Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2019
Date : August 27, 2019 - August 30, 2019
In this paper, we propose a new system identification method of space structures. Considering operations of space structures, excitation force is usually unmeasurable and unknown. Instead of measuring excitation force, voltage of a piezoelectric transducer that is installed to the space structure is measured. The piezoelectric voltage can be used as an input signal to the structure because it is proportional to the force generated by the piezoelectric transducer. We consider that the excitation force can be represented as unknown periodic functions that are handled as an internal state of the system. Then, system identification is enforceable without measuring the excitation force. Also, two improvements are achieved in general system identification theory in this paper. First, we consider about uncontrollability of the system. The system that deals with the excitation force as internal state has some uncontrollable parts. Second, we introduce a forgetting factor to the sequential system identification theory, which is effective when characteristics of the space structure can be changed. We present performances of the proposed method in the numerical simulation. The simulation result shows that system identification can be implemented measuring the piezoelectric voltage without measuring the excitation force. In addition, it is showed that the proposed method adapts quickly to the change in structural condition.
