Acoustic Communication In Real-time Embedded Software Design

Along with increasing exploitation of marine resources, the studying of underwater robots has become a worldwide hot spot. And communication between these robots is one of the key technologies in the development of underwater robots. In this paper, the main task is to design an underwater robots communication system software to implement communication between shore-based or other nodes and the underwater robots, make it possible to send commands to the robots or receive running information returned from the robots. According to the requirements of multi-task, real-time and reliability in underwater communication, a scheme of PC104 platform combined with real-time embedded operating system VxWorks is identified.Firstly, the device driver under VxWorks is analyzed. Then the driver for collecting and sending audio data which accords with the AC'97 standard is developed considering the given features of I/O system drivers and interrupt handling.Subsequently, tasks and communication mechanism of VxWorks system are studied. To meet the multi-state and multi-task requirements, according to the half duplex working mode, a communication software is designed, in which some performances are made sure such as multi-task transferring and high real-time.Next, serial and network communications in VxWorks system is studied. For the acoustic communication system, serial communication with robots control system is realized as well as the network communication and start-up control functions with the shore-based control software based on the need of robots control interface and field trials.Finally, Visual C + + 6.0 and MFC are used to complete the design of shore-based test control software. The testing results show that the communication between serial port of the control software and network is effective. In addition, the system is operating steadily and is flexible, and design requirements are met.