Practical and Efficient System Identification of Precision Gantry Systems
This research develops a procedure to eciently measure the multi input multi output frequency response of precision gantry systems. A precision gantry considered here is dened as two axes moving a bridge in tandem with a third axis mounted to the bridge. An e cient method of measuring the frequency response will decrease the total time required for designing a controller, and higher volumes of gantries can be processed in a set amount of time. Sequential, random phase multisine signals are chosen as an excitation signal for the system identication. A model guided methodology based on system parameters determines how many locations at which the frequency response should be measured, as the response varies with axis location. Guidelines are developed and used to determine that the frequency response of the gantry base and workpoint can be measured using accelerometers in order to provide information about system behavior. The frequency response data is processed using multi input multi output techniques to provide a meaningful, straightforward presentation. The procedure is then structured into an automated program such that minimal user input is necessary. The result is an automated process that can measure and present the multi input multi output frequency response in a deterministic and repeatable manner. The automated procedure is also tested and validated on a sample of industrial gantries.