Method and system for determining friction between the ground and a tire of a vehicle

US10632978B2 · kind B2 · utility

Assignee

• VOLVO CAR CORPORATION · SE

Inventors

• Tony Gustafsson · Skintebo, SE
• Mats Jonasson · Partille, SE

Key dates

• Filing date: Oct 6, 2017
• Grant date: Apr 28, 2020
• Expiry date: Sep 13, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60T2250/042
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

There is provided a method for estimating friction between a tire of a vehicle and a road surface, the method comprising acquiring, a front wheel axle torque, a rear wheel axle torque, a vehicle longitudinal acceleration, a vehicle pitch rate and wheel rotational velocities. The method further comprises determining a front wheel normal force and a rear wheel normal force, based on a center of gravity of the vehicle and the longitudinal acceleration; determining a longitudinal tire stiffness, jointly determining a vehicle longitudinal velocity, based on the wheel rotational velocities and vehicle longitudinal acceleration, and a vehicle pitch angle relative to the horizontal plane based on the vehicle pitch rate; and determining a friction coefficient between tires and ground based on the front and rear wheel axle torque, the front wheel normal force and the joint estimation of pitch angle and vehicle longitudinal velocity. There is also provided a system for performing the described method.