| Summary: | 碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 92 === The purpose of the study is to reduce the output torque ripple of harmonic drive system by a control structure, which includes feedback controller and feedforward compensator. This control structure can improve transient response and tracking performance, and can eliminate the friction, low and high frequency disturbance of the system. Also, it can produce good torque response in the system and exactly cancel torque ripple coming from transmission error.
Internal model control is designed on frequency domain, which used closed-loop model-base control approach to decide close-loop performances of the system, It can provide the system to produce ideal torque response systematically. Iterative learning type feedforward compensator, adaptive feedforward cancellation and DOB_based adaptive feedforward cancellation are three kinds of feedforward compensators in this study. Based on signal modeling and signal restoration, these models can get Fourier coefficients from periodic disturbance or error signal, and use coefficients to get appropriate feedforward control signal. The outcome from the research shows the stability and convergent speed of three compensators。
In the experiment, we use FHA-SP, a joint product by Japan HarmonicDrive Corporation and German Aerospace Center(DLR). It includes a harmonic drive gear and torque sensor, to drive the 1-link robot manipulator. For implement controls, we combine TI’s DSK and an expansion board as our control kernel; besides, we use C language and hardware description language(VHDL) to take for developing tool. The results of the study evidence the feasibleness of this control structure.
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