Abstract
Development of real-time control system for multi-degree-of-freedom shaking table is considered in this study, in order to cope with advanced dynamic testing of large-scale engineering systems. In recent years, natural disasters and engineering accidents are frequently reported, high-quality dynamic tests to evaluate and ensure the reliability and security of engineered products, is increasingly important. However, the testing machines and control systems developed by the well-known MTS and Instron Corporation are expensive, and the built-in controller cannot be adjusted with flexibility according to the testing requirements. Therefore, the preliminary objective of this thesis is to investigate the development and application of shaking table real-time control systems, including mechanical design, construction, dynamic modeling and analysis, advanced controller design, sensing, and mechtronics. We also search for the solution to real-time issues associated with control, measurement, computation, monitoring and so on. Shaking tables are widely applied in earthquake and civil engineering laboratories to simulate seismic waves and to test the vibration-isolation performance of structural systems. This thesis builds a shaking table with four-axis inputs, three-degrees-of-freedom outputs. The derivation of forward and inverse kinematics is included, in order to establish the relation between actuator displacements and the shaking table position. In the forward kinematics, we ignore the high-order error terms in order to simplify the on-line computation. Then, advanced state feedback controller is developed to enhance the tracking robustness of the shaking table. The dSPACE hardware is used to develop real-time controllers and monitoring interfaces. The real-time control system developed in this thesis contains the functionality of initialization and adjustable control parameters, in order to promote the flexibility of executing dynamic tests. The experimental results prove that regardless of the shaking table with or without carrying structural specimen, the outer-loop state feedback controller is more effective than the built-in controller to keep the tracking accuracy. In the future, the real-time techniques developed in this thesis will be applied to control and testing of a small-scale hydraulic shaking table in National Center for Research on Earthquake Engineering, in order to enhance the testing quality of civil engineering research.