Learn More
Many sensor-based control systems are dynamically changing, and thus require a flexible scheduler. The rate monotonic (RM) real-time scheduling algorithm does not support such dynamic systems very well. On the other hand, with earliest-deadline-first (EDF) and minimum-laxity-first (MLF) dynamic scheduling algorithms, a transient overload in the system may(More)
—The port-based object is a new software abstraction for designing and implementing dynamically reconfigurable real-time software. It forms the basis of a programming model that uses domain-specific elemental units to provide specific, yet flexible, guidelines to control engineers for creating and integrating software components. We use a port-based object(More)
This paper describes the Chimera II Real-time Operating System, which has been developed for advanced sensor-based control applications. It has been designed as a local operating system, to be used in conjunction with a global operating system. It executes on one or more single board computers in a VMEbus-based system. Advanced sensor-based control systems(More)
This study focuses on the current state of error-handling technology and concludes with recommendations for further research in error handling for component-based real-time software. With real-time programs growing in size and complexity, the quality and cost of developing and maintaining them are still deep concerns to embedded software industries.(More)
This paper presents a time division multiple access medium access control protocol for wireless sensor / actuator networks implemented with a contention-free message scheduler. A message scheduler is used to determine which message has access to the medium at any time. A set of messages is contention-free if only one message is ready at a time. Otherwise,(More)
ily based on knowing worst-case execution times (WCET) of periodic threads and aperiodic servers. Accurately measuring WCET, however, is often difficult and sometimes impossible, for several reasons: • Interrupts in the system, which either execute longer than expected or occur more frequently than anticipated , may steal critical execution time from the(More)
The Chimera Methodology is a software engineering paradigm that enables rapid development of real-time applications through use of dynamically reconfigurable and reusable software. It is targeted towards a distributed shared memory computing environment. The primary contribution of this research is the port-based object model of a real-time software(More)
—This paper describes a computer-aided software engineering (CASE) tool that helps designers analyze and fine-tune the timing properties of their embedded real-time software. Existing CASE tools focus on the software specification and design of embedded systems. However, they provide little, if any, support after the software has been implemented. Even if(More)
The development of software for reconfigurable sensor-based real-time systems is a complicated and tedious process, requiring highly specialized skills in real-time systems programming. The total development time can be reduced by automatically integrating reus-able software modules to create applications. The integration of these modules can be further(More)