A multi-module cooperative high-reliability stepping motor valve driving circuit

Abstract

The utility model discloses a kind of high reliability stepper motor valve drive circuit of multi-module cooperation, including power supply module, main control module, stepper motor control module, CAN communication module, power-off save module, valve position feedback module and locked-rotor detection module;Power supply module is used for power supply;Main control module is connected with stepper motor control module, for output control signal;CAN communication module is connected with main control module, for realizing the two-way communication between main control module and host computer;Power-off save module is connected with main control module, for storing the control signal that main control module sends to stepper motor control module;Valve position feedback module is connected with valve and main control module, for the signal feedback of valve opening degree to main control module;Locked-rotor detection module is connected with stepper motor control module and main control module, for the two-phase current size of stepper motor in real time feedback main control module. Utilize the utility model, can improve the reliability and control accuracy of valve control.

Description

Technical Field

[0001] This utility model relates to the field of valve control technology, and in particular to a highly reliable stepper motor valve drive circuit with multi-module collaboration. Background Technology

[0002] Valves, as key actuators in modern industrial processes, play a vital role in many industrial fields such as petrochemicals, water treatment, and papermaking. Their core function lies in the precise regulation of the flow rate, pressure, and concentration of fluid media, thereby ensuring the stability of the production process and the consistency of product quality. Especially in applications such as headbox control in the papermaking industry, process regulation in petrochemicals, and smart water management, the control performance of valves directly affects the operating efficiency and energy consumption level of the entire system.

[0003] In industrial applications, 4-20mA analog signals are commonly used to control valves. However, their accuracy is easily affected by factors such as current source stability, line impedance, and electromagnetic interference, which may lead to signal attenuation and adjustment deviations. On the other hand, valves in many industrial applications require small amplitude, high resolution, and fast response adjustment performance.

[0004] Stepper motors, as actuators that directly convert digital pulse signals into angular displacement, offer advantages such as high control precision, accurate positioning, low operating noise, and fast response speed, enabling digital and precise control of valve opening. The closed-loop characteristics of stepper motors also effectively avoid interference problems in analog signal transmission, improving the system's anti-interference capability and reliability. Therefore, they are particularly suitable for valve control scenarios with high precision and high dynamic requirements.

[0005] Current valve control circuits mainly have the following problems: (1) The power supply used in the valve control circuit is often not isolated, which can easily cause problems due to the complex environment of the industrial site; (2) The valve control circuit lacks a real-time monitoring and feedback mechanism for abnormal states such as stepper motor stall, and cannot provide timely and effective protection when stall occurs; (3) Stepper motors are prone to losing steps after running for a long time. Existing valve control circuits do not have a simple and effective means to eliminate this cumulative error, which cannot meet the needs of modern industry for high precision, high reliability and low delay control. Utility Model Content

[0006] This invention provides a highly reliable stepper motor valve drive circuit with multi-module collaboration, which can improve the reliability and accuracy of valve control.

[0007] A highly reliable stepper motor valve drive circuit with multi-module collaboration includes a power supply module, a main control module, a stepper motor control module, a CAN communication module, a power failure preservation module, a valve position feedback module, and a stall detection module. The power supply module is connected to the other modules and is used to supply power. The main control module is connected to the stepper motor control module and is used to output control signals to the stepper motor control module to control the stepper motor to drive the valve to move. The CAN communication module is connected to the main control module and is used to realize bidirectional communication between the main control module and the host computer. The power failure preservation module is connected to the main control module and is used to store the control signals sent by the main control module to the stepper motor control module; The valve position feedback module is connected to the valve and the main control module, and is used to detect the valve opening degree and feed back the valve opening degree signal to the main control module. The stall detection module is connected to the stepper motor control module and the main control module, and is used to provide real-time feedback to the main control module on the magnitude of the two-phase current of the stepper motor.

[0008] Furthermore, the power supply module includes a 24V to 5V circuit, a 5V to 3.3V circuit, and a 5V to 2.5V circuit; The 24V to 5V circuit powers the stepper motor control module and the stall detection module; the 5V to 3.3V circuit powers the main control module, the CAN communication module, and the power-off data retention module; and the 5V to 2.5V circuit powers the valve position feedback circuit.

[0009] The power supply module includes two two-stage 24V to 5V circuits. One 24V to 5V circuit, composed of a power supply chip and external resistors, capacitors, diodes, and inductors, is dedicated to powering the stepper motor driver chip U5 and the stall detection module in the stepper motor control module. The other 24V to 5V circuit, implemented using an isolated power supply module and external resistors and capacitors, provides input to the subsequent 5V to 3.3V power supply chip and 5V to 2.5V reference chip. The 5V to 3.3V circuit, through the power supply chip and corresponding external circuits, powers the MCU control chip U1 and other related circuits in the main control module; the 5V to 2.5V circuit, through the power reference chip and corresponding external circuits, powers the valve position feedback module. Furthermore, the isolated power supply module isolates the power supply of the stepper motor control module from the power supply of the main control module, forming independent analog ground, digital ground, and power supply, effectively reducing crosstalk between analog and digital signals and improving control accuracy.

[0010] Furthermore, the main control module includes an MCU control chip U1, a reset circuit, a crystal oscillator circuit, and a download and debugging circuit; The reset circuit is used to power on and initialize the MCU control chip U1. The crystal oscillator circuit is used to provide the clock frequency required for the MCU control chip U1 to operate. The download and debugging circuit is used to download and debug the program to the MCU control chip U1. The MCU control chip U1 is connected to other modules through its pins.

[0011] The main control module is based on the MCU control chip U1 and includes a crystal oscillator circuit, a reset circuit, a download and debugging circuit, and necessary external capacitors and resistors. This circuit is responsible for coordinating control and is connected to the stepper motor control module, CAN communication module, stall detection module, power-off data retention module, and valve position feedback module to control signal input and output.

[0012] Furthermore, the stepper motor control module includes a stepper motor control chip U5, a digital isolation chip U7, a digital isolation chip U8, and a programmable digital potentiometer U6; The digital isolation chip U7 is used to isolate the control signals from the main control module to the stepper motor control chip; the control signals mainly include motor enable signal, direction control signal, and PWM step signal. The digital isolation chip U8 is used to isolate the SPI signal between the programmable digital potentiometer U6 and the main control module. The programmable digital potentiometer U6 is connected to the main control module and the stepper motor control chip U5. It is used to communicate with the main control module and adjust the current output by the stepper motor control chip U5 when driving the stepper motor.

[0013] Furthermore, the CAN communication module includes a DIP switch S1; The DIP switch S1 is connected to the control module and is used to set the node address parameters to achieve CAN bus communication of 256 nodes.

[0014] Furthermore, the power-off data preservation module includes a storage chip U10; The storage chip U10 is connected to the control module and is used to store the control signals sent by the main control module to the stepper motor control module. When the system restarts, the stored key parameters (control signals) can be saved in the storage chip U10 without needing to be reset.

[0015] Furthermore, the valve position feedback module consists of peripheral components such as resistors, capacitors, and diodes. After the external valve opening signal is conditioned by the resistors, capacitors, and diodes, the ADC sampling pin of the MCU control chip U1 collects the valve opening signal to determine the current valve position.

[0016] Furthermore, the stall detection module includes an ADC sampling chip U11 and a dual operational amplifier chip U12; The dual operational amplifier chip U12 is connected to the stepper motor control module and is used to receive the voltage signal obtained by converting the two-phase current of the stepper motor and amplify and filter it. The input terminal of the ADC sampling chip U11 is connected to the dual operational amplifier chip U12, and the output terminal is connected to the main control module through the SPI interface. It is used to provide real-time feedback to the main control module on the magnitude of the two-phase current of the stepper motor based on the voltage signal output by the dual operational amplifier chip U12.

[0017] In the stall detection module, multiple high-precision, low-temperature-drift sampling resistors are connected in parallel, reducing the power load of individual resistors and improving sampling accuracy and thermal stability. When the stepper motor reaches the upper or lower limit of the valve, the motor stalls. The MCU control chip U1 saves the upper and lower limit valve position values ​​at this time to the storage chip U10, and periodically performs self-calibration of the upper and lower limit valve positions through the stall point, which can eliminate long-term cumulative errors caused by stepper motor step loss. If the stall is detected not due to the stepper motor reaching the upper or lower limit of the valve, it is determined to be an abnormal stall, and the valve circuit controls the motor to stop rotating to check the abnormal point.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention incorporates a valve position feedback module and a stall detection module. By combining closed-loop control of the circuit with stall detection, it not only achieves precise valve position control and real-time protection, but also periodically calibrates the upper and lower limits of the valve position through stall points, further eliminating the cumulative error of the stepper motor and improving control accuracy.

[0019] This invention incorporates a CAN communication module and a power-off parameter saving module. By combining CAN bus communication with power-off parameter saving functions, it enables data interaction between the host computer and the control circuit. The parameters set by the host computer can be directly saved in the storage chip without being lost, further enhancing the reliability of valve control. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an overall structural diagram of a multi-module collaborative high-reliability stepper motor valve drive circuit according to this utility model.

[0022] Figure 2 This is a circuit diagram of the power supply module in an embodiment of this utility model.

[0023] Figure 3 This is a circuit diagram of the main control module in an embodiment of this utility model.

[0024] Figure 4 This is a circuit diagram of the stepper motor control module in an embodiment of the present invention.

[0025] Figure 5 This is a circuit diagram of the CAN communication module in an embodiment of this utility model.

[0026] Figure 6 This is a circuit diagram of the power-off data preservation module in an embodiment of this utility model.

[0027] Figure 7 This is a circuit diagram of the valve position feedback module in an embodiment of this utility model.

[0028] Figure 8 This is a circuit diagram of the stall detection module in an embodiment of the present invention. 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] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0031] like Figure 1 As shown, a highly reliable stepper motor valve drive circuit with multi-module collaboration includes a power supply module, a main control module, a stepper motor control module, a CAN communication module, a power failure preservation module, a valve position feedback module, and a stall detection module.

[0032] In the power supply module, the 24V to 5VA circuit powers the stepper motor control module and the stall detection module; the 5V to 3.3V circuit powers the main control module, the CAN communication module, and the power-off data storage module; and the 5V to 2.5V circuit powers the valve position feedback circuit. The main control module is connected to the stepper motor control module, driving the valve through output control signals. The CAN communication module connects to the main control module, enabling bidirectional communication with the host computer, receiving commands from the host computer and uploading status data. The power-off data storage module connects to the main control module and stores key valve information sent by the main control module. The valve position feedback module connects to the main control module and feeds back valve signals. The stall detection module also connects to the main control module, providing real-time feedback on the motor phase current.

[0033] like Figure 2 As shown, the power supply module includes a 24V to 5VD circuit, a 5VD to 3.3V circuit, a 24V to 5VA circuit, and a 5VA to 2.5V circuit. An external +24V_IN voltage is input via connector J1, and after passing through fuse F1, a +24V power supply is generated, which is then sent to the DC-DC chip U2 and the isolated power supply module U3. The DC-DC chip U2 converts the 24V to 5VA, while the isolated power supply module U3 outputs the isolated 5VD power supply. The isolated power supply module U3 divides the ground of the stepper motor control circuit and the main control circuit into analog ground AGND and digital ground GND, effectively reducing crosstalk between analog and digital signals. The 5VD power supply is converted to 3.3V via LDO linear regulator U4 as the main power supply for the digital circuit. The 2.5V power supply is generated by the reference source chip U5 and is dedicated to powering the valve position feedback module; its high precision and low ripple characteristics help improve the accuracy of the valve position feedback voltage.

[0034] like Figure 3 As shown, the main control module is centered around the MCU control chip U1 and includes a crystal oscillator circuit, a reset circuit, a download and debugging circuit, as well as external resistors and capacitors. The reset circuit initializes the MCU control chip U1 by pulling the RST pin low. The crystal oscillator circuit provides the clock frequency required for the MCU control chip U1 to operate. The download and debugging circuit is used to download and debug programs to the MCU control chip U1. The MCU control chip controls other modules in the circuit through its pin outputs.

[0035] like Figure 4As shown, the stepper motor control module mainly consists of a stepper motor control chip U5, a digital isolation chip U7, a digital isolation chip U8, a programmable digital potentiometer U6, and external resistors and capacitors. The DIR, ENABLE, and STEP signals isolated by the digital isolation chip U7 are the core signals controlling the stepper motor's movement, controlling the stepper motor's direction, enable, and step angle, respectively. When the ENABLE and DIR pins of the MCU control chip U1 output a high level, the STEP pin outputs a square wave signal of a fixed frequency, enabling the stepper motor to maintain forward rotation at a certain speed. The digital isolation chip U8 isolates the SPI signal used for communication with the programmable digital potentiometer U6. The MCU control chip U1 can set the resistance value of the programmable digital potentiometer U6 within its nominal resistance range via SPI communication.

[0036] The resistance values ​​corresponding to potentiometer pins 5 and 6 are as follows. , D represents the maximum adjustable resistance value of the digital potentiometer. D is the data set via SPI communication, and its range is 0-256. After connecting pin 5 of the potentiometer to AGND and pin 7 to 5VA, pin 6 will output the voltage. This voltage can adjust the current output by the stepper motor control chip U5 when driving the motor. The magnitude of this current is... The current value output by the stepper control chip U5 can be adjusted using a digital potentiometer, making it compatible with various models of stepper motors.

[0037] The CR pin of the stepper motor control chip U5 is connected in series with resistor R25 and capacitor C18 to AGND to set the chopping frequency of the stepper motor chip U5. This frequency determines the adjustment accuracy of the motor current and the stability of the motor operation.

[0038] Fine control of the stepper motor can be achieved by adjusting the MS1 and MS2 pins. Soldering resistors R22 and R26, with MS1 and MS2 pins at low level, enables the motor to step in full steps. Soldering resistors R19 and R26, with MS1 pin at high level and MS2 pin at low level, enables the motor to step in half steps. Soldering resistors R26 and R17, with MS1 pin at low level and MS2 pin at high level, enables the motor to step in 1 / 8 steps. Soldering resistors R17 and R19, with MS1 and MS2 pins at high level, enables the motor to step in 1 / 16 steps. In this mode, the motor movement is extremely smooth, noise is minimal, and precise positioning can be achieved.

[0039] Pins 1A, 1B and 2A, 2B are the output control coil pins of the two-phase stepper motor. They are connected to an external stepper motor via connector J5 to control the motor's movement.

[0040] like Figure 5As shown, the CAN communication module mainly consists of a CAN communication isolation module U9, a DIP switch S1, and external resistors. By setting the eight different states of the DIP switch S1, 256 binary CAN node ID addresses can be formed. By sequentially connecting the CANH and CANL pins on the J6 interface of each valve control circuit, a master-slave control architecture can be realized, with the host computer as the master and multiple valve control boards as slaves. This forms a CAN bus communication network, allowing one host computer to control the movement of multiple valves and provide feedback on their valve position information, thus achieving centralized and coordinated control of multiple valves.

[0041] like Figure 6 As shown, the power-off data retention module includes a storage chip U10 and external resistors. The storage chip U10 communicates with the MCU control chip U1 via the IIC protocol to store key valve parameters. After a system power failure and restart, the MCU control chip U1 can directly read the stored data from the storage chip U10 without reconfiguring parameters, ensuring the continuity and reliability of the control state.

[0042] like Figure 7 As shown, the valve position feedback module is used to detect the valve opening in real time. It is powered by a 2.5V reference voltage to reduce fluctuations in the valve position signal voltage and improve sampling accuracy. The host computer sends an action command via CAN bus communication to control the stepper motor to rotate the valve through a specified angle. At this point, the valve position signal AD_IN, after being RC filtered, is input to the ADC sampling pin built into the MCU control chip U1. The valve position voltage signal is converted into valve opening data and transmitted to the host computer via CAN bus communication to display the current valve position.

[0043] like Figure 8As shown, the stall detection module includes an ADC sampling chip U11, a dual operational amplifier chip U12, a digital isolation chip U13, and external resistors and capacitors. This circuit detects stall by sampling the current in two phases of the stepper motor's coils. The ISENSE1 and ISENSE2 pins of the stepper motor control chip U5 correspond to the two-phase current signals, respectively. A high-precision sampling resistor group, R28 and R46 in parallel, and R47 and R48 in parallel, converts the coil current into a voltage signal. This signal is amplified by a non-inverting proportional amplifier circuit composed of the dual operational amplifier chip U12, then filtered by RC, and sent to the ADC sampling chip U11 for analog-to-digital conversion. The ADC sampling chip U11 communicates with the MCU control chip U1 via an SPI interface. When the valve control circuit is powered on for the first time, the system controls the stepper motor to run to the lower valve position limit. At this time, the ISENSE1 and ISENSE2 currents increase sharply, and the MCU control chip U1 records the current valve position value and stores it as the lower valve position. Subsequently, the system controls the motor to reverse to the upper valve position. When a sharp increase in current is detected again, the current valve position value is recorded as the upper valve position. By periodically performing self-calibration of the upper and lower valve positions at this stall point, the cumulative errors caused by stepper motor loss of steps and other reasons can be eliminated. When stall occurs, the MCU control chip U1 can distinguish between normal operation and abnormal stall by comparing the current stall point valve position with the stored upper and lower limit valve positions. If the current feedback valve position value is not at the upper or lower limit position, it is determined to be an abnormal situation, and the valve circuit controls the motor to stop rotating, stopping the machine to check the cause of the abnormal stall.

[0044] The embodiments described above provide a detailed explanation of the technical solution and beneficial effects of this utility model. It should be understood that the above descriptions are only specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, additions, and equivalent substitutions made within the scope of the principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-reliability stepper motor valve drive circuit with multi-module collaboration, characterized in that, It includes a power supply module, a main control module, a stepper motor control module, a CAN communication module, a power failure data storage module, a valve position feedback module, and a stall detection module; The power supply module is connected to the other modules and is used to supply power. The main control module is connected to the stepper motor control module and is used to output control signals to the stepper motor control module to control the stepper motor to drive the valve to move. The CAN communication module is connected to the main control module and is used to realize bidirectional communication between the main control module and the host computer. The power failure preservation module is connected to the main control module and is used to store the control signals sent by the main control module to the stepper motor control module; The valve position feedback module is connected to the valve and the main control module, and is used to detect the valve opening degree and feed back the valve opening degree signal to the main control module. The stall detection module is connected to the stepper motor control module and the main control module, and is used to provide real-time feedback to the main control module on the magnitude of the two-phase current of the stepper motor.

2. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The power supply module includes a 24V to 5V circuit, a 5V to 3.3V circuit, and a 5V to 2.5V circuit; The 24V to 5V circuit powers the stepper motor control module and the stall detection module; the 5V to 3.3V circuit powers the main control module, the CAN communication module, and the power-off data retention module; and the 5V to 2.5V circuit powers the valve position feedback circuit.

3. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The main control module includes an MCU control chip U1, a reset circuit, a crystal oscillator circuit, and a download and debugging circuit; The reset circuit is used to power on and initialize the MCU control chip U1. The crystal oscillator circuit is used to provide the clock frequency required for the MCU control chip U1 to operate. The download and debugging circuit is used to download and debug the program to the MCU control chip U1. The MCU control chip U1 is connected to other modules through its pins.

4. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The stepper motor control module includes a stepper motor control chip U5, a digital isolation chip U7, a digital isolation chip U8, and a programmable digital potentiometer U6; The digital isolation chip U7 is used to isolate the control signals from the main control module to the stepper motor control chip; The digital isolation chip U8 is used to isolate the SPI signal between the programmable digital potentiometer U6 and the main control module. The programmable digital potentiometer U6 is connected to the main control module and the stepper motor control chip U5. It is used to communicate with the main control module and adjust the current output by the stepper motor control chip U5 when driving the stepper motor.

5. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The CAN communication module includes a DIP switch S1; The DIP switch S1 is connected to the control module and is used to set the node address parameters to achieve CAN bus communication of 256 nodes.

6. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The power failure preservation module includes a storage chip U10; The storage chip U10 is connected to the control module and is used to store the control signals sent by the main control module to the stepper motor control module.

7. The high-reliability stepper motor valve drive circuit with multi-module collaboration according to claim 1, characterized in that, The stall detection module includes an ADC sampling chip U11 and a dual operational amplifier chip U12; The dual operational amplifier chip U12 is connected to the stepper motor control module and is used to receive the voltage signal obtained by converting the two-phase current of the stepper motor and amplify and filter it. The input terminal of the ADC sampling chip U11 is connected to the dual operational amplifier chip U12, and the output terminal is connected to the main control module through the SPI interface. It is used to provide real-time feedback to the main control module on the magnitude of the two-phase current of the stepper motor based on the voltage signal output by the dual operational amplifier chip U12.

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