A study on dynamics of electric load simulator using spring beam and feedforward control technique

In order to design and test rudder systems of high dynamic aircraft (HDA), the electric rudder load simulator (ERLS) with spring beam is designed in this paper. The mathematical models of ERLS with spring beam are established. By using spring beam, the loading system´s stability and response capability are analyzed under various stiffness coefficients. Analytical formulas of disturbance torque are deduced. According to the invariance theory, a feedforward compensation controller adopted rudder angular velocity is designed to suppress disturbance torque. The stiffness coefficient of spring beam is calculated in the real loading test. The amplitude of sinusoidal load torque is less than 9.73Nmiddotm. Experiments show that the amplitude distinction between the load torque and the command torque is 3.9% and the phase distinction is 2.7deg.