Pickups Vehicle Dynamics: Ride and Skate 2003-01-3588
The driver judges his vehicle based on subjective aspects. Vehicle dynamics characteristics including ride and handling have a major impact on this evaluation. For this reason, vehicle manufactures have grown investments in order to improve vehicle dynamics behavior.
Subjective evaluation and customer satisfaction research show which dynamic characteristics need to be improved. CAE models, after being validated based on experimental measures, give a good insight on vehicle dynamic behavior and guide change proposals. At end, new subjective evaluations and measures are carried out in order to check the real improvement of CAE proposals.
This work shows the use of the described methodology for a pickup vehicle dynamics evaluation. One of the major complains of pickup drives is related to ride quality. Thinking of that feature the evaluation process considers several phenomena, such as abruptness, front topping, front bottoming, head toss and rear aftershake. CAE results showed potential ride improvement by changing spring rates, shocks absorber curves, stabilizer bar diameter and jounce rebound stops. Ride improvements were checked by subjective evaluation and experimental measurements.
Handling evaluations were also carried out due to suspension changes. One phenomenon fully investigated was skating. Several suspension characteristics such as rear axle tramp, rollsteer and roll center height were quantified regarding their influence on skate. This study makes it possible to understand the real source of lateral forces for stright line skate and this discovery is the major contribution of this work. Some proposals were defined based on this evaluation. The effectiveness of each proposal was also evaluated subjectively and objectively in a prototype vehicle.
The methodology presented in this work helps to understand the vehicle dynamic behavior and guides suspension changes in order to improve vehicle ride and handling. A methodology like this is essential to accomplish the development in a short time basis and to avoid undesirable changes near production start date.