Optimal design and test of double elastic plate based fast tool servo

A double elastic plate based Fast Tool Servo (FTS) was designed to fabricate non-rotational symmetrical micro-structured surfaces using diamond turning method. Then, the performance of the FTS was tested. According to constrain conditions, the analytical expression for the stiffness of elastic plates was derived and the calculation method for the maximum Von Mises stress of the plates was also given. Based on the specification of the FTS, the structural parameters of the elastic plates were optimized and a FTS was machined in accordance with the parameters mentioned above. Finally, a control system for the FTS was established, and the static and dynamic characters were tested. The test results show that the stiffness of the FTS is 53 N/μm, the motion resolution is 3 nm, and the travel range can reach to 20 μm. Furthermore, the FTS can offer the static following error better than 4 nm, the open loop bandwidth of 2 kHz and the fundamental frequency up to 3 kHz. The test results not only demonstrate the correctness of the design method, but also indicate that the double elastic plate based structure is a good choice for the micro-displacement units with high stiffness and high precision.