Semi-active vibration control for wing aileron using stepped magneto-rheological damper

Semi-active control, a relatively new topic in the flutter suppression of wing-aileron systems, depends greatly on the successful combined design of controllers and actuators, such as the magneto-rheological (MR) dampers. This study starts with a novel design of a rotary stepped MR damper of shear mode, which can provide 7 levels of torque by altering the magnetic field area inside. Then, it specifies the problem of flutter control for a 3DOF wing model with such a stepped MR damper installed in the position of aileron rotation axis. Numerical simulation of the flutter suppression based on several control strategies is given to illustrate the effectiveness of the present theory. Comparison with the constant damper torque, the On-Off control and the clipped-optimal control reveals that the sub-optimal control using stepped MR damper works best and increases the critical flutter speed by 16.6%.