Research On Inertia Identification Of AC Servo System

Alternating Current (AC) servo system has the defect that is very sensitive to the disturbance signal. The change of inertia or torque of the load restricts the improvement of AC servo system's performance. This thesis using Permanent Magnet Synchronous Motor (PMSM) as actuating motor, through building the system simulation model and experiment platform, mainly focus on the issue of inertia identification of the AC servo system.Firstly, the significance of the inertia identification and its novel development trend are introduced briefly in this thesis. Then, based on field-oriented control theory and basic identification theory, it is noticed the fact that inertia and torque change will deteriorate the AC servo system'dynamic performance, an inertia identification scheme is analyzed and studied. After the theory analysis, the control system including inertia identification sub-system simulation model is set-up using Matlab/Simulink, then the inertia identification scheme is verified. After that the open architecture motion control and testing system including servo motor and driver, motion control card and personal computer is introduced. In the personal computer, the speed-controller is designed, using the speed information and torque information, the inertia identification software is also designed. After all of this, considering the two-mass load connected with plastic mechanism, the inertia identification scheme and simulation model are improved. Finally, in the hardware platform, to obtain the mechanical natural-oscillation frequency, a fast fourier transform(FFT) software is also designed. The FFT software is helpful not only to offer the frequency to easily identify the parameter of servo system, but also to design the notch filter to prevent the resonance occurred. A proposal for further study is also put forward.