Modal coupling error suppression in micromachined gyroscopes by UV laser trimming

This paper focuses on a structural suppression method of modal coupling error in micromachined gyroscopes by UV laser trimming. A micromachined gyroscope which had a slanted suspension beam was adopted as an example in the experiment. The formation mechanism of modal coupling error and operation principle of structural suppression method were proposed. Laser trimming method was implemented on the micromachined gyroscope. The experimental results demonstrate a successful suppression of modal coupling errors for the proposed architecture with more than an order of magnitude, mainly appearing in the form of stiffness nonidealities. Furthermore, mass trimming would be adopted as a fine compensation strategy to rebalance the modal vibration.