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In recent years, with the rapid development of the economy and the continuous deepening of urbanization, higher requirements have been put forward for corresponding municipal supporting facilities. As a public infrastructure of modern cities, street lights play an important role in the daily operation of cities and people's lives. The advanced level of street light control system signifies the modernization level of a city. At present, the world is facing an energy crisis, and electricity resources have become a scarce resource. There is a serious waste of electricity resources in our country, so energy conservation and consumption reduction are policies that need to be vigorously promoted. At present, many urban street light systems can only achieve the function of turning on and off lights on time, and only control the street lights according to the set time. The use of all night lighting has caused a lot of waste of electrical resources. With the increasing number of motor vehicles and the development of population density, traditional urban street lighting systems have also shown many other shortcomings and shortcomings. For example, in rainstorm weather, the sky is dark even in the daytime, but it lacks necessary road lighting; At night and with low pedestrian and vehicular traffic, street lights are illuminated all night, resulting in a certain degree of power waste; In addition, if the street light malfunctions, it can only be detected through inspection by the street light inspector and cannot be promptly reflected in the lighting control system, which brings inconvenience to maintenance work. Therefore, it is necessary to establish an intelligent street light control system with multiple working modes.
The rapid development of technologies such as microcontrollers, 1C chips, and sensors has provided a prerequisite and foundation for the development of intelligent street light control and illumination fuzzy control systems. The adoption of an intelligent street light control system can not only meet the normal road lighting functions, but also effectively save power resources, making the urban street light system more scientific and humane. At the same time, it also improves the efficiency of maintenance and repair of the street light system, and to some extent reduces the labor intensity of municipal workers.
The intelligent street light control system designed in this article not only has the basic function of turning on and off the lights on time, but also can flexibly set the working mode according to the actual needs of road traffic, thereby achieving automatic control of the opening and closing of the street lights, in order to achieve maximum energy conservation. In addition, if the street light malfunctions, the system can automatically alarm and communicate to the control center in a timely manner.
The hardware structure of the intelligent street light control system is shown in Figure 1. The system uses AT89S52 as the main control module, DS1302 as the clock module, photoelectric switch H22A2 as the infrared sensing module, photoresistor as the metering module, LCD1602 LCD as the display module, and communication chip MAX232 as the communication module. In addition, the system also includes a fault detection module, keyboard module, and alarm module.
2. Hardware Circuit Design 21. The keyboard module is connected to the microcontroller P1.0, P1.1, P1.2, P1.3, and P1.4, respectively. In the initial state, press button K1 to enter the working mode at the alley entrance, press button K2 to enter the timed working mode, and press button K3 to enter the road working mode. Exit the current working mode by pressing the K5 button. In the timed working mode, first set the hour, minute, and second of the DS1302 clock chip using buttons K1, K2, and K3, which are determined by K4. Then, set the year, month, and day of the DS1302 clock chip using buttons K1, K2, and K3, which are determined by K4, in order to modify the time and timing settings of the DS1302 clock chip.
2.2 Photometric module photoresistor, also known as light guide, has the characteristic of rapidly reducing its resistance under light irradiation, and can be used to detect visible light. The light detection circuit is shown as follows. NE555 forms a comparator and uses the switching characteristics of the transistor to convert the signal into a square wave. Its output end is connected to the P1 of the microcontroller 7-port connection. When the ambient light intensity exceeds the set value, the resistance of the photoresistor only decreases, NE555 outputs a low level, the transistor is turned off, the LED indicator light is off, and the light detection circuit is turned to P1 7-port output high level, control system does not start working mode; When the ambient light intensity is lower than the set value, the resistance of the photosensitive resistor g1 increases, NE555 outputs a high level, the transistor conducts, the LED indicator lights up, the light detection circuit 7 outputs a low level, and the control system starts the set work. 2.3 The infrared sensing module infrared sensing circuit is shown in. When the system operates in the alley mode, the infrared sensor H22A2 is used to detect the passage of pedestrians and vehicles, and the infrared sensors are placed along the road in the order shown in a-c. When someone or a vehicle passes through infrared sensor 1, the sensor outputs a high level, and the microcontroller adds 1 to the corresponding count value of infrared sensor 1 for counting; When someone or a car passes through infrared sensor 2, the sensor outputs a high level, and the microcontroller adds 1 to the corresponding count value of sensor 2, while subtracting 1 from the corresponding count value of sensor 1; When someone or a car passes through infrared sensor 3, the sensor outputs a high level. The microcontroller adds 1 to the corresponding count value of sensor 3 and subtracts 1 from the corresponding count value of sensor 2; When the count value corresponding to the infrared sensor is not 0, the street light control circuit will turn on the street light corresponding to the sensor; When the count value corresponding to the infrared sensor is 0, the street light control circuit will turn off the street light corresponding to the infrared sensor.
2.4 Fault detection module: Install a fault detection circuit next to each street lamp (the same as the light detection circuit). Compare the output of the fault detection module to the microcontroller P3 The signal from port 4 and the signal output from the light detection circuit to port P1.7 of the microcontroller. If the high and low levels of the two signals are different, the microcontroller will activate the alarm module to send an alarm signal and transmit the fault information to the control center through the communication interface.
The street light control module and alarm module are mainly composed of relay circuits. When P0.4 outputs high voltage, the transistor Q3 is cut off, and the relay does not work, that is, the street light control module remains in a closed state; When P0.4 outputs low voltage, the transistor Q3 conducts, the relay operates, and the street light control module enters the on state alarm circuit using an audible alarm method. When the street light malfunctions, the microcontroller outputs a high level at port 3, causing the transistor in the circuit to conduct and the buzzer to sound; When there is no fault with the street lights, the microcontroller P0 3-port output low level, alarm circuit not working.
2.6 Clock Module DS1302 is a high-precision clock integrated circuit that can perform year, month, day, week, hour, minute, and second timing, with powerful functions. The clock module circuit uses the DS1302 clock chip to provide the clock signal required for timing on/off light operation for the system, and the clock data can be adjusted through the keyboard control module.
2.7 Display Module The display module adopts LCD LCD1602. In initialization mode, the LCD screen will display Choosemode: 1. IR; 2. TM; 3. SM corresponds to 1. Lane exit mode;. Timed mode;. "Road mode" can be selected by pressing the button according to actual needs. When entering "1. Alley mode" and "Road mode", the LCD screen will display "Choose T Mode" based on the high and low levels output from the light detection circuit. AI; 2. al; 3. On; 4. tw, respectively representing 1. Set the current time; 2. Display the timing switch time of two lights; 3. Set the individual on/off time for the first light; 4. Set the time for the second light to be timed separately, which can be selected by pressing the key. In the four T-Mode modes, the first line displays January 1st of the year, and the second line displays the hour by minute, and the time can be adjusted and set through the keyboard.
The MAX232 serial communication circuit is used in the 2.8 communication module system. Due to the fact that the RS232 level of the computer serial port is 10+10V, while the signal voltage of a typical microcontroller application system is TTL level 0+5V, MAX232 is used for level conversion to achieve communication between microcontrollers and computers. The communication circuit is shown in.
The intelligent street light control system is designed using the AT89S51 microcontroller as the core control system, and the system functions are achieved through programming. The main program flow communication circuit is shown in. At the beginning of the program, the microcontroller is first initialized, and then the intelligent street light working mode is selected. At the same time, fault detection is carried out after each execution of the street light control module. When the light detection circuit in the system malfunctions, the buzzer will sound an alarm, and the number of the faulty light will be displayed on the LCD LCD1602; When there is no fault, start normal operation. If the light intensity is weak or the timed light on time is up, call the street light control subsystem. Otherwise, continue to judge.
In the process of system software design, attention should be paid to some design details in the main program flow, such as whether the software stabilization part of the button module is correct and effective; Is the response time in flow detection and control short enough? If the delay time is too long, it will result in ineffective operation of increasing the brightness of the street lights only after the flow of people and vehicles passes by; In the anti-interference program design of photosensitive devices, multiple discriminant confirmations are adopted, and appropriate delays are given between two discriminants to ensure the detection of correct and effective signals.
Conclusion 4: The system has implemented multiple working modes, which can not only independently set and display the on/off time of the lights, but also automatically determine whether to activate the set working mode based on changes in ambient light brightness. It also uses infrared detection technology to effectively achieve the functions of turning on and off the incoming and outgoing lights. The working mode of the entire system can be flexibly selected according to actual needs, with stable performance, simple and convenient operation, low system cost, and high reliability. This system has the advantages of multiple working mode choices and reducing electricity consumption, and has certain practical significance. |
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