CN104979742A - Chemical oxygen-iodine laser optical resonant cavity adjusting and monitoring system and method - Google Patents

Abstract

The invention relates to a system and method for adjusting and monitoring an optical resonant cavity of an oxygen-iodine chemical laser, comprising: a main control module, an algorithm module, a data acquisition module, a motor control module, a digital I/O module, a motor-driven digital I/O module, and a communication module , a display unit and a power supply module; the method includes that the main control module collects and displays the intracavity pressure data of the pressure sensor in real time, and judges whether the collected intracavity pressure data exceeds the allowable range of the pressure in the optical cavity; the algorithm module sends instructions to the optical cavity according to the pressure data in the optical cavity The digital IO module further controls the solenoid valve switch to realize pressure adjustment; the display unit sends a control signal to the motor control module to control the X-direction and Y-direction motors of the cavity mirror to adjust, and monitor the motor running status in real time. The invention has the advantages of strong real-time performance, high stability, simple operation and low development cost, and is especially suitable for the optical resonant cavity of the oxygen iodine chemical laser.

Description

Oxygen-iodine chemical laser optical cavity adjustment and monitoring system and method

technical field

The invention relates to a system and method for adjusting and monitoring the optical resonant cavity of an oxygen iodine chemical laser, in particular to a system and method for adjusting the cavity mirror frame in the optical resonant cavity of an oxygen iodine chemical laser and the internal parameters of the optical resonant cavity. A control system and method for monitoring and controlling.

Background technique

The optical resonator is an important part of the oxygen iodine chemical laser, the adjustment of the cavity mirror and the change of the cavity parameters will directly affect the beam quality of the laser output light. The existing control system separates the two functions of cavity mirror adjustment and optical cavity parameter monitoring and control. The cavity mirror adjustment is composed of motor, power supply and manual button, which can only be adjusted locally; the optical cavity parameter monitoring and control is controlled by The master console is completed further away from the laser position. The function of the system is scattered, the real-time performance is weak, the operation is complex and the anti-interference ability is poor, which is not conducive to the realization of the integrated system of the oxygen iodine chemical laser.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a system and method for adjusting and monitoring the optical resonant cavity of an oxygen-iodine chemical laser with strong real-time performance, high stability, simple operation and low development cost.

Technical solution of the present invention is as follows:

Oxygen iodine chemical laser optical resonator adjustment and monitoring system, including: main control module, algorithm module, data acquisition module, motor control module, digital I/O module, motor drive digital I/O module, communication module, display unit and power supply module;

The main control module is connected with the algorithm module, the digital I/O module and the communication module respectively, the algorithm module is connected with the data acquisition module, the motor control module, and the motor-driven digital I/O module, and the power supply module is connected with the main control module and the general purpose module respectively. The I/O module, the data acquisition module and the motor control module are connected; the communication module is connected with the display unit;

The main control module is used to send the control command received through the display unit to the digital I/O module, and the status of the solenoid valve fed back by the digital I/O module, the pressure sensor information collected by the data acquisition module and the motor drive digital I/O module The feedback motor running status information is displayed in real time through the display unit;

The algorithm module is used to calculate the pressure sensor information collected by the data acquisition module and the motor running status information collected by the motor drive digital I/O module, and send instructions to the digital IO module and the motor control module;

The digital I/O module is used to connect with the solenoid valve and control the opening and closing of the solenoid valve according to the instructions sent by the algorithm module through the main control module;

The data acquisition module is used to collect the data of the intracavity pressure sensor;

The motor drive digital I/O module is connected to the motor control module, and is used to obtain motor running status information by accessing the motor control module and feed it back to the algorithm module.

The oxygen-iodine chemical laser optical resonant cavity adjustment and monitoring system also includes a cavity mirror driving mechanism, which is composed of a mirror frame and a push-pull rod; The mirror is embedded in the Y-direction adjusting frame, the X-direction adjusting frame is set in the Y-direction adjusting frame through the first rotating shaft, and the Y-direction adjusting frame is arranged in the frame through the second rotating shaft; on the X-direction adjusting frame, a second A push-pull rod, a second push-pull rod is provided on the Y-direction adjustment frame in the vertical mirror direction, the first push-pull rod and the second push-pull rod are connected to the first motor and the second motor respectively, and the first and second motors drive the first motor respectively 1. The second push-pull rod reciprocates in a direction perpendicular to the reflective surface of the mirror body.

The first rotation axis is perpendicular to the second rotation axis and located on the same plane.

The cavity mirror is a convex mirror or a concave mirror.

A method for adjusting and monitoring an oxygen-iodine chemical laser optical resonator, comprising the following steps:

1) The main control module receives the intracavity pressure data sensed by the pressure sensor collected by the data acquisition module in real time, and sends it to the display unit for real-time display through the communication module after low-pass filtering;

2) The main control module judges whether the pressure data in the cavity exceeds the allowable range of the pressure in the optical cavity; if it does not exceed, perform step 3); if it exceeds, it will alarm through the display unit, and select the solenoid valve through the display unit according to the displayed pressure value in the cavity switch, and then perform step 3);

3) The algorithm module monitors the running state of the motor in real time; according to the light spot shape and brightness uniformity output by the optical resonant cavity, input instructions to the motor control module to control the motors in the X direction and Y direction of the cavity mirror through the display unit to adjust until the light spot shape and brightness uniformity Brightness uniformity meets the set requirements.

The real-time monitoring of motor running state includes the following steps:

The stroke limiting unit of the motor-driven digital I/O module obtains the movement distance of the push-pull rod connected to the output end of the motor by accessing the counter of the motor control card in the motor control module, and judges whether the distance reaches the set threshold;

If it is reached, it will send a signal to the main control module, and the main control module will issue an instruction to stop the motor and give an alarm through the display unit; if it is not reached, it will monitor the output signal of the motor driver in the motor control module; The control module sends a signal, and the main control module sends an instruction to control the motor to stop running; otherwise, go to step 3).

The cavity mirror is a convex mirror or a concave mirror; the convex mirror is used to control the shape of the light spot, and the concave mirror is used to control the brightness uniformity.

Advantage of the present invention compared with prior art:

1. The present invention integrates the two functions of cavity mirror adjustment and optical cavity parameter monitoring and control of the optical cavity of the oxygen-iodine chemical laser optical cavity in the existing control system, and can realize local and long-distance real-time operation of the optical cavity.

2. The present invention simplifies the operation process through the operation software installed on the touch screen upper computer.

3. High system stability and low development cost. The effectiveness of the system is verified by experiments.

Description of drawings

Fig. 1 is a system composition block diagram of the present invention;

Fig. 2 is the core algorithm module flowchart of the present invention;

Fig. 3 is a schematic diagram of the data acquisition module of the present invention;

Fig. 4 is a schematic diagram of the front view of the driving mechanism of the cavity mirror;

Fig. 5 is a schematic side view of the drive mechanism of the cavity mirror;

Fig. 6 is a schematic diagram of the motor control module of the present invention;

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The invention utilizes the Motorola PowerPC750GX processor to form the main control module, controls other functional modules through the main control module, and designs and manufactures an oxygen-iodine chemical laser optical resonator adjustment and monitoring system. The system is equipped with a touch-screen upper computer and built-in operating software, which is easy to use or operate.

As shown in Figure 1, the present invention mainly includes: a main control module, an algorithm module, a data acquisition module, a motor control module, a digital I/O module, a motor-driven digital I/O module, a display unit, a communication module and a power supply module.

The main control module is respectively connected with the algorithm module, the digital I/O module and the communication module. The algorithm module is connected with the data acquisition module, the motor control module, and the motor drive digital I/O module. The power supply module is respectively connected with the main control module, the general I/O module, the data acquisition module and the motor control module. The digital I/O module is connected to the solenoid valve through the I/O interface to realize the control of vacuuming and amplifying the optical resonant cavity. The data acquisition module is connected with the pressure sensor monitoring the parameters of the optical resonant cavity through an analog signal interface. The motor control module is connected with the stepping motor, and realizes the adjustment of the optical resonant cavity mirror frame through the transmission mechanism. The motor drive digital I/O module is connected with the motor control module through the I/O interface to monitor the running status of the stepper motor.

The main control module is composed of Motorola PowerPC750GX processor, synchronous dynamic random access memory SDRAM, flash memory Flash ROM and clock circuit. The synchronous dynamic random access memory is used to store data, and the flash memory is used to store startup programs. The main control module is used Complete integrated control, logic control, communication functions.

As shown in Figure 3, the data acquisition module is composed of an A/D converter, a programmable timer, a high-speed photoelectric isolation chip and a differential circuit. The programmable timer is used for the logic timing control of the A/D converter and the analog output of the pressure sensor After the signal is isolated by the high-speed photoelectric isolation chip, the analog signal is differentiated through the differential circuit, and then sent to the main control module after being collected by the A/D converter.

The A/D converter has a resolution of 16 bits, simultaneous conversion of four channels, and parallel data output.

As shown in Figure 4, the structure of the cavity mirror drive mechanism is as follows: the frame is composed of a frame, an X-direction adjustment frame and a Y-direction adjustment frame, and the cavity mirror (concave mirror or convex mirror) is embedded in the Y-direction adjustment frame. There is a first push-pull rod in the direction vertical to the mirror surface (that is, the plane formed by the X and Y direction adjustment frames) on the lower part of the X-direction adjustment frame, and a second push-pull rod in the direction vertical to the mirror surface on the upper part of the Y-direction adjustment frame. The first push-pull rod and the second push-pull rod The two push-pull rods are connected to the first stepping motor and the second stepping motor respectively, and the stepping motors drive the push-pull rods to reciprocate in a direction perpendicular to the reflective surface of the mirror body.

As shown in Figure 5, the motor control module is composed of a 4-axis stepping motor control card, a stepping motor driver and an interface circuit. The 4-axis stepping motor control card receives instructions from the core algorithm module and sends them to the stepping motor driver with a certain frequency and The stepper motor driver receives the pulse information and direction signal and acts on the stepper motor, and the stepper motor realizes the adjustment of the cavity mirror frame through the transmission mechanism.

As shown in Figure 6, the 4-axis motor control card is selected as PCI-1240U type, and the stepper motor driver is selected as NDC-06 type.

The digital I/O module is composed of I/O expansion unit, relay unit and interface circuit. The I/O expansion unit is composed of 74HC595 and TLP521-4 chips to realize the I/O expansion of the control system. The relay unit is connected with the expansion circuit. The interface circuit realizes the on-off control of the solenoid valve, thereby realizing the control of amplifying gas and vacuuming the optical cavity.

The relay unit selects PCLD-785 type.

The motor-driven digital I/O module is composed of a stroke limiting unit and a drive monitoring unit. The I/O priority is the highest. The stroke limiting unit judges the moving distance of the stepping motor by accessing the counter of the stepping motor control card. When it reaches the set threshold When the stepper motor driver is working abnormally, it sends a signal to the system, and the main control module sends a signal to the system, and the main control module sends command to stop the stepper motor.

The communication module includes RS232 unit and CAN unit. Users can use any of these two communication methods to establish contact between the upper computer and the control system. The communication module enables the main control module to exchange data with the upper computer. According to the exchanged information, the parameters can be set on the man-machine interface of the touch-screen upper computer, and the image display can display the pressure value curve and the shape of the light spot sensed by the pressure sensor. The shape of the light spot is photographed by a camera connected to the display unit. The camera is located inside the optical resonant cavity to photograph the light emitting position, and the captured light spot is used to adjust the mirror of the optical resonant cavity.

The power module provides +12V, +24V system power for the main control module, general I/O module, data acquisition module and motor control module.

The display unit is a touch-screen upper computer, which is equipped with a man-machine interface, which is used to realize the display and adjustment of the pressure in the optical resonant cavity (select the opening and closing of the solenoid valve), and the adjustment of the optical resonant cavity mirror (input the concave mirror and the convex mirror. angle adjustment).

As shown in Figure 2, the algorithm module is composed of a Motorola PowerPC750GX processor, which is mainly used to collect and calculate the data transmitted by the data acquisition module and the motor-driven digital I/O module. Its functions are mainly composed of pressure monitoring algorithm and cavity mirror adjustment algorithm.

Pressure monitoring algorithm: real-time acquisition of the intracavity pressure transmission signal of the pressure sensor, digital filtering is performed by a low-pass filtering algorithm to filter out mains interference, and then sent to the display unit for real-time display. Then it is judged whether the collected data exceeds the allowable range of the pressure in the optical cavity. If it is within the allowable range, continue to the next algorithm cycle; if it exceeds the range, it will alarm and enter the pressure control algorithm. Press the program start button to start the pressure control algorithm. Select the switch of the electromagnetic valve according to the displayed pressure value in the cavity, and then control the change of the pressure in the cavity, and then continue to enter the next algorithm cycle.

Mirror adjustment algorithm: Press the program start button to start the mirror adjustment algorithm and enter the motor initialization step. Determine whether the motor running button is pressed, and if so, send the corresponding direction and pulse signal. The stroke limiting unit judges the moving distance of the stepping motor by accessing the counter of the stepping motor control card. When it reaches the set threshold, it sends a signal to the system, and the main control module issues an instruction to stop the stepping motor and give an alarm indication; When the set threshold is reached, it enters the drive monitoring unit to monitor the output signal of the stepper motor driver. If the stepper motor driver works abnormally, it will send a signal to the system, and the main control module will issue an instruction to stop the stepper motor; otherwise, it will enter the motor control algorithm.

The motor control algorithm controls the stepping motors in the X direction and Y direction behind the convex mirror and the concave mirror respectively according to the output spot shape and brightness uniformity of the optical resonator to adjust: the image is collected by the camera and displayed on the display unit, and then according to the displayed The shape of the light spot and the uniformity of brightness are input on the display unit to rotate the X-direction and Y-direction of the cavity mirror, and the algorithm module controls the corresponding motor movement through the motor control module according to the order. The convex mirror controls the spot shape, and the concave mirror controls the brightness uniformity. Two stepping motors behind each cavity mirror control the rotation of the cavity mirror in the X direction and Y direction respectively until the spot shape is normal and the brightness is uniform, that is, the spot shape is complete, the edge is clear (the edge line is closed and complete), and the brightness has no gradient change .

Claims (7)

1. Oxygen iodine chemical laser optical resonator adjustment and monitoring system, including: main control module, algorithm module, data acquisition module, motor control module, digital I/O module, motor drive digital I/O module, communication module, display unit and power modules; The main control module is connected with the algorithm module, the digital I/O module and the communication module respectively, the algorithm module is connected with the data acquisition module, the motor control module, and the motor-driven digital I/O module, and the power supply module is connected with the main control module and the general purpose module respectively. The I/O module, the data acquisition module and the motor control module are connected; the communication module is connected with the display unit; The main control module is used to send the control command received through the display unit to the digital I/O module, and the status of the solenoid valve fed back by the digital I/O module, the pressure sensor information collected by the data acquisition module and the motor drive digital I/O module The feedback motor running status information is displayed in real time through the display unit; The algorithm module is used to calculate the pressure sensor information collected by the data acquisition module and the motor running status information collected by the motor drive digital I/O module, and send instructions to the digital IO module and the motor control module; The digital I/O module is used to connect with the solenoid valve and control the opening and closing of the solenoid valve according to the instructions sent by the algorithm module through the main control module; The data acquisition module is used to collect the data of the intracavity pressure sensor; The motor drive digital I/O module is connected to the motor control module, and is used to obtain motor running status information by accessing the motor control module and feed it back to the algorithm module. 2. The oxygen-iodine chemical laser optical resonator adjustment and monitoring system according to claim 1 is characterized in that it also includes a cavity mirror drive mechanism, which is made of a mirror frame and a push-pull rod; the mirror frame includes a hollow frame, a ring Shaped X-direction adjustment frame and Y-direction adjustment frame, the cavity mirror is embedded inside the Y-direction adjustment frame, the X-direction adjustment frame is set in the Y-direction adjustment frame through the first rotation axis, and the Y-direction adjustment frame is set in the frame through the second rotation axis ; A first push-pull rod is provided on the X-direction adjustment frame in the vertical mirror direction, and a second push-pull rod is provided on the Y-direction adjustment frame in the vertical mirror direction, and the first push-pull rod and the second push-pull rod are respectively connected with the first motor and the second The motors are connected by transmission, and the first and second motors respectively drive the first and second push-pull rods to reciprocate in a direction perpendicular to the reflecting surface of the mirror body. 3. The optical cavity adjustment and monitoring system for oxygen-iodine chemical laser according to claim 2, characterized in that the first rotation axis and the second rotation axis are vertical and located on the same plane. 4. The oxygen-iodine chemical laser optical cavity adjustment and monitoring system according to claim 2, characterized in that the cavity mirror is a convex mirror or a concave mirror. 5. a kind of oxygen-iodine chemical laser optical cavity adjustment and monitoring method according to claim 1, is characterized in that comprising the following steps: 1) The main control module receives the intracavity pressure data sensed by the pressure sensor collected by the data acquisition module in real time, and sends it to the display unit for real-time display through the communication module after low-pass filtering; 2) The main control module judges whether the pressure data in the cavity exceeds the allowable range of the pressure in the optical cavity; if it does not exceed, perform step 3); if it exceeds, it will alarm through the display unit, and select the solenoid valve through the display unit according to the displayed pressure value in the cavity switch, and then perform step 3); 3) The algorithm module monitors the running state of the motor in real time; according to the light spot shape and brightness uniformity output by the optical resonant cavity, input instructions to the motor control module to control the motors in the X direction and Y direction of the cavity mirror through the display unit to adjust until the light spot shape and brightness uniformity Brightness uniformity meets the set requirements. 6. Oxygen iodine chemical laser optical resonator adjustment and monitoring method according to claim 5, is characterized in that described real-time monitoring motor running state comprises the following steps: The stroke limiting unit of the motor-driven digital I/O module obtains the movement distance of the push-pull rod connected to the output end of the motor by accessing the counter of the motor control card in the motor control module, and judges whether the distance reaches the set threshold; If it is reached, it will send a signal to the main control module, and the main control module will issue an instruction to stop the motor and give an alarm through the display unit; if it is not reached, it will monitor the output signal of the motor driver in the motor control module; The control module sends a signal, and the main control module sends an instruction to control the motor to stop running; otherwise, go to step 3). 7. The oxygen-iodine chemical laser optical cavity adjustment and monitoring method according to claim 5, characterized in that the cavity mirror is a convex mirror or a concave mirror; the convex mirror is used to control the spot shape, and the concave mirror is used to control Brightness uniformity.