Precise feed dosing control device based on PLC and closed-loop stepping motor

Abstract

The utility model discloses a precise feed dosing control device based on a PLC (Programmable Logic Controller) and a closed-loop stepping motor, which is characterized in that a main control module is connected with a driving module, a sensor module, a man-machine interaction module and a time sequence chain circuit, and a power supply module is connected with the main control module, the driving module, the sensor module and the man-machine interaction module. By means of the high-precision sensor and the precise signal processing circuit, precise control over feed dosing is achieved, and the feed quality is powerfully improved. In order to guarantee the reliability, a triple anti-misoperation mechanism including hardware-level protection, software verification and time sequence interlocking is adopted, and mistaken dosing and equipment faults are effectively avoided. In the anti-interference aspect, various measures such as optical coupler isolation, communication isolation chips and EMI filters are applied to all the modules, and the influence of external interference is reduced. In addition, an HMI touch screen is arranged, so that an operator can conveniently set parameters and check the equipment state, an audible and visual alarm function can also remind abnormity in time, and friendly man-machine interaction is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of control technology and relates to a feed precision dosing control device based on PLC and closed-loop stepper motor. Background Technology

[0002] In feed production, precise medication dosing is crucial for feed quality and animal health. However, existing feed medication control devices suffer from numerous problems. On the one hand, the dosing accuracy is unsatisfactory. The devices themselves have limited metering precision and are easily affected by external factors such as changes in temperature and humidity in the production environment, as well as uneven material flow, leading to large fluctuations in feed medication content. Too little medication cannot guarantee animal health; too much is wasteful and may even poison animals. On the other hand, existing devices have weak anti-interference and error prevention capabilities. Electromagnetic interference and mechanical vibrations in the production site often affect the sensors and controllers of the devices, compromising dosing accuracy. Moreover, there is a lack of effective error prevention mechanisms to correct operator errors or hardware / software malfunctions. Unstable feed medication content not only hinders animal growth and causes economic losses to the livestock industry, but excessive medication also pollutes the environment. Summary of the Invention

[0003] To address the problems existing in the background technology, this utility model proposes a feed precision dosing control device based on PLC and closed-loop stepper motor.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A feed precision dosing control device based on PLC and closed-loop stepper motor, characterized in that it includes: a main control module, a drive module, a sensor module, a human-machine interaction module, a power supply module, and a timing interlock circuit;

[0006] The main control module is connected to the drive module, sensor module, human-machine interaction module, and timing interlock circuit, respectively, and the power supply module is connected to the main control module, drive module, sensor module, and human-machine interaction module, respectively.

[0007] Furthermore, the main control module includes: a PLC controller, an AD620 instrumentation amplifier, an OP07 operational amplifier, a low-pass filter, resistors R1 and R2, capacitors C1 and C2, a bidirectional TVS diode, and an expansion module.

[0008] The AD620 instrumentation amplifier is connected to a low-pass filter, which is then connected to a PLC controller. The RG1 pin of the AD620 instrumentation amplifier is connected to one end of resistor R1, and the other end of resistor R1 is connected to the RG2 pin of the AD620 instrumentation amplifier. The power supply pin of the AD620 instrumentation amplifier is connected to a power module. The output pin of the AD620 instrumentation amplifier is connected to one end of capacitor C1 and the IN- pin of the OP07 operational amplifier. The other end of capacitor C1 is connected to ground. The IN- pin of the OP07 operational amplifier is connected to one end of resistor R2, and the other end of resistor R2 is connected to the output pin of the OP07 operational amplifier. The IN+ pin of the OP07 operational amplifier is grounded. The output pin of the OP07 operational amplifier is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the IN- pin of the OP07 operational amplifier. The output pin of the OP07 operational amplifier is connected to the analog input port of the PLC controller. The anode of the bidirectional TVS diode is connected to the IN+ pin and ground of the AD620 instrumentation amplifier. The cathode of the bidirectional TVS diode is connected to the IN- pin and ground of the AD620 instrumentation amplifier. The power input terminal of the PLC controller is connected to the power module. The ground terminal of the PLC controller is connected to ground. The PLC controller is connected to the expansion module through the backplane bus.

[0009] Furthermore, the drive module includes: a closed-loop stepper driver, a current sensor, a voltage comparator, a MOSFET Q1, a potentiometer, a switching diode, a high-speed optocoupler, resistors R3, R4, and R5;

[0010] The anode of the high-speed optocoupler is connected to one end of resistor R3, and the other end of resistor R3 is connected to the pulse output port of the PLC controller. The cathode of the high-speed optocoupler is grounded. The output port of the high-speed optocoupler is connected to the PUL+ port of the closed-loop stepper driver. The power port of the high-speed optocoupler is connected to the power module. The power port of the current sensor is connected to the power module. The ground terminal of the current sensor is connected to ground. The output terminal of the current sensor is connected to one end of resistor R4. The other end of resistor R4 is connected to the non-inverting input terminal of the voltage comparator. The IP+ port of the current sensor is connected to the positive power supply terminal of the closed-loop stepper driver and the drain of MOSFET Q1. The IP- port of the current sensor is connected to the negative power supply terminal of the closed-loop stepper driver. The inverting input terminal of the voltage comparator is connected to the potentiometer. The output terminal of the voltage comparator is connected to one end of the switching diode. The other end of the switching diode is connected to the gate of MOSFET Q1. The power port of the voltage comparator is connected to the power module. The ground terminal of the voltage comparator is connected to ground. The gate of MOSFET Q1 is connected to one end of resistor R5. The other end of resistor R5 is connected to ground. The source of MOSFET Q1 is connected to ground.

[0011] Furthermore, the sensor module includes: a weighing sensor, an ADC analog-to-digital converter, a flow meter, a current loop receiver, a temperature sensor, and a resistor R6;

[0012] The EXC+ pin of the load cell is connected to the power module, and the EXC- pin is connected to ground. The positive signal output terminal of the load cell is connected to the positive analog signal input terminal of the ADC and the non-inverting input terminal of the AD620 instrumentation amplifier. The negative signal output terminal of the load cell is connected to the negative analog signal input terminal of the ADC and the inverting input terminal of the AD620 instrumentation amplifier. The power input terminal of the ADC is connected to the power module. The ground terminal of the ADC is connected to ground. The clock signal input terminal of the ADC is connected to the digital output port of the PLC controller. The data output terminal of the ADC is connected to the digital input port of the PLC controller. The positive terminal of the flow meter is connected to the positive current input terminal of the current loop receiver. The negative terminal of the flow meter is connected to the negative current input terminal of the current loop receiver. The output terminal of the current loop receiver is connected to the analog input channel of the PLC controller. The data input terminal of the temperature sensor is connected to the digital input port of the PLC controller and one end of resistor R6. The other end of resistor R6 is connected to the power port. The ground terminal of the temperature sensor is connected to ground. The positive power terminal of the temperature sensor is connected to the power port.

[0013] Furthermore, the human-computer interaction module includes: an HMI touchscreen, a communication isolation chip, a Darlington array, a buzzer, an LED light, and a resistor R7;

[0014] The VDD1 and VDD2 terminals of the communication isolation chip are connected to the power module; the GND1 and GND2 terminals of the communication isolation chip are connected to ground; the receive output terminal of the communication isolation chip is connected to the receive data pin of the HMI touchscreen; the transmit input terminal of the communication isolation chip is connected to the transmit data pin of the HMI touchscreen; the IN1 and IN2 pins of the Darlington array are connected to the digital output port of the PLC controller; the COM pin of the Darlington array is connected to the power port; the OUT1 pin of the Darlington array is connected to the positive terminal of the buzzer; the negative terminal of the buzzer is connected to ground; the OUT2 pin of the Darlington array is connected to one end of resistor R7; the other end of resistor R7 is connected to the anode of the LED; and the cathode of the LED is connected to ground.

[0015] Furthermore, the sequential continuous circuit includes: an RS flip-flop;

[0016] The data input pin of the RS flip-flop is connected to the pulse output port of the PLC controller, the clock signal pin of the RS flip-flop is connected to the enable signal pin of the PLC controller, and the output pin of the RS flip-flop is connected to the PUL+ port of the closed-loop stepper driver.

[0017] Furthermore, the power module includes: an EMI filter, an AC / DC converter, an LM2596 step-down circuit, a TPS7A4700 step-down circuit, a resistor R8, a fuse F1, a ferrite bead, a capacitor C3, a capacitor C4, a resistor R9, and a resistor R10.

[0018] The live wire terminal of the EMI filter is connected to the live wire of the 220V AC power supply, and the neutral wire terminal is also connected to the neutral wire. Resistor R8 is connected in series between the live and neutral wire terminals of the EMI filter. The protective ground terminal of the EMI filter is connected to ground. The output terminal of the EMI filter is connected to the input terminal of the AC / DC converter. The output terminal of the AC / DC converter is connected to the power supply terminal of the PLC, the power input terminal of the closed-loop stepper driver, the COM pin of the Darlington array, the input voltage pin of the LM2596 step-down circuit, one end of the ferrite bead, and one end of capacitor C3. The other end of capacitor C3 is connected to ground. The other end of the ferrite bead is connected to one end of fuse F1 and one end of capacitor C4. The other end of capacitor C4 is connected to ground. The other end of fuse F1 is connected to the input of the LM2596 step-down circuit. The voltage pin connections are as follows: the output voltage pin of the LM2596 step-down circuit is connected to the power supply pins of the AD620 instrumentation amplifier, the OP07 operational amplifier, the low-pass filter, the high-speed optocoupler, and the input voltage pin of the TPS7A4700 step-down circuit; the feedback pin of the LM2596 step-down circuit is connected to one end of resistor R9; the other end of resistor R9 is connected to one end of resistor R10; the other end of resistor R10 is connected to ground; the output voltage pin of the TPS7A4700 step-down circuit is connected to the power supply pins of the temperature sensor and the ADC analog-to-digital converter; the output of the AC / DC converter is connected to one end of the ferrite bead and one end of capacitor C3; the other end of capacitor C3 is connected to ground; the other end of the ferrite bead is connected to one end of fuse F1 and one end of capacitor C4; the other end of capacitor C4 is connected to ground.

[0019] Compared with existing technologies, this utility model has the following advantages: The feed dosing control device has significant advantages in terms of precise dosing, reliability, anti-interference, and human-machine interaction. It utilizes high-precision sensors and precise signal processing circuits to achieve precise control of feed dosing, effectively improving feed quality. To ensure reliability, a triple anti-misoperation mechanism including hardware-level protection, software verification, and timing interlocks is adopted to effectively avoid accidental dosing and equipment failure. In terms of anti-interference, each module employs various measures such as optical coupling isolation, communication isolation chips, and EMI filters to reduce the impact of external interference. Furthermore, it is equipped with an HMI touchscreen for convenient parameter setting and equipment status viewing, and the audible and visual alarm function can promptly alert to abnormalities, achieving a user-friendly human-machine interaction. Attached Figure Description

[0020] Figure 1 This is the main block diagram of a feed precision dosing control device based on PLC and closed-loop stepper motor according to this utility model.

[0021] Figure 2 This is the circuit connection diagram of the main control module described in this utility model;

[0022] Figure 3 This is a circuit connection diagram of the drive module described in this utility model;

[0023] Figure 4 This is a circuit connection diagram of the sensor module described in this utility model;

[0024] Figure 5 This is a circuit connection diagram of the human-computer interaction module described in this utility model;

[0025] Figure 6 This is a circuit connection diagram of the power module described in this utility model;

[0026] Figure 7 This is a connection diagram of the sequential continuous circuit described in this utility model;

[0027] Figure 8 This is a structural diagram of a feed dosing mechanism in existing technology.

[0028] 1. Closed-loop stepper driver; 2. Stirring motor; 3. Screw motor; 4. Temperature sensor; 5. Weighing sensor. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] like Figures 1-8 As shown, the technical solution adopted by this utility model is as follows: a feed precision dosing control device based on PLC and closed-loop stepper motor, including: a main control module, a drive module, a sensor module, a human-machine interaction module, a power supply module, and a timing interlock circuit.

[0031] The main control module is connected to the drive module, sensor module, human-machine interaction module, and timing interlock circuit, respectively, and the power supply module is connected to the main control module, drive module, sensor module, and human-machine interaction module, respectively.

[0032] The main control module includes: PLC controller, AD620 instrumentation amplifier, OP07 operational amplifier, low-pass filter, resistor R1, resistor R2, capacitor C1, capacitor C2, bidirectional TVS diode, and expansion module.

[0033] The AD620 instrumentation amplifier is connected to a low-pass filter, which is then connected to a PLC controller. The RG1 pin of the AD620 instrumentation amplifier is connected to one end of resistor R1, and the other end of resistor R1 is connected to the RG2 pin of the AD620 instrumentation amplifier. The power supply pin of the AD620 instrumentation amplifier is connected to a power module. The output pin of the AD620 instrumentation amplifier is connected to one end of capacitor C1 and the IN- pin of the OP07 operational amplifier. The other end of capacitor C1 is connected to ground. The IN- pin of the OP07 operational amplifier is connected to one end of resistor R2, and the other end of resistor R2 is connected to the output pin of the OP07 operational amplifier. The IN+ pin of the OP07 operational amplifier is grounded. The output pin of the OP07 operational amplifier is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the IN- pin of the OP07 operational amplifier. The output pin of the OP07 operational amplifier is connected to the analog input port of the PLC controller. The anode of the bidirectional TVS diode is connected to the IN+ pin and ground of the AD620 instrumentation amplifier. The cathode of the bidirectional TVS diode is connected to the IN- pin and ground of the AD620 instrumentation amplifier. The power input terminal of the PLC controller is connected to the power module. The ground terminal of the PLC controller is connected to ground. The PLC controller is connected to the expansion module through the backplane bus.

[0034] The main control module is based on a PLC controller, specifically a Siemens S7-1200 CPU 1214C DC / DC / DC type PLC. It receives analog and digital signals from the sensor module, processes them internally, and outputs control signals to the drive module, while also communicating with the human-machine interface module. The module amplifies and filters the weak sensor signals using an AD620 instrumentation amplifier, an OP07 operational amplifier, a low-pass filter, resistors R1 and R2, capacitors C1 and C2, and a bidirectional TVS diode. An expansion module adds analog input channels.

[0035] The main control module is responsible for the control logic processing of the entire device and coordinates the work of each module. It processes sensor data, determines the dosing status, controls the stepper motor to achieve precise dosing, and interacts with the operator through the human-machine interface module, receiving parameter settings and providing feedback on the device's status.

[0036] The PLC controller processes and stores data, executes control programs, and automates the dosing process. It connects to other modules via different ports to enable signal input / output and integrate with the device.

[0037] The AD620 instrumentation amplifier amplifies the weak signal output from the load cell 5, increasing the signal strength for easier subsequent processing.

[0038] The OP07 operational amplifier, together with resistors R1 and R2, and capacitors C1 and C2, constitutes a second-order Butterworth low-pass filter, which filters out high-frequency noise in the signal and improves signal quality.

[0039] The expansion module uses the SM1231 analog input module to expand the PLC's analog input channels, enabling the device to connect to more analog sensors, such as flow meter signals.

[0040] The drive module includes: closed-loop stepper driver 1, current sensor, voltage comparator, MOSFET Q1, potentiometer, switching diode, high-speed optocoupler, resistor R3, resistor R4, and resistor R5;

[0041] The anode of the high-speed optocoupler is connected to one end of resistor R3, and the other end of resistor R3 is connected to the pulse output port of the PLC controller. The cathode of the high-speed optocoupler is grounded. The output port of the high-speed optocoupler is connected to the PUL+ port of the closed-loop stepper driver 1. The power port of the high-speed optocoupler is connected to the power module. The power port of the current sensor is connected to the power module. The ground terminal of the current sensor is connected to ground. The output terminal of the current sensor is connected to one end of resistor R4. The other end of resistor R4 is connected to the non-inverting input terminal of the voltage comparator. The IP+ port of the current sensor is connected to the closed-loop stepper driver 1. The positive power supply terminal of driver 1 and the drain terminal of MOSFET Q1 are connected. The IP-port of the current sensor is connected to the negative power supply terminal of closed-loop stepper driver 1. The inverting input terminal of the voltage comparator is connected to the potentiometer. The output terminal of the voltage comparator is connected to one end of the switching diode. The other end of the switching diode is connected to the gate of MOSFET Q1. The power supply port of the voltage comparator is connected to the power module. The ground terminal of the voltage comparator is connected to ground. The gate of MOSFET Q1 is connected to one end of resistor R5. The other end of resistor R5 is connected to ground. The source of MOSFET Q1 is connected to ground.

[0042] The drive module receives pulse signals from the main control module and drives the stepper motor through the closed-loop stepper driver 1. The drive module precisely controls the speed and angle of the stepper motor to achieve accurate drug dosing. At the same time, the current sensor monitors the motor current. When the current is abnormal, the overcurrent protection circuit activates to cut off the power supply and ensure the safe operation of the equipment.

[0043] The closed-loop stepper driver 1 uses the Leadshine CL3-EC closed-loop stepper driver to drive the stepper motor and control the motor's operating status.

[0044] The current sensor uses the ACS712 ELCTR-20A current sensor to monitor the motor current and convert the current signal into a voltage signal output to determine the motor's operating status.

[0045] The voltage comparator uses an LM393 voltage comparator to compare the voltage signal output by the current sensor with a set threshold. When the current exceeds the threshold, the output signal triggers overcurrent protection.

[0046] The MOSFET Q1 uses an IRF540 MOSFET and acts as a switching element in the overcurrent protection circuit. When an overcurrent is detected, it cuts off the driver power supply to protect the motor and the closed-loop stepper driver 1.

[0047] The high-speed optocoupler uses the 6N137 high-speed optocoupler to isolate the signals of the main control module and the drive module, prevent interference, and ensure the stability of signal transmission.

[0048] The sensor module includes: a weighing sensor 5, an ADC analog-to-digital converter, a flow meter, a current loop receiver, a temperature sensor 4, and a resistor R6;

[0049] The EXC+ pin of load cell 5 is connected to the power supply module, and the EXC- pin is connected to ground. The positive output terminal of load cell 5 is connected to the positive analog input terminal of the ADC and the non-inverting input terminal of the AD620 instrumentation amplifier. The negative output terminal of load cell 5 is connected to the negative analog input terminal of the ADC and the inverting input terminal of the AD620 instrumentation amplifier. The power input terminal of the ADC is connected to the power supply module, the ground terminal of the ADC is connected to ground, and the clock signal input terminal of the ADC is connected to the PLC control. The digital output port of the device is connected, the data output terminal of the ADC analog-to-digital converter is connected to the digital input port of the PLC controller, the positive terminal of the flow meter is connected to the positive current input terminal of the current loop receiver, the negative terminal of the flow meter is connected to the negative current input terminal of the current loop receiver, the output terminal of the current loop receiver is connected to the analog input channel of the PLC controller, the data input terminal of the temperature sensor 4 is connected to the digital input port of the PLC controller, one end of the resistor R6 is connected, the other end of the resistor R6 is connected to the power supply port, the ground terminal of the temperature sensor 4 is connected to ground, and the positive power supply terminal of the temperature sensor 4 is connected to the power supply port.

[0050] Weighing sensor 5 converts the dosage weight into an electrical signal, which is then converted by an ADC (Analog-to-Digital Converter) and transmitted to the PLC controller. Flow meter converts flow rate into an electrical signal, which is processed by a current loop receiver and input to the PLC controller. Temperature sensor 4 monitors the ambient temperature in real time and transmits the data. The sensor module collects key data during the dosing process in real time, providing a basis for precise dosing and equipment control.

[0051] Weighing sensor 5 uses the HBM Z6FC3 weighing sensor, which converts the dosage weight into a weak electrical signal output, and is a key component for monitoring the dosage weight.

[0052] The ADC analog-to-digital converter uses an HX711 24-bit ADC to convert the analog signal from the weighing sensor 5 into a digital signal, which is easier for the PLC controller to process and improves the measurement accuracy.

[0053] The flow meter uses an LWGY-10 turbine flow meter to measure the dosing flow rate and converts the flow rate into a current signal output.

[0054] The current loop receiver converts the flow meter's current signal into a voltage signal, which is compatible with the analog input of the PLC controller.

[0055] Temperature sensor 4 uses a DS18B20 temperature sensor to monitor the ambient temperature in real time, convert the temperature into a digital signal and transmit it to the PLC controller for environmental status monitoring.

[0056] The human-computer interaction module includes: HMI touch screen, communication isolation chip, Darlington array, buzzer, LED light, and resistor R7;

[0057] The VDD1 and VDD2 terminals of the communication isolation chip are connected to the power module; the GND1 and GND2 terminals of the communication isolation chip are connected to ground; the receive output terminal of the communication isolation chip is connected to the receive data pin of the HMI touchscreen; the transmit input terminal of the communication isolation chip is connected to the transmit data pin of the HMI touchscreen; the IN1 and IN2 pins of the Darlington array are connected to the digital output port of the PLC controller; the COM pin of the Darlington array is connected to the power port; the OUT1 pin of the Darlington array is connected to the positive terminal of the buzzer; the negative terminal of the buzzer is connected to ground; the OUT2 pin of the Darlington array is connected to one end of resistor R7; the other end of resistor R7 is connected to the anode of the LED; and the cathode of the LED is connected to ground.

[0058] The human-machine interface module enables operators to interact with the device through an HMI touchscreen. A communication isolation chip ensures stable communication, and LED lights and a buzzer sound an alarm when the device malfunctions.

[0059] The human-machine interface module provides a convenient operating interface, making it easy for operators to set parameters and view the status of the device; it also provides timely alarms when the device malfunctions, reminding operators to take action.

[0060] The HMI touchscreen uses the DisplayControl T-series HMI touchscreen to enable human-machine interaction for parameter setting, data display, and device status monitoring.

[0061] The communication isolation chip includes the ADM2483BRWZ communication isolation chip, which isolates the communication signals between the HMI touch screen and the PLC controller, enhances the anti-interference capability of communication, and ensures accurate data transmission.

[0062] The Darlington array uses the ULN2003 Darlington array to amplify the output signal of the PLC controller, drive the buzzer and LED lights, and realize the sound and light alarm function.

[0063] The buzzer is an LTE-1101DB buzzer, and the LED light is a high-brightness red LED. When the device malfunctions, the LTE-1101DB buzzer and the high-brightness red LED will emit an audible and visual alarm to attract the operator's attention.

[0064] The power supply module includes: EMI filter, AC / DC converter, LM2596 step-down circuit, TPS7A4700 step-down circuit, resistor R8, fuse F1, ferrite bead, capacitor C3, capacitor C4, resistor R9, and resistor R10.

[0065] The live wire terminal of the EMI filter is connected to the live wire of the 220V AC power supply, and the neutral wire terminal is connected to the neutral wire of the 220V AC power supply. Resistor R8 is connected in series between the live and neutral wire terminals of the EMI filter. The protective ground terminal of the EMI filter is connected to ground. The output terminal of the EMI filter is connected to the input terminal of the AC / DC converter. The output terminal of the AC / DC converter is connected to the power supply terminal of the PLC, the power input terminal of the closed-loop stepper driver 1, the COM pin of the Darlington array, the input voltage pin of the LM2596 step-down circuit, one end of the ferrite bead, and one end of capacitor C3. The other end of capacitor C3 is connected to ground. The other end of the ferrite bead is connected to one end of fuse F1 and one end of capacitor C4. The other end of capacitor C4 is connected to ground. The other end of fuse F1 is connected to the input of the LM2596 step-down circuit. The voltage pins are connected as follows: the output voltage pin of the LM2596 step-down circuit is connected to the power supply pins of the AD620 instrumentation amplifier, the OP07 operational amplifier, the low-pass filter, the high-speed optocoupler, and the input voltage pin of the TPS7A4700 step-down circuit; the feedback pin of the LM2596 step-down circuit is connected to one end of resistor R9; the other end of resistor R9 is connected to one end of resistor R10; the other end of resistor R10 is connected to ground; the output voltage pin of the TPS7A4700 step-down circuit is connected to the power supply pins of temperature sensor 4 and the ADC analog-to-digital converter; the output of the AC / DC converter is connected to one end of the ferrite bead and one end of capacitor C3; the other end of capacitor C3 is connected to ground; the other end of the ferrite bead is connected to one end of fuse F1 and one end of capacitor C4; the other end of capacitor C4 is connected to ground.

[0066] The power module filters, converts, and regulates the 220V AC power to provide stable 24V, 5V, and 3.3V DC power to each module. Providing a stable and reliable power supply for the entire device is the fundamental guarantee for its normal operation.

[0067] The EMI filter uses the SCHURTER DA12 EMI filter: to filter out electromagnetic interference in the power grid and improve power quality.

[0068] Mean Well NES-100-24AC / DC converter: Converts 220V AC power to 24V DC power to power drive modules and PLC controllers.

[0069] The LM2596 step-down circuit uses the LM2596-5.0 step-down chip to step down the 24V voltage to 5V, providing power to some sensors and circuits.

[0070] The TPS7A4700 step-down circuit uses a TPS7A4700 LDO to regulate the 5V voltage to 3.3V, providing power to components with high voltage stability requirements.

[0071] Resistor R8 is a varistor to prevent overvoltage damage to the equipment; resettable fuse F1 cuts off the circuit in case of overcurrent and automatically resets after the fault is cleared; ferrite bead, capacitor C3, and capacitor C4 further filter out ripple and noise in the power supply and improve power supply stability.

[0072] Sequential continuous circuits include: RS flip-flops.

[0073] The data input pin of the RS flip-flop is connected to the pulse output port of the PLC controller, the clock signal pin of RS is connected to the enable signal pin of the PLC controller, and the output pin of the RS flip-flop is connected to the PUL+ port of the closed-loop stepper driver 1.

[0074] Among them, a feed precision dosing control device based on PLC and closed-loop stepper motor also has a triple anti-misoperation mechanism: hardware-level protection, software-level verification, and timing interlock.

[0075] Hardware-level protection: Implemented through an ACS712 current sensor, an LM393 comparator, and an IRF540N MOSFET. When the motor current exceeds the set value, the comparator output signal turns off the IRF540N MOSFET, cutting off the driver power supply and protecting the device.

[0076] Software-level verification: The PLC controller's built-in program cross-compares the data from the weighing sensor 5 and the flow meter. If the deviation exceeds 5%, an alarm is triggered to prevent excessive dosing errors.

[0077] Timing Interlock: Using a 74HC74 RS trigger, the dosing pulse signal of the PLC controller is interlocked with the enable signal of the driver, ensuring that the motor cannot receive pulses when it is not enabled, thus avoiding malfunctions.

[0078] The feed dosing mechanism uses existing conventional technology, and its structure is as follows: Figure 8 As shown.

[0079] The existing feed dosing mechanism includes an auger driven by an auger motor 3, with a drug storage container installed above the auger. After the drug in the storage container is thoroughly mixed, it is conveyed by the auger to the feed mixer.

[0080] The weighing sensor 5 is installed on the support structure of the drug storage container to monitor changes in drug weight in real time and provide accurate feedback on the dosage.

[0081] Temperature sensor 4 is installed on the inner wall of the drug storage container to monitor the ambient temperature in real time and compensate for the impact of temperature on weighing accuracy.

[0082] The closed-loop stepper driver 1 is used to control the auger motor 3 and the stirring motor 2. The closed-loop stepper driver 1 is integrated at the rear end of the auger motor 3 and the stirring motor 2 to provide real-time feedback on motor speed, position and load status.

[0083] The ACS712 current sensor, LM393 comparator, and IRF540N MOSFET are installed in the driver power input circuit to monitor the motor current in real time and cut off the power supply when overloaded.

[0084] The PLC controller outputs pulses to a high-speed optocoupler, which then drives the closed-loop stepper driver 1 after isolation. The closed-loop stepper driver 1 provides real-time feedback on the auger speed, and the PLC controller adjusts the pulse frequency.

[0085] Weighing sensor 5 monitors the weight of the drug storage container. The PLC controller calculates the number of times the auger rotates based on the target dosage. Weighing sensor 6 detects the flow rate. If the flow rate is below the threshold, a buzzer is triggered.

[0086] The stirring motor 2 and the auger motor 3 operate synchronously. The PLC outputs a direction signal to proportionally control the stirring speed and the drug delivery speed. When the ACS712 current sensor detects an abnormal increase in the operating current of the feed dosing mechanism, it triggers the IRF540NMOSFET to cut off the power supply and activates the redundant drive channel.

[0087] During the operation of the precision feed dosing control device, 220V AC power is processed by the power supply module to output 24V, 5V, and 3.3V DC power to supply each module. The weighing sensor 5, flow meter, and temperature sensor 4 of the sensor module collect real-time data on the weight of the dosing, the flow rate, and the ambient temperature. The signal from the weighing sensor 5 is converted by an HX711 converter, and the signals from other sensors are conditioned before being transmitted to the main control module. The PLC controller of the main control module analyzes and processes the data, compares it with preset values ​​to calculate the deviation, and uses pulse signals via optocoupler isolation to control the stepper driver of the drive module, thereby driving the stepper motor for precise dosing. Simultaneously, a current sensor monitors the motor current, and the overcurrent protection circuit activates in case of abnormalities. Operators can set parameters and view the status through the touchscreen of the human-machine interface module. The device also triggers audible and visual alarms in case of malfunctions. Furthermore, the device employs a triple anti-misdosing mechanism—hardware-level, software-level, and timing interlock—to ensure accurate and reliable dosing and prevent accidental dosing.

[0088] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A feed precision dosing control device based on PLC and closed-loop stepper motor, characterized in that, It includes: main control module, drive module, sensor module, human-machine interaction module, power supply module, and timing interlock circuit; The main control module is connected to the drive module, sensor module, human-machine interaction module, and timing interlock circuit, respectively, and the power supply module is connected to the main control module, drive module, sensor module, and human-machine interaction module, respectively.

2. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 1, characterized in that, The main control module includes: PLC controller, AD620 instrumentation amplifier, OP07 operational amplifier, low-pass filter, resistor R1, resistor R2, capacitor C1, capacitor C2, bidirectional TVS diode, and expansion module; The AD620 instrumentation amplifier is connected to a low-pass filter, which is then connected to a PLC controller. The RG1 pin of the AD620 instrumentation amplifier is connected to one end of resistor R1, and the other end of resistor R1 is connected to the RG2 pin of the AD620 instrumentation amplifier. The power supply pin of the AD620 instrumentation amplifier is connected to a power module. The output pin of the AD620 instrumentation amplifier is connected to one end of capacitor C1 and the IN- pin of the OP07 operational amplifier. The other end of capacitor C1 is connected to ground. The IN- pin of the OP07 operational amplifier is connected to one end of resistor R2, and the other end of resistor R2 is connected to the output pin of the OP07 operational amplifier. The IN+ pin of the OP07 operational amplifier is grounded. The output pin of the OP07 operational amplifier is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the IN- pin of the OP07 operational amplifier. The output pin of the OP07 operational amplifier is connected to the analog input port of the PLC controller. The anode of the bidirectional TVS diode is connected to the IN+ pin and ground of the AD620 instrumentation amplifier. The cathode of the bidirectional TVS diode is connected to the IN- pin and ground of the AD620 instrumentation amplifier. The power input terminal of the PLC controller is connected to the power module. The ground terminal of the PLC controller is connected to ground. The PLC controller is connected to the expansion module through the backplane bus.

3. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 2, characterized in that, The drive module includes: a closed-loop stepper driver (1), a current sensor, a voltage comparator, a MOSFET Q1, a potentiometer, a switching diode, a high-speed optocoupler, a resistor R3, a resistor R4, and a resistor R5; The anode of the high-speed optocoupler is connected to one end of resistor R3, and the other end of resistor R3 is connected to the pulse output port of the PLC controller. The cathode of the high-speed optocoupler is grounded. The output port of the high-speed optocoupler is connected to the PUL+ port of the closed-loop stepper driver (1). The power port of the high-speed optocoupler is connected to the power module. The power port of the current sensor is connected to the power module. The grounding terminal of the current sensor is connected to ground. The output terminal of the current sensor is connected to one end of resistor R4. The other end of resistor R4 is connected to the non-inverting input terminal of the voltage comparator. The IP+ port of the current sensor is connected to the closed-loop stepper driver. The positive terminal of the power supply of the actuator (1) and the drain of the MOS transistor Q1 are connected. The IP-port of the current sensor is connected to the negative terminal of the power supply of the closed-loop stepper driver (1). The inverting input terminal of the voltage comparator is connected to the potentiometer. The output terminal of the voltage comparator is connected to one end of the switching diode. The other end of the switching diode is connected to the gate of the MOS transistor Q1. The power supply port of the voltage comparator is connected to the power module. The ground terminal of the voltage comparator is connected to ground. The gate of the MOS transistor Q1 is connected to one end of the resistor R5. The other end of the resistor R5 is connected to ground. The source of the MOS transistor Q1 is connected to ground.

4. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 3, characterized in that, The sensor module includes: a weighing sensor (5), an ADC analog-to-digital converter, a flow meter, a current loop receiver, a temperature sensor (4), and a resistor R6; The EXC+ pin of the load cell (5) is connected to the power supply module, the EXC- pin of the load cell (5) is connected to ground, the positive signal output terminal of the load cell (5) is connected to the positive analog signal input terminal of the ADC analog-to-digital converter and the non-inverting input terminal of the AD620 instrumentation amplifier, the negative signal output terminal of the load cell (5) is connected to the negative analog signal input terminal of the ADC analog-to-digital converter and the inverting input terminal of the AD620 instrumentation amplifier, the power input terminal of the ADC analog-to-digital converter is connected to the power supply module, the ground terminal of the ADC analog-to-digital converter is connected to ground, and the clock signal input terminal of the ADC analog-to-digital converter is connected to the PLC control module. The digital output port of the controller is connected, the data output terminal of the ADC analog-to-digital converter is connected to the digital input port of the PLC controller, the positive terminal of the flow meter is connected to the positive current input terminal of the current loop receiver, the negative terminal of the flow meter is connected to the negative current input terminal of the current loop receiver, the output terminal of the current loop receiver is connected to the analog input channel of the PLC controller, the data input terminal of the temperature sensor (4) is connected to the digital input port of the PLC controller, one end of the resistor R6 is connected, the other end of the resistor R6 is connected to the power supply port, the ground terminal of the temperature sensor (4) is connected to the ground, and the positive power supply terminal of the temperature sensor (4) is connected to the power supply port.

5. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 4, characterized in that, The human-computer interaction module includes: HMI touch screen, communication isolation chip, Darlington array, buzzer, LED light, and resistor R7; The VDD1 and VDD2 terminals of the communication isolation chip are connected to the power module; the GND1 and GND2 terminals of the communication isolation chip are connected to ground; the receive output terminal of the communication isolation chip is connected to the receive data pin of the HMI touchscreen; the transmit input terminal of the communication isolation chip is connected to the transmit data pin of the HMI touchscreen; the IN1 and IN2 pins of the Darlington array are connected to the digital output port of the PLC controller; the COM pin of the Darlington array is connected to the power port; the OUT1 pin of the Darlington array is connected to the positive terminal of the buzzer; the negative terminal of the buzzer is connected to ground; the OUT2 pin of the Darlington array is connected to one end of resistor R7; the other end of resistor R7 is connected to the anode of the LED; and the cathode of the LED is connected to ground.

6. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 5, characterized in that, Sequential continuous circuits include: RS flip-flops; The data input pin of the RS flip-flop is connected to the pulse output port of the PLC controller, the clock signal pin of RS is connected to the enable signal pin of the PLC controller, and the output pin of the RS flip-flop is connected to the PUL+ port of the closed-loop stepper driver (1).

7. The feed precision dosing control device based on PLC and closed-loop stepper motor according to claim 6, characterized in that, The power supply module includes: EMI filter, AC / DC converter, LM2596 step-down circuit, TPS7A4700 step-down circuit, resistor R8, fuse F1, ferrite bead, capacitor C3, capacitor C4, resistor R9, and resistor R10. The live wire terminal of the EMI filter is connected to the live wire of the 220V AC power supply, and the neutral wire terminal of the EMI filter is connected to the neutral wire of the 220V AC power supply. Resistor R8 is connected in series between the live wire terminal and the neutral wire terminal of the EMI filter. The protective grounding terminal of the EMI filter is connected to ground. The output terminal of the EMI filter is connected to the input terminal of the AC / DC converter. The output terminal of the AC / DC converter is connected to the power supply terminal of the PLC, the power supply input terminal of the closed-loop stepper driver (1), the COM pin of the Darlington array, one end of the ferrite bead, and one end of capacitor C3. The other end of capacitor C3 is connected to ground. The other end of the ferrite bead is connected to one end of fuse F1 and one end of capacitor C4. The other end is connected to ground, the other end of fuse F1 is connected to the input voltage pin of LM2596 step-down circuit, the output voltage pin of LM2596 step-down circuit is connected to the power supply pin of AD620 instrumentation amplifier, the power supply pin of OP07 operational amplifier, the power supply pin of low-pass filter, the power supply pin of high-speed optocoupler, and the input voltage pin of TPS7A4700 step-down circuit, the feedback pin of LM2596 step-down circuit is connected to one end of resistor R9, the other end of resistor R9 is connected to one end of resistor R10, the other end of resistor R10 is connected to ground, and the output voltage pin of TPS7A4700 step-down circuit is connected to the power supply pin of temperature sensor (4) and the power supply pin of ADC analog-to-digital converter.

Images