A Study on the Design Method of the Real-Time System Software Based on RTOS

2014 ◽  
Vol 513-517 ◽  
pp. 2487-2491
Author(s):  
Dong Zhao ◽  
Shang Wei Jiang ◽  
Hong Wei Zhao ◽  
Xin Tong Yu

This paper combines the characteristics of real-time embedded systems and the real-time operating system to propose a software engineering method and process which bases on the function structured analysis and task structured design. First in the process of structured analysis based on the Hatley-Pirbhai method, extracting and sorting out the data flow and control flow according to the functional requirements of the system, analyzing and processing the functions of the system, the dependency among the functions and the timing sequence, and then realizing the design of the specific functions of the system, next achieving the structural design through the improving method, it also simplifies the system design processes. At this time, just need to analyze and divide the processing which is obtained from the structural analysis to get the specific task, design the interfaces among the tasks and also every task to get the new design method of the embedded real-time operating system, which also solves hard issue of the traditional method which is the weak extracting and developing iteration in the embedded real-time system.

Author(s):  
Sanjay Singh ◽  
Nishant Tripathi ◽  
Anil Kumar Chaudhary ◽  
Mahesh Kumar Singh

RTOS (real time operating system) can be defined as “The ability of the operating system to provide a required level of service in bounded response time.” A real time system responds in a (timely) predictable way to unpredictable external stimuli arrivals. To build a predictable system, all its components (hardware & software) should enable this requirement to be fulfilled. Traffic on a bus for example should take place in a way allowing all events to be managed within the prescribe time limit. However it should not be forgotten that a good RTOS is only is building block. Using it in a wrongly designed system may lead to a malfunctioning of the RT system. A good RTOS can be defined as one that has a bounded (predictable) behavior under all system load scenarios (simultaneous interrupts and thread execution). In RT system, each individual deadline should be met. Real-time systems are designed to control and monitor their environment. Most of these systems are using sensors to collect environment state and use actuators to change something.


2011 ◽  
Vol 268-270 ◽  
pp. 552-556
Author(s):  
Jian Jun Wu ◽  
Wei Wan ◽  
Da Hai Zhao

This paper introduces that embedded real time operating system μC/OS-II is applied in software design of aircraft electrical load management center. Firstly, the μC/OS-II and its running on ARM are briefly presented. Then the method of two system running modes is given in details. And the tasks assignment, priority allocation and communication between tasks under both two modes are also provided. Results show that multitask schedule managements of real-time system has solved the problem of poor real-time in a single task system. And the reliability of the system has been greatly improved.


1994 ◽  
Vol 158 ◽  
pp. 181-183
Author(s):  
R. A. Minard ◽  
A. J. Booth ◽  
W. J. Tango ◽  
T. Ten Brummelaar ◽  
H. Bennis ◽  
...  

The SUSI control system is a distributed real-time system currently consisting of 17 processors. A custom real-time operating system and network protocols ensure synchronous operation of servo loops across multiple processors.


2021 ◽  
Vol 2089 (1) ◽  
pp. 012022
Author(s):  
Ms Jayna Donga ◽  
M.S. Holia

Abstract Now a days numerous real-time OS like QNX, VxWorks, LynxOS and real-time extension of Linux practicing the processor affinity concept to schedule the real-time tasks and it offers more flexible approach instead of traditional approaches defined in the literature. Limiting the migration may reduce the context switch overhead and improve the cache performance but it largely influence on other parameters which are most important for the any real-time operating system. It degrades overall performance by decreasing the schedulability of tasks, increase the deadline miss ratio. This paper presents the problem in existing processor affinity based approach which confines the schedulability of the tasks and designed a novel processor affinity based algorithm to enhance the schedulability of the tasks and decreases the average deadline miss ratio by providing the flexible migration policy with the priority reassignment mechanism.


2021 ◽  
Vol 2066 (1) ◽  
pp. 012054
Author(s):  
Juan Xiao ◽  
Song Wang ◽  
Sheng Duan ◽  
Shanglin Li

Abstract Generally speaking, real-time system is considered to be able to influence the environment by receiving and processing data, and returning calculation results rapid enough, so as to control the environment. In computer science, real-time system describes the software and hardware system affected by time constraints, and its correctness relies on the logical correctness of the function and the time when the result is generated. According to the main characteristics of real-time operating system, such as time constraint, predictability and reliability, it puts forward higher requirements for the time accuracy and reliability of real-time operating system. This paper first introduces the real-time system from its main characteristics, related concepts and scheduling algorithm. Then five classical graph based task models of real-time system are introduced. Finally, this paper introduces the directed graph realtime task model from two aspects of definition and semantics. As an extension of realtime system task model, directed graph real-time task model is considered to be able to provide real-time systems with stronger expressive power and support the formal study of time constraint problems.


2015 ◽  
Vol 2 (1) ◽  
pp. 35-41
Author(s):  
Rivan Risdaryanto ◽  
Houtman P. Siregar ◽  
Dedy Loebis

The real-time system is now used on many fields, such as telecommunication, military, information system, evenmedical to get information quickly, on time and accurate. Needless to say, a real-time system will always considerthe performance time. In our application, we define the time target/deadline, so that the system should execute thewhole tasks under predefined deadline. However, if the system failed to finish the tasks, it will lead to fatal failure.In other words, if the system cannot be executed on time, it will affect the subsequent tasks. In this paper, wepropose a real-time system for sending data to find effectiveness and efficiency. Sending data process will beconstructed in MATLAB and sending data process has a time target as when data will send.


Author(s):  
Jörg Stöcklein ◽  
Daniel Baldin ◽  
Wolfgang Müller ◽  
Tao Xie

In our paper we present a virtual test environment for self-optimizing systems based on mutant based testing to validate user tasks of a real-time operating system. This allows the efficient validation of the code coverage of the test cases and therefore helps to detect errors in order to improving the reliability of the system software. Technically we are able to run and test the software on both systems. By writing application software and setting up the virtual test environment properly, we define our test cases. To validate the code coverage for our test cases, we use the approach of mutant based testing. By running this mutated code on our virtual prototype in the virtual test environment, we are able to efficiently validate the code coverage and are able to detect bugs in the application code or detect dead code that is not executed. Finding non-executing code leads to redefinition of our test cases by either changing the test environment or the application code in the case of dead code. We implemented the virtual test environment on top of the third party low cost VR system Unity 3D, which is frequently used in entertainment and education. We demonstrate our concepts by the example of our BeBot robot vehicles. The implementation is based on our self-optimizing real-time operating system ORCOS and we used the tool CERTITUDE(TM) for generating the mutations in our application code. Our BeBot virtual prototype in our virtual test environment implements the same low-level interface to the underlying hardware as the real BeBot. This allows a redirection of commands in ORCOS to either the real or the virtual BeBot in order to provide a VR based platform for early software development as well as ensures comparable conditions under both environments. Our example applies a virtual BeBot that drives through a labyrinth utilizing its IR sensors for navigation. The mutant based testing checks if all situations implemented by the software to navigate through the labyrinth are covered by our tests.


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