Research Of Multitasking Embedded Real-Time Control System Software

With the rapid development of the digital information technology and network technology, embedded system has been widely used in various areas such as scientific research, engineering design, military technology, and so on. The traditional embedded system is designed to achieve a certain control function using simple control strategy. Following the increasing complexity and the extensive application of embedded system, more and more embedded system are required to realize the process of a variety of tasks including non-real-time tasks, soft real-time tasks and hard real-time tasks. However, it is difficult to meet real-time multitasking application request for the traditional single-threaded embedded system and multitasking time-sharing embedded system. In order to meet the needs of embedded system development, there is no doubt that the research on combined application of the embedded system and real-time multitasking system will further broaden.the application field of the embedded system.Taking this as background, a multitasking embedded real-time control system software is designed and developed to realize the seamless connection of Matlab/Simulink, based on the model based design method. It not only has embedded, multitasking, real-time, simple and quick second development characteristics, but also has high safety, reliability, maintainability and expansibility. There is no doubt that it will promote the future application and development of the embedded system to study, design and implement the system software. The main contributions of the dissertation are summarized as follows:1. Based on the analysis of research and development situation of real-time controllers and the real-time system at home and abroad, the dissertation summarize the advantages and disadvantages of the existing controller and present the design of the general structure of the multitasking embedded real-time control system software. To be specific, it consist of the design of the real-time kernel, real-time device driver and real-time monitoring program.2. The development and realization of the multitasking embedded real-time control system software are introduced in the paper in details. Specifically, it is comprised of the implementation of real-time kernel, real-time device driver and real-time monitor program. Respect to the real-time kernel, RTAI-Linux based on the double kernels mechanism is selected as the final real-time kernel after the research on the shortage and improvement scheme of Linux real-time performance. Besides, based on the analysis of LXRT mechanism, the implementation strategy of the real-time device driver is designed and presented. Finally, the real-time monitor program is developed detailedly on the basis of analyzing and using the RPC and MBX strategy. To meet the functional requirements, three functional modules are designed and developed which are respectively the control function module, the parameter display and modification function module and real-time data curve display function module.3. This paper completes the test of the multitasking embedded real-time control system software and its application validation to the double tank. Testing cases are developed first for real-time kernel, real-time device driver and real-time monitor program, respectively. And then, test results are obtained and show that each function unit works well and has good real-time performance. At last, the system software is applied to the double tank to validate the function and performance of the whole system software. Experimental results show that the multitasking embedded real-time control system software not only works well for each function unit, but only satisfies the request that real-time control system for speedy response, accurate time and divinable control in the environment of multiple tasks.