RTOS for Automotive

A Real-Time Operating System (RTOS) is an operating system (OS) that manages hardware resources and activities—including scheduling application programs, writing files to disk, sending data across networks, etc.—concurrently and within predictable time limits. 

What Is an RTOS for Automotive?

For automotive development, an RTOS is software that enables critical features in a car to run with minimal latency. Whereas the OS on a home computer or smartphone can generally provide a good experience even with pauses between inputs and the device reacting, this would be frustrating or dangerous for many auto functions.

As an increasing number of a vehicle’s features become software controlled, ushering in an era of Software-Defined Vehicles, a dependable RTOS for automotive has become essential. The introduction of sophisticated Advanced Driver-Assistance Systems (ADAS) has meant that a fast reaction to environmental factors is now critical to safety. An adaptive cruise control system must act as close to immediately as possible if it detects, for example, a slowing or stationary vehicle ahead in the same lane.

More autonomous features are being added to vehicles, too, which operate through the automotive RTOS. Just as a driver must be attentive and immediately aware of surrounding conditions, the vehicle must process the input from its sensors in real-time and react accordingly when it is self-driving.

Types of Automotive RTOSes

All modern operating systems are designed to run multiple application processes simultaneously via multitasking. The OS scheduler is the key technology ensuring tasks are executed in a timely fashion. This determines when a process from an application will execute, and with an RTOS, the processing time requirements are calculated as tenths of seconds or less. This must be predictable, reliable behavior.

There are four main types of automotive RTOSes, depending on how critical the process execution timing will be.

1. Hard RTOS

This is an RTOS where the scheduler must execute processes within a fixed short time. For example, braking systems or airbags.

2. Soft RTOS

With a soft RTOS, the response time is prioritized but not critical. Timings can be missed occasionally. Possible applications could be media streaming or even satnav maps if autonomous driving systems aren’t using the latter.

3. Real RTOS

This is a Hard RTOS but with even shorter response times. This is more likely found in non-automotive applications such as military missile systems but could be required in advanced self-driving vehicles.

4. Firm RTOS

This is like a Soft RTOS but it is not critical if timings are missed when executing processes. Real-time execution is desirable but not essential.

Popular RTOSes for Automotive

There are many RTOSes in use for a wide range of embedded applications, but automotive has a narrower focus with some key players for specific functions within the ecosystem.

Microsoft’s Windows Embedded Automotive is widely used for infotainment systems in vehicles from leading vehicle brands.

The Automotive Open System Architecture (AUTOSAR) is a software development standard for Automotive RTOS and electronic control units (ECUs). Vendors employing AUTOSAR include KPIT Technologies, RTA-OSEK from ETAS (part of Bosch), and Elektrobit.

Automotive Grade Linux is a version of the popular Linux Open-Source operating system specifically tailored for automotive applications, with RTOS capabilities. Ten automotive brands and 140 subsystem suppliers are members of the project.

The Connected Vehicle System Systems Alliance (COVESA), previously the GENIVI Alliance, is an organization developing reference approaches for automotive systems, including RTOS. Interoperation with AUTOSAR-based systems is available.

BlackBerry® QNX® Automotive was explicitly designed for use in embedded automotive systems, focusing on speed, reliability, and security. BlackBerry QNX is in use in more than 235 million vehicles worldwide. It can control a comprehensive range of automotive ECUs, from telematics to digital cockpit displays to ADAS and active safety to infotainment and instrument clusters.

How to Choose an Automotive RTOS

Choosing the right RTOS for an automotive application depends on the functions it will be performing. A Soft or Firm RTOS will be sufficient for less mission-critical systems such as infotainment. However, a Hard RTOS will be required for safety-focused features such as ADAS. The most reliable Hard or Real RTOS will be essential as greater autonomy and self-driving are built into vehicles.

There are now hundreds of ECUs in a modern vehicle, ranging from interpreting GPS signals to rain-sensing, assessing wheel speed, managing cruise control, and automatic emergency braking. Infotainment systems are becoming more elaborate and now include movie and music streaming services alongside radio, navigation, and dashboard information. Orchestrating all these subsystems into a seamless driver experience requires a suite of RTOSes that can work together without conflict. It has never been more important to select an automotive RTOS as wisely as possible to provide drivers with the best features and functionality.

BlackBerry QNX software is used in more than 235 million vehicles on the road. Automakers and Tier 1s around the world trust BlackBerry QNX to help them build safe, secure and reliable automotive systems.

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