KR0172156B1 - Main gate contamination monitoring device using one chip microcontroller - Google Patents

Abstract

The present invention relates to a front door radiation pollution monitoring device using a one-chip microcontroller, installed in the front door of the place handling the radioactive material to monitor the contamination state lamp, LED, alarm device, proximity sensor, back sensor, confirmation switch It has a buffer connected to one main module and connected to the LCD panel, keypad and power, the main module is connected to six counter modules, the main module and the counter module is a one-chip microcontroller.

Description

Front Door Radiation Monitoring System Using One-chip Microcontroller

1 is an overall circuit diagram of a front door radiation pollution detection device.

2 is a main module configuration diagram.

3 is a counter module configuration diagram.

4 is a general configuration of the monitoring device program.

5 is a flowchart of a monitoring device operation program.

6 is a main module circuit diagram.

7 is a counter module circuit diagram.

The present invention relates to a front door radiation contamination monitoring apparatus using a one-chip microcontroller.

The front gate radiation pollution monitoring device is installed at the entrance of nuclear facilities such as nuclear power plants that handle radioactive materials, and monitors radioactive pollution or illegal spills of radioactive materials when entering or exiting the facility.

Conventionally, since the components for input and output are separately used using a general microprocessor in the control unit, the number of parts used is large, and the counter circuits (modules) are connected to the detection signals from the respective detectors (11 to 13) through a common cable. Because of the complicated wiring, maintenance and repair are not easy. Manpower and materials are required for manufacturing. Since the bias voltage (high voltage) to each detector is supplied uniformly from one power source, the optimum bias for each detector is changed. Could not set voltage.

The present invention is to remove the above-described drawbacks in detail as follows in connection with the embodiments and the accompanying drawings.

In the equipment configuration, the main body has a rectangular frame, and 11 GM counters are arranged on the frame to measure radiation contamination (β, γ) of the head, shoulders, arms, legs, and feet. The display part is installed on the frame head so that the user can easily observe the operation status during the measurement, and 6 lamps (preparation, measurement, remeasurement, normal, contamination, failure) and 11 LEDs (GM counter and 1: 1) Correspondence).

When the user enters the monitoring device, the measurement starts, and if the measurement exceeds the limit after the measurement for a predetermined time, the corresponding position is indicated on the LED display arranged in silhouette form and the pollution indicator lamp and the alarm sound are raised.

The electronic circuit consists of one main module, six counter modules, input devices, a power circuit and a data bus. The main module controls 6 counter modules through the data bus to count the pulses of the GM counter, synthesize and process the measured data, and output the result through the display.

The counter module generates and supplies high voltage to operate GM counter and counts the number of pulses outputted from GM counter for a predetermined time by using 16bit binary counter and transmits it to main module.

Input device consists of LCD and keyboard and is used for setting value change and function test.

The main module and counter modules use Intel 8751 one-chip microcontroller, the main point of the invention is to implement the control part (main module) using the one-chip microcontroller, the counter module using the one-chip microcontroller, the main module and the counter Data transfer between modules is implemented using RS422 serial communication method, high voltage adjustment is implemented by software using keypad using digital potentiometer, and data (setting value) is monitored by using LCD and keypad. It is implemented in software to execute input and test operations.

In the configuration of the present invention, the electronic circuit of the front gate radiation pollution monitoring device is composed of one main module, six counter modules, a display device, an input device, a power supply circuit, a data bus and the like as shown in FIG.

The main module controls the counter module connected by the data bus, collects the necessary data, analyzes it, and outputs it through the display and alarm.

As shown in FIG. 2, it consists of an Intel i8751 microcontroller, i8255, a general-purpose LSI for parallel input / output, and an optical isolation circuit and a buffer connecting the peripheral device and the peripheral device.

The peripheral devices connected to the main module are as follows.

(1) Lamp: It displays the operation status of the monitoring device (ready-measurement-remeasurement-normal-contamination-fault) and the measurement result.

(2) LEDs: 11 LEDs are arranged in a human silhouette to indicate contaminated areas of the subject.

(3) LCD and keypad: Used for initial value setting and operation test.

(4) Climbing sensors: check that the subject is correctly mounted on the monitoring device.

(5) Acknowledgment switch (Act SW): Used to confirm the operation of the subject and user in detecting contamination and system failure.

(6) Alarming device: Ringing when detecting contamination and system failure

(7) Counter module: Supply the high voltage determined according to the instruction of main module to the detector and count the pulse output from the detector.

3 shows a counter module, which includes two count channels, a high voltage generating circuit, an ADC and a digital potentiometer required to read and control the current supply voltage, an RS-422 interface circuit for connecting to the main module, and commands transmitted from the main module. It consists of a microcontroller i8751 for interpreting and executing.

4 shows the overall flowchart of the monitoring device operation program.

The overall structure of the monitoring program consists of self-diagnosis routine, initialization routine, operation test routine, and execution routine.

When power is supplied to the monitoring device, the program of the main module is the first routine to be executed before entering the measurement operation. It is supplied to the display device check, counter module check, detector, high voltage check, peripheral dose update and fault detector diagnosis.

The display unit checks the six lamps on the display in the order of ready-measurement-measurement-normal-contamination-fault and the 11 LEDs of the silhouette blink three times simultaneously, allowing the administrator to check the health of the lamps and LEDs. do.

In order to check the counter module, reset 6 counter modules connected by RS-422 bus by reset line, and then call 6 modules in order from 1 to 6 to check the response. If it is reset and there is no response to the 3rd call, it is regarded as a failure of the counter module and the 'Fault' lamp is turned on and an alarm is issued. The LED silhouette is also used to indicate a faulty module and the LCD also displays 'Module Fault'.

When all six counter modules respond, the main module checks the high voltage of each counter module supplied to the detector. Transmit high voltage set value stored in RAM of main module which is input in advance to the relevant counter module and measure high voltage output. If there is difference over ± 10V from set value, 'Fault' lamp is turned on and alarm is issued. In addition, the LED silhouette is used to indicate the failed module and the LCD displays 'High Volt Fault'.

In the peripheral dose update and fault detector diagnosis, the output pulses of each detector are counted six times during the basic measurement time (5 seconds) and averaged, and then used as the peripheral dose value. This value is updated every minute during the non-measurement time.

Ambient dose values are used to compensate for the effects of ambient sources during the measurement. If the measured ambient dose value is greater than the set value or no value is detected, update the ambient dose value once again and if the same result is obtained, the monitoring device turns on the 'contamination' lamp and generates an alarm. The LED silhouette is also used to display contaminated or broken detectors and the LCD displays 'BKG Contam'. At this time, to check the measured peripheral dose value, press 'ESC' on the keyboard to display a menu such as '(1) SETUP / (2) INSIGHT / (3) RUN'. Press '2' to select 'INSIGHT'. And select 'VIEW' again and input the corresponding counter module number.

Press the 'ESC' key on the keyboard with the 'Ready' or 'Fouling' lamp turned on after the self-test of the monitoring device is finished.The menu of '(1) SETUP / (2) INSIGHT / (3) RUN' is displayed on the LCD. Press '1' key to select 'SETUP'. Then go back to '(1) CTIME / (2) SK_

SP / (3) RESET / (4) HV / (5) SP 'is displayed. Each function is as follows.

-CTIME: It indicates the measurement time. It is set as 5 seconds as default value and can be changed arbitrarily. Selecting the Time menu will display the currently set time and prompt you to enter a new value. If you do not want to change it, press 'ESC' or 'CR' key to return to the previous menu screen.

-BK_SP: This is the standard value for ambient pollution judgment. It is set as 20 by default and can be set differently for each detector. If you select BK_SP menu, you need to input the number of the counter module that you want to check or change the BK_SP value. Use 1-6 keys to select the module. The current BK_SP value is displayed in the form of 'A / B =?,?'. The next line is waiting for input of a new BK_SP value. The new value can be entered in the form of '15, 20 '.

-RESET: Reset all counter modules.

-HV: It is responsible for setting the high voltage supplied to each detector and can be set differently for each counter module. If you select the HV menu, you need to input the number of the counter module that you want to check or change the HV value. If you select the module using 1-6 keys, the current HV value is displayed in the form of 'Now Volt = 1200'. Waiting for new HV value.

Enter the new value and press the 'CR' key. The current high voltage is continuously updated and appears on the LCD screen. If a large difference is found between the setpoint and the measured value, it should be calibrated according to the calibration procedure.

-SP: Set Point for pollution determination, set to 15 by default and can be set differently for each detector. If you select SP menu, you are required to input the number of the counter module you want to check or change the SP value. If you select the module using 1-6 keys, the current SP value is displayed in the form of 'A / B =?,?'. The next line is waiting for input of new SP value. The new value can be entered in the form of '15, 20 '.

After performing the initialization routine, reset the main module, turn the power off and then on again, or select 'RUN' from the menu of '(1) SETUP / (2) INSIGHT / (3) RUN' to start the measurement operation. . The program flow chart of the measurement operation is shown in FIG.

Modifications of the present invention are as follows.

-The CPU used for the main module and the counter module can be implemented using other CPUs of the i8051 series, and the signal shaping circuit for the counter module GM counter is used as the signal shaping circuit for other radiation detectors (e.g., proportional counter, scintillation counter). It can be configured alternatively and the data transmission method between the main module and the counter module can be implemented by using another communication protocol having a multi-drop function.

Thus, the present invention has the effect of reducing the probability of failure due to the reduction of the number of parts by the use of the one-chip microcontroller, and the wiring at the time of manufacture because it is composed of a bus type employing a serial communication method for data transmission between the main module and the counter module. The reduction of work also reduces the amount of manpower and user materials.

Claims (3)

In order to monitor the contamination by installing at the front door of the place where radiation is handled, connect the buffer with lamp, LED, alarm device, proximity sensor, back plate sensor and confirmation switch to one main module and connect it to LCD panel, keypad and power supply. And the main module connects six counter modules to the main module, and the main module and the counter module are one-chip microcontrollers. The front gate radiation contamination monitoring apparatus using a one-chip microcontroller according to claim 1, wherein the main module and the counter module each have a separate CPU and are configured as a bus using an RS-422 communication method between modules. The front gate radiation contamination monitoring apparatus using a one-chip microcontroller according to claim 1, comprising two independent channels to process signals from two detectors per counter module.