Dimensionless Sensitivity Methods to Identify Vehicle Cornering Stiffness From Yaw Rate Measurements

A simplified method of identifying a dynamic model is presented that utilizes explicit and implicit coupling between Bode parameter sensitivities. This focus of this work is the identification, in real-time, of the Cornering Stiffness parameter. This parameter governs the tire-road interaction within the simplified bicycle model description of vehicle chassis dynamics at highway speeds. This novel sensitivity coupling method, discovered earlier as sensitivity invariance in circuit network analysis, explicitly limits the possible parameter gradients of the system model to a very small subspace. By constraining the parameter identification or adaptation to solely this possible subspace, a simplified and efficient parameter identification can be obtained at a reduced computational and modelling cost. Both simulation and experimental implementation on a research vehicle under changing road conditions are presented.