A PID-based kitchen garbage dual-shaft crushing system and control method

Abstract

The application discloses a kind of PID-based kitchen garbage double-shaft crushing system and control method, wherein system includes storage bin, double-shaft crusher, current acquisition module, PID control module, storage bin valve, stepper motor, screw rod;Storage bin is set above double-shaft crusher, storage bin valve is slidably set at the bottom of storage bin, one end of screw rod is connected with the output shaft of stepper motor, and the side of storage bin valve is connected with the slider set on screw rod;Current acquisition module and stepper motor are electrically connected with PID control module;Current acquisition module is used to collect the current of double-shaft crusher;PID control module is used to control the pulse width input value of stepper motor according to the current of double-shaft crusher received to control the opening of storage bin valve.The control precision is high, the double-shaft crusher can run in the best operating state, the highest throughput can be realized, the wear and overload of double-shaft crusher can be reduced, and the production efficiency, safety and stability can be improved.

Description

Technical Field

[0001] This invention relates to the field of waste treatment technology, and in particular to a PID-based dual-shaft crushing system and control method for kitchen waste. Background Technology

[0002] In the production of food waste crushing, the crusher is the most important piece of equipment in the entire process, but it is also one of the most unstable pieces of equipment. Currently, the control of crushing equipment in food waste production is mainly based on manual operation. Due to the odor it produces, this can affect the health of production workers to some extent. Furthermore, the complex composition of food waste often leads to entanglement, causing overload, frequent crusher blockages and shutdowns, high failure rates, and reduced crusher lifespan. Therefore, an intelligent food waste crushing system is particularly important for controlling the amount of food waste processed and addressing crushing equipment problems.

[0003] Against this backdrop, the inventors proposed a new control method for crushing equipment to solve the aforementioned problems. The PID (proportional, integral, differential) controller, as the earliest practical controller, has a history of nearly a century and remains the most widely used industrial controller. The PID controller is simple and easy to understand, requiring no precise system model or other prerequisites for its use, thus becoming the most widely applied controller. Using the PID algorithm of an intelligent control system to control the feeding, and employing a closed-loop control method to ensure the crushing motor operates at a constant load rate, achieves long-term stable operation of the kitchen waste crushing equipment.

[0004] Current valve control methods mainly rely on electric valve control. The control signal of the electric valve is a current value of 4-20mA, which is sent to the controller through A / D conversion. However, this control method has low accuracy and cannot accurately control the feed rate of the twin-shaft crusher. Summary of the Invention

[0005] This invention provides a PID-based dual-shaft crushing system and control method for kitchen waste, which solves the problem that existing control schemes cannot accurately control the feed rate of the dual-shaft crusher and cannot keep the crusher running in a stable state for a long time.

[0006] Firstly, a PID-based dual-shaft crushing system for kitchen waste is provided, including a storage bin, a dual-shaft crusher, a current acquisition module, a PID control module, a storage bin valve, a stepper motor, and a lead screw;

[0007] The storage bin is located above the twin-shaft crusher. The storage bin valve is slidably located at the bottom of the storage bin. One end of the lead screw is connected to the output shaft of the stepper motor, and one side of the storage bin valve is connected to a slider located on the lead screw.

[0008] The current acquisition module and the stepper motor are both electrically connected to the PID control module;

[0009] The current acquisition module is used to acquire the current of the twin-shaft crusher; the PID control module is used to control the pulse width input value of the stepper motor according to the received current of the twin-shaft crusher to control the opening of the storage silo valve.

[0010] Furthermore, it also includes an encoder mounted on the output shaft of the stepper motor, used to detect the position information of the storage silo valve and send it to the PID control module.

[0011] Furthermore, the current acquisition module is a current transformer.

[0012] Furthermore, the two motors of the twin-shaft crusher are controlled by a single frequency converter.

[0013] Secondly, a control method for a PID-based dual-shaft crushing system for kitchen waste, as described above, is provided, including:

[0014] The real-time average current of the twin-shaft crusher is used as the measured value, the pulse width input value of the stepper motor is used as the control variable, and the ideal current value of the twin-shaft crusher is used as the set value.

[0015] Set a sampling control cycle. In each sampling control cycle, sample the real-time current of the twin-shaft crusher and calculate the average real-time current. Calculate the pulse width input value of the stepper motor based on the deviation between the average real-time current of the twin-shaft crusher and the ideal current value of the twin-shaft crusher. Control the stepper motor based on the pulse width input value of the stepper motor to adjust the opening of the storage hopper valve.

[0016] Furthermore, the pulse width input value of the stepper motor is calculated using the following formula:

[0017] ΔP n =K p (P n -P n-1 )+K i P n +K d (P n -2P n-1 +P n-2 )

[0018] In the formula, ΔP nP represents the pulse width input value corresponding to the nth sampling control cycle; n P represents the deviation value corresponding to the nth sampling control cycle; n-1 P represents the deviation value corresponding to the (n-1)th sampling control cycle; n-2 K represents the deviation value corresponding to the (n-2)th sampling control cycle; p Represents the proportionality coefficient; K i K represents the integral coefficient; d Represents the differential coefficient.

[0019] Furthermore, it also includes the initialization process:

[0020] First, give the stepper motor an initial pulse width input value P0. The stepper motor controls the opening of the storage bin valve, thereby controlling the feed rate of the twin-shaft crusher.

[0021] At preset operating time intervals, the real-time current of the main motor of the twin-shaft crusher is collected and the average real-time current I is calculated. The average real-time current I is then compared with the ideal current value I of the twin-shaft crusher. max When the real-time average current I of the twin-shaft crusher is less than the ideal current value I of the twin-shaft crusher max At this time, the PID control module inputs a positive pulse width input value to the stepper motor, causing the opening of the storage hopper valve to increase; when the real-time average current I of the twin-shaft crusher is greater than the ideal current value I of the twin-shaft crusher... max At this time, the PID control module inputs a negative pulse width input value to the stepper motor, causing the opening of the storage silo valve to decrease;

[0022] Based on the real-time average current I and the ideal current value I of the twin-shaft crusher max Adjust the values ​​of the proportional coefficient, integral coefficient, and derivative coefficient in sequence according to the changes in the deviation value, and record the final proportional coefficient, integral coefficient, and derivative coefficient.

[0023] This invention proposes a PID-based dual-shaft crushing system and control method for kitchen waste. By combining a stepper motor, a lead screw, and a storage hopper valve, the control of the storage hopper valve opening is transformed into linear motion control, which facilitates the control of the feed rate of the dual-shaft crusher and improves control accuracy. Simultaneously, by using PID-based control of the stepper motor's pulse width input value, the dual-shaft crusher can operate in its optimal state, achieving maximum throughput and effectively increasing the output of kitchen waste. This maximizes the ideal processing state, realizes optimal feeding configuration, improves the crushing effect of kitchen waste, and reduces wear and overload of the dual-shaft crusher, thereby improving its production efficiency, safety, and stability. Attached Figure Description

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

[0025] Figure 1 This is a schematic diagram of the structure of the PID-based dual-shaft crushing system for kitchen waste provided in an embodiment of the present invention;

[0026] Figure 2 This is a PID control flowchart provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "top," "bottom," "vertical," and "horizontal," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. When an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present.

[0029] like Figure 1 As shown, this embodiment of the invention provides a PID-based dual-shaft crushing system for kitchen waste, including a storage bin 3, a dual-shaft crusher 9, a current acquisition module 2, a PID control module 8, a storage bin valve 4, a stepper motor 6, and a lead screw 5;

[0030] The storage bin 3 is located above the twin-shaft crusher 9. The storage bin valve 4 is slidably located at the bottom of the storage bin 3. One end of the lead screw 5 is connected to the output shaft of the stepper motor 6, and one side of the storage bin valve 4 is connected to the slider located on the lead screw 5.

[0031] The current acquisition module 2 and the stepper motor 6 are both electrically connected to the PID control module 8;

[0032] The current acquisition module 2 is used to acquire the current of the twin-shaft crusher 9; the PID control module 8 is used to control the pulse width input value of the stepper motor 6 according to the received current of the twin-shaft crusher to control the opening of the storage silo valve 4.

[0033] During operation, the feeder first transports kitchen waste to the storage hopper 3. Then, the PID control module 8 controls the stepper motor 6 to rotate forward, driving the slider on the lead screw 5 to move linearly, which in turn drives the storage hopper valve 4 to move laterally, opening the valve to its initial position. Simultaneously, the PID control module 8 controls the twin-shaft crusher 9 to start working. During operation, the current acquisition module 2 collects the current of the twin-shaft crusher 9 in real time at a preset cycle and compares it with the set ideal current of the twin-shaft crusher. Based on the deviation, it calculates the pulse width input value of the stepper motor 6 to control the opening of the storage hopper valve 4. By combining the stepper motor 6, the lead screw 5, and the storage hopper valve 4, the opening control of the storage hopper valve 4 is transformed into linear motion control, which facilitates the control of the feed rate of the twin-shaft crusher 9 and improves control accuracy. At the same time, by adopting the pulse width input value based on PID control of the stepper motor 6, the twin-shaft crusher 9 can operate in the optimal operating state, control the twin-shaft crusher 9 to achieve the highest throughput, effectively increase the output of kitchen waste processing, achieve the maximum ideal processing state, realize the optimal feeding configuration, improve the crushing effect of kitchen waste, and at the same time reduce the wear and overload of the twin-shaft crusher, thereby improving the production efficiency, safety, and stability of the twin-shaft crusher 9.

[0034] In some preferred embodiments, an encoder 7 is also included on the output shaft of the stepper motor 6, used to detect the position information of the storage hopper valve 4 and send it to the PID control module 8. The PID control module 8 calculates the opening position of the storage hopper valve 4 that needs to be controlled based on the pulse width input value, and at the same time collects the actual opening position information of the storage hopper valve 4 through the encoder 7 and compares it to determine whether the actual opening of the storage hopper valve 4 is the opening position that needs to be controlled, so as to determine whether there is a fault.

[0035] The two motors 1 of the twin-shaft crusher 9 are of the same model and are controlled by the same frequency converter 10. They start, stop, and rotate simultaneously, with the two motors 1 rotating in opposite directions. When an overload is detected, i.e., the average current of the twin-shaft crusher 9 exceeds the overload threshold, the PID control module 8 controls the stepper motor 6 to close the storage hopper valve 4, stopping the feeding, and the frequency converter 10 controls the twin-shaft crusher 9 to stop the motors. Additionally, a motor reversal button can be provided; pressing the reversal button relieves the overload.

[0036] In this embodiment, the current acquisition module 2 is preferably a current transformer, which is connected to the motor 1 of the twin-shaft crusher 9 and is used to monitor the current information of the motor 1 of the twin-shaft crusher 9. The PID control module 8 can be a Siemens PLCS7-200smart.

[0037] This invention also provides a control method for a PID-based dual-shaft crushing system for kitchen waste as described above, comprising:

[0038] The real-time average current of the twin-shaft crusher is used as the measured value, the pulse width input value of the stepper motor is used as the control variable, and the ideal current value of the twin-shaft crusher is used as the set value.

[0039] Set a sampling control cycle. In each sampling control cycle, sample the real-time current of the twin-shaft crusher and calculate the average real-time current. Calculate the pulse width input value of the stepper motor based on the deviation between the average real-time current of the twin-shaft crusher and the ideal current value of the twin-shaft crusher. Control the stepper motor based on the pulse width input value of the stepper motor to adjust the opening of the storage hopper valve.

[0040] The pulse width input value of the stepper motor is calculated using the following formula:

[0041] ΔP n =K p (P n -P n-1 )+K i P n +K d (P n -2P n-1 +P n-2 )

[0042] In the formula, ΔP n P represents the pulse width input value corresponding to the nth sampling control cycle; n P represents the deviation value corresponding to the nth sampling control cycle; n-1 P represents the deviation value corresponding to the (n-1)th sampling control cycle; n-2 K represents the deviation value corresponding to the (n-2)th sampling control cycle; p Represents the proportionality coefficient; K i K represents the integral coefficient; d Represents the differential coefficient.

[0043] Specifically, the working process of the PID control module includes: obtaining the deviation value from the set value and the measured value of the current of the dual-shaft crusher. This deviation value is used by the PID controller to calculate the positive and negative pulse width values ​​for driving the stepper motor. When the deviation signal is positive, QLMNUP in the PID control module is 1, which drives the stepper motor to rotate forward, increasing the valve opening; when QLMNUP becomes 0, the stepper motor stops, and the valve remains in its original position. The degree of valve position increase is determined by the width of the QLMNUP pulse; when the deviation signal is negative, this signal drives the stepper motor to rotate in reverse, decreasing the valve opening. The degree of valve position decrease is determined by the width of the QLMNDN pulse signal, which directly controls the increase or decrease of the valve opening.

[0044] Before formal operation and control, an initialization process is also included to determine the proportional coefficient, integral coefficient, derivative coefficient, and the initial opening degree of the storage silo valve. The initialization process is as follows:

[0045] First, give the stepper motor an initial pulse width input value P0. The stepper motor controls the opening of the storage bin valve, thereby controlling the feed rate of the twin-shaft crusher.

[0046] At preset time intervals (e.g., 10s or 20s), the real-time current of the main motor of the twin-shaft crusher is collected and the average real-time current I is calculated. The average real-time current I is then compared with the ideal current value I of the twin-shaft crusher. max When the real-time average current I of the twin-shaft crusher is less than the ideal current value I of the twin-shaft crusher max At this time, the PID control module inputs a positive pulse width input value to the stepper motor, causing the opening of the storage hopper valve to increase; when the real-time average current I of the twin-shaft crusher is greater than the ideal current value I of the twin-shaft crusher... max At this time, the PID control module inputs a negative pulse width input value to the stepper motor, causing the opening of the storage silo valve to decrease;

[0047] Based on the real-time average current I and the ideal current value I of the twin-shaft crusher max The values ​​of the proportional coefficient, integral coefficient, and derivative coefficient are adjusted sequentially according to the change in deviation value. The final proportional coefficient, integral coefficient, derivative coefficient, and valve opening are recorded, and this valve opening is used as the initial opening of the storage silo valve.

[0048] After the initialization process is completed once, the operating parameters (including proportional coefficient, integral coefficient, derivative coefficient and initial opening degree of storage silo valve) can be stored in the system. The next time the equipment is started, it can choose to run according to the stored parameters or re-execute the initialization.

[0049] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A dual-shaft crushing system for kitchen waste based on PID control, characterized in that, Includes storage silos, twin-shaft crushers, current acquisition modules, PID control modules, storage silo valves, stepper motors, and lead screws; The storage bin is located above the twin-shaft crusher. The storage bin valve is slidably located at the bottom of the storage bin. One end of the lead screw is connected to the output shaft of the stepper motor, and one side of the storage bin valve is connected to a slider located on the lead screw. The current acquisition module and the stepper motor are both electrically connected to the PID control module; The current acquisition module is used to acquire the current of the twin-shaft crusher; the PID control module is used to control the pulse width input value of the stepper motor according to the received current of the twin-shaft crusher to control the opening of the storage silo valve. It also includes an encoder mounted on the output shaft of the stepper motor, used to detect the position information of the storage bin valve and send it to the PID control module; The PID control module calculates the required opening position of the storage silo valve based on the pulse width input value. At the same time, it collects the actual opening position information of the storage silo valve through the encoder and compares it to determine whether the actual opening position of the storage silo valve is the required opening position, so as to determine whether there is a fault.

2. The PID-based dual-shaft crushing system for kitchen waste according to claim 1, characterized in that, The current acquisition module is a current transformer.

3. The PID-based dual-shaft crushing system for kitchen waste according to claim 1, characterized in that, The two motors of the twin-shaft crusher are controlled by a frequency converter.

4. A control method for a PID-based dual-shaft crushing system for kitchen waste as described in any one of claims 1 to 3, characterized in that, include: The real-time average current of the twin-shaft crusher is used as the measured value, the pulse width input value of the stepper motor is used as the control variable, and the ideal current value of the twin-shaft crusher is used as the set value. Set a sampling control cycle. In each sampling control cycle, sample the real-time current of the twin-shaft crusher and calculate the average real-time current. Calculate the pulse width input value of the stepper motor based on the deviation between the average real-time current of the twin-shaft crusher and the ideal current value of the twin-shaft crusher. Control the stepper motor based on the pulse width input value of the stepper motor to adjust the opening of the storage hopper valve.

5. The control method for the PID-based dual-shaft crushing system for kitchen waste according to claim 4, characterized in that, The pulse width input value of the stepper motor is calculated using the following formula: ； In the formula, The input value represents the pulse width of the output corresponding to the nth sampling control cycle; This represents the deviation value corresponding to the nth sampling control cycle; This represents the deviation value corresponding to the (n-1)th sampling control cycle; This represents the deviation value corresponding to the (n-2)th sampling control cycle; Represents the proportionality coefficient; Represents the integral coefficient; Represents the differential coefficient.

6. The control method for the PID-based dual-shaft crushing system for kitchen waste according to claim 5, characterized in that, It also includes the initialization process: First, give the stepper motor an initial pulse width input value. The stepper motor controls the opening of the storage bin valve, thereby controlling the feed rate of the twin-shaft crusher; At preset operating time intervals, the real-time current of the main motor of the twin-shaft crusher is collected and the average real-time current I is calculated. The average real-time current I is then compared with the ideal current value I of the twin-shaft crusher. max When the real-time average current I of the twin-shaft crusher is less than the ideal current value I of the twin-shaft crusher max At this time, the PID control module inputs a positive pulse width input value to the stepper motor, causing the opening of the storage hopper valve to increase; when the real-time average current I of the twin-shaft crusher is greater than the ideal current value I of the twin-shaft crusher... max At this time, the PID control module inputs a negative pulse width input value to the stepper motor, causing the opening of the storage silo valve to decrease; Based on the real-time average current I and the ideal current value I of the twin-shaft crusher max Adjust the values ​​of the proportional coefficient, integral coefficient, and derivative coefficient in sequence according to the changes in the deviation value, and record the final proportional coefficient, integral coefficient, and derivative coefficient.

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