Semi-automatic material handling control method for bulk ore blending and reclaiming machine

Abstract

This invention provides a semi-automatic material handling control method for a bulk ore blending and reclaiming machine, relating to the field of material reclaiming machine technology. The method includes: acquiring flow rate setpoints, pressure setpoints, rotation speed, and operating modes, including pressure control mode and flow rate control mode. The material handling flow rate and bucket wheel working pressure are monitored separately. In pressure control mode, the pressure setpoint remains unchanged. In flow rate control mode, the pressure setpoint is adjusted based on the material handling flow rate, bucket wheel working pressure, flow rate setpoint, and operating mode. A PID instruction is invoked and its basic setpoint is tuned, where the control variable parameter is rotation speed, and the process variable parameter is bucket wheel working pressure. The rotation speed is adjusted using the PID instruction to bring the bucket wheel working pressure to the pressure setpoint. This achieves refined automatic control of the bulk ore handling flow rate by the material reclaiming machine's PLC, significantly reducing the operational difficulty of blending and reclaiming.

Description

Technical Field

[0001] This invention relates to the field of material handling equipment, and in particular to a semi-automatic material handling control method for a bulk ore mixing and handling machine. Background Technology

[0002] In manufacturing, transportation, and metallurgical industries, bucket wheel reclaimers are primary equipment for loading and mixing bulk materials. Bucket wheel reclaimers generally operate using a rotary feeding method: the reclaimer's cantilever reciprocates on the surface of the material stack, while the bucket wheel at the front of the cantilever rotates to feed the material, conveying it to the reclaimer's cantilever conveyor belt. Bucket wheel reclaimers can be programmed with Proportional-Integral-Differential (PID) instructions via a PLC. By adjusting the rotational speed (CV) as the control variable, the feed rate (SV) is directly controlled. This control method is primarily suitable for bulk materials such as coal and grain, which have low density, low resistance, and stable operation. The feed rate is essentially linearly proportional to the bucket wheel's working pressure, making the PID control system relatively simple.

[0003] When bucket wheel reclaimers operate on bulk ore, using PID control to regulate material flow faces the following challenges: The resistance of the ore material to the bucket wheel is significant and unstable. For different types of ore with varying densities or moisture contents, such as lumps, powders, and pellets, the bucket wheel load will fluctuate considerably even with the same reclaiming flow rate. The direct proportionality between reclaiming flow rate and bucket wheel working pressure exists only in a few cases where material resistance is uniform, and the proportionality coefficient varies with different reclaiming angles. In winter, frozen lumps are common in bulk ore stacks, exacerbating the fluctuations in bucket wheel load during operation. To facilitate feeding, the reclaimer bucket wheel is typically set at a certain tilt angle. The different feeding directions—left-to-right and right-to-left—also lead to significant changes in the bucket wheel working pressure. Due to the large angle of repose, high stacks, and interconnected peaks and valleys of material in bulk ore, coupled with the significant inertia of the reclaimer as heavy machinery, simple PID control can easily cause the reclaimer's bucket wheel to rapidly collide with the material bag, leading to overload and impacting all related equipment. The belt scale used to provide material flow feedback is typically tens of meters or more away from the bucket wheel's feeding point. The lag in the feedback signal, combined with the reclaimer's inertia, increases the difficulty of obtaining the pressure-flow relationship.

[0004] This means that when the reclaimer is used to blend bulk ore, the PLC's PID instructions cannot be used to adjust the material flow rate in a timely and stable manner. To ensure equipment safety, blending accuracy, and operational efficiency, operators must manually adjust the rotation speed continuously and maintain a high level of attention to control the material flow rate. During blending operations, the reclaimer typically needs to run continuously day and night, resulting in high labor intensity, requiring considerable mental and physical effort, and the blending results are easily affected by improper operation. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a semi-automatic material handling control method for a bulk ore mixing and reclaiming machine to solve the above problems.

[0006] To achieve the above objectives, this invention provides a semi-automatic material handling control method for a bulk ore blending and reclaiming machine, comprising the following steps: acquiring flow rate setpoints, pressure setpoints, rotation speed, and operating mode, including pressure control mode and flow rate control mode. The material handling flow rate and bucket wheel working pressure are monitored separately. In pressure control mode, the pressure setpoint remains unchanged; in flow rate control mode, the pressure setpoint is adjusted based on the material handling flow rate, bucket wheel working pressure, flow rate setpoint, and operating mode. A PID instruction is invoked and its base setpoint is tuned, where the control variable parameter is rotation speed, and the process variable parameter is bucket wheel working pressure. The rotation speed is adjusted using the PID instruction to bring the bucket wheel working pressure up to the pressure setpoint.

[0007] Compared with existing technologies, the advantages of this invention are as follows: It establishes a relationship between the material handling flow rate and the bucket wheel working pressure, and monitors both in real time. To achieve the set flow rate value, the pressure setpoint is continuously adjusted. Then, the rotation speed is adjusted via PID instructions to ensure the bucket wheel working pressure reaches the set pressure value, thereby achieving the set material handling flow rate. By using PLC control logic in conjunction with PID instructions, a semi-automatic operation mode for the material reclaimer is developed, enabling precise automatic control of the handling flow rate of bulk ore by the material reclaimer's PLC, significantly reducing the operational difficulty of mixing and handling materials.

[0008] Furthermore, it also includes monitoring the operation of the reclaimer. When the reclaimer operates abnormally, the rotation speed is adjusted. Specifically, this involves acquiring the reclaimer's flow rate limit, bucket wheel pressure limit, bucket wheel rotation cycle, rotation boundary angle, sliding angle, and bucket wheel rated working pressure. The sliding angle is the angle at which the reclaimer's cantilever slides from its maximum rotation speed to its inertial stop. When the reclaimed flow rate exceeds the flow rate limit, or the bucket wheel working pressure exceeds the bucket wheel pressure limit, or the bucket wheel working pressure exceeds 1.4 times the pressure setting value, the reclaimer is determined to be in an abnormal state, and the cantilever is controlled to stop rotating. The duration and number of triggers of the abnormal state are monitored. When the duration of the abnormal state exceeds one bucket wheel rotation cycle or the abnormal state is triggered twice consecutively, the bucket wheel is controlled... Stop the operation and exit the semi-automatic control mode; monitor the cantilever slewing angle, calculate the angle difference between the cantilever slewing angle and the slewing boundary angle, and reduce the slewing speed when the angle difference is less than the sliding angle until the cantilever slewing angle reaches the slewing boundary angle or a signal to stop the current slewing direction is received, at which point the slewing speed is reduced to zero; calculate the oscillation amplitude of the bucket wheel working pressure, and if the oscillation amplitude of the bucket wheel working pressure is continuously greater than 50% of the rated working pressure of the bucket wheel within one bucket wheel rotation cycle, reduce the slewing speed by 50%; if the bucket wheel working pressure is continuously greater than 110% of the pressure setting value or less than 90% of the pressure setting value within one bucket wheel rotation cycle, adjust the slewing speed until the bucket wheel working pressure is greater than or equal to 90% of the pressure setting value and less than or equal to 110% of the pressure setting value.

[0009] Furthermore, the calculation of the bucket wheel working pressure oscillation amplitude specifically involves: obtaining the maximum and minimum values ​​of the bucket wheel working pressure within a bucket wheel working pressure fluctuation cycle; calculating the difference between the maximum and minimum values, which is the bucket wheel working pressure oscillation amplitude.

[0010] Furthermore, if the working pressure of the bucket wheel remains greater than 110% of the pressure setting value or less than 90% of the pressure setting value within one bucket wheel rotation cycle, the rotation speed is adjusted until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value and less than or equal to 110% of the pressure setting value. Specifically, if the working pressure of the bucket wheel remains greater than 110% of the pressure setting value within one bucket wheel rotation cycle, the rotation speed is continuously reduced to 90% of the rotation speed at the end of the previous adjustment cycle, with an adjustment cycle of 1 second, until the working pressure of the bucket wheel is less than or equal to 110% of the pressure setting value; if the working pressure of the bucket wheel remains less than 90% of the pressure setting value within one bucket wheel rotation cycle... The adjustment cycle is then set at one bucket wheel rotation cycle, continuously increasing the rotation speed to 120% of the rotation speed at the end of the previous adjustment cycle until the bucket wheel working pressure is greater than or equal to 90% of the pressure setting value. If the bucket wheel working pressure is consistently less than 60% of the pressure setting value within one bucket wheel rotation cycle, the adjustment cycle is then set at 1 second, continuously increasing the rotation speed to 120% of the rotation speed at the end of the previous adjustment cycle until the bucket wheel working pressure is greater than or equal to 60% of the pressure setting value. Then, the adjustment cycle is set at one bucket wheel rotation cycle again, continuously increasing the rotation speed to 120% of the rotation speed at the end of the previous adjustment cycle until the bucket wheel working pressure is greater than or equal to 90% of the pressure setting value.

[0011] Furthermore, the basic tuning value of the PID instruction is specifically configured as follows: the basic tuning value of the PID instruction is configured for both rotation directions. The basic tuning value of the PID instruction for both rotation directions is configured according to the following steps: when the reclaimer is operating in the middle area of ​​the stack of different types of materials, the PID parameter set is tested under the rated load of the reclaimer using the PID parameter tuning method in a single rotation direction, and the parameter fluctuation range is recorded; based on the parameter fluctuation range of each parameter set, if there is a parameter set applicable to more than 80% of the working conditions, the parameter set applicable to more than 80% of the working conditions is used as the basic tuning value; otherwise, the parameter sets corresponding to different types of materials are recorded as the basic tuning values ​​for different types of materials.

[0012] Further, the adjustment of the pressure setting value based on the material intake flow rate, bucket wheel working pressure, flow rate setting value, and operating mode specifically involves: calculating the average value of the first material intake flow rate and the average value of the bucket wheel pressure within the latest bucket wheel rotation cycle, and the average value of the second material intake flow rate within the latest two bucket wheel rotation cycles, based on the material intake flow rate and the bucket wheel working pressure; calculating the linearity coefficient between the material intake flow rate and the bucket wheel working pressure within the latest bucket wheel rotation cycle based on the average value of the first material intake flow rate and the average value of the bucket wheel pressure; and adjusting the pressure setting value based on the material intake flow rate being greater than 1.4 times the flow rate setting value or the material intake flow rate being greater than 1.2 times the flow rate setting value within a consecutive bucket wheel rotation cycle. At the same time, the maximum working pressure of the bucket wheel in the latest bucket wheel rotation cycle is obtained, and the pressure set value is compared with the average bucket wheel pressure and the maximum working pressure of the bucket wheel respectively. If the average bucket wheel pressure is less than or equal to 1.3 times the pressure set value or the maximum working pressure of the bucket wheel is less than or equal to 1.5 times the pressure set value, the pressure set value is adjusted according to the operation mode. If the material flow rate is less than 0.8 times the flow rate set value in a consecutive bucket wheel rotation cycle, or the first average material flow rate is less than 0.8 times the flow rate set value, or the second average material flow rate is less than the flow rate set value, the pressure set value is adjusted according to the linearity coefficient.

[0013] Further, the calculation of the linear coefficient between the material intake flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle based on the average value of the first material intake flow rate and the average value of the bucket wheel pressure specifically involves: acquiring and recording the monitored material intake flow rate and bucket wheel working pressure in the latest bucket wheel rotation cycle with a 1-second acquisition period; and calculating the linear coefficient between the material intake flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle according to the following formula: , where R 2 P are linear coefficients. i Let Pv be the working pressure of the i-th bucket wheel, Pv be the average bucket wheel pressure, Rate1 be the average first material handling flow rate, and R be the average flow rate. i Let i be the material flow rate for the i-th material intake, where i = 1, 2, ..., n.

[0014] Furthermore, after calculating the linear coefficient between the material reclaiming flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle based on the first average material reclaiming flow rate and the average bucket wheel pressure, the process also includes: obtaining the rated operating flow rate of the reclaimer; comparing the first average material reclaiming flow rate with the rated operating flow rate; when the first average material reclaiming flow rate is greater than 70% of the rated operating flow rate and the linear coefficient is greater than or equal to 0.8, it is determined that the first average material reclaiming flow rate and the average bucket wheel pressure satisfy a positive proportional relationship, and the relationship between the first average material reclaiming flow rate and the average bucket wheel pressure is calculated according to the linear regression equation, i.e., Rate1 = k × Pv + b; where, b = Rate1 - k × Pv.

[0015] Furthermore, the operating modes also include a low-material-head priority mode and an efficiency-priority mode. The adjustment of the pressure setting value according to the operating mode is as follows: If in low-material-head priority mode, the pressure setting value is adjusted to the average bucket wheel pressure / 1.2. The pressure setting value is not adjusted again within two bucket wheel rotation cycles after the initial adjustment, and is not increased again within five bucket wheel rotation cycles after the initial adjustment. If in efficiency-priority mode, and the second average material flow rate is greater than 1.2 times the flow rate setting value, and the linearity coefficient is greater than or equal to 0.8, the pressure setting value is calculated and adjusted according to the relationship between the first average material flow rate and the average bucket wheel pressure. If in efficiency-priority mode, and the second average material flow rate is greater than 1.2 times the flow rate setting value, and the linearity coefficient is less than 0.8, the pressure setting value is adjusted to Pv×Rs / Rate2, where Rs is the flow rate setting value and Rate2 is the second average material flow rate. The pressure setting value is not adjusted again within two bucket wheel rotation cycles after the initial adjustment.

[0016] Furthermore, the adjustment of the pressure setpoint based on the linear coefficient is specifically as follows: if the linear coefficient is greater than or equal to 0.8, the pressure setpoint is calculated and adjusted according to the relationship between the average value of the first material flow rate and the average value of the bucket wheel pressure; if the linear coefficient is less than 0.8, Pv / 0.8, Pv×Rs / Rate1, and Pv×Rs / Rate2 are calculated respectively, the calculation results are sorted, and the pressure setpoint is adjusted to the maximum value among them. The pressure setpoint is not adjusted again within two bucket wheel rotation cycles after the pressure setpoint is adjusted. Attached Figure Description

[0017] Figure 1 A flowchart illustrating the semi-automatic material handling control method for a bulk ore blending and reclaiming machine provided in an embodiment of the present invention, which adjusts the rotation speed according to abnormal operation of the reclaiming machine.

[0018] Figure 2 This is a flowchart illustrating the adjustment of the pressure setpoint in the flow control mode of the semi-automatic material handling control method for the bulk ore mixing and reclaiming machine provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0020] like Figure 1 and Figure 2 As shown, the semi-automatic material handling control method for a bulk ore blending and reclaiming machine proposed in this invention is carried out according to the following steps:

[0021] In the semi-automatic operation mode of the material reclaimer, the travel, rotation, and pitch directions of the reclaimer are still manually controlled by the operator. The corresponding mechanism will stop operating when no directional command is given. The travel, rotation, pitch, and bucket wheel rotation speeds, as well as the travel and pitch distances, are automatically controlled by the PLC according to set parameters. When the material reclaimer is operating on a single layer and the material ratio of each reclaimer is normal, the bucket wheel rotation speed is a fixed rated value. The operator only needs to specify the rotation direction, and the PLC automatically adjusts the material handling capacity by controlling the cantilever rotation speed.

[0022] The system acquires the flow rate setpoint, pressure setpoint, rotation speed, operating mode, rated operating flow rate of the reclaimer, flow rate limit of the reclaimer, bucket wheel pressure limit, bucket wheel rotation cycle, rotation boundary angle, sliding angle, and rated working pressure of the bucket wheel. In this embodiment, based on experience, the pressure setpoint is 1.2 times the flow rate setpoint.

[0023] The operating modes include pressure control mode / flow control mode, low material head priority mode / efficiency priority mode. The operating mode is selected manually according to the usage requirements. The efficiency priority mode, compared to the low material head priority mode, allows for short-term material flow exceeding the set flow rate value. It is generally used when the material characteristics are uniform and the material conveying status of the belt conveyor and hopper is stable.

[0024] The pressure control mode, used in conjunction with a pressure setpoint, allows the PLC to directly maintain the bucket wheel's working pressure at the setpoint via PID instructions. This mode is suitable for conditions where the resistance characteristics of materials, such as stack tops, frozen materials, and materials with high moisture content, vary significantly. The flow control mode, used in conjunction with a flow setpoint, allows the PLC to adjust the bucket wheel's working pressure using PID instructions based on the flow setpoint. This mode is suitable for conditions where the material characteristics are relatively stable.

[0025] The material flow rate and bucket wheel working pressure are monitored and continuously recorded. The operation of the reclaimer is also monitored; if abnormal operation occurs, the rotation speed is adjusted, specifically in the following situations:

[0026] 1. When the material flow rate exceeds the flow limit, or the bucket wheel working pressure exceeds the bucket wheel pressure limit, or the bucket wheel working pressure exceeds 1.4 times the pressure setting value, the reclaimer is determined to have entered an abnormal state, and the cantilever is controlled to stop rotating. The duration and number of triggers of the reclaimer entering the abnormal state are monitored. When the duration of the reclaimer entering the abnormal state is greater than one bucket wheel rotation cycle or the abnormal state is triggered twice consecutively, the bucket wheel is controlled to stop moving, and the semi-automatic control mode is exited. In this embodiment, one bucket wheel rotation cycle is 12 seconds.

[0027] 2. The sliding angle is the angle at which the cantilever of the reclaimer slides from its maximum rotational speed to its inertial stop. The cantilever rotational angle is monitored, and the difference between the cantilever rotational angle and the rotational boundary angle is calculated. When this difference is less than the sliding angle, the cantilever enters the boundary deceleration zone, reducing its rotational speed until the cantilever rotational angle reaches the rotational boundary angle or a signal to stop the current rotational direction is received, at which point the rotational speed is reduced to zero. In this embodiment, when the cantilever rotational speed is below 30% of the maximum rotational speed, the drive system of the rotational mechanism can eliminate equipment inertia and enter a state where it can be stopped at any time. After the reclaimer cantilever reaches its maximum rotational speed under rated load, it needs to slide at least 1.5° to reduce its speed to below 30%. Therefore, the sliding angle is set to 1.5°. When the rotational speed is higher than 30% of the maximum rotational speed, the rotational speed is controlled to decrease to 30% of the maximum rotational speed until the cantilever rotational angle reaches the rotational boundary angle or a signal to stop the current rotational direction is received, at which point the rotational speed is reduced to zero.

[0028] 3. Calculate the oscillation amplitude of the bucket wheel's working pressure. Specifically, obtain the maximum and minimum values ​​of the bucket wheel's working pressure within one working pressure fluctuation cycle. Calculate the difference between the maximum and minimum values; this difference is the oscillation amplitude of the bucket wheel's working pressure. If the oscillation amplitude of the bucket wheel's working pressure continuously exceeds 50% of the rated working pressure within one bucket wheel rotation cycle, then reduce the rotation speed by 50%.

[0029] 4. If the working pressure of the bucket wheel remains greater than 110% of the pressure setting value within one bucket wheel rotation cycle, the rotation speed will be continuously reduced to 90% of the rotation speed at the end of the previous adjustment cycle, with an adjustment period of 1 second, until the working pressure of the bucket wheel is less than or equal to 110% of the pressure setting value. If the working pressure of the bucket wheel remains less than 90% of the pressure setting value within one bucket wheel rotation cycle, the rotation speed will be continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle, with an adjustment period of one bucket wheel rotation cycle, until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value. If the working pressure of the bucket wheel remains below 60% of the pressure setting value within one bucket wheel rotation cycle, in order to prevent the working pressure of the bucket wheel from increasing too quickly, the rotation speed is continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle, with an adjustment cycle of 1 second, until the working pressure of the bucket wheel is greater than or equal to 60% of the pressure setting value. Then, with another bucket wheel rotation cycle as the adjustment cycle, the rotation speed is continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle, until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value.

[0030] When adjusting the rotation speed due to abnormal operation of the reclaimer, to avoid the "shock" phenomenon of a sudden and significant increase or decrease in the PID output value when switching back to normal operation, the software manual mode of the PID control instruction needs to be used. In software manual mode, the output value uses the control variable (CV) set by the PLC logic operation, but the PID instruction will maintain the value of the inverse calculation of the integral accumulation term, and the PID integral accumulation term will match the software manual output value. Conversely, when the PID instruction is in automatic mode, the PID instruction will automatically calculate and output the control variable (CV) based on the set parameters and process variable (SV). When the PID instruction switches from software manual mode to automatic mode, the CV output can be recalculated based on the software manual output value.

[0031] When in pressure control mode, the pressure setpoint remains unchanged. When in flow control mode, the pressure setpoint is adjusted based on the material flow rate, bucket wheel working pressure, flow setpoint, and operating mode, specifically as follows:

[0032] Calculate the average value of the first material intake flow rate and the average value of the bucket wheel pressure within the latest bucket wheel rotation cycle, as well as the average value of the second material intake flow rate within the latest two bucket wheel rotation cycles, based on the material intake flow rate and the bucket wheel working pressure.

[0033] The linear coefficient between the material intake flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle is calculated based on the average value of the first intake flow rate and the average value of the bucket wheel pressure. Specifically, with a sampling period of 1 second, the monitored material intake flow rate and bucket wheel working pressure in the latest bucket wheel rotation cycle are collected and recorded. The linear coefficient between the material intake flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle is calculated using the following formula: , where R 2 P are linear coefficients. i Let Pv be the working pressure of the i-th bucket wheel, Pv be the average bucket wheel pressure, Rate1 be the average first material handling flow rate, and R be the average flow rate. i Let i be the material flow rate for the i-th material intake, where i = 1, 2, ..., n.

[0034] The average value of the first material intake flow rate is compared with the rated operating flow rate. When the average value of the first material intake flow rate is greater than 70% of the rated operating flow rate and the linear coefficient is greater than or equal to 0.8, it is determined that the average value of the first material intake flow rate and the average value of the bucket wheel pressure satisfy a positive proportional relationship. The relationship between the average value of the first material intake flow rate and the average value of the bucket wheel pressure is then calculated according to the linear regression equation, i.e., Rate1 = k × Pv + b. b = Rate1 - k × Pv.

[0035] When the material flow rate exceeds 1.4 times the set flow rate or exceeds 1.2 times the set flow rate within one consecutive bucket wheel rotation cycle, the maximum working pressure of the bucket wheel within the latest rotation cycle is obtained. The pressure set value is then compared with both the average bucket wheel pressure and the maximum working pressure. If the average bucket wheel pressure is less than or equal to 1.3 times the set pressure or the maximum working pressure is less than or equal to 1.5 times the set pressure, the pressure set value is adjusted according to the operating mode, specifically as follows:

[0036] If in the low-material-priority mode, the pressure setting value is adjusted to equal the average bucket wheel pressure / 1.2. The pressure setting value will not be adjusted again within two bucket wheel rotation cycles after the adjustment, and the pressure setting value will not be increased within five bucket wheel rotation cycles after the adjustment.

[0037] If in efficiency-priority mode, and the average second material flow rate is greater than 1.2 times the flow rate setting, and the linearity coefficient is greater than or equal to 0.8, then the pressure setting is calculated and adjusted according to the relationship between the average first material flow rate and the average bucket wheel pressure. If in efficiency-priority mode, and the average second material flow rate is greater than 1.2 times the flow rate setting, and the linearity coefficient is less than 0.8, then the pressure setting is adjusted to Pv×Rs / Rate2, where Rs is the flow rate setting and Rate2 is the average second material flow rate; the pressure setting is not adjusted again within two bucket wheel rotation cycles after the pressure setting is adjusted.

[0038] If the material flow rate is less than 0.8 times the flow rate setting value within one consecutive bucket wheel rotation cycle, or if the first average material flow rate is less than 0.8 times the flow rate setting value, or if the second average material flow rate is less than the flow rate setting value, the pressure setting value is adjusted according to the linearity coefficient. Specifically: if the linearity coefficient is greater than or equal to 0.8, the pressure setting value is calculated and adjusted according to the relationship between the first average material flow rate and the average bucket wheel pressure; if the linearity coefficient is less than 0.8, Pv / 0.8, Pv×Rs / Rate1, and Pv×Rs / Rate2 are calculated respectively, and the calculation results are sorted. The pressure setting value is adjusted to the maximum value among them, and the pressure setting value is not adjusted again within the next two bucket wheel rotation cycles after the adjustment.

[0039] The PID instruction is invoked and its basic setpoint is tuned. The control variable parameter is the rotational speed, and the process variable parameter is the bucket wheel working pressure. Due to the tilt angle of the bucket wheel, the basic setpoint of the PID instruction is tuned separately for both rotation directions. The proportional, integral, and derivative parameters Kp, Ki, and Kd in the tuning instruction are used. The basic setpoint of the PID instruction for both rotation directions is tuned according to the following steps: When the reclaimer operates in the middle area of ​​different types of material stacks, in a single rotation direction, the PID parameter set is tested under the rated load of the reclaimer using the PID parameter tuning method, and the parameter fluctuation range is recorded. The PID parameter tuning method can use conventional methods. Based on the parameter fluctuation range of each parameter set, if a parameter set applicable to more than 80% of the working conditions exists, the parameter set applicable to more than 80% of the working conditions is used as the basic setpoint; otherwise, the parameter sets corresponding to different types of materials are recorded as the basic setpoints for those different types of materials. The rotational speed is adjusted using the PID instruction to make the bucket wheel working pressure reach the pressure setpoint. Before using the semi-automatic material handling mode, the operator selects the basic setting value for the corresponding material based on the current material.

[0040] Therefore, a relationship between the material handling flow rate and the bucket wheel working pressure was established, and both were monitored in real time. To achieve the set flow rate, the pressure setpoint was continuously adjusted. Then, the rotation speed was adjusted using PID instructions to ensure the bucket wheel working pressure reached the set pressure value, thereby achieving the set material handling flow rate. By using PLC control logic in conjunction with PID instructions, a semi-automatic operation mode for the material reclaimer was developed. This enabled precise automatic control of the handling flow rate of bulk ore by the material reclaimer's PLC, significantly reducing the operational difficulty of mixing and handling materials.

[0041] The embodiments of this invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A semi-automatic material handling control method for a bulk ore blending and reclaiming machine, characterized in that, Follow these steps: Acquire flow rate setpoint, pressure setpoint, rotation speed, and operating mode, including pressure control mode and flow rate control mode; The material intake flow rate and bucket wheel working pressure were monitored separately. When in pressure control mode, the pressure setpoint remains unchanged; when in flow control mode, the pressure setpoint is adjusted according to the material intake flow rate, bucket wheel working pressure, flow setpoint, and low material head priority mode / efficiency priority mode. Call the PID instruction and tune the basic tuning value of the PID instruction, where the control variable parameter is the rotation speed and the process variable parameter is the bucket wheel working pressure; The slewing speed is adjusted by PID commands to ensure that the working pressure of the bucket wheel reaches the set pressure value. This also includes monitoring the operation of the reclaimer, and adjusting the rotation speed when the reclaimer malfunctions, specifically: Obtain the flow rate limit, bucket wheel pressure limit, bucket wheel rotation cycle, slewing boundary angle, sliding angle, and rated working pressure of the bucket wheel for the reclaimer; wherein, the sliding angle is the angle at which the cantilever of the reclaimer slides from its maximum slewing speed to its inertial stop. When the material flow rate exceeds the flow limit, or the bucket wheel working pressure exceeds the bucket wheel pressure limit, or the bucket wheel working pressure exceeds 1.4 times the pressure setting value, the material reclaimer is determined to be in an abnormal state, and the cantilever is controlled to stop rotating. The duration and number of triggers of the material reclaimer entering the abnormal state are monitored. When the duration of the material reclaimer entering the abnormal state is greater than one bucket wheel rotation cycle or the abnormal state is triggered twice consecutively, the bucket wheel is controlled to stop moving and the semi-automatic control mode is exited. The cantilever rotation angle is monitored, and the angle difference between the cantilever rotation angle and the rotation boundary angle is calculated. When the angle difference is less than the sliding angle, the rotation speed is reduced until the cantilever rotation angle reaches the rotation boundary angle or a signal to stop the current rotation direction is received, at which point the rotation speed is reduced to zero. Calculate the oscillation amplitude of the bucket wheel's working pressure. If the oscillation amplitude of the bucket wheel's working pressure continues to exceed 50% of the rated working pressure within one bucket wheel rotation cycle, then reduce the rotation speed by 50%. If the working pressure of the bucket wheel is continuously greater than 110% of the pressure setting value or less than 90% of the pressure setting value within one bucket wheel rotation cycle, adjust the rotation speed until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value and less than or equal to 110% of the pressure setting value.

2. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 1, characterized in that, The calculation of the bucket wheel working pressure oscillation amplitude is specifically as follows: Obtain the maximum and minimum values ​​of the bucket wheel working pressure within a single working pressure fluctuation cycle; Calculate the difference between the maximum and minimum values; this difference represents the oscillation amplitude of the bucket wheel's working pressure.

3. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 1, characterized in that, If, within one bucket wheel rotation cycle, the working pressure of the bucket wheel remains greater than 110% of the pressure setting value or less than 90% of the pressure setting value, the rotation speed shall be adjusted until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value and less than or equal to 110% of the pressure setting value. Specifically: If the working pressure of the bucket wheel continues to be greater than 110% of the pressure setting value within one bucket wheel rotation cycle, then the rotation speed will be continuously reduced to 90% of the rotation speed at the end of the previous adjustment cycle, with an adjustment cycle of 1 second, until the working pressure of the bucket wheel is less than or equal to 110% of the pressure setting value; If the working pressure of the bucket wheel is consistently less than 90% of the pressure set value within one bucket wheel rotation cycle, then one bucket wheel rotation cycle shall be used as the adjustment cycle, and the rotation speed shall be continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure set value. If the working pressure of the bucket wheel is consistently less than 60% of the pressure setting value within one bucket wheel rotation cycle, the rotation speed is continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle, with a 1-second adjustment cycle, until the working pressure of the bucket wheel is greater than or equal to 60% of the pressure setting value. Then, with another bucket wheel rotation cycle as the adjustment cycle, the rotation speed is continuously increased to 120% of the rotation speed at the end of the previous adjustment cycle, until the working pressure of the bucket wheel is greater than or equal to 90% of the pressure setting value.

4. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 1, characterized in that, The basic tuning value for the PID tuning instruction is as follows: The basic tuning values ​​of the PID commands for both turning directions are tuned separately, and the tuning of the basic tuning values ​​of the PID commands for both turning directions is performed according to the following steps: When the reclaimer operates in the middle area of ​​the stack of different types of materials, in a single rotation direction, the PID parameter set is tested under the rated load of the reclaimer using the PID parameter tuning method, and the parameter fluctuation range is recorded. Based on the parameter fluctuation range of each parameter set, if there is a parameter set applicable to more than 80% of the working conditions, then the parameter set applicable to more than 80% of the working conditions is used as the basic tuning value; otherwise, the parameter sets corresponding to different types of materials are recorded separately as the basic tuning values ​​for different types of materials.

5. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 1, characterized in that: Calculate the average value of the first material intake flow rate and the average value of the bucket wheel pressure within the latest bucket wheel rotation cycle, as well as the average value of the second material intake flow rate within the latest two bucket wheel rotation cycles, based on the material intake flow rate and the bucket wheel working pressure. The linearity coefficient between the material intake flow rate and the working pressure of the bucket wheel in the latest bucket wheel rotation cycle is calculated based on the average value of the first material intake flow rate and the average value of the bucket wheel pressure. When the material intake flow rate is greater than 1.4 times the flow rate setting value or the material intake flow rate is greater than 1.2 times the flow rate setting value within one consecutive bucket wheel rotation cycle, the maximum working pressure of the bucket wheel within the latest bucket wheel rotation cycle is obtained, and the pressure setting value is compared with the average bucket wheel pressure and the maximum working pressure of the bucket wheel respectively; if the average bucket wheel pressure is less than or equal to 1.3 times the pressure setting value or the maximum working pressure of the bucket wheel is less than or equal to 1.5 times the pressure setting value, the pressure setting value is adjusted according to the low material head priority mode / efficiency priority mode; If the material flow rate is less than 0.8 times the flow rate setting value within one consecutive bucket wheel rotation cycle, or if the first average material flow rate is less than 0.8 times the flow rate setting value, or if the second average material flow rate is less than the flow rate setting value, then the pressure setting value will be adjusted according to the linearity coefficient.

6. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 5, characterized in that, The linear coefficient between the material intake flow rate and the bucket wheel working pressure in the latest bucket wheel rotation cycle is calculated based on the average value of the first material intake flow rate and the average value of the bucket wheel pressure, specifically as follows: With a data acquisition cycle of 1 second, the system collects and records the material handling flow rate and bucket wheel working pressure monitored during the latest bucket wheel rotation cycle. The linearity coefficient between the material handling capacity and the working pressure of the bucket wheel in the latest bucket wheel rotation cycle is calculated using the following formula: , where R 2 P are linear coefficients. i Let Pv be the working pressure of the i-th bucket wheel, Pv be the average bucket wheel pressure, Rate1 be the average first material handling flow rate, and R be the average flow rate. i Let i be the material flow rate for the i-th material intake, where i = 1, 2, ..., n.

7. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 6, characterized in that, After calculating the linearity coefficient between the feed rate and the working pressure of the bucket wheel in the latest bucket wheel rotation cycle based on the average feed rate and the average bucket wheel pressure of the first feed rate, the following is also included: Obtain the rated operating flow rate of the material reclaimer; The average value of the first material intake flow rate is compared with the rated operating flow rate. When the average value of the first material intake flow rate is greater than 70% of the rated operating flow rate and the linear coefficient is greater than or equal to 0.8, it is determined that the average value of the first material intake flow rate and the average value of the bucket wheel pressure satisfy a positive proportional relationship. The relationship between the average value of the first material intake flow rate and the average value of the bucket wheel pressure is calculated according to the linear regression equation, i.e., Rate1 = k × Pv + b; where, ,b=Rate1-k×Pv。 8. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 7, characterized in that, The adjustment of the pressure setpoint according to the low-material-head-priority mode / efficiency-priority mode is specifically as follows: If in the low-material-head-priority mode, the pressure setting value is adjusted to equal the average bucket wheel pressure / 1.

2. The pressure setting value will not be adjusted again within two bucket wheel rotation cycles after the adjustment, and the pressure setting value will not be increased within five bucket wheel rotation cycles after the adjustment. If the system is in efficiency-first mode, and the average second material flow rate is greater than 1.2 times the flow rate setpoint, and the linearity coefficient is greater than or equal to 0.8, then the pressure setpoint is calculated and adjusted according to the relationship between the average first material flow rate and the average bucket wheel pressure. If the system is in efficiency-first mode, and the average second material flow rate is greater than 1.2 times the flow rate setting value, and the linearity coefficient is less than 0.8, then the pressure setting value is adjusted to Pv×Rs / Rate2, where Rs is the flow rate setting value and Rate2 is the average second material flow rate. The pressure setting value will not be adjusted again within two bucket wheel rotation cycles after the pressure setting value is adjusted.

9. The semi-automatic material handling control method for the bulk ore blending and reclaiming machine according to claim 8, characterized in that, The adjustment of the pressure setpoint based on the linear coefficient is specifically as follows: If the linearity coefficient is greater than or equal to 0.8, the pressure setpoint is calculated and adjusted according to the relationship between the average value of the first material intake flow rate and the average value of the bucket wheel pressure. If the linear coefficient is less than 0.8, calculate Pv / 0.8, Pv×Rs / Rate1, and Pv×Rs / Rate2 respectively, sort the calculation results, adjust the pressure setpoint to the maximum value among them, and do not adjust the pressure setpoint again within two bucket wheel rotation cycles after adjusting the pressure setpoint.

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