Identifying safety issues from energy conservation requirements

Abstract

In cyber-physical systems such as robots and automated vehicles that rely heavily on batteries, safety, and energy conservation can result conflicting requirements when not considered together. In systems engineering, the development begins at a concept phase where we have high-level information of different components of the system. During the concept phase, we perform hazard analysis and risk assessment, define safety goals, and derive safety requirements. This means requirement engineering occurs at the end of the concept phase. However, energy conservation recommendations are not taken into consideration until the detailed design with specific hardware and software is known. Hence, it is possible to recommend energy conservation behaviors that can compromise system's safety. If we perform a trade-off analysis between safety and energy conservation at a concept phase, we can propose various design alternatives and choose the best one that offers a safe and energy saving architecture. To achieve this goal, we propose an approach for identifying safety issues that can be caused by energy conservation recommendations. To evaluate the effectiveness of our approach, we performed an empirical study on four robotic systems. Our results show that we can find energy conservation recommendations that can compromise safety at a concept phase.

A Brief Review of Systematic Risk Analysis Techniques of Lithium-Ion Batteries

“…STPA is a top-down analysis tool developed from systems theoretic accident modelling and process (STAMP) (Sulaman et al, 2019). The unsafe interaction between system components is emphasized by structuring the control loop (Madala, Do, andTenbergen, 2022, Rausand andHaugen, 2020). STAMP shifts the purpose from avoiding failures to enforcing safety control action (Rosewater and Williams, 2015), providing a new perspective to think about battery safety.…”