A control method for AC magnetic levitation and an AC magnetic levitation experimental device

Abstract

The present invention relates to a teaching experimental device and discloses a control method for AC magnetic levitation and an AC magnetic levitation experimental device. The AC magnetic levitation experimental device includes a magnetic levitation controller and a magnetic levitation experimental platform. The magnetic levitation controller sends a control signal to a magnetic levitation control console, and the magnetic levitation control console feeds back a signal to the magnetic levitation controller. The invention is characterized in that the control signal sent by the magnetic levitation controller is a magnetic levitation control signal obtained by the control method for AC magnetic levitation. The AC magnetic levitation experimental device designed by the present invention is conducive to highly closed-loop control of magnetic levitation. The present invention determines the stability of the AC magnetic levitation control signal by using weight factors, while also improving the ability to regulate and control different states.

Description

Technical Field

[0001] The invention relates to a teaching experimental device, in particular to an AC magnetic levitation control method and an AC magnetic levitation experimental device. Background Art

[0002] Magnetic levitation is based on the principles of electromagnetic induction and Lenz's law. An alternating current passing through a coil generates an alternating magnetic field. This field induces a current in a closed conductor. The direction of the induced current always causes its own magnetic field to obstruct the change in the original magnetic field. Therefore, the magnetic field generated by the coil and the magnetic field of the induced current repel each other. If the repulsive force exceeds gravity, magnetic levitation can be observed.

[0003] Magnetic levitation technology is a high-tech that integrates electromagnetism, electromagnetic induction technology, fixed-axis rotation, and dynamics. With the development of electronic technology, control engineering, electromagnetic theory, new electromagnetic materials, and rotor dynamics, magnetic levitation technology has made great progress. Electromagnetic levitation technology has broad application prospects in the preparation and purification of high-melting-point, high-activity, and highly radioactive materials.

[0004] As a typical nonlinear hysteresis system, the magnetic levitation control system is not ideal for traditional PID control when an accurate control model cannot be obtained. When using type I fuzzy PID, definition differences are inevitable based on the properties of type I fuzzy membership functions, and there is a certain static error in the output.

[0005] For example, the patent title is "A Magnetic Levitation Experimental Apparatus," and the patent application number is CN201120115313.3. The apparatus consists of a main unit, an upper controllable magnetic field coil, a gyro rotor, and a gasket plate. The main unit is equipped with a four-digit ammeter, four digital control buttons, and a switch. The main unit also contains a high-current constant current source and a single-chip microcomputer control and amplification circuit. Through experiments on magnetic levitation and its relationship to current and magnetic fields, the apparatus enables students to better understand and master the laws and characteristics of magnetic levitation and magnetic fields.

[0006] The existing magnetic levitation experimental device has poor control stability for the magnetic levitation controller and is easily disturbed by other environments. Summary of the Invention

[0007] Aiming at the shortcomings of the prior art magnetic levitation experimental device, which has poor control stability of the magnetic levitation controller and is easily disturbed by other environments, the present invention provides an AC magnetic levitation control method and an AC magnetic levitation experimental device.

[0008] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0009] A control method for AC magnetic levitation, the method comprising:

[0010] S1: Determination of control factors, determine the factors that affect the control of AC magnetic levitation, and summarize and number them;

[0011] S2: Determine the control object comments, classify the control objects of the AC magnetic levitation, and determine the object comment set;

[0012] S3: Determination of weight factors. In S1 and S2, different control factors will lead to different effects, thus determining the control weight factors of AC magnetic levitation;

[0013] S4: Determine the control signal of the AC magnetic levitation according to the weight factor.

[0014] Preferably, the weight factors are determined by obtaining the weight factors according to a weighted average state training algorithm;

[0015] Initialize weight factors and memory bank;

[0016] Explore through random strategies to fill the memory bank;

[0017] Determine the action to be performed through a greedy strategy;

[0018] Execute an action to obtain a new weight factor, and store the new weight factor in a memory bank;

[0019] The weight factors are determined based on the weight factors in the memory bank.

[0020] In order to solve the above technical problems, the present application also provides an AC magnetic levitation experimental device, including a magnetic levitation controller and a magnetic levitation experimental platform. The magnetic levitation controller sends a control signal to the magnetic levitation control console, and the magnetic levitation control console feeds back a signal to the magnetic levitation controller; it is characterized in that the control signal sent by the magnetic levitation controller is a magnetic levitation control signal obtained by the AC magnetic levitation control method.

[0021] Preferably, the magnetic levitation console is provided with a magnetic levitation coil, which is connected to a sliding rheostat; the magnetic levitation controller includes a single chip microcomputer and an AC voltage regulation module;

[0022] When the magnetic levitation coil is suspended, the sliding rheostat receives the height signal of the magnetic levitation coil and transmits the height signal of the magnetic levitation coil to the sliding rheostat, which transmits the signal to the single chip microcomputer, which processes the signal and transmits the processed signal to the AC voltage regulation module;

[0023] The AC voltage regulating module is connected to the sliding rheostat, and the AC voltage regulating module outputs a pulse signal to control the sliding of the sliding rheostat.

[0024] Preferably, the magnetic levitation controller includes a chassis, a front panel, a rear panel and a fixed base plate; the fixed base plate is located at the bottom of the chassis, and the front panel and the rear panel are relatively located on the chassis.

[0025] Preferably, a power switch and a training board are provided on the front panel; a national standard power socket, a voltage regulating output socket and a power input interface are provided on the rear panel.

[0026] Preferably, a core board and a serial port AD conversion circuit board are provided in the chassis.

[0027] Preferably, a human-computer interaction interface unit is provided on the training board.

[0028] The present invention has significant technical effects due to the adoption of the above technical solutions:

[0029] The present invention determines the control signal of the AC magnetic levitation through weight factors, which has good stability and improves the regulation and control capabilities of different states.

[0030] The AC magnetic levitation experimental device designed by the present invention is conducive to the highly closed-loop control of magnetic levitation, has good stability, and is not easily disturbed by other environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a system diagram of the magnetic levitation experimental device of the present invention.

[0032] Figure 2 It is a control flow chart of the present invention.

[0033] Figure 3 It is a flow chart of determining weight factors of the present invention.

[0034] Figure 4 It is a single chip microcomputer control circuit diagram of the present invention.

[0035] Figure 5 It is a display circuit diagram of the present invention.

[0036] Figure 6 This is a circuit diagram of the AC voltage regulation module of the present invention.

[0037] Figure 7 It is a serial port AD conversion circuit diagram of the present invention;

[0038] Figure 8 is a schematic diagram of the front panel of the present invention;

[0039] Figure 9 It is a schematic diagram of the rear panel of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] A control method for AC magnetic levitation, the method comprising:

[0043] S1: Determination of control factors, determine the factors that affect the control of AC magnetic levitation, and summarize and number them;

[0044] S2: Determine the control object comments, classify the control objects of the AC magnetic levitation, and determine the object comment set;

[0045] S3: Determination of weight factors. In S1 and S2, different control factors will lead to different effects, thus determining the control weight factors of AC magnetic levitation;

[0046] S4: Determine the control signal of the AC magnetic levitation according to the weight factor.

[0047] The weight factors are determined by obtaining the weight factors based on the weighted average state training algorithm;

[0048] Initialize weight factors and memory bank;

[0049] Explore through random strategies to fill the memory bank;

[0050] Determine the action to be performed through a greedy strategy;

[0051] Execute an action to obtain a new weight factor, and store the new weight factor in a memory bank;

[0052] The weight factors are determined based on the weight factors in the memory bank.

[0053] Example 2

[0054] Based on Example 1, this embodiment provides an AC magnetic levitation experimental device, which includes a magnetic levitation controller and a magnetic levitation experimental platform. The magnetic levitation controller sends a control signal to the magnetic levitation console, and the magnetic levitation console feeds back a signal to the magnetic levitation controller; the control signal sent by the magnetic levitation controller is the magnetic levitation control signal obtained by the AC magnetic levitation control method of Example 1.

[0055] The magnetic levitation console is provided with a magnetic levitation coil, which is connected to a sliding rheostat; the magnetic levitation controller includes a single chip microcomputer and an AC voltage regulation module;

[0056] When the magnetic levitation coil is suspended, the sliding rheostat receives the height signal of the magnetic levitation coil and transmits the height signal of the magnetic levitation coil to the sliding rheostat, which transmits the signal to the single chip microcomputer, which processes the signal and transmits the processed signal to the AC voltage regulation module;

[0057] The AC voltage regulating module is connected to the sliding rheostat, and the AC voltage regulating module outputs a pulse signal to control the sliding of the sliding rheostat.

[0058] The magnetic levitation controller includes a chassis, a front panel, a rear panel and a fixed base plate; the fixed base plate is located at the bottom of the chassis, and the front panel and the rear panel are relatively located on the chassis.

[0059] The front panel is equipped with a power switch and a training board; the rear panel is equipped with a national standard power socket, a voltage regulating output socket and a power input interface.

[0060] The chassis is equipped with a core board and a serial port AD conversion circuit board.

[0061] The training board is equipped with a human-computer interaction interface unit.

[0062] Example 3

[0063] Based on the above embodiment, this embodiment provides a control method for AC magnetic levitation.

[0064] Determine the control factors of the magnetic levitation controller, which include the mass of the coil, constant, gravity acceleration, voltage across the coil, coil resistance, coil inductance, and operating point;

[0065] To determine the weight factors, we first initialize the object comment set, explore using a random strategy, and store the exploration results in the object comment set. We then determine the number of steps in a single round. If the number of steps in a single round is less than 800, we increment the number of rounds by 1. We then select an action using a greedy strategy, execute the action, and obtain the state of the magnetic levitation coil.

[0066] The controller uses the offset of the magnetic levitation coil from the operating point, the speed, and the control current as state inputs. The voltage is divided into 15 equally spaced portions, serving as the finite action space for reinforcement learning and the control input for the system. The network is trained using the DNQ algorithm's experience replay and the separate target network settings. The system state serves as the network input, and the state value corresponding to each action in the action space serves as the output. A two-layer neural network with 20 hidden nodes is designed as the evaluation network and target network, using RELU as the hidden layer activation function.

[0067] Execute an action to obtain a new weight factor, and store the new weight factor in a memory bank;

[0068] The weight factors are determined according to the weight factors in the memory bank; and the control system determines the control signal of the magnetic levitation console according to the weight factors.

[0069] Example 4

[0070] Based on the above embodiment, the magnetic levitation controller of this embodiment adopts ST's STM32F103ZET6 as the main control chip; the digital tube display and keyboard are directly controlled and detected by the STM32F103ZET6; the AC voltage regulation circuit is controlled by the STM32F103ZET6 to achieve voltage regulation; the coil suspension generates an analog signal by driving the sliding rheostat, which is converted by the serial port AD conversion circuit and sent to the STM32F103ZET6 to achieve closed-loop control of the coil height;

[0071] The AC magnetic levitation controller can set relevant parameters through the digital tube display and the four buttons (SW1~SW4) in the lower left corner of the keyboard circuit, which can realize the AC magnetic levitation controller to control the speed of the three-phase AC motor.

[0072] SW1 and SW2 are the start and stop buttons, respectively used to start and stop the AC magnetic levitation controller; SW3 is the height increase button; SW4 is the height decrease button. Specific requirements include the following: Press the "↑" or "↓" button to set the AC magnetic levitation coil height, with a setting range of 00.0 mm to 30.0 mm. The set value is displayed in millimeters on the last three of the four right-hand digital tubes. Press the start button to start the AC magnetic levitation controller, and press the stop button to stop it. The controller must be stopped upon startup, and the AC magnetic levitation coil height displays "00.0." The AC magnetic levitation coil height can be set before and after startup. Human-machine interaction is clear, stable, and shadow-free via the front panel digital tube display, with the highest frequency digit blanked. Different values are displayed according to the function requirements. Debounce the buttons to prevent incorrect key presses.

Claims

1. A control method for AC magnetic levitation, characterized in that the method include: S1: Determination of control factors. Determine the factors that affect the control of AC magnetic levitation and summarize them. The control factors include the mass of the coil, constant, acceleration of gravity, voltage across the coil, coil resistance, coil inductance, and operating point. S2: Determine the control object comments, classify the control objects of the AC magnetic levitation, and determine the object comment set; S3: Determination of weight factors. In S1 and S2, different control factors will lead to different effects, thus determining the control weight factors of AC magnetic levitation; The controller uses the offset of the magnetic levitation coil from the operating point, the speed, the voltage, and the control current as state inputs. The network is trained by replaying the experience in the DNQ algorithm and setting the target network separately. The system state is used as the network input, and the state value corresponding to each action in the action space is used as the output. The neural network is used as the evaluation network and the target network, and RELU is used as the hidden layer activation function. The random strategy is used for exploration and filling the memory bank. Determine the action to be performed through a greedy strategy; Execute an action to obtain a new weight factor, and store the new weight factor in a memory bank; Determine the weight factors based on the weight factors in the memory bank; S4: determining a control signal of the AC magnetic levitation according to a weight factor; the weight factor is determined by obtaining the weight factor according to a weighted average state training algorithm.

2. An AC magnetic levitation experimental device, comprising a magnetic levitation controller and a magnetic levitation experimental platform, wherein the magnetic levitation controller sends a control signal to the magnetic levitation control console, and the magnetic levitation control console feeds back a signal to the magnetic levitation controller; characterized in that: The control signal sent by the magnetic levitation controller is a magnetic levitation control signal obtained by the AC magnetic levitation control method according to claim 1.

3. The AC magnetic levitation experimental device according to claim 2, characterized in that: The magnetic levitation console is provided with a magnetic levitation coil, which is connected to a sliding rheostat; the magnetic levitation controller includes a single chip microcomputer and an AC voltage regulation module; When the magnetic levitation coil is suspended, the sliding rheostat receives the height signal of the magnetic levitation coil and transmits the height signal of the magnetic levitation coil to the sliding rheostat, which transmits the signal to the single chip microcomputer, which processes the signal and transmits the processed signal to the AC voltage regulation module; The AC voltage regulating module is connected to the sliding rheostat, and the AC voltage regulating module outputs a pulse signal to control the sliding of the sliding rheostat.

4. The AC magnetic levitation experimental device according to claim 2, characterized in that: The magnetic levitation controller includes a chassis, a front panel, a rear panel and a fixed base plate; the fixed base plate is located at the bottom of the chassis, and the front panel and the rear panel are relatively located on the chassis.

5. The AC magnetic levitation experimental device according to claim 3, characterized in that: The front panel is equipped with a power switch and a training board; the rear panel is equipped with a national standard power socket, a voltage regulating output socket and a power input interface.

6. The AC magnetic levitation experimental device according to claim 2, characterized in that: The chassis is equipped with a core board and a serial port AD conversion circuit board.

7. The AC magnetic levitation experimental device according to claim 2, characterized in that: The training board is equipped with a human-computer interaction interface unit.

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