Design and control of a novel asymmetrical piezoelectric actuated microgripper for micromanipulation

Microgripperis animportant tool in highprecisionmicromanipulationtask, whichdirectly affects the quality and efficiency of micromanipulation.Thispaper presents the design and control of a novel asymmetrical microgripperdriven by a piezoelectric(PZT)actuator.Thedevelopedmicrogripperis designedasanasymmetrical structurewithjust onemovablejaw, soit hasthe advantagesofnodensemodeandfixed locatingdatumcomparedwiththesymmetricalmicrogripperwithtwomovablejaws. The mainbody of microgripperis a compact flexure-based mechanicalstructure witha three-stage amplification mechanism. Basedon the designed structure, large-range, robustandparallelgraspingoperationcanberealized.Thecharacteristicsanalysesofthe developedmicrogripperarecarriedoutbyfiniteelementanalysis(FEA). Aposition-force switching control strategy is utilized to regulate the position and grasping force of movablejaw. Discrete-time slidingmodelcontroller(DSMC) is designedto controlthe positionandgraspingforceofgraspingjaw. Experimentalstudiesareconductedandthe resultsshowthatthemicrogripperexhibitsgoodperformanceandhighprecisiongrasping operationscanberealizedthroughthedevelopedcontrolstrategy.