Intelligent control of tunnel lighting based on single-chip computer

(Institute of Railway Construction, Academy of Railway Sciences, Beijing 100081, China)

Abstract: The tunnel light controller is a smart switch device designed for tunnel lighting. After installing the tunnel light controller, the patrol personnel can work under good lighting conditions, and at the same time effectively avoid the common light and save energy.
Key words:
Tunnel lighting intelligent controller

At present, the whole country is vigorously promoting the construction of a conservation-oriented society. During the peak of electricity consumption in the summer of the last two years, the country's largest power gap is more than 20 million kilowatts. Many regions have been forced to impose power cuts, which has seriously affected the development of the national economy. At the same time, in the development of railways, the control method of tunnel lights is relatively backward, the awareness of power saving is not strong, and the phenomenon of power waste is more serious. On June 6, 2004, China launched the "Energy Conservation Publicity Week" nationwide and formulated the "Guide to Public Energy Conservation Behavior". It can be seen that it is imperative to realize intelligent control of railway tunnel lighting.

In the railway tunnel lighting system, the AC contactor installed at the tunnel port can be used to close or cut off the power of the tunnel illumination lamp, and the lighting and extinction of the tunnel illumination lamp can be controlled. Before the railway patrol personnel enters the tunnel, the AC contactor is closed to illuminate the tunnel illuminator. When the railway patrol personnel leaves the tunnel, the AC contactor is disconnected to extinguish the tunnel illuminator. The advantage of this is that the patrolman is easy to operate and has less investment in installation. On the other hand, it takes a certain amount of time from the patrol personnel entering the tunnel to getting out of the tunnel. Especially when the tunnel is long, it will take more time, which will inevitably result in waste of electric energy. What is more serious is that in some places, some non-workers arbitrarily open the control cabinet to illuminate the tunnel lighting when they walk through the tunnel, and even use the wooden stick to hold the AC contactor to make the tunnel lighting always clear. In the long run, the waste of electricity is considerable.

In order to avoid the common phenomenon of tunnel lighting, the ideal lighting method is: the opening of the tunnel lighting is completely under the control of the railway patrol personnel, and the front lighting is gradually illuminated as the patrol personnel march; The lights can be automatically turned off after the person walks through; if necessary, the lighting time of a certain local area can be arbitrarily adjusted. In this way, energy can be saved, and the phenomenon of constant light caused by non-workers can be effectively prevented.

Due to its relatively low price and good color rendering index, sodium lamps have been widely used in railway tunnel lighting and road lighting. On the other hand, sodium lamps require a certain amount of ignition time. If it can only be turned on under the light at each time, due to the influence of the start-up time, the lighting will be weak. After the patrolman walks out a long distance, the brightness will be achieved. This kind of lighting is very uneconomical.

This paper introduces an inexpensive single-chip computer-based tunnel light intelligent controller. Each controller uses the serial communication port of the single-chip microcomputer to communicate with the adjacent controller to control the opening and closing of the tunnel light. Illumination mode operation can avoid the influence of the ignition time. The use of tunnel light intelligent controllers has two main advantages:
(1) It is easy to operate, saves energy, and avoids the installation of the tunnel light intelligent controller by the constant light. The patrol personnel can flexibly control the lighting condition according to the needs, and can turn on the light with the remote control transmitter in the vicinity of any tunnel light or Turn off the light and pass this command up or down. After issuing the short-open command, the patrol personnel can continue to travel to the position where the light needs to be turned on, and the subsequent lights are turned on, and the previously turned-on lights are automatically turned off.
(2) Effectively improve the use efficiency of the lighting lamp. The sodium lamp needs to reach a brightness of 100% after a certain ignition time. If only one light can be turned on under the light at a time, the lighting will be weak due to the influence of the ignition time, and the light will reach 100% brightness after the patrol person walks out a long distance. After the tunnel light intelligent controller is installed, when the patrolman sends a light-on command with the remote-controlled transmitter, a plurality of lights are turned on in front (including the position where the command is sent) (the number of opening can be specified in advance by the program as needed). The patrol personnel can open a number of xenon lamps in front of them according to their needs. This allows the patrol personnel to walk and work forever under the 100% brightness illumination of the sodium lamp, effectively avoiding the influence of the sodium lamp ignition time.

1. Composition of the controller <br> The intelligent controller of the tunnel light is composed of a remote control transmitter and a receiving controller (one remote control transmitter corresponds to multiple receiving controllers). The transmission of the remote command is completed by pressing the six keys on the remote control. The six keys are: short-open on the upstream (time-out after the open), on-off normally open, up-off, down-down, on-off, on-off . A remote control transmitter can be used to issue control commands in the vicinity of any of the tunnel lights. The function of the command is as follows:
(1) After the short-open receiving controller receives the short-open command (if the command can be accepted at this time), the light switch is turned on immediately. Under normal circumstances, the delay is automatically turned off after three minutes (the length of the delay time can be specified in advance by the program as needed). Since the sodium lamp cannot be turned on immediately after it is turned off, in any case, the receiving controller will not accept the command within one minute after turning off the light (the receiving controller can receive the command, beep, but not execute), only Accept the command again after a one-minute delay.
In addition, within three minutes of the short-open command being executed, the command can be issued again with the remote control transmitter. When the receiving controller receives the command, it replaces the previously received command with a new one.
(2) After the normally open receiving controller receives the normally open command (if the command can be accepted at this time), the light switch is turned on immediately and will not be extinguished. The remote command can also be accepted again after the normal opening, but no command will be accepted within one minute after the command is executed.
(3) After the closing command is issued, the light switch will be turned off to turn off the light.
(4) After receiving and accepting the above three commands, the receiving controller will automatically send the same command to the receiving controller of the subsequent (upstream or downstream) lamp to execute the command.

1.1 Remote Control Transmitter The remote control transmitter is mainly composed of SZ9148 chip. SZ9148 integrated circuit is made by CMOS technology and is a kind of infrared coded transmitting device with better performance. When the oscillator frequency is 455 kHz, its transmit carrier frequency is 38 kHz. Through the pins K1~K6 and T1~T3 on the chip, it can be connected into a 6×3 matrix keyboard, and the six buttons can be used to control the tunnel light.
The use of an infrared emitter not only has a large emission angle, is easy to control and is easy to operate, but also has a limited transmission distance and does not cause a control command to be received incorrectly due to reflection or refraction. The structure of the transmitter is shown in Figure 1.

Figure 1 remote control transmitter

1.2 Receive Controller Each receive controller consists mainly of a single AT89C52 single-chip computer. The receiving controllers of each tunnel light are connected in a serial manner to achieve illumination control of the entire tunnel. Therefore, there are three sources for receiving control commands: a remote control transmitter, an upstream direction reception controller, and a downstream direction reception controller.
For the reception of the remote transmitter control command, it consists of an infrared receiving circuit and a decoder (SZ9149 or SZ9150). The output of the decoder is connected to the single-chip microcomputer (AT89C52), and the single-chip microcomputer recognizes the control command, performs corresponding operations on the tunnel light, and sends a control command to the subsequent uplink or downlink receiving controller.
The adjacent receiving controller realizes the sending and receiving of the control command through the RS-232 serial communication interface, and the receiving controller receiving the control command performs the operation on the tunnel light by the single chip according to the control command, and determines whether to go to the subsequent uplink or The downlink receiving controller sends a control command. Since the AT89C52 has only one serial communication interface, an AT89C2051 microcontroller is used to implement another serial communication interface. The transfer of control commands between the two microcontrollers is implemented via a parallel port, as shown in Figure 2.

Figure 2 Receive Controller

1.3 Serial Communication Interface In order to make the serial communication interface between the receiving controllers conform to the RS-232 standard, the MAX232 chip can be used to convert the RS-232 and TTL levels, as shown in Figure 3.

Figure 3. Serial port connected to MAX232 chip

2. Program Design Points <br> The programming of the AT89C52 mainly includes three parts: command reception, command priority discrimination, and execution of priority commands and sending control commands to subsequent uplink or downlink receiving controllers. The command reception includes scanning of the decoder output and identification of the received command, receiving a command transmitted by the serial port, and a command transmitted by the parallel port.
The programming of the AT89C2051 consists of only two parts: the command to receive the serial port transmission is sent via the parallel port and the command transmitted by the parallel port is sent through the serial port.
The block diagram of the main program of the AT89C52 is shown in Figure 4.

3. Summary <br> Through the test, the tunnel light intelligent controller feels better, that is, it can conveniently control the switch of the tunnel light, effectively avoid the common light and avoid the inconvenience caused by the longer starting time. In practical applications, the serial communication method can also be changed to wireless transmission, which makes the construction more convenient. China has a vast territory and numerous mountainous areas. With the rapid development of railway construction, the number of tunnels will increase greatly. It is imperative to save electricity. The application of intelligent control of tunnel lights is broad.

main reference:
1. Sun Hanfang, Xu Aiqing, “The Principles and Applications of MCS51 Series Microcontrollers” Beijing University of Aeronautics and Astronautics Press, 1988
2, Li Hua "MCS51 series single-chip practical interface technology" Beijing University of Aeronautics and Astronautics Press 1993
3, Yu Yongquan "ATMEL 89 series FLASH single chip principle and application" Electronic Industry Press 1997

Achieving the Intelligent Control
For the Tunnel Illumination Based on Microcontroller
ZHU Yu ZHAO Tibo ZHOU Dingjiu
(China Academy of Railway Sciences, Beijing 100081)

Abstract:Tunnel lamp intelligent controller is a switch device designed for tunnel illumination. After installing the controller, the patrols could work under good illumination condition.
Key words:Tunnel illumination Intelligent controller

Figure 4. Schematic block diagram of the main program

Railway Research Institute of the Institute of Railways Contact:
010-51849685 Zhu Xi Zhao Bobo Bridge Building, Tiejian Institute, Railway Research Institute, No. 2, Daliushu Road, Haidian District, Beijing, China