Material conveying system and method of material conveying control

Abstract

The present application relates to material conveying technical field, disclose material conveying system and material conveying control method. Material conveying system includes: upstream conveyor; downstream conveyor, set downstream of upstream conveyor; buffer bin, with inlet and outlet, inlet corresponds to the head of upstream conveyor; feeder, set at the outlet, feeder is located above the tail of downstream conveyor; first material detection piece, for detecting the actual volume of upstream conveyor; second material detection piece, for detecting the actual buffer capacity in buffer bin; controller, interlock with upstream conveyor, downstream conveyor, feeder, controller is used for controlling the feeding amount of feeder and the speed of downstream conveyor according to the actual volume of upstream conveyor and the actual buffer capacity in buffer bin. By stabilizing the cross-sectional area of the material of downstream conveyor, dynamically adjusting the speed of downstream conveyor, so that the downstream conveyor runs stably, reduces energy consumption.

Description

Technical Field

[0001] This invention relates to the field of material conveying technology, and more specifically to material conveying systems and material conveying control methods. Background Technology

[0002] Long-distance conveyors typically follow undulating terrain and include multiple horizontal turning sections. When the incoming material is unstable, several transient operating conditions arise, causing a temporary increase in conveyor operating tension, a sudden increase in power and energy consumption, and increased energy consumption for material transport. Turning sections may also lead to material spillage. Furthermore, the design strength of long-distance conveyors must accommodate various operating conditions, resulting in increased design strength redundancy. This makes long-distance conveyors more demanding on material stability compared to ordinary conveyors. Upstream of long-distance conveyors is often supplied by rudimentary stockpiles, which are prone to uneven feeding, material interruptions, and poor feeding stability. This not only causes large tension fluctuations and unstable operation of the long-distance conveyor but also reduces its utilization rate and increases energy consumption. Summary of the Invention

[0003] In view of this, the present invention provides a material conveying system and a material conveying control method to solve the problems of uneven upstream feeding and material interruption leading to unstable operation and increased energy consumption of long-distance conveyors.

[0004] In a first aspect, the present invention provides a material conveying system, comprising: an upstream conveyor; a downstream conveyor disposed downstream of the upstream conveyor; a buffer bin having an inlet and an outlet, the inlet corresponding to the head of the upstream conveyor; a feeder disposed at the outlet, the feeder being located above the tail of the downstream conveyor; a first material detection element for detecting the actual conveying capacity of the upstream conveyor; a second material detection element for detecting the actual buffered quantity in the buffer bin; and a controller interlocked with the upstream conveyor, the downstream conveyor, and the feeder, the controller being used to control the feeding rate of the feeder and the belt speed of the downstream conveyor based on the actual conveying capacity of the upstream conveyor and the actual buffered quantity in the buffer bin.

[0005] Beneficial effects: Buffer bins are installed at the head of the upstream conveyor and the tail of the downstream conveyor. These buffer bins buffer the material transported by the upstream conveyor. The feeding speed is controlled by a feeder at the outlet of the buffer bin, ensuring uniform feeding to the downstream conveyor. This stabilizes the cross-sectional area of ​​the material in the downstream conveyor and dynamically adjusts its belt speed, resulting in stable operation and reduced energy consumption. It effectively prevents frequent switching of operating conditions, poor operational stability, low utilization, and increased energy consumption in the downstream conveyor due to uneven feeding or material interruptions from the upstream. Furthermore, the controller controls the feeder's rate and the downstream conveyor's belt speed based on the actual transport volume of the upstream conveyor and the actual buffer volume in the buffer bin, thus ensuring the stability of the material cross-sectional area in the downstream conveyor and preventing material interruptions.

[0006] In one optional embodiment, the material conveying system further includes a third material detection element and a fourth material detection element. The third material detection element is located near the feeder and is used to detect the amount of material conveyed by the feeder to the downstream conveyor. The fourth material detection element is located at the head of the downstream conveyor and is used to detect the amount of material that has been conveyed by the downstream conveyor. The controller is used to control the feed rate of the feeder and the belt speed of the downstream conveyor based on the actual buffer capacity of the buffer bin, the amount of material being conveyed by the downstream conveyor, the total amount of material to be conveyed by the material conveying system this time, and the amount of material already conveyed by the downstream conveyor.

[0007] Beneficial effects: By changing the speed of long-distance conveyors, the operating power is reduced, the utilization rate of downstream conveyors is improved, the problem of increased energy consumption per ton of material is avoided, and the stability of the cross-sectional area of ​​the material in the downstream conveyor can be effectively guaranteed, avoiding phenomena such as material interruption.

[0008] Secondly, the present invention also provides a material conveying control method for controlling the aforementioned material conveying system. The material conveying control method includes the following steps: obtaining the actual conveying capacity of the upstream conveyor and the actual buffer capacity in the buffer bin of the material conveying system; and controlling the feeding rate of the feeder and the belt speed of the downstream conveyor of the material conveying system based on the actual conveying capacity of the upstream conveyor and the actual buffer capacity in the buffer bin.

[0009] Beneficial effects: By adjusting the feed rate of the feeder and the belt speed of the downstream conveyor based on the actual carrying capacity of the upstream conveyor and the actual buffer capacity in the buffer bin, the feed rate of the feeder can be adjusted to ensure uniform feeding of the downstream conveyor, thereby making the downstream conveyor run stably, reducing energy consumption, and effectively avoiding the situation where the downstream conveyor frequently switches operating conditions, has poor operating stability, low utilization rate, and increased energy consumption due to uneven feeding or material interruption from the upstream.

[0010] In one optional implementation, the step of controlling the feed rate of the feeder and the belt speed of the downstream conveyor in the material conveying system based on the actual transport capacity of the upstream conveyor and the actual buffer capacity in the buffer bin includes: determining whether the fluctuation value of the transport capacity of the upstream conveyor within a preset time is greater than a transport capacity fluctuation threshold; determining whether the actual buffer capacity in the buffer bin is greater than or equal to a lower buffer limit; determining whether the actual buffer capacity in the buffer bin is greater than or equal to the lower buffer limit, then controlling the feeder to operate at the rated feed rate and the downstream conveyor to operate at the rated belt speed and rated transport capacity; determining whether the actual buffer capacity in the buffer bin is less than the lower buffer limit, then adjusting the feed rate of the feeder and the belt speed of the downstream conveyor based on the actual buffer capacity in the buffer bin, the amount of material being transported by the downstream conveyor, and the amount of material that the material conveying system has not yet completed.

[0011] Beneficial effects: In actual conveying, the actual carrying capacity of the upstream conveyor may fluctuate. A fluctuation value greater than or equal to the carrying capacity fluctuation threshold within a preset time indicates a relatively large fluctuation in the actual carrying capacity of the upstream conveyor. When the actual carrying capacity of the upstream conveyor fluctuates significantly, if the actual buffer volume in the buffer bin is greater than or equal to the lower buffer limit, it means that the amount of material buffered in the buffer bin meets the rated conveying capacity requirements of the downstream conveyor. In this case, there is no need to adjust the feeding speed of the feeder and the belt speed of the downstream conveyor; the feeder can be directly controlled to operate at the rated feeding volume, and the downstream conveyor can operate at the rated belt speed and rated carrying capacity, thus improving material conveying efficiency. If the actual buffer volume in the buffer bin is less than the lower buffer limit, it means that the amount of material buffered in the buffer bin is relatively small and cannot meet the rated conveying capacity requirements of the downstream conveyor. In this case, the feeding volume of the feeder and the belt speed of the downstream conveyor should be adjusted based on the actual buffer volume, the amount of material being conveyed by the downstream conveyor, and the amount of material not yet conveyed by the downstream conveyor. This allows for adjustment of the feeding speed and conveying speed according to the incoming material situation of the upstream conveyor, avoiding problems such as unstable material flow in the downstream conveyor and empty buffer bins.

[0012] In one optional implementation, the step of adjusting the feed rate of the feeder and the belt speed of the downstream conveyor based on the actual buffer quantity of the buffer bin, the amount of material being conveyed by the downstream conveyor, and the amount of material conveying system has not yet completed in this operation includes: determining whether the sum of the actual buffer quantity of the buffer bin and the amount of material being conveyed by the downstream conveyor is greater than the amount of material conveying system has not yet completed in this operation, wherein the amount of material conveying system has not yet completed in this operation is the difference between the total amount of material to be conveyed by the material conveying system and the amount of material already conveyed by the downstream conveyor; determining that the sum of the actual buffer quantity of the buffer bin and the amount of material being conveyed by the downstream conveyor is greater than or equal to the amount of material conveying system has not yet completed in this operation, then controlling the feeder to operate at the rated feed rate and the downstream conveyor to operate at the rated belt speed and rated conveying capacity until the current transportation task is completed; determining that the sum of the actual buffer quantity of the buffer bin and the amount of material being conveyed by the downstream conveyor is less than the amount of material conveying system has not yet completed in this operation, then reducing the feed rate of the feeder and lowering the belt speed of the downstream conveyor.

[0013] Beneficial effects: When the sum of the actual buffer capacity of the buffer bin and the amount of material being conveyed by the downstream conveyor is greater than or equal to the amount of material that the material conveying system has not yet completed this time, it means that the sum of the amount of material buffered in the buffer bin and the amount of material being conveyed by the downstream conveyor can meet the amount of material that the material conveying system has not yet conveyed this time. At this time, the feeder is directly controlled to operate at the rated feed rate and the downstream conveyor is controlled to operate at the rated belt speed and rated conveying capacity to ensure that the conveying task is completed in the shortest possible time. When the total amount of material to be conveyed by the material conveying system this time is reached, the feeder and the downstream conveyor can be stopped. When the sum of the actual buffer capacity of the buffer bin and the amount of material being conveyed by the downstream conveyor is less than the amount of material that the material conveying system has not yet completed this time, it indicates that the sum of the amount of material buffered in the buffer bin and the amount of material being conveyed by the downstream conveyor does not meet the amount of material that the material conveying system has not yet conveyed this time. At this time, reduce the feeding rate of the feeder and reduce the belt speed of the downstream conveyor to ensure the stability of the filling rate of the long-distance conveyor, reduce the impact of material interruption on the long-distance conveyor, and prevent uneven tension distribution of the conveyor caused by partial material interruption in the long-distance conveyor, resulting in spillage, drifting, belt vibration and other effects.

[0014] In one optional implementation, in the step of reducing the feed rate of the feeder, the feeder is controlled to feed the downstream conveyor according to the actual conveying capacity of the upstream conveyor; in the step of reducing the belt speed of the downstream conveyor, the belt speed of the downstream conveyor is controlled to decrease from the current belt speed to the target belt speed, where the target belt speed v of the downstream conveyor is... n2 =v E2 ×Q1 / Q E2 , where v E2 Q is the rated belt speed of the downstream conveyor, Q1 is the actual conveying capacity of the upstream conveyor, and QE2 This is the rated capacity of the downstream conveyor.

[0015] Beneficial effects: By reducing the belt speed of the downstream conveyor, the filling material of the downstream conveyor can be guaranteed, avoiding uneven tension distribution of the conveyor caused by material breakage, resulting in material spillage, swaying, belt vibration, etc., thus ensuring the stability of the downstream conveyor.

[0016] In one alternative implementation, in the step of controlling the belt speed of the downstream conveyor to decrease from the current belt speed to the target belt speed, the belt speed of the downstream conveyor is controlled to change from the current belt speed curve to the target belt speed.

[0017] Beneficial effects: By using a curved speed change mechanism, the impact of speed change on the downstream conveyor is reduced, thereby avoiding the problems of material spillage, swaying, and belt vibration caused by large speed change impacts.

[0018] In one optional implementation, in the step of controlling the belt speed of the downstream conveyor to change from the current belt speed curve to the target belt speed, the belt speed of the downstream conveyor is first controlled to run at the current belt speed for a preset time, then gradually reduced from the current belt speed to the target belt speed, and then continues to run at the target belt speed. The current belt speed is v. n1 The target speed is v n2 The downstream conveyor's speed change starts at time t1, and the downstream conveyor at time t... n The speed change is completed within seconds, and the speed change completion time of the downstream conveyor is t1+t. n The belt speed of the downstream conveyor is v = (v n1 +v n2 ) / 2+[(v n1 -v n2 ) / 2]*cos(π*(t-t1) / t n ), t1 <t<t1+t n .

[0019] Beneficial effects: The speed curve of the downstream conveyor changes smoothly without any sudden speed changes; the deceleration of the corresponding speed change is zero before deceleration, and gradually increases and decreases from zero to zero during the deceleration process. After the speed change is completed, it remains zero. The deceleration curve also does not have any sudden speed changes, which makes the belt speed of the downstream conveyor gradually decrease. This achieves a smooth transition in the deceleration of the speed change curve and reduces the impact of speed change.

[0020] In one optional embodiment, before the step of controlling the belt speed of the downstream conveyor to decrease from the current belt speed to the target belt speed, the material conveying control method further includes: determining whether the target belt speed to which the downstream conveyor is to be reduced is greater than 10% of its rated belt speed; if it is determined that the target belt speed to which the downstream conveyor is to be reduced is greater than 10% of its rated belt speed, then controlling the belt speed of the downstream conveyor to decrease from the current belt speed to the target belt speed; if it is determined that the target belt speed to which the downstream conveyor is to be reduced is less than or equal to 10% of its rated belt speed, then controlling the belt speed of the downstream conveyor to decrease from the current belt speed to 10% of its rated belt speed and controlling the alarm component to trigger an alarm.

[0021] Beneficial effects: When the target belt speed of the downstream conveyor is less than or equal to % of its rated belt speed, it indicates that the filling rate of the downstream conveyor cannot be guaranteed. Control the belt speed of the downstream conveyor to reduce to 10% of its rated belt speed and trigger the alarm. The operator will then make a final decision on whether to stop the machine based on the alarm signal and the feeding status of the upstream conveyor. For example, if the upstream conveyor cannot be fed for a long period of time, the operator can control the downstream conveyor to stop. If the upstream conveyor can be fed for a short period of time, the operator can control the downstream conveyor to continue running at 10% of its rated belt speed without stopping.

[0022] In one optional implementation, after controlling the belt speed of the downstream conveyor to decrease from the current belt speed to the target belt speed, the material conveying control method further includes: if the fluctuation value of the conveying volume of the upstream conveyor within a preset time is less than the conveying volume fluctuation threshold and the actual buffer volume in the buffer bin is greater than or equal to the buffer lower limit value, then the feeding volume of the feeder is increased and the belt speed of the downstream conveyor is increased.

[0023] Beneficial effects: When the fluctuation value of the transport volume of the upstream conveyor within a preset time is less than or equal to the transport volume fluctuation threshold and the actual buffer volume in the buffer bin is greater than or equal to the lower limit of the buffer volume, it indicates that the feed volume of the upstream conveyor gradually increases to the rated feed volume and the buffer bin restores the minimum buffer volume. On this basis, the upstream conveyor feeds evenly, directly increasing the feed volume of the feeder and increasing the belt speed of the downstream conveyor, thereby improving the conveying efficiency. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a material conveying system according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic flowchart of a material conveying control method according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of a specific process of a material conveying control method according to an embodiment of the present invention;

[0028] Figure 4 This is a speed change curve diagram of the belt speed of a downstream conveyor according to an embodiment of the present invention;

[0029] Figure 5 This is a speed change curve of the deceleration of a downstream conveyor according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Upstream conveyor; 2. Downstream conveyor; 3. Buffer bin; 4. Feeder; 501. First material detection piece; 502. Second material detection piece; 503. Third material detection piece; 504. Fourth material detection piece. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The following is combined Figure 1 The following describes embodiments of the present invention.

[0034] According to an embodiment of the present invention, a material conveying system is provided, comprising: an upstream conveyor 1, a downstream conveyor 2, a buffer bin 3, a feeder 4, a first material detection element 501, a second material detection element 502, and a controller. The downstream conveyor 2 is disposed downstream of the upstream conveyor 1. The buffer bin 3 has an inlet and an outlet, the inlet corresponding to the head of the upstream conveyor 1. The feeder 4 is disposed at the outlet and is located above the tail of the downstream conveyor 2. The first material detection element 501 is used to detect the actual conveying capacity of the upstream conveyor 1. The second material detection element 502 is used to detect the actual buffering capacity in the buffer bin 3. The controller is interlocked with the upstream conveyor 1, the downstream conveyor 2, and the feeder 4, and the controller is used to control the feeding rate of the feeder 4 and the belt speed of the downstream conveyor 2 according to the actual conveying capacity of the upstream conveyor 1 and the actual buffering capacity in the buffer bin 3.

[0035] The material conveying system of this embodiment has a buffer bin 3 installed at the head of the upstream conveyor 1 and the tail of the downstream conveyor 2. The buffer bin 3 can buffer the material conveyed by the upstream conveyor 1. The feeding speed is controlled by the feeder 4 at the outlet of the buffer bin 3. By feeding the downstream conveyor 2 evenly with the feeder 4, the cross-sectional area of ​​the material in the downstream conveyor can be stabilized, and the belt speed of the downstream conveyor can be dynamically adjusted, making the downstream conveyor 2 run stably, reducing energy consumption, and effectively avoiding the situation where the downstream conveyor 2 frequently switches operating conditions, has poor operating stability, low utilization rate, and increased energy consumption due to uneven feeding or material interruption from the upstream. Furthermore, the controller controls the feeding amount of the feeder 4 and the belt speed of the downstream conveyor 2 according to the actual conveying volume of the upstream conveyor 1 and the actual buffer volume in the buffer bin 3, thereby ensuring the stability of the cross-sectional area of ​​the material in the downstream conveyor 2 and avoiding phenomena such as material interruption.

[0036] In this embodiment, the downstream conveyor 2 is a long-distance conveyor, and the upstream conveyor 1 is a regular conveyor. The long-distance conveyor is equipped with a corresponding belt speed sensor to detect the belt speed. Specifically, the long-distance conveyor and the regular conveyor are preferably belt conveyors. The buffer bin 3 and the feeder 4 solve the problem of uneven feeding and material interruption in the upstream of the long-distance conveyor, which leads to unstable material flow in the long-distance conveyor, thereby avoiding the poor stability of the long-distance conveyor caused by frequent switching of working conditions.

[0037] In this embodiment, the feeder 4 is a vibrating feeder or a plate feeder. The vibrating feeder or plate feeder provides uniform material feeding to the long-distance conveyor, avoiding direct feeding of uneven material. The vibrating feeder adjusts the feeding amount by adjusting the excitation force or excitation frequency.

[0038] In this embodiment, the material conveying system further includes a third material detection element 503 and a fourth material detection element 504. The third material detection element 503 is located near the feeder 4 and is used to detect the amount of material conveyed by the feeder to the downstream conveyor 2, i.e., the feeding amount of the downstream conveyor 2. The fourth material detection element 504 is located at the head of the downstream conveyor 2 and is used to detect the amount of material that has been conveyed by the downstream conveyor 2. The controller is used to adjust the feeding amount of the feeder 4 and the belt speed of the downstream conveyor 2 according to the actual buffer amount of the buffer bin 3, the amount of material being conveyed by the downstream conveyor 2, and the amount of material that the material conveying system has not yet completed. By changing the speed of the long-distance conveyor, the operating power is reduced, the utilization rate of the downstream conveyor is improved, and the problem of increased energy consumption per ton of material is avoided. This can effectively ensure the stability of the material cross-sectional area of ​​the downstream conveyor 2 and avoid phenomena such as material interruption.

[0039] In this embodiment, the first material detection element 501, the second material detection element 502, the third material detection element 503 and the fourth material detection element 504 are all volume sensors. They can calculate the amount of material or the amount of material transported by detecting the volume of the material, which is easy to implement.

[0040] Specifically, the first material detection component 501 is a first volume sensor, located above the head of the upstream conveyor 1. It monitors the volume of material conveyed by the upstream conveyor 1 in real time and accumulates the total volume transported. The second material detection component 502 is a second volume sensor, located at the top of the buffer bin 3. It monitors the material stored in the buffer bin 3 in real time. The third material detection component 503 is a third volume sensor, located above the tail of the downstream conveyor 2 at the discharge port of the feeder 4. The material volume measured by the third volume sensor not only records the feed amount of the downstream conveyor 2 but also verifies the stability of the material cross-section of the downstream conveyor 2, monitoring for fluctuations in the cross-sectional area. The fourth material detection component 504 is a fourth volume sensor, located above the head of the downstream conveyor 2. It calculates the discharge amount of the downstream conveyor 2 based on the material volume obtained from the fourth volume sensor and handles external settlement functions.

[0041] Specifically, the first volume sensor, the second volume sensor, and the third volume sensor are mutually calibrated. The value measured by the first volume sensor is the incoming material quantity, and the value measured by the third volume sensor is the output quantity of the feeder 4. The difference between the values ​​measured by the first volume sensor and the third volume sensor is the material storage quantity in the buffer bin 3, which is mutually calibrated with the value measured by the second volume sensor. The third volume sensor and the fourth volume sensor are mutually calibrated. When the output quantity of the third volume sensor is transported to the head, it is the value of the fourth volume sensor. The amount of material being transported by the downstream conveyor 2 is the difference between the cumulative output quantity of the third volume sensor and the cumulative output quantity of the fourth volume sensor.

[0042] It should be noted that the direction of material movement refers to the direction in which the material moves toward the head of the downstream conveyor 2.

[0043] In other embodiments, the first material detection element 501, the second material detection element 502, the third material detection element 503, and the fourth material detection element 504 can also be other sensors, as long as they can detect the parameters of the material and calculate the amount of material based on those parameters.

[0044] like Figure 2 As shown, according to an embodiment of the present invention, in another aspect, a material conveying control method is provided for controlling the above-described material conveying system. The material conveying control method includes the following steps:

[0045] Obtain the actual transport volume of the upstream conveyor 1 and the actual buffer volume in the buffer bin 3 of the material conveying system;

[0046] The feeding rate of the feeder 4 and the belt speed of the downstream conveyor 2 are controlled based on the actual conveying capacity of the upstream conveyor 1 and the actual buffer capacity in the buffer bin 3.

[0047] By adjusting the feeding rate of the feeder 4 and the belt speed of the downstream conveyor 2 based on the actual conveying capacity of the upstream conveyor 1 and the actual buffer capacity in the buffer bin 3, the feeding rate of the feeder 4 is ensured to be uniform, thereby making the downstream conveyor 2 run stably, reducing energy consumption, and effectively avoiding the situation where the downstream conveyor 2 frequently switches operating conditions, has poor operating stability, low utilization rate, and increased energy consumption due to uneven feeding or material interruption from the upstream.

[0048] It should be noted that the transport volume per unit time is represented by Q, with the unit of Q being kg / s, and the volume transported per unit time is represented by Q. v Q indicates v The unit is m 3 / s, then Q=Q v ×ρ, where ρ is the density of the material, is used to integrate with respect to Q to obtain the conveying capacity or material quantity. v The volume sensors detect the volume of transported material per unit time. The data detected by the first, third, and fourth volume sensors are all the volume of transported material per unit time. The value detected by the second volume sensor is the volume of material in the buffer bin 3. The actual buffer amount in the buffer bin 3 is the product of the volume detected by the second volume sensor and the density.

[0049] Specifically, the volume transported per unit time detected by the first volume sensor is denoted by Q. v1 Let Q1 represent the actual transport volume of upstream conveyor 1 per unit time, then Q1 = Q v1 ×ρ; Q represents the volume transported per unit time detected by the third volume sensor. v3 The volume transported per unit time detected by the fourth volume sensor is represented by Q. v4 It means that for (Q) v4 -Q v3 The amount of material being conveyed by downstream conveyor 2 is obtained by integrating ρ × Q. v4 The amount of material that has been conveyed by downstream conveyor 2 is obtained by integrating ×ρ.

[0050] In this embodiment, the steps of controlling the feed rate of the feeder 4 and the belt speed of the downstream conveyor 2 based on the actual transport capacity of the upstream conveyor 1 and the actual buffer capacity in the buffer bin 3 include:

[0051] Determine whether the fluctuation value of the transport volume of upstream conveyor 1 within a preset time is greater than the transport volume fluctuation threshold;

[0052] If the fluctuation value of the transport volume of upstream conveyor 1 within a preset time period is determined to be greater than the transport volume fluctuation threshold, then it is determined whether the actual buffer volume in buffer bin 3 is greater than or equal to the lower limit of the buffer volume.

[0053] If the actual buffer amount in buffer bin 3 is determined to be greater than or equal to the lower limit of buffer, then the feeder 4 is controlled to operate at the rated feed amount and the downstream conveyor 2 is controlled to operate at the rated belt speed and rated conveying capacity.

[0054] If the actual buffer quantity in buffer bin 3 is determined to be less than the lower limit of buffer quantity, then the feed rate of feeder 4 and the belt speed of downstream conveyor 2 are adjusted according to the actual buffer quantity in buffer bin 3, the amount of material being conveyed by downstream conveyor 2, and the amount of material conveying that the material conveying system has not yet completed.

[0055] During actual conveying, the actual conveying capacity of upstream conveyor 1 may fluctuate. A fluctuation value greater than or equal to the fluctuation threshold of upstream conveyor 1 within a preset time period indicates a relatively large fluctuation in the actual conveying capacity of upstream conveyor 1. When the actual conveying capacity of upstream conveyor 1 fluctuates significantly, if the actual buffer quantity in buffer bin 3 is greater than or equal to the lower buffer limit, it means that the amount of material buffered in buffer bin 3 meets the rated conveying capacity requirements of the downstream conveyor. In this case, there is no need to adjust the feeding speed of feeder 4 or the belt speed of downstream conveyor 2; simply control feeder 4 to operate at the rated feeding quantity and downstream conveyor 2... Operating at the rated belt speed and rated conveying capacity improves material conveying efficiency. If the actual buffer volume in buffer bin 3 is less than the lower limit of buffer volume, it means that the amount of material buffered in buffer bin 3 is relatively small and cannot meet the rated conveying capacity requirements of the downstream conveyor. At this time, the feeding rate of feeder 4 and the belt speed of downstream conveyor 2 are adjusted according to the actual buffer volume of buffer bin 3, the amount of material being conveyed by downstream conveyor 2, and the amount of material that downstream conveyor 2 has not yet completed. This allows for adjustment of the feeding speed and conveying speed according to the material arrival situation of the upstream conveyor, which can avoid problems such as unstable material flow in downstream conveyor 2 and empty buffer bins.

[0056] Specifically, the threshold for fluctuation in transport volume can be set to 5% of the rated transport volume, etc.

[0057] It should be noted that the upstream conveyor 1 can be loaded with materials by excavators, bulldozers, etc. The total amount of material to be conveyed by the material conveying system this time is the value entered by the operator on the display screen.

[0058] In this embodiment, if the fluctuation value of the conveying capacity of the upstream conveyor 1 within a preset time is less than or equal to the conveying capacity fluctuation threshold, then the feeder 4 is controlled to operate at the rated feeding capacity and the downstream conveyor 2 is controlled to operate at the rated belt speed and rated conveying capacity. The fact that the fluctuation value of the conveying capacity of the upstream conveyor 1 within the preset time is less than or equal to the conveying capacity fluctuation threshold means that the actual conveying capacity fluctuation of the upstream conveyor 1 is not significant. When the actual conveying capacity fluctuation of the upstream conveyor 1 is not significant, it indicates that the feeding is uniform, and the feeder 4 is directly controlled to operate at the rated feeding capacity and the downstream conveyor 2 is controlled to operate at the rated belt speed and rated conveying capacity, thereby improving material conveying efficiency.

[0059] To ensure the filling rate of the long-distance conveyor, reduce the impact of material interruption on the long-distance conveyor, and prevent uneven tension distribution of the conveyor caused by partial material interruption, resulting in spillage, drifting, belt vibration, etc., in this embodiment, if the actual buffer amount in the buffer bin 3 is determined to be less than the lower limit of the buffer, the steps of adjusting the feed rate of the feeder 4 and the belt speed of the downstream conveyor 2 according to the actual buffer amount in the buffer bin 3, the amount of material being conveyed by the downstream conveyor 2, and the amount of material that the material conveying system has not yet completed include:

[0060] Determine whether the sum of the actual buffer quantity of buffer bin 3 and the quantity of material being conveyed by downstream conveyor 2 is greater than or equal to the quantity of material conveying system that has not yet been completed this time. The quantity of material conveying system that has not yet been completed this time is the difference between the total amount of material to be conveyed by material conveying system this time and the amount of material already conveyed by downstream conveyor 2.

[0061] If the sum of the actual buffer capacity of buffer bin 3 and the material being conveyed by downstream conveyor 2 is greater than or equal to the material conveying system’s unfinished conveying capacity, then control feeder 4 to operate at the rated feeding capacity and downstream conveyor 2 to operate at the rated belt speed and rated conveying capacity until the current conveying task is completed.

[0062] If the sum of the actual buffer capacity of buffer bin 3 and the amount of material being conveyed by downstream conveyor 2 is less than the amount of material conveying system has not yet completed this time, then reduce the feed rate of feeder 4 and reduce the belt speed of downstream conveyor 2.

[0063] The difference between the total amount of material to be conveyed by the material conveying system and the amount of material already conveyed by the downstream conveyor 2 refers to the amount of material that the material conveying system has not yet completed this time. When the sum of the actual buffer capacity of the buffer bin 3 and the amount of material being conveyed by the downstream conveyor 2 is greater than or equal to the amount of material that the material conveying system has not yet completed this time, it means that the sum of the amount of material buffered by the buffer bin 3 and the amount of material being conveyed by the downstream conveyor 2 can meet the amount of material that the material conveying system has not yet conveyed this time. At this time, the feeder 4 is directly controlled to operate at the rated feed rate and the downstream conveyor 2 is controlled to operate at the rated belt speed and rated conveying capacity to ensure that the conveying task is completed in the shortest possible time. When the total amount of material to be conveyed by the material conveying system this time is reached, the feeder 4 and the downstream conveyor 2 are controlled to stop. When the sum of the actual buffer capacity of buffer bin 3 and the amount of material being conveyed by downstream conveyor 2 is less than the amount of material conveying system has not yet completed this time, it indicates that the sum of the amount of material buffered in buffer bin 3 and the amount of material being conveyed by downstream conveyor 2 does not meet the amount of material that the material conveying system has not yet conveyed this time. At this time, reduce the feeding amount of feeder 4 and reduce the belt speed of downstream conveyor 2 to ensure the stability of the filling rate of long-distance conveyor, reduce the impact of material interruption on long-distance conveyor, and prevent uneven tension distribution of conveyor caused by partial material interruption in long-distance conveyor, resulting in spillage, drifting, belt vibration and other effects.

[0064] In this embodiment, in the step of reducing the feeding amount of the feeder 4, the feeder 4 is controlled to feed the downstream conveyor 2 according to the actual conveying capacity of the upstream conveyor 1. The feeding amount of the feeder 4 is consistent with the actual conveying capacity of the upstream conveyor 1, so that the feeding speed of the feeder 4 matches the belt speed of the upstream conveyor 1, and the feeding interruption phenomenon is avoided.

[0065] In this embodiment, in the step of reducing the belt speed of the downstream conveyor 2, the belt speed of the downstream conveyor 2 is controlled to decrease from the current belt speed to the target belt speed, and the target belt speed v of the downstream conveyor 2 is... n2 =v E2 ×Q1 / Q E2 , where v E2 Q is the rated belt speed of downstream conveyor 2, Q1 is the actual conveying capacity of upstream conveyor 1, and Q... E2 This is the rated conveying capacity of downstream conveyor 2. By reducing the belt speed of downstream conveyor 2, the filling material of downstream conveyor 2 can be guaranteed, avoiding uneven tension distribution of the conveyor caused by material breakage, resulting in material spillage, swaying, belt vibration, etc., thus ensuring the stability of downstream conveyor 2.

[0066] In this embodiment, in the step of controlling the belt speed of the downstream conveyor 2 to decrease from the current belt speed to the target belt speed, the belt speed of the downstream conveyor 2 is controlled to change from the current belt speed curve to the target belt speed. By changing the speed curve, the speed change impact of the downstream conveyor 2 is reduced, thereby avoiding large speed change impacts that could lead to material spillage, swaying, and belt vibration.

[0067] In this embodiment, as Figure 4 and Figure 5 As shown, in the step of controlling the belt speed of downstream conveyor 2 to change from the current belt speed curve to the target belt speed, the belt speed of downstream conveyor 2 first runs at the current belt speed for a preset time, then gradually decreases from the current belt speed to the target belt speed, and then continues to run at the target belt speed. The current belt speed is v. n1 The target speed is v n2 The downstream conveyor 2's speed change starts at time t1, and the downstream conveyor 2 at time t... n The speed change is completed within seconds, and the speed change completion time of downstream conveyor 2 is t1+t. n The belt speed of downstream conveyor 2 is v = (v n1 +v n2 ) / 2+[(v n1 -v n2 ) / 2]*cos(π*(t-t1) / t n ), t1 <t<t1+t n The deceleration of the downstream conveyor 2's speed change curve is zero before deceleration. During deceleration, the deceleration gradually increases from zero and then gradually decreases back to zero. After the speed change is complete, it remains zero. The deceleration curve has no abrupt changes, resulting in a gradual decrease in the belt speed of the downstream conveyor 2. This achieves a smooth transition in the deceleration of the speed change curve, minimizing speed change impact. The downstream conveyor 2 first runs at the current belt speed for a preset time, then gradually decreases from the current belt speed to the target belt speed, and then continues running at the target belt speed. The deceleration of the downstream conveyor 2 is zero before deceleration, gradually increases from zero and then gradually decreases back to zero during deceleration, and remains zero after the speed change is complete. The deceleration a = [(v n1 -v n2 ) / 2]*sin(π*(t-t1) / t n )*π / t n The following example illustrates that when v n1 =4m / s and v n2 When the speed is 2 m / s, the belt speed is 4 m / s from 0 to 10 s, gradually decreases from 4 m / s to 2 m / s from 10 s to 50 s, and remains at 2 m / s from 50 s to 60 s. The speed change process is from 10 s to 50 s. From 0 to 10 s, the belt speed remains constant and the deceleration is 0. From 10 to 50 s, the belt speed gradually decreases from 4 m / s to 2 m / s with continuous deceleration. From 50 to 60 s, the speed change is complete, the belt speed remains constant, and the deceleration is 0. The speed change curve is smooth, and there are no abrupt changes in acceleration.

[0068] In this embodiment, before the step of reducing the belt speed of the downstream conveyor 2 from the current belt speed to the target belt speed, the material conveying control method further includes:

[0069] Determine whether the target belt speed to which downstream conveyor 2 needs to be reduced is greater than 10% of its rated belt speed;

[0070] If the target belt speed to which the downstream conveyor 2 needs to be reduced is determined to be greater than 10% of its rated belt speed, then the belt speed of the downstream conveyor 2 will be reduced from the current belt speed to the target belt speed.

[0071] If the target belt speed to be reduced to by the downstream conveyor 2 is determined to be less than or equal to 10% of its rated belt speed, then the belt speed of the downstream conveyor 2 will be reduced from its current belt speed to 10% of its rated belt speed, and the alarm component will be activated.

[0072] When the target belt speed of downstream conveyor 2 is less than or equal to 10% of its rated belt speed, it indicates that the filling rate of downstream conveyor 2 cannot be guaranteed. The belt speed of downstream conveyor 2 is controlled to be reduced to 10% of its rated belt speed, and the alarm component is activated. The operator makes the final decision on whether to stop the machine based on the alarm signal and the feeding status of upstream conveyor 1. For example, if upstream conveyor 1 cannot be fed for a long period of time, the operator can control downstream conveyor 2 to stop. If upstream conveyor 1 can be fed for a short period of time, the operator can control downstream conveyor 2 to continue running at 10% of its rated belt speed.

[0073] In this embodiment, after controlling the downstream conveyor's belt speed to decrease from the current belt speed to the target belt speed, the material conveying control method further includes: if the fluctuation value of the upstream conveyor's conveying capacity within a preset time is less than or equal to the conveying capacity fluctuation threshold and the actual buffer capacity in the buffer bin is greater than or equal to the buffer lower limit, then the feed rate of the feeder is increased and the belt speed of the downstream conveyor is increased. When the fluctuation value of the upstream conveyor's conveying capacity within a preset time is less than or equal to the conveying capacity fluctuation threshold and the actual buffer capacity in the buffer bin is greater than or equal to the buffer lower limit, it indicates that the feed rate of the upstream conveyor gradually increases to the rated feed rate, and the buffer bin restores the minimum buffer capacity. On this basis, the upstream conveyor feeds uniformly, directly increasing the feed rate of the feeder and increasing the belt speed of the downstream conveyor, thereby improving conveying efficiency.

[0074] In this embodiment, the steps of increasing the feed rate of the feeder and increasing the belt speed of the downstream conveyor involve controlling the feeder to operate at the rated feed rate and controlling the belt speed of the downstream conveyor to change from the current belt speed curve to the rated belt speed. Specifically, the belt speed of the downstream conveyor is controlled to first run at the current belt speed for a preset time, then gradually increase from the current belt speed to the rated belt speed, and then continue to run at the rated belt speed. The speed increase process is similar to the speed decrease process and will not be described in detail here.

[0075] In this embodiment, the material conveying control method further includes:

[0076] Determine whether the amount of material already conveyed by downstream conveyor 2 has reached the total conveying capacity of the material conveying system in this transport;

[0077] When the amount of material already conveyed by downstream conveyor 2 reaches the total conveying volume of the material conveying system for this transport, control feeder 4, upstream conveyor 1, and downstream conveyor 2 to stop.

[0078] If it is determined that the amount of material already transported by downstream conveyor 2 has not reached the total amount of material transported by the material conveying system this time, then the actual transport volume of upstream conveyor 1, the actual buffer volume in the buffer bin, the amount of material being transported by downstream conveyor 2, and the amount of material already transported by downstream conveyor 2 will continue to be obtained.

[0079] When the amount of material transported by downstream conveyor 2 reaches the total transport volume of the material conveying system for this transport, it indicates that the transport has been completed. At this time, feeder 4, upstream conveyor 1, and downstream conveyor 2 can be stopped. If the next transport is to be carried out, feeder 4, upstream conveyor 1, and downstream conveyor 2 should be controlled to continue running.

[0080] In this embodiment, the rated capacity of the upstream conveyor 1 is Q. E1 The actual transport capacity is Q1, and the rated belt speed is v. E1 The actual belt speed is v1; the rated capacity of the long-distance conveyor is Q. E2 The actual transport capacity is Q2, and the rated belt speed is v. E2 The actual belt speed is v2, and during normal transportation, Q1 = Q2.

[0081] The following is combined Figure 3 The control logic of the material conveying control method is explained:

[0082] 1. Determine the total transport volume M of the material conveying system for this transport;

[0083] 2. Control the start of the long-distance conveyor, upstream conveyor 1, vibrating feeder or plate feeder, and buffer the material in buffer bin 3;

[0084] 3. When it is detected that the flow rate Q1 of the upstream conveyor 1 fluctuates significantly and the amount of material in the buffer bin 3 is not less than the lower limit of the normal buffer material amount, the feeder 4 is controlled to feed material to the long-distance conveyor according to the rated feed rate, and the long-distance conveyor is controlled to operate at the rated belt speed and rated flow rate.

[0085] 4. When a significant fluctuation is detected in the conveying capacity Q1 of upstream conveyor 1 and the material quantity in buffer bin 3 is less than the lower limit of the normal buffer material quantity, the material quantity following program is triggered. The objectives of the material quantity following program are: to meet the filling rate of the long-distance conveyor, reduce the impact of uneven material flow on the long-distance conveyor, and prevent uneven tension distribution of the conveyor caused by partial material interruption in the long-distance conveyor, resulting in material spillage, drifting, belt vibration, and other effects.

[0086] Specifically, when the amount of material in buffer bin 3 + the amount of material being transported on the long-distance conveyor is greater than or equal to the total conveying amount M - the amount of material that has been transported by the long-distance conveyor, the feeder 4 is controlled to feed material to the long-distance conveyor according to the rated feeding amount, and the long-distance conveyor is controlled to operate according to the rated belt speed and rated conveying capacity.

[0087] When the amount of material in buffer bin 3 plus the amount of material being transported on the long-distance conveyor is less than the total conveying volume M minus the amount of material already transported by the long-distance conveyor, the feeder 4 is controlled to feed material onto the long-distance conveyor according to the feeding rate Q1. Simultaneously, the long-distance conveyor triggers its intelligent speed regulation process, initiating a curved speed change, with the belt speed becoming v. E2 ×Q1 / Q E2 To ensure that the filling rate of the long-distance conveyor remains constant; the current operating belt speed of the long-distance conveyor is v. n1 The target speed is v n2 The shift starts at time t1, and at time t n If the change is completed within seconds, then the speed change completion time is t1+t. n The belt speed of downstream conveyor 2 is v = (v n1 +v n2 ) / 2+[(v n1 -v n2 ) / 2]*cos(π*(t-t1) / t n ), t1 <t<t1+t n .

[0088] When the belt speed of a long-distance conveyor decreases to the rated belt speed v E1 When the filling rate reaches 10%, the belt speed will no longer decrease. If the filling rate of the long-distance conveyor cannot be guaranteed at this point, the long-distance conveyor will issue an alarm signal, and the control system will make the final decision on whether to stop the machine.

[0089] By changing the speed of the long-distance conveyor, the stability of the cross-sectional area of ​​the conveyed material is ensured. This solves the problem of unstable material flow caused by uneven feeding or material interruption upstream, thus avoiding poor stability due to frequent switching of operating conditions and preventing long-term high-power operation when upstream feeding is unstable. The speed change also reduces operating power, addressing the issue of increased energy consumption per ton of material. Furthermore, the speed change avoids frequent switching of operating conditions and the occurrence of special operating conditions, allowing for a reduction in the specifications of the long-distance conveyor and thus lowering investment costs. The speed curve of the downstream conveyor 2 is smooth, without any abrupt speed changes. The deceleration of the downstream conveyor 2 is zero before deceleration, gradually increases from zero and then gradually decreases back to zero during deceleration, remaining constant at zero after the speed change. The deceleration curve also lacks abrupt changes, achieving a smooth transition in both belt speed and deceleration with minimal speed change impact.

[0090] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A material conveying control method, characterized in that, For controlling a material conveying system, the material conveying system comprising: Upstream conveyor (1); The downstream conveyor (2) is located downstream of the upstream conveyor (1); The buffer compartment (3) has an inlet and an outlet, the inlet corresponding to the head of the upstream conveyor (1); A feeder (4) is provided at the discharge port, and the feeder (4) is located above the tail of the downstream conveyor (2); The first material detection component (501) is used to detect the actual transport volume of the upstream conveyor (1); The second material detection component (502) is used to detect the actual amount of buffer material in the buffer bin (3); The controller is interlocked with the upstream conveyor (1), the downstream conveyor (2), and the feeder (4). The controller is used to control the feeding amount of the feeder (4) and the belt speed of the downstream conveyor (2) according to the actual conveying amount of the upstream conveyor (1) and the actual buffer amount in the buffer bin (3). The material conveying system further includes a third material detection element (503) and a fourth material detection element (504). The third material detection element (503) is located near the feeder (4) and is used to detect the amount of material conveyed by the feeder (4) to the downstream conveyor (2). The fourth material detection element (504) is located at the head of the downstream conveyor (2) and is used to detect the amount of material that the downstream conveyor (2) has finished conveying. The controller is used to control the feeding amount of the feeder (4) and the belt speed of the downstream conveyor (2) according to the actual buffer amount of the buffer bin (3), the amount of material being conveyed by the downstream conveyor (2), and the amount of conveying that the material conveying system has not yet completed. The material conveying control method includes the following steps: Obtain the actual transport volume of the upstream conveyor (1) and the actual buffer volume in the buffer bin (3) of the material conveying system; Determine whether the fluctuation value of the transport volume of the upstream conveyor (1) within a preset time is greater than the transport volume fluctuation threshold; If the fluctuation value of the transport volume of the upstream conveyor (1) within a preset time period is determined to be greater than the transport volume fluctuation threshold, it is then determined whether the actual buffer volume in the buffer bin (3) is greater than or equal to the lower limit of the buffer volume. If the actual buffer quantity in the buffer bin (3) is determined to be greater than or equal to the lower limit of the buffer, then the feeder (4) is controlled to operate at the rated feed quantity and the downstream conveyor (2) is controlled to operate at the rated belt speed. If the actual buffer quantity in the buffer bin (3) is determined to be less than the lower limit of the buffer, the feeding quantity of the feeder (4) and the belt speed of the downstream conveyor (2) are adjusted according to the actual buffer quantity of the buffer bin (3), the amount of material being conveyed by the downstream conveyor (2) and the amount of material conveying that the material conveying system has not yet completed this time.

2. The material conveying control method according to claim 1, characterized in that, If the actual buffer quantity in the buffer bin (3) is determined to be less than the lower limit of the buffer, then the steps of adjusting the feed rate of the feeder (4) and the belt speed of the downstream conveyor (2) according to the actual buffer quantity of the buffer bin (3), the amount of material being conveyed by the downstream conveyor (2), and the amount of material conveying that the material conveying system has not yet completed this time include: Determine whether the sum of the actual buffer quantity of the buffer bin (3) and the material quantity being conveyed by the downstream conveyor (2) is greater than or equal to the material conveying system's current uncompleted conveying quantity, wherein the material conveying system's current uncompleted conveying quantity is the difference between the total amount of material to be conveyed by the material conveying system and the amount of material already conveyed by the downstream conveyor (2); If the sum of the actual buffer quantity of the buffer bin (3) and the material quantity being conveyed by the downstream conveyor (2) is greater than or equal to the material conveying system’s current uncompleted conveying quantity, then the feeder (4) is controlled to operate at the rated feed quantity and the downstream conveyor (2) is controlled to operate at the rated belt speed and rated conveying quantity until the current conveying task is completed; If the sum of the actual buffer quantity of the buffer bin (3) and the amount of material being conveyed by the downstream conveyor (2) is less than the amount of material conveying that the material conveying system has not yet completed, then reduce the feeding amount of the feeder (4) and reduce the belt speed of the downstream conveyor (2).

3. The material conveying control method according to claim 2, characterized in that, In the step of reducing the feeding amount of the feeder (4), the feeder (4) is controlled to feed the downstream conveyor (2) according to the actual conveying capacity of the upstream conveyor (1); In the step of reducing the belt speed of the downstream conveyor (2), the belt speed of the downstream conveyor (2) is controlled to decrease from the current belt speed to the target belt speed. v n2 = v E2 ×Q1 / Q E2 ,in, v E2 Q is the rated belt speed of the downstream conveyor (2), Q1 is the actual conveying capacity of the upstream conveyor (1), and Q E2 The rated capacity of the downstream conveyor (2) is given.

4. The material conveying control method according to claim 3, characterized in that, In the step of controlling the belt speed of the downstream conveyor (2) to decrease from the current belt speed to the target belt speed, the belt speed of the downstream conveyor (2) is controlled to change from the current belt speed curve to the target belt speed.

5. The material conveying control method according to claim 4, characterized in that, In the step of controlling the belt speed of the downstream conveyor (2) to change from the current belt speed curve to the target belt speed, the downstream conveyor (2) is controlled to first run at the current belt speed for a preset time, then gradually decrease from the current belt speed to the target belt speed, and then continue to run at the target belt speed. The current belt speed is... v n1 The target belt speed is v n2 The downstream conveyor (2) starts changing speed at time t1, and the downstream conveyor (2) at time t n The speed change is completed within seconds, and the speed change completion time of the downstream conveyor (2) is t1+t. n The belt speed of the downstream conveyor (2) v =( v n1 + v n2 ) / 2+[( v n1 - v n2 ) / 2]*cos(π*(t-t1) / t n ), t1 <t<t1+t n .

6. The material conveying control method according to claim 3, characterized in that, Prior to the step of controlling the belt speed of the downstream conveyor (2) to decrease from the current belt speed to the target belt speed, the material conveying control method further includes: Determine whether the target belt speed to which the downstream conveyor (2) needs to be reduced is greater than 10% of its rated belt speed; If the target belt speed to which the downstream conveyor (2) is to be reduced is determined to be greater than 10% of its rated belt speed, then the belt speed of the downstream conveyor (2) is controlled to be reduced from the current belt speed to the target belt speed. If the target belt speed to which the downstream conveyor (2) is to be reduced is less than or equal to 10% of its rated belt speed, then the belt speed of the downstream conveyor (2) is controlled to be reduced from the current belt speed to 10% of its rated belt speed and the alarm component is controlled to trigger an alarm.

7. The material conveying control method according to claim 4, characterized in that, After the step of controlling the belt speed of the downstream conveyor (2) to decrease from the current belt speed to the target belt speed, the material conveying control method further includes: If the fluctuation value of the transport volume of the upstream conveyor (1) within a preset time is less than the transport volume fluctuation threshold and the actual buffer volume in the buffer bin (3) is greater than or equal to the buffer lower limit, then the feed volume of the feeder (4) is increased and the belt speed of the downstream conveyor (2) is increased.

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