Nonlinear Robust Bias Observer for MEMS Gyros Using Noninertial Attitude Sensor Measurement

Abstract

In robotic applications, the dynamics sensitivities of commercial-grade micro-electro-mechanical system (MEMS) gyros often exhibit uncertainties that cannot be accurately modeled by linear drift. To address the estimation of these uncertain biases, we propose a novel nonlinear robust bias observer (NRBO) in this article. Unlike existing nonlinear observers for attitude and gyro bias, our proposed method incorporates a dynamics-sensitive gyro bias estimation approach, achieved through the synthesis of the attitude-angular rate nonlinear dynamic coupling (AARNDC) term and the attitude-linear coupling (ALC) term. We highlight the potential advantages of our proposed method, including the asymptotic stability of the NRBO and its robustness against MEMS gyro bias instability, enabled by a rational design of the AARNDC and ALC terms. In addition to gyro bias estimation, we present the attitude estimation within the NRBO framework. Field experimental results, conducted with a cable-driven parallel robot, demonstrate the robustness of the proposed NRBO against bias instability measurement noise. Moreover, the results Manuscript