Autosar stands for Automotive Open System Architecture.
Importance of system design in complex automobile systems.
Importance of Autosar
Modern cars have around 100 Electronic Control Units (ECUs) (e.g., airbag, body control unit).
ECUs consist of sensors, actuators, and microcontrollers.
Microcontrollers manage storage, computation, and communication for ECUs.
The Need for Standardization
Development of software for ECUs depends heavily on specific microcontroller architecture.
Need for software portability; reusability is challenging with different microcontrollers.
Lack of coordination between suppliers and OEMs led to the development of Autosar in 2003.
Goals:
Increase flexibility for product modifications.
Enhance software reliability, quality, and safety requirements.
AUTOSAR Architecture
Composed of three layers:
Application Layer
Real-Time Environment Layer (RTE)
Basic Software Layer (BSW)
Application Layer
Contains application-specific components for executing various tasks.
Made up of:
Application software components.
Ports of these components.
Port interfaces.
Real-Time Environment Layer (RTE)
Middleware layer facilitating communication between application software and BSW.
Utilizes ports to exchange data and invoke functionalities from BSW.
Basic Software Layer (BSW)
Standardized software providing services to Autosar software components.
Comprises:
Service Layer: Interfaces independent of hardware.
ECU Abstraction Layer: Uniform access to ECU functionalities.
Microcontroller Abstraction Layer (MCAL): Direct communication with hardware.
Complex Device Driver (CDD): Manages complex functions requiring special timing and access to microcontroller.
Example Applications
Turn Indicator Mechanism: Software component requests to turn on the bulb, routed through RTE to BSW.
Door Control Unit: Sends door status via CAN. Request goes from the application to the communication layer of BSW, which then transmits the CAN signal.
Conclusion
Autosar simplifies the development and integration of software in automotive systems.
Provides frameworks for hardware/software separation.