Modeling and Control of the In-Situ Thermoplastic Composite Tape-Laying Process

1998 ◽  
Vol 120 (4) ◽  
pp. 507-515 ◽  
Author(s):  
Wei-Ching Sun ◽  
Susan C. Mantell ◽  
Kim A. Stelson
Keyword(s):  
Process Model ◽  
Closed Loop ◽  
Thermoplastic Composite ◽  
Closed Loop Control ◽  
Loop Control ◽  
Modeling And Control ◽  
Composite Tape ◽  
Temperature Feedback ◽  
And Control

In thermoplastic tape-laying with in-situ consolidation, a laminated composite is constructed by the local application of heat and pressure. A moving head, applying heat and pressure, lays down and bonds a new layer to the previously bonded layers (substrate). The temperature at the interface between the top ply and the substrate is critical to achieving interlaminar bonding. Recent research on the in-situ thermoplastic composite tape-laying process has focused on modeling, numerical analysis and experimental analysis, but little research has considered the control of this process. In this work, a method is proposed for modeling and control of in-situ thermoplastic composite tape-laying. The key to the control algorithm is predicting the temperature at the interface between the top ply and the substrate. Based on a process model, a state feedback controller and a state estimator for temperature are designed for closed-loop control using the linear quadratic method. Two different approaches are used to develop the process model for real-time closed-loop control through temperature feedback. In the first approach, a low-order lumped parameter model is constructed from a finite difference scheme. The second approach constructs an empirical model through system identification. The structures of the two models are identical, but the parameters differ. The experimental results have shown that the developed estimator and controller can accurately estimate and control the bonding temperature using temperature feedback indicating that the proposed modeling and control methodology can produce a high quality thermoplastic composite laminate.

Nanometer Range Closed-Loop Control of a Stepper Micro-Motor for Data Storage

2007 ◽  
Author(s):  
Mihai Patrascu ◽  
Stefano Stramigioli ◽  
Meint de Boer ◽  
Gijs Krijnen
Keyword(s):  
Data Storage ◽  
Closed Loop ◽  
Image Data ◽  
Closed Loop Control ◽  
Nanometer Range ◽  
Loop Control ◽  
Modeling And Control ◽  
Stepper Motors ◽  
And Control ◽  
Typical Range

We present a nanometer range, closed-loop control study for MEMS stepper actuators. Although generically applicable to other types of stepper motors, the control design presented here was particularly intended for one dimensional shuffle actuators fabricated by surface micromachining technology. The stepper actuator features 50 nm or smaller step sizes. It can deliver forces up to 5 mN (measured) and has a typical range of about 20 μm. The target application is probe storage, where positioning accuracies of about 10 nm are required. The presence of inherent actuator stiction, load disturbances, and other effects make physical modeling and control studies necessary. Performed experiments include measurements with open- and closed-loop control, where a positioning accuracy in the order of tens of nm or better is obtained from image data of a conventional fire-wire camera at 30 fps.

A novel method of bead modeling and control for wire and arc additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shangyong Tang ◽  
Guilan Wang ◽  
Hao Song ◽  
Runsheng Li ◽  
Haiou Zhang
Keyword(s):  
Additive Manufacturing ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Bead Geometry ◽  
Content Type ◽  
Loop Control ◽  
Modeling And Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
And Control

Purpose Modeling and control of bead geometry in wire and arc additive manufacturing is significant as it affects the whole manufacturing process. The purpose of this paper is to establish an efficient model to control the bead geometry with fewer experiments in wire and arc additive manufacturing (WAAM). Design/methodology/approach A multi-sensor system is established to monitor the process parameters and measure the bead geometry information. A dynamic parameters experimental method is proposed for rapid modeling without dozens of experiments. A deep learning method is used for bead modeling and control. To adaptively control the bead geometry in real-time, a closed-loop control system was developed based on the bead model and in situ monitoring. Findings A series of experiments were conducted to train, test and verify the feasibility of the method and system, and the results showed that the proposed method can build the bead model rapidly with high precision, and the closed-loop system can control the forming geometry adaptively. Originality/value The proposed modeling method is novel as the experiment number is reduced. The dynamic parameters experimental method is effective with high precision. The closed-loop control system can control the bead geometry in real-time. The forming accuracy is elevated.

scholarly journals In situ measurement and closed-loop control for powder supply processes

2021 ◽  
Author(s):  
Philipp Peter Breese ◽  
Tobias Hauser ◽  
Daniel Regulin ◽  
Stefan Seebauer ◽  
Christian Rupprecht
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Closed Loop ◽  
In Situ Measurement ◽  
Closed Loop Control ◽  
Loop Control ◽  
Powder Feeder ◽  
Powder Mass

AbstractThe powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

Optimizing anaerobic co-digestion plants: MIR online instrumentation and dynamic real-time substrate feed optimization

2015 ◽  
Vol 63 (7) ◽  
Author(s):  
Daniel Gaida ◽  
Christian Wolf ◽  
Robin Eccleston ◽  
Michael Bongards
Keyword(s):  
Predictive Control ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Control Loop ◽  
Loop Control ◽  
Plant Operation ◽  
Novel Approaches ◽  
The One ◽  
Middle Infrared ◽  
And Control

AbstractClosed-loop control of the substrate feed as well as the application of online instrumentation are important to achieve optimal biogas plant operation. Therefore, this paper presents two novel approaches for online instrumentation and control to achieve optimal AD plant operation based on middle-infrared spectroscopy on the one hand and nonlinear model predictive control on the other hand. At present, research into both techniques is being performed separately, with the intention that in the future the spectroscopic measurements will be integrated into the control loop.

scholarly journals Design and Control of a Piezoelectric-Driven Microgripper Perceiving Displacement and Gripping Force

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 121 ◽  
Author(s):  
Yanru Zhao ◽  
Xiaojie Huang ◽  
Yong Liu ◽  
Geng Wang ◽  
Kunpeng Hong
Keyword(s):  
Pid Controller ◽  
Closed Loop ◽  
Tracking Error ◽  
Closed Loop Control ◽  
Structure Parameters ◽  
Loop Control ◽  
Amplification Ratio ◽  
Gripping Force ◽  
And Control ◽  
Tip Displacement

A piezoelectric-driven microgripper with three-stage amplification was designed, which is able to perceive the tip displacement and gripping force. The key structure parameters of the microgripper were determined by finite element optimization and its theoretical amplification ratio was derived. The tracking experiments of the tip displacement and gripping force were conducted with a PID controller. It is shown that the standard deviation of tracking error of the tip displacement is less than 0.2 μm and the gripping force is 0.35 mN under a closed-loop control. It would provide some references for realizing high-precision microassembly tasks with the designed microgripper which can control the displacement and gripping force accurately.

The Effect of Local Force Control on Punch Forces During Panel Forming

2018 ◽  
Author(s):  
William J. Emblom
Keyword(s):  
Closed Loop ◽  
Force Transducer ◽  
Open Loop ◽  
Control Panel ◽  
Closed Loop Control ◽  
Punch Force ◽  
Blank Holder ◽  
Loop Control ◽  
Operational Envelope ◽  
And Control

Methods for improving the robustness of panel forming including the introduction of process sensing and feedback and control has resulted in significant gains in the quality of parts and reduced failures. Initial efforts in implementing closed-loop control during panel forming used active tool elements to ensure that the total punch force followed prescribed trajectories. However, more recently local forces within the tooling have been demonstrated to not only follow desired force trajectories but have been shown to increase the operational envelope of the tooling compared to open-loop tests and even closed-loop test where the total punch force had been controlled. However, what has not been examined is the effect of local force, especially during closed-loop control panel forming operations on the total punch force measured during forming. This paper addresses this by comparing the results of both open-loop tests and closed-loop tests and examining the effects on both local and total punch forces. It was found that while open-loop forming with various constant draw bead depths resulted in varying total punch forces, once closed-loop control was implemented the total punch forces followed virtually identical trajectories. The tooling for this project included local force transducers and a total punch force transducer. In addition, active draw beads could be controlled during forming and a flexible blank holder with variable blank holder forces were part of the setup.

High Speed Weld Control System of Dual-Bypass MIG Based on LabVIEW

2010 ◽  
Vol 139-141 ◽  
pp. 1852-1855
Author(s):  
Cheng Xue ◽  
Yu Shi ◽  
Ding Fan ◽  
Hao Zhong ◽  
Ming Xiao Shi
Keyword(s):  
Control System ◽  
High Speed ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Mig Welding ◽  
Loop Control ◽  
Weld Formation ◽  
And Control ◽  
Control Output ◽  
Test Result

Dual-bypass MIG welding (DB-GMAW) is a new kind of high speed MIG welding with three arcs. In order to monitor the weld process and control it, a high speed weld system of DB-GMAW was built. The system was run by LabVIEW programs, including getting data of system and control output signals. The test result of system showed that all equipments could be used in the same time. Beside images of weld pool and arc, the weld voltages and currents of every part had been acquired. The signals of bypass current and weld speed also had been input TIG welding sources and worktable motor successfully. Meanwhile, the high speed weld formation had a good quality, and all of these established the closed-loop control of high speed DB-GMAW.

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