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GNSS and GSM-based embedded computers with CANBUS ability opened new areas of application in monitoring and controlling modern cars. The owners of these cars equipped with an on-board device with GNSS capabilities have the need for supervision of their property and some advanced comfort function like remote engine start up. This comfort function enables during cold winter days to start the engine remotely using the application and to warm the car up before entering it. Also using the application for smartphone to lock or unlock the car, or see its current location and past trips. The ability of such a system raises the security of the car and prevents grand theft. Additionally, it gives the owner the ability to remotely shut down the engine even if the driver possesses the car keys. On some car models, it is possible to completely replace the car keys with the smartphone application for easier everyday use. The owner doesn’t need to keep and carry the car keys as the smartphone replaces it. Additional options are possible like monitoring the car’s speed, engine’s RPM, controlling the car’s windows, opening the doors and trunk, etc. In this paper possible solution to control the car using on-board unit will be analysed. Several implementation difficulties due to complexity of car electronics and wiring will be examined. Proposed embedded system is based on the Atmel AVR family of processors, SIMCOM SIM908 GSM and GNSS system, Analog Devices ADXL343 3-axis Digital Accelerometer and Microchip MCP2515 Stand Alone CANBUS Controller. Previous version of the proposed system is used for monitoring and tracking of road vehicles in [1] and has real time software abilities. In this paper the system is upgraded with CANBUS controller so it can enable basic remote car control (engine start/stop, opening doors and windows) and advanced monitoring of all engine variables (temperature, RPM, fuel consumption). Boot-loader software is developed to allow remote modification of the embedded computer main program using the Hyper Text Terminal Protocol and GPRS communication network [2, 3]. Such approach enables faster software development. Main program is based and developed using a permanent GPRS state-full TCP/IP connection to the server, which analyses the GNSS and speed data received from embedded system and stores it in a database for additional off-line analysis [4]. Developed TCP/IP server is a socket daemon which enables multiple concurrent connections, tracking and message relaying for real time car remote control. Remote car control is enabled in the form of a smart phone application. Additionally, for older mobile phones the on-board device with GNSS capabilities has the user interface over short message service (SMS). It has the ability to connect to car’s central control system over CANBUS and various hard connection wire lines. Proposed system was tested in real world scenarios on many cars with different in-car electronics generation. Significant amount of GNSS position data was collected with some additional car information enabling off-line processing for high level tracking data analysis. |
