Print ISSN: 1813-0526

Online ISSN: 2220-1270

Main Subjects : Mechatronics Engineering

Simulation and Experimental Gait Cycle of Two Types of Degree of Freedom Bipedal Robot

Ali Fawzi AbulKareem; Ahmed AbdulHussein Ali

Al-Rafidain Engineering Journal (AREJ), 2020, Volume 25, Issue 2, Pages 176-188
DOI: 10.33899/rengj.2020.127579.1046

Another type of legged robots is a bipedal walking robot or humanoid robot, which can be designed to implement various functions as necessary and mimic like a human. Often, balance while moving and when the first leg in the swing process and the second leg on the ground is difficult than most other kinds of robots. Two bipedal robot prototypes are designed with 10 degrees of freedom and 17 degrees of freedom to fulfill a gait cycle. The robot's locomotion can also be controlled via two types of microcontrollers, Arduino microcontroller and LOBOT LSC-32 driver. So, the KHR-2HV simulation model by Webots is used to simulate the experimental results of the bipedal robots. The results showed that the cubic polynomial foot trajectory for 10 degrees of freedom and 17 degrees of freedom bipedal robots are (  with regression 0.9276) and (  with regression 0.939) respectively.After several methods for programming, the bipedal robot by LOBOT LSC-32 driver model is the better than Arduino with PCA 96685 driver-16 channel servo driver.Experimental results carried out during the KHR-2HV simulation model by Webots program. This model gives a better estimation and a fast response to confirm the stability of the10 degrees of freedom and 17 degrees of freedom bipedal robots.

Modal Analysis of Quill Shaft in Turbo-generator Unit Based on SolidWorks

Dr. Fares. Q. Yahya

Al-Rafidain Engineering Journal (AREJ), 2019, Volume 24, Issue 1, Pages 55-66
DOI: 10.33899/rengj.2019.163197

The main goal of this work is to carry out a numerical modal analysis of a Quill shaft of turbo-generator unitaffiliate to Mosul gas turbine station, using a trail version of popular finite element analysis software SolidWorks. The main function of Quill shaft is to protect the turbo-generator unit against overloads due to electrical network faults. The high flexibility of this shaft makes it capable of absorbing high displacements of resonance phenomena. This analysis is essentially needed to study the effect of transient loads applied to Quill shaft of turbo-generator unit under severe loading conditions such as electric network disturbances. The first five values of critical  frequencies and mode shapes of axial, bending, and torsional vibrations were studied and analyzed. Each mode has been isolated separately by applying a special type of boundary conditions (restraints) available in program. The three types of natural frequencies have been found and reported. It was observed that the fundamental values of each three types of natural frequencies are relatively high and out of the range of Quill shaft operating speed. Finally, it has been concluded from all analyses that Quill shaft under consideration is safe from the stand point of modal analysis. The results show that the Quill shaft is not running at any of each three types critical speeds. Therefore, the resonance phenomenon for all three types of vibrations can not be happened no matter how high the amount of transient load applied.