Low to medium level image processing for a mobile robot

The use of visual perception in autonomous mobile systems was approached with caution by mobile robot developers because of the high computational cost and huge memory requirements of most image processing operations. When used, the image processing is implemented on multiprocessors or complex and expensive systems, thereby requiring the robot to be wired or radio controlled from the computer system base

LIPIcs, Volume 248, ISAAC 2022, Complete Volume

LIPIcs, Volume 248, ISAAC 2022, Complete Volum

Spatiotemporal Effects of Transport and Network Topology in Biological Systems

Emergent biological phenomena, although observed experimentally, are often not easily characterized or understood. Biological systems are often comprised of many interacting components, which may yield highly complex dynamics. A thorough understanding of these systems often requires a multi-faceted approach involving both experimental and computational techniques. Computer simulation allows for precise definition of system components and facilitates a wider exploration of the system parameter space, often leading to accelerated scientific discovery. In this thesis, we apply stochastic simulation methods to characterize the spatiotemporal behavior of three distinct biological systems. We first explore the role of spatial confinement and diffusion in a bistable reaction network with positive feedback. We find that confined systems with high molecular mobility promote the active steady state, and stochastic switching occurs unidirectionally by nucleation and growth of single active clusters. The results provide a general framework for studying geometry and diffusion in positive feedback networks, and suggest that confinement can be used to initiate the formation of localized active clusters of molecules that then propagate to activate a system. Next, we study transport properties of single molecular motors traversing cytoskeletal networks with random filament configuration. We find that systems containing few, long filaments exhibit slow and highly variable transport. Particular filaments are capable of having an outsized influence on first-passage times by acting as lynchpins that transport motors to and from regions of the system that act as traps that promote extended occupancy. Finally, we use two distinct models to explore the dynamics of protein organization along an actomyosin ring. We find that a positive feedback circuit can be used to establish and maintain polarized protein distributions, and clustering is suppressed by endocytosis and fast diffusion. In the absence of positive feedback and dissociation from the ring, we find that slow association of large patches leads to clustered distributions of higher variability. These results suggest that homogeneous spatial distribution of proteins in mature actomyosin rings may depend on frequent association of small protein clusters. Taken collectively, these findings suggest that stochastic computational modeling can facilitate the elucidation of key mechanistic features of emergent biological phenomena

PAC: A Novel Self-Adaptive Neuro-Fuzzy Controller for Micro Aerial Vehicles

There exists an increasing demand for a flexible and computationally efficient controller for micro aerial vehicles (MAVs) due to a high degree of environmental perturbations. In this work, an evolving neuro-fuzzy controller, namely Parsimonious Controller (PAC) is proposed. It features fewer network parameters than conventional approaches due to the absence of rule premise parameters. PAC is built upon a recently developed evolving neuro-fuzzy system known as parsimonious learning machine (PALM) and adopts new rule growing and pruning modules derived from the approximation of bias and variance. These rule adaptation methods have no reliance on user-defined thresholds, thereby increasing the PAC's autonomy for real-time deployment. PAC adapts the consequent parameters with the sliding mode control (SMC) theory in the single-pass fashion. The boundedness and convergence of the closed-loop control system's tracking error and the controller's consequent parameters are confirmed by utilizing the LaSalle-Yoshizawa theorem. Lastly, the controller's efficacy is evaluated by observing various trajectory tracking performance from a bio-inspired flapping-wing micro aerial vehicle (BI-FWMAV) and a rotary wing micro aerial vehicle called hexacopter. Furthermore, it is compared to three distinctive controllers. Our PAC outperforms the linear PID controller and feed-forward neural network (FFNN) based nonlinear adaptive controller. Compared to its predecessor, G-controller, the tracking accuracy is comparable, but the PAC incurs significantly fewer parameters to attain similar or better performance than the G-controller.Comment: This paper has been accepted for publication in Information Science Journal 201

LIPIcs, Volume 274, ESA 2023, Complete Volume

LIPIcs, Volume 274, ESA 2023, Complete Volum

Design and application of a wireless torque sensor for CNC milling

A Smart Machining System for Computer Numerical Control (CNC) Milling continually adjusts the cutting process parameters to optimize for cutting tool life and material removal rate. The system depends on sensors to gather information from the machine during cutting, but commercially available sensors detract from the effectiveness of the cutting system by lowering the system stiffness. This research focuses on the development of the electronics for a Smart Tool Holder (STH) and potential applications such as measurement of mechanical cutting power and suppression of chatter. The STH is a standard milling tool holder modified to hold a torque strain gauge bridge, a thermocouple and a Bluetooth radio transmitter. The STH is meant to overcome some of the different limitations imposed by bed dynamometers, microphones and spindle power sensors without reducing the system stiffness. Comparison of the mechanical power estimates from the STH and a conventional power sensor showed 10% difference

LIPIcs, Volume 244, ESA 2022, Complete Volume

LIPIcs, Volume 244, ESA 2022, Complete Volum