A Dynamic Rollover Prediction Index of Heavy-Duty Vehicles With a Real-Time Parameter Estimation Algorithm Using NLMS Method
Xinwei Yang, Chaozhong Wu, Yi He, Xiao‐Yun Lu, Tao Chen
Abstract
Rollover accidents are more likely to occur with Heavy-Duty Vehicles (HDV) due to the high center of gravity and large size. A dynamic rollover index ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> ) can describe the transient nature and responses of vehicle states. This study proposes an improved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> to detect real-time rollover events in tripped and untripped conditions. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> combines the roll-plane dynamics of the sprung and unsprung mass and even fully considers vehicle suspension dynamics under uncertain external road inputs. Moreover, a low-cost unknown input observer (UIO) is designed to estimate vehicle roll angle under the uncertain disturbance of road bank. The updating improved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> is in terms of quasi-constant parameters, estimated states and external perturbation. A parameter estimation algorithm based on the Normalized Least Mean Square (NLMS) is developed to observe unmeasurable and time-varying parameters. Furthermore, by investigating the thresholds of roll angle and lateral acceleration, a dynamic predictive rollover threshold is determined with state constraints. The results demonstrate that the proposed parameters estimator is capable of estimating the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c. g.</i> height, roll moment of inertial, suspension roll stiffness, and suspension roll damping within acceptable errors in different driving scenarios. Moreover, the improved <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> can strictly detect rollover in a complex driving scenario. Finally, the proposed dynamic <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RI</i> threshold reduces invalid rollover warnings, predicates the rollover risk and guarantees sufficient response time for controller delay.