Project Director

Loveless, Daniel

Department Examiner

Ofoli, Abdul


Dept. of Electrical Engineering


University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)


Small satellites such as CubeSats operate under environmental constraints that are outside of typical commercial specifications. Such constraints include the ability to operate over an extended temperature range and during exposure to ionizing radiation. Nevertheless, commercial technologies are being implemented in CubeSat spacecraft because of the low-cost, low-power, and space savings requirements often achievable with advanced microelectronics [1]. Due to flexibility and the ability to handle uncertainty, fuzzy logic is viable for satellite control while meeting the strict design requirements of a CubeSat. This work evaluates the response of fuzzy control logic to ionizing radiation and compares the response to that of conventional systems. Fuzzy logic operates on multiple truth values which vary within the range of 0 and 1, as opposed to Boolean logic’s precise, two-variable system. Fuzzy systems utilize “if-then” statements, known as membership functions. These allow for terms such as “moderately” or “slightly,” to be utilized, permitting flexibility within the system. As such, fuzzy logic shows promise in robotics and mechanical control systems due to the ability to handle uncertainty and non-linearity. Thus, fuzzy logic electronics are a candidate for small satellite control mechanisms, creating the potential for radiation hardened control systems that take advantage of the low-power and space savings achievable by modern electronics technologies. A common effect of ionizing radiation is single event effects (SEEs). SEEs generally result in erroneous transient behavior following the interaction of single ionizing particles with semiconductors. Little is known about the response of fuzzy logic systems to such effects. This work aims to evaluate the effects of SEE on a fuzzy logic small satellite attitude controller, describe the mechanisms of vulnerability, and compares the response to standard controller designs.


B. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Science.




Fuzzy logic; Fuzzy systems; Artificial satellites


Fuzzy logic; Space; Ionizing radiation; PID controllers; Electronics; Fuzzy controllers


Electrical and Computer Engineering

Document Type



45 leaves




Under copyright.