Three-Dimensional Tube Geometry Control for Rotary Draw Tube Bending, Part 1: Bend Angle and Overall Tube Geometry Control

2000 ◽  
Vol 123 (2) ◽  
pp. 258-265 ◽  
Author(s):  
Huazhou Lou ◽  
Kim A. Stelson
Keyword(s):  
Process Control ◽  
Control Strategy ◽  
Control Method ◽  
Three Dimensional ◽  
Bend Angle ◽  
Trial And Error ◽  
Operator Experience ◽  
Low Efficiency ◽  
Optimal Process Control ◽  
Tube Geometry

Traditional trial-and-error springback compensation methods have the problems of high scrap rate, low efficiency, high cost of fixtures and operator experience dependency. The method presented in this paper uses on-line measured springback data from the same batch to predict and compensate for springback. Because there are no springback data for the first bend, bend-rebend control is used to make the first bend to eliminate trial tubes. In addition to springback, relaxation and radial growth are also estimated and compensated for to make a bend more accurate. A process control method is developed to optimize the overall control strategy such that the overall tube error is minimized without increasing the required hardware accuracy. The optimal process control strategy has significantly higher accuracy than the traditional trial-and-error method. The details of statistical analysis of tube tolerance and adaptive bend correction algorithm are presented in Part 2 of the paper.

Three-Dimensional Tube Geometry Control for Rotary Draw Tube Bending: Part 1—Bend Angle and Overall Tube Geometry Control

2000 ◽  
Author(s):  
Huazhou Lou ◽  
Kim A. Stelson
Keyword(s):  
Process Control ◽  
Control Strategy ◽  
Control Method ◽  
Three Dimensional ◽  
Bend Angle ◽  
Trial And Error ◽  
Operator Experience ◽  
Low Efficiency ◽  
Optimal Process Control ◽  
Tube Geometry

Abstract Traditional trial-and-error springback compensation methods have the problems of high scrap rate, low efficiency, high cost of fixtures and operator experience dependency. The method presented in this paper uses on-line measured springback data from the same batch to predict and compensate for springback. Because there are no springback data for the first bend, bend-rebend control is used to make the first bend to eliminate trial tubes. In addition to springback, relaxation and radial growth are also estimated and compensated for to make a bend more accurate. A process control method is developed to optimize the overall control strategy such that the overall tube error is minimized without increasing the required hardware accuracy. The optimal process control strategy has significantly higher accuracy than the traditional trial-and-error method. The details of statistical analysis of tube tolerance and adaptive bend correction algorithm are presented in part 2 of the paper.

scholarly journals Multiobjective Optimization Design and Experimental Study of Desulfurization Dust Removal Centrifugal Pump Based on Immune Particle Swarm Algorithm

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yuqin Wang ◽  
Xinwang Huo ◽  
Hailong Ji
Keyword(s):  
Centrifugal Pump ◽  
Optimization Design ◽  
Control Method ◽  
Three Dimensional ◽  
Particle Swarm ◽  
Experimental Results ◽  
Dust Removal ◽  
Particle Swarm Algorithm ◽  
Pump Efficiency ◽  
Low Efficiency

In view of the problems of low efficiency, poor anticavitation performance, and curve hump for current centrifugal pump in the process of desulfurization and dust removal, the desulfurization dust removal centrifugal pump was designed. The velocity coefficient method was used for hydraulic design of centrifugal pump, and the three-dimensional modeling and numerical simulation of flow field of centrifugal pump were carried out by using computational fluid dynamics technology (CFD). The optimal mathematical model with the highest efficiency and the lowest pump net positive suction head NPSHr as the objective function was established under the condition of no curve hump. The immune particle swarm optimization algorithm was used to optimize the multiobjective function, and the optimal combination of the main parameters was obtained. The simulation results showed that, compared with the traditional centrifugal pump, the performance of the optimized centrifugal pump had been greatly improved, which eliminated the phenomenon of curve hump. Based on IH model chemical pump to build a prototype test platform, the experimental results of the external characteristics of the prototype pump and the optimization pump under different working conditions were obtained. At the rated flow rate, the optimization pump efficiency was increased by 13.30%, the head was increased by 11.52%, and NPSHr was decreased by 10.14%. The experimental results showed that the optimized indexes met the design requirements and improved the performance of centrifugal pump. At the same time, the accuracy of the immune particle swarm control method was verified, which provided some reference for the design of desulfurization dust removal centrifugal pump.

Three-Dimensional Tube Geometry Control for Rotary Draw Tube Bending, Part 2: Statistical Tube Tolerance Analysis and Adaptive Bend Correction

2000 ◽  
Vol 123 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Huazhou Lou ◽  
Kim A. Stelson
Keyword(s):  
Three Dimensional ◽  
Tolerance Analysis ◽  
Bend Angle ◽  
Tube Bending ◽  
Process Error ◽  
Process Tolerance ◽  
Bending Process ◽  
Angle Bend ◽  
Geometry Error ◽  
Tube Geometry

The control of each individual bend and overall process is presented in Part 1 of the paper. In Part 2 of the paper, statistical methods are used to analyze and improve 3-D tube bending accuracy. The relationship between bending process error and tube geometry error is obtained with Monte Carlo simulation. For the same tube tolerance requirement, the required process tolerance varies in a large range based on tube geometry. Among the three bending errors: bend angle, bend plane and distance between bends, bend angle error has the largest influence on tube error. For a tube with multiple bends, the overall tube geometry error can be minimized by intentionally modifying the nominal values of the bends to be made based on the errors in the existing bends. The required modification of the bending commands is calculated with an adaptive bend correction algorithm.

A Transfer Function Description of Sheet Metal Forming for Process Control

1991 ◽  
Vol 113 (1) ◽  
pp. 44-52 ◽  
Author(s):  
R. D. Webb ◽  
D. E. Hardt
Keyword(s):  
Transfer Function ◽  
Process Control ◽  
Spatial Frequency ◽  
Sheet Metal ◽  
Closed Loop ◽  
Control Method ◽  
Three Dimensional ◽  
Identification Problem ◽  
Complex Deformation ◽  
Domain Transfer

Three-dimensional forming of sheet metal parts is typically accomplished using one or two shaped tools (dies) that impart the necessary complex curvature and induce sufficient in-plane strain for part strength and shape stability. This research proposes a method of applying closed-loop process control concepts to sheet forming in a manner that automatically converges upon the appropriate tooling design. The problem of controlling complex deformation is reduced to a system identification problem where the die-part transformation is developed as a spatial frequency domain transfer function. This transfer function is simply the ratio of the measured change in spatial frequency content of the part and the die. It is then shown that such a transfer function can be used to implement closed-loop process control via rapid die redesign. Axisymmetric forming experiments are presented that establish the appropriateness of the linear transfer function description (via a test of superposition) and demonstrate the convergence properties of the proposed control method.

Three-Dimensional Tube Geometry Control for Rotary Draw Tube Bending: Part 2—Statistical Tube Tolerance Analysis and Adaptive Bend Correction

2000 ◽  
Author(s):  
Huazhou Lou ◽  
Kim A. Stelson
Keyword(s):  
Three Dimensional ◽  
Tolerance Analysis ◽  
Bend Angle ◽  
Tube Bending ◽  
Process Error ◽  
Process Tolerance ◽  
Bending Process ◽  
Angle Bend ◽  
Geometry Error ◽  
Tube Geometry

Abstract The control of each individual bend and overall process is presented in part 1 of the paper. In part 2 of the paper, statistical methods are used to analyze and improve 3-D tube bending accuracy. The relationship between bending process error and tube geometry error is obtained with Monte Carlo simulation. For the same tube tolerance requirement, the required process tolerance varies in a large range based on tube geometry. Among the three bending errors: bend angle, bend plane and distance between bends, bend angle error has the largest influence on tube error. For a tube with multiple bends, the overall tube geometry error can be minimized by intentionally modify the nominal values of the bends to be made based on the errors in the existing bends. The required modification of the bending commands is calculated with an adaptive bend correction algorithm.

Disorganization of a hole tone feedback loop by an axisymmetric obstacle on a downstream end plate

2014 ◽  
Vol 757 ◽  
pp. 908-942 ◽  
Author(s):  
K. Matsuura ◽  
M. Nakano
Keyword(s):  
Nozzle Exit ◽  
Passive Control ◽  
Control Method ◽  
Three Dimensional ◽  
Acoustic Power ◽  
Shear Layers ◽  
Mean Velocity ◽  
End Plate ◽  
Air Jet ◽  
Practical Engineering

AbstractThis study investigates the suppression of the sound produced when a jet, issued from a circular nozzle or hole in a plate, goes through a similar hole in a second plate. The sound, known as a hole tone, is encountered in many practical engineering situations. The mean velocity of the air jet $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}u_0$ was $6\text {--}12\ \mathrm{m}\ {\mathrm{s}}^{-1}$. The nozzle and the end plate hole both had a diameter of 51 mm, and the impingement length $L_{im}$ between the nozzle and the end plate was 50–90 mm. We propose a novel passive control method of suppressing the tone with an axisymmetric obstacle on the end plate. We find that the effect of the obstacle is well described by the combination ($W/L_{im}$, $h$) where $W$ is the distance from the edge of the end plate hole to the inner wall of the obstacle, and $h$ is the obstacle height. The tone is suppressed when backflows from the obstacle affect the jet shear layers near the nozzle exit. We do a direct sound computation for a typical case where the tone is successfully suppressed. Axisymmetric uniformity observed in the uncontrolled case is broken almost completely in the controlled case. The destruction is maintained by the process in which three-dimensional vortices in the jet shear layers convect downstream, interact with the obstacle and recursively disturb the jet flow from the nozzle exit. While regions near the edge of the end plate hole are responsible for producing the sound in the controlled case as well as in the uncontrolled case, acoustic power in the controlled case is much lower than in the uncontrolled case because of the disorganized state.

scholarly journals Torque Ripple Suppression of PMSM Based on Robust Two Degrees-of-Freedom Resonant Controller

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1015
Author(s):  
Mingfei Huang ◽  
Yongting Deng ◽  
Hongwen Li ◽  
Jing Liu ◽  
Meng Shao ◽  
...  
Keyword(s):  
Control Strategy ◽  
Measurement Errors ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Torque Ripple ◽  
Current Loop ◽  
Two Degrees Of Freedom ◽  
Robust Stability Analysis ◽  
Resonant Controller ◽  
Testing Environments

This paper concentrates on a robust resonant control strategy of a permanent magnet synchronous motor (PMSM) for electric drivers with model uncertainties and external disturbances to improve the control performance of the current loop. Firstly, to reduce the torque ripple of PMSM, the resonant controller with fractional order (FO) calculus is introduced. Then, a robust two degrees-of-freedom (Robust-TDOF) control strategy was designed based on the modified resonant controller. Finally, by combining the two control methods, this study proposes an enhanced Robust-TDOF regulation method, named as the robust two degrees-of-freedom resonant controller (Robust-TDOFR), to guarantee the robustness of model uncertainty and to further improve the performance with minimized periodic torque ripples. Meanwhile, a tuning method was constructed followed by stability and robust stability analysis. Furthermore, the proposed Robust-TDOFR control method was applied in the current loop of a PMSM to suppress the periodic current harmonics caused by non-ideal factors of inverter and current measurement errors. Finally, simulations and experiments were performed to validate our control strategy. The simulation and experimental results showed that the THDs (total harmonic distortion) of phase current decreased to a level of 0.69% and 5.79% in the two testing environments.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

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