Empirical Model Functional Form for Electric Power Steering Systems

摘要

The present invention provides a novel empirical model functional form for electric power steering (EPS) systems for active safety hardware in-the-loop (HIL) and software in-the-loop (SIL) controls development. Only the overlay friction is included in the rack friction element 1. This is a single friction element with tunable parameters for real-time application. Steering friction is handled indirectly by adjusting the EPS overall torque 2 and 3. This eliminates switching between friction models based on input type and the associated discontinuity in friction force. The EPS motor inertia, friction and damping are kinematically reflected into the rack mass and overlay rack friction and damping 4 and 5. This eliminates the high frequency eigenvalue associated with the EPS motor inertia and its torque delivery mechanism's stiffness. The result is an empirical EPS system model suitable for real-time application.