Zero-Jitter Chains of Periodic LET Tasks via Algebraic Rings

• Published in: IEEE transactions on computers Vol. 72; no. 11; pp. 1 - 14
• Main Authors: Bini, Enrico, Pazzaglia, Paolo, Maggio, Martina
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-11-2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Automobile industry; automotive; Automotive engineering; Behavioral sciences; Computational modeling; Control Engineering; Electrical Engineering, Electronic Engineering, Information Engineering; Elektroteknik och elektronik; embedded software; Engineering and Technology; Jitter; LET; Logical execution time; Real-time systems; Reglerteknik; Rings (mathematics); Task analysis; task chains; Task complexity; Teknik; Vibration
• ISSN: 0018-9340; 1557-9956
• DOI: 10.1109/TC.2023.3283707

In embedded computing domains, including the automotive industry, complex functionalities are split across multiple tasks that form task chains . These tasks are functionally dependent and communicate partial computations through shared memory slots based on the Logical Execution Time (LET) paradigm. This paper introduces a model that captures the behavior of a producer-consumer pair of tasks in a chain, characterizing the timing of reading and writing events. Using ring algebra, the combined behavior of the pair can be modeled as a single periodic task. The paper also presents a lightweight mechanism to eliminate jitter in an entire chain of any size, resulting in a single periodic LET task with zero jitter. All presented methods are available in a public repository.