Implementation of controller area network for automotive applications

Abstract

The Controller Area Network (CAN) is a serial,asynchronous, multi-master communication protocol invented mainly for connecting electronic control modules in automotive applications needing high levels of data integrity and data rates of up to 1 Mbit/s. In reality the field of application of CAN is not only limited to automotive applications nowadays. It is now using in fields like industrial automation, medical equipments, and home automation. The objective of this work is to implement a CAN network for some real time control system. Here the system consisting of three application nodes; Anti-Lock braking system, Adaptive Cruise Control, and seat belt module, which are crucial parts in today‟s vehicles.The hardware part of this work consists of a simple dc motor controlled electric vehicle, three MC9S12DP256B microcontroller modules as three nodes, and a stepper motor arrangement for controlling the speed. The CAN Network is implemented using the CAN modules available in the microcontroller as on chip peripheral. An external transceiver MC33388 is using for each node to drive the network. The ABS and ACC algorithms are implemented using the fuzzy logic support of the microcontroller. The operation of the system is as follows: If any sudden brake applied to the brake pedal the ABS module will be activated. By monitoring the slip ratio and brake pressure applied ABS controls the vehicle speed. In the meantime it will send a message to the seat belt module to activate the system. If the ACC module switched on, it will continuously monitors any forward obstacle is there in the front line of the vehicle, and if it detects any the module will inform the ABS module to take the necessary action.In this thesis work main concern is to implement the CAN network to a more complex real time systems. The CAN network can apply to even more complex control systems by increasing its nodes. Depending on the application different CAN nodes have different CAN messaging needs. By using improved versions of CAN like, flexRay CAN, Time Triggered CAN (TTCAN), and by decentralizing the network again with sub network protocols like LIN we can achieve different application needs.