Multi-Objective Robust Optimization for a Parallel Link Steering System: A Six Sigma and Monte Carlo Approach

The steering system is one of the most important assemblies for the vehicle. It allows the vehicle to steer according to the driver’s intention. For an ideal steering system, the steering angle for the wheel on the left and right side should obey the Ackman equation. To achieve this goal, the optimization method is usually initiated to determine the coordinates of the hard points for the steering system. However, the location of hard points varies due to the manufacturing error of the components and wear caused by friction during their working life. To decrease the influence of geometry parameter error, and system mass, and improve the robust performance of the steering system, the optimization based on Six Sigma and Monte Carlo approach is used to optimize the steering system for an off-road vehicle. At last, the effect is proved by the comparison of other methods. The maximum error of the steering angle is decreased from 7.78° to 2.14°, while the mass of the steering system is reduced by 3.15%. Thus, the vehicle handling performance and fuel efficiency are improved.