Tire Friction Estimation via Saturation State Switching

The patent applies dynamics by switching between two different estimation methods based on the tire's saturation state. When the tire is below saturation, the initial slope method is used; when saturation is detected, the current utilized longitudinal friction method takes over. This dynamic adaptation ensures accurate friction coefficient estimation across all operating conditions, resolving the contradiction between accuracy below saturation and applicability at saturation.

The patent changes the estimation parameter based on the tire's operating state. Below saturation, it uses the initial slope of the tire characteristic curve as the estimation parameter. When saturation occurs, it switches to using the current utilized longitudinal friction as the parameter. This parameter change allows the system to maintain estimation accuracy across different saturation ranges.

The patent segments the tire operating range into two distinct regions: below saturation (linear region) and at saturation (non-linear region). Each segment has its own dedicated estimation method optimized for that region. This segmentation allows the system to maintain high accuracy in both regions while keeping each individual estimation method relatively simple, resolving the contradiction between system complexity and estimation accuracy.

The patent uses feedback by continuously monitoring the tire's saturation state and using this information to determine which estimation method to apply. The saturation detection mechanism provides feedback that triggers the appropriate estimation approach, ensuring accurate friction coefficient estimation while maintaining system simplicity through conditional logic rather than complex continuous modeling.