Classic AUTOSAR is a software architecture for automotive electronic control units (ECUs). It comprises an intermediary layer that separates hardware-independent application software from hardware-oriented basic software; both layers communicate using a Runtime Environment (RTE).
Classic AUTOSAR can shorten development time while also providing software reuse across vehicles and OEMs, but there may be challenges associated with using this standard.
Basic software
Traditional vehicle software development for electronic control units (ECUs) was done solely by vehicle manufacturers, leading to duplicated effort, extended development cycles, and limited commercial flexibility when updating either hardware or automotive software. The Classic AUTOSAR platform seeks to address these problems by providing an abstract layer between microcontroller and application software development.
The Classic AUTOSAR architecture consists of three software layers that run on a microcontroller: the application, Runtime Environment (RTE), and basic software layer. RTE’s primary role is facilitating communication between these layers while providing access to them both; the basic software layer provides services, ECU abstraction, and microcontroller abstraction while RTE manages the exchange of data among them all.
Classic AUTOSAR not only defines an architecture and interfaces, but it also specifies a method for configuring the entire system and enhances interoperability between various toolchains to reduce development costs while improving efficiency. Furthermore, Classic AUTOSAR supports multiple software tools available for developing systems.
The Adaptive AUTOSAR standard provides a more flexible approach to standard application interfaces by taking advantage of Ethernet-based communication protocols. It enables dynamic interaction among software components and can be used to develop multi-sensor systems and infotainment; however, it may not meet functional safety requirements such as ISO 26262.
Application software
AUTOSAR’s classic platform utilizes a three-tier software architecture to reduce development time and costs, consisting of application software, basic software, and the runtime environment (RTE). Each layer contains hardware-independent modules that enable applications to access microcontroller functionality via standard interfaces while communicating between software components using a defined communication network. Furthermore, the application layer provides direct access to vehicle sensors and actuators, signal processing functions as well as networking functions.
The application layer features a standard software development methodology and the use of unified language methodologies that make software development simpler for automotive software development. Furthermore, this standard facilitates the incorporation of functional safety requirements into system designs using techniques like model-based testing and fault injection to exercise systems under test as well as performing unit and integration tests on target hardware to verify whether application software fulfills its intended function.
The AUTOSAR Adaptive Platform was developed to meet the demands of modern automotive trends such as V2X connectivity and autonomous driving. It offers a powerful yet flexible E/E architecture, support for over-the-air updates, and real-time functionality; moreover, it is more adaptable in its implementation to adapt better to the hardware used as well as offering efficient communication among ECUs.
Run-time environment
The Classic AUTOSAR software architecture organizes ECU software into three layers, the Application Layer, Runtime Environment (RTE), and Basic Software Layer. This structure allows developers to create software components independent of hardware used or planned for an automotive project while being easily relocated between ECUs during development. Communication among these various layers takes place via RTE which acts as a virtual function bus.
Before AUTOSAR Classic’s introduction, vehicle manufacturers or suppliers often developed software for each electronic control unit (ECU) individually, leading to duplicated efforts among automotive players and lengthy development cycles. AutoSAR’s reusability and scalability requirements make reiterating programs or expanding projects much more feasible than was once the case.
Adaptive AUTOSAR was developed to support emerging trends in the automotive industry such as V2X connectivity and automated driving. To support such trends, more powerful ECUs with increased processing power must be installed, capable of handling larger amounts of real-time data processing; additionally they must communicate with other vehicle systems over networks.
To meet these needs, Adaptive AUTOSAR offers several tools that facilitate the design and verification of ECUs. These tools can detect errors quickly and facilitate debugging processes; additionally, they include static analysis tools which perform automatic inspections to ensure compliance with ISO 26262 functional safety standards and AUTOSAR coding guidelines.
Virtual functional bus
The Virtual Functional Bus (VFB) is an abstraction that separates applications from physical infrastructure. At runtime, this communication mechanism enables SWCs to communicate regardless of where they’re executed in a system (e.g. within one ECU or across different ECUs) with minimal RTE involvement needed to manage this interaction.
VFB accomplishes this by mapping VFB connections onto local connections or network communication technologies such as CAN or FlexRay, making SWCs compatible with any ECU on any vehicle without needing to be tailored specifically for it. Furthermore, this VFB enables the relocation of SWCs between ECUs during development or manufacturing.
Architecture also facilitates software application development without needing hardware-specific knowledge. This is accomplished through decoupling the hardware environment from the application layer via RTE. Application developers typically assemble C language source files at compilation time into one executable file that can then be distributed across individual ECUs using RTE and the AUTOSAR Basic Software at runtime. The VFB and RTE enable transferring and deploying functions onto ECUs even at very late stages of development, providing car manufacturers with reduced time-to-market, increased flexibility, and cost efficiency for their products. In addition, third-party-developed functions can also be integrated more rapidly.
