are the weight values ​​of each item.

[0096] Use the clipping objective function for policy optimization and the advantage function Bring in

[0097]

[0098] Among them, r t (θ) is the ratio of the current policy to the old policy, and ∈ is a hyperparameter that limits the amplitude of policy updates.

[0099] Use the mean squared error loss function to optimize the value network:

[0100] L(φ)=E[(V φ (S t )-G t ) 2 ]

[0101] Where Gt is the calculated cumulative discounted reward. The Adam optimization algorithm is used to minimize the loss function and gradually improve the accuracy of system control.

[0102] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention may have various variations and modifications. Any modifications, improvements and equivalent substitutions made within the concept and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A distributed multi-agent chain drive control system for a scraper conveyor, characterized in that: include: The head intelligent body is arranged at the head of the scraper conveyor, and includes a head permanent magnet motor, which is installed on the head frame and drives the sprocket; The tail intelligent body is arranged at the tail of the scraper conveyor and includes a tail permanent magnet motor installed on the tail frame, and the tail permanent magnet motor drives the sprocket; The coal conveying section consists of several middle chutes; The intermediate intelligent body includes a motor drive system and a torsion tensioning system; two sets of intermediate intelligent bodies are respectively arranged at the middle and two ends of the scraper conveyor; The motor drive system includes a middle permanent magnet motor, which drives the sprocket to rotate; The motor drive system also includes an intermediate transition frame, a first-level movable upper plate, a second-level movable upper plate, a first-level hydraulic cylinder and a second-level hydraulic cylinder; the intermediate transition frame is rotatably connected to the first-level movable upper plate through the middle plate rotating shaft, one end of the first-level hydraulic cylinder is rotatably connected to the first-level movable upper plate, and the other end of the first-level hydraulic cylinder is rotatably connected to the intermediate transition frame. Under the drive of the first-level hydraulic cylinder, the first-level movable upper plate rotates around the middle plate rotating shaft; the first-level movable upper plate is overlapped with the second-level movable upper plate, one end of the second-level hydraulic cylinder is rotatably connected to the first-level movable upper plate, and the other end of the second-level hydraulic cylinder is rotatably connected to the second-level movable upper plate. Under the drive of the second-level hydraulic cylinder, the second-level movable upper plate is extended and retracted along the movement direction of the chain, and the lower surface of the second-level movable upper plate is tangent to the sprocket shaft; The torsional tensioning system is used to control the tensioning force, and includes a frame, a turntable, a torsional hydraulic motor, a tensioning wheel and a tensioning wheel shaft; the frame is fixedly connected to the middle transition frame and the middle slot respectively, the turntable is rotatably connected to the frame, the torsional hydraulic motor housing is fixedly connected to the frame, and the torsional hydraulic motor output shaft is fixedly connected to the turntable to drive the turntable to rotate; the tensioning wheel shaft is installed on the turntables on both sides, and the tensioning wheel is installed on the tensioning wheel shaft; The torsional tensioning system also includes a tensioning wheel slider and a tensioning wheel hydraulic cylinder; both sides of the tensioning wheel shaft are fixedly connected to the tensioning wheel slider, and a tensioning wheel slideway is provided on the turntable, and the tensioning wheel slider slides inside the tensioning wheel slideway; one end of the tensioning wheel hydraulic cylinder is rotatably connected to the turntable, and the other end of the tensioning wheel hydraulic cylinder is rotatably connected to the tensioning wheel slider, and the tensioning wheel hydraulic cylinder is used to drive the tensioning wheel to move; The power balance control of the motor is defined as the first-level intelligent agent, and the balance control of the tension force is defined as the second-level intelligent agent; First, train the first-level agent separately. Then, train the second-level agent based on the fixed first-level agent strategy. In the initial stage, the first-level agent quickly optimizes the motor power distribution when the system starts; In the stable stage, after the power output of the first level tends to be balanced, the second level agent gradually adjusts the tension to reduce the uneven force on the chain; In the dynamic adjustment section, when the power state of the first level changes, the second level agent responds in real time and readjusts the tension.

2. The distributed multi-agent chain drive control system for scraper conveyors according to claim 1 is characterized in that: In the intermediate intelligent body, the motor drive system further comprises a lower middle plate and a lower middle plate hydraulic cylinder; One end of the lower middle plate is rotatably connected to the middle groove through the middle plate rotating shaft, one end of the lower middle plate hydraulic cylinder is rotatably connected to the lower middle plate, and the other end of the lower middle plate hydraulic cylinder is rotatably connected to the middle groove.

3. The distributed multi-agent chain drive control system for scraper conveyors according to claim 2, characterized in that: One end of the lower middle plate facing the machine head is an arc.

4. The distributed multi-agent chain drive control system for scraper conveyors according to claim 3 is characterized in that: When performing motor power balance control, the state space is the output power, current, speed, load change rate of each motor, and the real-time power difference between motors; the action space is to adjust the speed of each motor. The multi-agent version of deep deterministic policy gradient (MADDPG) is used for training, and the reward function during training is: ； P i The actual output power of each motor; is the average power of all motors; N is the number of motors; C It is a quantitative indicator of the feedback of chain tension fluctuation to power fluctuation; α 、 β is the weight of each item; ； k is the weight of tension fluctuation on reward, v is the motor speed.

5. The distributed multi-agent chain drive control system for scraper conveyors according to claim 4 is characterized in that: After the motor power training is completed, its strategy is fixed and then the secondary agent, namely the tension control, is trained. The state space is the tension state of the chain and the stress and strain data of each tensioning point. The action space is to adjust the torsion angle of each intermediate agent or the extension and contraction of the tensioner hydraulic cylinder. The MAPPO algorithm is used for training, and the reward function is: ； in, τ j is the actual tensioning force at the jth tensioning point, where the tensioning points are the meshing and separation points between the sprocket and the chain. τ * is the desired target value, which can be selected according to the actual situation; V is the variance of the chain tension force, which is used to measure the dynamic tension variation range of each tensioning point in the chain; α 、 β 、 γ is the weight value of each item.

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