Real-time Kernel Support for Engine Control Applications

Engine control applications typically include computational activities consisting of periodic tasks, activated by timers, and engine-triggered tasks, activated at specific angular positions of the crankshaft. Such tasks are typically managed by a OSEK-compliant real-time kernel using a fixed-priority scheduler, as specified in the AUTOSAR standard adopted by most automotive industries. Recent theoretical results, however, have highlighted significant limitations of fixed-priority scheduling in managing engine-triggered tasks that could be solved by a dynamic scheduling policy. This master thesis proposes a new kernel implementation within the ERIKA Enterprise operating system, providing EDF scheduling for both periodic and engine-triggered tasks. The proposed kernel has been conceived to have an API similar to the AUTOSAR/OSEK standard one, limiting the effort needed to use the new kernel with an existing legacy application. A simulation framework is presented, showing a powerful environment for studying the execution of tasks under the proposed kernel. Such framework is based on Lauterbach Trace32 Cortex simulator and it was extended with custom plugins for testing the proposed kernel. Performance tests are designed and executed in order to evaluate the proposed kernel in terms of run-time overhead and footprint, that represent the main drawbacks of the earliest deadline first kernel with respect to the fixed-priority scheduling. The thesis is organized as follows: the first chapter is an introduction about the engine control and related problems; then a related works and studies are presented, moreover the theoretical model of the engine control is reported. The second chapter shows the system architecture, with a description of the software tools and hardware devices adopted. Chapter four describes the design of the simulation framework with a special attention to the developed plugins, needed for simulating the proposed kernel. Then the experimental environment and result are shown and discussed