Design Of Vehicle Positioning Terminal In Power Recovery

To make up the technological and tactical weaknesses which exist in 95598 power recovery dispatching system and guarantee the dispatch recovery effectively and quickly in the power breakdown, according to the characteristics of the power recovery vehicle in field work, the distribution of electrical network infrastructure, this paper took advantage of global positioning technology and wireless network communication technology,proposed the design of"GPS+MCU+GSM", designed the vehicle terminal which is able to position the power recovery vehicles, it can enhance the response speed of power recovery request and reduce the time of resolving the fault.Under the guidance of hardware design principles in low power consumption, high stability and strong anti-interference ability, the main control unit selects enhanced low-power consumption microcontroller Atmega64L. GPS receiver uses specific car locator of SiRF Company with strong anti-interference and high sensitivity. GSM module uses HuaWei Company EM310 with low transmitting power and easy to update. To prevent the multi-path effect impact, EM310 uses anti-multipath antenna. As the voltage of car battery has wide dynamic range and large electromagnetic interference, the system adopts high efficient DC-DC regulators which manage the voltage of each module. The rechargeable lithium battery plays the role of a backup power. The LCD module with backlight has been designed to implement the human-machine interface. In addition, the vehicle anti-theft circuit has been introduced in this system. The high-frequency layout has been accomplished with the help of simulation based on the signal integrity analysis. It is able to prevent the system from being interfaced by the electromagnetic interference. As a result, the operation stability can be enhanced by this feature.In order to achieve precise positioning, we introduce the whole design. MCU unit uses the received GPS signal to analyze the latitude, longitude, speed, direction, time and other useful information about the vehicle. At the same time the AT order is being sent to connect the GSM module with the GPRS network. The packet data is sent to the internet server in the form of SMS via GPRS network. Due to the random time and variable length between the MCU and GPS, and between MCU and GSM, timing interrupts technology has been adopted in order to prevent the communication block and data loss. CRC has been used to enhance the dependability. Watchdog and auto reset function have been used to avoid the program running out.Finally, this paper introduces the debugging work of hardware and software in the way of using experimental methods to verify positioning accuracy. The results demonstrate that the vehicle terminal can achieve precise positioning capabilities. The terminal has excellent features such as small volume, easy installation, precise positioning, real time, low power, easy to upgrade. Our system has been deployed in the electric power recovery vehicles of subsidiary company. It promotes the process of power system information.