Assessment parameters of fractional order capacitor of piezo-patch harvester located on a multicopter

Parameters of an EH system with a supercapacitor and piezo harvester located on a single arm of the UAV copter have been assessed in this manuscript. In order to check the efficiency of this system, firstly the electromechanical model of a piezo-harvester with homogenized material has been considered as well as mechanical parameters of the macro-fiber composite in the form of mode shapes and bending strains for different duty cycles of the PWM signal applied to a brushless DC motor have been determined. The obtained simulations results allow to determine a proper location of the piezo harvester on the considered structure and assess its electrical parameters. In order to do it, the electro-elastic fractional order model of the piezo composite in modal coordinates has been analyzed. The obtained experimental results of the EH system connected with the SSHI circuit allow to verify numerical results and indicated that the proposed approach can be used to power small devices located on the UAV platform with low power demand under certain conditions

Sliding mode control of the MAV with used eralier calculated aerodynamical forces and moments

Typowe sterowanie mikrosamolotem odbywa się w klasyczny sposób z wykorzystaniem powierzchni nośnych płatowca. Czasami ze względu na ograniczone możliwości konstrukcyjne MAV i postawione jemu wymagania należy zmienić sposób sterowania MAV a tym samym zmienić sposób powstawania wirów krawędziowych na krawędzi natarcia samolotu. W poniższym artykule w pierwszym etapie zostanie rozpatrzony model MAV z wysuwaną barierą mechaniczną na krawędzi natarcia. W drugim zaś zostanie zaprojektowane prawo sterowania barierą w oparciu o regulator ślizgowy ( ang. sliding controller). Uzyskane w ten sposób badania symulacyjne zostaną ze sobą porównane w celu wyciągnięcia istotnych wniosków.Nowadays control of MAV progressed in typical way by surface lift vehicle. Sometimes in relative limited possibility structural we may changed way control of MAV. Simultaneously we have changed way appear leading edge vortexes on vehicle. The paper was divided on two stage. In the first step was consider mathematical model of MAV with movable bar mechanical on leading edge. In second step was designed control law for control movable mechanical bar based on sliding controller. Obtained results in simulation was collected and compared

The influence of the piezoelements placement on the active vibration damping of smart truss

Vibrations control in truss structures reaches a great practical interest, mainly in modern structures of huge space vehicles and aircrafts. Two demands essences are required in design of such structures. The first is the excellent dynamic behavior, in order to guarantee the stability of the structure and high precision pointing. The second is the necessity to obtain light structures, in order to reduce the cost. However, these two requirements are often contradictory, because light structures have low degrees of internal damping, which hinders the accuracy requirements. These difficulties can be overcome by applying recently developed advanced materials, as for instance piezoelectric materials. Several researchers have proved that piezoelectric material can effectively counteract the vibrations. Appropriate assurance active damping of these vibrations can be achieved by optimal location of the piezo elements in the structure

Aktywny układ sterowania drganiami przestrzennej prętowej konstrukcji mechanicznej

The active vibration control system for 3D mechanical structures is presented in the paper. The steel space framework which consists of 126 steel bars and 44 aluminium joints is a subject of our investigations. It is equipped in two piezoelectric stacks which are a part of chosen vertical bars in a plane X-Z. Bars, joints and piezo-stacks have got glue connections. The mathematical model was decoupled to change Two Input Two Output (TITO) system into two Single Input Single Output (SISO) systems. Such approach allowed us to design simple control laws with help of computer simulation procedure. In the last chapter the investigations on the laboratory stand of the active vibration control system with local controllers PD are described. Experimental results have proved that these PD controllers work good increasing the damping level. Additional damp in the system causes the excellent vibration reduction for the whole mechanical structure.Aktywne sterowanie drganiami przestrzennej konstrukcji prętowej zostało przedstawione w poniższym artykule. Obiektem badań jest przestrzenna konstrukcja prętowa zawierająca 126 elementów prętowych, 44 aluminiowe węzły oraz dwa piezostosy. Wspomniane piezoelektryczne aktuatory stosowe zostały wklejone do konstrukcji w wybranych pionowych elementach prętowych w płaszczyźnie X-Z. Globalny model matematyczny obiektu jest układem o dwóch wejściach i dwóch wyjściach (TYTO), który na potrzeby projektowania praw sterowania został rozprzężony na dwa podukłady o jednym wejściu i jednym wyjściu (SISO). Projektowanie praw sterowania zostało przeprowadzone na drodze badań symulacyjnych w środowisku Matlab. W końcowej części artykułu opisano badania eksperymentalne wraz z zaprojektowanymi lokalnymi regulatorami PD. Wyniki tych badań udowadniają, że wspomniane regulatory PD zwiększają poziom tłumienia. Tym samym dodatkowe tłumieniem które pojawiło się w układzie powoduje znakomitą redukcję drgań całej konstrukcji mechanicznej

Modelowanie pasywnego układu zawieszenia siedziska

In this paper, a model of the passive seat suspension system is designed. To verify the model the excitation signals are modelled by using generator embedded to Simulink software. Additionally, the excitation signal is filtered with the use of the Butterworth filters. The vibroisolation properties of the system are calculated on the basis of the ratio transmissibility of the vibration. The investigations proved that the designed system is correctly modelled and the system damps the vibration speciously in the most dangerous frequency range up to 20 Hz.W artykule przedstawiono model pasywnego układu zawieszenia siedziska operatora autobusu na przykładzie siedziska firmy ISRI. Na potrzeby badań losowe sygnały wymuszenia zostały zamodelowane w środowisku Matlab/Simulink. Dodatkowo,na potrzeby badań, sygnały wymuszenia zostały przefiltrowane z wykorzystaniem filtru Butterworth. Właściwości wibroizolacyjne układu zostały wyznaczone na podstawie kryterium współczynnika przenoszenia drgań. Badania symulacyjne wykazały tłumienie drgań przez układ szczególnie w najbardziej niebezpiecznym zakresie częstotliwości do 20 Hz

PID controllers design applied to positioning of ball on the Stewart platform

The paper presents the design and practical implementation of PID controllers for a Stewart platform. The platform uses a resistance touch panel as a sensor and servo motors as actuators. The complete control system stabilizing the ball on the platform is realized with the Arduino microcontroller and the Matlab/Simulink software. Two processes required to acquire measurement signals from the touch panel in two perpendicular directions X and Y, are discussed. The first process includes the calibration of the touch panel, and the second process - the filtering of measurement signals with the low pass Butterworth filter. The obtained signals are used to design the algorithm of the ball stabilization by decoupling the global system into two local subsystems. The algorithm is implemented in a soft real time system. The parameters of both PID controllers (PIDx and PIDy) are tuned by the trial-error method and implemented in the microcontroller. Finally, the complete control system is tested at the laboratory stand

Mechanical and electrical impedance matching in a piezoelectric beam for Energy Harvesting

A piezoelectric beam is one of transducers for energy harvesting. It provides easy implementation and good performance in changing mechanical stress into electric voltage. In order to maximize output power, it is important to provide mechanical and electrical impedance matching. In the paper the authors proposed a methodology which allows to find values of lumped elements in an electromechanical model after completing appropriate measurements. Due to linear equations, it is possible to model a beam in both mechanical and electrical ways, and match the best load depending of frequency. The proposed model of a piezoelectric cantilever shows a potential use of these devices in micro scale as a cantilever which is a part of a silicon structure. Moreover, in the paper, the authors discuss mechanical aspects of using a weight as the way to tune the piezoelectric beam to a specific frequency. The electrical aspect of matching the source impedance with load, which is based on an electrical model of a piezoelectric transducer, is also presented. In the paper a mathematical model was verified by an experiment in which a laboratory stand equipped with a vibration generator, a piezoelectric energy harvester and acceleration sensors was used