In this paper, we present the design and construction of a multi-robot system in order to carry out the transportation of objects. We designed, simulated, implemented and compared two intelligent ...controllers for two differential mobile robots used for objects transportation. The control laws used were the Parallel Distributed Controller (PCD) with two rules and a fuzzy PD (Proportional Derivative) controller with 9 rules of Takagi-Sugeno type. The experimental setup uses two differential mobile robots for transporting a rigid object; this system was modeled as one, using the instantaneous center of rotation, which allowed us to determine the necessary speed for each robot. For physical implementation were built and instrumented two mobile robots using a Gumstix computer to carry out the digital signal processing. The synchronization of two mobile robots was accomplished by monitoring the implemented algorithms. In the object transportation, the user sets the desired trajectory indicating the start and end point within the system workspace. Finally, in the results section we present a good correspondence between simulation and experimental results, and it was observed that the PDC controller has better performance to carry out the transportation of objects regardless of the initial conditions or reference system.
This paper reports a fuzzy differential equations approach for the modeling of initial condition uncertainty for a proportional derivative closed-loop control of a direct current motor. Uncertainties ...are considered on the precision of the sensing devices installed on a driver. The closed-loop system is designed for a plant modeled with fuzzy differential equations. Satisfactory analytic and numerical results for the position regulation problem for ideal case and also considering perturbed initial conditions are reported.
This paper presents the fabrication and characterization of CdS thin film solar cells synthesized by chemical bath deposition using acid as a complexing agent with pH values between 10.1 and 11.3. We ...studied the influence of pH control of the reaction solution on the structural and optical properties of chemically deposited CdS thin films. Different films thicknesses of CdS were deposited onto a glass substrate. The structural surface morphology of as-deposited CdS thin films was characterized by scanning electron microscope, x-ray diffraction, profilometer, and ultraviolet–visible spectroscopy. The investigation of the effect of the synthesis method on the change the ammonium hydroxide by buffer pH 11 contributed in increases the growth kinetics, resulting thicker films. The films show high absorption and band gap values were found from 2.38 to 2.58 eV with different time deposition. The results are quite appreciable and high efficiency can be obtained from these CdS thin-film solar cells.
U radu je razvijen postupak sinteze proporcionalno-derivacijskog regulatora za upravljanje istosmjernim motorom s neizrazitim (engl. fuzzy) početnim uvjetima zasnovane na neizrazitim diferencijalnim ...jednadžbama. Pritom je uzeta u obzir nesigurnost određena mjernom preciznošću senzora. U predloženom postupku se zatvoreni regulacijski krug dizajnira korištenjem neizrazitih diferencijalnih jednadžbi. Primjenom projektiranog regulatora na probleme pozicioniranja u idealnom slučaju te u slučaju koji uzima u obzir perturbirane početne uvjete ostvareni su zadovoljavajući analitički i numerički rezultati.
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