Development and Performance Evaluation of Indigenous Control System of 500 Kg Payload Six-DOF Shake Table

Abstract

Shake Tables are used to simulate the effects of earthquake loading on specimen structures and conduct experimental research in the areas of vibration, structural testing and safety assessment. In India, most high-capacity Shake Table installations are imported. Refuelling Technology Division, Reactor Design and Development Group, BARC has indigenously developed a 500 kg payload six-DOF Shake Table and commissioned at BARC. Synchronous control of all the eight actuators of the Table is required to control the Shake Table. Each actuator is provided with position, acceleration, differential pressure and load feedback sensors. A total of 40 feedback sensors are used in the Shake Table control algorithm with a control loop update rate of 1 kHz. It is required to acquire various parameters during Table control in order to do offline analysis and also to use in control strategies like experimental system identification and iterative tuning. The design and development of electronic control system for six-DOF Shake Table also includes implementation of various control methods such as Degrees of freedom (DOF) control, force balance control, and three-variable control (TVC) on a suitable electronic system. No generic hardware and software that satisfies all the control requirement of the Shake Table is readily available. Design and Development of an electronic control system that satisfies all the control requirements of the Shake Table is described in this paper. This development is based on four numbers of indigenously developed Double Actuator Controller with Dual CAN bus Interface (DACCI) networked through CAN bus. This paper describes Control and Instrumentation architecture, specifications and performance of the indigenously developed control system of the Shake Table.