Anti-Rollover Control of a Counterbalance Forklift Based on Roll Energy Classification

Abstract

This study proposes an energy stability index suitable for a counterbalance forklift, aiming to solve the problem that the traditional vehicle stability index load transfer rate is difficult to accurately judge the stability state of such a forklift. The analysis of the structure of the counterbalance forklift and contact relationship between the body and rear axle are used as bases to establish a two-stage dynamic model and derive real-time instability energy of a forklift truck in the rollover process under different conditions. Additionally, this research proposes an anti-rollover control strategy of the counterbalance forklift based on roll energy classification. The corresponding calculation formula of the forklift energy stability index is selected according to different stability conditions to perform roll energy classification. An anti-rollover oil cylinder and active rear wheel steering are used as an anti-rollover control actuator, and an anti-rollover control is implemented based on model predictive control. Last, a simulation based on European standard operating conditions and real vehicle test verification is conducted. Results show that the anti-rollover control strategy based on roll energy classification can effectively reduce the risk of forklift rollover and improve the stability and active safety of a counterbalance forklift.