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Full-Text Articles in Controls and Control Theory
A Lithium Battery Current Estimation Technique Using An Unknown Input Observer, Daniel Cambron
A Lithium Battery Current Estimation Technique Using An Unknown Input Observer, Daniel Cambron
Theses and Dissertations--Electrical and Computer Engineering
Current consumption measurements are useful in a wide variety of applications, including power monitoring and fault detection within a lithium battery management system (BMS). This measurement is typically taken using either a shunt resistor or a Hall-effect current transducer. Although both methods have achieved accurate current measurements, shunt resistors have inherent power loss and often require isolation circuitry, and Hall-effect sensors are generally expensive. This work explores a novel alternative to sensing battery current by measuring terminal voltages and cell temperatures and using an unknown input observer (UIO) to estimate the battery current. An accurate model of a LiFePO4 …
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators, Joshua L. Evans
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators, Joshua L. Evans
Theses and Dissertations--Electrical and Computer Engineering
Attitude control remains one of the top engineering challenges faced by small satellite mission planning and design. Conventional methods for attitude control include propulsion, reaction wheels, magnetic torque coils, and passive stabilization mechanisms, such as permanent magnets that align with planetary magnetic fields. Drawbacks of these conventional attitude control methods for small satellites include size, power consumption, dependence on external magnetic fields, and lack of full control authority. This research investigates an alternative, novel approach to attitude-control method for small satellites, utilizing the noncommutative property of rigid body rotation sequences. Piezoelectric bimorph actuators are used to induce sinusoidal small-amplitude satellite …