On High-Precision Large-Range Resonant-Amplified Scanning with Limited Range Actuation

Compliant mechanisms have found applications in high-precision micro-measurement, microfabrication, micro-manipulation, and other areas. These mechanisms have inherent advantage of being highly precise, backlash-free, low energy consuming, and frictionless and hence durable. However, typical range of motion and speeds with these mechanisms are limited because of large deformation nonlinearities and complex dynamics. Furthermore, achieving higher range of motion with much lower stroke non-collocated actuator is another challenge. Displacement amplifying compliant mechanisms, found in the literature, provides solution for higher range with lower stroke actuation. However parasitic errors are high, complex structure with several moving masses makes their usage in dynamic applications (higher speeds) difficult. We propose, in this paper, alternate method using resonant displacement amplification using simple double parallelogram compliant mechanism (DPCM) toward higher but fixed speed applications. With limited stroke of actuation, we develop control algorithms to maintain a stable limit cycle. Parametric study using lumped mass model offers pathways for design decisions and unfolds interesting results. Experimental results validate the proposed method but point to limitations of the lumped mass model.