SUV Multi-Link Rigid Axle Control Links Optimization for Ride and Handling Improvement

In automotive world role of suspension system is to absorb vibrations from the road, and to provide stability while vehicle is going over bumps or uneven roads, cornering, acceleration and braking etc. For body on frame SUVs which are typically characterized by high center of gravity, it is quite critical to find best balance in ensuring stability of the vehicle and having comfortable ride performance. Rigid axle rear suspension is quite a typical choice in such vehicles, wherein lower and upper control links are two important components subjected to lateral, longitudinal, and vertical loads. These links allow the vehicle to move smoothly throughout the entire range of suspension travel. Kinematics and compliance optimization of these links is a major factor in definition of ride-handling performance of the vehicle. The present study describes key challenges and methodology to define position as well as orientation of control links, where-in multiple inter-related handling and comfort metrics defined to perform sensitivity study. Multi-body dynamics model developed with correlation of physical kinematics and compliance as well as full vehicle ride-handling data is utilized to perform sensitivity analysis. Key contributors such as roll steer and wheel recession have inverse relationship depending on side swing arm length and angle, leading to requirement of investigation techniques to optimize these parameters. The result shows that proposed investigation methodology provides the best suitable ride-handling full vehicle performance metrics.