فهرست مطالب

Journal of Majlesi Journal of Mechatronic Systems
Volume:6 Issue: 1, Mar 2017

  • تاریخ انتشار: 1396/01/14
  • تعداد عناوین: 6
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  • Omid Sharifi-Tehrani, Alireza Sadeghi, Seyyed Mohammad Javad Razavi Page 1
    In aerial applications, for identifying friend and foe, Traffic control and air defense, a system called IFF (identification friend or foe) for military vehicles or ATC (air traffic control) for civilian vehicles is used. For unmanned aerial vehicles (UAVs), because of widely use, it is inevitable to use IFF/ATC systems for both air defense against enemy and traffic control. In this paper, an efficient antenna in terms of size and parameters (gain, VSWR, radiation pattern and impedance), is designed and simulated. Obtained results showed good performance comparing with civilian and military airplane antennas.
    Keywords: Antenna, IFF, ATC, UAV
  • Omid Sharifi-Tehrani, Saeed Talati Page 5
    The periodic partial updates (PPU) method is evaluated. Cost, performance, portability and physical size considerations compel serious resource limitations on adaptive signal processing systems. Partial-Selective weight updates techniques can be used to decrease the resource usage and hardware complication in practical fields at the likely price of greater steady-state MSE error and more lower convergence speed. Periodic partial update (PPU) is one of partial-selective weight update techniques by which, on behalf of updating the all weights (coefficients), a limit number of the weights are updated at each epoch. The performance, convergence speed and MSE error of periodic partial updates is evaluated in the presence of white and colored Gaussian input. It is concluded that in some practical fields, this method could be considered on behalf of full-update algorithm with some loses on quality.
    Keywords: Adaptive signal processing, Convergence speed, Partial-selective weight update, Resource usage
  • Mohsen Azizi Page 11
    An UPFC may be applied for steady-state power-flow and voltage control as well as for mastering dynamic phenomena like transient-stability margin enhancement, oscillation damping, etc. For these tasks the Lyapunov energy-function approach is frequently used as a convenient way to control or analyze the electric-power system (EPS). The basis for the implementation of such an approach is to know the energy function of the EPS. Currently, this is not possible for the EPSs that include UPFCs, because the already known energy functions that proved to be suitable for an EPS do not include such a device. In the present paper, the convenient operation and control of UPFC for transient stability improvement are considered. Considering that the system’s Lyapunov energy function is a relevant tool to study the stability affair. UPFC energy function optimization has been used in order to access the maximum of transient stability margin. In order to control UPFC, a fuzzy-sliding mod (FSM) and PI controller have been used. The designing results have been studied by the simulation of a single-machine system with infinite bus (SMIB) and another standard 9-buses system (Anderson and Fouad, 1977).
    Keywords: Transient Stability, Emotional learning, Unified Power Flow Controller (UPFC)
  • Mojtaba Shahab, Majid Hajihosseiali, Nasser Fatouraee Page 21
    Many spinal problems which could lead to pain are associated with the instability of spine. Experiments have shown that the ligamentous spine is inherently unstable, because the isolated lumbar spine buckles under approximately 90N load. Spinal deformities can originate instability of spine, but studies have shown that in normal state, combination of the various mechanisms, such as muscle forces and intra-abdominal pressure render the spine stable. In this research, we try to find out the relationship between spinal deformity and lumbar muscles activity.
    According to the biomechanical and geometrical complexity of the spine, it’s crucial to use biomechanical models in order to study the stability of the spine. Granata and Wilson presented a simple two-links model of lumbar spine considering twelve muscles, and by satisfying the mechanical stability conditions, they calculated the muscular forces for different physical activities. Through experiments conducted using Electromyography (EMG), activity of the trunk muscles were recorded and compared with the predicted model results.
    In this paper, Granata analytical model is verified using a finite element model. Muscular forces are calculated subject to satisfying the spinal stability conditions for a standing Granata analytical model, and they are compared with the numerical results. Subsequently, a similar model is adapted to the subjects with scoliosis, and spinal stability conditions in these models are compared with healthy one. Then the relationship between progression of spinal deformities and lumbar muscles activities is illustrated. Finally contribution of spinal deformities on the stability of spine is studied. In the more complex physical activities such as load lifting and bending, it is inconvenient to use analytical methods, contrarily the finite element method is a more appropriate tool to study the stability of the spine.
    Keywords: Biomechanical modeling, Spinal deformities, Muscular Forces, Granata model, Low-back pain, Idiopathic scoliosis, Stability
  • Saeed Balochian Page 33
    Pantograph is a device that collects electrical current from overhead line to power an electrical locomotive. Pantograph must transmit electrical energy to high-speed rail system without arcing and interrupting power. This paper presents a Fractional Order Fuzzy PID (FOFPID) technique for tuning the optimal control gains of FOPID controller. The Fractional Order Fuzzy PID controller (FOFPID) can decrease rapidly the contact force variation between the pantograph and the catenary in order to minimize damage and wear of the contacting elements. The results are verified that system responses with proposed controller have better performance parameters in both transient state and steady state.
    Keywords: catenary, pantograph, rail transportation control systems, railway, controller, adaptive fuzzy fractional order controller
  • Abbas Rasaienia Page 43
    Ball and beam system is a nonlinear and unstable system which is used as an applied sample in research laboratories as a tool to represent the performance of different control algorithms. The present study utilizes hardware in the loop realization of classic (PID type) and fuzzy controllers by Sugeno fuzzy inference approach in order to evaluate their performances. All activities for design and simulation of controller were performed by MATLAB and Simulink software. Then, the simulation environment of MATLAB was linked to the operator interface as well as actuators and sensors in hardware in the loop structure by writing a real time kernel through DAQ interface cards. Simulation results show the appropriate performance of fuzzy controller in comparison to PD and PID controllers. By using fast processors for implementation of fuzzy controller, settling time, overshoot percentage and steady state error of the closed loop system were significantly improved in comparison to the common classic structure. Also, all simulation results were verified by hardware in the loop test.
    Keywords: ball, beam, fuzzy control, hardware in the loop, HIL, classic control