Embedded Control Software Design Research Articles

A real-time operating system supporting distributed shared memory for embedded control systems

The paper presents a real-time operating system (RTOS) that provides a distributed shared memory (DSM) service for distributed embedded control systems. Model-based design is widely adopted in embedded control software design and the source code of software modules can be generated from a controller model. The generated software modules exchange their input and output values through shared variables. We develop a RTOS with a DSM service to provide a location-transparent environment, in which distributed software modules can exchange input and output values through the DSM. The RTOS is an extension to OSEK OS. We use a real-time network called FlexRay, which is based on a time division multiple access (TDMA) protocol. The consistency of the DSM is maintained according to the order of data transfer through FlexRay, not using inter-node synchronization. The worst case response time of the DSM is predictable if the FlexRay communication is well configured.

Embedded control software design with aspect patterns

This article presents an aspect-oriented design method for embedded control software. Model-based control design has become popular in embedded control systems such as automotive control systems. In the control logic design phase, a control model is built with a CAD/CAE tool such as MATLAB/Simulink, in which ‘zero-time execution’ is assumed. Then, in the software design phase, we design the software to meet timing constraints and to execute control logic correctly in the preemptive multi-task environment. We design task structures and then add mechanisms for data integrity. To make the timing design more efficient, we represent the mechanisms for the timing design as reusable aspect patterns. We define aspect patterns of triggering methods, synchronizations, and inter-task communications. We also provide a model weaver to weave the aspect patterns into the base model incrementally. In the timing design, we only have to select the aspect patterns and weave them into the functional model with the model weaver.