International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 09 Issue: 05 | May 2022
p-ISSN: 2395-0072
www.irjet.net
Finite Elements Analysis and Optimisation of Robotic Arm Under Dynamic Loads Sandeep Chowdhry1 1Engineering
Consultant & Trainer, Chandigarh, India ---------------------------------------------------------------------***--------------------------------------------------------------------evaluate the optimised design for high structural vibration Abstract – To design a high-performance Robotic Arm, it is
frequencies. This study intends to contribute to the literature on structural design optimisation under dynamic loading.
essential to analyse it under dynamic loads. This study aims to explore the structural strength of the Robotic Arm under dynamic load, optimise the weight and evaluate the optimised design. Dynamic simulation of Robotic Arm is performed using Auto Desk Professional (AIP). In addition, Finite Element Analysis (FEA) is performed on the Robotic Arm under dynamic loads. Response Surface Method (RSM) is used for optimisation. The data is analysed using graphs, descriptive statistics and inferential statistics. The results show that the maximum resultant moment on revolute joint 1 is more than five times that on revolute joint 2. The optimisation led to 50.17% and 32.93% reduction in the safety of factor link 1 and link 2, respectively. The thickness of link 1 has a more considerable effect on the safety factor and mass than its cross-section area The overall mass of the Robotic Arm is reduced by 36.69%. The optimised Robotic Arm’s first natural frequency is more than three times the maximum design frequency. The maximum stress produced in the Robotic Arm is well below the yield strength of the Aluminium-6061. It is concluded that the high structural stability of the base and link 1 are essential to improve the performance of the Robotic Arm. Boundary conditions may be selected according to the actual working environment to get more accurate FEA results. There is a possibility of using materials with yield strength lower than Aluminium-6061.
2. DYNAMIC SIMULATION Autodesk Inventor Professional (AIP) 2016 is used to create the Robotic Arm assembly, as shown in Fig. 1. The detailed mechanism of connection of motors to link 1 and link 2 is not shown. Aluminium-6061 is assigned to the Robotic Arm. The base is fixed. In a dynamic simulation environment, revolute joint 1 is created between the base and link 1. A revolute joint is created between link 1 and link 2. Revolute joint 3 is created between link 2 and gripper. Gravity load is apllied in the vertically downward direction. Electric motors are suppresed in the dynamic analysis as they are mounted on the base.
Link 2
Link 1
Gripper
Key Words: Dynamic Simulation, FEA, RSM, Modal Analysis 1. INTRODUCTION This study continues the research to design a Robotic Arm for tracking and force control for education [1]. It is essential to perform the structural design analysis under the dynamic loads as it considers the effect of joint positions, velocities, accelerations and reaction forces. These reaction forces help test the components similar to the actual working environment. The weight is a prime optimisation parameter, and structural optimisation can be categorised as sizing, shape, and topology optimisation [2]. The finite Element Method (FEM) in modal analysis results show that an increase in preload force leads to a decrease in natural frequencies at a low level [3]. These findings are in agreement with the experimental results [4]. Therefore, the main aim of this study is 1) To analyse the structural strength of the Robotic Arm under dynamic loading; 2) To perform structural optimisation to reduce weight; 3) To
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Electric Motor
Fig - 1: Robotic Arm
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