Automatic feedback regulation control system and control method for torque of permanent magnet synchronous motor

Abstract

The invention belongs to the technical field of electrical engineering, and particularly relates to a permanent magnet synchronous motor torque automatic feedback regulation control system and method, and the system comprises a control module, a communication module, an execution module and a sampling module. The control module compares and analyzes the value of the pressure borne by the material with the preset pressure value, the execution module is regulated and controlled through the communication module, the value of the pressure borne by the material is matched with the preset pressure value, and therefore self-feedback adjustment is achieved, and the refinement degree of the machined material can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical engineering, and in particular relates to a permanent magnet synchronous motor torque automatic feedback regulation control system and a control method. Background Art

[0002] With the development of material technology and market demand, material processing is no longer limited to processing and forming, but tends to be more refined to improve processing accuracy. The servo drive controls the motor to continuously output sinusoidal pressure waves, but there is often an error between theory and practice. During the operation of the motor, there is a situation where the output pressure value does not meet the actual working requirements, that is, the pressure on the material does not match the preset pressure. In order to solve the above problems, we propose a permanent magnet synchronous motor torque automatic feedback adjustment control system and control method. Summary of the invention

[0003] The object of the present invention is to provide a permanent magnet synchronous motor torque automatic feedback regulation control system, comprising an electrically connected execution module, a sampling module, a control module and a communication module, wherein the execution module is used for processing materials, the sampling module is used for collecting pressure data on the materials, the communication module is used for connecting the control module and the execution module, and the control module compares and analyzes the collected data with preset data and regulates the execution module.

[0004] Preferably, the execution module includes a servo driver and a servo motor; the control module adopts a single-chip microcomputer, the sampling module includes a pressure sensor and an analog-to-digital converter; and the communication module adopts a CAN communication module.

[0005] Preferably, the single-chip microcomputer adopts STM32F405, the chip pins PB12 and PB13 of the single-chip microcomputer are respectively connected to D and R of the CAN communication module, the analog-to-digital converter adopts AD7606, the chip pins PD0, 1, 8, 9, 10, 14, 15, PE7, 8, 9, 10, 11, 12, 13, 14, 15 of the single-chip microcomputer are connected to DB0-DB15 of AD7606, the OS0-OS2 pins of the digital-to-analog converter are connected to the PA0, PC2, PC3 pins of the single-chip microcomputer, and the sampling rate is controlled by the single-chip microcomputer.

[0006] Preferably, the V1-V8 pins of the digital-to-analog converter are connected to the pressure sensor to periodically sample the output data of the pressure sensor and convert the analog signal into a digital signal.

[0007] Preferably, the chip D and R pins of the CAN communication module are connected to the PB12 and PB13 pins of the single-chip microcomputer via a 10-ohm resistor, and the CAN H and CAN L pins are connected to the servo motor. By programming the single-chip microcomputer, the CPU sends information to the CAN. The CAN sends signals to the servo driver to control the output torque and frequency of the motor.

[0008] Preferably, it also includes a power supply module, the power supply module uses LM1117-3.3 as a low voltage dropout voltage regulator in the circuit, and a C22 tantalum capacitor is provided in the power supply circuit.

[0009] Preferably, the power supply circuit is configured to have three capacitors C24, C25 and C26 with different capacities connected in parallel to eliminate interference in different frequency bands in the system.

[0010] Another object of the present invention is to provide a permanent magnet synchronous motor torque automatic feedback adjustment control method, using the above automatic feedback adjustment control system, comprising the following steps: S1, processing materials, the control system sets the working parameters, sends signals to the servo driver via CAN communication to control the servo motor, and the servo motor drives the pressure device to process the materials, and the materials are subjected to the pressure of the execution equipment; S2, signal feedback, the pressure sensor detects the pressure of the material, the CPU controls AD7060 to regularly sample the output data of the pressure sensor, converts the analog signal into a digital signal, and the CPU regularly reads the digital signal converted by AD7606 and processes and analyzes it; S3. Feedback regulation. Based on the analysis results, the microcontroller calculates through the built-in program and encodes the data to be sent in binary format to send signal instructions to the servo driver in the form of CAN communication. The output current of the servo driver is changed to control the output torque of the permanent magnet synchronous motor. The frequency of the output waveform is controlled by changing the speed of sending the signal, thereby realizing feedback regulation so that the actual pressure on the material is the same as the preset pressure value.

[0011] The present invention has the following beneficial effects.

[0012] The present invention proposes a permanent magnet synchronous motor torque automatic feedback adjustment control system and control method. A self-feedback adjustment control system is constructed through an execution module, a sampling module, a control module and a communication module. The sampling module collects the pressure value output during the operation of the servo motor in real time. The control module compares and analyzes the actual pressure value with the preset pressure value, and then sends the adjustment request to the execution module through the communication module, thereby reducing the working error caused by mechanical mechanisms, hydraulic systems and the like during the processing, which is beneficial to improving the processing accuracy, ensuring the reliability of the processing, and facilitating more intuitive analysis of the processing data. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the flow chart of automatic feedback regulation control system.

[0014] Figure 2 This is the STM32F405 circuit diagram.

[0015] Figure 3 This is the AD7606 sampling circuit diagram.

[0016] Figure 4 It is a serial communication circuit diagram.

[0017] Figure 5 It is the CAN communication circuit diagram.

[0018] Figure 6 It is a step-down regulated power supply circuit diagram.

[0019] Figure 7 It is a circuit diagram of setting three light emitting diodes in the system.

[0020] Figure 8 This is the AD conversion reading timing diagram. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Reference Figure 1-Figure 8 The present invention collects the actual pressure data of the material and compares the actual pressure value with the preset pressure value. When the actual pressure value is different from the preset pressure value, the torque of the permanent magnet synchronous servo motor is adjusted to achieve automatic feedback adjustment so that the actual pressure value reaches the preset pressure value.

[0023] To achieve the above-mentioned purpose, the present invention proposes a permanent magnet synchronous motor torque automatic feedback adjustment control system, including an electrically connected execution module, a sampling module, a control module and a communication module, wherein the communication module is used to communicate with the control module and the execution module to transmit instructions, the sampling module is used to collect the pressure of the processed material, the control module reads the actual pressure value collected, and compares the actual pressure value with the preset pressure value, and controls the execution module to perform feedback adjustment through the comparison result, so that the actual pressure value of the material matches the preset pressure value.

[0024] The control module uses a single-chip microcomputer as the main control unit of the entire system. The single-chip microcomputer is specifically STM32F405, and the STM32F405 chip is used as the CPU of the system. STM32F405 regularly reads the data collected by the sampling module, sends instructions to the execution module through the communication module, and completes the closed-loop feedback adjustment.

[0025] The communication module adopts a CAN communication module, the sampling module samples analog signals and converts them into digital signals, the sampling module includes a pressure sensor and an analog-to-digital converter, wherein the analog-to-digital converter adopts AD7606, and the execution module includes a servo driver, a permanent magnet synchronous motor and a pressure device.

[0026] Reference Figure 2 , the CPU plays a role in controlling the start-up and frequency conversion of the permanent magnet synchronous servo motor in the entire automatic feedback control system; and reading the data for analysis at regular intervals. The chip pins PB12 and PB13 are connected to the D and R of the CAN communication module respectively. By programming the single-chip microcomputer, the STM32F405 sends signals to the servo driver through CAN to control its operation, thereby controlling the operation of the servo motor; the chip pins PD0, 1, 8, 9, 10, 14, 15, PE7, 8, 9, 10, 11, 12, 13, 14, 15 are connected to the DB0-DB15 of AD7606, and the pressure sensor output data sampled and converted into digital signals by AD7606 is read at regular intervals as a channel, and corresponding processing is performed.

[0027] In order to observe the working condition of CPU, three LEDs are added to the system to detect the working condition of CPU visually. Figure 7 When the CPU is working normally, different progress of its work corresponds to different LED lights. When different progress is completed, the LED lights are on. In the actual quality inspection device, the working status of the module can be analyzed more intuitively.

[0028] The execution module uses a servo driver and a servo motor. Specifically, it uses the ASDA-A2 series high-resolution open type servo driver. The driver uses precise feedback control and a digital signal processor (DSP) with high-speed computing capabilities to drive a three-phase permanent magnet synchronous AC servo motor (PMSM). The three-phase permanent magnet synchronous AC servo motor drives the pressure device to execute the processing of materials.

[0029] Reference Figure 3The sampling module samples analog signals and converts them into digital signals. The sampling module includes a pressure sensor and an analog-to-digital converter. The analog-to-digital converter uses AD7606, which is a 16-bit channel sampling analog-to-digital data acquisition system (DAS). To ensure the voltage stability of AD7606 during operation, C1, L1 and C2, L2 form a double filtering circuit. To ensure the stable sampling of analog signals, an AGND protection chip is added to the circuit to work normally. C4, C5, C6, and C22 filter out high-frequency signals to ensure system stability. The interface mode is controlled by controlling the high and low levels of the PAR / SER / BYTE SEL / and DB15 / BYTE SEL pins. If the output signals are all 0, it is a parallel interface mode; if the PAR input signal is 1 and the DB15 input signal is 0, it is a serial interface mode; if the output signals are all 1, it is a parallel byte interface mode.

[0030] The OS0-OS2 pins of AD7606 are connected to the PA0, PC2, and PC3 pins of the microcontroller. The microcontroller controls the sampling rate, and the PAR / SER / BYTE SEL pins select the sampling mode. The V1-V8 pins of AD7606 are connected to the pressure sensor, which samples the output data of the pressure sensor at regular intervals and converts the analog signal into a digital signal. The DB0-DB15 pins are connected to the microcontroller, and the CPU regularly reads the digital signal converted by AD7606 and processes and analyzes it.

[0031] In the interface mode of AD7606, when the parallel interface transmits data, each bit of the data is transmitted at the same time, and the transmission speed is fast, but the communication line is complex. When the transmission distance is long, the communication line is complex and the cost is high; when the serial interface transmits data, the data is transmitted one bit at a time in digital order, so the communication line is simple, and only one pair of transmission lines is needed to achieve two-way communication, which is low in cost and suitable for long-distance signal transmission, but the transmission speed is slow. In order to improve the working efficiency of the entire automatic feedback regulation control system, this automatic feedback regulation system uses the parallel interface mode.

[0032] Reference Figure 4 In order to realize the serial communication between the single-chip microcomputer and the host computer, the written program needs to be imported into the single-chip microcomputer through the host computer, so as to complete the control of each module by the single-chip microcomputer. This automatic feedback control system is based on the CH340 chip and designs the serial communication interface circuit. The CH340 chip is a USB bus adapter chip that can realize USB to serial port. It should be noted that if the working voltage of 3.3V is used, the working voltage of other circuits connected to the CH340 chip cannot exceed 3.3V. The function of this module is to enter the final instruction code into the initial device on the circuit board.

[0033] The TXD and RXD pins of CH340 are connected to the PA9 and 10 pins of the microcontroller, and the D+ and D- pins are connected to the D+ and D- of the USB interface. After writing the program on the computer, insert the data cable into the USB port, enter the program, and enter the program into the microcontroller through the adapter chip. C27 and C28 ensure that the voltage input to CH340 is stable, and R15-R19 protects the circuit to prevent excessive current in the circuit and damage to components. Ensure that CH340 can stably receive and transmit the downloaded program.

[0034] The automatic feedback regulation control system selects automatic downloading program. BOOTO is directly grounded through a resistor, and the system will automatically run when it is powered on, and the downloading program is simple.

[0035] In order to prevent the microcontroller from recording the wrong program, an asynchronous reset function is added to the circuit. The NRST pin of the CPU is an asynchronous reset pin. When NRST is in a low state, the MCU is in a reset state, formatting all internal registers and tens of KB of SRAM on the chip. When the NRST low level changes to a high level state, the PC pointer starts from address 0. The RTC registers and backup memory in the microcontroller will not be reset during reset because they are powered by a battery through a dedicated VBAT pin. The NRST in the STM32 has a Schmitt function. The chip is reset when the input voltage is about 1.9V.

[0036] Reference Figure 5 The communication module uses a CAN communication module based on the SN65HVD230 chip. The D and R pins of the chip are connected to the PB12 and PB13 pins of the STM32F405 microcontroller through a 10-ohm resistor, and the CAN H and CAN L pins are connected to the servo motor. By programming the microcontroller, the CPU sends information to the CAN. The servo driver is sent a signal through CAN to control the output torque and frequency of the servo motor. This system mainly uses the CAN extended frame. The main difference between the standard frame and the extended frame of CAN is the length. The extended frame is longer, so that more CAN nodes can be expanded to better support CAN work.

[0037] CAN is an asynchronous communication with only two signal lines, CAN_High and CAN_Low, which together form a set of differential signal lines and communicate in the form of differential signals. The CAN communication node consists of a CAN controller and a CAN receiver. The controller and the transceiver (level conversion) are connected by converting the CAN_Tx and CAN_Rx signal lines, and the transceiver is connected through the CAN_L and CAN_H signal lines. When the system CPU needs to send data, the CPU sends the data to be sent to the receiver in binary encoding through the CAN_Tx line, and then the transceiver converts the ordinary logic level into a differential signal and outputs it to the CAN network bus through the CAN_High and CAN_Low lines. When the transceiver receives the data on the bus to the CPU, it is in the opposite order and is finally output to the CPU through CAN_Rx.

[0038] In this automatic feedback adjustment system, STM32F405 is used as the main controller of CAN communication, and the servo drive is used as the receiver of CAN communication. The single-chip microcomputer sends signal instructions to the servo drive through CAN, and controls the output torque of the permanent magnet synchronous motor by changing the output current of the servo drive; the frequency of the output waveform is changed by changing the speed of sending signals. After the CPU reads the data sampled by AD7606 for analysis, if the output torque and frequency of the permanent magnet synchronous motor do not meet the preset values, the single-chip microcomputer still needs to send signals to the servo drive through CAN to make corresponding feedback adjustments.

[0039] Reference Figure 6 , in order to realize the normal power supply of the entire automatic feedback regulation control system and ensure the normal and stable working voltage of the single chip microcomputer. The power module uses LM1117-3.3 as the low voltage dropout voltage regulator in the circuit. LM1117 is a series of low voltage dropout voltage regulators that can realize automatic voltage regulation.

[0040] The system input voltage is 5V, while the voltage of the STM32F405 microcontroller during normal operation is 3.3V. To ensure the normal operation of the microcontroller, the 5V voltage needs to be converted to 3.3V. A tantalum capacitor C22 is added to the power supply circuit to prevent sudden power failure during system operation and voltage inversion. The capacitor has a filtering function. To eliminate interference in different frequency bands in the system, three capacitors with different capacities, C24, C25, and C26, are set in parallel in the power supply circuit to ensure a stable output of 3.3V voltage.

[0041] In order to observe whether the power module is working properly, a light-emitting diode is added to the circuit. If the circuit is working properly, it will output 3.3V voltage, the microcontroller can work normally and stably, and the diode will light up; if there is a fault in the circuit, the diode will not light up.

[0042] This automatic feedback regulation and control system uses the AD7606 analog-to-digital conversion chip. The chip CONVSTA and CONVSTB pins are connected to PB0 of the STM32F405 microcontroller. The AD conversion start is controlled by applying a low-level pulse signal to the pins. However, the two pins cannot apply low-level pulses at the same time, and there must be a certain time difference in between.

[0043] The chip pin BUSY is connected to PF13 of the microcontroller. When the output level is high, AD starts working and converts the collected pressure sensor output data into digital signals.

[0044] When all the collected analog signals are converted into digital signals, the BUSY pin of the chip automatically switches to a low level. When the microcontroller receives an interrupt signal from the BUSY pin, the AD conversion is completed. The microcontroller reads the converted data through the FSMC, and the program loops again. The present invention also provides a permanent magnet synchronous motor torque automatic feedback regulation control method, the control method adopts the permanent magnet synchronous motor torque automatic feedback regulation control system, and comprises the following steps: S1, processing materials, the control system sets the working parameters, sends signals to the servo driver to control the servo motor through CAN communication, and drives the pressure device to process the materials through the servo motor. The materials are subjected to the pressure of the pressure device; S2, signal feedback, the pressure sensor detects the pressure of the material, the CPU controls AD7060 to regularly sample the output data of the pressure sensor, converts the analog signal into a digital signal, and the CPU regularly reads the digital signal converted by AD7606 and processes and analyzes it; S3. Feedback regulation. Based on the analysis results, the microcontroller calculates through the built-in program and encodes the data to be sent in binary format to send signal instructions to the servo driver in the form of CAN communication. The output current of the servo driver is changed to control the output torque of the permanent magnet synchronous motor. The frequency of the output waveform is controlled by changing the speed of sending the signal, thereby realizing feedback regulation so that the actual pressure on the material is the same as the preset pressure value.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A permanent magnet synchronous motor torque automatic feedback regulation control system, characterized in that: It includes an electrically connected execution module, a sampling module, a control module and a communication module. The execution module is used to process materials, the sampling module is used to collect pressure data on the materials, the communication module is used to connect the control module and the execution module, and the control module compares and analyzes the collected data with the preset data and regulates the execution module.

2. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 1, characterized in that: The execution module includes a servo driver and a servo motor; the control module adopts a single-chip microcomputer; the sampling module includes a pressure sensor and an analog-to-digital converter; and the communication module adopts a CAN communication module.

3. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 2, characterized in that: The single-chip microcomputer adopts STM32F405, and the chip pins PB12 and PB13 of the single-chip microcomputer are respectively connected to D and R of the CAN communication module. The analog-to-digital converter adopts AD7606, and the chip pins PD0, 1, 8, 9, 10, 14, 15 and PE7, 8, 9, 10, 11, 12, 13, 14, 15 of the single-chip microcomputer are connected to DB0-DB15 of AD7606, and the OS0-OS2 pins of the digital-to-analog converter are connected to the PA0, PC2, PC3 pins of the single-chip microcomputer, and the sampling rate is controlled by the single-chip microcomputer.

4. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 3, characterized in that: The V1-V8 pins of the digital-to-analog converter are connected to the pressure sensor to regularly sample the output data of the pressure sensor and convert the analog signal into a digital signal.

5. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 3, characterized in that: The chip D and R pins of the CAN communication module are connected to the PB12 and PB13 pins of the single-chip microcomputer via a 10-ohm resistor, and the CAN H and CAN L pins are connected to the servo motor.

6. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 3, characterized in that: It also includes a power supply module, which uses LM1117-3.3 as a low-voltage dropout voltage regulator in the circuit, and a C22 tantalum capacitor is arranged in the power supply circuit.

7. The permanent magnet synchronous motor torque automatic feedback regulation control system according to claim 6, characterized in that: The power supply circuit is configured to connect three capacitors C24, C25 and C26 with different capacities in parallel to eliminate interference in different frequency bands in the system.

8. A method for automatic feedback regulation and control of torque of a permanent magnet synchronous motor, using the automatic feedback regulation and control system according to any one of claims 3 to 7, characterized in that: The following steps are involved: S1, processing materials, the control system sets the working parameters, sends signals to the servo driver via CAN communication to control the servo motor, and the servo motor drives the pressure device to process the materials, and the materials are subjected to the pressure of the execution equipment; S2, signal feedback, the pressure sensor detects the pressure of the material, the CPU controls AD7060 to regularly sample the output data of the pressure sensor, converts the analog signal into a digital signal, and the CPU regularly reads the digital signal converted by AD7606 and processes and analyzes it; S3. Feedback regulation. Based on the analysis results, the microcontroller calculates through the built-in program and encodes the data to be sent in binary format to send signal instructions to the servo driver in the form of CAN communication. The output current of the servo driver is changed to control the output torque of the permanent magnet synchronous motor. The frequency of the output waveform is controlled by changing the speed of sending the signal, thereby realizing feedback regulation so that the actual pressure on the material is the same as the preset pressure value.

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