CN111258338A - Real-time linkage control system for polarizer and antenna - Google Patents

Abstract

The invention belongs to the field of plasma heating, and particularly relates to a polarizer and antenna real-time linkage control system which comprises a control part and a linkage part, wherein the linkage part consists of a linear polarizer, an elliptical polarizer, a focusing mirror, a rotary plane mirror and a servo motor, and the focusing mirror and the rotary plane mirror form an antenna plane mirror; the control part consists of a central controller, two reflective memory cards, two main controllers, two Ethernet switches, two PLC boards and two controllers; the microwave polarization characteristic is changed in real time through linkage of the polarizer and the antenna, so that the coupling efficiency of the electron cyclotron waves and the plasma is ensured, and the diagnostic equipment is prevented from being damaged. The control from the central control signal to the real-time linkage of the polarizer and the antenna is realized through the reflection memory card, the main controller, the Ethernet switch, the PLC and the controller, the high-efficiency and accurate remote control can be carried out under the complex experimental environment, the structure is simple, the reaction speed is high, the control precision is high, and the system is stable.

Description

A real-time linkage control system of polarizer and antenna

technical field

The invention belongs to the field of plasma heating, and in particular relates to a control system in which a polarizer and an antenna are linked in real time.

Background technique

In nuclear fusion research, electron cyclotron resonance heating is an important heating and regulation method in controlled magnetic confinement nuclear fusion. It has the characteristics of good accessibility, high heating efficiency and good localization. Its function is mainly in plasma Body activation, current profile control, inhibition of neoclassical tear membranes, and current drive, etc. In order to use this system to realize the above functions, it is required that the injection angle of the electron cyclotron wave can be changed in real time according to the experimental requirements. The newly developed microwave transmitting antenna already has this function. However, with the change of the microwave injection angle, the purity of the coupled mode is reduced, which leads to the reduction of the coupling efficiency between the wave and the plasma. Electron cyclotron resonance heating systems generally use dual polarizers to achieve arbitrary polarization of microwaves to improve the coupling efficiency between waves and plasma.

Previously, the control of the polarizer was mainly to control the rotation angle of the polarizer manually, which could not be linked with the antenna in real time during the experiment. The coupling efficiency in the body is low, which not only leads to a decrease in heating or driving effect, but also the microwave that cannot be absorbed will propagate to the edge of the device to damage the diagnostic equipment, etc., resulting in serious consequences. According to the requirements of the real-time suppression of the neoclassical tear film experiment, once the tear film is diagnosed, microwaves must be emitted to the center of the tear film to accurately suppress it. In order to improve the suppression efficiency and reduce the possibility of microwave damage to the diagnostic equipment, The polarizer must be linked with the antenna in real time. Due to the short plasma discharge time and the high requirements on the accuracy of the microwave power deposition position, the experimental requirements need to be met in terms of operation time, reaction speed, control accuracy, and remote control.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a kind of polarizer and antenna real-time linkage control system, it can control polarizer and antenna to carry out real-time linkage, and operation time, response speed, control precision etc. meet the requirements.

The technical scheme of the present invention is as follows:

A polarizer and an antenna real-time linkage control system, including a control part and a linkage part, the linkage part is composed of a linear polarizer, an elliptical polarizer, a focusing mirror, a rotating plane mirror and a servo motor, wherein the focusing mirror and the rotating The plane mirror forms the antenna plane mirror;

The linear polarizer is installed in the microwave emission direction, the direction of the microwave is changed by the linear polarizer, and the elliptical polarizer is installed in the changed direction of the microwave, and the direction of the microwave is changed again and emitted to the focusing mirror, and is reflected by the mirror surface. On the rotating plane mirror, it is emitted to the plasma through the rotating plane mirror, and the rotation direction of the rotating plane is controlled by the servo motor;

Described control part is made up of central controller, two reflective memory cards, two main controllers, two ethernet switches, two PLC boards, two controllers;

In the control part, the reflective memory card, the main controller, the Ethernet switch, the PLC board, and the controller form two control loops with the same structure, which are respectively connected with the central controller;

The controllers on the two control loops, namely the first controller and the second controller, the first controller controls the rotation of the rotating plane mirror by controlling the servo motor, and the second controller controls the elliptical polarizer and the linear polarizer angle of rotation;

The PLC boards on the two control loops, as well as the first PLC and the second PLC, according to the set parameters of the servo motor rotation and the rotation angle signals of the rotating plane mirror and the polarizer received respectively, the first controller and the second PLC respectively. The controller sends a rotation command;

The main controllers on the two control loops, namely the first main controller and the second main controller, are used to receive central control instructions;

The Ethernet switches on the two control loops, namely the first Ethernet switch and the second Ethernet switch, are used to realize that the corresponding first main controller and the second main controller respectively send the rotating plane mirror and the dual polarizer The long-distance transmission of the real-time rotation angle;

The reflective memory cards on the two control loops are the first reflective memory card and the second reflective memory card, which are used for real-time optical fiber signal transmission between the central controller and the first main controller and the second main controller respectively.

The described first main controller is used to complete the calculation of the real-time rotation angle of the rotating plane mirror, and to send the real-time rotation angle signal and the motor start signal to the first PLC module; the described second main controller is used to complete the dual polarizer. Calculate the real-time rotation angle, and send the real-time rotation angle signal to the second PLC module.

The real-time rotation angle calculation method of the dual polarizer is as follows:

3.1) For any angle m within the range of (00 1800] that the linear polarizer can rotate to, there is any angle that the elliptical polarizer can rotate to within the range of (00 1800]. An angle n corresponds to it;

3.2) By theoretical calculation of 3,240,000 combinations, a two-dimensional matrix of 1800×1800 can be obtained. The elements in the i-th row and the j-th column of the matrix are expressed in the form of η _ij , where η _ij represents the coupling efficiency of the wave in the plasma when the elliptical polarizer is rotated to an angle of i-1, and the linear polarizer is rotated to an angle of j-1 n;

3.3) Find the maximum value η _ij among all the coupling efficiencies, and return the angle i-1 of the elliptical polarizer, the angle j-1 of the linear polarizer, and the angle i-1 corresponding to the maximum efficiency η _ij and j-1 are the angles to which the elliptical polarizer and the linear polarizer need to be rotated respectively;

3.4) If there are multiple identical maximum values η _ij in all coupling efficiencies, it is necessary to judge which maximum value to choose;

3.5) Let the current angle of the elliptical polarizer be i _c , and the current angle of the linear polarizer be j _c , then the angle i-1 of the elliptical polarizer and the angle j of the linear polarizer corresponding to all the maximum values η _ij The distance between -1 and the current angle of the elliptical and linear polarizers is S

Among all S values, the angle i-1 of the elliptical polarizer corresponding to the minimum value is taken, and the angle j-1 of the linear polarizer is the angle to which the elliptical polarizer and the linear polarizer need to be rotated respectively.

The communication time from the central controller sending the signal to the sending of the memory card and receiving the signal is controlled to be 0 to 50 microseconds.

The real-time control mode time of the first main controller is less than 10 microseconds, and the real-time control mode time of the second main controller is less than 10 milliseconds.

The first main controller and the second main controller are sent to the real-time rotation angle of the rotating plane mirror and the dual polarizer through the Modbus TCP/IP protocol, based on the transmission of the remote communication unit formed by the Ethernet switch and the Mobdus TCP/IP protocol The time is within 40ms.

The first controller controls the rotation precision of the antenna plane mirror to be 0.146°, and the second controller controls the rotation precision of the polarizer to be 0.1°

The significant effects of the present invention are as follows: the polarization characteristics of the microwave can be changed in real time through the linkage between the polarizer and the antenna, so as to ensure the coupling efficiency of the electron cyclotron wave and the plasma, and prevent damage to the diagnostic equipment. Through the reflection memory card, the main controller, the Ethernet switch and the PLC, the controller realizes the control from the central control signal to the real-time linkage of the polarizer and the antenna. It can carry out efficient and accurate remote control in a complex experimental environment. The structure is simple, Fast response, high control precision and stable system.

Description of drawings

Fig. 1 is a kind of schematic diagram of a polarizer and an antenna real-time linkage control system;

Figure 2 is a control flow chart.

Detailed ways

The present invention will be further described below through the accompanying drawings and specific embodiments.

As shown in Figure 1, a polarizer and antenna real-time linkage control system, the control part consists of a central controller, two reflective memory cards, two main controllers, two Ethernet switches, two PLC boards, two It consists of a controller; the linkage part consists of a linear polarizer, an elliptical polarizer, a focusing mirror, a rotating plane mirror and a servo motor, wherein the focusing mirror and the rotating plane mirror form an antenna plane mirror.

The linear polarizer is installed in the direction of microwave emission, the direction of the microwave is changed by the linear polarizer, and the elliptical polarizer is installed in the changed direction of the microwave, and the direction of the microwave is changed again and emitted to the focusing mirror, and then reflected by the mirror to the rotating plane mirror , which is emitted into the plasma through a rotating plane mirror. The direction of rotation of the rotating plane is controlled by a servo motor.

The control part includes a central controller, and two control loops respectively connected to the central controller. Each control loop includes a reflective memory card, a main controller, an Ethernet switch, a PLC board and a controller sequentially connected to the central controller.

Among them, the controllers on the two control loops, namely the first controller and the second controller, the first controller controls the rotation of the rotating plane mirror by controlling the servo motor, and the second controller controls the elliptical polarizer and the linear polarizer. the rotation angle of the device.

The PLC boards on the two control loops, as well as the first PLC and the second PLC, according to the set parameters of the servo motor rotation and the rotation angle signals of the rotating plane mirror and the polarizer received respectively, the first controller and the second PLC respectively. The controller sends a rotation command;

The Ethernet switches on the two control loops, namely the first Ethernet switch and the second Ethernet switch, are used to realize that the corresponding first main controller and the second main controller send to the rotation through the Modbus TCP/IP protocol. Long-distance transmission of real-time rotation angles of plane mirrors and dual polarizers (elliptical polarizers and linear polarizers);

The main controllers on the two control loops, namely the first main controller and the second main controller, are used to receive central control instructions.

The first main controller is used to complete the calculation of the real-time rotation angle of the rotating plane mirror, and send the real-time rotation angle signal and the motor start signal to the first PLC module; the second main controller is used to complete the calculation of the real-time rotation angle of the dual polarizer, And send the real-time rotation angle signal to the second PLC module,

Among them, the real-time rotation angle of the dual polarizers (elliptical polarizer and linear polarizer) is calculated by the following method.

After the incident microwave is reflected by the dual polarizer, the relationship between the reflected wave (E _xr E _yr ) and the incident wave (E _xi E _yi ) is:

代表线极化器的参数， ξ₂＝tan^-1(tanΦ₂cosθ)，

代表椭圆极化器的参数，Φ₁为线极化 器的旋转角度，Φ₂为椭圆极化器的旋转角度，θ为微波入射角度，

和

分 别为TE极化波及TM极化波的零阶衍射系数，水平方向为X轴方向，垂直方 向为Y轴方向。In the formula, ξ1=tan ^-1 (tanΦ1cosθ),

represents the parameters of the linear polarizer, ξ ₂ =tan ^-1 (tanΦ ₂ cosθ),

represents the parameters of the elliptical polarizer, Φ ₁ is the rotation angle of the linear polarizer, Φ ₂ is the rotation angle of the elliptical polarizer, θ is the microwave incident angle,

and

are the zero-order diffraction coefficients of the TE polarized wave and the TM polarized wave, respectively, the horizontal direction is the X-axis direction, and the vertical direction is the Y-axis direction.

When the incident wave reaches the plasma boundary, the wave mainly contains two parts, the X mode and the O mode, and the electric fields of these two parts are represented _{by Ex} and E _o respectively. If the wave incident into the plasma only contains E _x , it means that all the power of the incident wave is coupled in the X mode. Similarly, if the wave incident into the plasma contains only E _o , it means that all the power of the incident wave is in the form of O-mode coupling.

According to the dispersion theory of cold plasma, the ratio of the incident wave electric field component E _p in the X-axis and Y-axis directions is determined as follows:

与磁场

之间的夹角，

ω_ce是电子回旋 共振频率，m_e是电子的质量，e是电子的电荷量，f是微波的频率。where ψ is the wave vector

with magnetic field

the angle between

ω _ce is the electron cyclotron resonance frequency, me is the mass of the electron, _e is the charge of the electron, and f is the frequency of the microwave.

When microwaves are coupled in the plasma, the ratio of _Ex and E _o can be expressed as:

After the microwave is incident into the plasma, it will be coupled into the X mode and the O mode, where the ratio of the X mode and the O mode is as follows:

来确定。From the above expression, it can be seen that (E _xr E _yr ) is determined by the dual polarizer, and (K _X K _o ) is determined by the magnetic field strength B at the plasma boundary and the wave vector k of the incident wave and the magnetic field strength B. The included angle χ is determined. The included angle χ is determined by the incident angle of the incident wave

to make sure.

都能计算出获得注入模在最大纯度情况下，双极化 器分别需要旋转的角度，即为双极化器(椭圆极化器和线极化器)的实时转动 的角度。corresponding to each

All of them can calculate the angle that the dual polarizers need to rotate in the case of obtaining the maximum purity of the injection mode, which is the real-time rotation angle of the dual polarizers (elliptical polarizer and linear polarizer).

Whether the microwave and plasma can be efficiently coupled is related to the strength of the plasma magnetic field, the incident angle of the antenna and the matching degree of the polarization characteristics of the microwave. Plasma experiments are guided by physical requirements, which determine the strength of the plasma's magnetic field and the angle of incidence of the antenna. In order to ensure that the microwave can be efficiently coupled with the plasma, the strategy of actively matching the polarization characteristics of the microwave with the magnetic field strength and the incident angle of the antenna is adopted.

According to the received plasma magnetic field strength and the incident angle of the antenna, the relationship between the coupling efficiency of the wave in the plasma and the rotation angle of the linear polarizer and the elliptical polarizer is calculated.

1) For any angle m that the linear polarizer can rotate to within the range of (0° 180°], there is an elliptical polarizer that can be rotated to the value range of (0° 180°). ] corresponds to any angle n in it.

The rotation angle accuracy of the linear polarizer and the elliptical polarizer is 0.1°, and there are 1800×1800=3240000 combinations of all (m n), that is, a total of 3240000 coupling efficiency values.

2) By theoretical calculation of 3,240,000 combinations, a two-dimensional matrix of 1800×1800 can be obtained. The elements in the i-th row and the j-th column of the matrix are expressed in the form of η _ij . η _ij represents the coupling efficiency η of the wave in the plasma when the elliptical polarizer is rotated to an angle of i-1, and the linear polarizer is rotated to an angle of j-1.

3) Find the maximum value η _ij among all the coupling efficiencies, and return the angle i-1 of the elliptical polarizer, the angle j-1 of the linear polarizer, and the angle i-1 corresponding to the maximum efficiency η _ij and j-1 are the angles to which the elliptical polarizer and the linear polarizer need to be rotated, respectively.

4) If there are multiple identical maximum values η _ij in all coupling efficiencies, it is necessary to judge which maximum value η _ij is to be selected.

5) Let the current angle of the elliptical polarizer be _{ic and the current angle of the linear polarizer to be j c ,} then the angle i-1 of the elliptical polarizer and the angle j of the linear polarizer corresponding to all the maximum values η _ij The distance between -1 and the current angle of the elliptical and linear polarizers is S, which is defined as:

Among all S values, take the angle i-1 of the elliptical polarizer corresponding to the smallest S value, and the angle j-1 of the linear polarizer is the angle to which the elliptical polarizer and the linear polarizer need to be rotated respectively. angle.

The reflective memory cards on the two control loops are the first reflective memory card and the second reflective memory card, which are used for real-time optical fiber signal transmission between the central controller and the first main controller and the second main controller respectively;

The communication time from the central controller sending the signal to the sending of the memory card and receiving the signal is controlled to be 0 to 50 microseconds.

The real-time control mode time of the first main controller is less than 10 microseconds, and the real-time control mode time of the second main controller is less than 10 milliseconds.

The transmission time of the remote communication unit based on the Ethernet switch and Mobdus TCP/IP protocol is within 40 milliseconds;

The first controller controls the rotation precision of the antenna plane mirror to be 0.146°, and the second controller controls the rotation precision of the polarizer to be 0.1°

The signals sent by the central controller include the poloidal magnetic field of the plasma boundary, the poloidal magnetic field at the magnetic axis, the toroidal magnetic field of the plasma boundary, the position of the large radius of the tokamak, the size of the large radius of the calculation area, the minimum radial position, the polar To flux grid, toroidal magnetic field grid, plasma density.

It takes less than 250 milliseconds from the signal sent from the central controller to the arrival of the rotating mirrors and dual polarizers at their designated positions.

The control workflow of the control system in which the polarizer and the antenna are linked in real time is described with reference to FIG. 2 .

After the central controller processes the information of the plasma diagnosis, the information is simultaneously sent to the first main controller and the second main controller through the first reflection memory card and the second emission memory card. The first main controller runs the real-time wave trajectory program according to the information, calculates the angle that the antenna plane mirror needs to rotate, and then transmits the incident angle to the first PLC through the first Ethernet, and the first PLC calculates the parameters of the motor rotation and sends it to the first PLC. A controller, the first controller controls the rotation of the servo motor to drive the plane mirror to the specified position; at the same time, the second main controller runs the real-time wave trajectory program and the wave-plasma coupling program according to the information, and calculates that the polarizer needs to be rotated Then the angle is transmitted to the second PLC through the second Ethernet, the second PLC calculates the motor rotation parameters and sends them to the second controller, the second controller drives the linear polarizer and the elliptical polarizer to rotate to the specified angle.

Claims (7)

1. The utility model provides a real-time coordinated control system of polarizer and antenna, includes control part and linkage part, its characterized in that:

the linkage part consists of a linear polarizer, an elliptical polarizer, a focusing mirror, a rotary plane mirror and a servo motor, wherein the focusing mirror and the rotary plane mirror form an antenna plane mirror;

the linear polarizer is arranged in the microwave transmitting direction, the microwave direction is changed by the linear polarizer, the elliptical polarizer is arranged in the changed microwave direction, the microwave direction is changed again and transmitted to the focusing mirror, the microwave is reflected to the rotating plane mirror through the mirror surface and is transmitted to the plasma through the rotating plane mirror, and the rotating direction of the rotating plane is controlled by the servo motor;

the control part consists of a central controller, two reflective memory cards, two main controllers, two Ethernet switches, two PLC boards and two controllers;

in the control part, the reflection memory card, the main controller, the Ethernet switch, the PLC board and the controller form two control loops with the same structure, and the two control loops are respectively connected with the central controller;

controllers on the two control loops, namely a first controller and a second controller, wherein the first controller controls the rotation of the rotary plane mirror by controlling the servo motor, and the second controller controls the rotation angles of the elliptical polarizer and the linear polarizer;

the PLC boards on the two control loops, the first PLC and the second PLC respectively send rotation commands to the first controller and the second controller according to the set rotation parameters of the servo motor and the rotation angle signals of the rotary plane mirror and the polarizer respectively received;

the main controllers on the two control loops, namely the first main controller and the second main controller, are used for receiving a central control instruction;

the Ethernet switches on the two control loops, namely the first Ethernet switch and the second Ethernet switch, are used for realizing that the corresponding first main controller and the corresponding second main controller respectively send the remote transmission of the real-time rotation angle of the rotating plane mirror and the dual-polarization device;

the reflective memory cards on the two control loops are a first reflective memory card and a second reflective memory card, and are used for real-time optical fiber signal transmission between the central controller and the first main controller and between the central controller and the second main controller respectively.

2. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein: the first main controller is used for completing the calculation of the real-time rotation angle of the rotating plane mirror and sending a real-time rotation angle signal and a motor starting signal to the first PLC module; the second main controller is used for completing calculation of the real-time rotation angle of the dual-polarization device and sending a real-time rotation angle signal to the second PLC module.

3. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein the real-time rotation angle calculation method of the dual polarizer is as follows:

3.1) for any angle m within the rotatable angle range (0 degrees 180 degrees) of the linear polarizer, any angle n within the rotatable angle range (0 degrees 180 degrees) of the elliptical polarizer corresponds to the angle m;

3.2) by theoretical calculation of 3240000 combinations, a 1800X 1800 two-dimensional matrix can be obtained, wherein the ith row and the jth column elements in the matrix are η_ijForm representation, η_ijIndicating the coupling efficiency η of the wave in the plasma when the elliptical polarizer is rotated to an angle of i-1 and the linear polarizer is rotated to an angle of j-1;

3.3) finding the maximum η among all the coupling efficiencies_ijAnd returns the maximum efficiency η_ijThe corresponding angle i-1 of the elliptical polarizer and the angle j-1 of the linear polarizer, wherein the angles i-1 and j-1 are the angles to which the elliptical polarizer and the linear polarizer need to rotate respectively;

3.4) if there are multiple identical maxima η in all coupling efficiencies_ijThen, it is necessary to determine which maximum value to select;

3.5) let the current angle of the elliptical polarizer be i_cCurrent angle of linear polarizer is j_cAll maximum values η_ijThe distance between the angle i-1 of the corresponding elliptical polarizer and the angle j-1 of the linear polarizer and the current angles of the elliptical polarizer and the linear polarizer is S

And in all S values, taking the angle i-1 of the elliptical polarizer corresponding to the minimum value, wherein the angle j-1 of the linear polarizer is the angle to which the elliptical polarizer and the linear polarizer need to rotate respectively.

4. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein: the communication time from the signal sending of the central controller to the signal receiving of the transmitting memory card is controlled to be 0-50 microseconds.

5. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein: the real-time control mode time of the first main controller is less than 10 microseconds, and the real-time control mode time of the second main controller is less than 10 milliseconds.

6. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein: the first main controller and the second main controller send real-time rotation angles of the rotary plane mirror and the dual-polarization device through a Modbus TCP/IP protocol, and transmission time of a remote communication unit formed on the basis of an Ethernet switch and a Mobdus TCP/IP protocol is within 40 milliseconds.

7. The real-time linkage control system of the polarizer and the antenna according to claim 1, wherein: the first controller controls the rotation precision of the antenna plane mirror to be 0.146 degrees, and the second controller controls the rotation precision of the polarizer to be 0.1 degrees.

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