Research And Design Of Intelligent Dispatching Terminal Based On Embedded Linux

The number of civilian cars is increasing year by year, as a result, traffic congestion has become a restriction of the development of cities. Experience in other countries show that a good way to solve the problem is to develop the intelligent transportat ion, especially to develop the intelligent bus system. The Intelligent dispatching terminal is the hardware foundation of the intelligent bus system, The research of intelligent dispatching terminal can help to promote the performance of the intelligent bus system, such as the running efficiency and service quality, and contribute to the construction of city car networking. The increasing function of the intelligent dispatching system led to such great demand for multitasking capability and real- time performance that the traditional terminal has been unable to meet this requirement. So we need to design a new vehicle terminal with complete function, abundant peripheral interface and super real-time performance.In this paper, we firstly decided on the overall design scheme according to the function requirements of the intelligent dispatching system. We use the ARM Cortex-A8 and the Linux as the system of the intelligent dispatching terminal. Its high processing capacity and abundant peripheral interface can meet the requirements of intelligent dispatching multi- function, again through the transplant of embedded Linux operating system to implement multitasking and real-time requirements.Secondly, we had a study on the technology of the relevant technology involved by the intelligent dispatching terminal, especially the X264 bit-rate controlling technology. We optimized the X264 bit-rate control algorithm by changing the QP’s growth pattern in X264 frame layer rate and adjusting the growth mechanism of the buffer, and we also played an experiment, which showed that it not only can improve the bit rate control precision and also can reduce the image distortion.And then we introduced the design and implementation of the dispatching terminal software and hardware. Based on the function of the terminal, we selected the board of the dispatching terminal, completed the design of power supply module, display module and communication interface circuit for the terminal. On the basis o f the hardware design, we did the cutting, compilation and transplantation to embedded Linux, and completed a serial port communication, wireless network communication, and video monitoring application development, etc.Finally, the experimental research was conducted on the intelligent dispatching terminal. We tested the wireless network communication, remote video transmission and linkage of the terminal, and verified the multitasking capability, real- time and linkage with other automotive equipment capacity of the intelligent dispatching terminal.