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Subjective steering feel tuning and objective verification tests are conducted on vehicle prototypes that are a subset of the total number of buildable combinations of body style, drivetrain and tires. Limited development time, high prototype vehicle cost, and hence limited number of available prototypes are factors that affect the ability to tune and verify all the possible configurations. A new model-based process and a toolset have been developed to enhance the existing steering development process such that steering tuning efficiency and performance robustness can be improved. The innovative method utilizes the existing vehicle dynamics simulation and/or physical test data in conjunction with steering system control models, and provides users with simple interfaces which can be used by either CAE or development engineers to perform virtual tuning of the vehicle steering feel to meet performance targets.

Evaluation of electric steering (EPAS) system performance using vehicle specific load conditions is important for steering system design validation and vehicle steering performance tuning. Using real-time vehicle dynamics mathematical models is one approach for generating steering loads in steering hardware-in-the-loop (HIL) testing. However achieving a good correlation of simplified mathematical models with real vehicle dynamics is a challenge. Using rack force models from measured steering tie rod forces or from simulations using a high-fidelity vehicle dynamics model is an effective data-driven modelling method for testing EPAS systems under vehicle specific load conditions. Rack force models are identified from physical measurements or validated vehicle simulations of selected steering test maneuvers. The rack force models have been applied in steering system performance evaluation, benchmarking, and steering model validation.