Abstract:

A cascade-longitudinal-horizontal coupling control strategy for vehicles was designed to improve the performance of autonomous vehicles under low attachment conditions. A vehicle dynamics model was established, a longitudinal and lateral motion controller and a longitudinal and lateral front controllers were
designed to ensure autonomous vehicles can follow the target path; the rear stability controller was designed to calculate the yaw rate and compensate the yaw torque. The following accuracy and stability of vehicles under different adhesion coefficients was analyzed and verified by combining Carsim with Simulink for co-simulation. The results show that the maximum errors of yaw velocity, side slip angle and trajectory following accuracy are reduced by about 38.6%, 45.83% and 5.58%, respectively, before the uncoupled control; the designed controller can effectively improve the following accuracy and stability of the autonomous driving vehicle under low attachment conditions.

Key words: automobile engineering ,  autonomatic drive , low adhesion condition, longitudinal and lateral coupling control, stability control