A nonsingular optimization approach to the feed rate profile optimization of fedbatch cultures

2001 ◽  
Vol 24 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Kim S. ◽  
Lee J. ◽  
Lim H.
Keyword(s):  
Feed Rate ◽  
Optimization Approach ◽  
Profile Optimization ◽  
Rate Profile

scholarly journals Reducing the Frame Vibration of Delta Robot in Pick and Place Application: An Acceleration Profile Optimization Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Hongtai Cheng ◽  
Wei Li
Keyword(s):  
Surrogate Model ◽  
High Speed ◽  
Gaussian Process Regression ◽  
Frame Structure ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
Pick And Place ◽  
Delta Robot ◽  
Profile Optimization ◽  
Acceleration Profile

Delta robot is typically mounted on a frame and performs high speed pick and place tasks from top to bottom. Because of its outstanding accelerating capability and higher center of mass, the Delta robot can generate significant frame vibration. Existing trajectory smoothing methods mainly focus on vibration reduction for the robot instead of the frame, and modifying the frame structure increases the manufacturing cost. In this paper, an acceleration profile optimization approach is proposed to reduce the Delta robot-frame vibration. The profile is determined by the maximum jerk, acceleration, and velocity. The pick and place motion (PPM) and resulting frame vibration are analyzed in frequency domain. Quantitative analysis shows that frame vibration can be reduced by altering those dynamic motion parameters. Because the analytic model is derived based on several simplifications, it cannot be directly applied. A surrogate model-based optimization method is proposed to solve the practical issues. By directly executing the PPM with different parameters and measuring the vibration, a model is derived using Gaussian Process Regression (GPR). In order to reduce the frame vibration without sacrificing robot efficiency, those two goals are fused together according to their priorities. Based on the surrogate model, a single objective optimization problem is formulated and solved by Genetic Algorithm (GA). Experimental results show effectiveness of the proposed method. Behavior of the optimal parameters also verifies the robot-frame vibration mechanism.

Quintic Spline Interpolation With Minimal Feed Fluctuation

2005 ◽  
Vol 127 (2) ◽  
pp. 339-349 ◽  
Author(s):  
Kaan Erkorkmaz ◽  
Yusuf Altintas
Keyword(s):  
Real Time ◽  
Feed Rate ◽  
Tool Path ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Tracking Error ◽  
Arc Length ◽  
Quintic Spline ◽  
Rate Profile ◽  
Spline Parameter

This paper presents a parameterization and an interpolation method for quintic splines, which result in a smooth and consistent feed rate profile. The discrepancy between the spline parameter and the actual arc length leads to undesirable feed fluctuations and discontinuity, which elicit themselves as high frequency acceleration and jerk harmonics, causing unwanted structural vibrations and excessive tracking error. Two different approaches are presented that alleviate this problem. The first approach is based on modifying the spline tool path so that it is optimally parameterized with respect to its arc length, which allows it to be accurately interpolated in real-time with minimal complexity. The second approach is based on scheduling the spline parameter to accurately yield the desired arc displacement (hence feed rate), either by approximation of the relationship between the arc length and the spline parameter with a feed correction polynomial, or by solving the spline parameter iteratively in real-time at each interpolation step. This approach is particularly suited for predetermined spline tool paths, which are not arc-length parameterized and cannot be modified. The proposed methods have been compared to approximately arc-length C3 quintic spline parameterization (Wang, F.-C., Wright, P. K., Barsky, B. A., and Yang, D. C. H., 1999, “Approximately Arc-Length Parameterized C3 Quintic Interpolatory Splines,” ASME J. Mech. Des, 121, No. 3., pp. 430–439) and first- and second-order Taylor series interpolation techniques (Huang, J.-T., and Yang, D. C. H., 1992, “Precision Command Generation for Computer Controlled Machines,” Precision Machining: Technology and Machine Development and Improvement, ASME-PED 58, pp. 89–104; Lin, R.-S. 2000, “Real-Time Surface Interpolator for 3-D Parametric Surface Machining on 3-Axis Machine Tools,” Intl. J. Mach. Tools Manuf., 40, No.10, pp. 1513–1526) in terms of feed rate consistency, computational efficiency, and experimental contouring accuracy.

scholarly journals Drilling Parameters Analysis on In-Situ Al/B4C/Mica Hybrid Composite and an Integrated Optimization Approach Using Fuzzy Model and Non-Dominated Sorting Genetic Algorithm

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2060
Author(s):  
Palanikumar Kayaroganam ◽  
Velavan Krishnan ◽  
Elango Natarajan ◽  
Senthilkumar Natarajan ◽  
Kanesan Muthusamy
Keyword(s):  
Genetic Algorithm ◽  
Feed Rate ◽  
Rotational Speed ◽  
Metal Matrix ◽  
Thrust Force ◽  
Performance Indicator ◽  
Hybrid Composites ◽  
Input Parameter ◽  
Optimization Approach

In-situ hybrid metal matrix composites were prepared by reinforcing AA6061 aluminium alloy with 10 wt.% of boron carbide (B4C) and 0 wt.% to 6 wt.% of mica. Machinability of the hybrid aluminium metal matrix composite was assessed by conducting drilling with varying input parameters. Surface texture of the hybrid composites and morphology of drill holes were examined through scanning electron microscope images. The influence of rotational speed, feed rate and % of mica reinforcement on thrust force and torque were studied and analysed. Statistical analysis and regression analysis were conducted to understand the significance of each input parameter. Reinforcement of mica is the key performance indicator in reducing the thrust force and torque in drilling of the selected material, irrespective of other parameter settings. Thrust force is minimum at mid-speed (2000 rpm) with the lowest feed rate (25 mm/min), but torque is minimum at highest speed (3000 rpm) with lowest feed rate (25 mm/min). Multi-objective optimization through a non-dominated sorting genetic algorithm has indicated that 1840 rpm of rotational speed, 25.3 mm/min of feed rate and 5.83% of mica reinforcement are the best parameters for obtaining the lowest thrust force of 339.68 N and torque of 68.98 N.m. Validation through experimental results confirms the predicted results with a negligible error (less than 0.1%). From the analysis and investigations, it is concluded that use of Al/10 wt.% B4C/5.83 wt.% mica composite is a good choice of material that comply with European Environmental Protection Directives: 2000/53/CE-ELV for the automotive sector. The energy and production cost of the components can be very much reduced if the found optimum drill parameters are adopted in the production.

scholarly journals Utility-Taguchi based hybrid optimization approach in machining of graphite composites

2021 ◽  
Vol 13 (1) ◽  
pp. 10-16
Author(s):  
Jogendra Kumar ◽  
Prakhar Kumar Kharwar ◽  
Rajesh Kumar Verma
Keyword(s):  
Performance Optimization ◽  
Feed Rate ◽  
Removal Rate ◽  
Hybrid Optimization ◽  
Confirmatory Test ◽  
Optimization Approach ◽  
Taguchi Approach ◽  
Machining Performance ◽  
Fiber Volume ◽  
Volume Percentage

In the present scenario, composites material is widely used in various engineering areas like satellite components, aircraft parts, chemical and sports industries. Graphite is an allotrope of carbon that possesses various electrical and mechanical properties. In this paper, graphite is taken as reinforcement into the epoxy matrix. In this study, the hybrid optimization module is developed to tackle multi-objective machining performance optimization issues. Utility concept coupled Taguchi approach is used to find out optimum values of responses in three input factors i.e., drill speed, feed rate and fiber volume percentage varied at four discrete levels and surface roughness (Ra) and material removal rate (MRR) are taken as process response. Taguchi L16 OA has been used to perform the machining operation. Multiple responses aggregated into a single function i.e., overall utility (U) and finally optimized by the Taguchi concept. Utility embedded Taguchi approach determined the favorable machining setting which the confirmatory test has verified shows satisfactory results. ANOVA outcomes reveal that feed rate (73.37%) is the most important factor trailed by drill speed (3.44%) and fiber volume percentage.  

Direct Compensator Profile Optimization for Intensity Modulated Radiation Therapy Treatment Planning

2009 ◽  
Author(s):  
Kevin J. Erhart ◽  
Eduardo A. Divo ◽  
Alain J. Kassab
Keyword(s):  
Radiation Therapy ◽  
Treatment Planning ◽  
Intensity Modulated Radiation Therapy ◽  
External Beam Radiation ◽  
Background Information ◽  
Optimization Approach ◽  
Treatment Technique ◽  
Beam Radiation ◽  
Intensity Modulated ◽  
Profile Optimization

Radiation therapy is a widely used and highly effective technique for the treatment of cancer, however the commissioning and delivery of a course of external beam radiation is a complex process with numerous challenges. This paper will present new developments that aim to improve both the planning and delivery of this important cancer treatment technique. Specifically, this work develops a new direct delivery parameter optimization approach for planning of solid compensator intensity modulated radiation therapy, coined Direct Compensator Profile Optimization (DCPO). In order to understand the benefits and implications of this new DCPO approach, a reasonable understanding of the field of radiation therapy is needed. Therefore, this document will include a brief discussion of the history and relevant background information in the area of radiation therapy. It is intended that this background information is detailed enough so that the remainder of this research can be followed by those without existing experience in the field of radiation treatment planning. The specific details of this new approach will be then be presented followed by a display of initial results to verify the performance.

Optimal Feed-Rate Scheduling for High-Speed Contouring

Manufacturing ◽  
2003 ◽  
Author(s):  
J. Dong ◽  
J. A. Stori
Keyword(s):  
Feed Rate ◽  
High Speed ◽  
Dynamic Models ◽  
Contour Error ◽  
Optimal Feed ◽  
Complex Trajectory ◽  
Rate Optimization ◽  
Rate Profile ◽  
Following Error ◽  
Feed Rate Optimization

The majority of efforts to improve the contouring performance of high-speed CNC systems have focused on advances in feed-back control techniques at the single-axis servo level. Regardless of the dynamic characteristics of an individual system, performance will inevitably suffer when that system is called upon to execute a complex trajectory beyond the range of its capabilities. The intent of the present work is to provide a framework for abstracting the capabilities of an individual multi-axis contouring system, and a methodology for using these capabilities to generate a time-optimal feed-rate profile for a particular trajectory on a particular machine. Several constraints are developed to drive the feed-rate optimization algorithm. First, simplified dynamic models of the individual axes are used to generate performance envelopes that couple the velocity vs. acceleration capabilities of each axis. Second, bandwidth limitations are introduced to mitigate frequency related problems encountered when traversing sharp geometric features at high velocity. Finally, a dynamic model for the instantaneous following error is used to estimate the contour-error as function of the instantaneous velocity and acceleration state. We present a computationally efficient algorithm for generating a minimum-time feed-rate profile subject to the above constraints, and demonstrate that significant improvements in contouring accuracy can be realized through such an approach. Experimental results are presented on a conventional two-axis X-Y stage executing a complex trajectory.

scholarly journals Optimization and Analysis of Surface Roughness, Flank Wear and 5 Different Sensorial Data via Tool Condition Monitoring System in Turning of AISI 5140

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4377 ◽  
Author(s):  
Mustafa Kuntoğlu ◽  
Abdullah Aslan ◽  
Hacı Sağlam ◽  
Danil Yurievich Pimenov ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Life ◽  
Feed Rate ◽  
Cutting Speed ◽  
Tool Condition Monitoring ◽  
Depth Of Cut ◽  
Optimization Approach ◽  
Machining Parameters ◽  
Tool Condition ◽  
Condition Monitoring System

Optimization of tool life is required to tune the machining parameters and achieve the desired surface roughness of the machined components in a wide range of engineering applications. There are many machining input variables which can influence surface roughness and tool life during any machining process, such as cutting speed, feed rate and depth of cut. These parameters can be optimized to reduce surface roughness and increase tool life. The present study investigates the optimization of five different sensorial criteria, additional to tool wear (VB) and surface roughness (Ra), via the Tool Condition Monitoring System (TCMS) for the first time in the open literature. Based on the Taguchi L9 orthogonal design principle, the basic machining parameters cutting speed (vc), feed rate (f) and depth of cut (ap) were adopted for the turning of AISI 5140 steel. For this purpose, an optimization approach was used implementing five different sensors, namely dynamometer, vibration, AE (Acoustic Emission), temperature and motor current sensors, to a lathe. In this context, VB, Ra and sensorial data were evaluated to observe the effects of machining parameters. After that, an RSM (Response Surface Methodology)-based optimization approach was applied to the measured variables. Cutting force (97.8%) represented the most reliable sensor data, followed by the AE (95.7%), temperature (92.9%), vibration (81.3%) and current (74.6%) sensors, respectively. RSM provided the optimum cutting conditions (at vc = 150 m/min, f = 0.09 mm/rev, ap = 1 mm) to obtain the best results for VB, Ra and the sensorial data, with a high success rate (82.5%).

scholarly journals Analysis of CSN 12050 Carbon Steel in Dry Turning Process for Product Sustainability Optimization Using Taguchi Technique

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Melesse Workneh Wakjira ◽  
Holm Altenbach ◽  
Janaki Ramulu Perumalla
Keyword(s):  
Carbon Steel ◽  
Feed Rate ◽  
Removal Rate ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Optimization Approach ◽  
Machining Parameters ◽  
Optimal Parameters ◽  
Signal To Noise

The aim of this research paper is to investigate the machinability of CSN 12050 carbon steel bars using carbide insert tool in order to utilize the optimum cutting parameters by employing Taguchi approach. Experiments have been performed under dry cutting condition using an optimization approach according to Taguchi’s L9(34) orthogonal arrays; signal-to-noise ratio tests are designed. Analysis of variance (ANOVA) was performed to determine the importance of machining parameters on the material removal rate (MRR). The results were analyzed using signal-to-noise ratios (S/N); 3D surface graphs, main effect graphs of mean, and predictive equations are employed to study the performance characteristics. The optimal parameters resulted as A3B2C3 (i.e., cutting speed 275 (m/min), depth of cut 0.35 (mm), and feed rate 0.25 (mm/rev), respectively). In the present study, there is an improvement of 5.22 dB at optimal cutting conditions for each significant MRR response parameters such as cutting speed, depth of cut, and feed rate. With these proposed optimal parameters, it is possible to optimize machinability for product sustainability.

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