A wireless communication based active safety system for articulated heavy vehicles

Abstract

To date, various active safety systems, have been developed to improve the safety of road vehicles. This dissertation presents a novel active trailer steering (ATS) system using wireless communication to exchange data among controllers and sensors allocated on the leading and trailing units of an articulated heavy vehicle (AHV). Conventionally, integrating the sensors, actuators, and controllers located on the leading and trailing units of the vehicle needs wired connections. The physical connection at the articulation joint increases the risk of disconnections and damages. Adopting a wireless communication system displays pronounced advantages, including flexibility, cost-effectiveness and ease of maintenance. For AHV's lateral stability control using wireless communication based ATS, addressing the problem of data delay and loss is the main challenge of this study. Innovative solutions have been proposed to tackle the challenges and numerical simulations have been conducted to evaluate the applicability and effectiveness of the proposed techniques for wireless communication based ATS. To this end, a realistic co-simulation platform is designed: the wireless communication based ATS system is constructed in MATLAB/Simulink; the virtual AHV is built in TruckSim; by means of integrating the ATS system and the virtual AHV, the co-simulation can be performed. As a preliminary design, a gain scheduler is introduced to compensate for the effect of data delay and stabilize the AHV. Later, in order to ensure the performance of the ATS control, a Kalman filter-based estimator is introduced. The estimator uses the available dynamic data to estimate the current states of the AHV in case some sensor data is not available. Several design parameters of the communication system based on dedicated short range communication (DSRC) standard such as modulation, quantization, channel estimation algorithm and transmit diversity have been studied. The effect of each parameter on AHV lateral stability is reviewed to propose proper configuration of the DSRC standard. Finally, an adaptive extended Kalman filter is introduced to mitigate the effects of asynchronous time delay on the AHV lateral stability. This thesis initiates the concept of wireless communication based ATS systems for AHVs and provides valuable guidance for such design and development.