Intelligent Parking Guidance System Based On WSN

The prevailing question of city Parking lot is difficult for drivers to find an available carport and get in and out of the lot, which has a serious impact on the operating efficiency and the service level of the lot. The establishment of the intelligent guiding system can help the drivers get an accurate perception whether the carport in the parking lot is used or not, then guide them to complete the parking procedure quickly and efficiently. As a result, the system is of significance in enhancing the operating efficiency of the park lot and the utilization rate of parking spaces.The paper completed the research and the implementation of the intelligent guiding system in the parking lot based on the wireless sense network. The system can be divided into two parts, including the wireless sensing subsystem and the parking management platform subsystem. Firstly, the parking lot can be mapped to a rectangular maze model. On the basis of the model, the paper proposed a carport route searching strategy in the parking lot, which can lead the drivers to find the nearest carport and program the shortest route to the carport through the flooding processing on the carport information in the model. Then, a sensor network data acquisition strategy based on the polling cycle was designed to achieve reliability and low-power wireless transmission of the status data in the parking lot, which can distribute the time data to control the polling cycle with a strategy based on flood routing that called sensor network time data distribution mechanism and collect the status data of the parking lot with a strategy based on aggregation routing that called sensor network status data collection mechanism. Finally, the parking management platform was established based on the ThinkServer TS540 and the wireless sense subsystem was established using the ATmega1281 micro programming chip, At86RF230 RF chip and the ultrasonic sensor. Through the software and the hardware integration of the two subsystems, the functional tests and the performance analysis on the system were completed.The test result showed that the system can enable wireless acquisition and reliable transmission of status data in the parking lot, under the condition of polling frequency with 0.1HZ and duty cycle with 20%, data loss rate of effective sensor nodes gets close to zero. In the aspect of energy consumption, the working time that the sensor nodes applied to ensure reliable transmission with low packet loss rate only takes 5% of the polling cycle, which can effectively extend the lifetime of wireless sensor subsystem. In terms of precision guidance, the drivers can be directed to the designated parking spaces, and the system can provide services in three situations: admission guidance, repeat guidance and exit guidance, thus the system can meet the actual demands of intelligent guidance in the parking lot.