Chek-Sing Teo

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The scanning accuracy of piezoelectric mechanisms over broadband frequencies is limited due to inherent dynamic hysteresis. This phenomenon has been a key bottleneck to the use of piezoelectric mechanisms in fast and precision scanning applications. This paper presents a systematic model identification and composite control strategy without hysteresis(More)
Ultrasonic motors used in high-precision mechatronics are characterized by strong frictional effects, which are among the main problems in precision motion control. The traditional methods apply model-based nonlinear feedforward to compensate the friction, thus requiring closed-loop stability and safety constraint considerations. Implementation of these(More)
Jerk derivative feedforward control is proposed and used in recent literatures. However, such feedforward control scheme is restricted to the minimum-phase system which has constrained static gains in the flexible modes. This paper presents a novel form of feedforward controller for a wider class of flexible motion systems, even to be non-minimum phase, as(More)
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