The current issues related to global warming have led to significant changes in behavior. Driven primarily by governments, many industries have had to revise their strategies in favor of a greener environment. This is also an opportunity for others to highlight their technology to protect an environment damaged by climate change.
The use of new technologies is one of the keys in response to these new challenges: electricity as a less polluting energy source or drones for monitoring the increasing number of wildfires caused by rising temperatures are examples of innovations that have seen significant growth in recent years.
The downside of this transformation is the introduction of new risks associated with the technologies used, which must be managed for the safe use of the new solutions being offered.
Functional Safety approaches, governed by functional safety standards, help contain these risks at acceptable levels through the implementation of safety-instrumented systems.
The rest of this article presents their contribution in risk management for several application cases. The first is the use of “clean” energy sources for different types of vehicles. The second is the use of drones for wildfire monitoring.
State of the Art: Issues and Safety Standards for New Technologies
The issue of managing functional risks related to the use of these new solutions is a key factor in the success of technological transformation.
Functional safety standards such as ISO 26262, ISO 25119, etc., when established for the relevant domain, help address this need by managing the risks associated with the use of electrical and electronic systems within new technologies. The approaches proposed by these standards translate into the implementation of safety-instrumented systems designed to secure the system in the event of detecting a dangerous failure, developed within a strict framework to prevent the introduction of systematic failures (such as design or implementation faults).
The use of new energy sources in vehicles, such as lithium batteries or fuel cells, to reduce greenhouse gas emissions, requires specific electronic management within the vehicles to convert the energy into electricity, which may pose risks to users.
Certain sectors, such as the automotive industry, are no strangers to managing risks related to vehicle electrification with high-voltage batteries. With a few years of experience with the technology, the state of the art in covering the risk of fire involves battery cell monitoring. Similarly, the technical solution for securing against electric shock risk involves opening the electrical circuit. All of this is developed under the ISO 26262 functional safety standard.
However, this is not the case for charging stations, installed in private garages, where the main risks (fire and electric shock) are the same, yet they are not subject to any specific functional safety standards.
The same situation applies to other sectors that have recently faced new risks related to the use of CO2-free energy sources. For example, new generations of shared bikes now offer electric assistance (Electric Assisted Bicycles – EAB) for more “green” commuting. The electrification of EABs requires a charging station, which presents a potential electric shock risk. Unlike EABs, which are regulated by the product standard EN 15194, requiring the implementation of safety functions to mitigate fire risks or unintended assistance risks, according to development with ISO 13849, charging stations are not subject to any functional safety standards.
The aviation sector is also impacted by this change in energy sources, as discussions that began a few years ago to electrify aircraft have now been technologically validated and are moving into the development stage. With hydrogen-powered fuel cells generating electricity, the first “clean” aircraft could be developed by 2035. The introduction of this new energy source means high voltage, requiring additional insulation efforts for all electronic equipment. The risks associated with the fuel cell lead to considerations of higher external stress levels than what is typically addressed in the sector, which is studied by functional safety analyses usually deployed in the industry (DO178, DO254, ARP4761, ARP4754).
Electrification is also touching the agricultural sector, as machinery used for soil work or seeding is also starting to electrify. The ISO 25119 functional safety standard in this domain provides a development framework to manage the risks introduced by this new technology on the market.
There are many similar examples. In the rapidly growing sector of aerial drones, used for various applications such as aerial photography, civil protection, or audiovisual needs, drones are becoming more prominent in helping to contain forest fires by evaluating their direction or detecting the origins of fires. Climate change is causing more unpredictable fires. Drones allow for the monitoring of large areas over extended periods. The obvious risk of falling onto the population must be controlled. To address this, the European Union Aviation Safety Agency (EASA) regulates drone use through the “Easy Access Rules for Unmanned Aircraft Systems” (Regulations (EU) 2019/947 and 2019/945). These regulations specify that confinement within the authorized flight zone of the unmanned aircraft system is critical, and the Light-UAS.2511 requirement, derived from the special condition “Light Unmanned Aircraft Systems – Medium Risk (SC Light-UAS Medium Risk 01 – 17/12/2020),” must be respected. However, there is currently no functional safety framework for this domain.
Methodology
A. Electrification of Vehicles
1) Automobiles
2) Electric Bicycles
3) Agricultural Machines
4) Electric Aircraft
B. Aerial Drone
1) Requirements to Cover
2) Safety Demonstration Methodology
a) Reliability Analysis
b) Safety Analysis
Results
A. The electrification of vehicles
The electrification of vehicles has now become ubiquitous, regardless of the industry. From the earliest to adopt electric technologies, such as automobiles and electric bikes, to the latest electrified vehicles like agricultural machinery and even future aircraft, the goal is to achieve “cleaner” transportation.
Functional Safety methodologies to manage the new risks introduced are now established in the automotive industry, as well as in other vehicle types affected by electrification.
B. The aerial drone
The rise of aerial drones to address climate changes is, for its part, in search of a new framework.
In the absence of such a framework, we have developed a methodology to verify the applicable requirements, particularly the Light-UAS.2511 requirement, through the adaptation of analyses used in the aeronautical world for safety evaluation (SSA), tailored to the domain of aerial drones.
The established methodology was submitted to EASA, which approved it in return. This validates the study that was conducted and formalizes an approach that enables the certification of drones that will have followed it.
Discussion and perspectives
The technological advancements of recent years to address climate changes seem to be accelerating, impacting all sectors.
This rapid shift is reminiscent of the difficulties faced in the automotive world in the 2000s due to the widespread use of electronics, initially without a dedicated Safety Assurance (SdF) standard to guide the developments. However, Safety Assurance standards appear to be well established in most sectors today and are often adapted in their current definitions.
This is not entirely the case for some emerging technologies, such as aerial drones, which require an adaptation of current SdF methodologies. The work we have undertaken provides a response to this lack of standards, as it enables obtaining flight authorization from airworthiness authorities. The future “Means of Compliance” to the requirements governing no-fly zones, likely to be closely modeled after aviation Safety Assurance guides, still need to be established.
Functional Safety is an essential tool to address the changes brought about by the ecological transition and is undoubtedly one of the key responses to today’s and tomorrow’s challenges. It helps manage the new risks associated with major developments in recent years, such as the electrification of vehicles and the use of drones.
This involves, in particular, the integration of new specific safety protections, developed within the framework of Safety Assurance standards or guides, which, depending on the field, are either already existing and applicable as is, or still to be established.
References
- CEN/TC333, EN 15194:2017 – Cycles – Electrically power assisted cycles – EPAC Bicycles
- EASA, Acceptable Means of Compliance and Guidance Material to Regulation (EU) 2019/947 — Issue 1, Amendment 2
- EASA, MOC Light-UAS.2511-01 Issue 1 – Means of Compliance with Light-UAS.2511 “Enhanced Containment”
- EASA, SC Light-UAS Medium Risk 01 Issue 1 – Special Condition for Light Unmanned Aircraft Systems – Medium Risk
- ISO/TC22, ISO 26262:2018 – Road vehicles – Functional safety
- ISO/TC23, ISO 25119:2018 – Tractors and machinery for agriculture and forestry – Safety-related parts of control systems
- ISO/TC199, ISO 13849:2023 – Sécurité des machines – Parties des systèmes de commande relatives à la sécurité
- JARUS WG3, JARUS-DEL-WG3- CS-UAS-D.04 Ed. 1 – JARUS CS-UAS – Recommendations for Certification Specification for Unmanned Aircraft Systems
- JARUS WG6, JAR-DEL-WG6-D.04 Ed. 2 – JARUS guidelines on Specific Operations Risk Assessment (SORA)
- RTCA SC-167 / EUROCAE WG-12, DO-178B – Software considerations in airborne systems and equipment certification
- RTCA SC-180 / EUROCAE WG-46, DO-254 – Design assurance guidance for airborne electronic hardware
- SAE Committee S-18, ARP 4761 – Guidelines and methods for conducting the safety assessment process on civil airborne systems and equipment
- SAE Committee S-18 / EUROCAE WG-63, ARP 4754A – Guidelines for development of civil aircraft and systems
