Handling stability analysis and collaborative optimization design for an off-road vehicle with compound suspension

Enhancing the handling and stability of off-road vehicles is critical for ensuring driving safety and performance in harsh terrain. This paper proposes a novel integrated analysis and collaborative optimization methodology tailored to address the handling stability limitations of off-road vehicles. A multi-body dynamics model of the full vehicle, including the front torsion bar spring and the rear leaf spring suspension, has been built and validated through the K&C test. On this basis, the vehicle handling stability has been generally analyzed and evaluated with a low score in steady-state steering characteristics. To improve the comprehensive handling stability, a co-simulation framework integrating modeFRONTIER, Adams/Car, and MATLAB has been established to perform the sensitivity analysis and develop an optimal design of a compound suspension system. A surrogate modeling approach combined with the multi-objective particle swarm optimization (MOPSO) algorithm has been employed to execute the collaborative optimization. The results show that the selected design factors prove to show important influence on the handling stability. The handling stability of the vehicle is significantly improved after optimization with the score of the constant-radius cornering test NW increasing by 19.92% and the overall evaluation score N z increasing by 3.62%. The results validate the feasibility of the proposed methodology, which provides a scalable and efficient reference for enhancing the handling stability of off-road vehicles.