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Evaluation of the strength of a three axis serial robot performing a task by integrated dynamic analysis
Three axis serial robots with different sizes are widely used for pick and place, welding and various operations in industry. Developments in mechatronics, which is the synergistic integration of mechanism, electronics and computer control to achieve a functional system, offer effective solutions for the design of such robots. The mechatronic design process involves solid modeling, assembly, rigid body dynamics, finite element rigidity analysis, motion control and computer programming. The integrated dynamic analysis of robots is usually used in design stage. In this study, it is offered that it can also be used in the application stage.In this study SolidWorks, CosmosMotion, ABAQUS is used with an integrated approach. The integration software is developed in VisualBasic by using the application programming interface (API) capabilities of these programs. ABB-IRB1400 industrial robot is considered for the study. Different trajectories are considered. Each task is evaluated by kinematic analysis first. If the task is out of the workspace then the task is canceled. This evaluation can be done also by robot programs like RobotStudio. It is offered in this study that the task must be evaluated by considering the limits for velocities, motor actuation torques, reaction forces, natural frequencies, displacements and stresses due to the flexibility. The results are shown on kinematic, kinetic and rigidity evaluation charts. The results of this work can be used for optimal usage of robots.
Trajectory planning of a six axis serial robot based on dynamic analysis
Serial robots are by far the most common robots used in industrial applications such as welding, pick and place, and various processes. Computers and engineering programs play important role to constitute motion analysis and design process. These days, engineers can analyze all parameters to produce the generous robots which are required for the process and find effective solutions quickly by using computer programs with the development of the technology.In this study, a six axis serial robot is produced by using integrated approaches with parallel analysis in SolidWorks, CosmosMotion,VisualBasic, Abaqus and Adlink Motion Control Card. The parts of the robot are modeled in SolidWorks, rigidity is verified with finite element analysis in Abaqus and produced the real model of the robot. Kinematic analysis is studied in CosmosMotion by defining the velocity profile to the end effector point through the software algorithm developed in VisualBasic, which uses the application programming interface (API) capabilities. Different tasks are given to the robot in this study. The kinematic workspace and maximum motor velocities are evaluated by inverse kinematic analysis for each task. The kinetic workspace and maximum motor torques are evaluated by forward kinetic analysis. The rigidity workspace is evaluated by finite element analysis. The optimum trajectory is chosen after reviewing dynamic analysis and finite element results and the same trajectory is generated using ADLINK motion control card. Velocity mode is used. The maximum deviation for each motor is determined which is between the sending velocity profile data and the receiving feedback velocity profile data and compared whether the deviation values are in acceptable ranges.
Alüminyum döküm tezgahlari için metal besleme robotu tasarimi ve analizi
Today, robots are used at many industrial fields due to their flexibility, efficieny and accuracy. It is possible for man to increase quality of life by using robots for dangerous, dirty and hard labor jobs instead of human. For some production processes, it is not possible to be done by human because of its extreme enviroment conditions or sometimes accuracy of human is not enough. If introduced correctly, industrial robots can improve the job quality and cost savings thanks to their operation efficiency.It is great importance that right material is chosen and that work is determined correctly for industrial robots to be effective. Therefore for reliability of this kind of applications, it is of great importance that engineers involved follow up all design steps and analyse well obtained data. Basicaly, robots consist of two main units which are the mechanical and the control system. In this study, design of mechanical units of robot application will be discussed.In this study, principles to be considered for robot application were determined. A material feeding robot in order to be used at an aluminum die casting system is designed and analyzed. At the design process, environment and work conditions were considered and according to these data, appropriate modules were selected. Static and frequency analysis were handled through the use of Ansys and Solidworks. Results obtained from analyses were evaluated and design was updated.
Modelling and application of a bipedal mechanism
Bipedal walking is considered as one of the most important movements of human-being with full of synchronized relative motions of limbs, joints and muscles of both right and left legs with respect to each other, in changing walking velocities. Bipedal walking system is not only composed of dynamic mechanisms but it is also considered as a combination of these mechanisms with various control, sensory and actuator systems. In this work, basic definitions about bipedal walking are given and based on these definitions, mathematical model of a bipedal walker in sagittal plane is derived. After the solutions for the system dynamics are obtained, model based control of the ankle and hip joint trajectories are achieved by using feed forward compensation methodology and simulation results are carried out. Bipedal walking researches are not limited only with the two-legged walking robots and models. Walking aid devices are also related with these studies. For this reason a walking aid device which is an artificial hybrid leg having a polycentric knee joint is designed in this study. Polycentric knee joint considered here is a four bar mechanism. Theoretical background of the artificial leg model, including kinematic and dynamic analyses of the leg is explained and then an experimental setup is built. Two different trajectory control structures which are the point to point position control and the feed-forward compensation with disturbance rejection strategy are developed and experienced on the experimental setup. Results which show the performance of the control strategies are given at the end of the study
Dynamic analysis of non lubricated, multistage piston air compressors
The primary purpose of this study is no explore is to explore the design and basic calculations of the Non Lubricated, Multistage Piston Air Compressor. These type of compressors are special machines in the industry because of the working conditions. These machines are used where pure air is required, such as PET blowing industry, Food and Medical Sectors, Electronic industry etc.
Detection of rolling element bearing faults via vibration analysis
Rolling element bearings are the main components in rotary machines due to their advantageous friction characteristics. It is very important to keep the rolling element bearings in good condition in terms of general machine health. In this study, the condition of deep groove rolling element bearings is monitored by means of vibration measurement. Experimental vibration signals are collected from a test rig, including two rolling element bearings, which carry a shaft having an unbalanced mass on it. A local defect on the inner or outer race of one of the rolling element bearings is introduced artificially and vibration measurements are performed using a portable vibration analyzer in terms of displacement, velocity and acceleration. Some statistical indices such as rms, peak to peak and kurtosis values of the vibration signals are calculated for healthy and faulty cases, in order to obtain the change in the time domain parameters due to bearing deterioration. The vibration measurements are performed for a broad range of shaft speed. Signs of the bearing deterioration are also investigated in frequency domain by the Fast Fourier Transform (FFT) and Short Time Fourier Transform (STFT). As the main part of this study, a nonlinear time domain transform, named as Curve Length Transform (CLT) is applied to the vibration signals for diagnostic purposes. The statistical indices of the CLT signals for healthy and faulty cases are calculated and compared, to make a decision about the condition of the rolling element bearing. The statistical indices of the CLT signals are also compared with the statistical indices calculated for raw vibration signals, in order to show the efficiency of the Curve Length Transform. The experimental results show that the CLT can be used successfully to enrich some time domain parameters, which give useful information in capturing the local bearing failures.
High frequency vibrations of thin plates
In the analysis of high frequency dynamics of vibrating systems, an averaged prediction of energy is generally of interest to describe the response level. However, energetic response parameters do not include modal information and thus exhibit smooth characteristics. Therefore, it is obvious for systems subjected to high frequency excitations that an efficient tool is required. This doctorate study mainly deals with the development of such an approach.In this regard, a novel scheme for the discrete high frequency response analysis was introduced in the presented thesis. The scheme is based on Discrete Singular Convolution (DSC) and Mode Superposition (MS) methods. The accuracy of the DSC-MS is validated for thin beams and plates by comparing with available analytical solutions. The performance of the DSC-MS was evaluated by predicting spatial distribution and discrete frequency spectra of the vibration response of thin plates with two different boundary conditions.As a secondary study, this thesis introduced two different application procedures for classical DSC method. The first one is an algorithm for free vibration analysis of symmetrically laminated composite plates. The second one is an implementation for free vibrations of thick beams and plates. Comprehensive comparisons with open literature state that both procedures presented for the DSC are rather effective and accurate.
Design and control of a lowerknee prosthesis
In this thesis, transfemoral amputations and prosthetic knees evolved for transfemoral amputations are investigated and the electronic control unit of prosthetic knees is designed. The first stages of this work contain information about human walking in medical meaning and bipedal walking. Then, definition of transfemoral amputations, leg biomechanics when walking and phases of walking is discussed. After that, prosthetic knee design for transfemoral amputations is mentioned and prosthetic knees developed by worldwide companies are investigated and discussed in details. At the last stage, electronic control unit is designed and produced for prosthesis used by above knee amputees.
In- plane dynamic stability analysis of laminated curved beams
In this study, the effects of variations of subtended angle, orientation angle and curvature of a laminated composite arc, having an in-plane curvature, on the natural frequencies, static and dynamic stability have been investigated by using the Finite Element Method. Sabir and Ashwell?s displacement functions have been used to develop a finite element model to employ in this study. In-plane vibration and in-plane buckling analyses are also studied. In addition, the results obtained from this study are compared with the results obtained from Ansys for the fundamental natural frequency and critical buckling load. The effects of variations of subtended angle, orientation angle and curvature of curved beam and static and dynamic load parameters on the stability regions are shown in graphics. Moreover, analysis of natural frequencies, buckling and dynamic stability for curved composite beams are also compared.
Analysis of structural acoustic coupling of plates
In vibration and noise control engineering, vibration of a thin plate backed by a cavity, the sound in this cavity and mutual effects of vibration and sound are of considerable importance in the accurate and realistic design of various machines and vehicles. Due to the mechanical, acoustical or both type of excitation on the thin plate-cavity system, a coupling phenomenon occurs between vibration and sound. This thesis mainly focused on a parametric study based on a vibro-acoustic model including a plate-cavity system in order to examine the coupling effects. All analyses were performed by using I-DEAS Vibro-Acoustic module that uses coupled FEM/BEM approach. The parametric free vibration study includes six cases composed of different cavity depths and plate thicknesses. Forced frequency response analysis covers five different excitations, including harmonic, almost periodic, random structural and acoustical excitations. In this regard, free and forced uncoupled and coupled analyses were evaluated by structural, acoustical and energy point of views.
Vehicle guidance by using GPS aided Kalman filter
In this thesis, a novel approach that integrates global positioning systems (GPS) and Kalman filtering is presented. In order for a mobile robot to localize and navigate itself, a novel measurement process is developed which makes use of two low-cost GPS units. Using these ordinary, low-cost GPS receivers, a completely differential GPS-like system is achieved algorithmically in the absence of real DGPS service. One of these units is placed on an accurately surveyed geographical point and it is taken as a reference station for the other mobile unit. They are presumed to see the same satellites, hence the adoption of same measurement noise characteristics is considered to be appropriate. After the measurements are differentially corrected, a discrete Kalman filter algorithm is adopted to estimate optimally the position of a robot vehicle in order to navigate itself autonomously. The noise sequences of the Kalman filter are accepted as zero mean white Gaussian, and different filter performances are obtained by adjusting the parameters of the filter. In addition, trajectory estimation of the vehicle is realized using Kalman filter technique. Therefore, mapping of a specific geographical field in latitude and longitude is obtained. The results of the experimental testing of the DGPS algorithm and Kalman filtering show the effectiveness of the proposed approach.
Controlling a non-holonomic vehicle via artificial neural networks
The use of learning autonomous robots is inevitable in modern production technologies. Modern industries require efficient production, précised measuring and robust control systems due to the hard competition of perfect product manufacturing whereas human wants more comfort in life. Various kinds of robot vehicles for various tasks have been developing increasingly not only in production industry but also in daily life. In this research, a vehicle model with four wheels is built and equipped with actuators, different types of sensors, communication devices, data acquisition and control units in Automatic Control Laboratory of Mechanical Engineering Department of Dokuz Eylul University. On this developed autonomous wheeled mobile robot model, Dempster-Shafer evidence theory is tested at first step in means of sensor fusion for having more reliable data from sensors. Fuzzy logic and most types of artificial neural networks architectures which are popular on autonomous mobile robots are explained starting with basic equations and control parameters, revealing the advantages of ANNs use on autonomous mobile robots in second chapter of this thesis. Chapter three covers the kinematic analysis of mobile robot model. It is the fourth chapter, in which the experimental data and results are demonstrated. The conclusion part, which is named as chapter five, is the part in which the results are evaluated in not only in means of technical or scientific research but also in means of daily life use
70 kg uç nokta yük kapasiteli pres yükleme robotunun mekatronik tasarımı
MECHATRONIC DESIGN OF 70 KG END POINT LOAD CAPACITY PRESS FEEDING ROBOT ABSTRACT In this study, a cartesian robotic system was designed to save manpower and increase efficiency and ergonomics, instead of manually loading to the rounding press, which require repetitive stacking the disc raw material products weighing 70 kg, in my working company. The system consists of three parts: two-axis motion-controlled robot arms, a special purpose gripper and a product centering platform. Within the scope of the study, mechanical and control system designs were completed. In the design phase, an experiment was designed by using the Minitab statistical data analysis program for determining the effective factors. Autodesk Inventor, Nastran CAD programs and engineering tools were used for computer aided design in the mechanical design process. In addition, the static analyzes were tested by making production trials in the company workshop. The designed system can also be adapted as an unloading system. As a result, there will be a decrease in labor costs and the number of work accidents, and an increase in production numbers. When the costs of the loading and unloading system and the earnings returns of the factors are calculated, the investment can be amortized within 1 year. Annual potential earnings return will be an average of 250.000 USD. The aim of the study, transforming theory and engineering knowledge into practice, finding solutions for some problems in my working company and contributing scientific studies. Keywords: Cartesian robots, mechanical modeling, cost gains