Model-based Estimation of Vehicle Roll State for Detection of Impending Vehicle Rollover

Abstract

This paper describes a new methodology for designing model-based estimators for detection of impending vehicle rollover. Vehicle roll motions are induced by maneuvering and road disturbances. An estimator is designed based on a three-degrees-of freedom vehicle maneuvering model and a four-degrees-of freedom half-car suspension model to obtain good estimates of the vehicle roll angle and roll rate in driving situations in which both maneuvering and road disturbances affect the vehicle roll motions. The estimator uses already existing sensors, such as steering wheel angle sensor, lateral acceleration sensor, and yaw rate sensor, on a vehicle equipped with an electronic stability control (ESC) system. Since road disturbance is unknown or very expensive to measure, disturbance-decoupled-observer design technique is used in the design of the estimator. The performance of the estimator is evaluated through computer simulations using a validated vehicle simulator. It is shown that, only with already available sensor measurements, good estimates of the roll angle and roll rate can be obtained using the proposed estimator in driving situations in which both maneuvering and road disturbances affect the vehicle roll motions. A rollover index that indicates rollover danger has been computed using the measured lateral acceleration and yaw rate, and estimated roll angle and roll rate. The rollover index computed using the estimated states is shown to be a good measure for the danger of vehicle rollover.Index Terms-Model-based estimator, Kalman filter, Vehicle Rollover, Rollover index (RI)

Real-time estimation of roll angle and CG height for active rollover prevention applications

“…Hence there is significant research being conducted on development of active rollover prevention systems [1,2,3,4,5,6,7,9,11,13,14]. An active rollover prevention system typically utilizes differential braking to reduce the yaw rate of the vehicle and to slow down the vehicle speed.…”

“…The second equation is a replica of the roll dynamics model. Defme the estimation error t/J =t/J -t/J£f(16) Subtracting equation (15) from equation(13) Vxx +rnh/ Jt = mayh R (cost/J -cost/J£f) + mg hs(sint/J -sint/J£f ) )~-cos 2 ifJ£!~£! ]2 …”

Development of a Refined Rollover Model That Recognizes the Effects of Suspension and Tire Deformation

“…Yi et al described a new methodology to design model-based estimators to detect possible rollovers. Moreover, the proposed estimator can give useful estimates on the roll angle and roll rate, two critical measurements for the risk of vehicle rollover [4]. Seongjin Yim designed a preview controller with the help of a GPS or an inertial measurement unit which can predict a driver's steering input [5].…”

Road bank angle considerations for detection of impending vehicle rollover

“…Yi and Yoon proposed a rollover index (RI) through combining of the lateral ⋆ This work was supported by the "Conseil Régional de Picardie" within the framework of the project "SEDVAC". dynamics model-based estimator and vertical dynamics model-based estimator [Yi (2007)]. Traditionally, some estimation of the vehicle Load Transfer Ratio (LTR) has been used as a basis for the design of rollover prevention systems [Odenthal (1999)].…”