Output Position Control of Two-Mass Systems Based on Fully Actuated System and Singular Perturbation Approaches

Two-mass systems (TMSs) have been widely used to describe the typical dynamics of flexible servo systems. This article studies the output position control of TMSs based on fully actuated system (FAS) and singular perturbation (SP) approaches. In the proposed scheme, the TMS dynamics is first separated into two FAS models based on fast and slow time scales. The slow system model can be employed in tracking controller design and the fast system model is used for vibration suppression control. FAS approach greatly simplifies control system synthesize and analysis, but requires the full system states and suffers from the control issues of uncertain dynamics. To handle these difficulties, a linear extended state observer is designed based on the high-order FAS model for the state estimation, and a disturbance observer is introduced to attenuate the effect of unknown disturbances. The stability of the control system is analyzed under parameter uncertainties based on SP theory with three time scales. Practical experiments are compared to illustrate the efficiency and advantages of the proposed control approach over some existing methods.