Sharif Digital Repository

During the past decade, Electro-Hydraulic system has performed a significant role in industrial engineering as an actuator for high performance and precision positioning applications. In this case, many control methods have been developed for an electro-hydraulic actuated clutch. In this paper a Linear Quadratic Regulators (LQR) is proposed to trajectory control of a wet clutch actuated by a hydraulic servo valve mechanism. Simulation study was performed using linearized mathematical model of the system implemented in MATLAB software. Based on the simulation results performance of the proposed controller was evaluated and discussed  

Ultra-high precision machining is proposed by externally actuating the work piece in linear motions in the X-Y plane and linear motion in the Z-axis. To solve the problems in the machining process such as nonlinearity and low repeatability positioning accuracy of machining tools in a larger scale, a novel platform for cutting tools in micro machining based on electrostatic linear micromotors and piezoelectric stack actuator system is presented. © 2017 IEEE  

Burr in drilling plays an important role on product quality, so analysis the burr height is essential at the final production. This paper presents the application of Taguchi method for survey the burr height by adding ultrasonic vibration to the process. In this paper L18 orthogonal array based on Taguchi techniques was used in the design of experiments. Analysis of Variance (ANOVA) was used to determination the effect of drilling parameter on burr formation. Influence of spindle speed, feed rate and percentage of SiC particle was investigated in with and without ultrasonic assisted drilling. In this paper drilling of Al/SiCp MMCs with 5, 15 and 20 wt% of particulate SiC in dry drilling... 

Chatter suppression in machining processes results in more material removal rate, high precision and surface quality. In this paper, a single degree of freedom model of orthogonal turning process is used to set up the delay differential equation of motion with considering the tool wear effect as a contact force between the workpiece and tool flank surfaces. Sinusoidal spindle speed variations with different frequencies around the mean speed are modulated to disturb the regenerative mechanism. The optimal amplitudes of the speed modulations are found based on a genetic algorithm such that the input energy to the turning process is minimized. Results of the stability analysis and the... 

A traveling mass due to its mass inertia has significant effects on the dynamic response of the structures. According to recent developments in structural materials and constructional technologies, the structures are likely to be affected by sudden changes of masses and substructure elements, in which the inertia effect of a moving mass is not negligible. The transverse inertia effects have been a topic of interest in bridge dynamics, design of railway tracks, guide way systems and other engineering applications such as modern high-speed precision machinery process. In this study an analytical-numerical method is presented which can be used to determine the dynamic response of beams carrying...