Browsing by Author "Demir, Didem Fatma"

Now showing 1 - 3 of 3

Restricted
Çalışmaları ve sosyal yaşamı ile Halet Çambel
(Bilkent University, 2015) Mola, Eyüp Ertuğrul; Arman, Deniz Dicle; Demir, Didem Fatma; Cemil Sabır, Ahmet
Open Access
Design, manufacturing, and rough terrain analysis of a collision resilient foldable, adjustable wheeled miniature robot: FAWSCY
(2021-01) Demir, Didem Fatma
FAWSCY: Foldable Adjustable Wheeled Stringy Clumsy Robot is a foldable, collision resilient, adjustable wheeled robot which can run through diﬀerent ter-rains and inclined surfaces, to inspect areas which are unavailable to humans due to dimensional limitations or hazardousness level; to attend search and rescue missions to cover more area in a shorter duration and to be a part of somatic activities with elders and kids. Hence, it is desired to be non-harmful to itself and its environment in case of any collisions or falls, and persistent on its run under various conditions and terrains as any insect or lizard can. FAWSCY is an incremental work that till attaining its ﬁnal version, several legs and wheels; and electronic components and their combinations are investi-gated. First, c-legs are tested due to its advantages on rough terrains, yet they lack sensor implementation by its constant oscillatory movement. Then ninja stars are tested the robot yet they are so rigid that they sunder from the body in presence of a collision or undesired tracking. Afterwards, the bellow design is modiﬁed to be enforced as a wheel and it is the most promising wheel conﬁgu-ration since it can damp all longitudinal, lateral and vertical forces during the impact of a collision and fall. Also, it has appreciable rough terrain performance. However, as well as being soft it is also quite strong that it cannot be controlled for diﬀerent length conﬁgurations for a miniature untethered scale. Therefore, it is not applicable for FAWSCY. On its ﬁnal adjustable wheel, a novel wicker modular wheel design which exhibits similar behaviour with the bellow design, and its adjusting mechanism are proposed. On the other hand, Raspberry Pi is chosen to be the main processor, and by experiments and investigation through diﬀerent motors, sensors and control strategies, a two part single board design is ﬁnalized. The body of FAWSCY is also kirigami-inspired and formed by foldable sheets to cover and maintain integrity of its parts and components. After the design is completed, its performance and capabilities are assessed. First, its indoor run performance, wheel adjustment mechanism, collision resilient properties, obstacle scaling and response to inclination are investigated. The robot is assessed to be suitable for indoor environments, stairs and inclinations without getting disintegrated and harming other living subjects. Then, rough terrain experiments are conducted which resulted in success on grass, gravel and soil terrains with diverse wheel length conﬁgurations.
Open Access
Effects of linear filter on stability and performance of human-in-the-loop model reference adaptive control architectures
(ASME, 2017) Yousefi, Ehsan; Demir, Didem Fatma; Sipahi, R.; Yücelen, T.; Yıldız, Yıldıray
Model reference adaptive control (MRAC) can effectively handle various challenges of the real world control problems including exogenous disturbances, system uncertainties, and degraded modes of operations. In human-in-the-loop settings, MRAC may cause unstable system trajectories. Basing on our recent work on the stability of MRAC-human dynamics, here we follow an optimization based computations to design a linear filter and study whether or not this filter inserted between the human model and MRAC could help remove such instabilities, and potentially improve performance. To this end, we present a mathematical approach to study how the error dynamics of MRAC could favorably or detrimentally influence human operator's error dynamics in performing a certain task. An illustrative numerical example concludes the study.