Online message delay prediction for model predictive control over controller area network

Abstract

Today's Cyber-Physical Systems (CPS) are typically distributed over several computing nodes communicated through buses such as Controller Area Network (CAN). Their control performance gets degraded due to variable delays incurred by messages on the shared CAN bus. This paper presents a novel online delay prediction method that predicts the message delay at runtime based on real-time traffic information on CAN. It leverages the proposed method to improve control quality, by compensating the message delay in the Model Predictive Control (MPC) algorithm design. It demonstrates that the delay prediction is accurate, and the MPC design which takes the message delay into consideration performs considerably better. It also implements the proposed method on an 8-bit 16MHz ATmega328P microcontroller and measures the execution time overhead. The results clearly indicate that the method is computationally feasible for online usage.