Real-time Embedded Software Research Articles

Timing consistency checking for UML/MARTE behavioral models

UML/MARTE model-driven development approaches are gaining attention in developing real-time embedded software (RTES). UML behavioral models with MARTE annotations are used to describe timing behavi...

Embedded Software Formalization Testing Method and its Application in Missile-Borne Software

The formal modeling method can accurately describe systems. Using formal method to test software improves the efficiency of software testing and it is comprehensive. Common real-time embedded software formal testing methods include Z language, finite state machine (FSM) and unified modeling language (UML), Petri net and time input/output automata (TIOA). This paper analyzes the characteristics of embedded software testing. The above formal methods and test case coverage criterions and test data collection methods are introduced. Combined with the characteristics of missile-borne software, this paper presents suitable ideas of testing missile-borne software.

Real-time embedded software testing method based on extended finite state machine

The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded system, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine (RT-EFSM) model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class (timeCTEC) are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics realtime embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.

The Integrated Application Based on Real-time Extended UML and Improved Formal Method in Real-time Embedded Software Testing

In this paper, formal methods were introduced into the real-time embedded software testing field and a real-time extended finite state machine, called rt_EFSM, was studied firstly. And then, the process of the integrated application based on real-time extended Unified Modeling Language (UML) and improved formal method in real-time embedded software testing are put forward. Furthermore, the extension scheme of the real-time UML, including the improvement and extension of state transitions and time constraints described mechanism, and the conversion method from real-time UML to rt_EFSM ware proposed. Finally, combined with the testing process of flight control software of an unmanned aerial vehicle (UAV), a method to generate the time-extended UIO sequence (ex_UIO) was put forward. Finally, the method to generate test cases automatically according to ex_UIO sequence was brought forward. The method proposed in this paper can fully make use of the advantages of tool resources of the UML which has been as the industry standard, but also the advantages of formal methods in accuracy, effectiveness and automation support.

Design and Application of Real-Time Embedded Software Simulation Testing Object Framework

At present, the automated real-time embedded software testing is a hot topic. Automated testing is essentially based on user programming and how to build test script quickly and effectively is one of the key problems to be resolved. In this paper, the object-oriented and framework technologies are introduced into the real-time embedded software testing field and the real-time testing object framework (RT-TOF) is studied firstly. And then, the test script generation process based on RT-TOF is proposed. Furthermore, the design of RT-TOF is put forward. Finally, the test script sample of the avionics embedded software system testing is given. Practical application of RT-TOF in engineering shows that the method proposed in this paper can improve the efficiency of automated testing greatly and the test script based on RT-TOF has better maintainability and reusability.

Remultiplexing Eureka-147 Ensemble With MPEG-2 TS for T-DMB Multimedia Service

This paper introduces a layered structure of the Korean terrestrial digital multimedia broadcasting (T-DMB) ensemble based on Eureka-147 and suggests a new transmission architecture for flexible T-DMB service. In the suggested transmission architecture, MPEG-2 transport stream (TS) for T-DMB multimedia service is inserted into the ensemble distributed via the ensemble transport interface (ETI). Thus, we propose a novel algorithm remultiplexing the ETI with MPEG-2 TS. The architecture of ETI remultiplexing algorithm is described as a four-step process, and implemented as real-time embedded software in an ETI remultiplexing system. The design and implementation of the interoperable ETI remultiplexing system available for a small-scale transmission system for T-DMB service is described in detail.

A course in real-time embedded software

Embedded systems are increasingly pervasive, and the creation of reliable controlling software offers unique challenges. Embedded software must interact directly with hardware, it must respond to events in a time-critical fashion, and it typically employs concurrency to meet response time requirements. This paper describes an innovative course that gives students in-depth exposure to the challenges of writing reliable, time-critical, concurrent code. Students design and implement a real-time operating system (RTOS), and they write application code that uses the RTOS they construct. Code development and debugging take place in a simulation environment that offers visibility into the system and strictly repeatable execution while maintaining hardware compatibility. We describe the structure of the class, the custom tools used, and the laboratory sequence that results in a functional RTOS. We discuss the development of the class and its impact on our students.

Architecture description languages for high-integrity real-time systems

Safety-critical systems, such as those in the avionics, automotive, power, space, and medical industries, are predominantly driven by real-time embedded software and are often referred to as high-integrity real-time systems (HIRTS). In these systems, safety is of paramount importance. Safety is broadly defined as freedom from accidents and loss. When no safe alternative to normal service exists, a system must be dependable to be safe, that is, it must have reliable ways to deliver a certain quality of service. Our collaborations with industrial partners have focused on HIRTS modeling techniques. Initially, we explored the potential benefits that the most successful software architecture and modeling approaches could bring to the safety-critical domain. We subsequently designed the architecture information modeling language. AIM lets us exploit the available technologies from the same platform and thus provide stronger support for the safety case. A safety case, a key element in HIRTS certification, typically consists of a high-level argument and supporting evidence. The HLA sets the principles on which the design is based and reasons why the design should satisfy the safety requirements.

Formal verification of real-time embedded software in an object-oriented application framework

With the rapid escalation in design complexity of real-time embedded software, application frameworks have become an almost indispensable tool because they greatly ease the work of a designer by performing tedious tasks on behalf of a designer and by reusing semi-complete application codes. To ensure code quality and reliability, computer-aided analysis is also performed for the generated application software in some frameworks. However, when the target is real-time embedded systems, the correctness of the software in terms of satisfying all user-given real-time and embedded constraints becomes a primary objective for such frameworks. To guarantee correctness, formal verification in the form of model checking is a viable solution due to its full automation capability. Nevertheless, little is known from either the existing literature or industrial experience on how formal verification can be integrated into an object-oriented application framework, whose primary purpose was previously only to design and generate application software. This work contributes to the state-of-art technology by showing how a design framework and a verification framework can be integrated. Three main issues are tackled: (i) what to verify?; (ii) when to verify?; and (iii) how to verify? As a solution to these three issues the authors propose a mapping from the object-oriented model to a formal model, a schedule-verify-map strategy and a compositional verification methodology, respectively. These have been implemented in a component-based framework and experiments performed to illustrate their feasibility. Due to the incorporation of industry de-facto standards such as real-time unified modelling language and real-time Java, in the proposed techniques it should now be possible for an engineer to gain access to theoretically proven formal verification technologies that would otherwise be considered to be inaccessible to an engineer unskilled in verification techniques.

Compiler test case generation methods: a survey and assessment

Software testing is an important and critical phase of the application software development life cycle. Testing is a time consuming and costly stage that requires a high degree of ingenuity. In the development stages of safety-critical and dependable computer software such as language compilers and real-time embedded software, testing activities consume about 50% of the project time. In this work we address the area of compiler testing. The aim of compiler testing is to verify that the compiler implementation conforms to its specifications, which is to generate an object code that faithfully corresponds to the language semantic and syntax as specified in the language documentation. A compiler should be carefully verified before its release, since it has to be used by many users. Finding an optimal and complete test suite that can be used in the testing process is often an exhaustive task. Various methods have been proposed for the generation of compiler test cases. Many papers have been published on testing compilers, most of which address classical programming languages. In this paper, we assess and compare various compiler testing techniques with respect to some selected criteria and also propose some new research directions in compiler testing of modem programming languages.