scholarly journals Sensitivity analysis and optimal design of conventional and magnnetorheological fluid brakes

2018 ◽  
Author(s):  
◽  
Salwan Obaid Waheed Khafaji
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Electric Current ◽  
Design Parameters ◽  
Mr Fluid ◽  
Magnetic Current ◽  
Wide Range ◽  
Sinusoidal Input ◽  
Angular Velocities ◽  
Do So

Mechanical and electrical brakes have dominated the braking industry for many years and will most likely continue to do so for the foreseeable future due to their low cost and adequate operating performance, wide range of applications, vehicle engineering, civil engineering, and biomedical engineering. Simple mechanical drum brake and magnetorheological (MR) fluid brake have presented in the current work. The main objective of this work is to increase braking torque, and to develop a new optimal design of MR fluid brake with better design and design control of the MR fluid design. To do so, four important steps have been accomplished. In the first step, a mathematical modeling of the conventional frictional brake and MR fluid brake has been developed to study and specify all design parameters. In the second step, a nondimensional, closedform analysis and a Taylor series expansion have used to examine the effects of perturbing dimensionless design parameters on the overall brakes performance. In the third step, two optimal designs for MR fluid brakes have been developed by taking advantage of sensitivity analysis and the design of experiments method also known as the Taguchi method. In the fourth step, controlling a MR fluid brake is performed by using two parallel PI controls for controlling the magnetic current and MR fluid thickness simultaneously. It was concluded that sensitivity analysis is a good method for identifying the parameters that have the greatest impact on brake performance and can be used as one method for the designer to obtain an optimal design. Four nondimensional design parameters were successfully used to describe the conventional frictional brake and seven nondimensional design parameters for MR fluid brake. Only two parameters for the conventional brake and five parameters for the MR fluid brake affect the performance and the others can be neglected. Two new designs for the MR fluid brake are presented and shown to be very simple in design, low in cost by removing a lot of additional auxiliaries for the frictional brake, and easy for control. By simultaneously controlling the MR fluid thickness and the electric current, a large range of brake torque is achieved without increasing the radial envelop for the brake, and saturation conditions in one controller are compensated for by the other controller. High angular velocities of the brake are primarily controlled by increasing the MR fluid thickness, while low angular velocities are primarily controlled by increasing the electric current. Good transient responses for regulating a constant speed (high, moderate, and low), and good stability while seeking to track a sinusoidal input have been achieved. In summary, the proposed control system for the MR fluid brake has demonstrated good controllability for the MR fluid brake.

Considerations for Finding the Optimal Design Parameters for a Novel Pole Climbing Robot

2008 ◽  
Author(s):  
Gabriel Goldman ◽  
Dennis Hong
Keyword(s):  
Optimal Design ◽  
Central Body ◽  
Design Parameters ◽  
Future Research ◽  
Climbing Robot ◽  
Serial Chain ◽  
Allowable Range ◽  
The Given ◽  
Selection Of ◽  
Do So

HyDRAS (Hyper-redundant Discrete Robotic Articulated Serpentine) is a novel serpentine robot comprising a serial chain of actuated universal joints for climbing structures such as poles or scaffoldings. To do so, it wraps its body around the structure in a helical shape, and rotates its body along its own central body axis to roll up the structure. This paper presents a method and considerations for selecting the optimal design parameters for the development of HyDRAS. The geometry equations derived in this paper will allow for a parametric approach that will aid in the selection of the appropriate design parameters such as module length, module diameter, helical pitch, and allowable range of motion for the given task of climbing pole like structures. Several examples are used to illustrate the method. The results obtained will be used in the analysis of the mechanical advantage of the mechanism and future research on the motion planning of HyDRAS.

Probabilistic Optimal Design Using Second Moment Criteria

1988 ◽  
Vol 110 (3) ◽  
pp. 324-329 ◽  
Author(s):  
A. D. Belegundu
Keyword(s):  
Finite Element Method ◽  
Sensitivity Analysis ◽  
Optimal Design ◽  
Design Sensitivity ◽  
Design Criterion ◽  
Second Order ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Programming Technique ◽  
Second Moment

Probability-based optimal design of structures is presented. The emphasis here is to develop a practical approach to optimal design given random design parameters. The method is applicable to structures which are modeled using the finite element method. The Hasofer-Lind (H-L) second-moment design criterion is used to formulate the general design problem. A method for calculating the sensitivity coefficients is presented, which involves second-order design sensitivity analysis. The importance of second order derivatives is established. A nonlinear programming technique is used to solve the problem. Numerical results are presented, where stiffness parameters are treated as random variables.

The Automobile Tension Bar Time-Varying Reliability Sensitivity Analysis

2014 ◽  
Vol 620 ◽  
pp. 143-147
Author(s):  
Shu Sen Liu ◽  
Bo Qiang Shi ◽  
Wen Yu Zhang ◽  
Xue Jie Fu ◽  
Yue Wei Wu
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Optimization Design ◽  
Design Parameters ◽  
Time Varying ◽  
Reliability Sensitivity ◽  
Reliability Sensitivity Analysis ◽  
Robust Optimal Design ◽  
Robust Optimization Design ◽  
The Impact

In this paper, the design of a automobile tension bar analysis example, the use of sensitivity analysis of time-varying reliability robust optimal design tension bar design parameters for reliability sensitivity analysis shows that the reliability of the impact of the strength of the material and rod diameter is positive, and the reliability of the impact of the load and rod diameter is negative. Correct application of time-varying reliability robust optimal design of mechanical parts when variant reliability robust optimization design, design service at any time during the period were not sensitive to changes of the design parameters of the reliability of the parts, and improve the parts reliability soundness.

scholarly journals Fundamental framework toward optimal design of product platform for industrial three-axis linear-type robots

2015 ◽  
Vol 2 (3) ◽  
pp. 157-164 ◽  
Author(s):  
Kana Sawai ◽  
Yutaka Nomaguchi ◽  
Kikuo Fujita
Keyword(s):  
Optimal Design ◽  
Optimization Problem ◽  
Performance Metrics ◽  
Beam Theory ◽  
Design Parameters ◽  
Product Platform ◽  
Linear Type ◽  
Operation Speed ◽  
Trade Offs ◽  
Wide Range

Abstract This paper discusses an optimization-based approach for the design of a product platform for industrial three-axis linear-type robots, which are widely used for handling objects in manufacturing lines. Since the operational specifications of these robots, such as operation speed, working distance and orientation, weight and shape of loads, etc., will vary for different applications, robotic system vendors must provide various types of robots efficiently and effectively to meet a range of market needs. A promising step toward this goal is the concept of a product platform, in which several key elements are commonly used across a series of products, which can then be customized for individual requirements. However the design of a product platform is more complicated than that of each product, due to the need to optimize the design across many products. This paper proposes an optimization-based fundamental framework toward the design of a product platform for industrial three-axis linear-type robots; this framework allows the solution of a complicated design problem and builds an optimal design method of fundamental features of robot frames that are commonly used for a wide range of robots. In this formulation, some key performance metrics of the robot are estimated by a reduced-order model which is configured with beam theory. A multi-objective optimization problem is formulated to represent the trade-offs among key design parameters using a weighted-sum form for a single product. This formulation is integrated into a mini–max type optimization problem across a series of robots as an optimal design formulation for the product platform. Some case studies of optimal platform design for industrial three-axis linear-type robots are presented to demonstrate the applications of a genetic algorithm to such mathematical models.

Optimal Design of a Conventional and Magnetorheological Fluid Brakes Using Sensitivity Analysis and Taguchi Method

2018 ◽  
Author(s):  
Salwan Obaid Waheed Khafaji ◽  
Noah D. Manring ◽  
Mohammed Al-Mudhafar
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Series Expansion ◽  
Numerical Models ◽  
Taylor Series Expansion ◽  
Magnetorheological Fluid ◽  
Design Parameters ◽  
Taguchi Approach ◽  
Dimensionless Groups ◽  
Braking Torque

Drum brakes have dominated the braking industry for many years due to their low cost and adequate operating performance. In this paper, the authors present the first example of studying the sensitivity analysis of a magnetorheological fluid (MRF) and a conventional frictional brake by using first order Tayler series expansion. Nondimensional analyses are carried out to generalize the analyses for every brake configuration. This paper seeks to step away from the complexity of the numerical models for these brakes. Taylor series expansion is used to examine the effects of perturbing dimensionless design parameters on the braking torque. In addition, Taguchi approach is applied for the brakes to study the contribution of the design parameters on the braking torque and to obtain the optimal design. It is shown in this paper that braking torque for magnetorheological fluid brake is dependent on seven dimensionless groups while the frictional brake is dependent upon only four dimensionless groups. Four groups of the MRF brake and two groups for the frictional brake dominate the physics of braking. The sensitivity analysis has identified the key parameters that must be adjusted in order to increase braking torque. Furthermore, Taguchi approach has showed the how the variations of input variables affect the variations of the output variable and stated the optimal levels of the design parameters that achieve the optimal design.

Justification of design parameters of the fractional reaping conveyor and its devices for removal of beveled stems from under the wheels of the vehicle

2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych
Keyword(s):  
Optimal Design ◽  
Technological Process ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Optimal Parameters ◽  
Belt Conveyor ◽  
Grain Crops ◽  
Mode Of Operation ◽  
Optimal Values ◽  
Main Component

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.

scholarly journals Optimal Design Parameters for a Phased Array Based Ultrasonic Polar Scan

2021 ◽  
pp. 1-1
Author(s):  
Jannes Daemen ◽  
Arvid Martens ◽  
Mathias Kersemans ◽  
Erik Verboven ◽  
Steven Delrue ◽  
...  
Keyword(s):  
Optimal Design ◽  
Phased Array ◽  
Design Parameters ◽  
Ultrasonic Polar Scan

scholarly journals Towards Reduced CNNs for De-Noising Phase Images Corrupted with Speckle Noise

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 255
Author(s):  
Marie Tahon ◽  
Silvio Montresor ◽  
Pascal Picart
Keyword(s):  
Phase Error ◽  
Speckle Noise ◽  
Experimental Conditions ◽  
Benchmark Data ◽  
Wide Range ◽  
Phase Images ◽  
Different Depths ◽  
Phase Data ◽  
Do So

Digital holography is a very efficient technique for 3D imaging and the characterization of changes at the surfaces of objects. However, during the process of holographic interferometry, the reconstructed phase images suffer from speckle noise. In this paper, de-noising is addressed with phase images corrupted with speckle noise. To do so, DnCNN residual networks with different depths were built and trained with various holographic noisy phase data. The possibility of using a network pre-trained on natural images with Gaussian noise is also investigated. All models are evaluated in terms of phase error with HOLODEEP benchmark data and with three unseen images corresponding to different experimental conditions. The best results are obtained using a network with only four convolutional blocks and trained with a wide range of noisy phase patterns.

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