Papers by Keyword: PWM

Abstract: The goal of this work is to use MATLABSimulink to create a simulation of a DC-to-DC boostconverter it, utilizing SPMC topology that is a matrixconverter with only one phase. With the outputboosted more than that the fluctuations are quiet high.In this project work, we have tried to boost up theoutput to five times after keeping the fluctuations aslow as possible. The output voltage is controlled usingthe PWM approach. IGBT is used in four pairs andtaken as the switching device. Four pairs of diodes arealso used with the IGBTs and are placed in parallel andopposite direction. The simulation was performed at aswitching frequency of 10 kHz, and the findings werein excellent agreement with the quadrant operation'sfirst quadrant, and it was able to increase the voltageof itsinput by about five times . In addition, an inverterissuccessfully created, demonstrating the use of matrixtopology.

Abstract: This paper proposes one of the possible techniques for interacting for shape memory alloy (SMA) actuator based tactile display, which can act as demonstrator devices. This work is focused on developing a model of a pair of antagonistic high strain SMA tension actuators with independent control of force and displacement. The technology employed utilizes two Flexinol 100 micron heat actuated wires of Titanium-Nickel (NiTi) shape-memory alloy which contract when heated under pre-stress and produces up to 5% strain recovery. This phenomenon, which provides a unique mechanism for actuation, is associated with the unique interaction between the martensite and austenite crystal structures of the SMA. Physical measurements of the behaviour of the actuator elements were performed using a laser displacement sensor to verify the fidelity of response to software commands, and to measure step response to pulse-width modulated (PWM) current control at different frequencies and duty cycles. Results yielded high accuracy across a wide range of frequencies and duty cycles, proving the SMA actuation technique has potential to present and convey useful tactile information of surface deformation for virtual environment applications.

Abstract: This paper presents a mathematical model of photovoltaic with buck converter to analyze the voltage and current as a result of radiation and temperature changes as the input signal. Photovoltaic simulator models created using the C programming integrated with Matlab Simulink. The IP controller is used to control the current of a buck converter with the reference current from the dynamic model of photovoltaic. The control signal from the IP controller is used for generating a PWM signal, which is used to drive the IGBT gate of the buck converter. Input of irradiance and temperature are given to the photovoltaic simulator. Moreover, the current and voltage of the buck converter are used as a feedback to the photovoltaic simulator. This experiment is run through the system in real time and the simulation results show that changing in radiation has more significant effect on the output voltage of a solar power system compared to changing in temperature.

Abstract: A new control scheme with self-adaption is put forward in this paper. The digital control and the analog circuit are combined. A light intensity sensor can be implemented with a photoelectric triode. This sensor makes the self-adaptation control of LED possible. As a result, the light of LED can be adjusted automatically with a PWM chopper according to the ambient brightness. The whole system’s power supply is from a Boost converter which has a high efficiency. In addition, This combination improves the hommization of the system and solves the problems existing incurrent headlamps, unsafe factors are also reduced. The validity of design is verified by experimental results.

Abstract: Hydraulic actuators are widely employed for industrial automation for its high power over weight ratio, functionality in tough operating conditions and low cost. However, the dynamics of hydraulic systems are non-linear and the system subjected to non-smooth and discontinuous non-linearities due to directional change of valve opening, friction, valve overlap and changes of hydraulic pressure acted on valve spool. Taking into account the effect of nonlinear parameter variations such as bulk modulus, compressibility of oil or viscosity of oil, fuzzy logic approach is chosen. Fuzzy control can adapt the inconstant working condition and non-linear system alongside of its robustness. For PWM controlled hydraulic component such as solenoid valve, effective approximation of the flow properties in a solenoid valve is essential. In this paper, the effect of fuzzy logic approach incorporated on pulse width modulation (PWM) controlled hydraulic system is to be investigated and experimentally verified.

Abstract: In PWM controlled variable rate spraying system, spraying quantities were regulated by fast switching solenoid valves. However, hydraulic impacts were generated by these fast switching solenoid valves in pipe system, which affected stabilities of spraying quantities and atomization characteristics. In order to study pressure changing regularities when solenoid valves operated, then to design a pressure controller to improve spraying qualities in PWM controlled variable rate spraying system, Fluent was used to simulate pressure characteristics in the pipe system and pressure curves were drawn under the following 3 working conditions, solenoid valve opening, closing, and switching continuously with 5 Hz frequency and 50% duty ratio. Related experiments were carried out to test real pressure signals in the pipe based on a PWM controlled variable rate spraying system. Relative errors between simulation results and experiment results were below 10%. Thus, this simulation model of PWM controlled variable rate spraying system in Fluent was reliable to simulate pressure characteristics in the pipe in other common working conditions, and which contributed to design pressure controller and to optimize the whole PWM controlled variable rate spraying system.

Abstract: This paper deals with a Robotic arm actuated by a monomobil telescopic planetary gear and servo DC motor. Experimental model of robot was designed and manufactured at the Faculty of Engineering from Sibiu, (Patent no. 112418 CI6.B25J 18/02). The Servo DC as actuator drives a reel. Wires on the reel will produce displacement of telescopic modules from robotic arm structure. The reference as a voltage for future arm displacement is provided by a PWM generator. The rotation of the reel in one way or another has the effect of lengthening or shortening robotic arm. Robotic arm length is directly related to the PWM signal. Control of robotic arm positioning is done with a linear transducer.

Abstract: DC motor control system is an important portion of NC flame cutter height automatic adjustment device. The article made the program of DC motor control system in height automatic adjustment device, and designed the PWM DC motor control circuits. Pointed out the key problem of the system software and solved it.

Abstract: Abstract:Although high power LED is not large to replace the traditional lighting lamps and lanterns, but they are in indoor and outdoor decoration, special lighting is more and more widely used, so master the design of the high-power LED constant current drive technology, is very important to open up a new application of high power leds. LED by power and luminous brightness can be divided into high power LED, high brightness LED and common LED. In general, the power at least above 1 w high power LED, is more common with 1 w, 3 w, 5 w and 8 w and 10 w. Has large quantities of application are 1 w and 3 w LED, as w and 5 w, 8 to 10 w LED application is relatively small. Electronic and lighting industry are extremely concerned about the development and application of new technology of LED lighting. Constant current driver and improve the optical efficiency of LED is the two key problems of LED application design.

Abstract: A biped robot based its mobility imitating human movements; this development is focused on the movement of the lower limbs. The mobility of the robot is made by servomotors; because they work in a very similar way as the joints of the human’s lower limbs but with some restrictions. The logic of this system was coded on VHDL language to be implemented in a FPGA. The reason for using this hardware; is because it had fast reaction speed, its implementation is friendly and versatile also is able to handle multiple processes in parallel. This paper describes the servo characteristics and how it was used to through an FPGA make possible move a robot who imitates the human movements in the sagittal plane, also show the mechanical design. Shows that the FPGA is better suited in this case than a micro controller to follow multiple paths at the same time.