Introduction <p>The rapid development of the transportation industry has led to increased demand for commercial vehicles, particularly trucks, which are subject to complex driving conditions. These conditions significantly impact the comfort and safety of drivers, as well as the potential for cargo damage due to frequent and severe road bumps. To address these challenges, there is a growing need to design vehicle suspension systems that provide superior vibration isolation, ensuring improved driving stability and safety. Modern heavy-duty vehicles, especially trucks, typically feature air suspensions with adjustable load-bearing capacity and variable stiffness, offering advantages over traditional mechanical and hydraulic suspensions. However, as requirements for ride comfort and safety continue to increase, conventional air suspensions are no longer sufficient to meet the demands of modern transportation. The quasi-zero stiffness air suspension (QZAS) has emerged as an advanced solution, combining high static stiffness with low dynamic stiffness, making it ideal for vibration isolation. QZAS integrates air suspension with a negative stiffness cylinder to balance the positive stiffness of the air suspension. This structure achieves an overall zero stiffness effect at the vibration equilibrium position, significantly reducing the inherent frequency of the suspension system and enhancing ride comfort. Despite its advantages, QZAS systems must adapt to varying road conditions and load weights, which require dynamic adjustments to the air pressure in the negative stiffness cylinders to maintain optimal performance. This paper explores the optimization of air pressure in QZAS systems to enhance vehicle performance under diverse driving conditions.</p> Materials and methods <p>This study employs a multi-objective genetic algorithm for the optimization of four air pressure values in the QZASsystem. The goal is to obtain a Pareto optimal solution set that balances various performance indices related to vibration isolation and vehicle stability. Due to the complexities involved in the inflation and deflation processes of the negative stiffness cylinders, which may cause delays in actuator response and hysteresis effects, the Monte Carlo method is utilized to analyze the system's behavior under varying initial conditions and parameter uncertainties. This method allows for an evaluation of the stability and uncertainty of the optimization results. To further enhance coordination within the suspension system, cooperative game theory (CGT) is applied to allocate appropriate weights to the performance indices, ensuring optimal collaboration between the air suspension components and the negative stiffness cylinders. This approach is specifically designed to address the challenges posed by fluctuating road conditions and dynamic load changes.</p> Results <p>The optimization results show that adjusting the air pressure can significantly improve the acceleration of all four wheels and the body attitude of the vehicle. These enhancements significantly improve vibration isolation and directly contribute to improving the driving safety and comfort of commercial vehicles. The CGt-based optimization method effectively adapts air pressure to different driving scenarios, ensuring optimal suspension pressure.</p> Conclusion <p>In conclusion, the optimization method based on Cooperative Game Theory effectively improves the vibration isolation performance of the QZAS system by optimizing the air pressure in the negative stiffness cylinders. This approach enhances both the safety and comfort of commercial vehicles, making it a promising solution for vibration control. Future work should focus on real-world validation and exploring its potential for other types of suspension systems.</p>