The Application Of Hierarchy State Machine In Vehicl Navigation Play Control System

With the development of automobile industry, the vehicle navigation play control system is used by more and more vehicle enterprises. Vehicle navigation system and play control system are developed by Ri Tai company. With the improve of custom’s requirement, original play control software is often complained about the difficulty of the system maintainance and scalability. Hierarchy State Machine is a state machine based on a tree structure with a lot of system state nodes. The vehicle navigation play control system is designed and developed based on Hierarchy State Machine. The system maintainance and scalability are realized by adding, deleting or modifying the state nodes in state tree, which can greatly reduce the influence of system maintainance and improve the scalability of system.Firstly, the necessity of introducing Hierarchy State Machine Model in this area according to the insufficient of present play control system is defined. Based on that, the System Connection Management, Track Play Management and Track List Management are discussed, then the main operation flow of Peripheral Connection, Play Request and Track List Request are analyzed. Further more, the event-driven and hierarchical structure of the system is analyzed and the subsystem including Connection Control, Play Control and List Search are designed. Especially, attention is paid to the design and applying of Hierarchy State Machine in user play request and track list request key sub-systems. Finally, the differences between vehicle navigation play control system and other systems are discussed. The scalability is also analyzed.