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Showing 399 results for Sign


Volume 19, Issue 5 (9-2017)
Abstract

Sexing is a difficult task for most birds (especially ornamental birds) involving expensive, state-of-the-art equipment and experiments. An intelligent fowl sexing system was developed based on data mining methods to distinguish hen from cock hatchlings. The vocalization of one-day-old hatchlings was captured by a microphone and a sound card. To obtain more accurate information from the recordings, time-domain sound signals were converted into the frequency domain and the time-frequency domain using Fourier transform and discrete wavelet transform, respectively. During data-mining from signals of these three domains, 25 statistical features were extracted. The Improved Distance Evaluation (IDE) method was used to select the best features and also to reduce the classifier's input dimensions. Fowls’ sound signals were classified by Support Vector Machine (SVM) with a Gaussian Radial Basis Function (GRBF). This classifier identified and classified cocks and hens based on the selected features from time, frequency and time-frequency domains. The highest accuracy of the SVM at time, frequency and time-frequency domains was 68.51, 70.37 and 90.74 percent, respectively. Results showed that the proposed system can successfully distinguish between Hen and Cock hatchlings. The results further suggest that signal processing and feature selection methods can maximize the classification accuracy.

Volume 19, Issue 5 (12-2019)
Abstract

The tubular structures are having the capability of resisting wind and earthquake loads with the exterior tube system. Tube systems consist of closely spaced exterior columns and deep beams around the corner of the plan that provides sufficient rigidity and stability for tall/high-rise buildings. Another advantage of the tubular system is the significant reduction in the building materials and increasing the architectural space in the internal plan. The mentioned cases have increased the popularity of this kind of structural system. But the most important problem in the tube system is the shear lag. Shear lag is the non-uniform distribution of stress on the face columns when the tube system is subjected to lateral loads. Shear lag can occur in any box-shaped structural system that is loaded laterally.  Shear lag increases structural displacement, limiting the use of maximum structural capacity and causing warping of the floors.
The purpose of this research is to study the effects of shear lag on the tube system and find how to reduce shear lag. In order to do this, a tubular structure is analyzed and designed based on the Capacity Design Approach and Performance Base Design with the LATBSDC, ASCE 7-16, and AISC 360-10. To evaluate the seismic performance of the tubular structure and braced tube structure, the Nonlinear Dynamic Procedure (NDP) for two ground motion intensity levels based on LATBSDC is used. Nonlinear dynamic response analyses for two earthquake ground motion intensities done and acceptability criteria demonstrated. In the next step shear lag in the designed structures is investigated. Also, the relationship between shear lag and the stiffness of the peripheral beams is studied. The result shows that increasing peripheral beam stiffness is not a good way to reduce the effects of shear lag because of economic issues. Also, other proposed methods, such as the addition of core or internal tubes, are not a suitable solution to reduce the effects of shear lag, given the high cost they impose on the project.
Due to the development process and the effect of shear lag on tubular structures, adding braces to one-fifth of the height of the structure in lower floors have been proposed to reduce the effects of shear lag. In order to calculate the shear lag, the distribution of axial stress in the tubular structure columns is considered as the basis and compared with the axial stresses of the columns in the proposed system. The proposed tube system and tube system have been analyzed by different levels of earthquakes and compared for performance purposes. In all the analysis and evaluations carried out in this study, the performance and behavior of the proposed systems were better than the tubular structure. With the addition of braces to one-fifth of the height of the structure in lower floors, the stress in the corner columns has been significantly reduced. The proposed system has been able to significantly reduce the shear lag. Therefore, in order to reduce shear lag and achieve proper behavior in tube systems, it is recommended to use the proposed systems in this study.
 


Volume 19, Issue 7 (7-2019)
Abstract

Measuring the vital signs of human body, such as oxygen saturation, blood pressure, and heart rate is the greatest and basic stage of the diagnosis of various diseases, especially cardiovascular diseases. Various methods have been developed to measure these signs. In general, these methods are divided into invasive and non-invasive categories. Due to less damages of non-invasive methods, more attention has been paid to them in recent decades. Using mobile phone is one of the most important non-invasive approaches because of being common and accessible among people. In this article, after studying Photoplethysmographic methods and expressing theories related to this method, imaging photoplethysmography (IPPG) is used to measure heart rate. Regarding two proposed algorithms based on furies transfer and peak detection, implementation of these algorithms was done, using a camera and LED of smart phone on 20 people. Next, the heart was calculated. Finally, a comparison was made between the two methods, the results of which show that peak detection method has less error than furies transfer method.



Volume 19, Issue 8 (8-2019)
Abstract

In this paper, in order to minimize the required power of satellite thermal control subsystem, considering known geometric model and the orbital parameters and conditions, the optimal layout design of the satellite subsystems will be performed based on thermal and attitude control constraints. Since all of the satellite subsystems can act only in a certain temperature range, here, by considering the thermal dissipations of each subsystem and incoming thermal loads to each satellite faces in different orbital conditions, by optimally layout of components and sub-systems of the satellite, we will arrive to appropriate configuration plan. The constraints of the thermal subsystem should be satisfied by considering the temperature distribution within the satellite as far as possible. Finally, given that the main purpose of this layout is to provide thermal power, in addition to satisfication of the power budget system constraint, the power of the thermal control subsystem has been reduced by 66%. The superiority of this method is that by following the resulting layout, we obtain a model that needs a thermal control subsystem with less complexity and limited power. Consequently, in addition to decreasing the mass of the satellite, reliability will also be increased. Considering the importance of satellite stability, the layout algorithm and optimization are defined in such a way that the attitude control requirements are observed with the thermal requirements in this layout.


Volume 19, Issue 10 (10-2019)
Abstract

Shape memory alloys (SMAs) are a new generation of smart materials which was the subject of researches in recent years. In this study, SMAs are employed to improve the vibrational and structural behavior of composite beams. A numerical solution was presented for natural frequency analysis of the clamped-clamped beam and the obtained results were validated with results of available references. Two main goals were followed in this study: first, analysis the influences of effective design parameters of embedded SMA wires on natural frequencies of composite beams and second, optimal design of SMAs to improve the vibrational and structural behavior of composite beam. In the first step, the effect of design parameters of shape memory alloy wires including the number and the diameter of wires on natural frequencies and total mass of structure was studied. In the second step, maximization of the first natural frequency of the structure and minimization of the total weight of the structure was the objective function of multi-objective optimization process which was performed by employing the genetic algorithm and weighted sum optimization approach. The obtained results of optimization processes confirmed the high efficiency of the proposed approach to improve the vibrational and structural properties of Shape memory alloys composite beam.


Volume 19, Issue 11 (11-2019)
Abstract

Despite the intense development of cable-driven robot in recent years, they have not yet been vastly utilized in their potential applications because of difficulties in their performing accurate installation and calibration. This paper aims to present a suitable control method, relieving the limitation of accurate calibration and installation requirement in the suspended cable-driven parallel robot. In this paper, kinematics and dynamics uncertainties are investigated and based on their bounds, a robust controller is proposed. The main innovation of this article is providing a new control method to cost reduction by eliminating accurate measurement tools such as a camera in position control of a deployable cable-driven robot. Using this approach, reducing costs in building a robot and increasing the speed of installation and calibration is achieved. Another problem investigated in this paper is the problem of joint space controllers applied to redundant cable-driven parallel robots, namely the loosened redundant cable. To solve this problem, the embedded force sensor and a new sliding surface for the controller is proposed. In fact, in this paper, the conventional joint-space controllers are modified to become applicable to the control of cable-driven robots. Finally, by conducting some experiments using ARAS suspended cable-driven parallel robot, the proposed algorithms are verified and it is shown that there are feasible solutions for stable robot maneuvers.


Volume 19, Issue 12 (12-2019)
Abstract

In this paper, the effect of the Gurney flap parameters such as the angle of attack, Reynolds number, angle and height of the flap and its location from the escape edge on the lift coefficient of a symmetric airfoil is considered with the help of simulation in computational fluid dynamic software of Fluent. The turbulence model k-ε is used for the two-dimensional domain. Also, the value of the lift coefficient is introduced as a function of effective parameters by the design of experiment (DOE) method and using the backward elimination regression model which is a statistical method for selecting the model and estimated error terms. The value of the airfoil lift coefficient can be determined and predicted by the obtained function. The numerical values derived from the function of the lift coefficient resulted from the design of experiment method are in good agreement with other valid papers. The results show that at the constant attack angle by increasing Gurney flap height, lift coefficient increase. On the other hand, at the constant height of the Gurney flap, this coefficient decreases with increasing angle of attack. Moreover, the lift coefficient increased by increasing the distance of the Gurney flap from the airfoil escape edge at a 90-degree angle and 1.5%, as well as increasing the Reynolds number at a constant height of a Gurney flap.


Volume 19, Issue 125 (7-2022)
Abstract


Nowadays, by converting the cheap and commercial low-valued fish into value-added products such as fish sausages, as well as the application of novel ohmic heating method to cook more uniform, faster compared to other thermal severe methods and with minimal processing can play an important role in producing a safe and nutritious product. Therefore, the purpose of this study is to investigate some microbial and chemical characteristics of (Saurida tumbil) greater lizardfish sausage heated by emerging ohmic heating method and formulation optimization was performed by response surface methodology -central composite design (RSM-CCD) by considering KCl (0.7- 2.3 %), Soy Oil ( 4-14 %) and Isolated Soy Protein (0.2-1.8%). Optimization of 20 fish sausage formulation produced by ohmic heating was done by response surface methodology using Design Expert software version 11 and the relationship between the independent variables and the five responses was investigated. KCl has been shown an inhibitory effect on samples total plate count level. The interaction effect of soybean oil and soy protein isolate had a significant effect on pH changes. Increasing soybean oil percentage caused a little increase and subsequently reduction of pH and increasing soy protein isolate led to a significant decrease in pH. Furthermore, higher amount of KCl and soy protein isolate reduced the amount of cooking loss. In addition increase of soy bean oil percentage caused reduction and increase of soy protein isolate lead to increase of water holding capacity. Based on the results of formulation optimization in fish sausages with formulations containing 2% potassium chloride, 6% soybean oil and 1.5% soy protein isolate can increase water holding capacity, the lowest microbial load and the lowest peroxide value, cooking loss and optimized pH.
 

Volume 19, Issue 126 (8-2022)
Abstract

Additives analysis plays important role in food quality control and has a great impact on public health. Therefore, rapid detection of these compounds in food samples is important in food safety. In this study, reduced graphene oxide /Fe3O4 nanocomposite (rG-Fe3O4-NC) was synthesized in the presence of sour lemon peel extract as a reducer and stabilizer agent in aqueous solution. For the first time multivariate optimization based on rotatable central composite design (RCCD) coupled with response surface methodology (RSM) was used to optimize effective experimental variables for fabrication of electrode. An experimental design has been used to examine and optimize the impacts of diverse experimental parameters like the pH and concentration of the nanocomposite in rG-Fe3O4-NC. The optimal conditions were pH: 6 and the concentration of the nanocomposite: 8%. The synthesized nanocomposites were characterized by TEM and XRD techniques. The rGO modified carbon paste electrode (rG-Fe3O4-NC/CPE) was used as a highly sensitive electrochemical sensor for the detection of vanillin. Interference of vitamin B2, methionine, valine, glycine and KBR, KCl and glucose were checked in the presence of 25 µM vanillin at surface of rG-Fe3O4-NC/CPE with acceptable error 5%. Results confirmed that 500-folde of above compounds have not any important interference in monitoring process of 25 µM vanillin. The vanillin sensor showed linear range between 01 nM – 250 μM and a low detection limit of 0.3 nM. Finally, the rG-Fe3O4-NC/CPE was successfully used for determining vanillin in food samples. Therefore, this sensor can be used in food industry to the online determination of vanillin in flavored milks and ice cream.

Volume 19, Issue 133 (2-2023)
Abstract

The use of nanotechnology in the food industry provides facilities such as encapsulation, targeted transfer of plant compounds and extracts without unfavourable sensitive effects. In this study, the essential oil (EO) of Santalum album (Santalum album linn.) was used to prepare a nanoemulsion. The nanoemulsion characteristics were evaluated and the data was optimized. To conduct the research, Design-Expert 12, statistical method of response surface, Central composite design with variables such as ultrasound frequency (25-31 kHz), ultrasound duration (10-20 sec.), and Santalum album EO (1%-10%) were used. After extraction of EO and identification of its effective compounds; percentage of antioxidant activity, viscosity, color indexes and the particle size of nanoemulsions tests were done. After optimization, stability test was performed on the optimized sample. The optimization results showed that with 5.5% Santalum album EO, ultrasound frequency of 28 KHZ, ultrasound duration of 15 seconds a nanoemulsion having optimum characteristics can be produced. After repeating the experiments for the obtained point, resulted in production of a nanoemulstion having particle size of 230 nm, the viscosity of 3.10 mPa.s, the brightness index of 78, the whiteness index of 58, and the antioxidant activity of 70%. It is believed these nanoemulsions have the potential to be used in the cosmetics, pharmaceutical and food industries.
 

Volume 20, Issue 1 (1-2020)
Abstract

Grain design is the most important part of a solid rocket motor. The aim of this study is finocyl grain design based on predetermined objective function with respect to ballistic curves in order to satisfy various thrust performance requirements through an innovative design approach using a genetic algorithm optimization method. The classical sampling method has been used for design space-filling. The level set method has been used for simulating the evolution of the burning surface in the propellant grain. An algorithm has been developed beside the level set code that prepares the initial grain configuration using Pro/Engineer software to export generated models to level set code. The lumped method has been used to perform internal ballistic analysis. Two meta-models are used to surrogate the level set method in the optimization design loop. The first method is based on adaptive basis function construction and the second method is based on the artificial neural network. In order to validate the proposed algorithm, a grain finosyl sample has been investigated. The results show that both grain design method reduced the design time significantly and this algorithm can be used in designing of any grain configuration. In addition, data have more accuracy in grain design based on the artificial neural network, so this method is the more effective and practical method to grain burn-back training.



Volume 20, Issue 1 (4-2020)
Abstract

Drop vortex is utilized to convey sewage across elevation change in steep catchments. This structure is generally used when the elevation difference is more than 5 m. Since the air and water flow are extensively combined in these structures and the sewage flow might contain detergent and foam producing materials, foam could produce in some parts of drop vortex. This phenomenon could affect vortex airflow and reduce drop vortex hydraulic performance. In this investigation, the effects of Foam Producing Flow (FPF) on vortex air discharge were studied by a scaled model and statistical Design of Experiment (DoE) methodology. Effects of Concentration Number, detergent type, and Froude Number on the dependent variable, air discharge to water discharge ratio, were studied by 33 full-factorial design and 63 runs. Analysis of the results revealed that all design factors had meaningful effects on vortex air discharge and it decreases by the increase of Concentration and Froude Number. Moreover, it was illuminated that foam formation could boost air discharge by 82% and in some conditions could reduce it more than 64%.



Volume 20, Issue 2 (5-2020)
Abstract

The RCC construction method is one of the alternative methods in constructing concrete and earth dams. RCC is a kind of concrete which is pressed with roller, and after being compacted with roller, it is changed to a concrete like normal concrete .Primarily, using RCC in dam construction was developed to obtain the concrete structural properties and a construction method similar to earth dams. In RCC mix design, compressibility, non-segregation, maintaining the consistency of the fresh concrete, limiting the permeability, and achieving the proper bonding among the layers is required for efficiency .A qualitatively and quantitatively wide range of materials are used for constructing RCC mixtures in different dam projects. Therefore،Primarily the RCC aimed to obtain the conventional concrete properties and the construction procedure similar to earth dams. The quality and accessibility to materials to produce RCC should satisfy the structural and durability requirements. Therefore, the proper ratio of roller compacted concrete Mixture is an important step in achieving an economical and durable concrete.  This study aims to investigate the effects of various factors on the dam RCC Mixture Design (a case study of Javeh dam in the West of Iran), which optimum Mixture Design was developed as a laboratory research while observing all technical requirements and finally it was conducted as a test pad application. Javeh Reservoir Dam is located in a distance of 40 km southwest of Sanandaj, Kurdistan and 6 km from the downstream of Gaveh Roud and Qeshlaq River intersection. The dam is made of RCC. The properties of RCC in fresh and hardened conditions are of particular importance. Technical and economic advantages of RCC dams depend on the suitability of the mix design. Therefore, by an appropriate mix design, we can investigate the effect of RCC composite materials on the strength properties of RCC in terms of compressive strength, efficiency and non-separation characteristics of aggregates and their ratios in an optimal mix design. RCC must have sufficient efficiency to achieve the desired density according to the method and facilities. The efficiency of the new mix of RCC is entirely influenced by the amount of paste in the RCC mix. The paste contains the materials finer than #200 sieve including cement, pozzolan, water, filler of the aggregates and air bubbles. From the results, the total cementitious materials used in the optimum laboratory Mixture Design is 125 kg/m3. In addition, the ratio of Paste to mortar was about 5% higher than the minimum recommended in the RCC instruction given in the manual of the US Army Corps of Engineers. The compressive strength of roller concrete is affected by factors such as the amount of aggregates, the quality of fine grains, the quality of cement materials, grade density and content of mixed moisture. Considering that artificial neural networks are among the modeling methods that have shown great power to adapt to engineering problems, the models for predicting the compressive strength of this type of 180-day concrete is discussed based on the actual results from laboratory Mixture Design by neural networks modeling. The values of correlation coefficients in each of the models made in this study were close to the value of 1, which indicates the appropriate accuracy of the models.
 

Volume 20, Issue 3 (5-2018)
Abstract

Iranian famous drinking yoghurt type, named Doogh, is a fermented dairy beverage and constituts an important part of daily beverage consumption in Iran. Doogh is commonly produced from mixing of yoghurt, drinking water, salt, and essence of aromatic vegetables such as thyme, mint, and oregano. In the present work, the effects of Quince seed mucilage [Qm: 0-0.1% (w/w)], Guar gum [Gg: 0-0.2% (w/w)] and storage time (1-21 days) on the physicochemical (pH, acidity and viscosity) and sensory properties of Doogh were studied. The Doogh was stored at 4°C for 21 days to be evaluated. Quince seed mucilage and guar gum were added to Doogh based on a Central Composite Design (CCD). The Response Surface Method (RSM) was applied to find out the optimum conditions and interaction between different factors. Three factors including Doogh storage time and added percentages of Qm and Gg were investigated. The results showed that the optimum condition of factors was different based on response. Based on viscosity of the Doogh, the first day of Doogh production and 0.1% (w/w) of Qm and 0.2% (w/w) of Gg were the best condition.

Volume 20, Issue 3 (2-2020)
Abstract

In this study, a selective laser sintering 3D printer has been designed and built. 3D laser printing is one of the flexible additive manufacturing methods, which can use different powdered materials. Recently, additive manufacturing technologies have been introduced into the pharmacy, and in August 2015, they received FDA approval as the three-dimensional drug products. By using additive manufacturing in the pharmacy, controlled release, dosage tailored to the characteristics of individuals, the desired morphology of the drugs can be achieved and we move toward the personalization of the medicine. One of the important issues is to determine the properties of tablets before printing. In this paper, the effect of important variables of selective laser sintering on tablet breaking force is investigated with the aid of central composite design and modeling. Using the proposed modeling, the value of each variable can be determined so that the tablets are printed with the required breaking force. The cylindrical tablets with a diameter of 1.2 cm and a height of 3.6 mm were printed for use in the experiments. To fabricate tablets, the thermoplastic polymer, Kollicoat IR (75% polyvinyl alcohol and 25% polyethylene glycol copolymer), was used and 5% paracetamol (acetaminophen) was added. Also, some edible black color was added to increase the absorption of laser light. Laser feed rate, the percentage of the tablet infill density and percentage of the added color are the studied variables. According to the results obtained in the considered range, by increasing laser feed rate, tablet breaking force decreases, but tablet braking force increases by increasing infill density and amount of added color.


Volume 20, Issue 3 (2-2020)
Abstract

This competitive commercial space forces designers and manufactures to produce and supply products with high quality and low prices at a desirable level of reliability. On the other hand, during the design and production process, engineers are always faced with uncertainty. In recent years, to encounter these uncertainties and guarantee the quality and reliability of a system subsequently, reliability-based robust design optimization (RBRDO) algorithms have been developed based on robust design optimization (RDO) and reliability-based optimization (RBDO). In practical engineering, uncertainties of some design parameters or variables are epistemic and only a few samples are available for designer. Generally, some of the RBRDO methods ignore the information in the design process. This approach can lead to an enormous error. Other RBRDO methods ignore this valuable information in the design process. This study, a comprehensive RBRDO framework is developed by combining Bayesian reliability analysis and dimensionality reduction method (DRM) using NSGA2-II multi-objective optimization algorithm. For verification of the proposed algorithm, an engineering example is selected and the effects of epistemic uncertainty on objectives are studied. Moreover, the results of the proposed approach are compared with other existing approaches at a specific case of available data about epistemic uncertainty.


Volume 20, Issue 3 (2-2020)
Abstract

Additive manufacturing technology significantly simplifies the production of complex 3D parts directly by the computer-aided design model. However, additive manufacturing processes have unique flexibility. They still have restrictions that don’t allow engineers to generate some specific geometric shapes, easily. Some of these restrictions are the consumption of materials to supports, the poor abrasion resistance and the inferior surface finish of some surfaces with certain angles. One of the methods to overcome these problems is designing by segmentation. The proposed methodology consists of two steps: 1) segmenting of the 3D model and 2) exploring the best orientation for each segment. In the first step, engineers consider the possible number of segments and the connection method of segments. In this paper, a series of segments is obtained by recognition of features and separating them with one or more appropriate planes. In the second step, the best fabrication orientation should be chosen. The criterion for optimization is that the support volume, abrasion ability, and surface roughness should be minimum. The operation is performed automatically by the algorithm created based on principles of the Particle swarm optimization algorithm using visual C#. Experimental tests show that segmentation design improves additive manufacturing processes from the aspects of material consumption, abrasion volume, and surface quality. This paper presents an original approach to improving the efficiency of additive manufacturing technologies that make the additive manufacturing closer to maturity.


Volume 20, Issue 3 (2-2020)
Abstract

In this paper, the design and construction of a new binary pneumatic actuated hyper-redundant manipulator is presented. The discretely actuated hyper-redundant manipulators have advantages such as wide workspace, the ability of obstacle avoidance and simple control. Despite of these advantages, few prototypes have been made so far, which each of them has some defects. These defects are small movement range, fairly high cost, and accelerated and impulsive motion. To solve these problems, the 3-revolute prismatic spherical parallel mechanisms (3-RPS) are used as modules in this paper. So the cost is reduced due to the lower number of legs. Also, the motion range has been increased by replacing the spherical joints with universal joints. The movements of the manipulator have been effectively more uniform and softer by using flow control valves on cylinders. Finally, several tests are conducted to determine how the manipulator moves and the results are presented.


Volume 20, Issue 3 (10-2020)
Abstract

According to the vital role that bridges play in transportation system and also communications of a society, monitoring their structural safety and keeping theme in service is crucial. Numerous methods have been proposed for detecting probable damages in bridges. Unfortunately most of them are based on comparison between the response of bridge in an intact and damaged state. Therefore intact state response must be known. However, not always it’s true in practice. So proposing a method which can determine and localize damages without prior knowledge of intact state is necessary. Such a method which was proposed by Sun et al. is studied carefully. Through the aforementioned method, the dynamic displacement response of a simply supported beam was decomposed into a dynamic component and a quasi-static component. Using Maxwell-Betti law of reciprocal deflection, the quasi-static component was attributed to the static deflection of the beam. Later damage which is defined by loss of stiffness, could be localized based on the abrupt changes in the static deflection curvature as it is related to bending moment and flexural stiffness of a beam. It is found out that the decomposition approach proposed by Sun et al. is restricted to fact that only one mode of oscillation must be dominant and also the natural frequency of motion must be determined through experimental measuring. Another limitation is that the abrupt changes in the curvature diagram cannot be related to damage essentially as curvature is also affected by the bending moment. In this study two modifications were proposed to get more accurate results in localizing the imposed damages. The first modification is the use of EMD method in order to decompose the displacement response into its intrinsic mode functions. Hence the aforementioned method could be used in real bridge displacement responses as higher modes corporations can also be determined and extracted through EMD process and finally the quasi-static component is determined as the residue of EMD algorithm. Also the ambient noise may be decomposed from the original signal, improving the method to work in real situations. The second modification is creating an imaginary constant moment length in the beam by the use of super position principle. So sudden increase in the curvature diagram is essentially a damage. Different scenarios of damage were studied and both methods have been used to detect damage in each scenario. Results show a great improvement in detection and localization of damage using the improved algorithm rather than the original proposed method. Eventually a five span real bridge model was taken into study. The improved damaged detection method could clearly determine the longitudinal position of the damage.

Volume 20, Issue 4 (4-2020)
Abstract

In this paper, a new active vibration control system has been proposed for the elimination of boring bar chatter in the internal turning process. The system is composed of a boring bar equipped with electromagnetic actuator and accelerometer, as well as a novel adaptive control algorithm that is widely used in the field of active noise control. The controller is known as feedback FxNLMS and is composed of two finite impulse response adaptive filters. One of the filters is known as a model filter, which predicts the dynamic model of actuator-boring bar assembly. The other is known as the control filter and anticipates the inverse model of forwarding path dynamics. The weight vector of the adaptive filter is adjusted by using the normalized least mean square algorithm. Firstly, the impact test is conducted in the presence of an adaptive controller. It is observed that the magnitude of the dominant mode on the forward path’s frequency response function is drastically suppressed by 36 dBs. Secondly, the internal turning tests are conducted on Aluminum alloy 6063-T6, to investigate the performance of the adaptive controller for the purpose of chatter mitigation. Due to the optimal performance of the adaptive controller, the dominant magnitude of the boring bar’s power spectral density is successfully attenuated up to 68 dBs, and the critical limiting depth of cut is increased by 10 folds. Also, the roughness of the machined surface is remarkably improved by 8 folds compared to the control-off cutting test. Moreover, the actuator cost is considerably reduced by 3 folds in comparison to the optimal constant-gain integral controller.


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