A control system of a downward belt conveyor based on a four-quadrant variable frequency speed regulation integrated machine

Abstract

The application discloses a control system of a downward conveying belt conveyor based on a four-quadrant variable frequency speed regulation integrated machine, which utilizes the four-quadrant variable frequency speed regulation integrated machine to synchronously start a disc brake during a starting stage of the downward conveying belt conveyor, and to apply a reverse force to the downward conveying belt conveyor when the disc brake is fully opened; the control system controls a belt tensioning system to tension and adjust the belt according to a current running state during a running stage of the downward conveying belt conveyor; and the control system generates a braking torque to control the belt to slow down and stop during a stopping stage of the downward conveying belt conveyor; the problems of running, belt slipping and abnormal stopping of the downward conveying belt during heavy load starting, heavy load running and heavy load stopping are solved, and the stable and reliable running of the whole belt system is ensured.

Description

Technical Field

[0001] This invention relates to the field of conveyor belt control technology, specifically to a conveyor belt control system based on a four-quadrant variable frequency speed control integrated machine. Background Technology

[0002] With the continuous advancement of industrial development, the coal mining industry has increasingly higher requirements for the automation level, operating efficiency, safety, and reliability of underground equipment. Among these, conveyor belts often experience runaway and slippage during heavy-load operation, which seriously affects the safety and stability of underground coal transportation. Summary of the Invention

[0003] To address the aforementioned shortcomings in the existing technology, this invention provides a control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine, aiming to solve problems such as runaway conveyors, belt slippage, and inability to stop normally during heavy-load start-up, heavy-load operation, and heavy-load shutdown of the conveyor belt, thereby ensuring the safety and reliability of the conveyor belt during transportation.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0005] A control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine includes:

[0006] The four-quadrant variable frequency speed control integrated machine is used to start synchronously when the disc brake is activated during the starting stage of the conveyor belt, and to apply a reverse force to the conveyor belt when the disc brake is fully opened; during the running stage of the conveyor belt, it controls the belt tensioning system to adjust the belt tension according to the current running status; and during the stopping stage of the conveyor belt, it generates braking torque to control the belt deceleration and stopping.

[0007] The conveyor belt conveyor is used for operation control based on the drive signal of the four-quadrant frequency converter speed control integrated machine.

[0008] Optionally, the four-quadrant variable frequency speed control integrated machine specifically includes:

[0009] Two four-quadrant variable frequency speed control integrated machines are used to form a master-slave drive mode. The master machine uses DTC mode to control the speed of the conveyor belt, and the slave machine uses DTC mode to control the torque of the conveyor belt.

[0010] Optionally, when the disc brake is fully engaged during the startup phase of the conveyor belt, the four-quadrant variable frequency speed control unit applies a reverse force to the conveyor belt, specifically including:

[0011] The speed parameters of the conveyor belt motor driven by the host and the torque parameters of the conveyor belt motor driven by the slave are collected respectively. The PID algorithm is used to control the given torque of the slave so that the slave generates braking torque on the host, thereby applying a reverse force to the conveyor belt.

[0012] Optionally, using a PID algorithm to control the given torque of the slave device specifically includes:

[0013] The speed difference between the given speed of the master unit and the operating speed is used as the input variable for the PID algorithm to obtain the given torque of the slave unit.

[0014] Alternatively, the given torque of the slave device can be expressed as:

[0015]

[0016] Where u(k) is the given torque of the slave, Kp is the proportional coefficient, e(k) is the speed difference at the current moment, T is the time base coefficient, Ti is the integration time, j is the cumulative variable, k is the cumulative upper limit, e(j) is the speed error at time j, e(j-1) is the speed error at time j-1, Td is the differential coefficient, and e(k-1) is the speed difference at the previous moment.

[0017] Optionally, the four-quadrant variable frequency speed control integrated machine controls the belt tensioning system to adjust the belt tension according to the current operating status during the operation of the conveyor belt. Specifically, this includes:

[0018] Collect the pressure value of the conveyor belt during operation, the torque parameters of the conveyor belt motor driven by the host machine and the torque parameters of the conveyor belt motor driven by the slave machine.

[0019] The master-slave torque difference is determined based on the torque parameters of the conveyor belt motor driven by the master and the torque parameters of the conveyor belt motor driven by the slave.

[0020] Based on the pressure value of the conveyor belt and the difference between the master and slave torques during the operation of the conveyor belt machine, the tension control strength of the conveyor belt during the operation of the conveyor belt machine is obtained by using a fuzzy control algorithm.

[0021] The belt tensioning system adjusts the belt tension according to the required tension during the operation of the conveyor belt.

[0022] Optionally, based on the pressure value of the conveyor belt and the master-slave torque difference during the operation of the conveyor belt, a fuzzy control algorithm is used to obtain the tension control strength of the conveyor belt during operation, specifically including:

[0023] The pressure value and master-slave torque difference of the conveyor belt during operation are fuzzified to obtain the pressure universe, pressure fuzzy label, master-slave torque difference universe, torque difference fuzzy label, belt tensioning system control strength universe and tension fuzzy label;

[0024] Define the membership function of pressure and construct the fuzzy set of the membership of pressure using the ordered pair representation method;

[0025] Define the membership function of torque and construct the fuzzy set of membership of torque using the ordered pair representation method;

[0026] Based on the preset control strategy, the input fuzzy labels and output fuzzy labels are described by fuzzy conditional statements to establish a fuzzy rule table;

[0027] Determine the fuzzy set of membership degrees of the tape tensioning system based on the fuzzy rule table;

[0028] For the input parameters that satisfy the fuzzy set of membership degrees of the conveyor belt tensioning system, the weighted average method is used for defuzzification calculation to obtain the tension control strength of the conveyor belt during operation of the conveyor belt machine.

[0029] Optionally, the tension control strength of the conveyor belt during operation is expressed as:

[0030]

[0031] Where y is the tension control strength of the conveyor belt during operation of the conveyor belt machine, m is the number of memberships in the fuzzy set of the belt tensioning system, i is the index of the membership in the fuzzy set of the belt tensioning system, and μ is the number of memberships. D (x i (where x is the pressure) i Membership degree at time, x i Let k be the pressure corresponding to the i-th membership degree, D be the fuzzy set of membership degrees of the tape tensioning system, and k be the pressure corresponding to the i-th membership degree. i is the universe value corresponding to the i-th membership degree.

[0032] Optionally, the four-quadrant variable frequency speed control unit generates braking torque during the stopping phase of the conveyor belt to control the belt speed reduction and stop, specifically including:

[0033] The running speed of the conveyor belt at each braking time is determined based on the deceleration and braking function;

[0034] The corresponding braking torque is generated based on the running speed of the conveyor belt at each braking time.

[0035] The belt is decelerated and stopped based on the generated braking torque.

[0036] Alternatively, the deceleration braking function can be expressed as:

[0037]

[0038] Where v(t) is the running speed of the conveyor belt during the braking time t, and v0 is the speed at the start of deceleration braking.

[0039] The present invention has the following beneficial effects:

[0040] This invention utilizes a four-quadrant variable frequency speed control integrated machine to synchronously start the conveyor belt when the disc brake is applied during the starting phase, and to apply a reverse force to the conveyor belt when the disc brake is fully released; during the operation phase of the conveyor belt, the belt tensioning system is controlled to adjust the belt tension according to the current operating status; during the shutdown phase of the conveyor belt, braking torque is generated to decelerate and stop the belt; this invention solves the problems of runaway belts, belt slippage, and inability to stop normally that occur during heavy-load start-up, heavy-load operation, and heavy-load shutdown of the conveyor belt, ensuring the stable and reliable operation of the entire conveyor belt system. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine.

[0042] Figure 2 This is a block diagram of the PID control principle. Detailed Implementation

[0043] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0044] like Figure 1 As shown, this embodiment of the invention provides a control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine, including:

[0045] The four-quadrant variable frequency speed control integrated machine is used to start synchronously when the disc brake is activated during the starting stage of the conveyor belt, and to apply a reverse force to the conveyor belt when the disc brake is fully opened; during the running stage of the conveyor belt, it controls the belt tensioning system to adjust the belt tension according to the current running status; and during the stopping stage of the conveyor belt, it generates braking torque to control the belt deceleration and stopping.

[0046] The conveyor belt is used for operation control based on the drive signal of the four-quadrant frequency converter speed control integrated machine.

[0047] In this embodiment, the four-quadrant integrated machine collects analog signals such as motor current, torque, and speed during operation, converts them into digital signals by the analog-to-digital converter module, and sends them to the control box via the CAN bus. Finally, the integrated machine control box controls the operation of the integrated machine, the start and stop of the disc brake, and the tensioning system.

[0048] In an optional embodiment of the present invention, during the start-up phase of the conveyor belt, the traditional control scheme is to first open the disc brake, and then start the four-quadrant variable frequency speed control unit after the disc brake is fully open. However, in this case, when the conveyor belt is under heavy load, the conveyor belt will run on its own before the start command is given due to gravity. Therefore, to address this problem, this embodiment controls the start of the disc brake and starts the four-quadrant variable frequency speed control unit at the same time. When the disc brake is fully open, the four-quadrant variable frequency speed control unit applies a counter-force to the conveyor belt to counteract the gravitational potential energy when the conveyor belt is under heavy load, thus preventing the conveyor belt from running away during the process of the disc brake being fully open.

[0049] In order to more accurately control the anti-phase force of the four-quadrant variable frequency speed control integrated machine, this embodiment adds a PID control algorithm in the control program startup stage to control the four-quadrant variable frequency speed control integrated machine to form an anti-phase force on the conveyor belt to counteract the gravitational potential energy of the conveyor belt.

[0050] In this embodiment, the four-quadrant variable frequency speed control integrated machine specifically includes:

[0051] Two four-quadrant variable frequency speed control integrated machines are used to form a master-slave drive mode. The master machine uses DTC mode to control the speed of the conveyor belt, and the slave machine uses DTC mode to control the torque of the conveyor belt.

[0052] In this embodiment, the four-quadrant variable frequency speed control integrated machine applies a reverse force to the conveyor belt when the disc brake is fully opened during the start-up phase of the conveyor belt. Specifically, this includes:

[0053] The speed parameters of the conveyor belt motor driven by the host and the torque parameters of the conveyor belt motor driven by the slave are collected respectively. The PID algorithm is used to control the given torque of the slave so that the slave generates braking torque on the host, thereby applying a reverse force to the conveyor belt.

[0054] Specifically, this embodiment uses two four-quadrant variable frequency speed control integrated machines for driving. One four-quadrant variable frequency speed control integrated machine is set as the master, and the other four-quadrant variable frequency speed control integrated machine is the slave. At startup, the master uses speed control in DTC mode. By controlling the output frequency of the four-quadrant variable frequency speed control integrated machine, the output speed of the four-quadrant variable frequency speed control integrated machine is maintained in a controllable manner. The slave uses torque control in DTC mode. By controlling the output torque of the four-quadrant variable frequency speed control integrated machine, the output power of the four-quadrant variable frequency speed control integrated machine is made controllable. The torque is given by controlling the magnitude of the given torque through a PID algorithm, thereby forming a braking torque for the master through the slave.

[0055] In this embodiment, the PID algorithm is used to control the given torque of the slave device, specifically including:

[0056] The speed difference between the given speed of the master unit and the operating speed is used as the input variable for the PID algorithm to obtain the given torque of the slave unit.

[0057] In this embodiment, the given torque of the slave device is expressed as:

[0058]

[0059] Where u(k) is the given torque of the slave, Kp is the proportional coefficient, e(k) is the speed difference at the current moment, T is the time base coefficient, Ti is the integration time, j is the cumulative variable, k is the cumulative upper limit, e(j) is the speed error at time j, e(j-1) is the speed error at time j-1, Td is the differential coefficient, and e(k-1) is the speed difference at the previous moment.

[0060] Specifically, Figure 2 A block diagram of PID control principle is given, where r(t) represents the given speed of the host, v(t) represents the actual speed of the host, e(t) represents the speed deviation, and u(t) represents the given torque value of the slave.

[0061] During startup, the host machine is given a speed of 0. As the disc brake gradually opens, the conveyor belt also gradually begins to move. At this time, the host machine's given speed r(t) and the running speed v(t) form a speed difference e(t), which serves as the input variable for the PID control algorithm.

[0062] In the PID control algorithm, this system uses an incremental algorithm to obtain the integral value:

[0063] I(k) = I(k-1) + ΔI(k)

[0064] Where I(k) is the integral at time k, I(k-1) is the integral at time (k-1), and ΔI(k) is the accumulated deviation over time.

[0065] The formula for calculating the given torque of the slave device is expressed as:

[0066]

[0067] Where u(k) is the given torque of the slave, Kp is the proportional coefficient, e(k) is the speed difference at the current moment, T is the time base coefficient, Ti is the integration time, j is the cumulative variable, k is the cumulative upper limit, e(j) is the speed error at time j, e(j-1) is the speed error at time j-1, Td is the differential coefficient, and e(k-1) is the speed difference at the previous moment.

[0068] Finally, the obtained u(k) is used as the setpoint for the slave torque control to control the slave to give a counter-force to the downstream conveyor belt, so as to prevent the downstream conveyor belt from running away.

[0069] This embodiment avoids the runaway problem during heavy-load startup by introducing a PID control algorithm during the startup phase and combining speed and torque control in the variable frequency DTC mode.

[0070] In an optional embodiment of the present invention, during system operation, the belt load fluctuates continuously with the change in coal mining volume. As the operating time increases, the tension of the conveyor belt will decrease, which in turn affects the power balance of the entire belt and causes uneven output of the two four-quadrant variable frequency speed control integrated machines. Therefore, during belt operation, it is necessary to control the belt tensioning system to tension the belt according to the operating status of the four-quadrant variable frequency speed control integrated machine.

[0071] Since manual tensioning can easily lead to problems such as untimely tensioning and over-tensioning, this embodiment uses a fuzzy control algorithm to control the start and stop of the tensioning system.

[0072] In this embodiment, the four-quadrant variable frequency speed control integrated machine controls the belt tensioning system to adjust the belt tension according to the current operating status during the operation of the conveyor belt. Specifically, this includes:

[0073] Collect the pressure value of the conveyor belt during operation, the torque parameters of the conveyor belt motor driven by the host machine and the torque parameters of the conveyor belt motor driven by the slave machine.

[0074] The master-slave torque difference is determined based on the torque parameters of the conveyor belt motor driven by the master and the torque parameters of the conveyor belt motor driven by the slave.

[0075] Based on the pressure value of the conveyor belt and the difference between the master and slave torques during the operation of the conveyor belt machine, the tension control strength of the conveyor belt during the operation of the conveyor belt machine is obtained by using a fuzzy control algorithm.

[0076] The belt tensioning system adjusts the belt tension according to the required tension during the operation of the conveyor belt.

[0077] In this embodiment, based on the pressure value of the conveyor belt and the master-slave torque difference during the operation of the conveyor belt machine, the tension control strength of the conveyor belt during operation is obtained using a fuzzy control algorithm, specifically including:

[0078] The pressure value and master-slave torque difference of the conveyor belt during operation are fuzzified to obtain the pressure universe, pressure fuzzy label, master-slave torque difference universe, torque difference fuzzy label, belt tensioning system control strength universe and tension fuzzy label;

[0079] Define the membership function of pressure and construct the fuzzy set of the membership of pressure using the ordered pair representation method;

[0080] Define the membership function of torque and construct the fuzzy set of membership of torque using the ordered pair representation method;

[0081] Based on the preset control strategy, the input fuzzy labels and output fuzzy labels are described by fuzzy conditional statements to establish a fuzzy rule table;

[0082] Determine the fuzzy set of membership degrees of the tape tensioning system based on the fuzzy rule table;

[0083] For the input parameters that satisfy the fuzzy set of membership degrees of the conveyor belt tensioning system, the weighted average method is used for defuzzification calculation to obtain the tension control strength of the conveyor belt during operation of the conveyor belt machine.

[0084] Specifically, in this embodiment, the analog signal from the pressure sensor is converted into a digital signal via an AD conversion module and transmitted to the integrated control box as one of the input conditions for whether the belt tensioning system is activated. Additionally, the absolute value of the torque difference between the master and slave integrated units is used as another input condition, and the control method of the belt tensioning system is used as the output condition.

[0085] The above input and output conditions are fuzzified to obtain the pressure universe of discourse as [0,c], where c represents the upper limit of pressure and the pressure fuzzy label is {small, relatively small, large}. The master-slave torque difference universe of discourse is Y = [0.100] and the torque difference fuzzy label is {good, relatively poor, poor}. The universe of discourse of the control strength of the conveyor belt tensioning system is Z = [0,1] and the tension fuzzy label is {weak, strong}.

[0086] Let A be the fuzzy set of the membership degrees of pressure, and let the membership function be:

[0087]

[0088] Where, μ A Let x be the membership degree of the pressure, a be the current pressure, and b be the node in the pressure universe interval.

[0089] The fuzzy set A of the membership degrees of pressure is represented using the ordered pair notation as follows:

[0090]

[0091] Where u represents the membership degree.

[0092] The fuzzy set of membership degrees for torque is B, and the membership function is:

[0093]

[0094] The membership fuzzy set B of torque is represented using the ordered pair notation as follows:

[0095]

[0096] According to the preset control strategy, the input fuzzy tags and output fuzzy tags are described using fuzzy conditional statements, for example:

[0097] 1. If the pressure is "low" and the torque difference is "poor", then the tension control strength is "strong".

[0098] 2. If the pressure is "low" and the torque difference is "poor", then the tension control strength is "strong".

[0099] 3. If the pressure is "high" and the torque difference is "poor", then the tension control strength is "weak".

[0100] 4. If the pressure is "low" and the torque difference is "poor", then the tension control strength is "strong".

[0101] 5. If the pressure is "low" and the torque difference is "poor", then the tension control strength is "strong".

[0102] 6. If the pressure is "high" and the torque difference is "poor", then the tension control strength is "weak".

[0103] 7. If the pressure is "low" and the torque difference is "good", then the tension control strength is "weak".

[0104] 8. If the pressure is "low" and the torque difference is "good", then the tension control strength is "weak".

[0105] 9. If the pressure is "high" and the torque difference is "good", then the tension control strength is "weak".

[0106] Based on the above fuzzy conditional statements, a fuzzy rule table is established:

[0107]

[0108] According to the fuzzy rules in the table, an output decision will only be triggered if both fuzzy matrices A and B satisfy the AND relationship. Therefore, the fuzzy set D of the tensioned system is the intersection of matrices A and B.

[0109] D = A ∩ B

[0110] Its membership degree is:

[0111] μ D (x)=min(μ A (x), μ B (x))

[0112] Based on the current system input parameters satisfying the tension control membership matrix D, the tension control strength of the conveyor belt during operation is obtained by defuzzifying D using the enhanced averaging method:

[0113]

[0114] Where y is the tension control strength of the conveyor belt during operation of the conveyor belt machine, m is the number of memberships in the fuzzy set of the belt tensioning system, i is the index of the membership in the fuzzy set of the belt tensioning system, and μ is the number of memberships. D (x i (where x is the pressure) i Membership degree at time, x i Let k be the pressure corresponding to the i-th membership degree, D be the fuzzy set of membership degrees of the tape tensioning system, and k be the pressure corresponding to the i-th membership degree. i is the universe value corresponding to the i-th membership degree.

[0115] This embodiment introduces a fuzzy control algorithm into the tensioning system control during operation, enabling automatic adjustment of the tensioning system during belt operation and reducing uneven output of the master and slave motors caused by insufficient belt tension.

[0116] In an optional embodiment of the present invention, when the system stops under heavy load, the conveyor belt is moving too fast and has a large inertia. It is difficult to stop the conveyor belt in a short time by directly giving the four-quadrant variable frequency speed control integrated machine a stop signal and controlling the disc brake at the same time. To address this problem, this embodiment adds a deceleration and stop control when preparing to stop the conveyor belt. The running speed of the conveyor belt is reduced by the braking torque during the deceleration process of the four-quadrant variable frequency speed control integrated machine. Finally, the disc brake is controlled after the conveyor belt stops.

[0117] In this embodiment, the four-quadrant variable frequency speed control integrated machine generates braking torque to decelerate and stop the conveyor belt during the stopping phase of the conveyor belt, specifically including:

[0118] The running speed of the conveyor belt at each braking time is determined based on the deceleration and braking function;

[0119] The corresponding braking torque is generated based on the running speed of the conveyor belt at each braking time.

[0120] The belt is decelerated and stopped based on the generated braking torque.

[0121] In this embodiment, the deceleration and braking function is expressed as follows:

[0122]

[0123] Where v(t) is the running speed of the conveyor belt during the braking time t, and v0 is the speed at the start of deceleration braking.

[0124] This embodiment avoids the phenomenon that the conveyor belt cannot stop running when the machine is stopped directly under heavy load by using a deceleration braking control method during the braking phase.

[0125] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0126] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0127] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0128] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

[0129] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine, characterized in that, include: The four-quadrant variable frequency speed control integrated machine is used to synchronously start the conveyor belt when the disc brake is engaged during the starting phase, and to apply a reverse force to the conveyor belt when the disc brake is fully disengaged. Specifically, the reverse force applied by the four-quadrant variable frequency speed control integrated machine when the disc brake is fully disengaged during the starting phase of the conveyor belt includes: The speed parameters of the conveyor belt motor driven by the master and the torque parameters of the conveyor belt motor driven by the slave are collected respectively. A PID algorithm is used to control the given torque of the slave motor, so that the slave motor generates braking torque on the master, thereby applying a reverse force to the conveyor belt. Specifically, the PID algorithm for controlling the given torque of the slave motor includes: The speed difference between the host's given speed and the operating speed is used as the input variable for the PID algorithm to obtain the slave's given torque. During the operation of the conveyor belt, the belt tensioning system is controlled to adjust the belt tension according to the current operating status. Specifically, the four-quadrant variable frequency speed control unit controls the belt tensioning system to adjust the belt tension according to the current operating status during the operation of the conveyor belt, including: Collect the pressure value of the conveyor belt during operation, the torque parameters of the conveyor belt motor driven by the host machine and the torque parameters of the conveyor belt motor driven by the slave machine. The master-slave torque difference is determined based on the torque parameters of the conveyor belt motor driven by the master and the torque parameters of the conveyor belt motor driven by the slave. Based on the pressure value of the conveyor belt and the difference between the master and slave torques during the operation of the conveyor belt machine, the tension control strength of the conveyor belt during the operation of the conveyor belt machine is obtained by using a fuzzy control algorithm. The belt tensioning system adjusts the belt tension according to the belt tension control intensity during the operation of the conveyor belt. Based on the pressure value of the conveyor belt and the difference between the master and slave torques during the operation of the conveyor belt, the tension control strength of the conveyor belt during operation is obtained using a fuzzy control algorithm, specifically including: The pressure value and master-slave torque difference of the conveyor belt during operation are fuzzified to obtain the pressure universe, pressure fuzzy label, master-slave torque difference universe, torque difference fuzzy label, belt tensioning system control strength universe and tension fuzzy label; Define the membership function of pressure and construct the fuzzy set of the membership of pressure using the ordered pair representation method; Define the membership function of torque and construct the fuzzy set of membership of torque using the ordered pair representation method; Based on the preset control strategy, the input fuzzy labels and output fuzzy labels are described by fuzzy conditional statements to establish a fuzzy rule table; Determine the fuzzy set of membership degrees of the tape tensioning system based on the fuzzy rule table; For the input parameters that satisfy the fuzzy set of membership degrees of the conveyor belt tensioning system, the weighted average method is used for defuzzification calculation to obtain the tension control strength of the conveyor belt during the operation of the conveyor belt machine. During the shutdown phase of the conveyor belt machine, a braking torque is generated to decelerate and stop the conveyor belt. The four-quadrant variable frequency speed control integrated machine specifically includes: Two four-quadrant variable frequency speed control integrated machines are used to form a master-slave drive mode. The master machine uses DTC mode to control the speed of the conveyor belt, and the slave machine uses DTC mode to control the torque of the conveyor belt. The conveyor belt conveyor is used for operation control based on the drive signal of the four-quadrant frequency converter speed control integrated machine.

2. The control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine according to claim 1, characterized in that, The given torque of the slave is expressed as: ； in, Given the torque of the slave device, This is the proportionality coefficient. This represents the speed difference at the current moment. As a time base coefficient, For integration time, For cumulative variables, For accumulation and upper limit, for Rotational speed error at any given time for Rotational speed error at any given time These are the differential coefficients. This represents the speed difference from the previous moment.

3. The control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine according to claim 1, characterized in that, The tension control strength of the conveyor belt during operation is expressed as: ； in, To control the tension of the conveyor belt during operation of the conveyor belt machine. Let be the number of membership degrees in the fuzzy set of membership degrees of the tape tensioning system. Let be the index of the membership degree in the fuzzy set of membership degrees of the tape tensioning system. For pressure Membership degree at that time The pressure corresponding to the i-th membership degree. Let be the fuzzy set of membership degrees of the tape tensioning system. is the universe value corresponding to the i-th membership degree.

4. The control system for a conveyor belt based on a four-quadrant variable frequency speed control integrated machine according to claim 1, characterized in that, The four-quadrant variable frequency speed control integrated machine generates braking torque during the stopping phase of the conveyor belt to control the belt deceleration and shutdown. Specifically, this includes: The running speed of the conveyor belt at each braking time is determined based on the deceleration and braking function; The corresponding braking torque is generated based on the running speed of the conveyor belt at each braking time. The belt is decelerated and stopped based on the generated braking torque.

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