`Mathematical Problems in EngineeringVolume 2010 (2010), Article ID 541809, 18 pagesdoi:10.1155/2010/541809`
Research Article

## Application of Recursive Least Square Algorithm on Estimation of Vehicle Sideslip Angle and Road Friction

1Department of Automobile Engineering, Beihang University, 37 Xueyuan Road, Haidian District, Beijing 100083, China
2Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA

Received 3 August 2009; Revised 5 December 2009; Accepted 10 February 2010

Copyright © 2010 Nenggen Ding and Saied Taheri. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### Abstract

A recursive least square (RLS) algorithm for estimation of vehicle sideslip angle and road friction coefficient is proposed. The algorithm uses the information from sensors onboard vehicle and control inputs from the control logic and is intended to provide the essential information for active safety systems such as active steering, direct yaw moment control, or their combination. Based on a simple two-degree-of-freedom (DOF) vehicle model, the algorithm minimizes the squared errors between estimated lateral acceleration and yaw acceleration of the vehicle and their measured values. The algorithm also utilizes available control inputs such as active steering angle and wheel brake torques. The proposed algorithm is evaluated using an 8-DOF full vehicle simulation model including all essential nonlinearities and an integrated active front steering and direct yaw moment control on dry and slippery roads.