The Approach to Design Control System for the Electric Drive with Flexible Mechanics

Research in this paper is devoted to optimal control design approach for electric drives used in mechanical systems with significant flexibilities, such as robot manipulators with long and flexible arms or similar setups. All electric drive systems are divided into three typical structures, providing the regulation of torque, speed and position. Transfer functions of the dynamic stiffness of mechanical characteristics are recorded. It is shown that for any structure of the electric drive there is an optimal stiffness of the mechanical characteristic, which provides the maximum damping capacity of elastic vibrations by means of the electric drive. Mechanical oscillations given rise to torsional and bending deformations are considered in the article. Unfortunately, the parameters of the mechanical part of the electric drive, which depend on the optimal stiffness, are often unknown, or they change in operation. In this article recommendations on the construction of electric drive systems using artificial intelligence elements have been developed. In order to achieve maximum damping capabilities and to increase dynamic positioning accuracy, various approaches are introduced. Given recommendations should help engineers to select effective control strategy during design phase, whenever target mechanical system is considered to be flexible and requirements for positioning accuracy are high. Simulations were made in MATLAB / Simulink environment.