Compensation of the Influence of Linear Acceleration on the Parameters of a Frame Micro Optoelectromechanical Angular Velocity Transducer

This study discusses the problem of reducing the influence of external destabilizing factors on microelectromechanical angular velocity transducers. It reveals that for measurements of small angular velocities of the order of a few to tens of microradians per second, micro optoelectromechanical transducers that contain optical readout units are preferable to use. The effect of linear acceleration on the characteristics of a frame micro optoelectromechanical angular velocity transducer with two optical readout channels is analyzed. We consider two methods of angular velocity measurement error compensation when the frame micro optoelectromechanical transducer is under the influence of linear acceleration. The two compensation methods implement amplification factor control and force feedback, respectively. The readout unit, based on the optical tunnel effect and used for precision measurement of the amplitude of oscillations of the sensing element, is experimentally investigated; a function of converting the amplitude of oscillations of the sensing element into voltage is obtained. The possibility of forming transducer output signals, which are proportional to angular velocity and linear acceleration, is presented. The dependences of changes in the amplification factor on the zero off set voltage, proportional to the acting linear acceleration, are presented for different ranges of angular velocities. A system, consisting of a low-pass filter (LPF), a proportionalintegral regulator, and an additional pair of comb-type electrostatic actuators, is proposed for compensating the force effect of a destabilizing linear acceleration. Additional actuators are arranged perpendicular to the actuators that excite the primary oscillations. The measurement error of angular velocity when using the two methods of compensation, respectively, has been estimated. The proposed technical solutions enable to increase the accuracy of angular velocity measurements by micro optoelectromechanical transducers used in navigation and orientation systems of unmanned aircrafts of various types.