Recovering tractor stability from an intensive rollover with a momentum flywheel and active steering: System formulation and scale-model verification

Abstract As a representative type of off-road vehicle, agricultural wheeled tractors are driven under varied and complicated road conditions such as plowed and hilly fields. Active control is the essential technique to solve tractor rollover accidents which have been identified as the most fatal incident along with agricultural mechanization. The aim of this study is to provide active correction of tractor attitude in emergency cases by combing a single-axis momentum flywheel system and active steering system. In this study, the time-varying structural nonlinear vehicle dynamic system and its subsystems are formulated during transitions among tractor states under road stimulation. By exploring the phased mutation mechanism of tractor stability, the corresponding stability criteria are proposed. The coordinated tractor safety control strategy was verified using parametric studies in a simulation and scale-model experiments. The results indicated the effective and robust control of tractor safety regarding the independent and integrated active control systems. The proposed approach is expected to provide a theoretical basis and technical support for advanced driver assistance systems applied to future intelligent agricultural vehicles.