Assessing different control cases of tractor-trailer air suspension in improving DP-HA of driver

Enhancing the control performance of the tractor-trailer air suspensions can improve the driving efficiency and handling ability (DP-HA) of the driver. Based on the dynamic model of a multi-axle tractor-trailer using air suspensions, three different control cases including the control of the damping values in dampers, the control of the stiffness values in airbags, and the control of both the damping and stiffness values of the air suspensions are studied and simulated under different working conditions of the tractor-trailer, respectively. A new control method combining fuzzy controller and genetic algorithm program is also examined and applied to control the damping and stiffness values of the air suspensions. The study indicates that the air suspensions using the different control approaches improve the DP-HA of the driver better than without the control. Besides, the control performance of the damping values is better than that of the stiffness values under all various operation conditions of the tractor-trailer. Significantly, by combining both control methods of the damping values and stiffness values, the isolation performance of the tractor-trailer air suspensions is strongly enhanced in comparison with using the controlled damping or controlled stiffness values. Therefore, the combined control method of both damping values and stiffness values should be developed to further improve the DP-HA of the driver.