by Rohit Allen, Clemson Automotive Engineering Graduate Student

About Autosar

AUTOSAR (AUTomotive Open System ARchitecture) was formed in July 2003 by the automotive manufacturers BMW Group, DaimlerChrysler and Volkswagen, and by the automotive system suppliers Bosch, Continental and Siemens VDO(now Continental AG). It provides an open and standardized automotive software architecture for developing vehicular software, user interfaces and management.

AUTOSAR aims to improve complexity management of highly integrated E/E architectures by high reusability and exchangeability of Software modules between OEMs and suppliers. It aims to standardize the software architecture of ECUs and paves the way for innovative electronic systems that improves the performance, safety and environmental friendliness. The hardware and software will be widely independent of each other reducing the development time and costs. The reuse of software by OEMs and the suppliers also helps to increase the quality and efficiency.

AUTOSAR software architecture

To actualize the goal of AUTOSAR pertaining to dividing the application software from base modules and functions, the vehicle electronics is abstracted and subdivided into several layers as shown below.

Next to the hardware is the microcontroller abstraction layer , which maps the microcontroller’s functions and periphery. This layer defines interfaces for memory, I/O drivers and its communication connections. The objective is to have a hardware-independent API but a hardware-dependent implementation.

The second layer is the ECU abstraction layer. The internal hardware of the ECU is defined here and the drivers for the ECU’s external periphery are provided. Thus the purpose of this layer is to abstract the other components on the ECU printed circuit board.

The third layer is the Services Layer. This layer is already largely independent of the hardware (the operating system needs a timer) and its task is to handle the different types of background services needed like memory management, bus communication services , network services, NVRAM handling, operating system etc.

The RTE (RunTime Environment) represents the fourth and the final layer. In this layer the abstraction of the application from the basic software occurs. The RTE handles integration of the application software and controls the exchange of data between application and the basic software. It is only because of this layer that it is possible to reuse application software, since the defined interfaces allow application software to be developed and transferred to any other AUTOSAR-conformant ECUs without special knowledge of the later hardware to be used. All software components running above the RTE are hardware independent components.

Members of AUTOSAR

There are four types of membership for AUTOSAR:

Core (founding) members

• Organizational and Administrative control
• Leadership and involvement in Working Groups

Premium members

• Leadership and involvement in Working Groups
• Accessibility to current information
• Technical contribution

Associate members

• Access to finalized documents
• Utilization of AUTOSAR standard

Development members and Attendees

Benefits of AUTOSAR

From the viewpoint of an OEM, the increased application of standard software modules will release valuable resources to focus on developing innovative functions. By reusing software modules across product lines and customers, suppliers will be able to reduce their development effort and risk, reducing the development cost and time, and minimize the levels of product proliferation. It also helps to improve the quality and efficiency. The use of standardized interfaces instead of proprietary interfaces and the resulting increase in transparency will greatly benefit both tool providers and new market entrants. Also the hardware and software will be independent of each other. The scope of AUTOSAR includes body electronics, powertrain, chassis and safety as well as multimedia systems, telematics and human-machine-interface.

For More Information

[1] AUTOSAR, AutoSAR Website.

[2] AUTOSAR: A first glance, YouTube, Jan 2010.

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