Comparative Implementations of a Hydraulic-Contorol Fatigue Testing Machine

Abstract

Adaptive feedforward control and self-organizing fuzzy control are comparatively implemented to a hydraulic-control fatigue testing machine.The experiments are tested at 0.1-10 Hz sinusoidal positions and with force commands.Since adaptive feedforward control requires on-line parameter identification which needs increased computer time, its testing frequency is limited.However, adaptive feedforward control has combined pole-zero and phase cancellations.The experimental results prove their excellent tracking performance.Self-organizing fuzzy control can reduce the computer load to enlarge the testing frequency range.In addition, it has a learning mechanism to adjust the fuzzy rule for various operating conditions.Although the control response of self-organizing fuzzy control cannot achieve perfect tracking, its peak-peak magnitude can always match the command magnitude very well.