| Control of high-precision machinery is necessary to understand manufacturing defects, maintain quality control, and obtain desired dimensional accuracy, surface roughness, and tolerances. When a controller is designed for high-precision applications, the effect of structural and parametric uncertainty, disturbances, and noise play a significantly more important role in the system performance. The level of modeling required to accurately represent the systems' structure, parameters, noise, disturbances, non-linearity, and etc. to design a high-precision controller will require expert knowledge and significant time investments. In practice, a significant amount of time is spent on tuning the controller even after the modeling and initial controller design has been accomplished.; An alternative to the above control design approach is to build a model via system identification and design a controller from the identified system. System identification can be used to build a model that minimizes the difference between the actual system response and the model response when acted on by the same input while incorporating the actual plant's disturbance and noise into the model. System identification has the potential to save valuable time and resources in industrial applications because it uses input-output data from the system to build a model thereby eliminating the difficulty of modeling by physical laws.; System identification was used to build an accurate model of a high-precision measurement system. The model built by system identification was compared to modeling by first laws and showed extremely similar results. Pole-placement control design based on the identified system was used to place the systems' dominant poles. The necessary gains to achieve the desired system response were determined by using the identified model and knowledge of the controller structure. The performance of the model-based controller was compared to actual data of the system and showed that control based on the identified model can be used to accurately control the precision measuring machine. |
