Attitude Estimation for Drilling Tools Based on Robust State-Constrained Zonotopic Observer

Attitude estimation for drilling tools is critical in drilling engineering. However, existing state estimation studies are insufficient in bounded constraint utilization, uncertainty description and disturbance robustness. This paper proposes a robust state-constrained zonotopic observer where bounded constraints are augmented and measurement disturbance bounds are adaptively estimated by residuals. Then, the theoretical analysis proves that state constraints can reduce the size of the error set. Particularly, the error boundedness and the disturbance robustness are guaranteed through state range constraints. Finally, simulation and experimental results illustrate that the proposed method makes full use of constraints and has higher estimation accuracy and stronger disturbance robustness than existing methods.