Author

Jessica Hamer

Date of Award

2025

Document Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Mechanical and Aerospace Engineering

Committee Chair

Farbod Fahimi

Committee Member

Chang-kwon Kang

Committee Member

Howard Chen

Research Advisor

Farbod Fahimi

Subject(s)

Signal processing--Mathematics, Numerical differentiation, Sliding mode control

Abstract

This thesis explores the performance of higher-order sliding mode differentiators applied to sensor signals under varying sampling rates and switching functions. Two differentiator designs are evaluated: a hybrid algorithm that combines a super-twisting algorithm with a linear observer, and a fixed-time higher-order sliding mode differentiator. Each was tested on a physical sensor testbed using position data from a servomotor and electronic compass. The differentiators were implemented in a ROS2 environment, and their estimates were evaluated by obtaining the minimum and maximum position and velocity values, as well as analyzing graphs to capture the nature of the algorithms' noise reduction. The results indicate that the sampling rate and switching functions have a significant impact on performance. These findings provide insight into the robustness of higher-order differentiators for real-time signal processing.

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