Automotive and Functional Safety: FPGAs Offer Programmable Protection

What you’ll learn:

The importance of functional safety in automotive systems.
Requirements for vehicle functional safety.
The role and applications of FPGAs in automotive safety systems.

The automotive industry is undergoing a sweeping transformation as vehicles turn into complex, technology-driven systems. Modern cars have become computers on wheels, integrating an array of sensors, cameras, and advanced operating systems.

This technological leap has brought unprecedented convenience, efficiency, and performance. However, the increased complexity of these vehicles has introduced a new challenge: Ensuring the reliability of the intricate systems, which in turn helps ensure the safety of anyone on the road.

At the heart of this automotive evolution lies the critical concept of functional safety—a top consideration in modern vehicle design and manufacturing. Functional safety covers the measures and processes applied to ensure that automotive systems operate correctly and safely, even in the face of potential failures.

As vehicles rely more on electronic systems for critical functions, from steering and braking to advanced driver-assistance features (ADAS), the importance of robust functional-safety measures can’t be overstated. This is vital for overall road safety, as the number of electric vehicles (EVs) on the road is projected to rise to 240 million by 2030, with many EVs incorporating advanced ADAS functionality in an attempt to reduce accidents/loss of life.

Field-programmable gate arrays (FPGAs) are emerging as a key technology in the ongoing quest to make the roads safer through advanced automotive technology. This article delves into the technical aspects of functional safety in automotive systems, with a particular focus on the pivotal role of FPGAs in meeting the rigorous safety requirements of today's vehicles on the road.

Functional Safety in Automotive Systems

Functional safety is defined as the absence of unreasonable risk due to hazards caused by the malfunctioning behavior of electrical/electronic systems. In the context of automotive, this means ensuring that all safety systems operate correctly in response to both inputs and failures, thereby minimizing the risk of physical injury.

ISO 26262, the International Organization of Standardization’s regulation for the functional safety of electrical and electronic systems in automobiles, guides the implementation of functional safety across the industry. It was introduced in 2011 before its latest revision in 2018. ISO 26262 uses the Automotive Safety Integrity Level (ASIL) rating to measure the safety of each feature of a car.

For context, the ASIL rating includes the following measures:

Failures in time (FIT): This metric quantifies the acceptable rate of failures for a vehicle within a given time period.
Safety concept: This concept determines how a failure is detected and how it should be controlled.
Safety requirements: This dictates the appropriate response to any given failure in the vehicle.

The application of functional-safety principles extends beyond individual components to encompass the entire vehicle. This holistic approach ensures that safety functions like braking, steering, and ADAS work together seamlessly to protect occupants and everyone else on the road. As vehicles become increasingly complex and interconnected, functional safety becomes even more critical.

Why FPGAs for Functional Safety?

FPGAs are emerging as a crucial technology in addressing the challenges of implementing functional safety in automotive systems. They offer a unique combination of flexibility and performance, suiting them for safety-critical automotive functions by providing several key advantages. One of the most significant advantages of FPGAs in automotive safety systems is their ability to facilitate rapid updates and installations of new safety features in vehicles already in operation.

Unlike traditional processors, FPGAs can be reprogrammed remotely, enabling manufacturers to push out critical safety updates without requiring physical access to the vehicle. For instance, if a new algorithm is developed to improve the accuracy of collision detection, it can be deployed across an entire fleet of vehicles through over-the-air updates.

Such flexibility allows for automakers to quickly respond to newly discovered safety issues or changing regulatory requirements, enhancing the overall safety of vehicles already on the road. Other key advantages of FPGAs include:

Guaranteed performance: FPGAs promise consistent, low-latency processing times, which are essential for real-time safety applications.
Parallel processing: FPGAs can perform multiple tasks at once, enabling them to handle data from several sensors simultaneously.
Resiliency: FPGAs are durable and capable of withstanding hard environmental conditions—including temperature variations, shock, and vibrations—making them well-suited for the demanding conditions vehicles encounter on the road.

In automotive safety systems, FPGAs’ real-time parallel-processing capabilities facilitate efficient multi-camera and multi-display integration. They can process multiple sensor inputs simultaneously, which is crucial for time-sensitive operations like collision avoidance.

In addition, they can efficiently handle the high-bandwidth requirements of multiple video streams, performing real-time image processing while driving multiple displays. This supports local dimming capabilities within automotive LCD panels to enhance viewability in difficult lighting conditions — further increasing the contrast ratio and improving black levels by selectively dimming or turning off certain areas of the screen's backlighting.

FPGAs provide the fast and responsive processing needed for adjusting backlight zones, controlling LED brightness, and running complex or customized algorithms. Enhanced display quality reduces strain during difficult lighting conditions. FPGAs can also support safety-critical information even if source content freezes or is lost. Finally, they enable flexible, high-speed I/O and can withstand harsh environmental conditions.

FPGAs offer a balance of flexibility, performance, and reliability, which makes them an excellent to handle the demanding requirements of automotive safety systems. Their ability to be updated in the field also ensures that features can be improved over the vehicle's lifetime, a crucial advantage in the rapidly evolving landscape of automotive technology.

FPGA Applications in Automotive Safety Systems

FPGAs have found their way into various critical safety applications within modern vehicles. Some important areas in this context include:

Advanced driver-assistance systems (ADAS): FPGAs process data from multiple sensors in real-time, enabling features like lane-departure warnings, adaptive cruise control, and automatic emergency braking.
Autonomous-driving systems: FPGAs are playing a vital role in the evolution of self-driving cars. Their parallel-processing capabilities and low-latency data processing enable self-driving cars to effectively handle the massive amount of data from sensors.
Smart airbag systems: FPGAs can process inputs from multiple sensors to make rapid decisions about airbag deployment, adjusting the force and timing based on factors like occupant position, seatbelt status, and crash severity.

In each of these applications, FPGAs improve system performance by offering faster processing speeds, lower latency, and greater flexibility compared to traditional systems. This translates to quicker reaction times in safety-critical situations and the ability to implement more sophisticated safety algorithms.

Fostering a Safer Future for the Automotive Industry

As the automotive industry continues to evolve, functional safety will remain a significant concern in vehicle design and manufacturing. FPGAs have emerged as a pivotal technology to address the challenges of implementing robust safety systems in modern vehicles. Their unique combination of flexibility, performance, deterministic latency, and reliability makes them ideal for meeting the precise requirements of automotive safety applications.

FPGAs' ability to be reprogrammed and updated in the field ensures that features can continually improve throughout the vehicle’s lifetime. This adaptability, coupled with their capacity for real-time processing and parallel computing, raises FPGAs to the top of automotive safety innovation. As vehicles become increasingly complex and autonomous, the importance of FGPAs in ensuring the safety and reliability of critical systems will continue to escalate for years to come.