Sharif Digital Repository

In this paper, a radial basis function neural network-based (RBFNN) adaptive inverse controller for real-time position tracking control of a two phase hybrid stepper motor in microstep mode is presented and compared with a conventional fixed gain stand-alone PID controller. Also it is compared to the same neuro-controller using feed forward backpropagation neural networks (FFBP) presented by the same author showing superior performance of RBFNN to FFBP neural networks. A radial basis neural network is used as a controller in the adaptive inverse control method combining with a closed loop PID controller to ensure system's initial robustness and closed loop stability and improves the... 

This paper presents the prototype design and fabrication of a magnetically actuated miniature pump that utilizes self-sealing capability of ferrofluid-covered permanent magnets in both pumping and valving mechanisms. The valving action is performed by employing one active valve along with two nozzle/diffuser elements. Two cylindrical permanent magnets are placed inside the flat-wall channels: One magnet acts as the active valve and the other one serves as a reciprocating piston actuating the working fluid. In order to seal the gaps between the channel walls and the permanent magnet of the valve/piston, ferrofluid is used to cover the surfaces of both magnets. The valve and the piston are...