Active camber system for lateral stability improvement of urban vehicles

Abstract

A suspension system with the capability of cambering has an additional degree of freedom for changing camber angle to increase the maximum lateral tire force. This study investigates the effects of cambering on overall vehicle stability with emphasis on applications to urban vehicles. A full vehicle model with a reliable tire model including camber effects is employed to investigate the vehicle dynamics behavior under cambering. Besides, a linearized vehicle model is used to analytically study the effects of camber lateral forces on vehicle dynamics. Vehicle behavior for different configurations of camber angles in front and rear wheels is studied and compared. Then, an active camber system is suggested for improvement of vehicle lateral stability. Specifically, performances of active front camber, active rear camber, and their combination are investigated. The results show that a proper strategy for camber control can improve both yaw rate and sideslip angle, simultaneously. Finally, the active front camber system is compared with the well-known active front steering. It is shown that, utilizing more friction forces at the limits, active front camber is more effective in improving maneuverability and lateral stability than active front steering.

An Original Aerodynamic Ducting System to Improve Energy Efficiency in the Automotive Industry

“…Because of this, several studies analyze aerodynamic variables such as drag coefficient [28], vortices [29], turbulence [30], boundary layer, or stability [31], through experimental testing. The preceding literature also proved that prototypes such as the one presented here are also interesting in the evaluation of fatigue life [32,33], and lateral stability improvement [34].…”

Contributions of vehicle dynamics to the energy efficient operation of road and rail vehicles

“…Camber control has also been investigated to improve handling characteristics, stability, steering feel, safety and manoeuvrability (for example [11][12][13][14][15][16]) which gives a good foundation to combine the different research subjects to find control strategies with combined objectives including energy efficiency.…”

Coordinated Chassis Control of 4WD Vehicles Utilizing Differential Braking, Traction Distribution and Active Front Steering

“…Then, satisfying the overall longitudinal driving force, the desired 4WD distribution and the actual control input of the 4WD system can be determined based on the dynamic modeling of the center coupler and ELSD, as in equation 6- (8).…”

“…Yim [6], [7] proposed two unified chassis control systems of ESC and AFS for the under-steer prevention induced by the use of AFS in lateral motion and improved vehicle stability performance, respectively. The intuitive advantage of the integration of active steering and differential braking lies in that, in moderate driving scenario, AFS can handle the mild external disturbances and modify the driver's steering input to optimize the vehicle's lateral performance [8]- [10], and in high speed turning scenario, ESC will step in to decelerate the vehicle and, combined with AFS, produce the desired yaw moment.…”