VEHICLE PLATOON CONTROL USING NEGATIVE IMAGINARY SYSTEMS THEORY

Abstract

The platooning of connected and automated vehicles is expected to have a transformative impact on road transportation in upcoming times. Platooning can improve traffic flow and reduce congestion, as the vehicles operate at optimal speeds and maintain consistent distances, increasing road capacity. Safety is also a major benefit, as automated systems in a platoon can react more quickly and accurately than human drivers, reducing the likelihood of accidents caused by human error. From saving fuel to improving safety standards the benefits of vehicle platooning are multifold. In this work, we are using the results of a new emerging theory of Negative Imaginary systems to stabilize and ensure proper tracking of the vehicle platoon. Although Negative Imaginary systems have been extensively studied due to their wide variety of usage from vibration control of mechanical structures to nano-positioning systems, the use of NI theory for the control of vehicle platoons remains relatively unexplored. The initial part of this work involves modeling vehicle dynamics using Newton’s Laws, which results in a nonlinear model. Each vehicle in the platoon is represented as a dynamic system through state-space representations. The limitations of the non linear vehicle model have been explored and a linear state space model is developed using feedback linearization technique. The conditions under which the vehicle model retains its negative imaginary characteristics are specified. The communication links within the vehicle platoon can be modelled using a graph which provides a simple and elegant formation. This information is encapsulated in the Laplacian matrix which has been used in the model accordingly. The linearized vehicle model developed is used a positive feedback loop with the SNI controller and the Negative Imaginary theory results are used to verify stability in a mathematical framework. Different graph topologies and reference inputs are used to perform the modeling and simulation of the vehicle platoon model in MATLAB to provide an idea of the practical feasibility and usage of these concepts. Disturbances have also been added to showcase the robustness of the platoon setup. The final results demonstrate that the practical outcomes are consistent with our theoretical expectations.