Adaptive IEEE 802.15.4e LLDN scheduler for wireless network control systems

Abstract

An active area of research in the automotive research community is the stability of Long Commercial Vehicles (LCVs) using active trailer steering and/or braking. These LCVs rely on sensor data located across different regions of the tractor and trailers and compose the LCV. Communication of the sensor data to the Electronic Control Unit (ECU) of the active trailer system is performed through a conventional wired bus. The benefits of wireless communication for an LCV are improved flexibility, maintenance, elimination of physical socket connections and, reduction of weight related to the wires in the vehicle. In LCVs there is a natural demarcation point between the tractor and trailers where wireless communications can replace the wired communication bus. This thesis investigates the latency and throughput of wireless communication using IEEE 802.15.4 and IEEE 802.15.4e Low Latency Deterministic Network (LLDN) protocols for different sensor sampling rates in an LCV scenario and creates a guidelines for the system designers to select the right sensor sampling times. Furthermore, it proposes a new adaptive IEEE 802.15.4e LLDN algorithm that computes the optimal timeslot and superframe duration based on the sensor node data inter-arrival times to achieve the desired LCV controller latency that will exhibit stable behaviour. Simulation results confirm that this adaptive IEEE 802.15.4e LLDN algorithm can configure the IEEE 802.15.4e LLDN that present the best results for delay as well maximum throughput for a desired latency.