Multi-signal fusion intelligent anti-jamming and constant current control method and system for screw oil press

Abstract

This invention discloses a multi-signal fusion screw oil press anti-jamming and constant current control method and system, belonging to the field of agricultural machinery automation. Addressing the problems of low control accuracy, high fault misjudgment, and the need for manual intervention in existing technologies, the method includes: acquiring and preprocessing motor current, torque, and speed signals; comparing the actual current with the target value through adaptive PID control to adjust the speed and achieve constant current (constant pressure) control; fusion of four parameters (current exceeding threshold + rate of change exceeding threshold + torque exceeding threshold + speed below threshold) to determine jamming; in case of jamming, controlling the motor to reverse material retraction, pausing, and then smoothly restarting. The system includes signal detection, core control, execution drive, and human-machine interaction modules. This invention increases oil yield by 3%-8%, reduces the fault judgment rate to below 5%, reduces downtime to the second level, extends equipment life, and saves energy, and is applicable to various types of screw oil presses.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery automation control technology, specifically to intelligent control technology for screw oil presses, and particularly to a control method and supporting system for screw oil presses based on multi-signal fusion to achieve constant pressure pressing, intelligent anti-jamming and automatic recovery. Background Technology

[0002] The screw oil press is a core piece of equipment in the oil processing industry. Its working principle involves the rotation of the screw pushing the material through the pressing chamber, using mechanical pressure to separate the oil from the material. However, existing screw oil press control technology still has significant shortcomings, making it difficult to meet the demands of modern production for efficiency, quality, and automation. Specific problems are as follows: Traditional control methods have low automation: Traditional screw oil presses rely on operators to manually adjust the screw gap and feed rate based on experience to control the pressing pressure inside the pressing chamber. This method is not only labor-intensive, but also susceptible to fluctuations in pressing pressure due to differences in operator experience, resulting in unstable oil yield (fluctuations can reach 5%-10%). At the same time, it is prone to problems such as insufficient or excessive material pressing, leading to blockage of the pressing chamber. Existing frequency converter control functions are limited and protection mechanisms are rudimentary: Some improved oil presses use frequency converters to achieve motor speed regulation, but this is only open-loop speed regulation and does not form a closed-loop control based on the pressing state; their protection functions are mostly single overcurrent protection - when the motor current exceeds the preset threshold, the machine stops directly, and it cannot distinguish between instantaneous overload (such as short-term large-scale feeding) and jamming faults, with a false shutdown rate of over 30%, and after shutdown, manual disassembly and cleaning of the pressing chamber is required, which takes time (usually 10-30 minutes) to resume production, seriously affecting the continuity of production. Poor reliability of jamming fault diagnosis: Existing anti-jamming technology (if it exists) is based solely on the single signal of motor current. When the material humidity fluctuates or the feed rate increases for a short period of time, a "false jamming" phenomenon of sudden current rise is likely to occur, leading to false alarms or false shutdowns. When a true jamming occurs (such as when material agglomerates and blocks the pressing chamber), the single current signal may be delayed in judgment due to the "slow rise of current" before the motor stalls, missing the best time to deal with the problem and aggravating equipment wear. In summary, existing technologies suffer from four major problems: low control precision, high fault misjudgment rate, low degree of automation, and high equipment wear and tear. There is an urgent need for an integrated control solution that can achieve constant pressure pressing, intelligent anti-jamming, and automatic recovery. Summary of the Invention

[0003] This invention aims to overcome the shortcomings of existing screw oil press control technology and provide a multi-signal fusion intelligent control method and system. The core objectives include: To achieve constant pressure pressing within the pressing chamber and stabilize the oil yield; Accurate identification of stuck faults based on multi-parameter fusion, reducing the false judgment rate; After a jamming failure occurs, the material is automatically ejected and recovered without manual intervention; Reduce mechanical impact on equipment, extend its service life, and reduce energy consumption.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A method for preventing jamming and controlling constant current in a multi-signal fusion screw oil press, characterized by the following steps: S100: Real-time acquisition of the working current signal I, output torque signal T, and real-time speed signal N of the main motor of the screw oil press, and preprocessing of the acquired signals; S200: The preprocessed current signal I is compared with the preset target current value I_set. The adjustment amount is calculated through the adaptive PID control algorithm, and the frequency converter is driven to dynamically adjust the motor speed so that I is stabilized near I_set, thereby achieving constant current control. S300: Based on the pre-processed current I, current change rate ΔI / Δt, torque T, and speed N, multi-signal fusion judgment is performed, and if all preset conditions are met, it is judged as a jamming fault; S400: If a jamming fault is detected, the control motor will perform a fully automatic material unloading operation, including reverse operation, pause buffering, and smooth restart, and restore the constant current control mode.

[0005] Furthermore, all preset conditions in step S300 include: current I > preset first threshold I_max, current change rate ΔI / Δt > preset second threshold ΔI0 / Δt, torque T > preset third threshold T_max, and rotational speed N < preset fourth threshold N_min.

[0006] Furthermore, the preprocessing in step S100 includes performing Kalman filtering, signal amplification, and A / D conversion on the acquired analog signal to obtain a stable digital signal.

[0007] Furthermore, the reverse operation in step S400 is specifically as follows: the motor runs at a preset torque T_back, which is 60%-80% of T_max, and at the same time runs at a preset reverse speed N_back, which is 40%-60% of the normal speed. The first duration t1 of the reverse operation is 1-3s.

[0008] Furthermore, in step S400, the pause buffer is to stop the motor and pause it, with the second pause duration t2 being 0.5-2s; the smooth restart is to smoothly accelerate the motor from 0 speed to normal operating speed.

[0009] Furthermore, the torque signal T in step S100 is directly acquired by a torque sensor or calculated using a current-speed mathematical model.

[0010] Furthermore, the target current value I_set is adaptively adjusted according to the type of oil extraction raw material, which includes rapeseed, peanuts, and soybeans.

[0011] Furthermore, the intelligent control system for a multi-signal fusion screw oil press, which implements the method of any one of claims 1-7, includes a signal detection module, a core control module, and an execution drive module; Signal detection module: including Hall current sensor, photoelectric speed sensor and optional torque sensor, used to collect motor current I, speed N and torque T; Core control module: including MCU / DSP microprocessor and data storage, used to run adaptive PID algorithm, multi-signal fusion judgment and instruction generation; Execution drive module: This is a vector frequency converter used to receive control commands and adjust the motor speed, direction, and torque.

[0012] Furthermore, it also includes a human-computer interaction module, which includes a touch screen, physical buttons, and an alarm unit; the touch screen is used to set the parameters of I_set and I_max and display real-time operating data, and the alarm unit is used to issue an audible and visual alarm when a jamming fault occurs.

[0013] Furthermore, the MCU / DSP microprocessor is an STM32F407 series chip, the Hall current sensor is an ACS712 series, and the vector inverter is a Delta VFD-VL series.

[0014] Compared with the prior art, the present invention has the following significant advantages: 1. Significantly improved oil yield: Through adaptive PID constant flow control, the pressing chamber pressure is stabilized at the optimal value, resulting in more thorough material pressing and an increase in oil yield of 3%-8%; 2. Extremely low fault misjudgment rate: The multi-signal fusion judgment mechanism (current + rate of change + torque + speed) reduces the misjudgment rate from more than 30% in existing technologies to less than 5%, ensuring production continuity; 3. Fully automated and unmanned operation: From diagnosis to recovery from a stuck fault, no manual operation is required. Downtime is reduced from the traditional 10-30 minutes to 3-5 seconds, and production efficiency is increased by more than 20%. 4. Extended equipment lifespan: Torque / speed limiting during reverse operation and smooth restart control prevent mechanical shock, extending the lifespan of the screw press, gearbox, and motor by 15%-20%. 5. Energy saving and consumption reduction: Constant current control avoids frequent fluctuations in motor between light load and overload, improves motor operating efficiency by 10%-15%, and reduces energy consumption per unit time by 8%-12%. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the implementation of the multi-signal fusion screw oil press anti-jamming and constant current control method of the present invention; Figure 2 The system framework diagram of the intelligent control system for a multi-signal fusion screw oil press, which implements the above method. Detailed Implementation

[0016] The present invention will now be described in more detail and in more complete form with reference to the accompanying drawings.

[0017] The present invention provides a multi-signal fusion intelligent anti-jamming and constant current control method and system for screw oil presses, characterized in that: I. A method for preventing jamming and maintaining constant current in a multi-signal fusion screw oil press, comprising the following steps: Step S100: Signal Acquisition and Preprocessing The signal detection module collects the working current signal I, output torque signal T (which can be calculated by the current-speed model or directly collected by the torque sensor), and real-time speed signal N of the main motor of the screw oil press in real time; the collected analog signals are filtered (such as Kalman filtering), amplified, and converted by A / D to remove noise interference, and a stable digital signal is obtained and transmitted to the core control module. Step S200: Constant flow control regulation (to achieve constant pressure pressing) The core control module compares the preprocessed current signal I with the preset target current value I_set (corresponding to the optimal pressing pressure), calculates the adjustment amount through an adaptive PID control algorithm, and outputs it to the execution drive module (frequency converter). The frequency converter dynamically changes the power supply frequency of the main motor according to the adjustment amount, thereby adjusting the motor speed—when I > I_set, the speed is reduced to decrease the pressing pressure; when I < I_set, the speed is increased to increase the pressing pressure, ultimately stabilizing the motor current near I_set, indirectly achieving constant pressure pressing in the pressing chamber. Step S300: Multi-signal fusion to determine stuck fault The core control module performs a fusion judgment on four parameters: pre-processed current I, current change rate ΔI / Δt, torque T, and speed N. A jamming fault is determined when all of the following conditions are met: Current I > preset first threshold I_max (e.g., 36A, corresponding to the critical current of motor stall). The rate of change of current ΔI / Δt is greater than the preset second threshold ΔI0 / Δt (e.g., 5A / s, excluding short-time overload). Torque T > preset third threshold T_max (e.g., 150 N·m, corresponding to the limit torque when the pressing chamber is blocked). Rotational speed N < preset fourth threshold N_min (e.g., 50 r / min, excluding normal low-speed operation); Step S400: Fully automatic material return and operation recovery If a jamming fault is detected, the core control module sends a material return command to the frequency converter and performs the following operations: (1) Reverse operation: Control the motor to run in reverse for a first duration t1 (e.g. 2s) with a set torque T_back (e.g., 70% of T_max to avoid mechanical impact) and a set reverse speed N_back (e.g., 50% of normal speed) to push the blocked material out of the pressing chamber; (2) Pause buffer: The motor stops running and pauses for a second duration t2 (e.g., 1s) to avoid secondary accumulation of materials; (3) Smooth restart: Control the motor to smoothly accelerate from 0 speed to normal operating speed, and re-enter the constant current control mode of step S200.

[0018] II. The intelligent control system for the multi-signal fusion screw oil press that implements the above method includes a signal detection module, a core control module, an execution drive module, and an optional human-machine interaction module. The functions of each module are as follows: Signal detection module: It consists of a Hall current sensor (such as the ACS712 model), a photoelectric speed sensor, and an optional strain gauge torque sensor. Its main function is to collect the current signal I, speed signal N, and torque signal T during motor operation, and output the collected analog signals to the core control module. Core control module: It includes a microprocessor (which can be an MCU or DSP type, such as the STM32F407 model), a data memory and a clock module. Its core function is to run the adaptive PID algorithm and multi-signal fusion judgment logic in the control method, and at the same time generate and send control commands to the execution drive module. Execution driver module: Specifically, vector inverters (such as Delta VFD-VL series) are used to receive commands from the core control module and adjust the power supply frequency and voltage to achieve precise regulation of motor speed, direction and output torque. Human-computer interaction module (optional): Composed of a touch screen (such as a TFT-LCD type), physical buttons, and a buzzer alarm unit, it can be used to manually set core parameters such as target current value I_set and current threshold I_max, display motor current, speed and other operating data in real time, and issue an alarm prompt through the buzzer when the equipment jams.

[0019] The optimal implementation of this invention is described in detail below, taking into account specific hardware selections and parameters: 1. Hardware Selection Core control module: Employs an STM32F407ZGT6 microprocessor (168MHz clock speed, supports multi-channel ADC sampling to meet real-time control requirements); data storage uses a 16GB SD card to store historical operating data; Signal detection module: The current sensor is ACS712-50A (range ±50A, accuracy ±1.5%), the speed sensor is E6B2-CWZ6C (resolution 1000P / R, response frequency 50kHz), and the torque sensor is HCNJ-105 (range 0-300N・m, accuracy ±0.5%). Drive module: Delta VFD-VL220CP frequency converter (rated power 2.2kW, supports vector control, and can achieve precise speed / torque adjustment). Human-computer interaction module: adopts a 7-inch TFT touch screen (resolution 800×480), supports parameter setting and data display; the buzzer is a 5V active buzzer with an alarm volume ≥85dB. 2. Key parameter settings Configure the following core parameters through the human-computer interaction module: Target current I_set = 28A (corresponding to the optimal pressing pressure for rapeseed oil extraction); Current threshold I_max = 36A (motor stall critical current); The threshold for the rate of change of current is ΔI / Δt = 5 A / s; Torque threshold T_max = 150 N·m; Rotational speed threshold N_min = 50 r / min; Reverse operation parameters: T_back=105N・m (70% of T_max), N_back=100r / min (50% of normal speed 200r / min), t1=2s; Pause duration t2 = 1 second. 3. Complete Workflow Example Normal constant current operation: After the system starts, the motor runs normally at 200r / min. The current sensor collects the current I=28A (consistent with I_set), the speed N=200r / min, and the torque T=80N・m. The core control module maintains the parameters stable through the PID algorithm, and the oil press produces oil normally. A jamming fault occurred: Due to a large amount of wet rapeseed being fed into the feed inlet for a short period of time, the pressing chamber became blocked. The current I rose to 38A (>I_max=36A) within 0.5 seconds, ΔI / Δt=6A / s (>5A / s), the torque T rose to 160N・m (>T_max=150N・m), and the speed N dropped to 45r / min (<N_min=50r / min). The core control module determined that a jamming fault occurred, and the buzzer sounded an alarm. Fully automatic unloading: The frequency converter receives the command and controls the motor to run in reverse for 2 seconds at T_back=105N・m and N_back=100r / min to push out the blocked rapeseed; then the motor pauses for 1 second; Resumption of operation: The motor smoothly accelerates from 0 to 200 r / min, the current gradually rises back to 28A, and it re-enters the constant current control mode. The alarm stops, and the oil press resumes normal operation.

[0020] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preventing jamming and controlling constant current in a multi-signal fusion screw oil press, characterized in that, Includes the following steps: S100: Real-time acquisition of the working current signal I, output torque signal T, and real-time speed signal N of the main motor of the screw oil press, and preprocessing of the acquired signals; S200: The preprocessed current signal I is compared with the preset target current value I_set. The adjustment amount is calculated through the adaptive PID control algorithm, and the frequency converter is driven to dynamically adjust the motor speed so that I is stabilized near I_set, thereby achieving constant current control. S300: Based on the pre-processed current I, current change rate ΔI / Δt, torque T, and speed N, multi-signal fusion judgment is performed, and if all preset conditions are met, it is judged as a jamming fault; S400: If a jamming fault is detected, the control motor will perform a fully automatic material unloading operation, including reverse operation, pause buffering, and smooth restart, and restore the constant current control mode.

2. The multi-signal fusion screw oil press anti-jamming and constant current control method according to claim 1, characterized in that: All preset conditions in step S300 include: current I > preset first threshold I_max, current change rate ΔI / Δt > preset second threshold ΔI0 / Δt, torque T > preset third threshold T_max, and rotational speed N < preset fourth threshold N_min.

3. The multi-signal fusion screw oil press anti-jamming and constant current control method according to claim 1, characterized in that: The preprocessing in step S100 includes Kalman filtering, signal amplification, and A / D conversion of the acquired analog signal to obtain a stable digital signal.

4. The multi-signal fusion screw oil press anti-jamming and constant current control method according to claim 1, characterized in that: The reverse operation in step S400 is as follows: the motor runs at a preset torque T_back, which is 60%-80% of T_max, and at the same time runs at a preset reverse speed N_back, which is 40%-60% of the normal speed. The first duration t1 of the reverse operation is 1-3s.

5. The multi-signal fusion screw oil press anti-jamming and constant current control method according to claim 4, characterized in that: The pause buffer in step S400 is to stop the motor and pause it, with the second pause duration t2 being 0.5-2s; the smooth restart is to smoothly accelerate the motor from 0 speed to normal operating speed.

6. The method for preventing jamming and maintaining constant current in a multi-signal fusion screw oil press according to claim 1, characterized in that: The torque signal T in step S100 is directly acquired by a torque sensor or calculated by a current-speed mathematical model.

7. The method for preventing jamming and maintaining constant current in a multi-signal fusion screw oil press according to claim 1, characterized in that: The target current value I_set is adaptively adjusted according to the type of oil extraction raw material, which includes rapeseed, peanuts, and soybeans.

8. A multi-signal fusion intelligent control system for a screw oil press that implements the method of any one of claims 1-7, characterized in that: It includes a signal detection module, a core control module, and an execution driver module; Signal detection module: including Hall current sensor, photoelectric speed sensor and optional torque sensor, used to collect motor current I, speed N and torque T; Core control module: including MCU / DSP microprocessor and data storage, used to run adaptive PID algorithm, multi-signal fusion judgment and instruction generation; Execution drive module: This is a vector frequency converter used to receive control commands and adjust the motor speed, direction, and torque.

9. The system according to claim 8, characterized in that: It also includes a human-computer interaction module, which includes a touch screen, physical buttons and an alarm unit; the touch screen is used to set the parameters of I_set and I_max and display real-time operating data, and the alarm unit is used to issue an audible and visual alarm when a jamming fault occurs.

10. The system according to claim 8, characterized in that: The MCU / DSP microprocessor is an STM32F407 series chip, the Hall current sensor is an ACS712 series, and the vector inverter is a Delta VFD-VL series.

Images