Journal of the Association of Engineers, India

N. Prabhu ¹, M. Dev Anand ²

Affiliations
1 Department of Mechanical Engineering, PSN College of Engineering and Technology, Tirunelveli-627 152, IN
2 Department of Mechanical Engineering, Noorul Islam Centre for Higher Education, Kumaracoil-629 180, Kanyakunari District, IN

Abstract

This paper concerns with the dynamic analysis of a SCORBOT-ER Vu plus robot arm, used for doing successful robotic manipulation task in its 3D workspace. The SCORBOT-ER Vu plus robot is a five DOF of vertical articulated robot and all the joints are revolute. The forces and/ or torques required to cause motion of a system of bodies was studied using dynamic analysis, which is very complicated one for robot manipulator. Usually, the end-effector is to be guided through a given path with suggested motion characteristics. The actuated joints are applied with a set of torque and /or force function, to produce that motion. This actuating torque and/or force functions depends on several parameters includes spatial attributes of given path, mass properties of links, payload, externally applied forces and so on. There are two different points of view namely dynamical analysis and dynamical synthesis to tackle the dynamics of robot manipulator. Dynamic analysis handles with the derivation of equations of motion of a given manipulator that involves two problems namely direct dynamics and inverse dynamics. Among the two, direct dynamics can be defined as a set of actuated joint torque and/or force functions, calculates the resulting motion of the end-effector as a function of time. While inverse dynamics is defined as a trajectory of the end-effector as a function of time, that finds the set of actuated joint torque and/or force functions producing that motion. The computational efficiency of direct dynamics is not taken into account, as it used primarily for computer simulations of a robot manipulator. While efficient inverse dynamic model is considered as important for real-time, model based control of a robot manipulator. The Lagrangian equations of motion and the principle of virtual work are utilized to carry out the dynamical analysis of robot manipulators. The mathematical model of dynamic parameter sets are solved using MATLAB 7.10 and dynamic solutions obtained is found to be identical with the real time readings of robot arm.

Keywords

Forward Dynamics, Inverse Dynamics, Robot Manipulator, Lagrangian Equation.

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R. Rajesh ¹, M. Dev Anand ¹

Affiliations
1 Department of Mechanical Engineering, Noorul Islam Centre for Higher Education, Kumaracoil–629180, Kanyakumari District, Tamilnadu, IN

Abstract

Advanced trade materials such as polymers, ceramics, composites, and super alloys play an ever increasing important role in modern manufacturing industries. There are many applications, where engineers have reached the performance limit of metals, and there is no alternative but to seek the use of advanced material in various applications like aluminum alloy and composite. Machining of aluminum alloy and composite requires the need for better understanding of cutting processes regarding Material Removal Rate (MRR) and Surface Roughness (Ra). To meet the challenges of the changing world, the Electrical Discharge Machining (EDM) process must have the process capability, accuracy and robustness. In EDM process, it is important to select machining parameters for achieving optimal machining performance in these types of materials. To achieve this goal, the EDM process has to be modeled and optimized. In this work, Response Surface Methodology is used to investigate the effect of six controllable input variables namely peak current, discharge voltage, pulse on time, pulse off time, spark gap and oil pressure and also two output variables like MRR and SR are the responses. The experimental work is to know the effect of above-mentioned six input variables on EDM and to conclude this effect on the MRR and SR. This paper describes optimizations of EDM processes using RSM giving the details of formulation of optimization models, solution methodology used and optimization result in machining of Al alloy with HE9 and LM25 Al/10% SiC.

Keywords

Electrical Discharge Machining, Response Surface Methodology, Surface Roughness, Material Removal Rate, Process Parameters.

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