Functional Safety of Electric or Hybrid Off-Highway Vehicles - An Embedded Software Viewpoint

To provide growing needs of food, clothing and infrastructure for growing population of the world, off-highway vehicles such as those in construction, agriculture and commercial landscaping are moving towards electrification for enhanced precision, productivity, efficiency and sustainability. It has also paved way to adopt autonomy of these vehicles to address challenges like skilled labour shortage for timely and efficient execution. Despite the tremendous advantages of electrification, be it through completely replacing engine in vehicles or efficiency improvements using hybrid architecture for powertrain and auxiliary power demands, safety remains a significant challenge and critical requirement for off-highway electric vehicles. This paper explains the concept and importance of functional safety in electric off-highway vehicles, and shows how the different standards like ISO 26262, ISO 25119, ISO 13849 being utilized to achieve state of the art in functional safety for different off-highway applications. It focusses on functional safety processes, tools and analysis of electrification components like inverters responsible for control of off-highway vehicle transmission and other functions from an embedded software point of view. It also discusses how the functional safety goals drive the embedded software and hardware requirements, and eventually verification and validation. It will provide an overview of software architecture concepts, control and safety mechanisms and their purpose to avoid or detect failures or faults in the vehicle and take appropriate actions.