LAUSR

The active safety control of vehicles during braking-in-turn maneuver involves longitudinal and lateral dynamic control. The lateral stability and braking performance of vehicles can be ensured by properly coordinating the longitudinal and lateral forces of tires. In this study, a control system with a three-layer structure is used to achieve the above-mentioned purpose. The expected yaw rate and sideslip angle are adopted to calculate the direct yaw moment to guarantee the lateral stability of vehicles in the motion tracking layer. Considering the minimization of tire workload usage and braking force deviation as optimization objectives, torque allocation control is achieved for the direct yaw moment with lateral stability and the upper bound of longitudinal force (UBLF) of tires as constraint in the torque allocation layer. In the braking hydraulic pressure control layer, the hydraulic pressure in the wheel cylinder is adjusted according to the expected braking force of the wheel. This study proposes a method for determining the UBLF based on the optimal slip ratio (UBLF_OSR), which cannot only avoid obtaining the lateral force of tires but also directly restrict the distribution of tire force. The control system performance is analyzed on the basis of MATLAB/AMESim co-simulation. Results show that the proposed collaborative control strategy of lateral stability and braking performance ensures the lateral stability and braking performance during braking-in-turn maneuver.