Vehicle Dynamics Modelling: Lateral and Longitudinal

Abstract

The design of vehicle control systems requires sufficiently accurate vehicle dynamics modelling to validate a desired closed-loop performance of the system in offline mode prior to real time testing. The implication of lateral and longitudinal dynamics in the vehicle plant model plays a pivotal role in determining the enhanced performance and response of a controlled vehicle model. Previously, the development of a high-fidelity plant modelling with an accurate estimate of lateral dynamics have not been focused and is merely unavailable. The significant factors of road profile and system dynamics including cornering stiffness, roll stiffness, roll damping coefficients, acceleration pedal and brake dynamics comparable to the real-world vehicle are neglected in research studies. The parameters of roll dynamics can be estimated easily but have a significant impact in vehicle navigation, especially in a heavy loaded vehicle. This chapter illustrates the concept of roll dynamics and the factors which influence roll dynamics and mechanism to identify the roll. Furthermore, this paper also proposes the concept of depleting the influences of roll variation and the virtual compensation mechanism for roll dynamics to reduce the impact of road turbulence on the vehicle during navigation. It also investigates vehicle parameter estimation schemes and demonstrates the simulation results of the estimation. The vehicle lateral parameters such as cornering, roll stiffness, or damping ratio are precisely estimated using the parameter optimization methodology. The hypothesis for longitudinal actuators of acceleration pedal and brake position has been illustrated in this paper. Furthermore, the validation approach of the system dynamics is described, and simulation results are evaluated against the off-the-shelf available vehicle dynamics model. The parameterized vehicle dynamics models with precise estimated parameters can be widely used in various applications including stability or lateral control.