OSEK Based Embedded Networked Controller Handling Communication Delays

Abstract

The paper presents a new embedded networked controller designed for vehicle driveline oscillations damping. To benefit of increased safety and predictability, the controller's algorithm is developed under OSEK/VDX realtime operating system. The implementation is tailored to fit available embedded architecture's resources. Main challenge refers to the configuration of accepted delays, taking into account the required memory consumption and execution times. The controller supports asynchronous exchanges of data, being able to handle certain communication delays. The discrete-time model of the closed-loop controller area network (CAN) based system is obtained by means of polytopic approximation techniques. The suggested embedded controller is designed according to one step ahead predictive control algorithm with flexible control Lyapunov function, assuming that the model admits polytopic uncertainty and hard constraints. If the Lyapunov function is appropriately chosen, the command computation involves solving a single linear program at each sampling period. The proposed approach is experimentally verified using an industrial test-bench setup consisting of a Freescale based electronic control unit (which implements the controller) linked via a CAN bus with a dSPACE MicroAutoBox plant simulator.

Hybrid message conversion technique to reduce jitter in CAN based distributed embedded system

“…Total 111 bits are used for 8-byte data transmission without bit stuffing and if one consider worst case scenario then 135 bits are required to represent message with 8-byte data field [9]. This Message length variation cause by bit stuffing mechanism effects on predictability of CAN network transmission scheduling of real time system results in inefficient operation of data transmission [14].…”