Ease: a real-time multitasking executive

Abstract

Ease the real time multitasking executive described m this thesis is designed for embedded systems with particular emphasis on DSP motor control applications. Ease provides an application software interface to the underlying hardware and encourages an object oriented programming approach which inherently enhances software integrity, maintainability and dependability in the potentially chaotic real time environment. Its focus is to tackle the undesirable aspects of real time programming and device dependent issues thereby allowing the application programmer to concentrate more on the application. The multitasking aspect of the executive means application tasks can be generated with ease which aids development, evolution or enhancement of an application. The multitasking aspect also facilitates tasks dedicated to on-line reconfiguration, error handling and fault correction or shutdown procedures. The software quality of a real time application running on the Ease platform is paid for by a small percentage of CPU processing power and a larger response time to external events than an unstructured monolithic interrupt driven system. During the course of research, development and prototyping of Ease , a number of suitable sample applications have been explored to test and optimise its functionality. The most notable of these is the control system for the motor simulation of a shock absorber with an active disturbance load. This was implemented as seven concurrent tasks in a uniprocessor DSP system, running Ease