Citation :

Azad Mohammed Shaik, "Freshness-Driven Scheduling: A Value-Aware Real- Time Framework for Sensor Fusion in Safety-Critical Systems," International Journal of Computer Science and Engineering, vol. 13, no. 4, pp. 31-50, 2026. Crossref, https://doi.org/10.14445/23488387/IJCSE-V13I4P103

Abstract

The traditional scheduling techniques used in real-time applications are generally centered around deadline compliance. However, they do not address the critical aspect of data freshness, which significantly impacts the quality and safety of the output from sensor fusion systems where temporal validity is essential. This paper proposes the use of a value-aware scheduling framework that includes an explicit data degradation model and allows for prioritization of tasks based on deadline urgency and temporal value. This framework introduces the following concepts: an exponential degradation model based on the sensors’ temporal validity windows, rejection of jobs that would produce stale data once completed, and dynamic priority assignment based on the sensor’s deadline urgency, time to fresh data, and criticality levels that conform to ISO 26262 safety standards. FDS was successfully implemented using FreeRTOS to evaluate the performance against an automotive sensor fusion application and was subjected to extremely high effective loads (303.6% and 415.6% demand scenarios). Performance results showed between 42–381% performance improvement over traditional fixed priority scheduling, and during the evaluation, no ASIL-D (Automotive Safety Integrity Level D - Highest Level of Safety Required by a Safety-Critical Application) deadlines were missed. Formal analysis provided guarantees of admitted jobs for all ASIL-D tasks, and evidence for an associated reduction in worst-case response times as a consequence of admission control interference. The work challenges the deadline-centric paradigm and shows that timely deadline completion does not guarantee retention of the temporal coherence of the output; rather, value-aware scheduling is required to provide temporal coherence.

Keywords

Real-Time Scheduling, Sensor Fusion, Data Freshness, Value-Aware Scheduling, Mixed-Criticality Systems, Age of Information, FreeRTOS, Safety-Critical Systems, ISO 26262.

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