Estimation of Tire Normal Forces including Suspension Dynamics

Rajit Johri,Louis Filipozzi,Ming Kuang,Jose Velazquez Alcantar,Francis Assadian

doi:10.3390/en14092378

Rajit Johri, Louis Filipozzi + Show 3 more

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https://doi.org/10.3390/en14092378

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Abstract

Tire normal forces are difficult to measure, but information on the vehicle normal force can be used in many automotive engineering applications, e.g., rollover detection and vehicle and wheel stability. Previous papers use algebraic equations to estimate the tire normal force. In this article, the estimation of tire normal force is formulated as an input estimation problem. Two observers are proposed to solve this problem by using a quarter-car suspension model. First, the Youla Controller Output Observer framework is presented. It converts the estimation problem into a control problem and produces a Youla parameterized controller as observer. Second, a Kalman filter approach is taken and the input estimation problem is addressed with an Unbiased Minimum Variance Filter. Both methods use accelerometer and suspension deflection sensors to determine the vehicle normal force. The design of the observers is validated in simulation and a sensitivity analysis is performed to evaluate their robustness.

Highlights

The automotive industry has made significant improvements in vehicle safety and driving performance in the last decades thanks to active control systems
The full-car model shown in Figure 1 is assumed to represent the actual vehicle dynamics and the measured ground-truth signals are extracted from the 14 degrees of freedom vehicle model
The estimation of the wheel loads is formulated as an input estimation problem

Summary

Introduction

The automotive industry has made significant improvements in vehicle safety and driving performance in the last decades thanks to active control systems These control systems rely on the measurement and estimation of several parameters and signals such as the wheel slip, sideslip angle. Cho [2] showed that the estimate of tire forces, including tire loads, can be used to implement Global Chassis Control (GCC) systems and to further improve vehicle stability. Another practical application of tire normal force estimation is roll-over avoidance and understeering or oversteering prevention [3]

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