더블베인 로터리 유압엑츄에이터 시스템의 임피던스 제어를 위한 토크서보디자인

Abstract

Hydraulic actuator systems are known to be highly nonlinear and non-differentiable due to many factors, such as leakage, friction and especially, the fluid flow expression through the servo valve. In addition, their parameter fluctuations are greater than those of electrically driven systems. For these reasons, it is relatively difficult to realize not only a stable contact work but also an accurate force control. In order to achieve a high performance force control, an accurate torque servo mechanism is essential. However, a precise torque servo mechanism for a double vane rotary actuator system is not developed yet. Therefore, to obtain an accurate torque servo mechanism, a precise torque model of the exact system model should be found. In this thesis, non-linear equations are set up based on the dynamics of a double vane rotary hydraulic actuator system. Then, to derive a torque model from the equations, the non-linear equations are linearized using the taylor series expansion. Based on the torque model, a structure of a torque servo is proposed. At last, applying this algorithm to a 2-DOF impedance controller, the performance of the design of torque servo is verified.