Applied Mechanics and Materials Vols. 110-116

Abstract: the optimum selection of grippers is a complex task as it involves large tangible and intangible attributes and also availability of large options in the market. In this present work, an endeavour has been made to quantify intangible attributes by using fuzzy MADM approach and then overall numerical index has been find out by using Graph Theoretic Approach (GTA) So, that the customer can visually compare different models.

Abstract: Engine rotational dynamics can be estimated from the tooth signals of the crankshaft wheel. The accuracy of the calculation rises when the number of tooth increases. However, the engine control unit (ECU) needs to detect the tooth position and converts it into time information. It will overload the interrupt system. In order to overcome this problem, the field programmable gate array (FPGA) is proposed to implement the engine rotational dynamics calculation with stroke identification algorithm. The FPGA can accelerate the interpolation and the multiplication processes by implementing them in parallel computation. Thus, the proposed method can calculate the engine rotational dynamics in real time, and then the calculation results can be transferred into the robust Kalman filter which was established by Matlab/Simulink in a computer, i.e., a simulated ECU. Finally, a 125cc scooter is utilized to verify the proposed algorithm. The test results show that the proposed method can be used to obtain precise information of engine rotational dynamics.

Abstract: Studies on differential ejector configuration have been carried out with a view to obtain the optimal entrainment of low pressure gas flow by injecting the motive gas at an appropriate pressure and angle of injection. The length of mixing has been kept constant in one case and varied in another to get results for optimal angle of ejection (between 0 to 90 degrees) for varying mass flow rates between 0.02kg/s and 0.08kg/s, stagnation pressures between 200kPa to 2500kPa and conduit diameter being 50mm. The predictions made are validated employing a versatile code Fluent in 2-d, viscous, turbulent flow formulation. Since the flow is supersonic, compressible form of SIMPLE algorithm is used along with a first order upwinding scheme for correctly predicting the properties inside the flow domain. Various curves have been plotted depicting variation of Mach number with angle of ejection and Mach number with mass flow rate for various pressures and angles of ejection.

Abstract: A full order model of an aeroelastic aircraft has too many parameters to yield satisfactory estimates. In this paper, using simulated data, rigid body and aeroelastic derivatives are estimated in longitudinal axis for single elastic mode. The proposed approach uses an integrated model structure. It emphasizes the use of estimation techniques that have the capability to accurately determine modal characteristics in those flight test situations where the measured data is dominated by elastic effects. Output error method in time domain is applied to the simulated flight data to identify the aircraft derivatives.

Abstract: An optimal damage detection sensor placement methodology is presented. The techniques utilize a Particle Swarm Optimization (PSO) algorithm. The proposed method is iterative in nature and it permits the use of incomplete measurements. Also, it allows diversity of damage detection algorithms to be used to generate the PSO required fitness function. However, in this work Linear Matrix Inequalities are used as the damage detection schemes. Computer simulations of a cantilevered beam will be used to demonstrate the effectiveness of the methodology.

Abstract: This paper is devoted to design a control system for robot manipulator to optimize motor torque due to external impulsive loading exerted on the manipulator. Under impulsive loading, overloading may occur in the absence of any monitoring on the torque. To avoid the overloading, impedance control is proposed as a force control strategy. Here impedance control based on force feedback of which has hit the end-effector modifies the reference trajectory. In fact, instead of resisting against impulsive loading up to extreme power of the motor, the proposed design generates small movements in the direction of impact. Therefore, the motor produces less torque in comparison to the absence of impedance control. A supervisory system assisting fuzzy logic has been used to adapt impedance controller parameters with various impact conditions. The simulation result confirms the improvement of the manipulator behavior which yields sensible reduction in motor developed torque in comparison to single PID controller.

Abstract: This paper presents the design and implementation of a system for detecting the microscopic faults and defects present in the electrical machinery using the vibration analysis. Vibration analysis based on mechanical bearing frequencies in industrial machines is currently used to detect the presence of a fault condition. Since these mechanical vibrations are associated with variations in the physical disturbances of the machine, the air gap flux density is modulated and peak amplitudes are generated at predictable frequencies related to the electrical supply and vibration frequencies. Spartan3E FPGA was used in this process to reduce the time of detection and to increase the accuracy in displaying the fault position. Induction motor HS-1 by High Speed Motors is taken as the device under test to perform the vibration analysis and draw the results. The device SI-100 by Syscon Instruments is the sensor used to extract the analog information of interest from the motor during the implementation. In addition all this phenomena is also tested using LabVIEW2009 and NI-ELVIS to check the accuracy of the results.

Abstract: This work examines the development and implementation of an integrated sensor platform based on graphical monitoring and control. This work focuses mainly on determining the state of different switch sensors and to display the sensor state results on the platform using graphical monitoring and control technology. This platform integrates graphical monitoring and control technology with four different switch sensor devices. Via this platform, students can determine the characteristics, function, and application of different switch sensors and learn to use graphical monitoring and control technology. Students then learn, verify, and realize lecture concepts by performing different sensor experiments in the laboratory via this novel platform.

Abstract: In this paper, semi active control of non-ideal mechanical system with Magneto-Rheological (MR) damper is presented. The setup composed of a motor operating on a structure with mass M connected to a fixed frame by a non-linear spring and with a linear viscous damper. From the investigations carried out it is possible to observe the DC motor influence on the vibrating system along with non-periodic motions with chaotic characteristic. To control this system linear viscose damper is substituted by MR damper. A semi-active control method, sky-hook control is used in this study. Our results suggest that the addition of a MR damper turns the phase space smoother and it is so effective to suppress chaos.

Abstract: Low temperature radio frequency plasma is widely used in low temperature plasma processing medium for material processing in many fields including microelectronics, aerospace, and the biology. For proper utilization of the process, it is very much important to know the plasma parameters. In this paper a novel technique is used to determine the plasma parameters from the electrical discharge characteristic and the power balance method. The homogeneous discharge model is used to evaluate the relation between the plasma parameters with the discharge characteristics. The electron density and temperature is found to be well agree with the Langmuir probe data in the range of 0.5x1016 to 45x1016 cm-3 and 1.4 to 1.6 ev for wide range of rf power.