Mekatronik Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/255
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Article Citation - WoS: 4Citation - Scopus: 4String Stability Under Actuator Saturation on Straight Level Roads: Sufficient Conditions and Optimal Trajectory Generation(Ieee-inst Electrical Electronics Engineers inc, 2022) Bingol, Hilal; Schmidt, Klaus WernerThe heterogeneity of vehicles is an important factor when realizing cooperative adaptive cruise control (CACC) in practice. Specifically, it has to be considered that platoons generally consist of vehicles with both different dynamic properties and actuator limits on the engine and braking force, which is expected to have a negative impact on important properties such as string stability. Accordingly, the subject of this paper is the preservation of string stability for CACC in heterogeneous vehicle strings with potential actuator saturation. To this end, the paper formulates a velocity-dependent force bound that enables the derivation of sufficient conditions for preserving string stability during velocity changes of heterogeneous platoons. These conditions are then used for the analytical computation of trajectories for time-optimal velocity changes. The formal results of the paper are supported by an illustrative simulation study.Article New Model for Liquid-Based Rapid Prototyping With a Scanning Lorentz Beam(Elsevier Gmbh, 2021) Arpali, C. CaglarIn this work, a new model is proposed to examine the effect of scanning Lorentz beam on a liquid based rapid prototyping scheme. The interaction of a Lorentz laser beam with a photocurable resin is analysed for different kinds of processing parameters such as beam power, beam size, scan speed, cure depth, width of the cured region and critical radiant exposure. The penetration depth profile of curing is obtained while the beam propagates inside the resin. It is shown that the proposed laser scanning model can be used to estimate the depth profile of the cured region that is treated for a certain amount of critical exposure. The Lorentzian beam generates fine and narrow hatch structures along the scan direction. This distinct ability facilitates the development of a low resolution process for fabricating complex patterns.Article Citation - WoS: 5Citation - Scopus: 6Multi-Objective Trajectory Planning for Slung-Load Quadrotor System(Ieee-inst Electrical Electronics Engineers inc, 2021) Ergezer, HalitIn this article, multi-objective trajectory planning has been carried out for a quadrotor carrying a slung load. The goal is to obtain non-dominated solutions for path length, mission duration, and dissipated energy cost functions. These costs are optimized by imposing constraints on the slung-load quadrotor system's endpoints, borders, obstacles, and dynamical equations. The dynamic model of a slung-load quadrotor system is used in the Euler-Lagrange formulation. Although the differential flatness feature is mostly used in this system's trajectory planning, a fully dynamic model has been used in our study. A new multi-objective Genetic Algorithm has been developed to solve path planning, aiming to optimize trajectory length, mission time, and energy consumed during the mission. The solution process has a three-phase algorithm: Phase-1 is about randomly generating waypoints, Phase-2 is about constructing the initial non-dominated pool, and the final phase, Phase-3, is obtaining the solution. In addition to conventional genetic operators, simple genetic operators are proposed to improve the trajectories locally. Pareto Fronts have been obtained corresponding to exciting scenarios. The method has been tested, and results have been presented at the end. A comparison of the solutions obtained with MOGA operators and MOPSO over hypervolume values is also presented.