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Abstract:
Piezoeleclric
actuators often work in a close-loop feedback position control
system due to hysteresis. The objec-tive is to make an actuator
self-sense its output force and dis-placement \vithout using
extra sensors. The technique is termed self-sensing
actuator/actuation (SSA). A compound circuit is proposed to
voltage-drive the piezoelectric actuator and get the resuiting
charge concurrently. Based on the circuit, the un-stressed
actuator can self-sense its free strain. If the actuator is
externally stressed, an Observer is construcied to estitnate the
actuator's stress and strain state. The observer-based
self-sensing approach depends on tlie fact that the electric
field is controllable and the electric displacement is
measurable. In order to cornpensate hysteresis, voltage versus
charge relation is modeled using generalized Maxwell slip (QMS)
model, and the observer is improved to a nonlinear one. The
observer-based SSA approach successfiilly bypasses the impedance
mismatch-ing problem bothering the bridge-based SSA approach.
The self-sensed average strain of piezoelectric bimorph is
coincident with the tip displacement measured by proximitor.
Key words:Piezoceramics
Actuator State observer/Self-sensing actuator
CLC No: TP274.5 TH39
国家自然科学基金(69774020)和教育部博士学科点专项科研基金资助项目(98014106). Received 20010522,
received in revised form 20011010
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