Design and control of a one-dimensional stage based on elastomeric bearing technology

Precision motion control is vital for modern industrial applications. A controlled stage with both fast positioning and relative vibration suppression can improve either inspection efficiency or product quality. Recently, with the advancing in elastomer technology and utilizing the stiffness anisotropy, it is possible to integrate rubbers for providing both bearing and restoring forces in stage design for reducing the size and enhancing the dynamic performance. In this paper, a single-degree-of-freedom precision stage containing four silicone elastomeric bearings is designed and realized. Essential material characterizations are performed for quantifying the elastic and viscoelastic properties of materials and the system dynamics are modelled with time- and frequency-varying stiffness. A closed-loop control system comprising a voice coil motor as the actuator and a capacitance probe as the feedback position sensor is then realized. Here the Integral Sliding Mode controller is used in associated with the stage. In comparison with a previous compliant mechanism-based design, the stage size is reduced, the positioning stroke is increased from 101 μm to 139 μm, and the bandwidth is increased from 29 Hz to 350 Hz.