A fuzzy adaptive control method for a pestle mill

Abstract

This invention discloses a fuzzy adaptive control method for a pestle mill, comprising the following steps: starting the pestle mill, adjusting the Z-axis height of the pestle rod within the pestle mill cavity, and acquiring the discrete mechanical signal M of the powder being milled. hi The extreme values ​​are obtained; the average value of the mechanical signal for each Z-axis height segment is calculated. Within the extreme value range of the mechanical signal, the Z-axis height is changed to obtain the discrete mechanical signal from M. hi The change occurs at the corresponding time; the variance of the discrete mechanical signal for each Z-axis height segment is calculated; the autocorrelation coefficient is obtained; and the M... hi Compensation is performed to obtain the mechanical signal of each Z-axis height segment changing from M′(z) to the corresponding time; the aforementioned steps are repeated until the mill reaches the shutdown standard and automatically stops. This invention can perform both dry and wet grinding, and there is no need to detect the particle size of the powder raw material before grinding. There is no need for manual grinding, and it can achieve uninterrupted adaptive shutdown, with a high level of intelligence and grinding efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of pestle mills, and specifically relates to a fuzzy adaptive control method for pestle mills. Background Technology

[0002] A pestle mill is a small to medium-sized electric mill used in scientific research. Especially in fields such as ceramics, glass, building materials, pharmaceuticals, spectral analysis, geology and mining, and nuclear industry research, where the incoming materials are diverse and varied, pestle mills are often required for fine grinding and mixing of powders. However, current pestle mills in scientific research rely on manual operation and have a low level of automation. When fine grinding powders from multiple sources, the required grinding time is long, necessitating judgment of grinding time based on experimental results. In production applications, occasionally the grinding effect fails to meet production standards, necessitating re-grinding, making it difficult to determine the optimal effect. Summary of the Invention

[0003] To address the technical problems existing in the prior art, the present invention aims to provide a fuzzy adaptive control method for a pestle mill.

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

[0005] A fuzzy adaptive control method for a pestle mill includes the following steps:

[0006] Step 1: Start the pestle mill and adjust the Z-axis height h of the pestle rod within the pestle mill chamber. i The milled powder in the milling chamber was collected within a specific time period t. a Mechanical discrete signal M hi to obtain the extreme value ;

[0007] Step 2: Calculate the average mechanical signal value for each Z-axis height segment. ;

[0008] Step 3: Within the extreme value range of the mechanical signal in Step 1, change the Z-axis height h. i The discrete mechanical signals of each Z-axis height segment are collected from M. hi Change to The corresponding time t ;

[0009] Step 4: Calculate the discrete mechanical signal M for each Z-axis height segment. hi The corresponding variance

[0010] Step 5: Divide the unit time T into N segments, namely t1, t2, t3, t4, t5, ..., tt N Collect discrete mechanical signal values ​​for each time period. And find its relationship with M. hi The autocorrelation coefficient;

[0011] Step six, process the M obtained in step one. hi conduct Compensation, within the extreme value range of the compensated signal, involves changing the Z-axis height to obtain a new mechanical signal for each Z-axis height segment. Change to The corresponding time t new (z), where, ;

[0012] Step 7, based on the state function G Repeat steps one through six. When the shutdown criteria are met, the pestle mill will automatically stop.

[0013] Furthermore, the pestle mill includes a pestle grinding chamber, a pestle grinding rod, a Z-axis lead screw, a motor, and a mechanical signal sensor. The pestle grinding rod is connected to the Z-axis lead screw, which is connected to the motor. The height of the pestle grinding rod in the pestle grinding chamber can be adjusted by the motor along the Z-axis direction, driven by the Z-axis lead screw. The mechanical signal sensor is located below the pestle grinding chamber and collects the discrete mechanical signals of the powder being ground.

[0014] Furthermore, the sampling frequency of the mechanical signal sensor is 30-100MHz.

[0015] Furthermore, in step two, the average value of the mechanical signal... The calculation formula is:

[0016]

[0017] Among them, M i ⊂M hi .

[0018] Furthermore, in step four, variance The calculation formula is:

[0019] .

[0020] Furthermore, in step five, the formula for calculating the autocorrelation coefficient is:

[0021] R t i ,t i+1 *M hi )=

[0022] Among them, t i t i+1 Each corresponds to a different time period.

[0023] Furthermore, in step six, the M obtained in step one... hi conduct The formula for compensation is:

[0024] y(z)=M hi + .

[0025] Furthermore, in step seven, the state function is expressed as:

[0026] G = y .

[0027] Furthermore, in step seven, the shutdown criteria are as follows:

[0028] if If so, continue with steps one through seven until the shutdown criteria are met;

[0029] when At that time, the pestle mill equipment was shut down;

[0030] Where, m= ;

[0031] The Fourier transform of the m-function is used as a global function to prevent device malfunctions from entering an infinite loop.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] This invention discloses a fuzzy adaptive control method for a pestle mill, which can perform both dry and wet grinding. Before grinding, there is no need to detect the particle size of the powder raw material or to manually grind it. When the shutdown standard is reached, the pestle mill automatically stops, realizing uninterrupted adaptive shutdown. It has a high level of intelligence and grinding efficiency. Detailed Implementation

[0034] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0035] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0036] This invention discloses a fuzzy adaptive control method for a pestle mill, which is achieved by adjusting the height of the pestle rod in the pestle mill cavity. The pestle mill includes a pestle mill cavity, a pestle rod, a Z-axis lead screw, a motor, and a mechanical signal sensor. The pestle rod is connected to the Z-axis lead screw, which is connected to the motor. The pestle rod can automatically adjust its height in the pestle mill cavity along the Z-axis direction driven by the motor. The mechanical signal sensor is set below the pestle mill cavity and collects the discrete mechanical signals of the pestle-milled powder in the pestle mill cavity.

[0037] The fuzzy adaptive control method for a pestle mill disclosed in this invention mainly includes the following steps:

[0038] Step 1: After the pestle mill is started, the pestle rod, driven by the motor along the Z-axis direction, automatically adjusts its height within the pestle chamber, changing the Z-axis height h. i The mechanical signal sensor collects data on the powder from the pestle mill over a specific time period (t). a The mechanical discrete signal M) hi to obtain the extreme value The sampling frequency is set to 30-100MHz;

[0039] Step 2: Calculate the average mechanical signal value for each Z-axis height segment. , of which M i ⊂M hi ;

[0040] Step 3: Within the extreme range of the mechanical signal in Step 1, change the Z-axis height and acquire the discrete mechanical signal for each Z-axis height segment from M. hi Change to The corresponding time t ;

[0041] Step 4: Calculate the discrete mechanical signal M for each Z-axis height segment. hi The corresponding variance ;

[0042] Step 5: Divide the unit time T into N segments, namely t1, t2, t3, t4, t5, ..., tt N Collect discrete mechanical signal values ​​for each time period. Calculate them separately With M hi The autocorrelation coefficient is calculated using the following formula:

[0043] R t i ,t i+1 *M hi )=

[0044] Among them, t i t i+1 Each corresponds to a different time period;

[0045] Step six, process the M obtained in step one. hi conduct Compensation, i.e., y(z)=M hi + Within the compensated signal extreme range, the Z-axis height is varied to obtain a new mechanical signal for each Z-axis height segment. Change to The corresponding time t new (z), where ;

[0046] Step 7, based on the state function G = y Repeat steps one through six. When the shutdown criteria are met, the pestle mill will automatically stop. The shutdown criteria are as follows:

[0047] As the mass of large particles decreases during the fine grinding process, the number of small particles increases, and the grinding time to reach the desired particle size becomes shorter and shorter.

[0048] if If so, continue with steps one through seven until the shutdown criteria are met;

[0049] when At that time, the pestle mill equipment automatically stopped;

[0050] Where, m= The Fourier transform of the m-function is used as a global function to prevent device failures from entering an infinite loop.

[0051] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0052] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A fuzzy adaptive control method for a pestle mill, characterized in that, including the following steps: Step 1: Start the pestle mill and adjust the Z-axis height h of the pestle rod within the pestle mill chamber. i The milled powder in the milling chamber was collected within a specific time period t. a Mechanical discrete signal M hi to obtain the extreme value ; Step 2: Calculate the average mechanical signal value for each Z-axis height segment. ; Step 3: Within the extreme value range of the mechanical signal in Step 1, change the Z-axis height h. i The discrete mechanical signals of each Z-axis height segment are collected from M. hi Change to The corresponding time t ; Step 4: Calculate the discrete mechanical signal M for each Z-axis height segment. hi The corresponding variance Step 5: Divide the unit time T into N segments, namely t1, t2, t3, t4, t5, ..., tt N Collect discrete mechanical signal values ​​for each time period. And find its relationship with M. hi The autocorrelation coefficient; Step six, process the M obtained in step one. hi conduct Compensation, within the extreme value range of the compensated signal, involves changing the Z-axis height to obtain a new mechanical signal for each Z-axis height segment. Change to The corresponding time t new (z), where, ; Step 7, based on the state function G Repeat steps one through six until the shutdown criteria are met. The pestle mill will then automatically shut down. In Step 6, for M obtained in Step 1 hi perform The compensation formula is: y(z)=M hi + ; In step seven, the state function is expressed as: G = y ; In step seven, the shutdown criterion is: If , then continue with Steps 1 to 7 until the stop criterion is met; When the pestle mill equipment stops; where m = ; The Fourier transform of the m function is used as the global function to prevent the equipment failure from entering an infinite loop.

2. The fuzzy adaptive control method of a pestle mill according to claim 1, characterized in that, The pestle mill includes a pestle grinding chamber, a pestle grinding rod, a Z-axis screw rod, a motor, and a mechanical signal sensor. The pestle grinding rod is connected to the Z-axis screw rod, the Z-axis screw rod is connected to the motor, and the pestle grinding rod can be driven by the motor along the Z-axis direction to adjust its height in the pestle grinding chamber. The mechanical signal sensor is arranged below the pestle grinding chamber to collect the mechanical discrete signals of the pestle grinding powder through the mechanical signal sensor.

3. The fuzzy adaptive control method of a pestle mill according to claim 2, characterized in that, The sampling frequency of the mechanical signal sensor is 30 - 100 MHz.

4. The fuzzy adaptive control method of a pestle mill according to claim 1, characterized in that, In step two, the average value of the mechanical signal is calculated by the following formula: Among them, M i ⊂M hi .

5. The fuzzy adaptive control method of a pestle mill according to claim 1, characterized in that, In step 4, the variance is calculated by the following formula: 。 6. The fuzzy adaptive control method of a pestle mill according to claim 1, characterized in that, In step five, the calculation formula of the autocorrelation coefficient is: R t i ,t i+1 *M hi )= Among them, t i t i+1 Each corresponds to a different time period.

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