Design And Implementation Of Communication Model Based On OSEK/VDX

In the field of modern automotive industry, control systems of vehicles became more and more complex and electronic, enforcing manufacturers to adopt component-based automotive electronic development platform with standard interface and interoperability. Most of the traditional development of Electronic Control Unit (ECU) application software must be in accordance with ECU of specific structure and communication protocol. This traditional development method became inefficient as the amount of ECU increased greatly and the networks became more and more complex in automotive, also the software production has worse reusability and hard to maintain. Therefore, European automotive industry put forward OSEK/VDX standard system to standardize the software development in the automotive electric application field. OSEK/VDX consists of four parts: Operating System, Communication, Net Management and OSEK Implementation Language. This thesis concentrates on OSEK COM, the communication standard of OSEK/VDX. The basic idea of OSEK COM is to encapsulate communication function and offer users with uniform Application Program Interface. These API services can be used to transfer data between tasks and/or interrupt service routines, and they hide the differences between internal and external communication as well as different communication protocols, bus systems and networks.After analyzing the OSEK COM standard, a communication model in which data transfer is based on messages was brought forward to illustrate the process of message reception and transmission. And then this thesis interprets the key mechanisms of OSEK COM including the structure of system objects, message filtering, notification, process of external communication (exchange data between different ECUs). After that this thesis introduces the method of realizing the communication model which accords with the standards and brought forward the main API and ISR functions.In model testing, this thesis designs CAN identifier structure. According to the amount of CAN bus data frame, corresponding disposal were supplied and the function of lower communication layers was simulated on PC. At last, this thesis summarizes the achievements of current work and put forward the work direction in future.