In this paper, the software LabView and NI ELVIS are used as the development platform for the design of traffic signal controller. The design of hardware circuit and software programming are completed.
Finally, the control requirements of traffic signal controller are realized through debugging of software and hardware system. Traffic plays an important role in people’s daily life. With the development of economy and social progress, traffic must be effectively controlled. Traffic signals can be used to guide traffic flow, improve road capacity and reduce traffic accidents.
This design can also be applied to daily teaching, combining theory with practice teaching, can improve students’interest in learning, and can also establish a good foundation for the follow-up courses.
Using LabView and NI ELVIS to design can give students perceptual and intuitive understanding to inspire students’innovative thinking. LabView is a program development environment developed by NI.
It uses graphical editing language and produces programs in the form of block diagrams. LabView software is an ideal choice for developing measurement and control system. NI ELVIS can be used for hands-on design and prototype design. The platform integrates 12 most commonly used instruments, including oscilloscope, digital multimeter, function generator, thermostatic element Porter analyzer, etc. The compact structure is the ideal choice for laboratory and classroom teaching.
NI ELVIS can connect with PC through USB interface to realize fast and easy-to-use measurement acquisition and display. The design of NIELVIS aims at teaching and is a comprehensive teaching tool for circuit design, instrument control, wireless communication, embedded/MCU theory and so on. An intelligent traffic light controller is designed, which can realize the automatic command of traffic lights and dredge traffic flow.
Secondary state 4: When the green light is off at the East-West intersection and the yellow light is on for 5 seconds, switch to the second state 1 again for repetition. The time of red, yellow and green traffic lights on and off can be adjusted. It has countdown function. Design analysis. According to the analysis of control requirements, the time sequence diagram of traffic signal control is given, and the intersection of two channels is defined. The four time periods are T1, T2, T3 and T4, respectively. Calculate the 8-bit code sent to the digital port in four time periods to control the lights on and off.
For example, the corresponding north-south red, yellow and green lights in the T1 cycle are 0001, and the east-west direction is 0100. Then the 8-bit codes in the T1 cycle are converted from the high-bit to the low-bit binary codes, and the decimal codes are 20. By analogy, the corresponding codes of T2, T3 and T4 can be determined. Hardware wiring. The hardware circuit is built on the NI ELVIS prototype design board, as shown in Figure 1. Software design.
Using LabView software for image programming, part of the program block diagram is shown in Figure 2, and the front panel is shown in Figure 3.
In this paper, a traffic signal controller is designed by combining LabView, NI ELVISw and electronic components. After debugging of the hardware and software system, the control requirements are fully realized.
The time can be adjusted, so it can be applied to real life.